Application

Alumina is a white solid insoluble in water, and is also called bauxite in the mining, ceramic industry and materials science. It belongs to amphoteric oxides, soluble in inorganic acid and alkaline solution, relative density 4.0, the melting point of about 2000℃. Industrial alumina is the dehydrated product of various oxidation hydrates by thermal decomposition, and they form a series of homogeneous crystals, some in the dispersed phase, some in the transition state.

Reasons for foaming in the production of alumina

Bauxite ore has a high silicon content, and in order to improve the content of alumina, flotation agents are generally added in the flotation process, resulting in a large number of organics which has surface-active substances, then will cause a large number of foams in the slurry during the decomposition process, thus seriously affecting the yield and quality of alumina. Moreover, in the modified Bayer process of alumina production, due to chemical reactions and external agitation, a large number of bubbles are easily produced in the alumina solution system. These foams will seriously affect the efficiency of the evaporator and reduce the flow of materials, resulting in a reduction in the decomposition efficiency of the machine, and more seriously it will affect the operation of the machine and the quality of the product.

Alumina defoamer is a kind of refined non-silicon emulsion, which is a milky white or transparent liquid in appearance. It has strong defoaming and antifoaming ability, and can withstand high temperature and high pressure and strong acids and alkalis. Adding a small amount of alumina defoamer to the foaming system helps to make the alumina hydroxide better achieve crystal transformation at high temperature, maintain the balance of liquid amount in the circulation system, and evaporate and concentrate to meet the requirements of the Bayer process slurry. The defoamer can also effectively improve the quality of alumina, and has no adverse effects on bauxite dissolution, red mud sedimentation, aluminate solution decomposition, mother liquor evaporation and other processes. In the process of alumina production, the defoamer will not undergo hydrolysis, and long-term work will not affect their foam inhibition. In addition, it can also improve the purity of the overflow liquid during the separation of red mud.