® CONSULMET

1

Lwazi Mthwana

11th DMS Symposium

February 2014

Abstract

Who is Consulmet

Introduction

Test-work

Design Criteria

Plant Flow Description

Commissioning Experiences

Conclusion

Discussion

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Gecamines Kamfundwa Copper Beneficiation plant was commissioned between September and November 2013

This paper discusses the basic principles of DMS commissioning in a copper application

Overview of initial test-work and design criteria

Challenges that were experienced

Discussion focuses on the following items: ◦ Pressure Control

◦ Effect of Medium Density on Cyclone Performance (cut point, yield and grade)

◦ Power and water supply

◦ FeSi Losses

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Consulmet (Pty) Limited specialises in the application of modular recovery solutions for the mining sector of the minerals industries, predominantly on the African continent.

Consulmet provides a fully comprehensive service comprising of the design, construction, commissioning and trouble-shooting of mineral processing plants

Design offices in Johannesburg and Cape Town

Fabrication workshop in Klerksdorp

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Kamfundwa Plant is located in Kambove in the Democratic Republic of Congo

300 tph Head Feed, 150 tph DMS

Produce 15% concentrate from 2% copper in malachite-rich ore

The concentrate would be further

processed in Gecamines existing

facilities

5

Particle Size Distribution for sizing equipment

Densimetric analysis to determine whether DMS was a suitable method of separation

Assaying to determine copper grade of feed material, expected grade of concentrate and tailings

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DMS was a suitable method of separation

The optimum recovery occurs at a cut point density of 2.72t/m3

7

Equipment sizing completed using PSD from test work

Compact plant with minimal conveyors

Pump fed DMS that allowed for a compact design and hence less steel work

VSD on cyclone feed pump for pressure control

Use of basic, proven technology and standard designs that have been proven to work

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9

Mineralogy

Value (%)

Copper content in ROM 2 – 2,5

Malachite 85

Pseudomalachite& Chrisocolla 10- 15

Heterogenite 0,8 – 2

Impurities Non magnetic

Operating Schedule

Value

Operating hours per day 20

Number of operating days per year 360

Total operating hours per year 7200

Availability of plant (%) 82

DMS Circuit

Value Units

Feed surge bin capacity 115 Tons Total

Total DMS feed as % of ROM 50 – 60 %

DMS feed rate 150 tph

Feed prep screen cut size 1 mm

Cyclone size 510 mm

Number of cyclones in module 2

Nominal medium : ore ratio 6: 1

Cyclone cut point density 2.72 t/m3

Cyclone operating head 15 D

Design yield to sinks 9 – 12.5 %

GRIZZLY JAW

CRUSHER

SCRUBBER SIZING SCREEN

CONE CRUSHER

DMS

SPIRALS

PRODUCT

Plant Feed

-1mm Effluent

-100mm

+100mm

+19mm

-19+1mm

-1mm

Tailings

Slimes

10

11

12

PI

PI

SINKS -19 +1mm

150 TPH

-19 +1mm

201-CHU-001

DMS FEED (-19 +1MM)

FROM 101-CVR-010

A100-PFD-101

201-SCR-001

201-UPN-001

201-MXB-001

201-PMP-001

201-CYC-001 A

2

4

3

5 201-CYC-001 B

201-SCR-002

201-SCR-003

201-SCR-004

201-UPN-002

10 21

201-CHU-002

7

8

201-SMP-001

201-SMP-002

201-PMP-002 201-PMP-003

201-PMP-004

201-PMP-006

201-MAG-001

201-DMG-001

201-SMP-003

201-PMP-005

201-SMP-004

201-DMC-001

M

M

M

MM

M

M

M

M

PROCESS WATER

FROM A101

A100-PFD-101

25

22

15

17

16

26

DMS SINKS TO

101-CVR-007 (-19+1mm)

A100-PFD-10123

201-SCR-005

6

M

FLOATS -19 +1mm

201-CHU-003

DMS FLOATS TO

101-CVR-008 (-19+1mm)

A100-PFD-101

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PI

13 14

12

9

2019

18

DMS EFFLUENT

201-UPN-003

201-SPL-001 201-SPL-002

201-DST-001

201-DNS-001 B

201-DNS-001 C

201-DNS-001 A

201-DST-002

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R/LINED

R/LINED

R/LINED

R/LINED

R/LINED R/LINED

R/LINED

R/LINED

CERAMIC

LINED

R/LINED

GLAND

WATER

FIELD MOUNTED

CONTROL PANEL

160MM ORIFICE C/W

REPLACEABLE

145, 150 &155MM

ORIFICE PLATES

PI PI

PI

VSD

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28

FLOOD

BOX

CRAWL BEAM

CYCLONE FEED PUMP

MAINTENANCE

201-HST-002

BOX

MAGNET

CRAWL BEAM CIRC.

MEDIUM PUMP

MAINTENANCE

201-HST-003

COMPRESSOR

201-CMP-001

MOTOR CONTROL

CENTRE (MCC)

(A201)

1

29

FR

ON

T E

ND

DM

S

FRONT END

DMS

FRONT END

DMS

FRONT END

DMS

FRONT END

DMS

NOTE 5

PT

®CONSULMET

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Cyclone Pressure ◦ VSD driven cyclone feed pump

◦ Speed of VSD was adjusted to maintain the mixing box level (78% to 90% VSD speed)

◦ Pump operated at a range of 12.5D to 14D

◦ Pressure on both cyclones were the same during operation

◦ No fluctuation of pressure during normal operation

◦ No significant changes noted in the efficiency of the separation as a result of change in cyclone pressure

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Density ◦ Initial start of plant was with a correct medium of specific gravity

2.65

◦ Tracer Test showed a cut point of 3.01 t/m3 and a yield of 6.7%, producing a product of 45% grade

◦ The grade was high and yield was low

◦ Medium density was dropped incrementally. The results showed a drop in cut point and an increase in yield

Medium Density Cut Point (t/m3) Yield (%)

2.65 3.01 6.7

2.6 2.96 8.1

2.55 2.87 9.4

2.5 2.83 10.2

2.45 2.78 11.1

2.4 2.68 12.3

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Initial Set Up

Medium SG 2.65

Cut Point 3.01 t/m3

Yield 6.7 %

Product Tons 10.0 tph

Grade 45 %

Final Set Up

Medium SG 2.40

Cut Point 2.68 t/m3

Yield 12.3 %

Product Tons 18.5 tph

Grade 31 %

Density

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Density Control and Densification ◦ Float screen spray water splashed into drain side of underpan,

causing dilution of correct media

◦ Rate of densification increased by using two densifiers. One densifier was always on standby

Drain side to correct medium sump

Wash side To dilute medium sump

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Process Water Supply ◦ Process water supply pump was powered by local power

◦ Low power availability. Loss of power occurred 2 to 3 times a day for a period of no less than hour

◦ Every time there was a power failure, the plant had to be stopped and the DMS had to be flushed and brought to a gentle stop

◦ Alertness at DMS was needed since time was a factor. Level of process water dam was closely monitored

◦ Frequency of start-stop provided good training for DMS operators

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FeSi Consumption ◦ Start-stop of DMS lead to high FeSi consumption as FeSi was

lost during flushing of pipelines and pumps.

◦ FeSi was lost when washing FeSi from the floor back into the circuit

◦ Compressed air was used keep FeSi in suspension in the CM sump while plant was idling. CM sump had to flushed after 12 hours of idling to prevent choke-up

◦ No significant FeSi losses were caused by the magnetic separator

◦ High pressure on sinks and float screens spray water assisted with FeSi recovery

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DMS Start-Up ◦ Initially, the DMS took over 1 hour to start-up. The time was

used to attain the set point density in the correct media

◦ Upon shut-down, it became an adopted operating philosophy to wash in the drained FeSi back into the correct medium sump

◦ This assisted in reducing start-up time to less than an hour

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Test work showed that no significant increase in grade (30%) occurred at a cut point density above 2.7 t/m3. In practise, the grade at a cut point of 3.01 t/m3 was 45%

By dropping the cut point density from 3.01 t/m3 to 2.68 t/m3, the yield was increased by 84%

A lower density increases utilisation of the plant. Decrease in downtime is due to steadier control of density

Multiple hoses for washing in FeSi assist in reducing DMS start-up time

VSD driven cyclone feed pump and 2-way Y piece distributor provides efficient pressure control

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The DMS process can be effectively used to upgrade the concentration of copper from malachite-rich ore

Product contained 31% copper, and discard contained 0.5% copper

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31% Copper 0.5% Copper

The commissioning of Kamfundwa Copper Beneficiation Plant was a success, with no major problems as a result of the design, construction or operation

The success can largely be attributed to the use of proven technology and designs

The application of basic principles and technology can still be the key factor to a successful project

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