FALCON SB

Sepro Mineral Systems History

1986

Falcon Concentrators LTD

Founded in Canada by today’s director Steve McAlister

World leaders in the design and supply of Centrifugal Gravity Concentrators

1987

Sepro Mineral Processing International

Founded in the UK by a dedicated team of engineers led by founder Mike Burton

Developed tyre driven mineral processing equipment: Scrubbers, Agglommerators, Mills

2008

Sepro Mineral Systems

Created through the purchase of Sepro MPI by Falcon Concentrators

Numerous installations world wide

Offices in Canada, UK, Ghana, Austria

World wide representative network

Sepro Equipment Lines

Falcon Semi-Batch Concentrators

Falcon Continuous Concentrators

Falcon Ultra-Fine Concentrators

Sepro Scrubbers

Sepro Grinding Mills

Sepro Agglomeration Drums

Sepro Dense Medium Separators

Sepro Crushers

Sepro-Sizetec Screens

Sepro Leach Reactors

Sepro Pumps

Sepro Mobile / Modular Plants

Falcon SB Introduction

Periodically discharges a high grade concentrate

Centrifugal fields up to 200G’s

Single unit capacities from 1-400t/h

Typical concentrate yield of <0.01%

Typical concentrate grade: +1000 gAu/t

VFD and Dynamic Brake to reduce offline time

Recovery and upgrade down to ~20 microns

Mostly used within grinding circuits (cyclone feed or U/F)

Falcon SB – Applications

Recovery of gold from cyclone feed, underflow or overflow within the grinding circuit

Recovery of gold in alluvial gold operations

Recovery of gold from aggregate plants

Recovery of precious metals in recycling

Falcon SB – How it Works

Water manifold

SFC Water Manifold + AutoPAC

Sepro Flow Control (Fully Automatic)

Strainer (Filter)

Rinse + Flush Solenoid Valves

Flowmeter + Flow Control Valve

MFC Water Manifold + VFD

Manual Flow Control

Strainer (Filter)

Rinse + Flush Hand Valves

Flow Control Hand Valve

Processing cycles

Fluidization water spray Concentrating cycle Rinse cycle

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Test Work

L40 Low Mass Yield (LMY) test with SB bowl

GRG test – The industry standard: 3-pass LMY test with intermediate grind

Mathematical modelling of potential gravity recovery based on the bahaviour of gold in a grinding circuit:

Gold grinds 6 to 20 times slower than gangue

Gold reports to Cyclone U/F at a smaller particle size than gangue due to high SG

GRG (Gravity Recoverable Gold) may turn into NON-GRG by over-grinding and smearing

Increased Recovery: Flotation

Gravity circuit reduces overgrinding and the amount of coarse gold reporting to flotation

Recovery of GRG by flotation is lower at the fine and coarse end of particle sizes

Overall gold recovery increase potential of 1-10%

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Increased Recovery: Leach

Gravity circuit reduces overgrinding and the amount of coarse gold reporting to leach

Finer distribution of gold reporting to conventional leach circuit = faster leaching / shorter leach retention

Reduced carbon stripping effort

Intensive leach for gravity concentrates

Overall gold recovery increase potential of 1-3%

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Metallurgical considerations

Most important parameters for gravity circuit gold production (LaPlante):

1. Centrifuge Throughput in relation to plant throughput (Percentage of circulating load treated)2. Cyclone Efficiency3. Centrifuge Availability4. Centrifuge Stage Recovery (G-Force) (Fluidization) (Cycle time)

PERCENTAGE OF CIRCULATING LOAD TREATED

POTENTIAL BENEFIT

(%) (%)

0 0

10 48

25 70

50 88

75 95

100 100

FLUIDIZATION WATER

G FORCE

60 100 140 180

14 psi

2.274 kg34.9% Rec

2.882 kg35.0% Rec

3.032 kg77.3% Rec

4.525 kg66.3% Rec

20 psi

2.115 kg31.9% Rec

2.611 kg32.6% Rec

2.868 kg46.4% Rec

3.712 kg65.4% Rec

26 psi

1.781 kg31.0% Rec

2.201 kg32.6% Rec

2.747 kg40.1% Rec

3.487 kg70.4% Rec

Placement considerations

Gold grade

Liberation

Pulp density

OPEX

CAPEX

SB

SB

SB

Location of the gravity concentrator

-

Cyclone Underflow Mill discharge / Cyclone Feed Cyclone Overflow

+ Multiple pass environment (Circulating load)Generally 25% or 100% treated

+ Multiple pass environment (Circulating load)Generally 25% or 100% treated

- Single pass environment(Open circuit)Generally 100% treated

+ High gold grade (Circulating load)

+ High gold grade (Circulating load)

- Lower gold grade (Open circuit)

- Potentially low liberation + Increased liberation + Maximum liberation

- Coarser FeedHigh wear

o Finer feed than Cyclone U/F Reduced wear

+ Fine FeedLow wear

- Suboptimum feed pulp density for screening (+60%-wt. solids)

+ Suitable feed pulp density for screening (45-60%-wt. solids)

+ Protection screening not urgently necessary

- Fines by-pass - Fines by-pass (Mill discharge)

+ Treatment of fines (Cyclone O/F)

- Higher structural elevation of mill building

+ Lower structural elevation + Lower structural elevation

o Increased head for cyclone feed pumpNo additional pumps required

- Additional pumps normallyrequired

- Additional pumps may be required

15

Feed Scalping Screen

Scalping at 2mm (slotted screen panel) is today’s standard

Scalping at 1mm screen aperture requires more screen area

Additional effort is often offset by reduced wear on the BCC

Finer screening has metallurgical advantages especially for recovering fine gold (- 53 micron)

VSMA guidelines recommend dilution of both cyclone feed and cyclone U/F for optimum screening. Less dilution required when screening cyclone feed

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Bypass

Bypass during rinse cycle: approx. 2 min

Gold trap in feed line rather than by-bass line

Pinch Valve or Knife Gate Valve

OSHA Office of Training & Education 17

Published fluidization water consumptions: Falcon SB5200: 25 - 35 m3/hKnelson KC-XD48: 28 - 86 m3/hAnnual difference: 200,000 m3 (8000 h/a)

Affects water balance around grinding mill

Affects operating costs, downstream capital costs

High quality, clean water required, typical specification: < 100 ppm solids< 5 micron

Poor water quality affects maintenance and downtime

Typical minimum supply pressure: 40-50 psi

OSHA Office of Training & Education 18

Rotor comparison

ImpellerStratification zone: Acceleration and stratificationRetention zoneOptimum fluidization water utilization at most effective point

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Availability – Zoned approach

Mechanical availability of gravity circuit is second largest determinant of gravity gold production.

Zoned approach: ImpellerLower strike point Lip ring

Major wear parts are not recovery related

Wear items are separate exchangeable parts

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Concentrate Handling Options

Blend gravity concentrate with Flotation concentrate

Sell gravity concentrate separately

Shaking table (to Smelting)

Intensive Leach (to Electrowinning/Smelting)

Caso Práctico

OSHA Office of Training & Education 21

Recuperación diaria por Gravimetría

OSHA Office of Training & Education 22

Recuperación mensual

OSHA Office of Training & Education 23

Prueba GRG

OSHA Office of Training & Education 24

OSHA Office of Training & Education 25

Gravity Devices

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Sepro Mineral Systems

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