1. HINDUSTAN ZINC LIMITED:Hindustan Zinc Ltd (HZL) is Indias
leading zinc producer. A vertically integrated Mining &
Smelting company, HZL, is currently gearing up to becoming a global
lowest-cost producer. As a part of Vedanta Resources, a London
listed metals and mining major with Aluminium. Copper and Zinc
operations in UK. India and Australia. HZL takes advantage of its
mineral resources and related core competencies and believes it has
growth opportunities for increasing products and improving
returns.
The Key features of the company are as: The only integrated Zinc
producer in India Refined Zinc production capacity 411,000 tpa
Refined Lead production capacity 85,000 tpa Ore treatment capacity
5.85 Mtpa
1.1 INTRODUCTION:Hindustan Zinc Limited was incorporated as a
Government of India Enterprise under the ministry of Steel &
Mines, Department of Mines, on January 10, 1966, after take-over of
erstwhile Metal Corporation of India Limited, interalia, to own,
manage& develop mining & smelting capacities for the
important strategic zinc & Lead metals in the country with an
operative lead smelter at Tundoo, Dhanbad & Mines at Zawar,
Udaipur. Phasewise development of mines, commissioning of Smelters
at Debari & Vishakhapatnam, capacity of HZL to produce lead
& zinc reached to 79,000 MT of zinc & 30,000 MT of lead by
1990
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HINDUSTAN ZINC LIMITED 1.2 VISION:Be a world-class zinc company,
creating value, leveraging mineral resources and related core
competencies.
1.3 MISSION: Be a lowest cost Zinc Producer on a global scale,
maintaining market leadership Produce half Million Tonnes/Year of
Zinc by 2005 Be innovative, customer oriented and eco-friendly,
maximizing stake-holder value The only integrated Zinc producer in
India Refined Zinc production capacity 230,000 tpa Refined Lead
production capacity 35,000 tpa Ore treatment capacity 4.6 Mtpa
Continuous operational improvements, meticulous planning,
constant innovation, extensive R&D, technological upgradation
and so much more - HZL has come a long way and grown into a
multi-unit and multi-product company.
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1.4 HISTORY:Hindustan Zinc Ltd, was created from the erstwhile
metal Corporation of India (MCI) on 10th January 1966 as a Public
Sector Undertaking. In April 2002, the Government of India.
disinvested its majority stake in HZL, and it became a part of the
fast growing Sterlite group, Since then HZL as been growing from
strength to strength HZL produces Zinc, Lead and other by-products
including Sulphuric Acid, Silver and Cadmium. HZL achieved an
all-time high with a record output of 2,61,226 tonnes Zinc and
6,14,938 tonnes of record production of Zinc concentrate during
2003-04. Today HZL is Indias leading base metal producer. HZL is a
vertically intergrated Mining & Smelting company, gearing up
to: Harnessing mining resources to help India achieve
self-sufficiency in Zinc. Become a global leader in Zinc. Create
value for all entities whether it is Customers, Investors or
Employees.
Constant innovation, meticulous attention to detail, extensive
investments in R&D and technology are the hallmarks of HZL
making it a multi-unit and multi-product company.
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HZL Milestones at a glance:2002-03 Sterlite acquires 26% and
management control in HZL from the Government of India in
privatization. A further 20% is bought from market through open
offer and 18.92% from Government of India under call option. 1991
Chanderiya Pyrometallurgical lead-zinc smelter and Rampura Agucha
mine begin production. 1983 1977 1971 1968 Rajpura Dariba Mine
starts production. Vizag zinc smelter and second set of Zawar mine
facilities commissioned. First expansion of Zawar mine
commissioned. Debari smelter commissioned.
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2.1 PHYSICAL AND CHEMICAL PROPERTIES OF ZINC:
Atomic number Atomic mass Electronegativity according to Pauling
Density Melting point Boiling point Vanderwaals radius Ionic radius
Isotopes Electronic shell Energy of first ionisation Energy of
second ionisation Standard potential Discovered
30 65.37 g.mol -1 1.6 7.11 g.cm-3 at 20C 420 C 907 C 0.138 nm
0.074 nm (+2) 10 [ Ar ] 3d10 4s2 904.5 kJ.mol -1 1723 kJ.mol -1 -
0.763 V Andreas Marggraf in 1746
Zinc is a lustrous bluish-white metal. It is found in group IIb
of the periodic table. It is brittle and crystalline at ordinary
temperatures, but it becomes ductile and malleable when heated
between 110C and 150C. It is a fairly reactive metal that will
combine with oxygen and other nonmetals, and will react with dilute
acids to release hydrogen.
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2.2 PHYSICAL AND CHEMICAL PROPERTIES OF LEAD:
Atomic number Atomic mass Electronegativity according to Pauling
Density Melting point Boiling point Vanderwaals radius Ionic radius
Isotopes Electronic shell Energy of first ionisation Energy of
second ionisation Energy of third ionisation Energy of fourth
ionisation Energy of fifth ionisation Discovered by
82 207.2 g.mol -1 1.8 11.34 g.cm-3 at 20C 327 C 1755 C 0.154 nm
0.132 nm (+2) ; 0.084 nm (+4) 13 [ Xe ] 4f14 5d10 6s2 6p2 715.4
kJ.mol -1 1450.0 kJ.mol -13080.7 kJ.mol -1 4082.3 kJ.mol -1 6608
kJ.mol -1 The ancients
Lead is a bluish-white lustrous metal. It is very soft, highly
malleable, ductile, and a relatively poor conductor of electricity.
It is very resistant to corrosion but tarnishes upon exposure to
air. Lead isotopes are the end products of each of the three series
of naturally occurring radioactive elements.
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3.1 USES OF ZINC:Zinc is the fourth most common metal in use,
trailing only iron, aluminium, and copper in annual production
Zinc is used to galvanize steel to prevent corrosion Zinc is
used to Parkerize steel to prevent rust and corrosion Zinc is used
in alloys such as brass, nickelled silver, typewriter metal,
various soldering formulas and German silver
Zinc is the primary metal used in making American cents since
1982 Zinc is used in die casting notably in the automobile industry
Zinc is used as part of the containers of batteries. The most
widespread such use is as the anode in alkaline batteries
Zinc is used as the anode or fuel of the zinc-air battery/fuel
cell providing the basis of the theorised zinc economy
Zinc is used as a sacrificial anode on boats and ships that use
cathodic protection to prevent corrosion of metals that are exposed
to sea water
Zinc is used in contemporary pipe organ building as a substitute
for the classic lead/tin alloy in pipes sounding the lowest (pedal)
tones, as it is tonally almost indistinguishable from lead/tin at
those pitches, and has the added advantages of being much more
economical and lighter in weight. Even the best organ builders use
zinc in this capacity.
Zinc oxide is used as a white pigment in watercolours or paints,
and as an activator in the rubber industry. As an over-the-counter
ointment, it is applied as a thin coating on the exposed skin of
the face or nose to prevent dehydration of the area of skin. It can
protect against sunburn in the summer and windburn in the winter.
Applied thinly to a baby's 7
diaper area (perineum) with each diaper change, it can protect
against rash. As determined in the Age-Related Eye Disease Study,
it is part of an effective treatment for age-related macular
degeneration in some cases
Zinc chloride is used as a deodorant and can also be used as a
wood preservative Zinc sulfide is used in luminescent pigments such
as on the hands of clocks and other items that glow in the
dark.
Zinc methyl (Zn(CH3)2) is used in a number of organic syntheses.
Zinc stearate is a lubricative plastic additive. Lotions made of
calamine, a mix of Zn-(hydroxy-)carbonates and silicates, are used
to treat skin rash.
Zinc metal is included in most single tablet over-the-counter
daily vitamin and mineral supplements. It is believed to possess
anti-oxidant properties, which protect against premature aging of
the skin and muscles of the body. In larger amounts, taken as zinc
alone in other proprietaries, it is believed by some to speed up
the healing process after an injury. Preparations include zinc
acetate and zinc gluconate.
Zinc gluconate glycine and zinc acetate are also used in throat
lozenges or tablets to reduce the duration and the severity of cold
symptoms.
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3.2 USES OF LEAD:The following uses for lead are gathered from a
number of sources as well as from anecdotal comments. I'd be
delighted to receive corrections as well as additional referenced
uses (please use the feedback mechanism to add uses).
the metal and the dioxide are used in storage batteries cable
covering, plumbing, ammunition manufacture of PbEt4 - an antiknock
compound in petrol. Environmental concern with lead poisoning, (and
cheaper unleaded petrol prices) is slowly resulting in less use of
lead in petrol
the metal is very effective as a sound absorber a radiation
shield around X-ray equipment and nuclear reactors used extensively
in paints, although recently the use of lead in paints has been
drastically curtailed to eliminate or reduce health hazards the
oxide is used in producing fine "crystal glass" and "flint glass"
with a high refractive index for achromatic lenses solder used by
the Romans for plumbing (the decline of the Roman empire is
attributed to lead in the water supply!) used to contain corrosive
liquids alloying cable covering ammunition shield against X-rays
oxide used to produce crystal glass insecticides
4. UNITS:9
4.1 Mines in Operation:
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4.1.1. Zawar Group of Mines:Zawar group of mines (Mochia,
Balaria, Zawar Mala & Baroi) is situated in the Girwa Tehsil of
Udaipur District of Rajasthan at a distance of about 35 kms from
Udaipur, amidst a valley of Arawali hills.
4.1.2. Rajpura-Dariba Mines:The multi=-metal Rajpura-Dariba
Mines, which is located about 85km away from Udaipur (Raj.) has
demonstrated ore reserve of about 16.4 million tones having metal
content of about 6.9% zinc & 2.2% lead.
4.1.3. Maton Rock Phosphate Mine (Udaipur):Maton mine has been
developed to meet rock-phosphate requirements for the
super-phosphate & phosphoric acid plant at Debari.
4.4.4. Rampura Agucha Mining Complex:The prestigious Rampura
Agucha Open Cast Mining Complex is Asias richest & largest lead
zinc deposit.. It is situated in Tehsil Hurda, District Bhilwara in
Raj. The discovery of a world class diposie of 60.6 million tones
at Rampura Agucha, containing 15.4% metal has dramatically altered
the prospect of not only reducing the cost of production of zinc
and lead, but also the expansion of HZLs production capacity
resilting in increasing the demand satisfaction upto 82% for zinc
and 61% for lead.
4.1.5. Sargipali Mine (Orissa) 4.1.6. Agnigundala Lead Mine
(Guntur, A.P.)
4.2 Smelters in Operation :11
1. Debari Zinc Smelter, Distt. Udaipur (Raj.) 2. Vizag Zinc-Lead
Smelter (A.P) 3. Tundoo Lead Smelter (Dhanbad), Bihar 4. Chanderiya
Lead-Zinc Smelter
5. CHANDERIYA LEAD ZINC SMELTER
Date of commencent Date of completion
17.11.88 16.05.91
Situated in Chittorgarh District of Rajasthan, the Chanderiya
Lead-Zinc smelter is around 8 kms north of Chittorgarh town on the
state highway. This gigantic super smelter is integrated with
Ramura Agucha Mines at a cost of Rs. 617 crore. The Chanderiya
Smelter treating Lead-zinc concentrates is based on the Imperial
Smelting Process route adopting blast furnace technology for
simultaneous production of lead and zinc metal. The Indian
installation is the 14th furnace being in U.K., Australia, Zambia,
Japan, Germany, France, Italy, Yugoslavia, Romania, Poland and
China.
5.1 PRODUCTION:12
New facilities have been built at Chanderiya which will take
total zinc output to some 400,000 tpa. This is being accompanied by
a new 50,000 tpa lead smelter, giving lead capacity of 85,000 tpa,
which is due for commissioning by March 2006. The output at Rampura
Agucha lead-zinc mine has been expanded to 3.3 mtpa, and eventually
3.75 mtpa, to feed the new smelting capacity. A 154 mw coal fired
power plan has been competed which will provide power for both the
new and existing facilities. The expansion projects were
commissioned ahead of schedule in May 2005 and the total cost was
15% below the estimated budget of $425m
5.2 PRODUCTION CAPACITIES
PRODUCTS REFINED ZINC REFINED LEAD SULPHURIC ACID SILVER COPPER
CATHODE/SULPHATE CADMIUM
CAPACITY ( TPA) 70000 35000 176000 74 2100 375
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5.3 AIMS OF AN INDUSTRY
a) b) c) d) e) f) g)
To produce goods To have continuous production To produce goods
at low cost To produce goods of higher quality Have long life of
equipment Social heritage Economic growth
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6. SINTER PLANTHZLs CLZS zinc and lead production begins with
zinc and lead concentrates wherein zinc and lead are present as
sulphides is imported from its own captive mines in India.
Concentrates is received in trucks and stored inn a Raw Material
House. From the Raw Material House, it is transported to Bins in
Sinter Plant by a well controlled belt conveyor system, where along
with certain other necessary ingredients like fluxes, secondary
materials and water it is mixed in a prefixed proportion and fed to
sintering machine. Sintering serves the dual purpose of converting
the sulphides into oxides and agglomerates the product into porous,
high strength lumps called sinter. In the sintering process the
sulphides of lead and zinc react with oxygen of air to form SO2
gas: 2 ZnS + 3 O2 2ZnO + 2 SO2 2 PbS + 3 O2 2 PbO + 2 SO2 The
sinter plant has following main sections: 1. 2. 3. 4. 5. 6. Raw
Material Handling Plant (RMH) Charge Proportioning and Conditioning
System Sinter Machine Sinter and Return Fines Handling (Crusher
Plant) Gas Cleaning (Acid Plant) Slurry Handling
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6.1 RAW MATERIAL STOCK YARD AND UNLOADING STATION:Concentrate
and fluxes are delivered by truck and unloaded into the unloading
hoppers. The raw material is transported to a tripper belt conveyer
which distributes the raw material to individual boxes of the raw
material stockyard. Storage capacity of the stockyard is as
follows: Zinc concentrate-Rampura agucha mines-6250 tonnes.
Zinc concentrate-Ambamata mines-1600 tonnes. Zinc
concentrate-Rajpura dariba mines-1600 tonnes. Bulk
concentrate-Ambamata-3500 tonnes. Lead concentrate-Rampura agucha
mines-2500 tonnes. Lead concentrate-Rajpura dariba
mines-2500tonnes. Lead concentrate-Zewar mines-2500 tonnes. Lime
stones flux-450tonnes. Iron flux-700 tonnes.On an average the
composition of the raw material from mines from mines is as
follows; The composition of Zinc concentrate is Zn 50-55%, S
30-32%, Pb 2-5% The composition of Lead concentrate is Pb 40-55%, S
16-18%, Zn 1.-2%.
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6.2 CHARGE PROPORTIONATE AND CONDITIONING SYSTEMThe material is
then carried to the charge proportionate and conditioning system by
a series of conveyer system (tray conveyer). The raw materials,
when it is oversized, is passed through a disintegrator. There are
15 storage bins of capacity 50 cu. Metre as: 6 for Zn cone.; 3 for
Pb cone.; 1 for bulk cone.; 1 for iron flux; 2 for lime stones and
2 for return fines which are of 25 cu. Metre capacity. All bins are
equipped with vibrators and shock cannons to prevent blockage.
Moisture addition is done in a controlled way at mixing and
conditioning drums, so as to get a moisture content of 6% in the
feed to the sinter machine. All the various sources of inputs are
controlled through weigh feeders located at the bottom of the
proportioning bins.
6.3 SINTER MACHINE:The updraft sinter machine has an area of 120
sq. mts. And 109 pallets each measuring 3m x 1m in size. There are
444 grate bars in a pallet. The ore concentrate is reduces to size
of 6mm by the hammer mill. After reducing the size, the ore
concentrate is sent to the bins. In the bins the ore concentrate
and the return fines are added in the ratio 3:1. Above the sinter
machine, the main and the ignition layer bins are located. The
ignition layer thickness is generally adjusted to give 30 mm height
and the total layer max. height is 400 mm. The ignition layer is
fired by 2 burners operating on light diesel oil (LDO), to get
about 1000.C hood temp. After proper burning of the ignition layer
the main layer is made and air is blown from down through the pump
and then the main layer is burnt. 1. 2. Ignition Layer (10% to 15%)
Main Layer (85% to 90%)
Here the main reaction are ZnS + O2 => ZnO + SO2 PbS + O2
=> PbO + SO2 The SO2 is sent to the gas cleaning plant. 17
The big lump of PbO and ZnO is not suitable for the ISF plant.
So it is necessary to reduce the size of the lump. For this purpose
sinter breaker is located after the sinter machine, this breaker
reduce the size of the lump upto 200mm. But this size too is not
suitable so they are then sent to the spike roll crusher. These
crusher reduce the size of lump to 65 to 130mm. These are then sent
to the classifier which separate the lump size from 65-130mm from
the rest. Then the suitable part is sent to the ISF Plant if it is
in working condition otherwise it is sent to the storage yard by
tray conveyer system. The lump of size below 65mm at temp 600-800.C
is sent to the corrugated roll crusher, This crusher reduce the
size to 35mm, then it is sent to the smooth roll crusher to reduce
its size to 6-8 mm which is used as fines in sinter plant. These
fines have high temp. so they are sent to the cooling drum. After
passing through 7 The drum the temp of the fines is reduced to 90.C
and then they are sent to the return fines bin. Anywhere where dust
is formed, dust sucker are located. These dust sucker suck the dust
and sent it to the bag filter. Bag filter collect the dust. The
ignition gases are drawn by the ignition waste gas fan through wind
box and conveyed to recirculating gas plant. Dust and spillage are
removed in a solid separator from the sinter hood. The rich SO2 gas
is drawn and sent to the wet gas cleaning plant through HGP (hot
gas precipitator) with the help of booster blower. Beside the
ignition fan, 4 fresh air fans and 1 recirculating fan is also
there to supply fresh air and to recirculate air to 17 wind boxes
of the sinter machine. There are 5 cyclones for dust removal of the
ventilation air and recirculating gases in order to avoid any dust
build up in the ducts and also to avoid wear of fans. The
composition of the sinter product is: Zn 40-44% Pb 18-20% FeO
10-10.5% S less than 1% CaO 4.5-5% SiO2 3.5-4% Ratio of CaO:SiO2
1.2
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The composition of sinter fines is: Zn 42.50% Pb19.50% FeO 10.3%
S 2.14% CaO 4.6% SiO2 3.7%
The specifications of the plant are as follows:Effective
updrafts are of the sinter machine Width of the pallet Capacity
(Dry basis) Sinter material Specific Sulphur burning rate Sinter
Production Sulphur content of mixture SO2 content of the gases
Moisture Content Bulk density of the crude charge : : : : : : : : :
120M2 3.0m 4600 tons per day 1.6tons per square meter per day 1080
tons per day 5%