Method for producing spray organic and inorganic composite fertilizer from middle-and-low-grade phosphate ore

Abstract

The invention relates to a method for producing spray organic and inorganic composite fertilizer from middle-and-low-grade phosphate ore. The middle-and-low-grade phosphate ore is added to a crusher for coarse crushing firstly, the coarsely crushed middle-and-low-grade phosphate ore enters a ball mill, meanwhile, water and a dispersing agent are added to the ball mill, the middle-and-low-grade phosphate ore is ball-milled to form ore pulp, the ore pulp is pumped into an extraction tank for extraction, phosphoric acid is prepared, and the extraction rate of the phosphate ore is detected; phosphoric acid and potassium hydrogen sulfate produced with a low-temperature transformation method are pumped into a tubular reactor by a pump to be neutralized with liquid ammonia, neutral slurry is obtained, an organic raw material is added to the neutral slurry and evenly stirred, slurry is obtained and subjected to spraying granulation, drying, screening and packaging, and the spray organic and inorganic composite fertilizer produced from the middle-and-low-grade phosphate ore is obtained. According to the method, the dispersing agent is added, so that the extraction rate of the phosphate ore is effectively increased, the extraction time is saved, and the production efficiency of the composite fertilizer is improved.

Description

technical field [0001] The invention relates to a method for producing sprayed organic-inorganic compound fertilizer by using medium and low-grade phosphate rock. Background technique [0002] my country's phosphate rock reserves are large, ranking second in the world. It is characterized by less rich ore and more low-grade ore. However, in recent years, due to the increase in the output of high-concentration compound fertilizers, the phosphate rock with a content of more than 30% has become increasingly tense. However, in my country's traditional dihydrate method to produce phosphoric acid, it is necessary to use P 2 o 5 ≥30% high-grade ore, the extraction rate can reach more than 99%, P 2 o 5 ≤30% low-grade phosphate rock, because it contains more impurities, if it is directly extracted, the extraction rate is generally lower than 96%, and the extracted phosphoric acid content is low, resulting in waste of resources. Direct drying requires a lot of coal consumption, an...

AI Technical Summary

Problems solved by technology

However, in my country's traditional dihydrate method to produce phosphoric acid, it is necessary to use P 2 o 5 ≥30% high-grade ore, the extraction rate can reach more than 99%, P 2 o 5 ≤30% low-grade phosphate rock, because it contains more impurities, if it is directly extracted, the extraction rate is generally lower than 96%, and the extracted phosphoric acid content is low, resulting in waste of resources. Direct drying requires a lot of coal consumption, and The content of phosphoric acid is low, and the production of fertilizers is also limited; the medium and low-grade phosphate rock needs to be purified by flotation before it can be used

At present, there is no method to improve the extraction rate by directly extracting low- and medium-grade phosphate rocks