Method for producing magnesium hydroxide from mixed solution containing magnesium chloride and calcium chloride by lime seeding method

Abstract

The invention discloses a method for producing magnesium hydroxide from a mixed solution containing magnesium chloride and calcium chloride by a lime seeding method. The method is capable of producing high-purity magnesium hydroxide through the steps of adding the magnesium hydroxide to the mixed solution containing magnesium chloride and calcium chloride, stirring and then slowly adding lime milk, wherein the produced high-purity magnesium hydroxide is good in filtration performance, easy to wash and capable of completely separating calcium from magnesium. The calcium chloride solution left after the magnesium hydroxide precipitates can be used for producing crystalline calcium chloride through evaporative crystallization. The method is changeable in production scale, wide in application, simple in process route, low in investment, low in energy consumption, free of pollution to environment, good in calcium-magnesium separation effect, simple and convenient to operate and low in production cost; and therefore, a quite effective, economical and practicable way is provided for producing the magnesium hydroxide from the mixed solution of magnesium chloride and calcium chloride.

Description

technical field

[0001] The invention relates to a method for producing magnesium hydroxide by a lime seed crystal method in a mixed solution containing magnesium chloride and calcium chloride, and belongs to the field of resource recovery and utilization. Background technique

[0002] In the chemical production process, when acid and alkali are neutralized, a large amount of mixed solution of magnesium chloride and calcium chloride will be produced. The solution after stirring and leaching of laterite nickel ore with hydrochloric acid, calcium carbonate iron removal, and nickel precipitation with lime is also a mixed solution of magnesium chloride and calcium chloride. It is difficult to separate the mixed solution of magnesium chloride and calcium chloride. Direct evaporative crystallization, the value of the obtained magnesium chloride, calcium chloride mixture is low, not economical.

[0003] In order to reduce the impact of the discharge of the mixed solution containing...