Activated magnesia, and preparation method and application thereof

Abstract

The invention relates to the technical field of inorganic salts, and provides an activated magnesia, and a preparation method and an application thereof. The preparation method comprises the followingsteps: mixing light burned magnesia powder, magnesium chloride and water, and carrying out a hydrothermal reaction to obtain a magnesium hydroxide precipitate and a calcium chloride solution; soakingthe magnesium hydroxide precipitate in an aqueous ammonium chloride solution for leaching to obtain a magnesium chloride solution, ammonia gas and leaching residues; mixing the magnesium chloride solution, ammonia gas and carbon dioxide, and carrying out a magnesium precipitation reaction to obtain a basic magnesium carbonate precipitate; and sequentially drying and calcining the basic magnesiumcarbonate precipitate to obtain the activated magnesia. Insoluble silicon, calcium and other impurities are left in ammonium chloride leaching residues through magnesium chloride decalcifying and ammonium chloride magnesium leaching, so the improvement of the purity and activity of the final product is benefited. The magnesia obtained through the method is high in purity and activity, the mass content of MgO in the activated magnesia is larger than or equal to 98%, and the activity is larger than 95%.

Description

technical field [0001] The invention relates to the technical field of inorganic salts, in particular to an active magnesium oxide and its preparation method and application. Background technique [0002] In the hydrometallurgical process of minerals such as laterite nickel ore, copper-cobalt ore, and hydrocobalt ore, nickel and cobalt are converted into nickel hydroxide and cobalt hydroxide to precipitate, and then the precipitate is separated from the solution to achieve separation and purification of nickel and cobalt. Purpose. Sodium hydroxide is a common neutralizing and precipitating agent, but when the conditions are not controlled properly, it is easy to make nickel hydroxide and cobalt hydroxide form colloids, resulting in difficulties in filtration and washing, and defects such as high water content in filter cakes. Using magnesium oxide to precipitate nickel and cobalt, the formed nickel hydroxide and cobalt hydroxide have good crystal morphology, are easy to fil...

AI Technical Summary

Problems solved by technology

There are many types of active magnesium oxide in the domestic market. When it is used to precipitate nickel and cobalt, the product quality cannot be guaranteed uniformly. The residual impurity magnesium content in the nickel hydroxide and cobalt hydroxide precipitates produced is too much, which cannot meet the metallurgical process requirements.

[0004] At present, the production methods of active magnesium oxide commonly used in industry mainly include: brine soda ash method, brine ammonia water method, brine ammonium bicarbonate method, dolomite carbonization method, magnesite ammonium bicarbonate method, etc. And other properties often cannot meet the requirements of active magnesium oxide for metallurgical precipitation

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