Wet process phosphoric acid production device and method

Abstract

The invention discloses a wet process phosphoric acid production device and a method. The device comprises an acidolysis reaction tank, a swirler, a large crystal collecting tank and a solid-liquid separation device; the acidolysis reaction tank is a multi-cell square-section reaction tank which comprises reaction rooms from 1 to 6; the reaction room 6 of the reaction tank is connected with a swirler; the outlet at the lower section of the swirler is connected with the large crystal collecting tank, and the outlet at the upper section of the swirler is provided with a pipeline and connected to the acid hydrolysis reaction tank; the outlet of the large crystal collecting tank is communicated with the solid-liquid separation device; the washing water draining pipeline of the solid-liquid separation device is connected to the acid hydrolysis reaction tank. When in use, separation is performed on phosphogypsum crystal slurry with different crystal sizes through the swirler, then large particle crystal enters into the large crystal collecting tank, then solid-liquid separation is performed, and then fine particles are used for growing the grain with novel slurry after entering into the acid hydrolysis reaction tank. After the adoption of the invention, the phosphorus yield is improved, meanwhile, filtering for washing water for washing is facilitated, and the capability of the filtering equipment is enhanced.

Description

technical field [0001] The invention relates to phosphoric acid, in particular to a device and method for phosphoric acid production. Background technique [0002] Control calcium sulfate to dihydrate (gypsum) CaSO when phosphate rock reacts with sulfuric acid in wet-process phosphoric acid production process 4 .2H 2 The process of O form precipitation is called dihydrate process. [0003] The production process of wet-process phosphoric acid in the prior art is: react phosphoric acid concentrate and sulfuric acid in the acidolysis reaction tank to generate phosphoric acid slurry; the phosphoric acid slurry coming out of the acidolysis reaction tank directly enters vacuum filtration and separation regardless of the order of the layers. The device performs solid-liquid separation, the separated liquid phase is finished phosphoric acid, and the solid phase is phosphogypsum; the separated solid phase phosphogypsum is washed twice and then discharged. The washing solution of ...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this process is that the phosphoric acid slurry coming out of the acid hydrolysis tank directly enters the filtration and separation device regardless of the level, which brings many adverse consequences.

The main performance is that the slurry is affected by the reaction conditions and some of the slurry crystals are fine, and the fine crystals are easy to block the pores of the filter cloth and the channel of the filter residue layer or penetrate the filter cloth during filtration, resulting in poor washing effect of phosphogypsum and phosphorus The yield is low and affects the filtration strength, resulting in reduced filtration production capacity, high production costs, and increased moisture in gypsum.

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