CONSULMET. Lwazi Mthwana 11 th DMS Symposium February 2014

Transcription

1 CONSULMET Lwazi Mthwana 11 th DMS Symposium February

2 2 Abstract Who is Consulmet Introduction Test-work Design Criteria Plant Flow Description Commissioning Experiences Conclusion Discussion

3 3 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

4 4 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

5 5 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

6 6 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

7 7 DMS was a suitable method of separation The optimum recovery occurs at a cut point density of 2.72t/m 3

8 8 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

9 9 Mineralogy Value (%) Copper content in ROM 2 2,5 Malachite 85 Pseudomalachite& Chrisocolla 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 % 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/m 3 Cyclone operating head 15 D Design yield to sinks %

10 10 Plant Feed Slimes GRIZZLY +100mm JAW CRUSHER -1mm SPIRALS -100mm PRODUCT SCRUBBER SIZING SCREEN -19+1mm DMS Tailings +19mm -1mm Effluent CONE CRUSHER

11 11

12 12 PROCESS WATER FROM A101 A100-PFD-101 DMS FRONT END 25 PI 29 DMS FEED (-19 +1MM) FROM 101-CVR-010 A100-PFD TPH mm CHU-001 FRONT END 2 DMS 201-SCR-001 M 4 R/LINED 201-UPN MXB-001 R/LINED 201-CYC-001 A M COMPRESSOR 201-CMP MM ORIFICE C/W REPLACEABLE 145, 150 &155MM ORIFICE PLATES GLAND WATER PI VSD PT M CYC-001 B 201-PMP DST-002 CERAMIC PI 7 LINED SCR SCR-005 M DMG MAG HST-002 R/LINED FIELD MOUNTED CONTROL PANEL CRAWL BEAM CYCLONE FEED PUMP MAINTENANCE 201-SCR-002 BOX MAGNET M 201-SCR UPN-003 FLOOD BOX 201-CHU MOTOR CONTROL CENTRE (MCC) (A201) UPN-002 R/LINED FRONT END 201-CHU-002 DMS FRONT END FLOATS mm SINKS mm 23 DMS FLOATS TO 101-CVR-008 (-19+1mm) A100-PFD-101 DMS SINKS TO 101-CVR-007 (-19+1mm) A100-PFD-101 DMS 201-DNS-001 A DNS-001 B 22 PI 201-DNS-001 C PI PI DST R/LINED 201-SPL R/LINED 201-SPL DMC-001 R/LINED 201-SMP-002 R/LINED 201-SMP-001 M M M 201-PMP SMP-003 R/LINED 201-PMP PMP-003 M FRONT END 26 DMS EFFLUENT CRAWL BEAM CIRC. MEDIUM PUMP MAINTENANCE 201-PMP-005 DMS NOTE HST SMP-004 M 201-PMP-006 CONSULMET

13 13

14 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 14

15 15 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/m 3 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/m 3 ) Yield (%)

16 16 Density Initial Set Up Final Set Up Medium SG 2.65 Cut Point 3.01 t/m 3 Yield 6.7 % Product Tons 10.0 tph Grade 45 % Medium SG 2.40 Cut Point 2.68 t/m 3 Yield 12.3 % Product Tons 18.5 tph Grade 31 %

17 17 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

18 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 18

19 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 19

20 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 20

21 21 Test work showed that no significant increase in grade (30%) occurred at a cut point density above 2.7 t/m 3. In practise, the grade at a cut point of 3.01 t/m 3 was 45% By dropping the cut point density from 3.01 t/m 3 to 2.68 t/m 3, 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

22 22 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 31% Copper 0.5% Copper

23 23 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

24 24