Types of steel plants
There are basically two types of plants. The integrated steel plants, also known as ISPs and the mini steel plants, also known as MSPs. Raw materials are brought into each type of plant for processing. In the ISP plants, the raw materials are charged in a blast furnace. Hot air is pumped in to melt the iron and fluxes at 1600 Celsius. After having been molten together and cooled, the metal is known as pig iron. Further refining turns it into steel. Slag, which is a bi-product from manufacturing steel, is separated and blended with ?¢‚Ç¨Àúclinker?¢‚Ç¨‚Ñ¢ in order to make cement. The molten metal goes to the steel melting shop next, where it is further cleansed of impurities in an oxygen furnace. Next, the liquid steel is cast into semi finished products known as billets, blooms or slabs. This is a process known as continuous casting.
The raw materials
In the MSP plants, the raw materials are melted in an electric arc furnace. The furnace contains three rods and electric current is passed through them. This creates an arc that melts the metal. Induction furnaces are also used, though they are small and are being phased out. After melting, the molten metal is transferred to a ladle for refining. The metallurgy of the material as far as carbon, phosphorus, alloy, etc., is controlled during this stage of manufacturing. For example, the manufacture of stainless steel, requires specific amounts of nickel and chromium.
Another process used is rolling. The material is made into slabs and heated to 1200 Celsius. This makes the material malleable, which means it can be rolled into the finished products. The products from this type of treatment include bars, angles, structural parts, etc. Many of these products are created specifically for the construction industry. At this point, zinc can also be used to coat the product