Zinc Presentation - Copy - Copy

8/4/2019 Zinc Presentation - Copy - Copy

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PRESENTATION ON

HINDUSTAN ZINC LIMITED

By Raman Shrivastava

Roll No-0802840058


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Introduction

Hindustan Zinc Limited (HZL) is an integrated mining andresources producer of zinc, lead, silver and cadmium. It is asubsidiary of Vedanta Resources PLC. HZL is the world'ssecond largest zinc producer. It's FY2011 revenues were Rs.108.91 billion

VisionBe the world's largest and most admired Zinc-Lead & Silvercompany.

Mission

Enhance stake holder's value through exploration, innovation,operational excellence and sustainability.

Be a globally lowest cost producer.

Maintain market leadership and customer delight.


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History

Hindustan Zinc Limited was incorporated from theerstwhile Metal Corporation of India on 10 January 1966 asa Public Sector Undertaking.

In April 2002, Sterlite Opportunities and Ventures Limited

(SOVL) made an open offer for acquisition of shares of thecompany; consequent to the disinvestment of Governmentof India's (GOI) stake of 26% including management controlto SOVL and acquired additional 20% of shares from public,pursuant to the SEBI Regulations 1997.

With the above additional acquisition, SOVL's stake in thecompany has gone up to 64.92%. Thus GOI's stake in thecompany now stands at 29.54%.


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Hindustan Zinc : Smelters

Debari Smelter

Vizag Smelter

Chanderiya Complex

Pyrometallurgical Lead ZincSmelter:

105,000 t Zinc35,000 t Lead120 t SilverHydrometallurgical ZincSmelter: 420,000 t ZincAusmeltTM Lead Smelter:50,000 t Lead851,000 t Sulphuric Acid

Captive Power Plant: 234 MW

Hydrometallurgical ZincSmelter:

Zinc 56,000 t

Sulphuric Acid 91,000 tpa

INDIA

22ndnd Largest Integrated Zinc Producer in the WorldLargest Integrated Zinc Producer in the World

Capacity Build-Up (t)

Product 2002 2007 2008 2010

Zinc 169,000 581,000 669,000 879,000

Lead 35,000 85,000 85,000 185,000

C.P.P -

(Coal Based)

234 MW 234 MW 474 MW

Hydrometallurgical ZincSmelter:

Zinc 88000 MT

Sulphuric Acid 419,000 tpa

Captive power29 MW


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Safety

Accidents is most unwanted interruption because ininvolves life and the main effects of accidents are :

Stopping of production

Human suffering

Loss of good skilled employees

Material loss

Demoralizing effect employees and society.

Legal proceeding

Harassment to management

Compensation.


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Safety precaution should be taken by Mechanical

Engg. Trainees at HZL are as follows :-

Always wear the protective helmet in plant

Do not wear the loose and nylon clothes.

Always wear rubber and strength shoes.

Do not roam in the plant without any supervision of instructor. Do not touch any machine or switching parts.

Always keep distance from fast moving machine.

Do not visit silver refinery and acid plant without any writtenpermission.

Always wear ear mask in plant because heavy machines produceshuge noise which is very harmful to ears.

Always wear mouth mask in plant because certain poisonous gageslike

CO, SO2, CO2 smoke dust etc. are very harmful for human health.


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Mines & Smelting Project of Hindustan Zinc

Limited in India

Mines

Rampura Agucha :230 kms north of Udaipur, Rajasthan,India

Sindesar Khurd:80 kms north-east of Udaipur, Rajasthan,

India Rajpura Dariba:76 kms north-east of Udaipur, Rajasthan,

India

Zawar: 40 kms south of Udaipur, Rajasthan, India

Smelter

Chanderiya :110 kms north of Udaipur, Rajasthan, India

Debari:13 kms north of Udaipur, Rajasthan, India

Vizag:Andhra Pradesh, India


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Zinc Products & Its Usages:-

First Use End-Use

Corrosion Protection(Galvanizing, Zinc Thermal

Spraying, Electro plating, )

Building/Construction, Energy/Power, Steel

Furniture, Agriculture, Automotive/Transport.

Brass (Copper-Zinc alloys) Aluminums alloys,Magnesium alloys

Building/Construction, Fittings Automotive andElectrical equipments.

Rolled Zinc Building/ Construction.

Batteries Automotive/Transport, Computers, Medical

Equipment, Construction products.

Zinc Compounds Food industry, Animal feed, Fertilizers,

Pharmaceutical industry, Cosmetics industry.

Zinc Oxide Paint pigments, Ceramic glazes Electrostatic

Copying Paper.


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Zinc Smelter Debari

Zinc Smelter Debari is a Hydrometallurgical zinc smeltersituated at Debari, about 13 kms from Udaipur, in

Rajasthan, India. The primary product of Debari is HighGrade (HG) zinc and it also recovers cadmium as by-product

Zinc Smelter Debari was commissioned in the year 1968with an initial production capacity of 18,000 tonnes perannum of zinc. In the past several years the capacity of the

smelter has been expanded five folds to its currentproduction capacity of 88,000 tonnes per annum of zinc.


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Hydro Metallurgical Process Description: -

Hydro metallurgical zinc extraction process is

conventionally known as Roast-Leach-Electro

win process which can broadly be divided into

following processes.

Roasting

Leaching and Purification

Cell House


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Roasting:-

The roasting of a concentrate is a process which precedes smelting inhydro metallurgy and leaching in hydro metallurgy. An oxide is moreeasily reduced to the metal than a sulphide, and leaching becomeseasier if the metals were present as sulphate, chloride or oxide. Theobjective of the roasting process is to convert zinc sulphide to acid

soluble zinc oxide and sulphur dioxide gas, utilising the followingreaction:

2 ZnS + 3O2 = 2ZnO + 2SO2The solid zinc oxide (ZnO, Calcine) is separated from the gaseous

sulphur dioxide (SO2) utilising various techniques. The collected zinc

oxide is sent to the Leaching Plant and the sulphur dioxide goes tothe Sulphuric Acid Plant via the gas cleaning plant.


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Roaster Plant


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Leaching: -

Leaching is a widely used extractive metallurgy technique, whichconverts metals into soluble salts in aqueous media.The calcine isfirst leached in a neutral or slightly acidic solution (of sulfuric acid)in order to leach the zinc out of the zinc oxide. The remainingcalcine is then leached in strong sulfuric acid to leach the rest of the

zinc out of the zinc oxide and zinc ferrite.The result of this process is a solid and a liquid; the liquid contains thezinc and is often called leach product; the solid is called leachresidue and contains precious metals (usually lead and silver) whichare sold as a by-product. There is also iron in the leach productfrom the strong acid leach, which is removed in an intermediate

step, in the form of goethite, jarosite, and haematite. There is stillcadmium, copper, arsenic, antimony, cobalt, germanium, nickel,and thallium in the leach product. Therefore it needs to be purified.


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There are a variety of leaching processes, usually classified by the types of

reagents used in the operation. The reagents required depend on the ores

or pretreated material to be processed. A typical feed for leaching is either

oxide or sulfide.

Leaching process in hydro metallurgical extraction of zinc metal consists of

following major steps:-

Neutral Leaching

Weak Acid Leaching

Hot Acid Leaching Strong Acid Leaching

Pre neutralization

Lead-Silver residue Filtration

Jarosite Precipitation & Filtration

Jarofix Production

Magnesium Removal

Purification of Solution

Copper-Cadmium Recovery


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Purification:-

In the neutral leaching process along with zinc oxide, all othermetal oxides also get leached in metal sulphates. These metalsulphates are more than the tolerable limits, which are copper,cadmium, cobalt, nickel. All these impurities are removed by zincdust cementation process in the purification section.

The basic reaction is that of electrolytic reduction of those metals,whose positions in the electromotive series for sulphate are belowthat of zinc:

CuSO4+Zn

o

ZnSO4+Cu

o

CdSO4+Zno ZnSO4+Cd

o

CoSO4+Zno ZnSO4+Co

o

Fl P


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Flow Process


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Zinc Electrolysis Plant

Electrometallurgy: - Electrometallurgy includes all metallurgical processes whichutilize electricity and electrical effects. The various electrometallurgical processesare electro winning, electro refining and electro deposition.

Electro winning process: - The process by which metals is extracted from electrolyte,whether it is aqueous or fused salt is termed as 'electro winning'. The electrolyte

is an aqueous medium for the recovery of metals like Zn, Sb, Cu, Cr, Ga, Mn, etc.,while it is a molten salt in case of reactive metals like Na, K, Al, Mg etc.

The main factors influencing the electro winning of metal are:

Current density

Temperature

Composition of electrolyte

Addition agents Influence of impurity ions in the metal deposition

Hydrogen over voltage.


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Zinc Electrolysis plant consists of the

following sections:-

Gypsum removal section

Electrolyte storage and circulation system with

cooling towers

Cell House

Cathode stripping

Anode washing and cell cleaning

Reagent preparation and addition


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Salient features of the cell house at ZSD

No of cells

Cell Volume

No of anodes in each cell

No of cathodes in each cell

Effective cathode area:

Nominal current density:

Stripping machines

Stripping cycle:

Rectifier for DC

AC to DC conversion eff.

Power consumption/ MT

cathode

Cathode productionStrontium Carbonate addition

Gum Arabic

Anode cleaning cycle

Cell cleaning Cycle

No of neutral coolers

No of spent coolers

124

35 m3

115

114

3.5

400-480A/m

2 Nos

48 h

2*95 KAmp (190 Kamp Max.)

98.5 %

2995 DC kWh (3041 AC kWh)

521 MT/Day2-4 Kg/MT Cathode

94-110 gm/MT Cathode

30 Days

60 Days

3

12


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Zinc Melting & Casting Plant:-

No of Furnaces

Type of furnaces

Make

No of Inductors in each furnace

Rating of each inductorMelting rate each furnace

No of charging Columns in each furnace

Molten metal holding capacity

Temperature range

Slab casting capacity

Jumbo casting capacityTotal production capacity

2

Water cooled induction furnace

AJAX-TOCCO

4

600 Kwh22 MT/hr

2

100MT

500-525oC

273MT/Day

273MT/Day546MT/Day


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Conclusion

It was a great experience to be there in HZL, Debari for my practical training.Like every good thing, it had to come to an end and so it did. Though i amfeeling sad at this point of time while leaving from here but i do have thegreat memories of time spent here.

During these days, i certainly learnt a lot about every aspect of thisfield, right from the working environment and people management to the

technical details of various equipment and process. Really i knew here thatonly theoretical knowledge is not sufficient. I should have pragmaticapproach while dealing in industries. Good communication and sincerityare the most important things in industries. By these two factors you canimpress your seniors and colleagues.

The things are numerous, while words are only few. To conclude, I

would rather say that even after my full try, i could pick up only a mouthfulof knowledge out of sea. The time was really very less while there was alot to learn.

Well, thats how life goes on. I hope I would have another chance tovisit and learn more from it.


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Thank You

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Zinc Presentation - Copy - Copy