How to produce zinc oxide?

How to produce zinc oxide? Zinc oxide production methods generally have "fire" and "wet" two categories.

Fire Law "is divided into two kinds of indirect and direct methods. Direct method is the result of high temperature reduction, oxidation of zinc oxide products obtained directly. Indirect method based on high-purity zinc ingots as raw materials, high temperature sublimation, oxidation of zinc oxide this method has the advantage of high purity zinc drawback is expensive, energy consumption, high cost, product activity is low, use of surface is restricted.

"Wet", also known as Chemical Act, which more categories, but mostly in the development stage. Currently widely used method for the sulfuric acid method, namely crude ZnO leaching with sulfuric acid, cleaning, purification, adding sodium carbonate metathesis reaction, intermediate products obtained by drying or calcination that basic zinc carbonate or zinc oxide. As sulfuric acid method improvements, some ammonium bicarbonate instead of sodium carbonate as a precipitating agent. This method has the advantage of a process, you can get a variety of products, product quality is good, the drawback is sulfuric acid and sodium carbonate (ammonium bicarbonate) consumed in large, high production costs, equipment, serious corrosion byproduct sodium sulfate or ammonium sulfate difficult recovery; If not recycling, direct emissions cause environmental pollution.

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