Method of using waste aged brine to prepare magnesium chloride particles

Abstract

The invention discloses a method of using waste aged brine to prepare magnesium chloride particles. A tail liquid of the water aged brine after production of potassium fertilizer is used as a raw material for tedding in a salt field to precipitate bischofite. The method comprises the following steps of primary refining, wherein impurity cations in the magnesium chloride brine are removed to obtainprimary refined brine; secondary refining, wherein secondary refining is carried out to remove impurity anions in the primary refined brine to obtain secondary refined brine; neutralizing, wherein the secondary refined brine is neutralized; evaporating and concentrating, wherein the neutralized refined brine is evaporated and concentrated; granulating, wherein the concentrated refined brine is granulated; screening, wherein crude magnesium chloride wet particles obtained by granulation are screened; dewatering, wherein the qualified magnesium chloride wet particles obtained by screening are dewatered to obtain dry magnesium chloride particles. The method of using the waste aged brine to prepare the magnesium chloride particles is simple in process, energy-saving and environmentally friendly, the prepared magnesium chloride particles have good quality and high recoverability rate, and industrialized production can be easily achieved.

Description

technical field [0001] The invention relates to the field of preparation of inorganic salts, in particular to a preparation method of magnesium chloride particles. Background technique [0002] Potassium fertilizer is a fertilizer often used in agricultural production, and it plays a decisive role in the growth of crops. During the conventional production of potash fertilizers, waste liquid containing magnesium chloride brine with higher magnesium chloride content will be generated. Thus, the preparation of magnesium chloride by magnesium chloride waste liquid has become a new direction for the preparation of high-purity magnesium chloride. [0003] CN201310099090 discloses a production process of magnesium chloride granules. In the production process, the pre-filtered liquid magnesium chloride is settled and vapor-liquid separated before granulation. Although this method is simple, the magnesium chloride purity that obtains is low. CN20081015821 discloses that a high-pur...

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Problems solved by technology

[0005] The present invention first removes impurity ions in bischofite by using chemical reaction and ion exchange methods, then granulates the obtained magnesium chloride brine, and obtains magnesium chloride particles with higher purity by screening the particle size, which solves the problem of preparing magnesium chloride particles in the prior art. The obtained magnesium chloride particles have low purity, complex production process and high process cost

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