Preparation method of basic magnesium sulfate whiskers

Abstract

The invention discloses a preparation method of basic magnesium sulfate whiskers. The preparation method comprises the following steps: S1, mixing a magnesium hydroxide source, a sulfate source and water to obtain a mixture, wherein the mass percent of magnesium hydroxide in the magnesium hydroxide source is not lower than 50%; S2, carrying out hydrothermal reaction on the mixture for 1-40 hours at the temperature of 100-300 DEG C, so as to obtain suspension; and S3, carrying out solid-liquid separation on the suspension, so as to obtain a solid phase and a liquid phase, washing, and drying the solid phase, so as to obtain the basic magnesium sulfate whiskers. According to the preparation method of the basic magnesium sulfate whiskers, the magnesium hydroxide source with relatively low magnesium hydroxide purity is taken as a preparation raw material; on one hand, the pollution and waste of byproduct magnesium hydroxide magnesium slag are reduced, and thus the magnesium harm problem is effectively controlled; and on the other hand, ammonia water, sodium hydroxide and the like are avoided from being used as a base source, and thus the preparation method is reduced. Meanwhile, the preparation method does not need other additives and is simple in technology; and the obtained basic magnesium sulfate product has high purity and good dispersibility.

Description

Technical field [0001] The invention belongs to the technical field of inorganic material preparation, and specifically relates to a method for preparing basic magnesium sulfate whiskers by adopting a hydrothermal method. Background technique [0002] China is rich in sea-lake brine and ore magnesium resources. Among them, magnesite reserves are 3.145 billion tons, accounting for 22.5% of the world's total reserves. The magnesite ore is of high grade and the reserves are highly concentrated. The reserves of Liaoning and Shandong provinces account for the country's total reserves. At the same time, China’s salt lake brines are particularly rich in magnesium resources, which are mainly distributed in Qinghai, Tibet, Xinjiang, Inner Mongolia and other places. The magnesium salt reserves in the salt lake brines are 4.816 billion tons, of which 3.143 billion tons of magnesium chloride and 1.673 billion of magnesium sulfate Ton. [0003] In the process of utilizing magnesium resources, ...

AI Technical Summary

Problems solved by technology

But, in the various technology of preparing basic magnesium sulfate whisker at present, mainly there is following problem: (1) use sodium hydroxide, ammoniacal liquor, magnesium oxide, high-purity magnesium hydroxide etc. as alkali source in the selection of raw material, cause production cost (2) Magnesium hydroxide is prepared by using the by-product magnesium salt of Haihu Salt Chemical Industry as raw material, and then reacted with sulfate to obtain basic magnesium sulfate whiskers; or low-grade magnesite is calcined for hydration reaction , add sulfuric acid solution again and make the mixed liquor of magnesium hydroxide and magnesium sulfate, react to obtain basic magnesium sulfate whisker; Although these two kinds of methods are lower in raw material cost, technological process is comparatively complicated; (3) need to add in the preparation process Seed crystals, surfactants, solubilizers, dispersants and other external reagents; (4) The raw materials need to be activated, which makes the process more complicated and the cost higher

[0006] Therefore, it is necessary to search for a method for preparing basic magnesium sulfate whiskers with simple raw materials, low cost and simple process. At the same time, the method can also solve the pollution and waste problems of by-product magnesium hydroxide slag

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