System and method for separating and recovering chlorine salts based on fly ash plasma melting

Abstract

The invention discloses a system and a method for separating and recovering chlorine salts based on fly ash plasma melting. The method comprises the following steps: high-salt and high-acid wastewater enters a wastewater regulating tank, and is homogenized, the wastewater is lifted into a coagulating sedimentation tank by a feeding pump, a reagent is added into the coagulating sedimentation tank, heavy metals and suspended matters in the wastewater are removed, solid-liquid separated wastewater in the sedimentation tank goes through an intermediate water tank, is pumped into a filtering or softening system by a pump, and is deeply treated, the obtained high-salt water enters an evaporative crystallization system, and undergoes sodium chloride and potassium chloride step-by-step separation, and the obtained mother liquor returns into the coagulating sedimentation tank to separate sulfates. The method and the system effectively remove pollutants in water, recover reuse water, can specially develop a sodium, potassium, chlorine and sulfate radical quaternary system salt separation system to obtain industrial byproducts meeting corresponding standards, solve the problem of separation and recovery of impurity salts in the "zero emission" process of high-salt wastewater, and also solve the problem of reuse of secondary fly ash after plasma melting.

Description

technical field [0001] The invention relates to the field of hazardous waste treatment and resource recovery, in particular to a chlorine salt separation and recovery system based on fly ash plasma melting. Background technique [0002] In recent years, waste incineration has gradually become the mainstream trend of domestic waste treatment in my country due to its advantages of reduction, harmlessness and resource utilization. However, a large amount of fly ash produced during the incineration process is rich in high concentrations of chloride salts, high levels of heavy metals that are easily leached, and traces of persistent organic pollutants (dioxins, furans), which are listed as hazardous wastes by countries all over the world. Melting and solidification can achieve the ultimate reduction, harmlessness and resource utilization of fly ash. It is one of the most advanced fly ash disposal technologies at present. Plasma melting has been paid more and more attention becaus...

AI Technical Summary

Problems solved by technology

However, there are a lot of soluble salts in waste incineration fly ash, mainly KCl, NaCl, MgCl 2 , ZnCl 2 , CaCl 2 Exist in the form of chlorine salts, inorganic chlorine salts will also volatilize with the flue gas during plasma melting and easily form secondary fly ash, causing secondary pollution

Flue gas wet treatment is an effective method to solve the secondary pollution of plasma melting flue gas, but it elutes the chloride in the flue gas to form high-salt wastewater with complex water quality components, and the impurities obtained after treatment, especially after evaporation and crystallization Salt (mainly sodium chloride, potassium chloride, sodium sulfate, etc.) is still hazardous waste, so how to effectively separate the miscellaneous salts in high-salt wastewater is an urgent problem to be solved for the comprehensive utilization of secondary fly ash

[0003] Chinese patents CN201210011044 and CN201610889351 mainly focus on the separation of two kinds of miscellaneous salts, sodium chloride and potassium chloride, sodium chloride and sodium sulfate, but the separation of more than three kinds of miscellaneous salts in high salt water, especially sodium, potassium, chlorine, sulfate, etc. Less salt separation in quaternary complex systems

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