Preparation Of Oil-soluble Defoamers And Their Research And Application On The Seed Precipitation From The Sodium Aluminate Liquor

Being different from foreign aluminum ore, our country's is mainly on silicates which contain mass silicon. In order to raise the content of Al2O3, flotation agent is added is used during the process of flotation. Because of the enrichment of organism in the flotation agents, some surfactant subjects will lead the pubescences of sodium aluminate liquor which affects the yield and quality of product seriously. So, it is necessary to add proper additives during the decompose process. Though the kind of Si-O-C defoamers which is widely used in the industry can wipe off the foams in the system effectually, it does decompose under the condition of high temperature, high alkali and water-system of seed precipitation of sodium aluminate liquor. Then it will loose the ability of defoaming. The research on inhibiting foams of the seed precipitation of sodium aluminate liquor is few domestic and abroad at present. Inhibiting foams of the seed precipitation of sodium aluminate liquor by oil-soluble additives of Si-C is first put forward in this article.First of all, three anion surfactants which contain Si-C bond in the chain backbone were synthesized. During this process, the influence of solvent dose, time and temperature on the yield ware reviewed, and then the compound was test by IR.Secondly, we confect five oil-soluble additives using the above anion surfactant which is selected by the effect of defoaming and the other oil-soluble materials.Thirdly, using the sodium aluminate liquor of Shandong Xinfa Huayu Aluminum Industry as material, we pick out the best additive; in the whole experiment, the additive 4 can wipe off foams efficiently no matter by half life or by the height of foam, and on the premise of that there is no change of precipitation ratio of sodium aluminate solution, It also can improve the quality of products, and it can't take bad effect to the quality of aluminum hydroxide and alumina.Fourthly, additive 4 is more effective than the foreign additives. Its 1000 ratio reached to 7.786. and the effects on precipitation ratio and quality of products are more remarkable than the others. Finally, we do industry experiment with the additive 4 in test in Shandong Xinfa Huayu Aluminum Industry. In this part, we analyse several factors, for example, the changes of foams'height, precipitation ratio, the granularity of alumina, the concentration of organic materials, he quality of aluminum hydroxide, and so on. The results show that the additive 4 can wipe off the foams of sodium aluminate liquor, and on the premise of that there is no change of precipitation ratio of sodium aluminate solution, It also can improve the quality of products, and don't take bad effect to the other working procedure in the production of alumina. All above results show that the oil-soluble additive 4 has good properties, and it can take good economy benefit to the alumina enterprise, so it could be used in the industry of alumina production.