Production method for preparing monopotassium phosphate and coproducing special fertilizer for capsella bursa-pastoris

Abstract

The invention relates to the field of chemical technologies, and particularly relates to a production method for preparing monopotassium phosphate and coproducing a special fertilizer for capsella bursa-pastoris. Through carrying out research and analysis on the requirements on the contents of nutritional ingredients in capsella bursa-pastoris and carrying out regulation and collocation on the contents of elements in the technological process of production, a prepared combined compound fertilizer can maximally meet the demands of crops, so that a situation that the cost is too high due to improper element collocation in the production of the compound fertilizer is reduced, and a situation that the compound fertilizer solidifies the soil and then pollutes the environment because excessive elements are put into the soil is further avoided.

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 potassium dihydrogen phosphate by-product shepherd's purse. Background technique [0002] After the common fertilizer is applied to the cultivated land, part of it will be transpired, dissipated and lost with water, part of it will be fixed and utilized by the soil and soil microorganisms, and only part of it will be absorbed and utilized by the crops. Studies have shown that: the utilization rate of urea and ammonium bicarbonate is 20% to 46%, phosphate fertilizer (diammonium, monoammonium, heavy calcium) is 10% to 25%, and potassium fertilizer is 45% to 60%. It can be seen that the utilization rate of ordinary fertilizers is very low. [0003] Through the analysis of the requirement of shepherd's purse macronutrient elements and the research on the nutrient content of traditional nitrogen, phosphorus and potass...

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Problems solved by technology

[0003] Through the analysis of the requirement of shepherd's purse macronutrient elements and the research on the nutrient content of traditional nitrogen, phosphorus and potassium compound fertilizers, it can be known that the nitrogen, phosphorus and potassium required by shepherd's purse for traditional compound fertilizers are 16% nitrogen, 7% phosphorus, and 7% potassium , the total amount reaches more than 30%. Therefore, the effective absorption capacity of nitrogen, phosphorus and potassium elements of NPK compound fertilizer is 3.2-7.5%, the effective absorption capacity of phosphorus is 0.7-1.75%, and the effective absorption capacity of potassium fertilizer is 3.15-4.2%; it can be seen that the simple combination and collocation of traditional NPK compounds will cause a large amount of NPK nutrients to be left in the soil, which will be transformed and lost by the soil for a long time, which will lead to the loss of NPK nutrients. The elements harden the soil and pollute the environment, wasting natural resources

[0004] In addition, in the preparation process of potassium dihydrogen phosphate products, cooling and crystallization treatment is usually adopted, so that the potassium dihydrogen phosphate product in the raw material liquid reaches a saturated state and then is crystallized, while in the traditional production process of potassium dihydrogen phosphate In order not to waste resources such as potassium dihydrogen phosphate contained in the raw material liquid, potassium dihydrogen phosphate is often subjected to cyclic crystallization treatment, so that the potassium dihydrogen phosphate in the raw material liquid is precipitated by a large amount of crystallization, thereby improving the product quality of potassium dihydrogen phosphate Yield; But, the purity of the potassium dihydrogen phosphate product prepared according to the above method is lower, because, when potassium dihydrogen phosphate thoroughly crystallizes out, in the process of the potassium dihydrogen phosphate product prepared by wet-process phosphoric acid or hot-process phosphoric acid Contains a large amount of chemical elements such as calcium, magnesium, aluminum, iron, etc., and at the same time that potassium dihydrogen phosphate is completely crystallized, other metal phosphates or dihydrogen phosphate will be crystallized at the same time, which greatly reduces production. The purity of the potassium dihydrogen phosphate product, for this reason, a separation and filtration process will be added to purify the potassium dihydrogen phosphate product, which will greatly increase the cost of preparing the potassium dihydrogen phosphate product

[0005] At the same time, for the preparation of compound fertilizer products, it is generally obtained by mixing a variety of organic or inorganic compounds in the traditional process, and the composition content of various compounds is adjusted according to the needs of crop nitrogen, phosphorus and potassium nutrients. In order to ensure that the nutrient elements that meet the growth of certain crops can be provided, but in the process, a large amount of nitrogen, phosphorus, and potassium elements will be lost in the soil due to the unreasonable combination of elements, making the soil harden, wasting natural resources and polluted environment

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