A method for treating vanadium industrial wastewater with semi-dry flue gas desulfurization ash

Abstract

The invention discloses a method for treating vanadium industrial wastewater by the aid of semi-dry flue gas desulfurization ash. The method includes steps of (1), adding the semi-dry flue gas desulfurization ash into the vanadium industrial wastewater; (2), adding inorganic acid into the vanadium industrial wastewater to regulate a pH (potential of hydrogen) value of the vanadium industrial wastewater and stirring the inorganic acid and the vanadium industrial wastewater to obtain mixtures; (3), allowing the mixtures to stand still, separating supernatant from precipitates, carrying out pressure filtration on the precipitates to obtain calcium sulfate and mixing filter liquid and the supernatant with each other to obtain first mixed liquid; (4), adding sodium hydroxide into the first mixed liquid, stirring the first mixed liquid and the sodium hydroxide to obtain second mixed liquid, adding flocculating agents into the second mixed liquid and continuing to stir the flocculating agents and the second mixed liquid to obtain third mixed liquid; (5), allowing the third mixed liquid to stand still, separating supernatant from precipitates, carrying out pressure filtration on the precipitates to form chromium-containing green mud and mixing filter liquid and the supernatant with each other to obtain fourth mixed liquid; (6), leading the fourth mixed liquid into an ammonia nitrogen precipitating tank, stirring the fourth mixed liquid, adding magnesium salt and phosphate into the fourth mixed liquid to obtain fifth mixed liquid, regulating a pH value of the fifth mixed liquid and then continuing to stir the fifth mixed liquid; (7), allowing the fifth mixed liquid to stand still and separating supernatant from precipitates. The method has the advantages that semi-dry desulfurization solid waste can be recycled, accordingly, the wastewater treatment cost can be reduced, the problems of secondary pollution and land occupation of semi-dry desulfurization ash can be solved, and the method has high environmental benefits, economic benefits and social benefits.

Description

technical field [0001] The invention belongs to the technical field of waste water and solid waste treatment, and in particular relates to a method for treating vanadium industrial waste water with semi-dry flue gas desulfurization ash. Background technique [0002] Vanadium is known as a metal "vitamin" and is widely used in metallurgy, chemical industry and other industries as alloy additives and catalysts in organic chemicals. At present, the production process of its main product vanadium pentoxide is mostly sodium roasting process. The process is: vanadium slag crushing - sodium roasting - water leaching of vanadium - leachate purification - acid ammonium salt vanadium - melting; this process produces a large amount of highly polluted acidic wastewater, which is characterized by high salinity, large discharge and high heavy metal content , according to the requirements of "GB 26452-2011 Vanadium Industrial Pollutant Discharge Standard", the total chromium, hexavalent ch...

AI Technical Summary

Problems solved by technology

Although these methods have certain effects, there are generally problems such as high treatment cost, low treatment efficiency, easy to produce secondary pollution and failure to fully meet the discharge standards.

Images