How to Prepare Liquid Metal Alloys

Metal ores must be liquidified to form into alloys.

Steel and cast iron are actually iron and carbon alloys, since carbon is added to iron to form both. When forming metal alloys, manufacturers must turn them into liquid to pour into a mold, where they then cool and harden into the needed form. Alloys are metals smelted together in a way that prevents them from being separated, except by melting. Manufacturers smelt different alloys together to create metals with certain properties. For example, they add nickel to steel, to make it more resistant to corrosion.

Instructions

1. Process the ores required to make the alloys for your specific application. The stone that contains the iron ore should be crushed, mixed with water and then turned into slurry. Specialized surfactants are then added, which cause either the impurities or the ore to float to the surface.

2. Feed iron ore, limestone and coke to the blast furnace. The coke burns to form carbon dioxide in a process that produces a very high heat. The limestone ensures the rocky material in the ore turns into slag. The ore will not melt on its own.

3. Keep heating the metal using the blast furnace until the temperature has reached 3,000 degrees Fahrenheit -- the temperature needed to mix the different metals together in a preheated ladle, where the metal is transferred to the pouring lines. At the pouring lines, the different metals are combined to form the alloys.

4. Take regular samples of the molten metal, to check the composition. Use a spectrometer to determine what alloys should be added, to bring the metal to the specification required by the customer. The spectrometer measures the amount of light that passes through a particular medium. The amount of light absorbed by a medium is proportional to the amount of the absorbing material in the solution.

Tips & Warnings

• Cast iron is ideal for castings, because it is runny -- easily flowing into the mold. In addition, the cast iron does not shrink much, making it more reliable.

• Sulfide ores should be roasted to remove sulfur. The oxygen in the air and the sulfur combines to form sulfur dioxide gas.

• High temperatures are required to melt metal, with temperatures of 2,750 degrees Fahrenheit needed to melt iron. The furnace releases hot waste gases, which are circulated down to the bottom to continually heat the furnace. These high temperatures can cause health problems for those nearby, and can even cause injury or death.

References

• Eurometaux: What Are Alloys?
• Caveman Chemistry: Metals
• Southwest Steel Casting Company: Melting Steel
• Chemguide: Iron and Steel
• University of Cincinatti; Spectrophotometer Use; David B. Fankhauser; July 2007