Production method of feed-grade granular calcium hydrogen phosphate III-type product

Abstract

The invention relates to a production method of a feed-grade granular calcium hydrogen phosphate III-type product, which comprises the following steps of: mixing strong phosphoric acid with 30-50 wt% of phosphorus pentoxide and a calcium-containing compound according to the Ca / P ratio of 0.75-0.85 in a reactor at high rotating speed greater than and equal to 450 RPM for reaction, continuously feeding produced mixed slurry containing calcium hydrogen phosphate and monocalcium phosphate together with a return material into a mixing granulator for granulation, and feeding a produced feed-grade granular calcium hydrogen phosphate III-type moisture semi-finished product into a drying machine for drying; and screening a dried finished product output by the drying machine to obtain the calcium hydrogen phosphate III-type product, and crushing tailings remained after screening and returning the crushed tailings to the mixing and granulation steps as the return material. With the production method, the feed-grade granular calcium hydrogen phosphate III-type product is directly synthesized in one-step reaction, the production method has low grade requirement for raw materials, short production process flow and high phosphorus utilization rate, and no white fertilizer or waste water is produced; and the granular product does not cake and has good flowability, and the biological value of animals is high.

Description

technical field [0001] The invention relates to a method for producing calcium hydrogen phosphate products, in particular to a production method for producing feed-grade granular calcium hydrogen phosphate type III products. Background technique [0002] Feed-grade calcium hydrogen phosphate type III product is between feed-grade calcium dihydrogen phosphate and feed-grade calcium hydrogen phosphate type I in terms of performance, and its basic composition is calcium hydrogen phosphate and calcium dihydrogen phosphate mineral feed additives. According to the national standard GB / T22549-2008 defines that the above-mentioned products with total phosphorus (P) content ≥ 21.0%, citrate soluble phosphorus (P) content ≥ 18.0%, water soluble phosphorus (P) content ≥ 10% are called feed grade calcium hydrogen phosphate type III product. Since the phosphorus composition contains both water-soluble phosphorus and citrate-soluble phosphorus, it is not only suitable for livestock and ...

AI Technical Summary

Problems solved by technology

This method uses concentrated phosphoric acid to react with calcium oxide, although the process is shorter, but because it is a solid-liquid reaction, the reaction time is long, the reaction is incomplete, the maintenance cost of phosphoric acid defluorination equipment is high, the reaction semi-finished product has a long aging cycle, and the dried product is broken After sieving, the finished particles are irregular

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