Arsenic removal apparatus and method for purifying wet-process phosphoric acid by vulcanization

Abstract

The invention discloses an arsenic removal apparatus and method for purifying wet-process phosphoric acid by vulcanization. The apparatus herein comprises a screw conveyer, a vulcanizer chamber, a venturi mixer, a reaction tank and a solid-liquid separator. A vulcanizer is fed into the vulcanizer chamber through the screw conveyer; an outlet of the vulcanizer chamber is connected with a vulcanizerinlet of the venturi mixer; an outlet of the venturi mixer is connected with an inlet of the reaction tank; an outlet of the reaction tank is connected with the solid-liquid separator; the venturi mixer is also provided with a phosphoric acid solution inlet; the vulcanizer chamber is provided with a compressed air inlet; the reaction tank is an airtight device. Traditional stirring is replaced with the venturi mixer, so that materials are mixed well in the venturi mixer; the apparatus requires small floor area and has no power consumption, so that energy is saved, and the cost is reduced. Inaddition, the reaction tank is the airtight device, the vulcanizer has no need for being independently configured into a solution, overflow of hydrogen sulfide gas generated by the reaction is effectively prevented, field operation safety is improved, and the environment is protected.

Description

technical field [0001] The invention belongs to the field of phosphoric acid industry, and relates to a wet-process phosphoric acid vulcanization and arsenic removal purification device and method. Background technique [0002] As a basic chemical raw material, phosphoric acid is widely used in various fields such as medicine, chemical industry, and food. However, due to its high impurity content, wet-process phosphoric acid cannot be used in other fields other than the chemical industry. Arsenic in wet-process phosphoric acid mainly comes from phosphate rock, which fluctuates slightly according to the quality of phosphate rock. Although the content of arsenic is small, its presence often has a great impact on the quality of subsequent phosphate products, and it is one of the more difficult impurities in phosphoric acid to remove. The main methods for phosphoric acid to remove arsenic include chemical precipitation, solvent extraction, ion exchange and so on. [0003] At ...

AI Technical Summary

Problems solved by technology

The existing vulcanization arsenic removal device commonly used in the wet-process phosphoric acid industry is composed of a mixing tank and a settling tank. Under normal production operations, the vulcanizing agent and phosphoric acid fully react through mechanical stirring in the mixing tank. During the vulcanization reaction process, there will be The overflow of hydrogen sulfide gas affects the safety of on-site operation and the environment; at the same time, the entire device is limited by the technical limitations of mechanical stirring and natural settlement, and occupies a large area

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