A SEMINAR REPORT ON SURFACE AND UNDERGROUND INSTALLATIONS Submitted in fulfillment of Industrial Training Rajasthan Technical University

Session: 2010-2011 Guided By: Mr. Ved Prakash Lecturer Mechanical Engineering Engineering Submitted By: Tarun Kumar Dhanuka IV Year (ME/08/58) Mechanical

DEPARTMENT OF MECHANICAL ENGINEERING POORNIMA COLLEGE OF ENGINEERING ISI-6 RIICO INSTITUTIONAL AREA SITAPURA, JAIPUR-302022 RAJASTHAN

TABLE OF CONTENTS

Declaration Certificate Acknowledgement List of figures

i ii iii iv

CHAPTER 1. INTRODUCTION

1.1 1.2 1.3 1.4 1.5 1.6

Introduction to HZL, Rajpura Dariba Mine Background of HZL Products History and Milestones Success Track Record Key Financial Information

CHAPTER 2. DIFFERENT PROCESSES

2.1 2.2 2.3 2.4 2.5

Mining Primary Crushing Process and Instrumentation Secondary/Tertiary Crushing Process & Instrumentation Grinding (Stream 1) Process Grinding (Stream 2 & 3) Process & Instrumentation

2.6 2.7 2.8

Reagents Process & Instrumentation Flotation Process & Instrumentation Thickners Process & Instrumentation

CHAPTER 3. CORPORATE SOCIAL RESPONSIBILITY

3.1 3.2

Corporate Social Responsibility Static and Dynamic Information about HZL

CHAPTER 4. HEALTH, SAFETY AND ENVIRONMENT

4.1

Environment Safety

DECLARATION

I hereby declare that the work which is being presented in the seminar report entitled Surface and Underground Installations in fulfillment of Industrial Training from Hindustan Zinc Limited, Udaipur in Mechanical Engineering affiliated to Rajasthan Technical University, Kota and submitted to the Department of Mechanical Engineering of Poornima College Of Engineering, Jaipur, is an authentic record of my own work carried out under the guidance of Mr. Ved Prakash during the session 2010-11 (Even Semester). The matter represented in this report has been submitted by me.

Tarun Kumar Dhanuka Jaipur Date:

i

Poornima College Of Engineering, Jaipur Department Of Mechanical Engineering

CERTIFICATE

This is to certify that the seminar report entitled Surface and Underground Installations has been submitted by Tarun Kumar Dhanuka (ME/08/58), student of IV year (VI semester) Mechanical Engineering branch in the fulfillment of Industrial Training from Hindustan Zinc Limited, Udaipur . The report has been found satisfactory and approved for submission.

(Mr. Krishna Kumar Purohit) Seminar Coordinator ME Deptt. (Mr. Deepak Kumar) HOD, ME Deptt. ii

(Mr. Ved Prakash) Seminar Coordinator ME Deptt. (Mr. R.P.Rajoria) Director-PCE

ACKNOWLEDGEMENT

With due respect to all we would offer our sincere thanks to Mr. R.C.MEENA who encouraged and helped us to complete our training successfully. We are highly grateful to Mr. C.K.JAIN who really justified the meaning of the phrase MENTOR by his unceasing and unanimous support. We are also indebted to Mr. HARBINDER SINGH who as a trainer took our responsibility and scheduled us for this training. Furthermore we express our thanks to personnel of all other departments especially Mr. G.K.ARORA, Mr. Naveen Paliwal who have been instrumental in the materialization of the report.

TARUN KUMAR DHANUKA (ME/08/58) MECHANICAL ENGINEERING

iii

LIST OF FIGURES

List of all the figures used is as follows:1). Flow chart of Success Track Record 2). Mining and Drilling 3). Primary Crushing 4). Secondary/Tertiary Crushing 5). Ball and Rod Mill 6). Magnetic Flow Meters 7). The Probe 8). Flotation Process 9). Froth Analyzer 10). Thickeners 11). Thickeners when empty

iv

CHAPTER - 1

INTRODUCTIONHINDUSTAN ZINC LTD. (HZL) is the only integrated Zinc manufacturer in India and owns captive Zinc mines that supply complete requirement of Zinc Concentrate for its smelters.

Rajpura Dariba Mines(76 kms north-east of Udaipur, Rajasthan, India) OVERVIEWRajpura Dariba Mine has annual ore production capacity of 0.90 million tonnes and achieved a production level of 21.96 kt of contained zinc and 5.35 kt of contained lead in FY 2010. Bulk concentrate production at Rajpura Dariba has resulted in significant recovery improvements in Zinc, Lead and Silver.

BACKGROUND INFORMATIONRajpura Dariba Mine is an underground mine, commissioned in 1983. It is located about 75 kilometers north-east of Udaipur in the State of Rajasthan in India and is well connected with roads. Water requirement is met from the Matrikundia dam on Banas River. Power requirement is met by our captive power plants. Any shortfall is met by the State grid.

Total Reserves and Resources are 42.2 million tonnes as on 31st March 2010.The mine is equipped with world-class infrastructural facilities including the latest and the best machineries; in-house central workshop vehicle service centre and repair shop equipped with requisite facilities.

CERTIFICATIONThe management system of Rajpura Dariba comprises of: the Quality System ISO 9001:2008, the Environmental System ISO 14001:2004 and the Occupational Health, Safety Management System OHSAS 18001:2007, SA 8000:2008 and 5S Certifications.

PRODUCTS1) ZINC We produce refined zinc metal which is used in a number of applications including glavanising, oxides, die castings and alloys. We produce zinc in a variety of gradesy y y

Special High Grade (SHG) High Grade (HG) Prime Western (PW)

Our Special High Grade zinc products are LME registered products under the brand namesy y

HZL SHG 99.995 Vedanta SHG 99.995

Special high grade and high grade zinc are available in standard ingots of 25 kgs and Jumbo ingots of 1,000 kgs each.. Prime Western is also available in the standard ingots form of 25 kgs. Applications Of Zinc Over 11 million tonnes of zinc is produced annually worldwide. Around 48% of the amount is used for galvanizing to protect steel from corrosion. Approximately 17% is used the production of zinc base alloys like die castings etc. Nearly 10% of the zinc is also utilized for compounds such as zinc oxide and zinc sulfate and about 11% is used in the alloys especially brass.

A) Galvanising: Zinc is one of the best forms of protection against corrosion and is used extensively in building, construction, infrastructure, household appliances, automobiles, steel furniture, and more. Galvanising accounts for around 48% of global zinc usage. B) Zinc Oxide:

The most widely used zinc compound, zinc oxide is used in the vulcanisation of rubber, as well as in ceramics, paints, animal feed, pharmaceuticals, and several other products and processes. A special grade of zinc oxide has long been used in photocopiers. 10% of global zinc usage is in this segment. C) Die Castings: Zinc is an ideal material for die casting and is extensively used in hardware, electrical equipments, automotive and electronic components. 17% of zinc used in the word is through Die Castings. D) Alloys: Zinc is extensively used in making alloys, especially brass, which is an alloy of copper and zinc. Alloy accounts for around 11% of global zinc usage. E) Rolled Zinc:

Zinc sheets are used extensively in the building industry for roofing, flashing and weathering applications. These are also used in graphic art to make plates and blocks, as well as battery callouts and coinage.

2) LEAD We produce refined lead at our Chanderiya Smelting Complex, which is LME registered under the brand name of "Vedanta 99.99". Lead metal is used in a number of applications including battery segment, lead-based pigments, and cathode ray tubes. Our refined lead metal is available in standard 24 kgs ingots.

Applications Of Lead The battery sector is the single largest consumer of lead, accounting for around three-quarters of the demand. It can be sub-divided into the following groups: SLI (Starting-Lighting-Ignition) batteries, which currently accounts for around half of the total lead demand. These are mainly used in cars and light vehicles, but are also found in other applications such as golf carts and boats. SLI battery demand in turn can be split into original equipment and replacement, with replacement demand outstripping original equipment demand by about 4:1 in mature markets. Industrial batteries, which currently consumes around a quarter of the total lead produced. This sector can be split roughly 50:50 into stationary and traction batteries. Stationary batteries are principally used in back up power supply systems; traction batteries are used for motive power in equipment such as forklift trucks and motorised wheelchairs. The remainder is used in non-battery applications. The second largest current end use of lead for non-batteryapplications, accounting for around 8% of lead consumption, is the chemical industry, in the form of lead-based pigments and other compounds. Principal markets are for cathode ray tubes used in television screens and computer monitors, and for Poly Vinyl Chloride (PVC) stabilisers. 3) BY PRODUCTS SILVER y We are India's largest and one of the world's leading primary silver producer. We produce refined silver at Chanderiya Smelting Complex; it is recovered as a byproduct of lead metal. y We produce high quality silver bullion having a minimum purity of 98.5% to 99.5% of silver; it is casted in the form of bricks weighing 30 kgs.

Applications Of Silver y Silver is used in a number of varied applications like the most important uses of silver being the industrial and decorative uses,

photography, and jewelry & silverware; together, these three categories represent more than 95 percent of annual silver consumption. Silver's unique properties restrict its substitution in most applications. Industrial applications: y brazing alloys, electrical contacts, high capacity silver-zinc or silver-cadmium batteries, printed circuits and other electronic applications. Other applications: y Silverware, jewellery, Silver plating, photography, Dental alloys and more. CADMIUM We are India's largest cadmium producer. We recover cadmium from our zinc smelting process as cadmium is mainly found in association with zinc ores. We produce high quality cadmium pencils having a minimum purity of 99.95% to 99.99% of cadmium; it is casted in the form of pencils weighing from 250 gms to 500 gms. Applications Of Cadmium The single most important use of cadmium is in the production of nickelcadmium ("Ni-Cad") batteries. About three quarters of the cadmium consumed annually is used to make batteries. Cadmium is also useful in a number of other applications as paint pigments, low-temperature melting alloys, etc.

History & MilestonesHistory Hindustan Zinc Limited was incorporated from the erstwhile Metal Corporation of India on 10 January 1966 as a Public Sector Undertaking.

Milestones2011y y y

Commissioned 1.50 million tonnes per annum concentrator at Silverrich Sindesar Khurd Mine Commissioned 160 MW (80X2) Captive Power Plant at Dariba Smelting Complex Around 48 MW addition in wind power generation capacity

2010y

y

Rampura Agucha Mine expansion from 5.00 million tonnes per annum to 6.00 million tonnes per annum, increasing the total mining capacity of the Company to 8.40 million tonnes per annum. Commissioned the 210,000 tonnes per annum Hydrometallurgical Zinc Smelter at Rajpura Dariba, increasing the Zinc & Lead metal production capacity to 964,000 tonnes per annum (879,000 tonnes of Zinc and 85,000 tonnes of Lead).

Success Track Record

Fig.:- Flow Chart

Our ongoing exploration activities have yielded significant success with thegross addition of 22.1 million tonnes to reserves and resources, prior to a depletion of 7.5 million tonnes in FY 2011. Contained zinc-lead metal has increased by 1.4 million tonnes, prior to a depletion of 0.84 million tonnes during the same period. Total reserves and resources as at 31st March 2011 were 313.2 million tonnes containing 34.7 million tonnes of Zinc-Lead metal and 885 million ounces of Silver. The reserves and resources position has been independently reviewed and certified as per the JORC standard. In FY 2011, a total of 68,200 meters of core and non-core drilling was completed at various exploration sites throughout the mines and tenements. Significant R&R additions of 18.96 million tonnes were reported from Rajpura Dariba belt and Zawar.

Key Financial Information

Key Financial Highlights for FY 2011y y

y

y y y y

Revenue of Rs. 9,912 Crore and PBDIT of Rs. 6,454 Crore. Highest ever production of Zinc-Lead Mined metal, Refined Zinc metal and Silver. Stable operating costs, supported by higher volumes and increased operational efficiencies. Return on capital employed (ROCE) continues to be strong at 56.06% Strong balance sheet with shareholders fund base of Rs. 22,533 Crore. Cash flow and liquid investments of Rs. 14,965 Crore. Earnings per share of Rs. 11.60.

Key Performance IndicatorsParticulars FY 2011 FY 2010 FY 2009 FY 2008 FY 2007 8,560 6,639

Revenue (Rs Crore) PBDIT (Rs Crore) ROCE (%) EPS (Rs)

9,912 8,017 5,680 7,878 6,454 5,392 3,665 6,231

56.06% 57.51% 44.07% 93.58% 138.96% 11.60 9.56 6.45 10.40 10.51

CHAPTER 2

MINING & DRILLING

Fig.:- Milling & Drilling BMCL established this Mines in 1991 with an estimated depth of 170m as Open Cast mines. Initially, production capacity was 0.9 million tones/annum with strip ratio of 1: 4.5 . Ore body has 15% metal content, out of which 13% is Zn and rest 2% is Pb. Rock type of ore is GBSG i.e Garnate Biotite Siliminite Gneiss . Production capacity was then increased to 2.4 MTPA & then to 3.75 MTPA and in last year it was 4 MTPA out of 34 MTPA.

1. 2. 3. 4. 5. 6.

This year production is estimated to be mammoth 5 MTPA out of total excavation of 54 MTPA. Ore body is 1.6 Km in length with average width of 58 m. Total Depth of ore body is 1 Km. Dipping angle of ore body is 65-70 degree. Present depth up to which ore has been mined is 160 m with a width of 800m. Various Mining machinery are used for excavation which includes:EXCAVATORS DUMPERS (BH & CAT) DRILLING MACHINE DOZERS GRADERS WATER SPRINKLER At present 15000 TPD of ore out of 1,00000 TPD of excavation is fed to beneficiation plant (stream 1,2&3). A total of 40 TPD explosive is used. Out of total depth of ore body i.e. 1Km It is being planned that 400m of ore body would be mined out by Open Pit method. And rest i.e. 600m would be excavated by Underground mining method.

PRIMARY CRUSHINGAfter the mining stage is over ore is brought to the ore beneficiation plant where it is first processed in the primary crushing plant . There are two primary crushers:1) Superior mk-1 54-74 gyratory crusher. (old)(375KW) 2) Superior mk-2 54-75 gyratory crusher. (new)(450KW) 54 means feed opening (inches) and 74(or 75) means mantle diameter. mk-1 means units manufactured prior from 1994 by metso minerals and mk-2 means from 1994 to present day.

Big blocks of ore material is crushed to a particle size of (-200mm). The crushed product (size = -150 mm) is then carried to the coarse ore stockpile(COS) via apron feeder (size : 1500 mm width, 8500 mm length) and a series of sequential transfer conveyors. The capacity of coarse ore stockpile is such that it is sufficient to cater the needs of main processing plant for at least five days. The ore processed in the Gyrator of primary crusher house is then forwarded to apron feeder with the help of crushed ore hopper. Apron feeder passes crushed ore to coarse ore storage though product conveyor, BH conveyor and tripper belt conveyor . Crusher capacity is dependent upon feed gradation, material bulk density and moisture content..

Fig. :- Primary Crusher

INSTRUMENTATION INVOLVED IN PRIMARY CRUSHER:-

1. RADIOACTIVE LEVEL SENSORS (NUCLEONIC LEVEL GAUGES). 2. UNDER SPEED SWITCH/ZERO SPEED SWITCH. 3. BELT SWAY SWITCH. 4. ROPE WAY SWITCH/PULLCORD SWITCH. 5. INDUCTIVE PROXIMITY SWITCHES. 6. WEIGHTOMETER. 7. SOLENOID VALVE. 8. ANNUNCIATOR SYSTEM. 9. PAPERLESS RECORDERS. 10. TEMPERATURE SWITCH.

SECONDARY/TERTIARYCRUSHING

Fig.:- Secondary/ Tertiary Crushing

y From COS the ore is send to the secondary and tertiary crusher before feeding to stream-1 for beneficiation process. Crushed ore of size (-150mm), coarse ore storage is fed into 5nos.Reciprocating feeder through crushed feed conveyor the material is brought to double disc vibrating screen. The underflow of the d.d.v screen is passed to fine ore conveyor and overflow material from first screen of d.d.v screen is passed to secondary cone crusher From there it is transferred to crusher product conveyor while the overflow form the second screen of d.d.v. Screen is passed to crusher product conveyor . The material from u-56 is stored in tertiary crusher bin u-62 a, b, c through a flap gate mechanism & tertiary bin conveyor (u-58) & crusher

bin feed conveyor (u-60), and through belt feeders the material is transferred to 3nos. Vibrating screen and u/f is transferred to tertiary crushers (u-69 a, b, c) while the o/f goes to fine ore bin conveyor (u-71) after through fine ore transfer conveyor (u-73) and by there way gate mechanism a1, b1, c1 it is transferred to fine ore bin new or old through fob tripper conveyor (u75a, b) respectively .the ore particle size of after sec. Crusher is of size (-50mm) and that from tertiary crusher is (-19mm).

FINE ORE BINFine ore bin having a size of 19mm are stored in two fine ore bins each having a capacity of 4500 MT each. The ore present in the fob is feeded to ROD MILL(Stream -1). FOBs have air blaster which are used to disassemble the ore which is stuck to the walls of the FOB.

INSTRUMENTATION INVOLVED IN SECONDARY/TERTIARY CRUSHER

1. LEVEL SWITCH(FLOAT TYPE) 2. UNDER SPEED SWITCH/ZERO SPEED SWITCH. 3. BELT SWAY SWITCH. 4. ROPE WAY SWITCH/PULLCORD SWITCH. 5. INDUCTIVE PROXIMITY SWITCHES. 6. WEIGHTOMETER. 7. SOLENOID VALVE. 8. ANNUNCIATOR SYSTEM. 9. TEMPERATURE SWITCH. 10. PRESSURE SWITCH

11. LEVEL SENSOR

PRESSURE SWITCH A pressure responsive switch senses a change in pressure and responds to such changes by alternately making and breaking an electrical connection. Pressure-sensitive switches are used where it is desired to switch apparatus ON or OFF at predetermined pressures. Pressure switches include set-point pressure switches that actuate when a specified pressure is reached and pressure measuring switches that are capable of measuring the ambient pressure and reacting accordingly.

OPERATION A pressure responsive switch generally comprises a diaphragm responsive to a pressure change, a rigid ring for securing the diaphragm, and a pair of electrically conductive contacts that break contact based on movement of the diaphragm.

Mechanical pressure switches typically provide an output signal in the form of a switch closure in response to application of mechanical or atmospheric pressure. A differential pressure switch is a device which utilizes differential fluid pressure from low and high pressure sources to actuate an electric switch at a pre-set actuation point. Differential pressure switches are commonly employed to control the operation of snap action switch.

FLOAT OPERATED MAGNETIC LEVEL SWITCHMagnetic Level Switches are specially suitable for high and low level signalisation or automatic level control (by starting & stopping pumps or opening & closing of valves) in pressurised or non-pressurised vessels. Horizontal mounting type directly on vessel or on External Chamber.

FEATURES Magnetic Transmission: Switch entirely glandless. Switch housing nonrotatable (rotatability not desired in case of horizontal mounting). Suitable for horizontal mounting. Adjustable Differential Attachment for higher differential. Float with extension Rod for Longer nozzles. Snap acting/Air Break type contacts or Microswitches..

PRINCIPLE OF OPERATION With the rise of liquid level, the float moves up thereby lowering the tailpiece (and vice versa). The tailpiece magnet, by principle of repulsion pushes a magnet inside Level Switch Body.

The Magnet makes or breaks contacts (Air-break type) or operates one or two Micro switches. Switches operated by snap action due to principle of repulsion.

GRINDING CIRCUIT(STREAM 1)There are three identical grinding circuits each comprising of y one rod mill in open circuit and y one ball mill in closed circuit.

Fig.:- Ball and Rod Mill

S.No. 1 2 3 4 5 6 7

Description Dimensions dia (m) x length (m) Grinding Media Motor rating(K.W.) 80% passing feed size 80% passing product size % solid inside mill RPM of the mill

Rod Mill 2.7 x 3.7 Rods of Cr-MnFe alloy are used 350 19mm 1mm 78-80% 17.2

Ball Mill 4.4x5.5 Balls of Cr-Mn-Fe alloy are used 1600 1mm 63 microns 68-72% 14.6

PROCESS DESCRIPTIONy Products from rod mill are dumped into the first stage sump. y From this sump it is feeded to the primary cyclone which has rubber lining in it. y Overflow from first stage goes to second stage classification cyclones having diameter of 15. y The underflow from the cyclone is send to the ball mill and then are fed to primary cyclone( 1st stage classification) having a diameter of 20. y Underflow from both stages goes to ball mill.

GRINDING CIRCUIT(STREAM 2&3) Installation of Stream-2 & Stream-3 has greatly increased the overall production & has reduced the cost of Zinc. Various instrumental changes have been made. Unlike Stream-1 the ore from COS is directly feeded into the SAG mill. SAG stands for Semi Autogenously Grinding & SAG mill is of size 7.0 mtr dia x 3.5 mtr length. The grinding takes place due to two reasons: o Ore to Ore impact and

o Ball to Ore impact. The capacities of SAG mills employed in Stream-2 & Stream-3 are 200 TPH & 140 TPH. Weight of the SAG mill is 10,500 Kg & it consumes approx 2500KW power. In SAG mill functioning three things are being focused namely: o To control Power o To control Weight o To control % solid . o An inline magnetic separator for picking up further extraneous material is installed on pebble reject conveyor. o A metal detector installed, monitors for any metallic object entrained in the stream. o While the belt weigh scale monitors & controls the tonnage of ore fed to SAG mill. o Sag mill crushing: balls(Cr-Mn-Fe alloy) are used. o The grinded ore is passed through the vibrating screen along with the jet of water(for easy flow).

The undersized particle is fed to the first stage sump and the oversized particle is regrinded by the sag mill. From this sump it is feeded to the primary cyclone which has rubber lining in it. Overflow from first stage goes to second stage classification cyclones. The underflow from the cyclone is send to the ball mill (5.0 Mtr dia X 7.8 Mtr length). . and then are fed to primary cyclone( 1st stage classification) Underflow from both stages goes to ball mill The grinding circuit feed to flotation is sampled for continuous particle size analysis (PSI 500 & PSM 400 MPX) and the results transmitted to the control system for optimizing control of the grinding circuit.

INSTRUMENTATION INVOLVED IN THE GRINDING PROCESS WEIGHTOMETERS FLOW CONTROLLERS ON THE FEED SIDE OF ROD MILLS. LEVEL CONTROLLERS (ULTRA SONIC LEVEL CTRL.) FLOW TRANSMITTERS(ELECTROMAGNETIC) DENSITY CONTROLLERS.(RADIOACTIVE)

IN THE BALL MILL: HI-LIFT PUMP : PRESSURE SWITCH GAUGE OF 20 KG/CM2

DRIVING/NON-DRIVING END: LUBRICATION PUMP PRESSURE SWITCH OF 1.5 KG/CM2 TEMPERATURE SENSOR (RTD TYPE)

MAIN GEAR BOX: FLOW SWITCH PRESSURE SWITCH OF 0.8 KG/CM2 RTDS SLURRY ANALYZERS USED: IN STREAM ANALYSER (I SA) : STREAM 1

COURIER 6 SL : STREAM 2 MULTI STREAM ANALYZER (M S A) : STREAM 3 PLCS & DCS

MAGNETIC FLOW METERS FOR CONDUCTIVE LIQUIDSThe magnetic flow meters do not have any moving parts and are ideal for water application or any dirty liquid which is conductive. A conductive process fluid is run through a magnetic field. As it creates an electric charge through its interaction with the field, the charge is measured to find the speed of the flow.

PRINCIPLE:The operating principle of magnetic flow meters is based upon Faraday's Law of electromagnetic induction, It states that a voltage will be induced in a conductor moving through a magnetic field." FARADAY'S LAW: Mathematically E = KBDV Where E = INDUCED VOLTAGE, B = STRENGTH OF THE MAGENTIC FIELD, D = CONDUCTOR WIDTH, V = VELOCITY OF THE CONDUCTOR.

Fig.:- Magnetic Flow Meters

OPERATIONThe magnitude of the induced voltage E is directly proportional to the velocity of the conductor V, conductor width D, and the strength of the magnetic field B. Magnetic field coils placed on opposite sides of the pipe generate a magnetic field. As the conductive process liquid moves through the field with average velocity V, electrodes sense the induced voltage. The width of the conductor is represented by the distance between electrodes. An insulating liner prevents the signal from shorting to the pipe wall. The only variable in this application of Faraday's law is the velocity of the conductive liquid V because field strength is controlled constant and electrode spacing is fixed. Therefore, the output voltage E is directly proportional to liquid velocity. This voltage is picked up by sensing electrodes mounted in the meter tube and sent to the transmitter which takes the voltage and calculates the flow rate based on the cross sectional area of the meter tube.

ULTRASONIC LEVEL MEASUREMENTPRINCIPLE An ultrasonic level measurement system consists of an ultrasonic transmitter and an ultrasonic receiver.

The reflected signals from different interface levels, in the measurement volume are received by ultrasonic receiver, as the signals are the function of density of the medium and speed of sound in the medium. The time lapse between firing the sound burst and receiving the return echo is directly proportional to the distance between the transducer and the material in the vessel. This basic principle lies at the heart of the ultrasonic measurement technology and is illustrated in the equation: DISTANCE = (VELOCITY OF SOUND X TIME)/2

Fig.:- The Probe

REAGENTSS. No 1 2 Name of reagent MIBC KEX Purpose Used as Frother & for stabilizing the bubble Collector for lead Strength (%) -1.5 Points of addition Pb rougher feed Pb conditioner Pb rougher II Pb Scavanger II Zn conditioner Zn rougher I Zn rougher II Zn conditioner Pb rougher II Zn cleaner III Rod mills 1,2 & 3 Pb Cleaner 1 Zn cleaner Pb cleaner Zn conditioner Zn cleaner

3

SIX

Collector for zinc

4%

4 5 6

CuSo4 NaCN Nigrosine

Activator for zinc Depressant for pyrites Depressant for graphite

8.0% 1.0% 3%

7

Lime

Used as pH modifier.

1.0%

INSTRUMENTS USED IN REAGENT SECTIONy y y CONTROL VALVE (BALL TYPE) MAGNETIC FLOW METER MIBC DOSING PUMP

COMPRESSOR Compressors are used to compress air at high pressure. There are total 12 compressors used in Stream-1 and Stream-2. Two types of comp. used in this plant: o Screw air comp: used for higher capacitance. o Reciprocating comp: used for lower capacitance.

Its measuring unit is CFM (cubic feet/min).

Compressed air is utilized as:1. Plant air: From here it is supplied to Pressure filters and used for the process of drying and pressing of the slurry. 2. Instrument air: It is of 7 Kg/cm2 of pressure. This air should not have any moisture content in it therefore it is first passed through the air drying system.

PROCESS Air is sucked from the atmosphere and then compressed. Dust particles are removed through filters. Then the air is sent to dryer where moisture is removed. Two dryers are used: Dececant type: it has Al2O3 walls which are replaced periodically. Refrigerator type: it is more efficient and sucks the moisture content of air. Compressed air is then transferred to various sections of the plant. Hot air suction is avoided in comp.

INSTRUMENTATION INVOLVED IN COMPRESSOR FLOW SWITCH PRESSURE SWITCH DPT PT MAGNETIC FLOWMETER TEMPERATURE SCANNER AUTOMATIC DRAIN VALVE RTD AIR DRYER SYSTEM SOLENOID VALVES

BLOWER It consists of a fan which sucks the atmospheric air. This air is then transferred through channels to the agitators of floatation cells.

INSTRUMENTATION INVOLVED IN BLOWERS COOLING WATER FLOW SWITCH LUBE OIL PRESSURE SWITCH RTDS VIBRATION MODULE/SENSOR TEMPERATURE SCANNER

FLOTATION

Fig.:- Floation

Flotation is a selective process and can be used to achieve specific separation from complex ores such as lead-zinc, copper-zinc, etc.

PRINCIPLE OF FLOTATION Froth flotation utilizes the difference in physico-chemical with reagents, such difference in surface properties between the minerals within the flotation pulp become apparent and, for flotation to take place an, air bubble may able to attach itself to a particle, and lift it to water surface figure. In flotation concentration, the mineral is usually transferred to the froth, float fraction, leaving the gangue in pulp or tailing. The air bubble stick to the mineral particles if they can displace water from the mineral surface, which happen if the mineral to some extent is water repellant or hydrophobic. Having reached the surface, the air bubble continue to support the mineral particle if they form a stable froth; otherwise they will burst and drop the mineral particle. To achieve this condition it is necessary to use numerous chemical reagents known as flotation reagents.

LEAD FLOTATION From the secondary cyclone collection the product flows to a 4.5m*4.5 m lead conditioner tank, sized to provide 10 minutes retention time. Conditioner overflow provides a bank of 17*16m lead rougher/ scavenger flotation cells in a 4-3-3-4-4 configuration. Individual autonomic level control is provided in each junction box. Tailing from the Pb rougher/ scavenger flotation tank is pumped to first of two zinc flotation conditioners. Air is injected into flotation cells from high pressure air blowers. There are three stages of lead rougher concentration cleaning

the first two stages each in-corporating 3*3 m cells and the third stage 2*3 m cells. First stage cleaner tailing and scavenger concentrate gravitate to the lead regrinding circuit.Comprising a 2.7m dia 4.27m long ball mill in closed circuit with three 10 hydro cyclones. Regrinding cyclone overflow gravitates to the Pb rougher flotation conditioner. From third cleaner stage, the final lead concentrate of the grade around 50% lead is pumped to the feed tank ahead of lead concentrate thickener. Reagents addition at various points through out circuit is programmed through Digital Distributed Control and fed by metering pumps. ZINC FLOTATION

Tailing from the lead rougher/ scavenger bank is pumped to the first of the two 4.5m*4.5m size zinc conditioners giving approx. 12 minutes total retention time. The second conditioner overflows to a bank of 15*38m rougher/ scavenger flotation cell. Individual autonomic level control is provided in each junction box. Tailing from the rougher/ scavenger bank is automatically analyzed and pumped to the tailing thickener. Four stages of zinc rougher concentrate cleaning are provided, the first two stages each have 5*16m cells, third stage 4m*16m and fourth stage 4*8m + 1*16m cells. Zinc scavenger concentrate along with zinc cleaner tails is fed to regrind circuit. The zinc regrind circuit comprises 3.2m dia 5.49m dia ball mill in closed circuit with four 10 cyclones. Zinc regrind cyclone overflow is transferred to first zinc rougher concentrate prior to cleaning. Sr.No 1 2 Description Pb conditioner Pb rougher scavenger

Population 1 9+10

3 4 5 6 7 8 9 10 11

Pb 1st cleaner Pb 2nd cleaner Pb 3rd cleaner Zinc conditioner Zinc rougher-scavenger Zinc 1st Cleaner Zinc 2nd cleaner Zinc 3rd cleaner Zinc 4th cleaner

3 3 2 2 10+9 10 5 4 1+4

INSTUMENTATION INVOLVED IN FLOATION PROCESS1. 2. 3. 4. 5. 6. LEVEL TRANSMITTER CONTROL VALVE(BUTTERFLY TYPE) DPT I/P CONVERTER Ph TRANSMITTER ANNUBARS

7. FROTH ANALYSER SYSTEM

FROTH ANALYSER SYSTEMFroth Master is a tool for real-time froth surface analysis. The Froth Master system measures several essential properties of froth appearance including froth speed, bubble size, froth stability and froth color and provides statistical data related to these variables. The measured froth properties, together with on-stream analyzer assays, enable expert control of the flotation circuit.

BASIC PRINCIPLE A typical Froth Master installation has several froth imagers mounted on top of flotation machines. The imagers are networked through intelligent connection boxes to a Froth Manager station, which acts as a gateway to the plant automation system and office network. The Froth Manager station can run optional ACT expert system applications for flotation circuit froth recovery, mass balancing and adaptive cell level controls. The Froth Master consists of a high resolution color camera, controlled light and optional sun shade. The imager module is designed for flotation plant environment and is IP65 rated.

Fig:- Froth Analyser

THICKENERS

Fig.:- Thickeners

PROCESS After froth flotation the products i.e., Lead concentrate & Zinc concentrates are pumped to respective thickeners. Tailing is disposed off to tailing dam via neutralization tank. All the existing four thickeners have been upgraded & retrofitted to hirate thickeners. Thickened slurry of lead & zinc thickener underflow is sent to respective concentrate holding tanks after which it is subjected to filtration.

Sr.No

Description

Lead

Zinc

Lead

Tailing

1 2 3

Diameter Feed % solids Underflow % solids

14m 40-55 70-75

Thickener 25m 35-40 65-70

Thickener 14m 35-40 65-70

55m 20 22-25

Fig.:- Thickeners when empty

CHAPTER 3

CORPORATE SOCIAL RESPONSIBILITY

We continue to impact over 500,000 lives through our relentless Corporate Social Responsibility (CSR) initiatives. We are committed to raise the quality of life and social well-being of communities where we operate. We believe in engaging with our stakeholders in two-way, open dialogue, which is the key to the development of sustainable communities. We work to establish and maintain our "social license to operate" in the local communities in which we are active by incorporating the principles of sustainable development into all aspects of our engagement. Our framework of community engagement starts with need assessment and base line studies to understand the needs of the communities. The data is collected based on Participatory Rural Appraisal interviews with village heads, panchayat members, farmers, SHG members and the villagers at large. This feedback then is used to develop new programmes and improve existing programmes. We have a dedicated team of 107 functionaries including qualified professionals and subject matter specialists who are part of our corporate social responsibility team.

STATIC INFORMATIONRAJPURA DARIBA MINESMining Lease Area (in Ha)= 1142.20 Capacity: 0.90 Million tonnes per annum of Lead - Zinc Ore

Production: Production by underground mining Date of commencement of work: Capacity (Lead- Zinc Ore production): Date of commencement of production: April 1982 Capacity as on 31st March 2011 : 0.90 mtpa

DYNAMIC INFORMATIONRAJPURA DARIBA MINESGreenbelt:Year 2011-12 Total (as on date) Number of Plantation 0 1,19,850 Area under plantation (ha) 0 185.5 Acquired area (ha) 554.19

Quality of DischargeWater: Zero Discharge

CHAPTER 4

HEALTH, SAFETY AND ENVIRONMENTWe consider Health, Safety and Environment (HSE) to be the key element for our business and philosophy. We stay committed to continuous improvement in health, safety and environment in line with our HSE policy. All of our sites have a dedicated HSE team which work closely with operational teams and advices to our site management teams. We engage specialist consultants to ensure the best possible information and further improvement across all our operations. Management of contractor's safety, water & energy conservation, solid waste management and greenhouse gas emissions reduction is becoming an increasingly important focus at all of our operations. Not just because it is right to safeguard the health of the planet for future generations, but because it also makes sound and sustainable business sense. Our efforts are built around 3 pillars:y y y

Health: Eliminate occupational illness Safety: Provide a safe workplace Environment: Minimum harm to the environment by conserving natural resources through efficient use.

ENVIRONMENT SAFETYHindustan Zinc constantly reviews pollution control and environment safety controlling and monitoring systems at all its mining and smelting units. Dust emission control plants, tailing ponds for solid waste disposal and secure containments, water reclamation systems, effluent treatment plants, and gas cleaning treatment units, a forestation efforts, management of solid waste and much more to keep its operations eco-friendly.

AIR POLLUTIONCAUSE: y Dust is the major cause of air pollution. During ore mining, grinding in beneficiation plant , transportation of material through conveyors, lot of dust is produced. y This dust if inhaled by humans may cause respiratory problem for eg. (t.b., silicolosis). WAYS TO REDUCE DUST: y When ore is being fed to the Primary crusher , water sprinklers are used to suppress the dust. y Dust is also suppressed by spraying of certain specific chemicals. y The conveyors are covered by canopy. y Wet grinding is done. y Ventury and air scrubbers are used.

WATER POLLUTION CAUSE:y In the beneficiation plant various chemicals are added to slurry for separation of Zn and Pb. y Some of chemicals like NaCN, CuSO4 are highly toxic in nature. y These chemicals go to the tailing dam along with water. There percolation in y Ground water is very harmful for the nearby villages.