Method for preparing highly pure magnesium hydroxide and magnesium hexa-silicate by using olivine tailing mine

Abstract

The invention discloses a method for preparing highly pure magnesium hydroxide and magnesium hexa-silicate by using olivine tailing mine, which comprises the following steps: step one. olivine tailing mine and muriatic acid are blended, leached and reacts; step two. pickle liquor leached by acid is added into an enamel reactor and oxidized by adding oxidant hydrogen peroxide; step three. the component of a solid product after reaction is a ferric oxide which is washed and dried after solid-liquid separation to be iron oxide red; step four. filtrate after solid-liquid separation is continously added with ammonia water; step five. sizing agent containing magnesium hydroxide stays in reactant, aged, washed, dried and ground to obtain highly pure magnesium hydroxide; step six. solid leached by muriatic acid reacts with caustic soda to produce serous fluid containing sodium silicate; and step seven. reaction product which reacts with caustic soda solution is filtered and washed to obtain magnesium hexa-silicate. The method causes magnesium oxide to be fully recycled. The method ensures complete circulation of ammonia, increases yield of magnesium oxide in mineral, reduces the cost of magnesium hydroxide, and simultaneously ensures the purity of the magnesium hydroxide which reaches more than 99%.

Description

technical field [0001] The invention belongs to the field of non-metallic mineral processing and environmental protection, and more specifically relates to a method for preparing high-purity magnesium hydroxide and magnesium hexasilicate by using olivine tailings, which can be used to treat the remaining tailings after producing refractory materials and other products from olivine mines granular or powder. Background technique [0002] Peridotite is an ultrabasic deep rock formed by the decomposition of olivine crystallized from basaltic magma. Peridotite is composed of olivine and pyroxene, and the rest is a small amount of hornblende, biotite, magnetite, etc., often in a unique olive green, sometimes brown or black, with a specific gravity of 2.94 to 3.37. If the olivine content exceeds 90%, it is called pure peridotite. Pure peridotite has bright olive green, dark green or dark gray, etc., and is dense and massive. It is a holocrystalline euhedral or other shape granula...

AI Technical Summary

Problems solved by technology

However, the resources are severely altered, and the unaltered olivine (MgO≥44%, ignition loss≤3%) is only tens of millions of tons, and it is buried at a depth of hundreds of meters, and accounts for more than 90% of the olivine. Altered to varying degrees into peridotite and serpentine with MgO 8%, especially hundreds of millions of tons of altered peridotite (serpentine) in the surface layer of the mining area, MgO 10%, can not be directly used in industry, it can be used as metallurgical refractory after calcination

Therefore, some of them can only be used as low-grade calcium-magnesium phosphate fertilizer raw materials, and the resource utilization rate is low.

In the process of olivine mining, about 30% of olivine powder has no economic value and can only be discarded, which not only wastes resources, but also has an impact on the environment

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