Galvanisation Plant

GALVANISATION PLANT

[EIRI/EDPR/3849] J.C.: 1958XL

INTRODUCTION

Galvanization is the process of applying a protective zinc coating to steel or iron in order to prevent it from rusting. The term is derived from the name of Italian scientist Luigi Galvani. Galvanized iron (GI) sheets are steel sheets which are basically coated with zinc and include a range of hot dip galvanized and electro-galvanized steel sheets. Zinc weathers at a very slow rate, so the coating generally has a long life. Zinc has a greater electro-negativity than iron and hence provides cathodic (or sacrificial) protection to the steel. This results in the zinc corroding in preference to the steel if the coating is chipped or damaged to expose the base metal. Besides acting as galvanic protector, The other functions of the zinc layer are as follow:

• To retain the steel intact with its full initial strength.

• To provide the surface a more pleasing appearance.

• To increase the life of any suitable organic finishing system applied over it.

• To protect the steel from corrosive attack in most atmospheres, acting as a continuous and lasting shield between steel and the atmosphere.

Process of Galvanizing

The process of galvanizing steel sheet was developed simultaneously in France and England in 1837.  Both of these methods employed a ‘hot dipping’ process to coat steel sheet with zinc.

Galvanizing is carried out on cold rolled sheets/cold rolled strips. Galvanizing process is broadly divided into hot dipping and electro-galvanizing. The hot dip process is more suitable for heavy coating weights, and electro-galvanizing for lighter coatings. For reasons of efficiency, galvanizing of cold rolled strip is more common than galvanizing of cold rolled sheets.

• Hot dip galvanizing – The principle of the process consists of the immersion of steel strips in molten zinc.  The zinc used for galvanizing is high grade with a zinc content of minimum of 99.95 %. After passing through the pretreatment tanks for degreasing, pickling, and cleansing, the strip passes through the annealing furnace and a pot containing molten zinc. The annealing furnace is used to apply the heat cycle needed to obtain the required mechanical properties and activate the surface with a reducing gas, which makes it easy to coat zinc on the strip surface. The coating weight is controlled by a purge gas jet blown on both surfaces of the strip from a nozzle above the pot, to remove excessive molten zinc. This process gives a relatively thick coating of zinc that freezes into a crystalline surface pattern known as spangles. During the process, a multiple layered structure of iron-zinc alloys is formed between the inner surface of the zinc coating and the steel strip.

• Electro-galvanizing – The principle of the process consists of immersion of steel sheet in an electrolyte, a solution of zinc sulfate or cyanide. Electrolytic action deposits a coating of pure zinc on the surface of the iron or steel.  The advantages of this process is that the thickness of the coating can be accurately controlled while the limitation of this process is that the thick coatings provided by the hot dip galvanizing process are not usually possible with this method.

A part of the GI steel production is corrugated to produce corrugated sheets (GC). Today the corrugation process is carried out using the process of roll forming. This modern process is highly automated to achieve high productivity and low labour costs. In the corrugation process sheets are pulled off huge rolls and through rolling dies that form the corrugation. After the sheets pass through the rollers it is automatically sheared off at a desired length. The standard shape of corrugated material is the round wavy style, but can be easily modified to a variety of shapes and sizes by simply changing the dies.

The cross section of a galvanized strip is composed of the steel substrate, iron-zinc alloy layers, and a zinc layer. Because the paint adhesion and weldability of the surface of this zinc layer are not necessarily good, galvannealing has been developed to improve these properties. In the basic process for galvannealed strip, the zinc-coated strip emerges from the pot and is heated in a galvannealing furnace, forming an iron-zinc alloy layer by the inter-diffusion of iron and zinc coating layer, so that the surface of the zinc layer also contains some amount of iron. The galvannealing line is usually equipped with a skin pass mill, a tension leveler, and chemical treatment equipment for chromating, following the galvannealing furnace.

GI sheets are produced both in annealed and full hard conditions.

COST ESTIMATION

Plant Capacity            4 MT/Day

Land & Building (2000 sq.mt.)    Rs. 1.47 Cr

Plant & Machinery                    Rs. 2.48 Cr

Working Capital for 1 Month    Rs. 17.73 Lac

Total Capital Investment          Rs. 4.37 Cr

Rate of Return                          22%

Break Even Point                      64%

CONTENTS

INTRODUCTION

PROCESS OF GALVANIZING

GI SHEETS SPECIFICATION

ADVANTAGES OF GALVANISING

USES AND APPLICATION OF GALVANISING

B.I.S. SPECIFICATION

PROCESS FLOW CHART

GALVANISING PROCESS

MANUFACTURING PROCESS OVERVIEW

THE GALVANIZING PROCESS CAN BE GROUPED TOGETHER UNDER THREE CATEGORIES, NAMELY

SOME OF THE COMMON TERMINOLOGIES USED IN GALVANIZING PROCESS ARE AS FOLLOWING:

ASH –

DROSS –

FLUX –

OVER-PICKLING –

INHIBITOR –

GALVANIZING BATH-

ALUMINUM ADDITIONS –

COATING THICKNESS

THE METALLURGICAL BOND

HOT DIP GALVANIZING PROCESS

ALL GALVANIZING CONSISTS OF FOUR FUNDAMENTAL STEPS:

1. SURFACE PREPARATION:

A. DEGREASING

B. CLEANING

C. PICKLING

D. AGITATION

E. RINSING

F. FLUXING

2. GALVANIZING:

A. IMMERSION

B. WITHDRAWAL

C. WATER QUENCHING

D. CENTRIFUGING

E. THREAD BRUSHING

3. POST TREATMENT:

4. STACKING:

5. INSPECTION:

CHARACTERISTICS OF GALVANIZED SURFACES

6. QUALITY CONTROL:

INSPECTION & TESTING

MARKET POSITION

CONSTRUCTION INDUSTRY TO LEAD THE GLOBAL GALVANIZED STEEL MARKET

GALVANISED STEEL MARKET

COASTAL INFRASTRUCTURE

AUTO SECTOR

THE RAILWAYS

ENERGY SECTOR

GALVANIZED STRUCTURE STEEL MARKET

GLOBAL GALVANIZED STRUCTURE STEEL MARKET COMPETITION BY TOP MANUFACTURERS

PRINCIPLES OF PLANT LAYOUT

PLANT LOCATION FACTORS

EXPLANATION OF TERMS USED IN THE PROJECT REPORT

PROJECT IMPLEMENTATION SCHEDULES

PLANT LAYOUT

MANUFACTURERS/SUPPLIERS OF GALVANISING SERVICES

SUPPLIERS OF RAW MATERIALS

SUPPLIERS OF ZINC INGOT

SUPPLIERS OF CASTIC SODA

SUPPLIERS OF HYDROCHLORIC ACID

SUPPLIERS OF PLANT AND MACHINERY

SUPPLIERS OF HOT DIP GALVANISING PLANT

SUPPLIERS OF DG SETS

SUPPLIERS OF EOT CRANE

SUPPLIERS OF POWER TRANSFORMERS

SUPPLIERS OF ELECTRICAL PANEL

SUPPLIERS OF ELECTRIC MOTOR

SUPPLIERS OF COOLING TOWER

SUPPLIERS OF EFFULENT TREATMENT PLANT (ETP PLANT)

SUPPLIERS OF AIR POLLUTION CONTROL EQUIPMENTS

SUPPLIERS OF AIR CONDITIONING EQUIPMENTS

SUPPLIERS OF AIR COMPRESSORS

SUPPLIERS OF PLATFORM WEIGHING MACHINE

SUPPLIERS OF MATERIAL HANDLING EQUIPMENTS

SUPPLIERS OF FIRE FIGHTING EQUIPMENTS

SUPPLIERS OF SHOT BLASTING MACHINE

SUPPLIERS OF JIGS AND FIXTURE

SUPPLIERS OF SUBMERSIBLE WATER PUMP

APPENDIX – A:

01. PLANT ECONOMICS

02. LAND & BUILDING

03. PLANT AND MACHINERY

04. OTHER FIXED ASSESTS

05. FIXED CAPITAL

06. RAW MATERIAL

07. SALARY AND WAGES

08. UTILITIES AND OVERHEADS

09. TOTAL WORKING CAPITAL

10. TOTAL CAPITAL INVESTMENT

11. COST OF PRODUCTION

12. TURN OVER/ANNUM

13. BREAK EVEN POINT

14. RESOURCES FOR FINANCE

15. INSTALMENT PAYABLE IN 5 YEARS

16. DEPRECIATION CHART FOR 5 YEARS

17. PROFIT ANALYSIS FOR 5 YEARS

18. PROJECTED BALANCE SHEET FOR (5 YEARS)