Method for preparing feed grade calcium hydrogen phosphate co-production water glass by using slag acid and yellow phosphorus slag

Abstract

The invention discloses a method for preparing feed grade calcium hydrogen phosphate co-production water glass by using slag acid and yellow phosphorus slag. It uses slag acid from the phosphoric acid industry as the raw material to leach yellow phosphorus slag, and then crystallizes out feed-grade calcium hydrogen phosphate, which meets the requirements of the national standard GB / T22549-2008. The filtrate containing silicic acid and impurities is added Sodium hydroxide solution is reacted for a period of time to obtain water glass, which is used as an inhibitor of phosphate rock flotation, and the phosphate concentrate after positive and negative flotation meets the raw material requirements for the production of wet-process phosphoric acid by the dihydrate method. The method disclosed by the present invention utilizes slag acid and yellow phosphorus slag to prepare feed grade calcium hydrogen phosphate to co-produce water glass. It is also of great significance from an environmental point of view.

Description

technical field [0001] The invention particularly relates to a method for preparing feed grade calcium hydrogen phosphate co-production water glass by using slag acid and yellow phosphorus slag. It belongs to the field of phosphorus chemical industry and phosphorus ore dressing production. Background technique [0002] Yellow phosphorus slag is a solid waste produced when industrial yellow phosphorus is produced in a high-temperature electric furnace with phosphate rock, silica, coke, etc. as raw materials. The main minerals are wollastonite, lancetite, wollastonite and calcium silicate The main component is calcium silicate, and it also contains a small amount of aluminum, iron, magnesium, phosphorus, fluorine and other elements. At present, the world's yellow phosphorus production capacity exceeds 1600kt / a; there are more than 150 yellow phosphorus production enterprises in my country, more than 300 phosphorus electric furnaces, and the national yellow phosphorus producti...

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Problems solved by technology

There are big problems in this process: ①Industrial wet-process phosphoric acid and nitric acid make the process cost high; ②Phosphoric acid and yellow phosphorus slag react to produce silicic acid, which is difficult to filter and difficult to industrialize; ③The amount of filtered waste liquid is large and difficult to treat. The whole process is very costly

[0003] With the large-scale mining and utilization in recent years, the quality of calcareous phosphate rock has been declining, and a large number of low-grade siliceous and mixed collophosite have not been effectively developed and utilized.

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