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THE UNIVERSITY OF ZAMBIA

SCHOOL OF ENGINEERING

DEPARTMENT OF MECHANICAL ENGINNERING

INDUSTRIAL TRAINING REPORT

At: KANSANSHI MINE

Period from: 22/10/2012 to 29/12/2012

Student Name: Chilufya Mubanga B.

Student ID Number: 29031800

Course Code: EG 493

Submitted to: Mr S. S. Virdy

2012/2013

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LIST OF FIGURES

Figure page

Figure 1: Sump pumps, exploded view……………………………………………………………………………….5

Figure 2: High head pump, exploded view………………………………………………………………………….6

Figure 3: AH Elastomer pump exploded view……………………………………………………………………..6

Figure 4: Proposed pipeline from pre-leach tank to leach tank 3……………………………………….8

Figure 5: proposed pipeline from dewatering to leach tank 3 (option 1)……………………………8

Figure 6: Proposed pipeline from dewatering to leach tank 3 (option 2)……………………………8

Figure 7: PP 6022 Pump (C-5 high lift pump)………………………………………………………………………9

Figure 8: high lift pump inlet and outlet diameter……………………………………………………………..9

Figure 9: pump curve…………………………………………………………………………………………………………10

Figure 10: Open belt drive…………………………………………………………………………………………………11

Figure 11: belt type selection chart……………………………………………………………………………………12

Figure 12: Pipe system pressure and pressure drops…………………………………………………………15

Figure 13: project design……………………………………………………………………………………………………16

Figure 14: pressure, temperature and mass flow rate distribution at optimum conditions 18

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CONTENTS

1. ACKNOWLEDGEMENT …………………………………………………………………………………………………………………4

2. SUMMARY……………………………………………………………………………………………………………………………………4

3. INTRODUCTION……………………………………………………………………………………………………………………………4

4. COMPANY PROFILE……………………………………………………………………………………………………………………...4

5. MACHINERY…………………………………………………………………………………………………………………………………5

5.1 Centrifugal Pumps……………………………………………………………………………………………………………………….5

5.1.1 Sump Pumps…………………………………………………………………………………………………………...............5

5.1.2. High Head Pump…………………………………………………………………………………………………………………6

5.1.3. AH Elastomer Pump……………………………………………………………………………………………………………6

6. MAIN ACTIVITIES………………………………………………………………………………………………………………………….7

6.1. Propose pipelines to leach tank 3 from dewatering tank and pre-leach tank……………….……….7

6.1.1 Dewatering tank…………………………………………………………………………………………………………...7

6.1.2 Pre-leach Tank……………………………………………………………………………………………………………..7

6.1.3 Scope of Work………………………………………………………………………………………………………………7

6.2. C-5 High Lift Pump (pp6022) Motor and Drive System upgrade…………………………………………….9

6.2.1 Scope of Work…………………………………………………………………………………………………………….9

6.2.2 Power calculation…………………………………………………………………………………………………….9

6.2.3. Drive system…………………………………………………………………………………………………………….11

6.2.3.1 Selection- wedge belt drives………………………………………………………………………..11

6.2.3.2 Head loss calculations………………………………………………………………………………….14

6.3. Solvent extraction plant 3 (SX3) organic inter-stage bypass pipeline…………………………….16

6.4 Plant Sump pump Catalogue ………………………………………………………………………………………….17

6.5 AP5 Steam Turbine Research Project………………………………………………………………………………17

6.5.1 Scope of Work …………………………………………………………………………………………………..17

6.5.2 Conditions as at now………………………………………………………………………………………….17

6.5.3 Proposed Solution…………………………………………………..…………………………………………18

6.5.4 Justification …………….………………………………………….………………………………………..18

7. CONCLUSION………………………………………………………………………………………………………………………………19

8. RECOMMENDATIONS………………………………………………………………………..……………………………………….19

9. APPENDIX……………………………………………………………………………………………………………………………………19

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1. ACKNOWLEDGEMENT

I would like to thank First Quantum Minerals and Kansanshi Mine, especially the Training

department, for the opportunity I was given to work at Kansanshi Mine. I thank, the entire

Engineering Department, Mr Joseph Kasaji and Mr Max Simwanza the superintendents, Mr

Peter Mulenga Senior Supervisor, Mwaba Dennis and C. Mpondamasaka my fellow students

and workmates, as well as other students working on attachments there for the guidance

they gave me in trying to help me familiarize with the duties there.

I thank my family and friends, for being there to grant me the support, encouragement and

also for believing in me.

2. SUMMARY

This is a 10 weeks report of my Industrial training at Kansanshi Mine for the partial

fulfilment of the requirements for the award of The Bachelor of Engineering degree at The

University of Zambia.

The report outlines the activities carried out while working at Kansanshi Mine, the details of

these activities, tools and equipment used, precautions taken and the experience obtained.

During the course of the training, I was assigned to work in the department of Engineering

under the direct supervision of Engineer Joseph Kasaji. The work mainly involved working

with centrifugal pumps and HDPE pipes. The work was usually given in form of a mini

project to work out pump head, pressure drops in pipe systems, pump drive specifications

etc.

3. INTRODUCTION

This report covers the general overview of the industrial training experience obtained during

the work period at Kansanshi Mine in Solwezi. The work involved research on steam

turbines for power generation and a great deal of application of fluid dynamics in flow in

closed conduits, and centrifugal pumps.

4. COMPANY PROFILE

Kansanshi Mine is the largest copper mine in Africa, the company is 80% owned by

Kansanshi Mining PLC, a First Quantum subsidiary. The other 20% is owned by a subsidiary

of ZCCM. The mine is located 10 kilometres north of the town of Solwezi and 180 kilometres

North West of the Copperbelt town of Chingola. The company produces copper ore, copper

cathodes, sulphuric acid, copper concentrates and gold.

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5. MACHINERY

5.1 Centrifugal Pumps

These are so called because energy is imparted to the fluid by centrifugal action of moving blades from the inner radius to the outer radius. The main components of centrifugal pumps are (1) the impeller, (2) the casing and (3) the drive shaft with gland and packing. Additionally suction pipe with one way valve (foot valve) and delivery pipe with delivery valve completes the system. The liquid enters the eye of the impeller axially due to the suction created by the impeller motion. The impeller blades guide the fluid and impart momentum to the fluid, which increases the total head (or pressure) of the fluid, causing the fluid to flow out. The fluid comes out at a high velocity which is not directly usable. The casing can be of simple volute type or a diffuser can be used as desired. The volute is a spiral casing of gradually increasing cross section. A part of the kinetic energy in the fluid is converted to pressure in the casing. The following are the various centrifugal pumps were encountered.

5.1.1 Sump Pumps

Figure 15: Sump pumps, exploded view

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5.2. High Head Pump

Figure 16: High head pump, exploded view

5.3. AH Elastomer Pump

Figure 17: AH Elastomer pump exploded view

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6. MAIN ACTIVITIES

During the whole course of attachment, I was working with a fellow student, Chimunya

Mpondamasaka, and we undertook four different projects together. I also handled one

project alone, proposing pipelines to leach tank 3 from the dewatering and pre-leach tanks.

The following are the projects undertaken.

6.1. Propose pipelines to leach tank 3 from dewatering tank and pre-leach

tank.

The project was associated with Contacting of Low Grade Raffinate with Leach Feed

project. However, this project involved connecting two new pipelines to leach tank 3

by tapping from the dewatering tank and another pipeline from pre-leach tank. From

these two lines, another line to leach tank 5 can be connected.

6.1.1 Dewatering tank

There are two lines from the dewatering tank each connected to pp2714 and pp2715

Warman pumps. The line connected to pp2714 had a smaller diameter compared to

the one connected to pp2715, thus the idea was to tap from each line and join these

two to the new line discharging to the leach tank having diameter same as the large

pipeline (pp2715). See diagrams.

Two paths for the new pipe line, option 1 and option 2, were proposed, see figure 2

and figure 3

6.1.2 Pre-leach Tank

There are also two pipelines from the pre-leach tank, pp5001 and pp5002. The

proposed pipeline is shown is figure 1.

6.1.3 Scope of Work

The work involved determining a suitable point, to tap from, on the dewatering lines

and pre-leach line and to find a suitable path to install the new pipe lines.

Thereafter, calculations were carried out to determine the head losses in each

pipeline and discharge static head. From this information, the required operating

conditions of the pumps would be determined from the pump curves. Friction head

losses were calculated using Darcy weisbach equation.

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Figure 18: Proposed pipeline from pre-leach tank to leach tank 3

Figure 19: proposed pipeline from dewatering to leach tank 3 (option 1)

Figure 20: Proposed pipeline from dewatering to leach tank 3 (option 2)

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6.2. C-5 High Lift Pump (pp6022) Motor and Drive System upgrade

The C-5 high lift pump was installed with a 75kw, 1450rpm motor with the drive

pulley of 160mm and driven pump pulley 450 mm. The pump is used as booster

pump to pump water at high pressure to wash CCD thickeners. The pump is required

to take in water at approximately 5bars and pump at 15 bars. However, the pump

was not pumping at the required pressure (12-15bars) and thus the task given was to

determine the conditions, speed, power, the pump need to operate at.

Figure 21: PP 6022 Pump (C-5 high lift pump)

6.2.1 Scope of Work

The work involved performing calculations to determine whether the current installed

motor was sufficient power to run the pump to produce the required pressure and to

determine the required drive system specifications to drive the pump at the required speed.

Thereafter, to determine whether they will be significant pressure drop/losses in the

discharge pipes connected to the pump.

6.2.2 Power calculation

Figure 22: high lift pump inlet and outlet diameter

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Applying Bernoulli’s equation at inlet and outlet of the impeller, neglecting losses from inlet

and outlet:

Therefore selecting a speed of 1500rpm on the pump curve and a flow rate Q =

110litres/sec, efficiency: η = 69%, H =100m, NPSH = 3m. (See pump curve for details)

Figure 23: pump curve

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( ⁄ )( ⁄ )( )

Current installed motor: 75kw 1400rpm

Motor selected is a 200kW, 1400rpm Motor.

6.2.3. Drive system

Figure 24: Open belt drive.

Current installed pulleys, Dm = 160mm, Dp = 450mm

This implies that current pump speed = 497.78 rpm

6.2.3.1 Selection- wedge belt drives

Speed ratio:

o

Design power = 200kw

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Belt section

o SPC

Figure 25: belt type selection chart

Pump pulley limitation

o 315 mm

Table 1: Minimum pulley diameter (extract from “Fernner Drive selection & maintenance manual 2nd

Edition”

Pulley pitch diameters

o Pump pulley = 375 mm

o Motor pulley = 400 mm

Belt length, Centre distance and correction factor

Currently, centre distance = 1060mm

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Table 2: Centre distance tables (extract from “Fernner Drive selection & maintenance manual 2nd

Edition”

o Nearest centre distance to 1060 mm required is 1167mm.

o Belt size is 22N SPC (3550 mm)

o Correction factor = 0.95

Trip rate =

Basic Power per belt

Table 3: Power rating table (extract from “Fernner Drive selection & maintenance manual 2nd

Edition”

o From power rating table the rated power per belt for 375 pitch diameter pulley

at 1500 rpm is 43.24 kw

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Speed ratio power increment

o The power increment for a speed ratio 1.07 at 1500 rpm is 0.90 kw.

Corrected power per belt

o = (basic power per belt + speed ratio power) × correction factor

= (43.24 + 0.9)(0.95) = 41.933 kw

Number of belts required

o = design power/corrected power per belt = 200/41.933 = 4.77

o Therefore, use 5 SPC Wedge belts

Bore sizes

o From dimension tables, a 375 mm × 5 SPC has a maximum metric bore of 90 mm

which is greater than the 80mm pump shaft. The 400 × 5 SPC also has a

maximum of 90mm which is greater than the 70 mm motor shaft.

Motor pulley 400 × 5 SPC

Tape Lock Bush 3535 × 70 mm

Pump Pulley 375 × 5 SPC

Tape Lock Bush 3535 × 80 mm

Fenner Wedge belts 5 × 22N (SPC) 3550

Initial centre distance 1167 mm Table 4: Drive specifications

6.2.3.2 Head loss calculations

Q = 110 l/sec = 0.110 m3/sec D =131.1mm ID v = 1 m/s

V =

= 8.161 m/s Re =

=

( )

= 1069091

λ =

(

) , k= 0.025mm (stainless steel)

λ =

(

) = 0.00217mm

Frictional head

= 0.00215

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Fittings loses

Pressure drop

Applying Bernoulli’s equation between pipe entrance point ‘a’ and discharge end point

b:

+ , Zb– Za= HStatic,

Hloss = minor loses + friction loses = Total Head Loss

( ) ,

( ) ,

Pa = 15 bar = 1500kPa, γ = 9.81kN/m3

( )

Pressure difference,

Figure 26: Pipe system pressure and pressure drops

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The shaft power required to develop the required pressure is 156.39kw at 1500 rpm

therefore, current motor rated 75 kw 1450rpm should be replaced with a motor

rated 200kw 1450rpm. This gives a factor of safety of 43.6kw

The calculated head losses in the pipes produce pressure drops at the discharge end

with a maximum being 3.69bars. The average pressure at the discharge point is

12.13bars.

6.3. Solvent extraction plant 3 (SX3) organic inter-stage bypass pipeline

The solvent extraction plant 3 has 4 pairs of mixer launders all connected in series through HPDE DN800 pipes that allow the flow of organic and aqueous material from one settler to another. However, because of this connection the failure of one of the two middle tanks leads to a complete circuit shutdown. Thus the task was given to design a bypass pipes to overcome the series connection problem. In order to create an indirect route between the launders a y-piece tap on will have to be setup thereby linking the two parallel pipes in order to allow the by-pass process to occur. Due to the flow system’s reliance on gravity the connecting pipes should possess the necessary gradient to achieve the flow of this material. The inversely proportional nature of pressure and velocity will play a major role in the determination of the fluid flow characteristics at different points of the system. To control the discharge a DN630 stainless steel butterfly valve is to be installed

along the connecting pipe. In order to minimize the effects of the water hummer on

the valve it will be placed in a position closest to the connection as possible. The

diagram below shows the design.

Figure 27: project design

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Calculations were carried out to determine the head losses, pressure drops in the

bypass lines.

6.4. Plant Sump pump Catalogue

With great concern of high rate of wear sump pumps parts such as impellers, and

casings, an up to date record of all sump pumps around the plant was required for

easy identification, tracking of spare parts needed and to determine whether the

pumps were operating at their best efficiency points BEP. The record is to contain

detailed information about each sump pump, such as pump size, pump type,

installed motor, drive system, diameter, length, head loss and discharge static head

of discharge pipeline. This project was given to my partner and I.

The project involved going around the plant and recording all the sump pumps, the

motors installed, pulleys and belts, and measuring discharge pipe lengths and static

head, and there after calculating the head losses through the discharge pipes. This is

still an on-going project.

6.5. AP5 Steam Turbine Research Project

6.5.1 Scope of Work This project involves the design and configuration of a mini- steam electricity generating power station at acid plant 5 (AP5) in order to optimize on the steam that’s being produced by the boiler, thereby creating alternative power sources for the plant. The viability of the project will be checked, by determining whether the steam being lost is enough to produce sufficient amounts of electricity. Power calculations will be carried out to determine the sizing and performance characteristics of the turbine to be installed. Further calculations will be carried out to determine if super heating or reheating will be an option and if so what kind of super heater should be used. Turbine selection with reference to installation and maintenance costs will also be looked into. This is still an on-going project.

6.5.2 Conditions as at now

AP5 currently has the potential to produce 60tonnes/hour of steam with only a maximum of 20tonnes/hour being used for acid production, with around 40tonnes/hour of steam being expelled into the atmosphere with no return. However due to the fact that AP5 is a relatively new plant its demand for steam is not as much as it should be under high production. Mass flow rates of 33.1tonnes/hour and 46.4tonnes/hour was being produced by the plant during their 3rd week of operation. About 1.8MW of power is used at AP5 alone for steam generation, and this accounts for less than a third of this steam being used.

There is a strain in the electricity power lines in Solwezi due to the high demand for power by the mine which used around 132.7MW of power in the month of

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September alone. This also has a bad bearing on the electricity tariffs that the company has to meet. The supply of water to AP5 is in large amounts in order to meet acid production demands and as such to lose this water in the form of steam is a huge loss.

6.5.3 Proposed Solution

Steam from AP5 can be trapped before it’s expelled into the atmosphere and channeled into a super heating unit, where its moisture ratio is further reduced and as such increasing its pressure. An increase in pressure leads to a high power input which is able to run a turbine and possibly generate enough electricity for utilization. Saturated steam being expelled from the turbine will be condensed and pumped into the boiler for a continuation of the process without no or few loses in the process.

6.5.4 Justification

Financial benefits for the company will obviously be experienced as a result of

cuts in electricity tariff payments with the turbine being able to cater for large

areas and equipment needing a supply of electricity in order to perform their

functions. As a result of a continuous cycle setup in which water being lost

through the steam vent system is being trapped, condensed and sent back into

the boiler, the quantity to water being used up is less.

With a reduction in the length of the vent pipeline, the risk of injury through burns is reduced and hence the safety of the mine populous is made better. Through the maximization of all available resources the plant can be said to be running effectively because every single resource is being used to generate some sort of power or energy.

Figure 28: PRESSURE, TEMPERATURE AND MASS FLOW RATE DISTRIBUTION AT OPTIMUM CONDITIONS

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7. CONCLUSION

Working at Kansanshi Mine was a worthwhile experience in that knowledge and skill

were gained especially in fluid mechanics. The various projects undertaken required

application of a lot of concepts learnt in class and thus gave more insight to design

and application of engineering concepts in the industry, the mine. The machinery and

new technologies encountered were of greatly appreciated as the principles learnt in

class, Thermodynamics, Dynamics, Material Science and Fluid Mechanics, were seen

applied in reality.

8. RECOMMENDATIONS

1. A database for all pumps should be prepared and kept updated for any changes.

This should be made available and accessible for the entire engineering

department. The database should contain information such as, pump name,

pump type, discharge pipe diameter and length, discharge static head, motor

size, pulleys and belt drive, pump curve with operating point indicated.

This will speed up troubleshooting, upgrades and spare parts replacement.

2. Internet access should be made available to students. The IT department should

come up with way of preventing internet abuse so that the majority internet

users are protected. This is because internet is a global library which is very

helpful with research projects.

3. The company should continue training students in order to bridge the gap

between theory and practice.

4. The good attitude towards helping students, being trained, to understand the

various aspects of the workings of the company should be encouraged.

9. APPENDIX

APPENDIX A

Abbreviations

AP5: Acid Plant 5

CCD: Counter Current Decantation

SX: Solvent Extraction

REFERENCES

- Fernner (2006), Drive Selection & Maintenance Manual 2nd Edition

- R.K. Rajput (2010), A Text Book of Fluid Mechanics and Hydraulic Machines, SI units.

- R.S. Khurmi, J.K Gupta (2005), A Textbook of Machine Design, 1st Multicolor Edition