Method for preparing basic magnesium carbonate by using combinative alkali system high-salt heavy-ash mother solution

Abstract

The invention discloses a method for preparing basic magnesium carbonate by using a combinative alkali system high-salt heavy-ash mother solution. The method comprises the following steps: (1) dissolving industrial magnesium chloride into a solution with the concentration of 1-1.45mol / L, heating to 80-90 DEG C, and filtering to remove insoluble substances; (2) heating a high-salt heavy-ash mother solution to 50-60 DEG C, keeping the temperature constant, and then filtering to remove calcium ion impurities; (3) adding the filtered high-salt heavy-ash mother solution into the filtered industrial magnesium chloride solution while stirring for fully reacting, and then keeping the temperature of the solution after reaction for 2-3 hours, wherein the molar volume ratio of the added amounts of the high-salt heavy-ash mother solution and the industrial magnesium chloride solution is 1.2-1.5; and (4) filtering a magma solution, washing by using deionized water at the same time, and drying at 120-130 DEG C to obtain a basic magnesium carbonate product. The magnesium oxide content of the basic magnesium carbonate prepared by the method disclosed by the invention is about 41% and can reach an industrial standard.

Description

technical field

[0001] The invention relates to a method for preparing basic magnesium carbonate, in particular to a method for preparing basic magnesium carbonate by using a combined alkali system high-salt heavy ash mother liquor. Background technique

[0002] Magnesium basic carbonate has a wide range of uses, mainly used in rubber, enamel, plastic products, paint, pharmaceuticals, electronics, cables and other industries. One, there is a great demand in our country. During the production of heavy ash in the combined soda system, chloride ions in the heavy ash mother liquor continue to accumulate. When the chloride ion content is usually greater than 60g / L, part of the mother liquor needs to be discharged to maintain system balance and ensure qualified products. The main components of the discharged high-salt heavy ash mother liquor are sodium carbonate and sodium chloride. Therefore, the preparation of magnesium carbonate by using the high-salt heavy ash mother liquor a...