The processes used in the refining of aluminium and zinc metals respec...
The processes used in the refining of aluminium and zinc metals are Hoope's process and fractional distillation.
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The processes used in the refining of aluminium and zinc metals respec...
The processes used in the refining of aluminium and zinc metals are:
1) Aluminium refining:
- Bayer process: This is the primary method used for refining aluminium. It involves treating bauxite ore with sodium hydroxide at high temperatures and pressures to dissolve aluminium oxide (alumina). The remaining impurities are filtered out, and the alumina solution is cooled and then seeded with pure alumina to promote crystallization. The resulting crystals are washed, dried, and heated to produce pure aluminium oxide, which can be further processed to obtain pure aluminium metal through electrolysis.
2) Zinc refining:
- Roasting: Zinc ores, such as zinc sulfide (sphalerite), are first roasted in air to convert them into zinc oxide. This process removes impurities and converts the zinc sulfide into zinc oxide.
- Leaching: The roasted zinc oxide is then leached with sulfuric acid to dissolve the zinc oxide and form a zinc sulfate solution.
- Purification: The zinc sulfate solution is purified using various methods, such as solvent extraction or electrolysis, to remove impurities like iron, cadmium, and lead.
- Electrolysis: The purified zinc sulfate solution is then subjected to electrolysis, where electrodes are immersed in the solution. Zinc metal is deposited on the cathode (negative electrode), while oxygen gas is evolved at the anode (positive electrode). The deposited zinc is periodically collected and further processed to obtain pure zinc metal.
These processes are essential in the refining of aluminium and zinc metals to obtain high purity materials that can be used in various industries and applications.