Granular compound fertilizer produced by utilizing phosphoric acid residue and production method of granular compound fertilizer

Abstract

The invention relates to granular compound fertilizer produced by utilizing phosphoric acid residue and a production method of the granular compound fertilizer. The production method comprises the steps of preparation of a urea-sulfuric acid solution, phosphate ore decomposition, neutralization, granulation and the like. According to the production method disclosed by the invention, urea-sulfuricacid is utilized, and phosphate ores can be decomposed, so that emission of phosphogypsum can be reduced; meanwhile, insoluble phosphorus in the phosphoric acid residue can also be activated, the content of effective phosphorus in ore pulp accounts for 99 percent or above of total phosphorus, the problem of acid residue utilization of a large-scale phosphorus fertilizer enterprise can be solved, comprehensive utilization of resources is realized, and the economic benefit of the enterprise is increased; compared with common compound fertilizer, by applying the granular compound fertilizer produced by the method, the fertilization amount can be saved by 20 percent or above, and national chemical fertilizer-pesticide double-reduction policy and a strategic direction of national sustainable development are fitted.

Description

【Technical field】 [0001] The invention belongs to the technical field of fertilizer production. More specifically, the present invention relates to a granular compound fertilizer produced by utilizing phosphoric acid slag acid, and also relates to a production method of the granular compound fertilizer. 【Background technique】 [0002] ZL 2005 1 0106021, Invention title "Manufacturing method of clean urea-sulfuric acid compound fertilizer" Technology uses urea water reduction method, under the action of activator, decomposes phosphate rock with urea-sulfuric acid solution to produce slow-release nitrogen and phosphorus with different nutrient contents (or potassium) special compound fertilizer, which greatly shortens the production cycle, greatly simplifies the fluorine recovery system, and has no "three wastes discharge". It is a clean process that meets the requirements of circular economy. ZL 2013 1 0096516, the invention name "a production method of urea-sulfuric acid mu...

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Problems solved by technology

[0003] Most of the monoammonium phosphate or diammonium phosphate production processes of large-scale phosphate compound fertilizer enterprises in my country use the dihydric method to extract phosphoric acid, but the concentration of phosphoric acid produced by the dihydric phosphoric acid process is low, and it needs to be concentrated to P 2 o 5 The content is more than 45% by weight. During the concentration process, sludge acid (referred to as slag acid) will be produced. It contains a large amount of solid-phase acid-insoluble matter, usually with a content of 15% to 25% by weight. This part of the solid phase P 2 o 5 The content is higher, but this part of P 2 o 5 It is insoluble and cannot be absorbed by crops; slag acid cannot be directly used in the production of high-concentration diammonium phosphate, monoammonium phosphate, and double superphosphate, and it is difficult to handle, so it is usually used to produce low-concentration products with low economic benefits Monoammonium phosphate, or export at low price

At the same time, during the production process of the existing high-concentration phosphate fertilizer, the discharge of phosphogypsum is also a major problem for enterprises

[0004] my country's large-scale heavy superphosphate production adopts the slurry method, but because it needs to produce high-concentration concentrated phosphoric acid first, and requires the use of high-quality phosphate rock raw materials, the production cost of the product is high, the product structure is single, and the economic benefits are not good. , some enterprises have carried out multi-functional technical transformation on the heavy calcium plant, so that the plant has the ability to produce heavy calcium, calcium-enriched, granular monoammonium phosphate, and granular diammonium phosphate products of different specifications; The available technology and equipment status are relatively close to the production process technology of urea-sulfuric acid compound fertilizer. Only a small amount of technical transformation has been carried out on the production process of the heavy calcium plant, a small amount of equipment has been added, and at the same time, the NPK project has been improved and repaired, so that the urea-sulfuric acid compound fertilizer can be realized. Production of Slurry Heavy Calcium Plant

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