SU1666454A1 - Method for manufacturing complex fertilizer - Google Patents

Abstract

The invention relates to the production of mineral fertilizers and makes it possible to produce complex fertilizers from substandard phosphate raw materials — agglomeration phosphorite dust with a P ₂ O ₅ content of at least 17% and phosphorite obtained in the sintering process. The method is carried out by decomposing phosphate raw materials with extractive phosphoric acid with a cation sum of not more than 3.0% and a P ₂ O ₅ concentration of not less than 18%, taken in the amount of 89–104% of stoichiometrically necessary, followed by neutralization of the pulp with ammonia to the molar ratio NH ₃ : H ₃ PO ₄ = (0.5 - 1.0): 1 and drying the product. The finished product contains, wt%: P ₂ O _{5 total} 38 - 39

P ₂ O _5usv 33.9 - 36.5

P ₂ O _5water 26 - 26.9

N 4.0 - 5.3. 4 tab.

Description

possible.

Example 3 Under the conditions analogous to example 1, the product is obtained, changing the amount of extracted phosphoric acid.

The dependence of the quality of the fertilizer on the amount of phosphoric acid supplied is given in Table 2.

Thus, for the optimal amount of acid supplied, 89-104% of the stoichiometrically necessary is to be taken, since this ensures the quality of the fertilizer that meets the requirements of the DUT to the amount of nutrients.

When the acid rate decreases, the nutrient content in the fertilizer decreases, and when it increases, the content of the water-soluble form of PaOs increases significantly, which degrades the properties of the product.

Example 4 Under the conditions analogous to example 1, a fertilizer is obtained, the molar ratio 1CHNz: HzP04.

The dependence of the quality of the fertilizer on the molar ratio of MH3: HzR04 is shown in Table 3.

As follows from Table 3, the optimal ratio of MP: NZR04 should be taken (0.5-1.0) .1. As the ratio changes in the direction of decreasing the amount of ammonia, the physical properties of the product deteriorate. The fertilizer is made hygroscopic and manageable, which is explained by the presence of free acid. A change in the ratio in the direction of increasing the amount of ammonia results in a non-conforming product (the nitrogen content increases and the indicators decrease.

P205 general and P205vod).

Example 5. Under conditions analogous to example 1, a fertilizer is obtained by supplying sinter phosphorite dust of different composition to decomposition.

The results of the experiments are shown in table 4.

As can be seen from the data of Table 4, using agglomerative phosphorite dust with a Ra content of just below 17%, a product is obtained that does not comply with TU 113-08-552-84 in terms of the content of the main components.

The proposed method, in comparison with the prototype, makes it possible to obtain a conditional complex fertilizer from waste phosphorus production - sinter phosphorus dust with a PzOs content of at least 17%.

Using the method provides a reduction in the cost of the finished product.

Claims (1)

Invention Formula A method of obtaining a complex fertilizer, which includes decomposition of phosphate raw materials by extraction phosphoric acid, followed by neutralization of the obtained pulp with an ammonia-containing component, drying the product, characterized in that, in order to create the possibility of processing sinter phosphorite dust with a PaOs content of at least 17% and obtained during the process of agglomeration of phosphate, phosphoric acid with a PaOs concentration of at least 18% and a cation amount of no more than 3.0% in the amount of 89-104% of the stoichiometric required, and a neutr is fed to decomposition tion of ammonia gas lead to a molar ratio of NH3: H3P04 (0,5-1.0): 1. Table 1 table 2 Table 3 Table 4