Ammonium phosphate slurry filter unit and filter method thereof

Abstract

The invention relates to the field of an ammonium phosphate slurry filter technology, especially to an ammonium phosphate slurry filter unit and a filter method thereof. according to the invention, pH value, temperature, ammonium phosphate ratio and solid content of the ammonium phosphate slurry which enters the filter unit are defined to ensure that a liquid can rapidly infiltrate into the inside of a filter bag to support the filter bag after the ammonium phosphate slurry enters the filter unit; by the combination of aeration reverse osmosis filtration treatment, a filtrate can effectively enter the filter bag to leave impurities on the external surface of the filter bag; and by the combination of bag dumping treatment and cleaning treatment, the filter bag is regenerated. In addition, filtration difficulty due to high viscosity of the filtrate is avoided, purity of ammonium phosphate in the filtrate is raised, and quality of the ammonium phosphate product is fully ensured.

Description

technical field [0001] The invention relates to the technical field of ammonium phosphate slurry filtration, in particular to an ammonium phosphate slurry filtration device and a filtration method thereof. Background technique [0002] During the static settling process of dihydric wet-process phosphoric acid, a large amount of solid sedimentation slag will be precipitated, and the main components of the slag are phosphogypsum and (Fe, Al) 3 K H 14 (PO 4 ) 8 4H 2 O complexes also contain a large number of soluble impurities, such as magnesium ions, calcium ions, iron ions, aluminum ions, sulfate radicals, fluorosilicate radicals, etc.; during the neutralization reaction between wet-process phosphoric acid and ammonia, these impurities will A variety of complex compounds are generated, which seriously affect the viscosity of ammonium phosphate slurry and the product composition, physical properties and solubility of phosphorus pentoxide of ammonium phosphate slurry. Ther...

AI Technical Summary

Problems solved by technology

[0003] There are three main traditional filtration methods for ammonium phosphate slurry, gravity settling, centrifugal separation, and filter filtration; while gravity settling requires huge supporting equipment, high investment and operation and maintenance costs, and fine solids in high-viscosity ammonium phosphate slurry The insoluble matter is not easy to settle quickly. In addition, during the gravitational settling process of the solid insoluble matter, the ammonium phosphate salt crystals will be precipitated due to the decrease of the slurry temperature, which will affect the utilization rate of the ammonium phosphate slurry; The relatively high and highly viscous ammonium phosphate slurry can easily block the centrifugal rotating parts; the filter equipment is currently mainly a plate and frame filter press and a belt filter, etc. The filters are intermittently operated, the device is switched frequently, and the filter cloth is cleaned. Inconvenient, for filtering ammonium phosphate slurry containing a certain amount of silica gel, the equipment operating rate is extremely low

[0004] This shows that the ammonium phosphate slurry filtration method in the prior art has many defects, and it is difficult to ensure that the utilization rate of the ammonium phosphate slurry is high, and the quality of the ammonium phosphate salt product can be improved, which hinders the wet process. The development of direct preparation of fine ammonium phosphate products from phosphoric acid

Images