Production method for preparing monopotassium phosphate and byproduct special fertilizer for medlar

Abstract

The invention relates to the technical field of chemical engineering and particularly relates to a production method for preparing monopotassium phosphate and a byproduct special fertilizer for medlar. The quality of the produced medlar compound fertilizer is guaranteed by virtue of molar ratio of raw materials in a production process and accurate analysis and detection of the filtrate in a crystallization step, and a waste liquid in the production process of a chemical engineering product is used as a raw material of the medlar compound fertilizer by way of adjusting the content of filtrate components, so that emission of the waste liquid is avoided and the production cost of the compound fertilizer is lowered. Meanwhile, the purity of a monopotassium phosphate product is improved, the production cost of the monopotassium phosphate product is lowered, and the environmental pollution is avoided. The production method has remarkable economic and ecologic benefits.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a production method for preparing potassium dihydrogen phosphate by-product wolfberry special fertilizer. Background technique [0002] Lycium barbarum is a special fertilizer-tolerant perennial woody medicinal and edible economic crop with a long annual growth cycle. From April to early November every year, it will experience flower bud differentiation, branch and leaf growth, flowering and fruiting, and root growth. And other important processes, every process needs to consume a lot of nutrients, and it takes a long time to fertilize. If the supply of nutrients is insufficient or the supply of nutrients is not comprehensive, it will affect the growth of branches and the differentiation of flower buds, and it is easy to Causes a large number of flowers and fruits to drop. Insufficient nutrient supply not only affects the output of the year, but also directly affects t...

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Problems solved by technology

[0003] At present, there are many kinds of compound fertilizers and micro-fertilizers on the market, but they are all lacking in pertinence, and they do not have a clear understanding of the nutrition, growth, growth and fertilization of Lycium barbarum, a crop with distinct regional growth and growth cycle. There are not many technical researches, the fertilizer products developed are single, and the nutrition is not comprehensive, which cannot meet the nutritional needs of wolfberry.

For example, the patent No. CN201310353203.4 "A high-efficiency nitrogen fertilizer containing more than 47% nitrogen and its preparation method" is made by compounding urea, melamine, dicyandiamide, melamine formaldehyde resin and thiourea according to a certain ratio. , and then increase the nitrogen content in the fertilizer, improve the quality of the fertilizer, so as to provide a large amount of nitrogen for the crops to meet the needs of the crops; Limited, and its absorption rate is low, the absorption rate for nitrogen element does not exceed 25%, the absorption rate for phosphorus element does not exceed 40%, and the absorption rate for potassium element does not exceed 60%, so for the traditional composite Fertilizers and chemical fertilizers will have a large amount of nitrogen, phosphorus and potassium remaining in the soil, which is difficult to be absorbed by crops, thereby causing environmental pollution and waste of resources; at the same time, some researchers have also studied the use of wolfberry fertilizers, such as the patent No. CN200510065339.0 "Preparation of Special Fertilizer for Lycium Barbarum and Fertilization Technology", this technology has prepared different fertilizer formulas for different growth stages of Lycium barbarum, and the raw materials of the formula are urea, double superphosphate, and potassium sulfate for mixing, pulverizing, and making It is made of granules, and also provides micro-fertilizers, which are compounded by mixing urea, potassium dihydrogen phosphate, potassium chloride, EDTA, borax, magnesium sulfate, ferrous sulfate, ammonium molybdate, other sulfates and trace element salts It can be seen from this that in the prior art, traditional chemical fertilizers are generally used as fertilizers for wolfberry. Although this fertilizer can meet the needs of wolfberry growth nutrients, it needs to be used every year. Fertilization for many times will make the soil absorb the fertilizer more and more thinner, resulting in damage to the structural layer of the soil, which will affect the ecological environment and cause a large amount of nitrogen, phosphorus and potassium to be wasted

[0004] Furthermore, in the preparation process of potassium dihydrogen phosphate products, it is usually prepared by reacting phosphoric acid and potassium element, and some people use phosphoric acid and urea to react to form urea phosphate, and then use urea phosphate to react with potassium element to prepare potassium dihydrogen phosphate , but the preparation of potassium dihydrogen phosphate by the two preparation methods usually requires the use of deep crystallization to reduce the waste of phosphorus and potassium resources, increase the output of potassium dihydrogen phosphate, and reduce production costs; however, accompanied by deep crystallization, it will also lead to other The precipitation of impurities affects the purity of the potassium dihydrogen phosphate product. In order to improve the purity of the potassium dihydrogen phosphate product, a purification process needs to be added, which leads to an increase in the cost of preparing the potassium dihydrogen phosphate product.

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