Method for preparing trihydrated magnesium carbonate by using continuous crystallization process

Abstract

The invention belongs to the technical field of salt chemical industrial production, concretely, the invention relates to a method for preparing trihydrated magnesium carbonate by a using continuous crystallization process. The technical schemes of the present invention comprises: selecting high concentration magnesium chloride or high ratio of magnesium to lithium brine, ammonium carbonate as raw materials, adding into a continuous crystallizer for crystallizing, adding a crude product of trihydrated magnesium carbonate obtained by crystaling into an aging device for aging, obtaining a trihydrated magnesium carbonate crystal with good form and high purity for condition for providing conditions to produce high purity magnesium oxide. According to the method of the present invention, continuous crystallization in a process of producing trihydrated magnesium carbonate can be realized, the stability and automation degree of the crystallization in the process of producing trihydrated magnesium carbonate can be effectively raised, and the quality of products is increased as well as the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of salt chemical production. Specifically, the invention relates to a method for preparing magnesium carbonate trihydrate by using a continuous crystallization method. Background technique [0002] my country has vast salt lake resources in Qinghai, Tibet, Xinjiang and other regions, and the salt lakes are rich in potassium, magnesium, lithium and other resources. At present, the area mainly produces potash fertilizer, and a large amount of brine containing magnesium chloride and lithium chloride is discharged during the production process of potash fertilizer. This part of brine has not been effectively utilized, resulting in the waste of magnesium and lithium resources, and also the depletion of potassium resources and serious environmental pollution. With the development of the national economy, the demand for magnesium products in the domestic market is also increasing, but high-end magnesium products s...

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Problems solved by technology

[0025] At present, the processes for preparing magnesium carbonate trihydrate in literature and production are all batch crystallization processes, which have a low degree of automation, small capacity of a single set of equipment, long reaction time, lack of continuity in production before and after, and production is easily affected by human factors, resulting in product quality. Unstable phenomenon, not conducive to large-scale production of magnesium carbonate trihydrate

The continuous method crystallization process has the advantages of high production capacity, high degree of automation, stable product quality, etc., but because magnesium carbonate trihydrate has its special crystallization process characteristics and product quality requirements, such as the characteristics of reaction crystallization, there are certain conditions in the crystallization process. The induction period, the rod-shaped product is easily broken during the crystallization process and affects the particle size and particle size distribution of the product, and the concentration of remaining raw materials in the mother liquor after crystallization is relatively high, making it difficult for the traditional continuous crystallization process to meet the needs of continuous crystallization of magnesium carbonate trihydrate.

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