Nickel Refining
Nickel is a silvery-white metallic element found in the Earth’s crust. It is a hard, strong and corrosion resistant metal, not found in its pure form in nature. It is most commonly produced by refining and purifying laterite ore and is used to manufacture alloys and electroplating.
The refining process of nickel begins with the second processing step in nickel extraction. The Nickel ore is crushed in a ball mill and the mill discharge slurry is mixed with water to make a thick slurry. The slurry is then mixed with hot sulfuric acid and a precipitating agent such as calcium carbonate or calcium sulfate. The resulting reaction generates gaseous nickel sulfate, which is then condensed and precipitated.
The precipitated nickel sulfate is then filtered out of the mixture, and the solution is sent to a hydrometallurgical plant where it is reacted with hydrogen sulfide and air. This produces nickel matte, which is further processed by a smelting furnace to obtain nickel metal.
The smelting process involves reducing the nickel matte in a silica-based furnace in conditions of temperatures between 1600 and 1800℃ and pressures between 400-900 bars in the presence of a flux of silica and aluminum oxide. The furnace runs for about six hours and the end product is enriched nickel metal with a 99.5% purity.
The 99.5% pure nickel can then be further refined through an electrolytic process. This process involve running a current of electricity through a vat filled with purified nickel metal, and the current will extract the copper and other impurities, leaving behind 99.98% pure nickel.
The 99.98% pure nickel metal can then be rolled, drawn, and formed into various products. Nickel can be used to manufacture coins, corrosion-resistant alloys, electrical components, fabrics, and even processed food. It is also used in the electroplating industry to provide corrosion resistance, electrical conductivity, and a reflective finish.
Nickel refined through this process is of very high quality and is a valuable and versatile metal. It is used across many industries and applications. Nickel is a valuable metal and, due to its various applications, ensures a stable market and an active domestic industry.
