Treatment method of sodium tetrachloroaluminate solid residues

Abstract

The invention relates to a treatment method of sodium tetrachloroaluminate solid residues. The treatment method comprises the following steps: (1) mixing sodium tetrachloroaluminate solid residues with water for dissociation, then adding a separating agent to separate out aluminum chloride hexahydrate, or directly mixing the sodium tetrachloroaluminate solid residues with the separating agent fordissociation, separating out aluminum chloride hexahydrate, and then carrying out primary solid-liquid separation to obtain an aluminum chloride hexahydrate solid and primary filtrate; and (2) carrying out concentration crystallization and secondary solid-liquid separation on the primary filtrate to obtain a sodium chloride solid and a secondary filtrate. According to the treatment method, an organic solvent does not need to be introduced, cross contamination does not exist, and the cost can be reduced; the aluminum chloride and the sodium chloride which are obtained by dissociating the sodiumtetrachloroaluminate solid residues are fully recycled, so that the high resource utilization of the sodium tetrachloroaluminate solid residues is realized, the obtained secondary filtrate can be returned to a solid residue dissociation stage to provide a separating agent, the concept of circular economy is embodied, and the method has the advantages of simple process flow, simplicity and convenience in operation and the like.

Description

technical field [0001] The invention relates to the technical field of inorganic chemistry, in particular to a method for treating sodium tetrachloroaluminate solid slag. Background technique [0002] Methylphosphine dichloride is an important organic chemical intermediate, which is widely used in pesticides, medicines, synthetic materials and other fields. At present, the domestic synthetic processes for preparing methyl phosphine dichloride mainly include ternary complex method and alkyl aluminum method. However, no matter what kind of synthesis process, after separating the product methyl phosphine dichloride, a large amount of solid waste will be generated, the main component of which is sodium tetrachloroaluminate, and also contains a small amount of impurities such as organic phosphine. Since sodium tetrachloroaluminate is easily soluble in water, solid waste is often dissolved in water and discharged directly, which will not only cause great pollution to the environm...

AI Technical Summary

Problems solved by technology

The method not only does not separate aluminum and sodium before the high-temperature reaction, but a large amount of phosphoric acid or phosphate needs to be added to the high-temperature reaction, which increases the processing cost, but also belongs to the high-temperature reaction with high energy consumption, and the product obtained by the high-temperature reaction is Mixture of sodium phosphate and aluminum tripolyphosphate, difficult to separate

[0007] In summary, the treatment methods disclosed in the prior art all have disadvantages such as complex process, high cost, and risk of cross-contamination. Therefore, it is urgent to develop an effective treatment method for sodium tetrachloroaluminate solid slag method to achieve the purpose of cost reduction, efficient and thorough resource utilization of sodium tetrachloroaluminate solid slag

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