Centralized Milling of Newfoundland Base Metal Deposits ... · potential, compliance with market...

Centralized Milling of Newfoundland Base Metal Deposits

Process Flowsheet DevelopmentNewfoundland and Labrador Mineral Resources Review 2017

© Copyright 2017 Thibault & Associates Inc. All rights reserved. REV 00 November 02, 2017

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Forward‐looking StatementsAlthough the forward‐looking statements contained in this Presentation are based upon whatmanagement and professionals believe to be reasonable assumptions, Thibault & Associates Inc. cannotassure that actual results will be consistent with these forward‐looking statements. These forward‐looking statements are made as of the date of this Presentation, and Thibault & Associates Inc. assumesno obligations to update or revise them to reflect new events or circumstances.

Certain statements in this Presentation may constitute “forward‐looking” statements which involveknown and unknown risks, uncertainties and other factors which may cause the actual results,performance or achievements of Thibault & Associates Inc., or the industry in which it operates, to bematerially different from any future results, performance or achievements expressed or implied by suchforward looking statements.

New risk factors may arise from time to time and it is not possible for management and professionals ofThibault & Associates Inc. to predict all of those risk factors or the extent to which any factor orcombination of factors may cause actual results, performance or achievements of Thibault & AssociatesInc. to be materially different from those contained in forward‐looking statements. Given these risks anduncertainties, the reader should not place undue reliance on forward‐looking statements as a predictionof actual results.

This document is of exclusive rights of Thibault & Associates Inc. ©2017No use, copy, change or disclosure is permitted without written consent.

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Project Objectives

Conceptual study to assess the technical and economic viability of a Centralized Concentrator for the production of copper, lead and zinc concentrates from multiple base metal deposits.

Assess amenability of pre‐concentration using Dense Media Separation (DMS) to reduce mining or transport costs to central mill.

Define a common flotation flowsheetand reagent scheme for processing all deposits.

Mine plan, process simulation and a relative conceptual economic evaluationto compare various centralized milling production scenarios.

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Project Management

Collaborative study.

Canadian Zinc Corporation (CZN) Buchans Resources Limited (BRL)

Lundberg (2 samples)

Boomerang

Lemarchant Massive Sulfide (MS)

Lemarchant Footwall (FW)

Daniels Pond

Bobbys Pond

In central Newfoundland, CZN and BRL collectively have Indicated and Inferred Resources at 28.9 million tonnes at 2.2% Zn, 0.81% Pb, 0.40% Cu (NI 43‐101 Compliant). [approximately 0.5 million tonnes of recoverable zinc].

Study completed March 27, 2017 (16 month study). Co‐funding by CZN, BRL and RDC.

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Speciality ‐ Resource Based Production Strategies

Thibault & Associates Inc. has provided process engineering and project management services to the resource based industries since 1987 / 1988 (30 years).

In‐house capabilities for process development (bench scale and pilot facilities) and process design services.

Independent technical ‐ economic assessment of production strategies ‐ based on AACE and NI 43‐101 guidelines.

Plant design, equipment procurement, construction documentation, coordination of multi‐discipline plant design and in‐plant optimization (process intensification studies / after‐care).

Antimony Trioxide Indium Tin Oxide

Electrolytic Zinc Plates

Technical and Economic Viability of Technology

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Define process technology based on earning potential, compliance with market specifications and environmental protocol.

Identify “innovative solutions” to support business plans and development of test programs to quantify technical parameters.

Preparation of an economic model that define earning power relative to technical and economic parameters.

Integrated plant design and economic studiesbased on process chemistry, equipment selection, plant layout, process control, construction and operating practices.

Process Simulation and Economic Evaluation Models

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Use of process simulation models to assess production strategies, technical demands and constraints that occur during the life span of the project.

Economic modelling provides a logical template to help organize resource development strategies and defines the relative impact of production technology on earning potential.

Our dynamic models are fully integrated process simulation and economic models.How is the product made and what is the production cost?

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Process Simulation – Mass and Energy Balance

ProSEETMProcess Simulation Economic Evaluation

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Revised Flowsheet / Product Opportunity

Flowsheet Design

Ore Delination

Mass and Energy Balance Simulation

Mine Plan Design

Ore Grade and Tonnage

Equipment Sizing / Cost Estimation

CAPEX / OPEX Cash Flow Model

Revenue Generator

Economic Viability

Process Definition

Return on Investment

Project Life

Simulation of process chemistry

Process mass and energy balance

Equipment sizing / energy loads

Capital cost estimates (CAPEX)

Operating cost estimates (OPEX)

Cash flow – sensitivity assessment

“Loaded model” includes:

resource / feedstock definition; revenue generation; mining, processing costs; infrastructure and administrative costs; owners costs; sustaining capital, taxation, depreciation and; risk assessment .

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Immediate Challenges ‐ Zinc

Zinc is defined as the primary economic driver for base metal feedstocks (run‐of‐mine ore).

Approximately 50% of base metal revenue is from zinc concentrates and zinc has a relatively low NSR.

Projected zinc supply deficit – gap for zinc demand and supply for 2020 is significant.

Increased demand for smelting lower grade dirty zinc concentrates .

Sulfuric acid co‐production and marketing –competing with sulfur pricing.

High smelter production cost ‐ higher energy costs, higher transportation costs and higher unplanned maintenance outage.

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Base Metal Resource Development Directives

Zinc global demand around 14.0 million tonnes annually (2016) with galvanizing 50% and zinc alloying around 17% of demand.

Alternatives to zinc metal production include zinc chemicals with zinc oxide global demand around 1.3 million tonnes annually (Technavio, 2016).

Search for “profitable overall production strategies” from mine to metal. No single mine can supply global zinc demand.

Economy of scale for zinc metal supply chain as an alternative to smelter production.

Ability to process lower grade run‐of‐mine ore with fine grain mineralization and high impurity content (As, Cd, Se, Hg, etc.).

Demonstrate fully integrated process viability based on product purity and recovery.

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Base Metal Potential for Central Newfoundland

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Centralized Base Metal – Fully Integrated Model

Centralized processing of ores from satellite deposits. Satellite deposits with low tonnage do not support processing at the mine site.

Centralized processing concepts under review in Canada include Northwest Territories, Manitoba, Quebec, New Brunswick and Newfoundland.

Process technological development for base metal / primary massive sulfide deposits in the Iberian Pyrite Belt (IPB) located in Portugal and Spain (reserves containing up to 50 million tonnes of recoverable zinc metal).

Project economics are dependent on “flotation process technology”.

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Resource Location

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Canadian Zinc and Buchans Resource (2016)

Canadian Zinc Resources:

High grade, low tonnage

Potential underground

No economic studies to date

Buchans Resources:

Lundberg open pit potential, 2011 stand‐alone PEA study

Bobbys and Daniels:o High grade, low tonnageo Potential undergroundo No economic studies to date

Deposit NI 43‐101 Category Tonnes Zn (%) Pb (%) Cu (%)

BoomerangIndicated 1,364,600 7.07 3.00 0.51Inferred 278,100 6.72 2.88 0.44

Domino Inferred 411,200 6.30 2.80 0.40

LemarchantIndicated 1,240,000 5.38 1.19 0.58Inferred 1,340,000 3.70 0.86 0.41

Deposit NI 43‐101 Category Tonnes Zn (%) Pb (%) Cu (%)

LundbergIndicated 23,440,000 1.41 0.60 0.35Inferred 4,310,000 1.29 0.54 0.27

Bobbys PondIndicated 1,095,000 4.61 0.44 0.86Inferred 1,177,000 3.75 0.27 0.95

Daniels PondIndicated 1,160,000 4.44 2.12 0.31Inferred 450,000 3.88 1.74 0.27

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Sample Characterization – Head Grades

Sample Pb/Cu Ratio

Assays

Cu (%) Pb (%) Zn (%) Au (g/t) Ag (g/t) As (%) S (%)

Boomerang 4.7 0.62 2.91 7.51 1.46 113 0.74 31.7

Lemarchant MS 2.2 1.51 3.29 10.91 5.73 198 0.12 17.1

Lemarchant FW 0.2 0.34 0.07 2.36 0.09 3.8 0.005 3.4

Daniels Pond 8.8 0.35 3.07 6.68 0.66 94 0.38 20.7

Bobbys Pond 0.6 0.95 0.55 6.43 0.21 22 0.053 16.0

Lundberg Y1‐3 1.8 0.56 1.02 2.14 0.05 6 0.006 9.9

Lundberg Y4‐8 2.0 0.35 0.71 1.47 0.07 6 0.005 9.5

Footwall (FW) and Massive Sulphide‐Barite (MS) tested separately for Lemarchant

Lundberg Years 1‐3 and Years 4‐8 tested separately – same samples as collected for 2013 prefeasibility test work.

Bench Scale Flotation Test Samples

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Sample Characterization – Mineralogy

SampleGangue Grain Size Secondary

CuAs/Sb with

CuSulphide Barite Silicate Coarser Med. Finer

Boomerang X X Minor X

Lemarchant MS X X X Major X

Daniels Pond X X X Major X

Bobbys Pond X X X Minor

Lundberg X X

Bobbys Pond and Lundberg: most straightforward mineralogy for flotation

Secondary copper (bornite, covellite, chalcocite, tetrahedrite, tennantite) can be slightly soluble in water – copper ions cause zinc to float with copper concentrate

Tetrahedrite/tennantite (As and Sb bearing Cu minerals) float with the copper concentrate – potential As/Sb penalties

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Sample Characterization – Mineralogy

60.0

65.0

70.0

75.0

80.0

85.0

90.0

95.0

100.0

0 10 20 30 40 50 60 70

Percen

t Liberated

Mineral (>

80%)

Particle 80% Passing Size (microns)

Bobbys Pond

Sphalerite

Copper Sulphides

60.0

65.0

70.0

75.0

80.0

85.0

90.0

95.0

100.0

10 20 30 40 50 60

Percen

t Liberated

Mineral (>

80%)

Particle 80% Passing Size (microns)

Boomerang

Sphalerite

Copper Sulphides

Use of mineralogy to identify target grind to liberate minerals for flotation

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Centralized Processing Overview – Pre‐concentration

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Pre‐concentration by Dense Media Separation

Not all ores are amenable to upgrading by dense media separation – grade, recovery and mass rejection defined by bench scale tests.

Principles of upgrading are based on specific gravity of base metal mineralization relative to gangue mineralization and control of the media specific gravity.

Fines are removed from crusher ore and fine particles of ferrosilicon (dense media) are used to alter the specific gravity of the slurry.

DMS operations in the mine are used to upgrade ore and reduce the amount of ore transported to the surface or to a centralized processing facility.

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Bench Scale Dense Media Separation

DMS used for pre‐concentration ahead of typical grinding and flotation process

Density‐based separation for base metals:

o Light waste mineralso Heavy valuable minerals

Ore mineralogy must allow crushing to liberate light and heavy minerals

DMS best suited to stringer sulphide deposits

Massive sulphide deposits difficult to upgrade by DMS

15 samples tested

Separation specific gravity: 2.70 to 3.30

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Bench Scale Dense Media Separation ‐ Copper

90%

91%

92%

93%

94%

95%

96%

97%

98%

99%

100%

60% 65% 70% 75% 80% 85% 90% 95% 100%

Cop

per R

ecov

ery

to S

inks

+ F

ines

(%)

Weight Recovery to Sinks + Fines (%)

Lundberg Tomra Sorting Lundberg Y1-3

Lundberg Y4-8 Lemarchant FW

Bobbys Pond Comp Bobbys Pond 06-16

Daniels Pond Comp Long Lake SMSB

Domino SMS Tullks Hill MS

Tulks East MS Boomerang MS West

Boomerang MS Core Boomerang Au Rich

Lemarchant MSB

Stringer or Semi‐massive sulphide (best)

Massive sulphide(less separation)

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Bench Scale Dense Media Separation ‐ Lead

90%

91%

92%

93%

94%

95%

96%

97%

98%

99%

100%

60% 65% 70% 75% 80% 85% 90% 95% 100%

Lead

Rec

over

y to

Sin

ks +

Fin

es (%

)


Lundberg Tomra Sorting Lundberg Y1-3

Lundberg Y4-8 Lemarchant FW

Bobbys Pond Comp Bobbys Pond 06-16

Daniels Pond Comp Long Lake SMSB

Domino SMS Tullks Hill MS

Tulks East MS Boomerang MS West

Boomerang MS Core Boomerang Au Rich

Lemarchant MSB



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Bench Scale Dense Media Separation ‐ Zinc

90%

91%

92%

93%

94%

95%

96%

97%

98%

99%

100%

50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%

Zinc

Rec

over

y to

Sin

ks +

Fin

es (%

)


Lundberg Tomra Sorting Lundberg Y1-3Lundberg Y4-8 Lemarchant FWBobbys Pond Comp Bobbys Pond 06-16Daniels Pond Comp Long Lake SMSBDomino SMS Tullks Hill MSTulks East MS Boomerang MS WestBoomerang MS Core Boomerang Au RichLemarchant MSB



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Bench Scale Dense Media Separation ‐ Recoveries

Sample Overall Metal Recovery to Sinks + FinesCu (%) Pb (%) Zn (%) Au (%) Ag (%)

Lemarchant FW 94.6 97.7 95.4 97.4 96.4

Bobbys Pond SMS Comp 98.3 98.6 99.1 95.6 95.6

Bobbys Pond SMS 06‐16M 94.8 92.1 93.3 92.5 97.8

Daniels Pond SMS Comp 91.7 96.3 96.0 84.4 94.3

Domino SMS 91.4 93.7 95.3 91.1 92.6

Lundberg Y1‐3 98.3 96.6 96.5 89.6 95.3

Lundberg Y4‐8 94.7 94.2 93.9 84.8 90.1

Metal recoveries with 30% rejection of waste material

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Centralized Processing Overview ‐ Flotation

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Bench Scale Flotation Flowsheet Development

Boomerang Cu, Pb, Zn concentrates

Lemarchant MS Cu, Pb, Zn concentrates

Common challenges in previous test work:

Inefficient separation between Cu, Pb, Zn

Zn contamination of Cu, Pb concentrates

Low Zn recoveries

Low grade Cu concentrates

Current study focussed on better separation of Cu, Pb and Zn by:

Alternative flowsheets

More selective reagent schemes

Finer grinds to improve liberation

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Bench Scale Flotation Flowsheet Selection

Bulk Cu/Pb Flowsheet:

Cu and Pb floated together

Bulk con. then cleaned and Cu/Pbare separated

Zn float same as sequential

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Bench Scale Flotation Flowsheet Selection

Sequential Flowsheet:

Fine grind to liberate Cu, Pb, Zn minerals

Cu, Pb, Zn floated in order of natural floatability

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Bulk Cu/Pb vs. Sequential Flowsheet

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

Cu Pb Zn Fe

Gra

de (w

t%)

Bulk Sequential

Boomerang Final Copper Concentrate Grades

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Bulk Cu/Pb vs. Sequential FlowsheetBoomerang Grade‐Recovery Relationships

0

20

40

60

80

100

0 10 20 30 40 50 60 70

Rec

over

y (w

t%)

Grade (wt%)

Copper Sequential

Lead Sequential

Zinc Sequential

Copper Bulk

Lead Bulk

Zinc Bulk

Cu

PbZn

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Sequential Flowsheet Test Program Sequential flowsheet selected based on better flotation selectivity

More detailed tests for selection of grind size, regrind size, reagent dose and operating conditions to improve performance

Outcome: Each deposit responds well to the sequential flowsheet and the same reagent scheme, with reagent dose adjustments

Test program included 166 batch open circuit flotation tests on 7 samples

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Sequential Flowsheet Copper Concentrate GradesOpen Circuit Bench Test Results

Sample Cu (%) Pb (%) Zn (%) Ag (g/t) Au (g/t) As (%) Sb (%)

Boomerang 27.38 5.65 1.46 1318 7.65 0.28 0.56

Lemarchant MS 34.59 1.29 4.74 1578 15.46 3.14 0.89

Lemarchant FW 31.00 0.61 1.11 112 1.63 0.02 0.006

Daniels Pond 18.82 26.75 8.08 1487 8.15 0.76 0.44

Bobbys Pond 30.92 1.90 1.44 125 0.58 0.28 0.03

Lundberg Y1‐3 32.06 2.10 1.43 29 0.16 0.007 0.003

Lundberg Y4‐8 30.93 0.85 0.81 19 0.68 0.003 0.002

Cu concentrates improved over previous testing

Daniels Pond most challenging for making a copper concentrate

Good Cu grades other than Daniels Pond

Zn rejection good except for Daniels Pond

Elevated As, Sb in Boomerang, Lemarchant MS and Daniels Pond

Pb elevated for Boomerang, Bobbys Pond, Lundberg and Daniels Pond

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Sequential Flowsheet Lead Concentrate Grades

Good open circuit Pb grades, good Zn rejection

As elevated only in Boomerang

Clean concentrates

Open Circuit Bench Test Results


Boomerang 0.67 63.78 2.93 751 5.16 0.47 0.13

Lemarchant MS 0.21 80.88 3.23 344 344 0.007 0.01

Lemarchant FW ‐ ‐ ‐ ‐ ‐ ‐ ‐

Daniels Pond 1.06 77.51 4.87 599 5.55 0.08 0.05

Bobbys Pond 0.68 80.58 5.14 318 1.68 0.09 0.008

Lundberg Y1‐3 0.31 74.76 3.56 260 0.55 0.05 0.002

Lundberg Y4‐8 0.38 75.93 2.80 263 1.13 0.03 0.003

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Sequential Flowsheet Zinc Concentrate GradesOpen Circuit Bench Test Results


Boomerang 0.17 0.64 55.96 39 0.43 0.23 0.008

Lemarchant MS 0.15 0.57 64.29 35 0.23 0.0004 0.004

Lemarchant FW 0.28 0.91 59.89 19 0.13 0.009 0.002

Daniels Pond 0.14 1.27 67.02 46 0.18 0.03 0.007

Bobbys Pond 0.16 0.27 64.81 18 0.21 0.01 0.02

Lundberg Y1‐3 0.60 0.71 62.52 18 0.11 0.003 0.003

Lundberg Y4‐8 0.98 0.75 60.64 24 0.15 0.001 0.004

Clean, high grade concentrates

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Sequential Flowsheet Copper RecoveriesClosed Circuit METSIM Simulation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Boomerang Lemarchant MS Lemarchant FW Bobbys Pond Daniels Pond Lundberg Y1-3 Lundberg Y4-8

Cop

per R

ecov

ery

(wt%

)

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Sequential Flowsheet Lead RecoveriesClosed Circuit METSIM Simulation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Boomerang Lemarchant MS Bobbys Pond Daniels Pond Lundberg Y1-3 Lundberg Y4-8

Lead

Rec

over

y (w

t%)

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Sequential Flowsheet Zinc RecoveriesClosed Circuit METSIM Simulation

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Zinc

Rec

over

y (w

t%)

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Sequential Flowsheet Gold Overall RecoveriesClosed Circuit METSIM Simulation – Gold Recovered to All Three Concentrates

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Gol

d R

ecov

ery

(wt%

)

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Sequential Flowsheet Silver Overall RecoveriesClosed Circuit METSIM Simulation – Silver Recovered to All Three Concentrates

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Silv

er R

ecov

ery

(wt%

)

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Centralized Processing Overview ‐ Hydromet

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Hydrometallurgical Processing of Concentrates

Use of hydromet to process selective flotation Cu/Pb and Zn concentrates.

Zinc hydromet based on selective leaching of zinc, purification by solvent extraction and electrowinning of zinc metal in a sulfuric acid circuit.

Leaching of copper in a sulfuric acid media such that lead is insoluble and use of solvent extraction purification and copper metal recovery by electrowinning.

Recovery of lead using a chloride hydromet and solution is purified by removal of impurities and lead carbonate is recovered by precipitation.

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Hydrometallurgical Processing of Zinc Concentrates

To improve on the overall economic viability of the project, copper and lead hydromet is eliminated.

Based on the current NSR for both copper and lead concentrates (at the scale of operation) smelting has a higher earning potential relative to a copper and lead hydromet.

Based on the current NSR for zinc concentrates, use of a zinc hydromet has economic potential as an add‐on to a selective flotation process.

The viability of a zinc hydromet is very dependent on impurities in concentrate, transport costs, electrical power costs and economy of scale.

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Centralized “Bulk Concentrate” Hydromet ConceptDevelopment option defined for low metal recovery with selective flotation.

Process based on operating flotation to achieve a lower grade concentrate with a high recovery.

Early process development phase for deposits in Spain and Mexico based on low lead ores.

Economics of hydromet are based on economy of scale. Risk associated with supply of bulk concentrates for life of project at high tonnages.

Ability to treat dirty concentrates. Proven technologies for solution purification using zinc and copper solvent extraction (SX) and impurity removal by ion exchange (IEX).

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Summary

Sequential flotation flowsheet was defined as a technically viable technology, that provides flexibility for the production of copper, lead and zinc concentrates from central Newfoundland satellite deposits – using a common flotation reagent scheme with a specific reagent dose to improve on selectivity for each deposit.

An economic model was developed for the centralized milling – production of concentrates, to assess the earning potential sensitivity to i) pre‐concentration by dense media separation, ii) location of the centralized mill, iii) effect of impurity and impact on net smelter return (unique to each deposit), iv) recovery, v) production tonnage and vi) sequential development / mine plan for each deposit.

Added value production of metal by hydrometallurgical processing of concentratescould improve on the project’s earning potential, however, is dependent on economy of scale. Based on 100,000 tonne of zinc metal production annually and a 25 year project life, a multi‐deposit resource definition should target run‐of‐mine feedstock in the range of 60 to 150 million tonnes (at 2% to 5% Zn and 85% recovery).

330 Alison Blvd.,Fredericton, New BrunswickCanada, E3C 0A9

T: 506.454.2359F: 506.454.2349E: d.thibault@thibault‐process‐engineering.ca

www.thibault‐process‐engineering.ca

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1988 to 2018

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