Method for full utilization of sodium chloride waste salt residue as resources by combining low-temperature roasting and interface regulating

Abstract

The invention discloses a method for full utilization of sodium chloride waste salt residue as resources by combining low-temperature roasting and interface regulating. The method comprises the following steps of (1) roasting the sodium chloride waste salt residue, cooling to room temperature, adding water into solid after cooling, stirring, and completely dissolving, so as to obtain a solution; (2) using the solution obtained in step (1), stirring, adding n-hexane and sodium oleate, standing and delaminating after adding, separating the liquids at upper layer and lower layer, drying the liquid at upper layer, and recycling, so as to obtain carbon; (3) using the separated liquid at lower layer in step (2), stirring, adding sodium carbonate, standing after adding, filtering, drying the filter residue after filtering, and recycling; (4) adding hydrochloric acid into the filtered solution in step (3), standing, heating, separating the separated crystal after heating, and drying. The method has the advantages that the technology is simple, the cost is low, the effect is quickly taken, the treatment amount is large, the purifying is thorough, and all waste salt can be utilized.

Description

technical field [0001] The invention belongs to the field of purification and recovery of industrial waste salt slag, and in particular relates to a method for resource utilization of sodium chloride waste salt slag in combination with low-temperature roasting and interface regulation. technical background [0002] In the production process of many fine chemicals, chemical pesticide products or intermediates, a large amount of by-product waste salt containing toxic and harmful chemicals is produced, such as producing 1 ton of hydrazine hydrate, which produces 4-5 tons of by-product chlorine containing toxic and harmful chemicals For every 1 ton of glyphosate pesticide produced, 1.1 to 1.4 tons of sodium chloride salt slag is a by-product containing toxic and harmful chemicals, and the production of trimethyl orthoformate produces chlorine as a by-product containing toxic and harmful chemicals. Sodium chloride waste salt slag, the annual by-product of the national chemical in...

AI Technical Summary

Problems solved by technology

However, these methods require pre-drying of waste salt slag and require the particles of waste salt slag to be uniform and as small as possible, and it is very easy to cause blockage and damage to the device

(2) Secondary concentration and crystallization treatment after dissolution and refining: This method is to redissolve the waste salt slag in fresh water, and recycle it after chemical treatment, concentration and crystallization again, such as CN105883911B molten salt chlorination slag recycling treatment method, CN103979576A one The method of evaporating and crystallizing salt slag from ammonium sulfate-containing organic wastewater; but these methods have high disposal costs, and secondary wastewater is generated, and the effect of physical and chemical treatment after dissolution is difficult to guarantee. The water content of salt recovered by recrystallization is high, and some still have a large Crystal water, low secondary use value

This disposal method is expensive, not only occupies a large amount of land, but also has the risk of secondary environmental damage caused by external factors such as geological disasters

[0004] At present, although most people focus on the research on the synthesis and preparation of front-end chemical products, there are relatively few studies on the comprehensive recovery and treatment of waste salt in the process. Therefore, the waste salt produced in the synthesis process of many chemical products has not been effectively obtained. processing, resulting in the waste of a large amount of recyclable resources