APT (ammonium paratungstate) production wastewater recycling method

Abstract

The invention discloses an APT (ammonium paratungstate) production wastewater recycling method. An APT production line which can realize zero emission of wastewater and is high in water recycling rate can be established, tungsten, molybdenum and other useful metals in a tail liquid can be recycled, loss of tungsten can be avoided, and the added output value can be increased, so that the economic benefit is increased; one part of the discharged tail liquid is recycled to be used for pulping, the other part is evaporated, steam condensate is recycled to be used for preparation of a back washing agent, and thus, zero emission of wastewater is realized. A conventional steam heating manner is changed in a caustification process, a good effect can also be realized through storage tank standing treatment, and the utilization rate of lime can reach 80%, so that steam is saved. Produced APT can meet the notational 0-level standard.

Description

technical field [0001] The invention relates to the field of resource recovery and reuse, in particular to a method for recycling waste water from APT production. Background technique [0002] In the prior art, there are three industrial methods for purifying and removing impurities from sodium tungstate solution to prepare ammonium paratungstate APT (Ammoniumparatungstate) solution, namely the classic chemical method, ion exchange method and solvent extraction method. , Low yield has been less used at present. Ion exchange method and solvent extraction method have their own advantages and disadvantages, and each manufacturer chooses according to the specific situation. [0003] Compared with the solvent extraction method, the ion exchange method can remove phosphorus, arsenic, silicon and other anion impurities while transforming. The process flow is short and the operation is relatively simple, but it has the disadvantages of large water consumption and waste water discha...

AI Technical Summary

Problems solved by technology

[0005] The purification and impurity removal method of APT prepared by solvent extraction method is difficult to meet the standards of environmental protection, zero discharge and water recycling rate.

There are at least the following technical problems in the prior art: waste water discharge outlets must be installed, and the waste water pollution problem cannot be completely eradicated; most of the auxiliary materials are disposable consumables, and the leaching agent used in the leaching process is excessive. Either directly discharged, or need to use the corresponding acid or alkali to neutralize and then discharged, the consumption of auxiliary materials is high, and the production cost is high; some tungsten and molybdenum elements are inevitably brought out in the wastewater, and the recovery rate of tungsten elements is low; tungsten A large amount of high-salt waste liquid is produced during the transformation of sodium acid solution, and ammonia nitrogen waste water is produced by evaporating and crystallizing the mother liquid; the equipment investment is large, the process flow is long, the productivity is low, and it is difficult to achieve continuous production

Images