Lithium deposition wastewater treatment system based on MVR (mechanical vapor recompression) evaporative crystallization and treatment method of system

Abstract

The invention discloses a lithium deposition wastewater treatment system based on MVR (mechanical vapor recompression) evaporative crystallization. The lithium deposition wastewater treatment system comprises a raw material tank, a condensate preheater, a vapor preheater, a forced circulation evaporator, a thickener, a centrifuge, a compressor and a vapor distribution drum, wherein raw materials in the raw material tank are input into the condensate preheater through a charging pump, and the condensate preheater is communicated with the vapor preheater through a pipeline; the raw materials inthe vapor preheater are input into the forced circulation evaporator through a pipeline, and the forced circulation evaporator comprises a heater I, a heater II and a crystallization separator, and the heater I and the heater II are mounted in a series connection manner. The lithium deposition wastewater treatment system has the following beneficial effects: in the actual production process, lithium carrying amount of anhydrous sodium sulfate is smaller than or equal to 0.08%; meanwhile, secondary steam condensate contains no lithium salt, content of sodium sulfate is smaller than or equal to100 PPm, and the system mainly applies to treatment of sodium sulfate wastewater generated by production of industrial-grade and battery-grade lithium carbonate from lepidolite and spodumene as raw materials.

Description

technical field [0001] The invention relates to the treatment of lithium-precipitating wastewater, in particular to a lithium-precipitating wastewater treatment system and a treatment method based on MVR evaporation and crystallization. Background technique [0002] The traditional process for treating lithium-precipitated wastewater generally adopts the traditional three-effect evaporation system for evaporation and crystallization of lithium-precipitated wastewater, and crystallizes anhydrous sodium sulfate, that is, sodium sulfate. Since the inorganic salt in the lithium sinking wastewater is mainly sodium sulfate, if the sodium sulfate is produced, thermal crystallization is required, and the evaporation temperature of the crystallization effect must be greater than or equal to 80°C. In the traditional multi-effect, the temperature of the secondary steam in the final effect is too high, resulting in excessive energy waste. Moreover, in the traditional multi-effect evapo...

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Problems solved by technology

However, in the current MVR treatment process, the amount of lithium contained in the sodium sulfate is greater than or equal to 0.2%, resulting in a large amount of waste of lithium elements, which indirectly leads to a large amount of waste of funds for enterprises.

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