The invention relates to the technical field of
chemical industry, and particularly relates to a production method for preparing
tripotassium phosphate and by-producing a special
fertilizer for litchi. According to the production method, the effective absorption amount of
nitrogen,
phosphorus and
potassium elements is analyzed according to the
fertilizer requirement of litchi, and element content is regulated and collocated in a production process course, so that a prepared compounded-form compound
fertilizer can furthest meet the requirement of the litchi, excessively high cost caused due to improper element
collocation in the production of the compound fertilizer is reduced, and environmental
pollution caused by that the compound fertilizer is solidified by adding excessive elements to soil is further prevented; and the
impurity removal cost needed when a
tripotassium phosphate product is prepared by adopting the traditional wet-process
phosphoric acid method is made up, so that the purity of the prepared
tripotassium phosphate product reaches more than 95%, the production cost is reduced by 93%, and outstanding economic benefit is achieved.