Method for removing arsenic and recycling tungsten from tungsten smelting wastewater

Abstract

The invention discloses a method for removing arsenic and recycling tungsten from tungsten smelting wastewater, which comprises the following steps of: 1, adding inorganic acid into waste liquor after sodium tungstate solution is subjected to strongly basic anion resin exchange to adjust the waste liquor to be faintly acid, namely pH=3-6, and simultaneously adding a trace amount of flocculating agent; 2, injecting the faintly acid wastewater from which suspended matters are filtered out into an exchange column filled with D313 or D314 type anion resin, and adsorbing all arsenic and phosphorus in the wastewater by using the D type anion resin; and 3, desorbing the resin by using caustic soda solution, making 90 percent of tungsten crystallized and separated out in a form of Na2WO4.2H2O, reacting most harmful elements with an additive, and removing a slag phase. The method has the advantages that: the resin can thoroughly adsorb the tungsten and arsenic, so that the harmful element arsenic in the discharged production wastewater is reduced to less than 0.05mg / L from 1.5mg / L; the metal recovery rate is improved to 96-97 percent from 93-94 percent; and the tungsten detection in the in-process control process is saved, so the operation is simplified, the product quality is ensured, and the consumption of a NH4Cl strippant and water can be reduced.

Description

technical field [0001] The invention relates to a comprehensive utilization method of tungsten smelting wastewater, in particular to a method for removing arsenic in tungsten smelting wastewater and recovering tungsten. Background technique [0002] At present, the production of ammonium paratungstate (APT) in my country generally adopts the self-developed ion exchange process. Its advantages are stable product quality and easy operation. However, the major disadvantage of this process is that it consumes a lot of water, which consumes more than 100 tons of water per ton of APT produced. Harmful substances in raw materials such as arsenic, phosphorus and organic flotation agents are not adsorbed by the resin during the ion exchange process, and more than 95% enter the production wastewater (exchange liquid); in addition, my country's tungsten resources have been mined for more than a century , high-quality tungsten ore is getting less and less, especially wolframite resourc...

AI Technical Summary

Problems solved by technology

This kind of raw material not only contains excessive harmful elements, but also contains a large amount of flotation reagents, which has a harmful effect on the whole process of APT production, especially on the ion exchange process, which not only reduces the exchange capacity of the resin, but also affects Resin to WO 4 2- Due to the thoroughness of the adsorption, the phenomenon of tungsten "leakage" occurs from the beginning to the end, so that in addition to the above-mentioned harmful elements, the production wastewater also contains trace amounts of tungsten, which not only pollutes water resources, but also reduces the metal recovery rate of APT production

At present, the APT production plants in my country have not cleared and recycled the above-mentioned elements in the production wastewater because there is no applicable technology.

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