Aluminum hydroxide produced?

aluminum hydroxide, is both weak acid and weak base, have a wide range of applications in the industry, can be used as fire retardant agents, lubricants, etc. , but how aluminum hydroxide is prepared, you know? Let us know.

in the industry now has two kinds of method of making aluminum hydroxide, lime bayer process and alkali sintering process. A bayer process

bayer process after so many years of development, a lot of changes have taken place in the preparation process, but does not change its principle. The principle of bayer process is implemented using different temperature of reaction direction:

on type, for example, under the condition of high temperature, on a mixture of alumina in sodium hydroxide solution, get the sodium aluminate solution, while iron, silicon and other impurities not soluble in sodium hydroxide solution, after the separation, cooling, make the type to carry on the back reaction, aluminum hydroxide and sodium hydroxide mother liquor, and sodium hydroxide mother liquor can be the next round of production. Preparation of alumina industry in general, in this way, will be of aluminum hydroxide roasting dehydration.

two alkali lime sintering,

it is bauxite and limestone soda-lime sintering in high temperature of calcination, get solid sodium aluminate, then get the impurities separated gradually, iron oxide formation easy hydrolytic acid sodium, iron silicon oxide and titanium dioxide form does not dissolve in water calcium silicate and calcium titanate, resulting from the separation of sodium aluminate solution, recanalization into carbon dioxide, aluminium hydroxide precipitation. The preparation of aluminum hydroxide can also use this method.

relative to bayer process, soda-lime sintering process trival, high cost, low purity, but soda lime to deal with the lower bauxite, alumina and silica ratio is an important significance.