Production method of monopotassium phosphate with by-product welsh onion special fertilizer

Abstract

The invention relates to the technical field of chemical industry, and in particular to a production method of monopotassium phosphate with a by-product welsh onion special fertilizer. Coefficients such as temperature in a wet process for preparation of monopotassium phosphate are changed to improve the purity of monopotassium phosphate product and to produce a compound fertilizer containing N, P and K in combined state; and a filtrate is adjusted into an acidic state, and is added into a formaldehyde solution to prepare a controlled release compound fertilizer. The method can improve the purity of monopotassium phosphate, besides the produced welsh onion special fertilizer has good absorption rate; and the produced welsh onion special fertilizer meets the nutritional needs of each period in the growth cycle, greatly increases welsh onion yield, and is a high efficient compound fertilizer.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a production method for preparing special fertilizer for green onions by-product of potassium dihydrogen phosphate. Background technique [0002] Potassium dihydrogen phosphate is widely used in almost all types of crops such as various types of economic crops, grain, melons and fruits, vegetables, etc. It has the effect of overcoming the nutrient deficiency caused by the aging and absorption capacity of the root system in the later stage of crop growth. It is a new type of high-concentration phosphorus and potassium two-element compound fertilizer, and it is an efficient phosphorus and potassium compound fertilizer in agriculture. At present, many domestic fertilizer manufacturers are producing potassium dihydrogen phosphate compound fertilizer. The production methods mainly include neutralization method, extraction method, ion exchange method, metathesis method, direc...

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Problems solved by technology

[0013] The unabsorbed mixed fertilizer is easy to cause soil compaction. At the same time, the release and loss of the mixed fertilizer is too fast, which will cause the scallions to grow wildly in the early stage. In the later stage, the scallions will grow wildly and the nutrients in the soil will not be able to supply the scallions due to rainwater soaking or fertilizer self-decomposition. needs, causing the growth of scallions to slow down or stop

[0014] In the process of producing potassium dihydrogen phosphate from wet-process phosphoric acid, the purity of potassium dihydrogen phosphate is not high, and the filtrate also contains a large amount of unprecipitated carbonamide, K + 、H 2 PO 4 - 、HPO 4 2- 、PO 4 3- and other substances, the researchers of the present invention have studied the composition content of traditional scallion special fertilizer and the absorption situation of scallions from a large amount of prior art documents and years of exploration and research, and have effectively explored the production of phosphoric acid diphosphate from wet-process phosphoric acid. The special fertilizer for scallions is produced from the filtrate of potassium hydrogen phosphate, which solves the problems of low purity of potassium dihydrogen phosphate produced by wet-process phosphoric acid and unusable active ingredients in the filtrate. At the same time, the special fertilizer has good absorption rate and controllable release effect. Domestic fertilizer production, no report

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