Technique for extracting vanadium pentoxide by tunnel kiln calcification roasting

Abstract

The invention relates to a method for extracting vanadium pentoxide by calcification and calcination of tunnel kiln coal gas, which comprises the steps of: mixing mineral soil and calcium oxide at a proper proportion, crushing, squeezing to obtain bricks, stacking on a kiln cart, placing into a coal gas tunnel kiln, calcinating at a certain temperature, pulverizing the calcinated bricks with a ball mill, placing the obtained powder into a large stirring tank, leaching with low concentration sulphuric acid solution under stirring to obtain slurry, press filtering with a press filter, washing, separating, transferring the filtrate to a ion-exchange column for exchange and enrichment, purifying to obtain ammonium metavanadate, and performing thermal decomposition with an electrothermal burning furnace to obtain vanadium pentoxide. The inventive method has the advantages of low production equipment investment, convenient and accurate process condition control, low production operating cost, high product extraction yield (mean value about 75%), and high product purity (over 99%). The exhaust gas emission meets the standards, the waste water is recycled and reused without external discharge, and the waste residues are integrally utilized to produce bricks, so as to realize clean and environmentally friendly production.

Description

technical field [0001] The invention relates to a process for extracting alum pentoxide by roasting, in particular to a process for extracting alum pentoxide by calcification roasting in a tunnel kiln. Background technique [0002] At present, the technologies for extracting vanadium pentoxide from vanadium ores in industry include roasting with salt to extract vanadium (including low-salt roasting), roasting without adding any additives, strong acid leaching to extract vanadium, and calcification roasting. Roasting with salt is already a high-pollution technology prohibited by domestic orders. The main problem is that a large amount of highly toxic waste gas mixed with hydrogen chloride and chlorine is produced during the roasting process, which is difficult to purify and seriously pollutes the environment. The extraction rate of vanadium in the ore is low, generally around 40%-50%. Roasting technology without adding any additives has a strong selectivity for ore, and only...

AI Technical Summary

Problems solved by technology

The problem with this technology is that the extraction rate is too low, only 35%-45%, the requirements for the ore are harsh, and it does not meet the conditions for industrial promotion

Although the vanadium extraction technology by strong acid leaching has the advantages of not needing roasting process and less waste gas pollution, the consumption of sulfuric acid is large, the equipment investment is high, and the production cost is about 50% higher than that of the roasting method, and the content of water-soluble heavy metal salts in the wastewater is too high, resulting in High water treatment costs and serious wastewater pollution

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