EXHIBIT 12.10
-------------------------------
TESTWORK AGREEMENT
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BETWEEN
BIOMIN TECHNOLOGIES S A ("BIOMIN")
AND
CRYSTALLEX INTERNATIONAL CORP.
("CRYSTALLEX")
DATED____________________________ OF ___________________________ , 2004
TABLE OF CONTENTS
PAGE
----
1. DEFINITIONS & INTERPRETATIONS
1.1 DEFINITION 3
1.2 INTERPRETATIONS 4
2. MATERIALS 5
3. TESTWORK & RESULTS 5
4. FUTURE LICENSING 6
5. FEE FOR TESTWORK & PROCESS DESIGN PACKAGE 7
6. CONFIDENTIALITY 8
7. EVENT OF FORCE MAJEURE 8
8. NOTICES 8
9. PROPER JURISDICTION 8
10. GENERAL PROVISIONS 9
SCHEDULES ATTACHED
1. TESTWORK PROCEDURES
2. LICENCE FEE STRUCTURE
3. PROCESS DESIGN PACKAGE
4. CONFIDENTIALITY DEED
5. SCHEDULE OF RATES
6. CRYSTALLEX CONFIDENTIALITY
ANNEXURE 1: TYPICAL LICENCE AGREEMENT
TESTWORK AGREEMENT
BETWEEN: BIOMIN TECHNOLOGIES S.A., a company incorporated in Switzerland and
having its registered office at C/o Progressia Societe de Gestion
SA, Xxx Xx. Xxxxxx 00, Xxxxxxxx 0000, Xxxxxxxxxxx, (hereinafter
known as "BIOMIN")
AND: CRYSTALLEX INTERNATIONAL CORP., a company incorporated in Canada and
having its registered office at 00 Xxxx Xxxxxx, Xxxxx0000, Xxxxxxx,
Xxxxxxx Xxxxxx, X0X 0X0 (hereinafter known as Crystallex)
BACKGROUND:
A. BIOMIN is the owner of a process known as the BIOX(R) Process.
B. Crystallex controls the La Victoria Mine in Bolivar State in Venezuela
and is considering using the BIOX(R) Process, subject to assessing the
results of pilot testwork.
C. BIOMIN agrees to undertake certain testwork on samples of ore or
concentrate obtained from the La Victoria Mine, using the facilities
operated by Lakefield Research Africa in South Africa to establish
process design data for a full-scale BIOX(R) plant.
D. The parties have entered into this Agreement to regulate their rights
and obligations in regard to the said testwork and future use of the
BIOX(R) Process, for the treatment of sulphide ore from the La Victoria
Mine.
THE PARTIES AGREE AS FOLLOWS:
1. DEFINITIONS & INTERPRETATION
1.1 DEFINITIONS
In this Agreement, unless the context otherwise requires:
"AGREEMENT" means this Agreement (including the schedules to
it), as it may later be amended or supplemented by the parties
in writing;
"PROCESS DESIGN PACKAGE" means a set of documents, prepared by
BIOMIN or its nominee, consisting of a process description,
list of design criteria, process equipment list, process design
specifications, heat balance, process control philosophy,
process flow diagrams, mass balances and provisional piping,
valve and instrument diagrams in respect of a plant operating
the BIOX(R) Process provided in accordance with Schedule 2;
"BUSINESS DAY" means a day on which the banks are open for
commercial business in the place specified in the provisions in
which the expression occurs or (if none) in the place or places
where performance of the provision is to take place;
"BIOX PLANT" means all components and equipment of the
processing plant to be constructed in accordance with the
Process Design Package.
"BIOX(R) PROCESS" means a process owned by BIOMIN whereby
micro-organisms are used in the oxidation of certain gold
bearing sulphidic minerals in order to facilitate gold recovery
and the know-how pertaining to such a process;
"CONCENTRATE" means the product produced after run of mine ore
or gold and sulphide bearing rocks from the La Victoria Mine
that has been processed through a froth flotation process;
"EVENT OF FORCE MAJEURE" means the occurrence of an event or
circumstance beyond the reasonable control of the party
affected by it; without limiting the above it includes:
(a) a war (declared or undeclared), insurrection, civil
commotion, military action or an act of sabotage or
vandalism;
(b) a strike, lockout or industrial action, dispute or
disturbance of any kind;
(c) an act of a government or a government authority or
omission of a government or government authority;
(d) an act of God; or
(e) a xxxxx, xxxxxxx, fire, flood, earthquake or other
natural calamity;
"LAKEFIELD LABORATORIES" means Lakefield Research Africa's
laboratories in Johannesburg, South Africa;
"UNITED STATES DOLLARS" OR "US$" means the lawful currency of
the United States of America.
1.2 INTERPRETATION
In the interpretation of this Agreement, unless the context
otherwise requires:
(a) singular includes plural and vice versa;
(b) references to a person include a corporation,
association, partnership, government authority or
other legal entity;
(c) references to writing include any means of
representing or reproducing words, figures,
drawings or symbols, in a visible tangible form;
(d) references to months means calendar months;
(e) references to clauses and schedules refer to
clauses and schedules of this Agreement;
(f) headings are used for convenience only and are to
be disregarded;
(g) where any word or phrase is given a defined
meaning, any other grammatical form of that word or
phrase has a corresponding meaning; and
(h) if any term of this Agreement is legally
unenforceable or made inapplicable, it shall be
severed or read down, so as to maintain (as far as
possible) all other terms of this Agreement (unless
to do so will change the underlying principal
commercial purposes of this Agreement).
2. MATERIALS
2.1 Crystallex is to supply sufficient refractory sulphide ore or
concentrate to the premises of Lakefield Laboratories for
completion of the pilot plant testwork.
2.2 Crystallex will pay for all costs of freight, duties or taxes
imposed by any government in Venezuela or South Africa and all
other costs involved in transporting the ore to Lakefield
Laboratories.
2.3 Until receipt at Lakefield Laboratories, the La Victoria ore
will at all times be at the risk of CRYSTALLEX. BIOMIN
undertakes to take reasonable precautions to ensure the safety
of the ore once received at Lakefield Laboratories but does not
accept any liability for loss of materials, unless through
misconduct or negligence.
2.4 Upon delivery at Lakefield Laboratories, the material supplied
shall become the property of BIOMIN.
3. TESTWORK & RESULTS
3.1 BIOMIN will commence the testwork on the ore received within
one (1) weeks of delivery to Lakefield Laboratories.
3.2 BIOMIN agrees to carry out the testwork in accordance with the
specifications set out in Proposal 2000/00 in Schedule 1. The
results of the testwork will be provided in writing to
CRYSTALLEX in accordance with Proposal 2000/00.
3.3 Progress reports shall be prepared at the end of each calendar
month and forwarded in writing to CRYSTALLEX. The first report
will be available at the end of the first complete calendar
month following the commencement of the testwork.
3.4 A final report shall be prepared in writing and forwarded to
CRYSTALLEX within twenty (20) Business Days of the completion
of the testwork according to the program included in Proposal
2000/00. This report will summarise the results obtained
throughout the testwork program and shall be for the sole and
exclusive use of CRYSTALLEX.
3.5 CRYSTALLEX may, prior to the expiry of a three months, 3-month
term after receipt of the final report, request further tests.
BIOMIN shall receive a fee, to be agreed between the parties at
that time, for any such further testwork unless otherwise
agreed by the parties.
3.6 BIOMIN will provide the necessary back-up power supply to avoid
a system upset that would be detrimental to the test plant and
the test results. This shall be addressed to the satisfaction
of Crystallex, acting reasonably, in Schedule 1, Testwork
Procedures.
4. FUTURE LICENSING
4.1 CRYSTALLEX undertakes that, if it decides to employ a tank
bacterial process for materials obtained from the La Victoria
Mine, it will:
4.1.1 use only the BIOX(R) Process;
4.1.2 seek a Licence Agreement with BIOMIN, the main terms
of which are set out under Clause 4.2 of this
Agreement;
4.1.3 within one (1) year of completion of the testwork,
CRYSTALLEX shall advise BIOMIN in writing of its
decision whether it intends to confirm a Licence
Agreement with BIOMIN for the use of the BIOX(R)
Process
4.2 The Licence Agreement referred to in clause 4.1 will include the
following provisions: (Pro-forma copy attached in Annexure 1)
4.2.1 In return for the right to use the BIOX(R) process
for the LA VICTORIA project and for the know-how
associated with the technology, CRYSTALLEX will pay
to BIOMIN a lump sum license fee plus an ongoing
royalty as is set out in the Licence fee and royalty
payment structure in Schedule 2
4.2.2 Within two (2) weeks of the date of the signing of
the Licence Agreement BIOMIN shall provide to
CRYSTALLEX a Process Design Package in accordance
with Schedule 3. This will be subject to CRYSTALLEX
providing the following key project parameters:
(i) Proposed feed rate to the BIOX(R) plant;
(ii) Gold, silver, sulphur and arsenic grade of
the proposed feed material to the BIOX(R)
plant.
(iii) Meteorological information, like the
average atmospheric pressure, maximum wet
bulb and dry bulb temperatures of the XYZ
gold plant.
4.2.3 BIOMIN or its nominee will provide consultancy to
CRYSTALLEX at mutually agreed times upon written
request from CRYSTALLEX and at CRYSTALLEX'S cost,
for assistance in using the Process Design Package.
Assistance shall be within four (4) working days on
receipt of the request by fax or E-Mail subject to
the availability of flights.
4.2.4 Any consultancy provided to CRYSTALLEX by BIOMIN
shall be at ruling man-day rates plus all reasonable
accommodation, meals, travel costs and expenses
incurred. The aforesaid costs shall be charged at
the rates set in Schedule 5.
4.2.5 Mutually acceptable performance guarantees in
respect of the BIOX(R) plant capacity and efficiency
will be developed. The performance will be tested by
way of a performance guarantee run of fourteen (14)
continuous days once the plant is in stable
operation
4.2.6 Up to a limit of 100% of the total technology fee
and five years royalties to a maximum of 300 000
ounces payable to BIOMIN will be applied (if
required) by BIOMIN in man hours in order to rectify
design deficiencies should the plant not meet
performance guarantees.
4.2.7 All new inventions, improvements and developments
with respect to the BIOX(R) process will be promptly
disclosed to each other by BIOMIN and CRYSTALLEX.
CRYSTALLEX will be able to use such inventions,
improvements and developments at the BIOX(R) plant
and at any of its Operations and future projects
without the payment of additional fees to BIOMIN or
being compensated by BIOMIN for it.
4.2.8 To the best of Biomin's knowledge and belief, the
use of the BIOX(R) Process by Crystallex will not
infringe any patent, trade xxxx or other proprietary
right of any other person. Biomin warrants that it
holds the patent relating to the BIOX(R) Process and
is the registered owner of the BIOX(R) trademark.
If the use of the BIOX(R) Process by Crystallex
results in any claim against Crystallex for any
infringement of any patent, trade xxxx, design or
any other proprietary right which is registered or
protected in any jurisdiction, Crystallex and Biomin
shall confer and co-operate with respect to the
disposition of such claim. If any such claim results
in any legal action against Crystallex:
(i) CRYSTALLEX shall deal with such claim in
accordance with Biomin's instructions, subject
to being placed in funds by Biomin to meet all
costs associated with complying with those
instructions, due regard being had to
Crystallex's best interests; and
(ii) Biomin shall, at CRYSTALLEX's request, render
every reasonable assistance to CRYSTALLEX in
the defence of such legal action, including
without limitation by furnishing to CRYSTALLEX
any evidence and information in Biomin's
possession or control which may reasonably be
used to defeat such claim; and
(iv) If, as a result of such legal action,
CRYSTALLEX is prevented from using the BIOX(R)
Process absolutely or unless a licence fee is
paid by it to the plaintiff or claimant in such
action, then CRYSTALLEX shall be entitled to
terminate the Licence Agreement.
4.2.9 (i) CRYSTALLEX shall not allow any person,
other than its employees, consultants and
contractors, written consent by Biomin, to
visit the BIOX(R) plant without written
consent of Biomin.
(ii) CRYSTALLEX will allow Biomin, its
representatives and potential clients to
visit the plant on reasonable notice, at its
own cost and during ordinary business hours.
5. FEE FOR TESTWORK AND PROCESS DESIGN PACKAGE
5.1 CRYSTALLEX shall pay to BIOMIN the fees as specified in
Schedules 1 and 2.
5.2 The fees referred to in clauses 3 and 4.2 will be invoiced to
CRYSTALLEX at the following times:
5.2.1 monthly for testwork specified in Schedule 1, with
the installments relating to progress of work as
indicated by the report referred to in clause 3.3;
5.2.2 upon receipt of the Process Design Package referred
to in Clause 4.2.2.
5.2.3 Payment of these invoices by CRYSTALLEX shall be
made within twenty-eight (28) days of the date of
receipt of the invoice.
6. CONFIDENTIALITY
Simultaneously with the execution of this Agreement, CRYSTALLEX and
BIOMIN will execute a confidentiality deed a copy of which is attached
in Schedule 4 and Confidentiality of Crystallex attached in Schedule 6.
7. EVENT OF FORCE MAJEURE
7.1 If any party is prevented, hindered or delayed from performing
any of its obligations under this Agreement (other than an
obligation to pay money) by an Event of Force Majeure, that
party shall be excused from performance of such obligation to
the extent it is so prevented, hindered or delayed, and the
time for performance of such obligation shall be extended
accordingly.
7.2 A party affected by an Event of Force Majeure shall immediately
notify the other parties of its occurrence and its effect or
likely effect, and (subject to clause 7.3) use all reasonable
endeavours to minimise the effect of the Event of Force Majeure
and to bring it to an end.
7.3 No party shall be obliged to settle any strike or other
industrial action, dispute or disturbance of any kind, except
on terms wholly satisfactory to it.
8. NOTICES
8.1 Any notice or other communication in connection with this
Agreement is taken to have been duly given when made in writing
and delivered or sent by courier or facsimile to the party to
which such notice or communication is intended to be given, and
shall be addressed to the address of the applicable party as
set out in the heading of this Agreement, or to such other
address or facsimile number as from time to time be notified in
writing by one party to the other for the purpose of this
clause.
8.2 Any notice or other communication sent by facsimile
transmission or courier is taken to have been received upon
completion of an apparently successful transmission to the
recipient or official acceptance of receipt from courier
company. However, if a facsimile is transmitted on a Business
Day after 5.00 pm (at the place of receipt) or on a day which
is not a Business Day, it shall be deemed to have been received
on the next Business Day.
9. PROPER JURISDICTION
9.1 This Agreement is governed by and shall be construed in
accordance with the laws of the Province of Ontario, Canada and
with the non-exclusive jurisdiction of the Ontario courts.
10. GENERAL PROVISIONS
10.1 This Agreement may be signed in any number of counterparts with
the same effect as if the signature to each counterpart were on
the same instrument.
10.2 This Agreement (and any confidentiality deed entered into under
Clause 6) constitutes the entire Agreement between the parties
relating in any way to its subject matter.
10.3 Save as herein provided neither party shall assign its rights
or obligations pursuant to this agreement without obtaining the
prior written consent of the other party, which consent shall
not unreasonably be withheld.
SIGNED AT ______________________ ON ____________________________ 2004
FOR BIOMIN TECHNOLOGIES SA
SIGNATORY:
CAPACITY:
AUTHORITY:
WITNESS
SIGNED AT _____________________ ON __________________________________ 2004
FOR: CRYSTALLEX
SIGNATORY:
CAPACITY:
AUTHORITY:
WITNESS
[Schedules 3-6 omitted]
SCHEDULE 1
----------
TESTWORK PROCEDURES
Gold Fields Project Proposals:
PROP 2003/22-Rev02 - Flotation
PROP 2003/23-Rev01 - BIOX(R) BAT Tests
PROP 2003/24-Rev01 - Continuous BIOX(R) Pilot Plant Test
SUMMARY TABLE OF COSTS ASSOCIATED WITH TESTWORK
-----------------------------------------------
PROPOSAL NUMBER DESCRIPTION COST (US$) NOTES
--------------- ----------- ---------- -----
GFL 2003/22-Rev02 Flotation Work 37,223.00
GFL 2003/23-Rev01 Batch BIOX(R) Tests 4,828.00 1
GFL 2003/24-Rev01 Continuous BIOX(R) testwork 256,980.00 2
Total 299,031.00
NOTES: 1 This cost will apply when the Batch BIOX(R) tests are performed at
------ the same time and on the same sample as the Continuous BIOX(R)
pilot plant.
2 This cost already include a contingency of US$23,360.00
[GRAPHIC OMITTED]
TECHNICAL DIVISION - BIOX(R) DEPARTMENT
PROJECT PROPOSAL
----------------
PROPOSAL NUMBER: GFL 2003/22 - Rev02
---------------
PROJECT CODE: Crystal
--------
DATE: 2 February 2004 VALID UNTIL: 2 April 2004
--------------- ------------
FOR: Crystallex International Corporation
------------------------------------
ATT: Xx Xxxxxxx X Xxxxxx- Chief Operating Officer
-------------------
xxxxxxxxx@xxxxxxx.xx
--------------------
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PILOT PLANT FLOTATION TESTWORK ON A GOLD BEARING SAMPLE
FROM THE LA VICTORIA PIT
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1. INTRODUCTION
------------
This proposal outlines the scope of work and cost involved for the
flotation of a bulk refractory gold concentrate sample from an ore
sample from the La Victoria Pit in Venezuela. Approximately 1.0 ton of
flotation concentrate is required for down-stream BIOX(R) pilot plant
testwork. In addition to thiS approximately 60kg of concentrate will be
required for inoculation build-up. The 60 kg lead sample will be
produced before the bulk flotation. This will reduce the overall
schedule of the testwork.
2. SAMPLE RECEPTION AND PREPARATION
--------------------------------
The samples as received will be air-dried, crushed to less than 6mm,
blended and prepared for milling and flotation testing. A sub-sample of
approximately 25kg will be removed for bench-scale laboratory flotation
testing.
Two to 3 tons of the material will be required to commission the pilot
milling circuit to obtain the specified grind. Based on the current
available information approximately 15 to 20 tons of ore will be
required to produce a 1 ton final concentrate sample.
3. FLOTATION TESTWORK
------------------
The objective of the testwork will be to produce a rougher concentrate
of approximately 1 ton in mass for downstream testwork. The testwork
will be completed in 3 phases:
3.1 Laboratory Milling Curve
------------------------
A milling curve will be conducted on the sample. This will allow us to
predict the time required to obtain a specific grind for the laboratory
float tests. The client will provide the target grind.
3.2 Bench-Scale Flotation Testwork
------------------------------
Laboratory batch flotation tests will be carried out at the specified
grind. These tests will be conducted to confirm the reagent suite
provided. Provision will be made for a total of five scoping tests in
the case of the target grades and recoveries not being met at the
specified grind and reagent suite.
The flotation products will be analysed for Au and S2.
3.3 Pilot Plant Flotation Testwork
------------------------------
Once the flotation response has been confirmed in the laboratory, a
piloting campaign will be conducted on the sample to produce
approximately 1.1 ton of concentrate. All the streams will be sampled
during the campaign to produce a flotation mass balance.
Each sample will be prepared for analysis and analysed for Au and S2.
4. COSTS
-----
Item Description Total (US$)
--------------------------------------------------------------------------------
1 Sample Preparation 7,246
--------------------------------------------------------------------------------
2 Flotation: 22,730
Scoping Tests
Commissioning
Pilot campaign + sampling
Product preparation
Analyses
--------------------------------------------------------------------------------
3 Sample Disposal 2,899
--------------------------------------------------------------------------------
4 Management, Data interpretation & Reporting-LRA 4,348
TOTAL 37,223
================================================================================
All costs as indicated per activity. All costs are exclusive of VAT.
5. DURATION
--------
The final results from this full investigation will be approximately
4-5 weeks. In addition the test program will only commence once a
receipt of the order number has been made available.
6. SAMPLE REQUIREMENTS
-------------------
Fifteen to 20 tons of ore will be required to complete the scope of
work described in Section 3 and produce approximately 1 ton of
concentrate for BIOX(R) pilot plant testwork.
ADDRESS FOR DELIVERY OF SAMPLES
-------------------------------
All samples must be sent to the following address:
SGS SGS Lakefield Research Africa (Pty) Limited
Attention: Mr Xxxx Xxxxxx
00 Xxxxxxx Xxxxxx
Xxxxxxxx
Xxxxxxxxxxxx, 0000
Xxxxx Xxxxxx
Tel: x00 00 000 0000
Fax: x00 00 000 0000
7. REPORTING
---------
All preliminary results will be tabulated and conveyed via a fax /
e-mail as they become available with the final results being detailed
in a confidential document on completion of the test programme.
8. CONDITIONS OF ACCEPTANCE
------------------------
This proposal is valid for a period of 60 days from this date. In the
event that additional information or revisions are required please
contact the undersigned.
This work will commence upon written approval to proceed: The
authorisation to proceed should include the name and address of the
responsible person for invoicing, as well as the order number.
All correspondence related to the proposed testwork should be addressed
to:
GFL Mining Services Ltd
Attention: Jan van Niekerk
00 Xx Xxxxxxx Xxxx
Xxxxxxxx, 0000
Xxxxx Xxxxxx
Tel: x00 00 000 0000
Fax: x00 00 000 0000
E-mail: xxxx@xxxxxxxxxx.xx.xx
X X xxx Xxxxxxx P C van Aswegen
MANAGER: BIOX(R) SENIOR MANAGER: BIOX(R)
PROPOSAL NUMBER: PROP 2003/22 - Rev02
---------------
--------------------------------------------------------------------------------
PILOT PLANT FLOTATION TESTWORK ON A GOLD BEARING SAMPLE
FROM THE LA VICTORIA PIT
--------------------------------------------------------------------------------
ACCEPTED:
---------
Name: .............................................
Signed:............................................
Order No. ........................................
For (Customer): ..................................
Date: ............................................
Invoice details: .................................
[GRAPHIC OMITTED]
TECHNICAL DIVISION - BIOX(R) DEPARTMENT
PROJECT PROPOSAL
----------------
PROPOSAL NUMBER: GFL 2003/23 - Rev01
---------------
PROJECT CODE: Crystal
-------
DATE: 2 February 2004 VALID UNTIL: 2 April 2004
--------------- ------------
FOR: Crystallex International Corporation
------------------------------------
ATT: Xx Xxxxxxx X Xxxxxx- Chief Operating Officer
-------------------
xxxxxxxxx@xxxxxxx.xx
--------------------
--------------------------------------------------------------------------------
BIOX(R) AMENABILITY TESTING OF A REFRACTORY GOLD CONCENTRATE
SAMPLE FROM THE LA VICTORIA PIT, VENESUELA
--------------------------------------------------------------------------------
1. INTRODUCTION
------------
BIOX(R) is a biohydrometallurgical process developed for
pre-cyanidation treatment of refractory gold oreS or concentrates. The
BIOX(R) bacterial culture is a mixed culture of Thiobacillus
ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans.
The BIOX(R) process comprises contacting refractory sulphide ROM ore or
concentrate with a strain of the BIOX(R) bacterial culture for a
suitable treatment period under an optimum operating environment. The
bacteria oxidise the sulphide minerals, thus liberating the occluded
gold for subsequent recovery via cyanidation.
Under controlled continuous plant conditions, the number of bacterial
cells and their activity is optimised to attain the highest rate of
sulphide oxidation. The bacteria require a very acidic environment (pH
1.0 to 2.0), a temperature of between 30 and 45 (degree)C, and a steady
supply of oxygen and carbon dioxide for optimum growth and activity.
The unusual operating conditions for the BIOX(R) bacteria are not
favorable for the growth of most other microbes, thus eliminating the
need for sterility during the BIOX(R) process. Due to the fact that
organic substances are toxic to the BIOX(R) bacteria, they are
non-pathogenic and incapable of causing disease. The bacteria employed
in the BIOX(R) process do not, therefore, pose a health risk to humans
or any animals.
The bacterial oxidation of iron sulphide minerals produces ferric
sulphate and sulphuric acid, and in the case of arsenopyrite, arsenic
acid is also produced. The arsenic is removed from the BIOX(R) liquor
by co-precipitation with the iron and sulphate in a two stage
neutralisation process. This produces a solid neutralisation
precipitate containing largely calcium sulphate, basic ferric arsenate
and ferric hydroxide. Provided an Fe : As molar ratio of > 3 exists,
the ferric arsenate is sufficiently insoluble and stable to allow the
neutralisation product to be safely disposed of on a slimes dam. The
neutralisation liquor, purified to contain an acceptable level of
arsenic, can be re-used in the milling, flotation or BIOX(R) circuits.
The proposed batch BIOX(R) amenability tests on the refractory
concentrate will indicate the relationship between gold dissolution and
sulphide oxidation.
2. OBJECTIVES
----------
(i) To determine the acid/lime requirements of the concentrate
during batch BIOX(R) treatment.
(ii) To determine the sulphide oxidation and gold recovery for the
concentrate after BIOX(R) treatment periods of 5, 10, 15, 20 and
30 days and to compare the gold recovery to that obtained by
direct cyanidation.
(iii) To conduct limited cyanidation optimisation testwork on BIOX(R)
product samples.
(iv) To determine the settling rate and specific settling area
requirements for solid/liquid separation of BIOX(R) product.
(v) To determine the efficiency of arsenic removal and reagent
consumption during batch neutralisation of BIOX(R) liquor.
(vi) To determine the stability of arsenic precipitates formed during
neutralisation of the BIOX(R) liquor.
(vii) To determine the suitability of the on-site water supply for use
in the BIOX(R) circuit.
3. SCOPE OF WORK
-------------
3.1 Feed Characterisation
---------------------
(ii) The concentrate sample will be prepared for direct cyanidation
and BIOX(R) amenability tests. It will be dried, screened,
milled to the required fineness of grind (if necessary) and
split into representative samples.
(iii) Sub-samples of the bulk concentrate will be submitted for size
analyses, mineralogical investigation and the following chemical
analyses: Au(g/t), Ag(g/t), Fe(T), S(T), S(sulphide), S(Degree),
As, C(T), C(organic), CO32- and ICP scan.
(iv) A suitable strain of the BIOX(R) culture will be adapted to the
concentrate.
(v) A direct cyanidation xxxxx test will be conducted on the
concentrate sample.
(vi) A full ICP analysis will be carried on the site water and
toxicity tests performed to determine whether elements
potentially toxic to the BIOX(R) bacterial culture are present
in concentrations that will affect the growth and activity of
the bacteria.
3.2 Batch Amenability Tests
-----------------------
(i) Seven batch BIOX(R) amenability tests will be conducted on the
concentrate. The tests will be performed under the following
standard conditions.
L/S ratio: 4/1
Medium: 9 K or 0 K
Inoculum: 10% (v/v)
pH: Maintained at pH 1.4 - 1.8 by addition of
acid/lime
Duration: 5, 10, 15, 20, 25 day retention periods and
maximum sulphide oxidation. Duplicate tests
will be performed for the maximum sulphide
oxidation test.
Monitoring: Daily pH, Redox and Fe(2+)/Fe(3+) titrations.
At the end of the treatment period for each batch test, the
slurry will be filtered and the BIOX(R) products dried,
crushed and screened.
(ii) BIOX(R) products samples will be submitted for the following
chemical analyses: Au(g/t), Ag(g/t), Fe(T), S(T), S(sulphide),
S(Degree), As, C(T), C(organic) and CO3(2-).
(iii) BIOX(R) liquor samples will be analysed for Fe(T), S(T), and
As.
(iv) Cyanidation tests will be performed on the BIOX(R) product
samples under standard conditions. Xxxxx residues will be
assayed for gold.
3.3 Neutralisation Tests
--------------------
(i) To batch neutralisation test will be conducted on the BIOX(R)
liquor obtained from the batch amenability tests. One test
will be conducted using only limestone as neutralising reagent
(either from a local source or AR-grade) raising the pH to
5.0. The second test will be conducted in two stages: during
stage I the pH will be raised to 5.0 by the addition of
limestone from a local source or AR-Grade, and during stage II
lime will be used to increase the pH further to 7 to 8.
Reagent consumption will be recorded accurately.
(ii) Arsenic stability tests will be performed on the precipitates
formed during neutralisation. The tests will be conducted
according to the standard TCLP (Toxicity Characteristic
Leaching Procedure) test procedure and the multiple extraction
method adopted by the EPA (Environmental Protection Agency) of
the USA.
4. COSTS
-----
A breakdown of costs for the testwork is presented below.
-----------------------------------------------------------------------------------
Item Description US$
----------------------------
Mandays Analyses Total
-----------------------------------------------------------------------------------
1 Sample preparation 435 -- 435
2 Sample charaterisation -- 290 290
3 Mineralogical Investigation 1,739 -- 1,739
4 Inoculum build-up 1,014 -- 1,014
5 Direct cyanidation of concentrate 174 7 180
6 ICP analyses - site water -- 94 94
7 Toxicity tests - site water 580 -- 580
8 Batch tests (7 tests) 3,043 -- 3,043
9 BIOX(R) product analyses -- 913 913
10 Cyanidation of BIOX(R) products 1,217 46 1,263
11 Batch neutralisation tests 580 580 1,159
12 Settling Tests 290 -- 290
13 Project Management - LRA 2,899 -- 2,899
-----------------------------------------------------------------------------------
SUB-TOTAL: FULL BAT TESTS 11,971 1,929 13,900
-----------------------------------------------------------------------------------
Contingency @ 10% 1,197 193 1,390
-----------------------------------------------------------------------------------
TOTAL 13,168 2,122 15,290
===================================================================================
Note: 1. The contingency will only be used after mutual agreement between
----- SGS LAKEFIELD Research Africa (Pty) Ltd. and GFL Mining Services
Limited.
5. DURATION
--------
The proposed testwork program will require a minimum period of three
months to complete. A schedule will be issued once the concentrate
sample has been received.
6. SAMPLE REQUIREMENTS
-------------------
A minimum of 10 kg of fresh flotation concentrate is required for the
direct cyanidation and BIOX(R) amenability testwork. In the case where
a local source of limestone is to be tested approximately 2.5 kg of the
limestone will be required.
Address for delivery of samples
-------------------------------
All samples must be sent to the following address:
SGS SGS Lakefield Research Africa (Pty) Limited
Attention: Mr Xxxx Xxxxxx
00 Xxxxxxx Xxxxxx
Xxxxxxxx
Xxxxxxxxxxxx, 0000
Xxxxx Xxxxxx
Tel: x00 00 000 0000
Fax: x00 00 000 0000
7. CONDITIONS OF ACCEPTANCE
------------------------
This proposal is valid for a period of 60 days from this date. In the
event that additional information or revisions are required please
contact the undersigned.
This work will commence upon written approval to proceed: The
authorisation to proceed should include the name and address of the
responsible person for invoicing, as well as the order number.
All correspondence related to the proposed testwork should be addressed
to:
GFL Mining Services Ltd
Attention: Jan van Niekerk
00 Xx Xxxxxxx Xxxx
Xxxxxxxx, 0000
Xxxxx Xxxxxx
Tel: x00 00 000 0000
Fax: x00 00 000 0000
E-mail: xxxx@xxxxxxxxxx.xx.xx
X X xxx Xxxxxxx P C van Aswegen
MANAGER: BIOX(R) SENIOR MANAGER: BIOX(R)
PROPOSAL NUMBER: PROP 2003/23 - Rev1
---------------
TITLE:
------
--------------------------------------------------------------------------------
BIOX(R) AMENABILITY TESTING OF A REFRACTORY GOLD CONCENTRATE
SAMPLE FROM THE LA VICTORIA PIT, VENESUELA
--------------------------------------------------------------------------------
ACCEPTED:
---------
Name: ........................................................
Signed:.......................................................
Order No. ...................................................
For (Customer): .............................................
Date: .......................................................
[GRAPHIC OMITTED]
TECHNICAL DIVISION - BIOX(R) DEPARTMENT
PROJECT PROPOSAL
----------------
PROPOSAL NUMBER: GFL 2003/24 - Rev01
---------------
PROJECT CODE: Crystal
-------
DATE: 2 February 2004 VALID UNTIL: 2 April 2004
--------------- ------------
FOR: Crystallex International Corporation
------------------------------------
ATT: Xx Xxxxxxx X Xxxxxx- Chief Operating Officer
-------------------
xxxxxxxxx@xxxxxxx.xx
--------------------
--------------------------------------------------------------------------------
BIOX(R) PILOT RUN ON A BULK CONCENTRATE SAMPLE FROM
THE LA VICTORIA PIT, VENEZUELA
--------------------------------------------------------------------------------
1. INTRODUCTION
------------
This proposal outlines the scope and costs for a continuous BIOX(R)
pilot run on a bulk flotatioN concentrate sample from the La Victoria
Pit. This work will provide the necessary data for designing the
commercial bacterial oxidation treatment plant. In addition to this,
the pilot run will confirm the amenability of the material to
continuous biooxidation.
The testwork will be conducted on the premises of SGS Lakefield
Research Africa in Johannesburg in a 120 litre mini-plant, consisting
of four continuously stirred tank reactors (CSTR's). The pilot run will
be conducted under conditions of controlled feed rate, feed density,
pH, temperature, dissolved oxygen and nutrient supply.
Batch cyanidation tests will be conducted on BIOX(R) product
overflowing from the final reactor as well aS on inventory samples
taken from each reactor. Cyanidation optimisation tests will also be
performed to establish the optimum conditions for gold recovery
Additional test work on various process slurries will include
solid/liquid separation tests to determine the optimum settling rates
and flocculant addition rates. Batch and continuous neutralisation
tests will be conducted on BIOX(R) liquor samples. Limestone and/or
flotation tailings will be used tO neutralise the liquor and generate
an environmentally stable ferric arsenate precipitate and liquor that
is toxin free and suitable for recycling to the BIOX(R) plant. Standard
Toxicity CharacterisatioN Leaching Procedure (TCLP) tests will be
performed on the precipitates formed during neutralisation to ensure
that the waste products conform to US Environmental Protection Agency
(EPA) standards for land disposal.
2. OBJECTIVES
----------
The objectives of the test program can be summarised as follows:
(i) To confirm the amenability of the bulk the La Victoria Pit
concentrate to the BIOX(R) process.
(ii) To adapt the bacterial culture further under continuous BIOX(R)
conditions, thereby improving itS performance.
(iii) To determine process data for the designing of the bacterial
oxidation treatment plant.
(iv) To ensure that waste products from the process are
environmentally acceptable.
(v) To establish the optimum cyanidation conditions for recovering
gold from the BIOX(R) product.
(vi) To determine the optimum reagent consumptions during
biooxidation, counter-current decantation, neutralisation and
cyanidation of the BIOX(R) product.
3. SCOPE OF WORK
-------------
SAMPLE PREPARATION
------------------
Two concentrate samples will be received for the pilot plant test work.
The LEAD sample (~150 kg) will be received approximately 35 days before
the arrival of the BULK sample. The lead sample will be of
approximately the same characteristics as the bulk sample and will be
used to start the inoculum build-up phase.
LEAD SAMPLE
-----------
i. The lead sample will be dried at a temperature below
60 (Degree)C if required.
ii. A sub-sample will be submitted for particle size analyses. If
the particle size is coarser than the 80 % - 75 um and 95 % -
150 um specified for BIOX(R) then the sample will be remilled to
thesE specifications.
iii. The sample will be screened through an 850 um screen to remove
any lumps.
iv. The sample will be split into representative sub-samples using a
rotary splitter.
v. A sub-sample will be submitted for the following analyses:
o Au, S(T), S(2-), S(0), As, Fe, C(org), CO(3), Si
BULK SAMPLE
-----------
i. The bulk sample will be dried (Temp < 60(Degree)C) if required.
ii. A sub-sample will be submitted for particle size analyses. If
the particle size is coarser than the 80 % - 75 um and 95 % -
150 um specified for BIOX(R) then the sample will be remilled to
these specifications.
iii. The sample will be screened through an 850 um screen to remove
any lumps.
iv. The sample will be split into representative sub-samples using
an 8 bucket rotary splitter. The bags will be clearly labelled
and stored in a designated trunk. Each of the bags will be split
again using a rotary splitter before being used as feed to the
pilot plant.
v. A sub-sample will be submitted for the following analyses:
o Au, S(T), S(2-), S(0), As, Fe, C(org), CO(3), Si
o Particle size analyses
o Full mineralogical analyses with gold deportment
o Full ICP scan
vi. A series of direct cyanidation tests will also be performed on
selected concentrate samples. The direct cyanidations will
indicate the gold dissolution achievable without any
pre-oxidation treatment. The tests will be performed using a
bulk cyanide addition of 20 kg/t and the gold dissolution and
reagent consumption will be determined at the end of the 24 hour
xxxxx.
VARIABILITY BATCH AMENABILITY TESTS
-----------------------------------
The following work is included in the Variability BAT tests:
(i) The conditions for the batch BIOX(R) amenability tests are given
below:
L/S ratio: 4/1
Medium: 9 K or 0 K
Inoculum: 10% (v/v) using inoculum from the pilot plant
primary reactor
pH: Maintained at pH 1.4 - 1.8 by addition of
acid/lime
Duration: 80 % and/or maximum oxidation (2x)
Monitoring: Daily pH, Redox and Fe(2+)/Fe(3+) titrations.
At the end of the treatment period for each batch test, the
slurry will be filtered and the BIOX(R) products dried (T < 60
(Degree)C), crushed and screened.
(v) BIOX(R) products samples will be submitted for the following
chemical analyses: Au(g/t), As, Fe(T), S(T), S(sulphide),
S(Degree), Si and CO3(2-).
(vi) BIOX(R) liquor samples will be analysed for Fe(T), S(T), and As.
(vii) The sulphide oxidation rate will be calculated from the
analytical results and specie balances determined for Fe, As
and S.
(viii) Cyanidation tests will be performed on the BIOX(R) product
samples under standard conditions to bE specified by Project
Leader. Xxxxx residue solids will be assayed for gold and xxxxx
residue solutions for SCN and Fe. Final solutions will also be
titrated to determine the free cyanide and CaO concentrations at
the end of the xxxxx. This will be used to determine the reagent
consumptions during the xxxxx. A cyanide balance will also be
determined for each test.
The results of the variability tests will be compared to the results of
the previous BAT tests performed.
BATCH AMENABILITY TESTS (BAT)
-----------------------------
The following work is included in the BAT tests:
(i) The conditions for the batch BIOX(R) amenability tests are given
below:
L/S ratio: 4/1
Medium: 9 K or 0 K
.. Inoculum: 10% (v/v) using inoculum from the pilot plant
primary reactor
pH: Maintained at pH 1.4 - 1.8 by addition of
acid/lime
Duration: 5, 10, 15, 20, 25 and 2 x maximum oxidation
Monitoring: Daily pH, Redox and Fe(2+)/Fe(3+) titrations.
At the end of the treatment period for each batch test, the
slurry will be filtered and the BIOX(R) products dried (T < 60
(Degree)C), crushed and screened.
(ii) BIOX(R) products samples will be submitted for the following
chemical analyses: Au(g/t), As, Fe(T), S(T), S(sulphide),
S(Degree), Si and CO3(2-).
(iii) BIOX(R) liquor samples will be analysed for Fe(T), S(T), and As.
(iv) The sulphide oxidation rate will be calculated from the
analytical results and specie balances determined for Fe, As
and S.
(v) Cyanidation tests will be performed on the BIOX(R) product
samples under standard conditions to bE specified by Project
Leader. Xxxxx residue solids will be assayed for gold and xxxxx
residue solutions for SCN and Fe. Final solutions will also be
titrated to determine the free cyanide and CaO concentrations at
the end of the xxxxx. This will be used to determine the reagent
consumptions during the xxxxx. A cyanide balance will also be
determined for each test.
The results of the variability tests will be compared to the results of
the previous BAT tests performed.
INOCULUM BUILD-UP
-----------------
A LEAD sample of float concentrate will be used for building up
sufficient inoculum to inoculate the 60-litre primary reactor and
commence continuous operation of the BIOX(R) pilot plant. In order to
savE time, the inoculum build-up process will commence approximately 35
days prior to the delivery of the bulk concentrate sample. The
continuous feeding of the pilot plant will proceed with the BULK
concentrate on receipt and preparation of the sample.
A BIOX(R) bacterial culture already adapted to a similar concentrate
will be used for the adaptation anD inoculum phase. The adaptation and
inoculum build-up stages will be carried out as follows:
BENCH INOCULUM BUILD-UP
-----------------------
The adaptation and inoculum build-up stage will be started on the BAT
bench:
i. A 5 litre beaker will be set up containing 3 litres of 9K
nutrient medium. Initially 250 g concentrate will be added and
acid stabilised before adding 10 % v/v active inoculum. The test
will be maintained at 39 - 41 (Degree)C with constant agitation
and aeration.
ii. Daily Fe(2+)/Fe(3+), Redox, pH, temperature and DO measurement
will be carried out on the test.
iii. Further 250 g aliquots of concentrate will be added to the batch
as the bacterial activity increases, indicated by the ferrous
concentration and Redox potential.
iv. Active inoculum from the adaptation phase will be used to set up
four inoculum build-up tests. The tests will be set up in 5
litre beakers containing 3 litres of 9K nutrient medium at 20 %
solids (~ 750 g concentrate).
v. The slurry will be acid stabilised and inoculated with 10 % v/v
inoculum from the adaptation stage.
vi. The same conditions and monitoring methods will be used as for
the adaptation stage.
vii. Two of the tests will be stopped at the end of the bench
inoculum build up phase and used as inoculum for the pilot
plant. One litre of inoculum will also be removed from each of
the remaining two tests, and replaced with fresh concentrate and
nutrient medium.
viii. The two remaining inoculum build-up tests will be kept active on
the bench for the duration of the pilot plant test. These tests
will act as standby inoculum to ensure that an active culture is
always readily available.
PILOT PLANT INOCULUM BUILD-UP
-----------------------------
The primary and first secondary reactors of the pilot plant will be
inoculated once the bacteria in the bench build-up tests are active.
The following procedure will be followed to inoculate these reactors.
i. The primary reactor and first secondary reactor will be filled
with 50 litres and 15 litres of slurry respectively, containing
20 % solids and 0K nutrient medium. The slurry will be pH
stabilised at pH 1.3 - 1.4 and the temperature will be increased
to 40 (Degree)C.
ii. Six litres of active inoculum will be added to the primary
reactor and 2 litres of inoculum to the first secondary reactor.
iii. The same conditions and monitoring methods will be used as for
the bench build-up stage.
iv. The inoculum in the reactors will be allowed to become active
before continuous feeding of the pilot plant commences
v. Four litres active inoculum from the primary or first secondary
reactor will be used to inoculate the second and third secondary
reactors. Continuous feeding of the pilot plant at a 10 day
retention time will commence once the last two secondary
reactors have been inoculated and the inoculum in the primary
reactor is active.
CONTINUOUS OPERATION OF THE PILOT PLANT
---------------------------------------
After inoculum build-up, the plant will be operated continuously for an
approximate period of 14 weeks as tabulated below. Unforeseen problems
in treating the concentrate will obviously extend the period of
operation.
==========================================================
Phase Retention time (days) Duration (Days)
----------------------------------------------------------
A (1) 10 5
A (2) 8 5
A (3) 7 5
----------------------------------------------------------
B 6 24
----------------------------------------------------------
C 5 20
----------------------------------------------------------
D 4 16
==========================================================
The performance of the plant will dictate the duration of each phase of
operation. The main objective of the pilot run is to establish the
optimum retention time to achieve the required sulphide oxidation and
the optimum gold dissolution. These are only approximate durations for
each retention time and may be changed depending on the bacterial
activity
During Phases A to D the plant will be operated under the following
conditions:
Liquid/solid ratio in feed: 4:1
pH: 1.2 to 1.6, controlled by adding
limestone or sulphuric acid
Temperature: 40 to 45 (Degree)C
Aeration Aeration rates set to maintain DO
levels > 2.0 ppm in all reactors The
aeration air will be enriched with CO2
@ 1.5 % by volume
BIOX(R) inventory and overflow product samples will be collected at
regular intervals throughout the tesT program. The samples will be
analysed and then cyanide leached to determine the extent of sulphide
oxidation and the relationship between sulphide oxidation and gold
recovery.
STANDBY POWER
-------------
Standby power in the form of a generator will be available and in
working order at all times during the test program. The generator will
be able to operate the complete pilot plant including all the reactors,
the feed system, the geyser and hot water pump and all instrumentation.
The generator will simultaneously be able to operate the compressor and
the lights in the pilot plant area.
STANDBY TECHNICIAN
------------------
A technician will be on standby at all times during the continuous
operation of the pilot plant. A schedule indicating the technician on
standby as well as the contact details will be made available to the
Project Leader at the start of the continuous phase of the pilot plant.
PLANT OPERATORS
---------------
The pilot plant will be operated by a minimum of 5 plant operators. The
operators will be signed on and administrated by SGS Lakefield
Research. The operators will work full time on the pilot plant under
the supervision of the Project Leader and Project Metallurgist. Four of
the operators will work on the pilot plant and one will be responsible
for cyanidation test work, rotating every month. The operators will
continue working on the pilot plant for a minimum of one week after the
end of the continuous phase.
OVERFLOW SAMPLES
----------------
The daily overflow product from the pilot plant will be weighed and the
volume recorded. The slurry will then be agitated to suspend all
settled solids and split into 8 sub-samples using a rotary slurry
splitter.
A minimum of two of the samples will be weighed and the volume recorded
for density calculation. The samples will then be filtered followed by
a low pH water wash (pH 1.2 using H2SO4) and a water wash. The samples
will be dried (T < 60 (Degree)C), weighed and screened through an 850
um screen to remove any lumps.
The solids from the two samples will be combined and blended.
Representative sub-samples for analyses and cyanidation test work will
be split from the combined sample. The remaining sample will be
labelled and stored in a designated storage area.
The samples will be submitted for the following analyses:
o Solids sample: Au, S(T), S(2-), S(0), As, Fe, CO3(2-), Si.
o Solution samples: S (as SO4), As, Fe
The cyanidation conditions for the standard overflow samples will be
set by the Project Leader as described in the next section.
The remaining 6 slurry samples will also be filtered, acid water washed
and water washed. The washed solids will be dried (T < 60 (Degree)C),
labelled and stored in a designated storage area for cyanidatioN
optimisation and other test work.
INVENTORY SAMPLES
-----------------
Inventory samples will be taken as determined by the Project Leader.
The inventory samples will normally be taken from all the reactors in
the pilot plant, but samples can be taken from only one or more tanks
if required. The procedure for taking inventory samples will be as
follows:
Two types of inventory samples will be taken, small samples (~ 500 ml)
for analyses only and large samples (~ 2 000 ml) for analyses and
cyanidation tests. The large samples will be used to determine both the
extent of sulphide oxidation after different treatment times as well as
the corresponding gold dissolution at the various extent of sulphide
oxidation. The large inventories can, however, not be taken too
regularly as it may influence the stable operation of the plant. The
smaller inventories will be taken to obtain more data on the extent of
sulphide oxidation after various treatment times.
The procedure for taking an inventory sample from a reactor is as
follows:
i. Either a 2 000 ml or 500 ml sample is removed from the sample
port in the middle of the reactor.
ii. The sample is weighed and the volume recorded. The same volume
of water is added to the reactor to maintain a constant
retention time in the pilot plant.
iii. The sample is filtered and washed first with acid water,
followed by potable water. The filter cake is dried (T < 60
(Degree)C), weighed and screened through an 850 um screen to
remove any lumps.
iv. 500 ml inventory: The solids are submitted for the following
analyses: Au, S(2-) and Si.
v. 2 000 ml inventory: Samples for analyses and cyanidation tests
are split out from the dried solids. Samples are submitted for
the following analyses:
o Solids sample: Au, S(T), S(2-), S(0), As, Fe, CO3(2-), Si.
o Solution samples: S (as SO4), As, Fe
vi. Cyanidation tests on the inventory samples will be performed
according to the conditions set by the Project Leader as
described in the next section.
vii. All remaining solid samples will be labelled and stored in a
designated area.
CYANIDATION TEST WORK
---------------------
STANDARD OVERFLOW AND INVENTORY CYANIDATIONS
--------------------------------------------
The inventory and daily overflow samples will be leached using standard
conditions to determine the average gold dissolution that can be
achieved for each phase of the test work. The cyanidation tests will
also indicate the reagent consumptions that can be expected when
leaching the BIOX(R) producT samples. The standard cyanidation
conditions will be adjusted during the test program in order to achieve
the maximum gold dissolution while minimising the cyanide consumption.
On completion of the cyanidation tests the slurry will be filtered and
the solids washed with potable water to remove any entrained solution.
The washed solids will be dried and screened (- 850 um) to remove any
lumps and submitted for Au assay. A sample of the filtrate will be
titrated for free cyanide and CaO to determine the reagent
consumptions. A sample of the filtrate will be submitted for
thiocyanate and total iron analyses.
CYANIDATION OPTIMISATION TEST WORK
----------------------------------
Cyanidation optimisation tests will be conducted throughout the pilot
plant test program in order to determine the conditions for which
optimum gold dissolution is achieved at the lowest reagent consumption.
Composite BIOX(R) product samples will be made for the optimisation
tests using thE remaining overflow samples for selected periods of
continuous pilot plant operation.
The optimisation tests can include the following tests:
o Cyanidation rate tests: The rate test is a series of 8
cyanidation tests, taken off after different times, in order to
determine the rate of dissolution and cyanide
consumption. The results of the test will be used to determine
the staged cyanide addition rates and total cyanidation period
required.
o Different addition rates of cyanide: The standard cyanidation
tests will use staged cyanide addition, with the additions
determined from the cyanidation rate test. Optimisation tests
will be performed at different cyanide addition intervals and
concentrations in solution.
o Pulp density: The effect of pulp density on the gold recovery
and cyanide consumption will be determined.
o Activated carbon addition rate.
o Selected pre-treatments before the cyanide xxxxx, for example
SO2 pre-treatment, milling or attritioning of the BIOX(R)
product and hot-lime treatment.
ADDITIONAL CYANIDATION TESTWORK
-------------------------------
The following test work will be performed in addition to the standard
cyanidation and cyanidation optimisation tests:
o Diagnostic xxxxx tests on selected concentrates and/or BIOX(R)
product samples.
o Cyanidation speciation test work on selected cyanidation residue
samples.
o Carbon adsorption appraisal.
o Determining the xxxxx kinetics and fitting the results to a
model describing the xxxxx kinetics using a rectangular
distribution of reaction rate constants.
o Determining the oxygen uptake rate during cyanidation.
The number of tests to be performed will be determined by the Project
Leader during the pilot plant test program.
SOLID/LIQUID SEPARATION
-----------------------
Laboratory scale settling tests will be conducted on selected slurry
samples to determine the optimum flocculant addition, settling rate and
required thickener area.
The settling test work will involve the following tests:
o Flocculant selection tests
o Flocculant dosage optimisation tests
o CCD simulation tests on BIOX(R) product
o Liquid/solid separation test work conducted by suppliers
Suppliers of liquid/solid separation equipment will also be invited to
perform laboratory test work at SGS Lakefield Research. The cost of
such test work, if any, will fall outside the scope of this proposal
unless it is specifically stated otherwise. SGS Lakefield Research
will, however, give support to the suppliers by providing them with an
area to set up their equipment and conduct their tests as well as other
utilities, for example a connection to the water supply, washing
facilities etc. that may be required for them to complete their test
work. The operators will also be available to the suppliers to perform
small duties, for example drying and weighing of samples etc.
NEUTRALISATION OF ACIDIC BIOX(R) LIQUOR
---------------------------------------
A series of batch and continuous neutralisation tests will be performed
as part of the pilot plant test run. The objectives of the
neutralisation test work are:
1. To prove that the effluent products from neutralisation complies
with environmental legislation guidelines (USA - EPA)
2. To determine the reagent consumption during neutralisation
The USA - EPA standard for land disposal of arsenic bearing wastes
requires the effluent stream to comply with the following standards:
o The liquor must have a dissolved arsenic value of (less than or
equal to) 0.5 ppm
o The solids must have a TCLP extract containing an arsenic
value (less than or equal to) 5.0 ppm
The standard neutralisation circuit uses limestone as first stage
neutralising reagent and lime as second stage neutralising reagent to
ensure an effluent pH > 7.0. A two stage neutralisation circuit is used
to prevent the formation of calcium arsenate, an unstable form of
arsenic. Ferric arsenate is the preferred neutralisation product for
solution containing arsenic and ferric.
The neutralisation test work includes tests with reagent grade
limestone and lime, as well as tests using the limestone and/or lime
source(s) to be used on the commercial plant. Flotation tailings can
also be used as neutralising reagent if the tailings contain sufficient
carbonate minerals.
SAMPLE CHARACTERISATION
-----------------------
The following tests will be performed on the site limestone and lime
samples and on the flotation tailings sample:
i. Acid Capacity Tests: The tests are conducted to determine the
neutralising capacities of the various reagents. The tests are
conducted by the stepwise addition of aliquots of the
neutralising reagent to a stirred beaker containing 3 litres of
a 0.1 M H2SO4 solution. The pH of the solution is measured after
each addition and plotted as a function of the reagent addition.
ii. Chemical Analyses: The reagents will be submitted for the
following chemical analyses: Si, Total CO3, Mg and Ca.
iii. A dried solids sample will be submitted for particle size
analyses.
BATCH NEUTRALISATION TESTS
--------------------------
Laboratory scale batch neutralisation tests will be conducted. The
tests will be conducted in a 5 litre beaker with agitation and
aeration. BIOX(R) liquor from the pilot plant will be diluted at a
ratio oF 2:1, wash water to BIOX(R) solution, to simulate the CCD
washing step. Manual additions of small aliquotS of neutralising
reagent will be made in a stepwise manner until the target pH is
achieved. All reagent additions will be recorded.
The pH of the solution will be recorded after each reagent addition and
sample aliquots removed at various pH's as the reactions progress. The
samples will be immediately filtered and the filtrates submitted for As
and Fe analyses. The samples will also be titrated for ferrous iron.
At the end of the test, the slurry is weighed and the volume recorded.
The slurry is then filtered, the solids washed with potable water, and
the mass of the wet filter cake is recorded. A small portion of the wet
filter cake is taken, weighed and dried to determine the moisture
content of the wet solids. The solids concentration in the neutralised
product is calculated from the data.
The remaining solids will be sealed moist in a plastic bag. Selected
solids samples from the neutralisation tests (batch and continuous)
will be submitted for TCLP analyses and/or solids SG determination.
The reagent additions will be converted to kilogram per ton
concentrate.
CONTINUOUS NEUTRALISATION TESTS
-------------------------------
Continuous neutralisation test work will also be performed using the
continuous neutralisation pilot plant supplied by SGS Lakefield
Research. The objectives of the continuous neutralisation test work are
to prove the efficiency of arsenic removal and the stability of arsenic
precipitates under continuous operating conditions. The tests will also
indicate the reagent consumption during continuous operation.
The pilot plant consists of six 5 litre CSRT reactors in series. Each
reactor is also fitted with an air xxxxxxx and the aeration rate is set
to maintain a DO concentration of 6 - 8 ppm. Diluted acidic liquor from
the BIOX(R) pilot plant will be stored in a feed stock tank and fed to
the first reactor usinG either a peristaltic or a dosing pump. The
neutralisation circuit is usually operated at a retention time of 6
hours (12 hours when flotation tailings are used).
It may be necessary to recycle liquor from the third reactor back to
the first reactor. The rate of slurry recycle will normally be in the
order of 100 to 500 % the feed rate to the plant.
The plant will normally require two stage pH control, using limestone
to pH ~ 5 in the second reactor and lime to pH 7 - 8 in the fifth
reactor. The plant is equipped with agitated limestone and lime make-up
vessels. Reactors 2 and 5 are fitted with on-line pH measurement and
control.
Flotation tailings will also be used as neutralising reagent. The pilot
plant may be fitted with a float tails mixing tank and feeding system
for this purpose. Float tails will be fed to the first neutralisation
reactor.
Stable operation of the neutralisation plant is achieved once all the
reactors are filled, the feed rate is set to give the required feed
rate and the online pH control is operational and maintaining the pH
set points in the specified reactors. The test will continue until
stable operation has been achieved for a minimum of 3 times the
retention time of the plant.
A log sheet will be kept where the following is recorded every hour:
o Plant feed rate of acid liquor (and float tailings).
o Levels for the following tanks: Acid liquor, float tails,
limestone, lime.
o Recycle stream flow rate.
o The following readings will be taken on every reactor: pH,
Redox, DO
o Overflow volume and mass
The last retention time period is used for sampling of the pilot plant.
Three sets of inventory samples will be collected during this period.
The samples will be filtered and the filtrates will be submitted for
total iron and arsenic analyses. Ferrous ion titrations will also be
performed on the filtrates.
The plant overflow samples will be weighed and the volume recorded
before the samples are filtered and washed. The wet filter cakes will
be weighed and a small sample of the filter cakes will be taken,
weighed and dried. The dry solids will be weighed and the solids
content of the overflow slurry calculated. The remaining filter cake
sample will be sealed in a plastic bag and stored in a designated area.
Selected samples may be submitted for TCLP tests.
The last three reactors will also be filtered at the end of the test
run. The solids will be washed and sealed in plastic bags. Selected
samples may be submitted for TCLP tests.
The reagent additions will be converted to kilogram per ton
concentrate.
PHYSICAL PROPERTIES OF PROCESS SLURRIES
---------------------------------------
The following properties will be determined for various process
slurries:
o Viscosity
o Solids density
o Particle size distribution
Two costs are given for the viscosity tests:
1. The total cost for testing BIOX(R) slurry from each of the 4
reactors. The tests will be performed at thE density and
temperature prevailing in the reactor. The full range of shear
rates will be tested.
2. The cost per slurry sample, testing the slurry at 5 different
solids concentrations and over the full range of shear rates.
4. SCHEDULE AND REPORTING
----------------------
A proposed schedule for the test work is given in the proposal, showing
the different phases of BIOX(R) inoculum build-up and continuous
operation as well as the corresponding time frames for cyanidation,
neutralisation and other test work.
The schedule also indicates the time required for performing and
reporting L/S, neutralisation and viscosity tests. All results and
reports will be sent to the Project Leader within the specified period.
Scheduling of additional test work will be done by the Project Leader
in conjunction with SGS Lakefield Research to suit both parties. The
test work must, however, be completed within the period indicated on
the schedule.
A final report will be compiled by the Project Leader and the Project
Metallurgist incorporating all the results from the pilot plant test
work and additional test work. The report will also give the process
implications of the results from the test work in a form suitable to be
used for the design of a commercial BIOX(R) plant.
5. COST
----
The cost for the testwork based on the scope of work defined above is
shown in the table below. Changes in the scope of work will cause a
change in the total cost of the testwork based on the rates given in
the table below.
--------------------------------------------------------------------------------
Item Description Units US$
---------------------
Costs/unit Total
--------------------------------------------------------------------------------
1 Sample milling: Lead sample 1 122 122
Sample milling: Bulk sample 1 2,174 2,174
2 Sample prep and characteration 1 1,413 1,413
3 Inoculum build-up 25 75 1,877
4 Mineralogical investigation 1 1,594 1,594
--------------------------------------------------------------------------------
Toxicity Tests
5 9 K shake flask Tests 0 441 0
6 BAT Tests 0 881 0
--------------------------------------------------------------------------------
Batch Amenability Tests
7 Full Amenability Tests 0 4,828 0
8 Variability Tests 0 1,364 0
--------------------------------------------------------------------------------
Continuious operation phase
9 BIOX(R) pilot plant operation 80 1,447 115,729
10 Overflow & Full inventory analyses 123 134 16,489
Small inv analyses 48 33 1,600
11 Std cyanidation tests 123 22 2,674
--------------------------------------------------------------------------------
Cyanidation optimisation
12 Cyanidation optimisation 35 22 761
13 Cyanidation speciation 15 81 1,217
14 Carbon adsorption appraisal 1 1,449 1,449
15 Diagnostic xxxxx tests 3 725 2,174
16 Cyanidation rate tests (8xtests) 2 255 510
--------------------------------------------------------------------------------
Neutralisation tests
17 Batch neutralisation tests 4 284 1,136
18 Continuous neutralisation tests 2 954 1,907
19 Sample characterisation 3 130 391
20 TCLP tests 6 86 513
--------------------------------------------------------------------------------
Liquid/solid separation tests
21 Floculant selection - per slurry 3 0 0
22 Flocculant optimisation - per slurry 3 0 0
23 CCD simulation tests 2 0 0
--------------------------------------------------------------------------------
Physical properties of process slurries
24 Viscosity measurement - reactors 1 174 174
Viscosity measurement - per slurry 5 174 871
25 Solids density measurement 6 12 70
26 Size analyses 2 39 78
--------------------------------------------------------------------------------
27 Waste disposal 1 11,594 11,594
28 Report preparation - LRA 20 638 12,754
29 Project Managemetn - GFL 100 543 54,348
--------------------------------------------------------------------------------
SUB - TOTAL 233,620
--------------------------------------------------------------------------------
Contingency 23,360
--------------------------------------------------------------------------------
TOTAL 256,980
--------------------------------------------------------------------------------
6. EXCLUSIONS
----------
This proposal will specifically exclude the following:
o Transport, insurance, handling, custom clearance and similar
charges for any of the samples required for the test work.
o Costs for flotation testwork to produce the project samples.
o Continuous cyanidation testwork.
o Cost of vendors invited to test their equipment.
o Call out costs for maintenance technician.
7. SAMPLE REQUIREMENT
------------------
Project Sample (Bulk Concentrate Sample)
----------------------------------------
A bulk 1 000 kg sample of flotation concentrate is required for the
proposed testwork. The sample can be delivered moist or dried (at a
temperature < 60 (Degree)C). The concentrate should have a nominal
grind size of approximately 80 % - 75 um and 95 % - 150 um.
Lead Sample
-----------
A lead sample of approximately 100 kg can be delivered to SGS SGS
Lakefield Research approximately 35 days prior to the delivery of the
bulk sample. The lead sample can then be used for inoculum build-up.
Batch Amenability Test samples
------------------------------
Selected concentrate samples can be submitted for batch amenability
tests. These tests can be used to determine the variability of the ore
with regards to amenability to BIOX(R) treatment and subsequent
cyanidation recovery. 10 kg concentrate is required for a full BAT test
on a specific concentrate sample and 2.5 kg concentrate is required for
a variability BAT test.
Limestone and/or Lime Sample
----------------------------
A 50 kg sample of limestone and/or lime from the source likely to be
used during full-scale operation must be provided for testing in the
BIOX(R) and neutralisation circuits.
Water Sample
------------
A 10 litre sample of water from the source likely to be used as process
water in the full-scale plant must be submitted for toxicity testing.
Flotation Tailings Sample
-------------------------
A 50 kg sample of flotation tailings produced during the flotation
pilot plant run will be required for testwork during the pilot plant
run. Testwork on the flotation tailings include settling tests on a
blend of neutralised BIOX(R) product and flotation tailings and batch
and continuous neutralisation tests.
Address for delivery of samples
-------------------------------
All samples must be sent to the following address:
SGS Lakefield Research Africa (Pty) Limited
Attention: Mr Xxxx Xxxxxx
00 Xxxxxxx Xxxxxx
Xxxxxxxx
Xxxxxxxxxxxx, 0000
Xxxxx Xxxxxx
Tel: x00 00 000 0000
Fax: x00 00 000 0000
8. TESTWORK AGREEMENT
------------------
A Testwork Agreement will be negotiated with Crystallex International
Corporation prior to the commencement of the BIOX(R) pilot run. This
Agreement will contain the following:
o A Confidentiality Deed;
o The deliverables expected from each party during the test
program;
o The main elements of a future licence agreement between
Crystallex International Corporation and Biomin Technologies
S.A., wholly owned subsidiary of Gold Fields Limited and the
owner of the BIOX(R) Technology.
9. CONDITIONS OF ACCEPTANCE
------------------------
This proposal is valid for a period of 60 days from this date. In the
event that additional information or revisions are required please
contact the undersigned.
This work will commence upon written approval to proceed: The
authorisation to proceed should include the name and address of the
responsible person for invoicing, as well as the order number.
All correspondence related to the proposed testwork should be addressed
to:
GFL Mining Services Ltd
Attention: Jan van Niekerk
00 Xx Xxxxxxx Xxxx
Xxxxxxxx, 0000
Xxxxx Xxxxxx
Tel: x00 00 000 0000
Fax: x00 00 000 0000
E-mail: xxxx@xxxxxxxxxx.xx.xx
X X xxx Xxxxxxx P C van Aswegen
MANAGER: BIOX(R) SENIOR MANAGER: BIOX(R)
PROPOSAL NUMBER: PROP GFL 2003/17 - Rev01
---------------
TITLE:
------
--------------------------------------------------------------------------------
BIOX(R) PILOT RUN ON A BULK CONCENTRATE SAMPLE FROM
THE LA VICTORIA PIT
--------------------------------------------------------------------------------
ACCEPTED:
---------
Name: ...............................................
Signed:..............................................
Order No. ..........................................
For (Customer): ....................................
Date: ..............................................
FIGURE 1: SCHEDULE OF BIOX(R) PILOT TEST PROGRAM
SCHEDULE 2
----------
LICENCE FEE STRUCTURE
LICENCE FEE STRUCTURE
---------------------
1. A licence fee equal to $ 200 000 (two hundred thousand dollars) payable
in installments as follows:
1.1 40% (forty per centum) of the licence fee upon decision by
Crystallex to proceed with the project
1.2 30% (thirty per centum) of the licence fee on date of
commencement of operations
1.3 30% (thirty per centum) of the licence fee on completion of the
performance run.
2. The royalty based on ounces produced from La Victoria to be paid
quarterly based on the following rate of payment:
2.1 Total production up to 300 000 ounces - $ 1,50/oz
2.2 Total production 300 000 - 600 000 ounces - $ 1,25/oz
2.3 Total production 600 000 - 1 000 000 ounces - $ 1,00/oz
2.4 Total production above 1 000 000 ounces - $ 0,85/oz
This royalty payment will be capped at a total production of 1 250 000
ounces.
