A Report On Summer A Report On Summer

TrainingTraining

Undertaken atHindustan Zinc Limited, Debari

CONTENTSCONTENTS About the Company History of the Company Sections in HZL Power requirement Organizational Chart Basic Processes Done Mining Roasting Leaching Zinc Electrolysis Melting & Ingots Formation Zinc & Its Uses Project- SWITCHYARD

Zinc Smelter Debari is a Hydrometallurgical zinc smelter situated at Debari, about 13 kms from Udaipur, in Rajasthan, India. The primary product of Debari is High Grade (HG) zinc and it also recovers cadmium and Sulphuric Acid as by-product.

Zinc Smelter Debari was commissioned in the year 1968 with an initial production capacity of 18,000 tonnes per annum of zinc. In the past several years the capacity of the smelter has been expanded five folds to its current production capacity of 88,000 tonnes per annum of zinc.

The plant has three roasting section, one leaching & purification section, one electrolysis & one melting & casting sections.

Sections in Sections in HZLHZL

Zinc Smelter Debari also has 14.81 MW captive power plants to supply the power requirements for its metallurgical operations; it also sources additional power requirements from ourcaptive thermal power plants located at Chanderiya and at Zawar.

Power RequirementPower Requirement

Raw Material Supplies:- (a). Zawar Mines

(b). Agucha Mines

(c). Rajpura Dariba

Mines

(d). Sindesar Khurd

All in Rajasthan as shown in the map above: -

Product

Buyers:-

(a). Tata

(b). Bhel

(c). Steel

Companies

Power Consumption: - 50 to 52 MW per day.

Note: - Zinc produced is 99.995% pure.

Mining is the process of extracting valuable minerals or other geological materials from the earth, usually from an ore body, vein or seam. Materials recovered by mining include metals like Zn, Fe & coal, Diamond etc.

MiningMining

• Above shown is Rampura Agucha mines.

Roasting is a process of oxidizing zinc sulfide concentrates at high temperatures into an impure zinc oxide, called "Zinc Calcine".

Roasting ProcessRoasting Process

• Above shown is Debari Roaster Plant.

The chemical reactions taking place during the process are: -

2ZnS + 3O2 → 2ZnO + 2SO2

SO2 so produced is at first converted to SO3 then it is sent to acid plant where it is converted to Sulphuric acid.

2SO2 + O2 → 2SO3

Reactions taking placeReactions taking place

Leaching is the process of converting Zinc Oxide (Calcine) to Zinc Sulphate Solution i.e., ZnO to ZnSO4.According to the reaction as shown: - ZnO + SO3 ZnSO4

Leaching ProcessLeaching Process

• Above is external view of Leaching Plant

Electrolysis of ZnSO4 solution takes place in electrolysis cells with Al as cathode & Pb as anode.  

Zinc ElectrolysisZinc Electrolysis

The reaction can be represented as: - ZnSO4→ Zn2+ + SO4

2-

SO4 + H2O→ H2SO4 + ½O2

Zn ions migrate towards the cathode and get deposited in form of sheets and rest of the ions get deposited at anode in the form of oxides like MnO2.

Reactions Taking PlaceReactions Taking Place

Melting And Ingots FormationMelting And Ingots FormationZinc cathodes are melted in induction furnaces & cast into marketable products such as ingots.

Other metals & alloy components may be added to produce zinc containing alloys used in die-casting or general galvanization applications.

Zinc & Its UsesZinc & Its UsesZinc metal is used in a number of applications including: -

Galvanizing Die- Casting Alloy Forman

Zinc-Oxide Rolled Zinc

SWITCHYARDSWITCHYARD

Project OnProject On

HZL, DebariHZL, Debari

CONTENTSCONTENTS Intro to Switchyard Switchyard Equipments Power Transformer Circuit Breaker Current Transformer Potential Transformer Isolator (Disconnector) Lightning Arrester

The term switchyard, used in association with the electric power system, or grid, refers to the combination of electrical disconnects, fuses and/or circuit breakers used to isolate electrical equipment.

SWITCHYARDSWITCHYARD

Switchyard EquipmentsSwitchyard Equipments Power Transformers Circuit Breaker Current Transformer Potential Transformer Isolators Lightening Arrester

• A brief detail of each equipment is as below:

Power TransformersPower Transformers

A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors-the transformer's coils. There are four transformer in the switchyard:

2(Bhel): - Ratings 30 MVA

2(Kirloskar): - Ratings 25MVA

Circuit BreakersCircuit Breakers

Two types of Circuit Breakers are used in the switchyard :

a). Oil Circuit Breakerb). Sulfur Hexafluoride(SF6) Circuit Breaker

Description About CBsDescription About CBsA circuit breaker is an automatically operatedelectrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect fault condition, by interrupting continuity, and to immediately discontinue electrical flow.

We are going to discuss about: Oil circuit breaker & SF6 circuit breaker

Oil Circuit Breakers are used to switch circuits and equipment in and out of a system in a substation. They are oil filled to provide cooling and to prevent arcing when the switch is activated

SF6 circuit breakers operate to switch electric circuits and equipment in and out of the system. These circuit breakers are filled with compressed sulfur-hexafluoride gas which acts to open and close the switch contacts. The gas also interrupts the current flow when the contacts are open. 

Oil Ckt. Breaker

SF6 Ckt. Breaker

A current transformer (CT) is used for measurement of electric currents. When current in a circuit is too high to directly apply to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments and thus the current is measured.

Current TransformerCurrent Transformer

Potential TransformerPotential TransformerA Potential Transformer (PT) steps down voltage of a circuit to a low value that canbe effectively and safely used for operation of instruments such as ammeters, voltmeters, wattmeters, and relays used for various protective purposes. Basically it is designed monitoring single-phase and three-phase power line voltages in power metering applications.

Isolator are outdoor 3-phase high voltage equipment. They are used to change over power circuit and electrically isolate the equipment under no-load condition. It is used to make sure that an electrical circuit can be completely de-energized for service or maintenance.

IsolatorsIsolators

Lightning ArresterLightning ArresterLightning Arrester are protective devices for limiting surge voltages due to lightning strikes or equipment faults or other events, to prevent damage to equipment and disruption of service. Also called surge arresters. These are installed on many different pieces of equipment such as power poles, power transformers, circuit breakers, bus structures, & in substations