Wet phosphoric acid production process through ceramic membrane method

Abstract

The invention relates to a wet phosphoric acid production process through a ceramic membrane method. The wet phosphoric acid production process is characterized in that crude phosphoric acid filtered by a filter is pumped into a ceramic membrane separation system to be filtered, so that suspended matter in the crude phosphoric acid is removed, and clarified and transparent diluted phosphoric acid is obtained; and a ceramic membrane concentrated solution returns into the filter to circulate and is discharged along with gypsum filter residues. Compared with a conventional wet phosphoric acid production process, the wet phosphoric acid production process provided by the invention has the characteristics that the crude phosphoric acid filtered by the filter is not aged and clarified and directly enters the ceramic membrane separation system to be filtered, and therefore, the technological process and the crude phosphoric acid processing time are shortened; furthermore, a flocculating agent is not needed in the treating process; and, after the crude phosphoric acid is filtered, the solid content in the crude phosphoric acid is reduced to 0.01 wt% and below. The wet phosphoric acid production process disclosed by the invention can effectively solve the technical problems of long technological process and crude phosphoric acid processing time and low suspended matter removing efficiency in the traditional wet phosphoric acid production process; simultaneously, the ceramic membrane separation system in the invention is simple in equipment and small in occupation area; and continuous operation can be realized.

Description

Technical field

[0001] The invention relates to a phosphoric acid production process and a membrane separation technology, in particular to a ceramic membrane wet process phosphoric acid production process, belonging to the chemical industry. Background technique

[0002] Phosphoric acid production methods mainly include wet-process phosphoric acid and thermal phosphoric acid, of which wet-process phosphoric acid production processes account for more than 90%. According to the different grades of phosphate rock and the fluctuation of production conditions, the concentration of crude phosphoric acid produced by wet-process phosphoric acid is 20wt%~30%wtP 2 O 5 between.

[0003] The production process of wet-process phosphoric acid is as follows: Phosphate rock and sulfuric acid are reacted in the acidolysis reaction tank to generate phosphoric acid slurry. The slurry from the acidolysis reaction tank is pumped into a vacuum filter through a slurry pump for solid-liquid separation. ...

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