The invention discloses a sand-like aluminum oxide seed decomposition additive. The additive is prepared from, by weight, 1-10 parts of anionic surfactant of natural vegetable fat, 1-15 parts of oily matter, 5-15 parts of low carbon alcohol-capped block-type polyepoxyalkane high-molecular compounds, 5-35 parts of nonionic surfactant of natural vegetable oil low-carbon polyol ester and ether and 60-75 parts of water. The additive enables aluminum hydroxide microcrystals decomposed out of a sodium aluminate solution to agglomerate into sand-like aluminum oxide with a high particle size and high strength, meanwhile, filtering can be improved, scarring can be delayed, roasting efficiency can be improved, the decomposition rate can be stabilized, technological fluctuation can be suppressed, product quality can be improved, and production cost can be lowered.

Sand-like aluminum oxide seed decomposition additive

The invention provides a production method of aluminum hydroxide, and relates to a preparation method of epigranular aluminum hydroxide with a low oil absorption value. The production method is characterized in that a sintering method refined solution is used as a raw material in the production process of the aluminum hydroxide, and the production process of the aluminium hydroxide comprises the steps that: (1) the sintering method refined solution is used as the raw material to conduct first-stage crystal-seed-added carbonation precipitation; (2) size of the first-stage crystal-seed-added carbonation precipitation is filtered and first-stage aluminum hydroxide is obtained; (3) the first-stage aluminum hydroxide obtained in the step (2) is added to a sintering method refined solution same as that in the step (1) to be mixed therewith, and second-stage carbonation decomposition is conducted; (4) size obtained after the second-stage carbonation decomposition in the step (3) is washed by using soft water, filtered and dried, and a finished aluminum hydroxide product is obtained. The preparation method provided by the invention has the advantages of simple technology, easiness in implementation and relative low cost. The aluminum hydroxide product manufactured by adopting the preparation method has the advantages of high purity, even crystal structure, smooth surface and good stability, and can be widely applied to the packing field.

Production method of aluminum hydroxide

This invention presents a new process for making sandy alumina, featuring a new carbonation decomposition and a seeding-stirring decomposition step, which enables one to obtain high strength sandy aluminium hydroxide from refined solution of sintering process. This process consisting of three steps: preparing seeds by carbonation decomposition at 75-90 deg.C adding the seeds thus made at 65-85 deg.C for making sandy aluminium hydroxide through carbonation decomposition, and adding the sandy aluminium hydroxide made above as seeds to carry out stiring decomposition.

Zhou Zhongyu

Papers

Method of making sandy alumina from refined solution of sintering process