SU1648941A1 - Method for obtaining phosphate-potash fertilizer - Google Patents

Abstract

The invention relates to chemical technology, can be used in the high-temperature processing of phosphate raw materials and contributes to an increase in the concentration of nutrients in the finished product. A mixture containing natural phosphate and potassium bifluoride in a ratio of 1: (0.19-0.44) and sand as a flux is heat treated at 1500-1550 ° C. The content of P20z in the finished product is increased by 2 times and additionally potassium ion is introduced. 1 tab.

Description

The invention relates to chemical technology and can be used in the high-temperature processing of phosphate raw materials, in particular, to obtain phosphate-potassium fertilizer.

The purpose of the invention is to increase the concentration of nutrients in the finished product.

The invention is illustrated by the following examples.

PRI me R 1. A mixture comprising 10.00 g of Dzheroysky phosphate, 1.93 g of potassium bifluoride and 2.27 g of silicon dioxide is subjected to high-temperature treatment at 1530 ° С for 10 minutes. The weight ratio of phosphorite to potassium bifluoride is 1: 0.19. The composition of phosphate, wt.%: PaOs 17,6; CaO 45.8; Re20 1.0; 1.5; SOA 14.9; SiOa 7.1, impurities rest.

When this occurs, the formation of phosphorus-potassium fertilizer - potassium metaphosphate composition, wt.%: PzOs 59.7; KAO 39.7; K.SIFeO, 1, trace impurities rest. The yield of the product was 2.86 g. The degree of recovery of the raOz from the mixture was 97.9%.

PRI mme R 2. The mixture, including 10.00 g of phosphate Karatau, 2.68 g of potassium bifluoride

and 2.17 g of silica biaxide, subjected to heating at 1500 ° C for 10 minutes. The weight ratio of phosphorite - potassium bifluoride 1: 0.27.

The composition of phosphate, wt.%: P20s 24.4; CaO 38.4; MD02.4; Rv20z 1.3; HOS = 1.5; 19.5, impurities rest.

The resulting potassium metaphosphate in an amount of 3.85 g has a composition, wt.%: P203 60.0; KAO; KzSiFe 0,08 micro impurity the rest.

The recovery rate is 98.3%.

Example The mixture, including 10.00 g of appatite, 4.39 g of potassium bifluoride and 6.7 g of SI02, is heated at 1550 ° C for 10 min. The weight ratio of apPa- tite is potassium bifluoride 1: 0.44.

The composition of appatite, wt.%: RaOv 40.0; CaO 49.7; ReaOz 0.4: 0.9; S02 0.6, impurities rest.

The resulting potassium metaphosphate in the amount of 6.51 g has a composition, weight. %: P20s59.9, K2039.4; feSiFe 0,1, trace impurities else. The recovery rate of P20 is 98.0%.

fe

About 4 00

2

The table shows the data indicating the advantage of the proposed method over the known,

It follows from the table that the proposed ratio of ratios natural phosphate - potassium bifluoride, 19-0.50) and a temperature of 1500-155 ° C is the optimal technological parameters for achieving the set goal - an increase in the content of nutrient components in fertilizer (Example 6, 9 and-12). The degree of extraction of P20s from the mixture reaches 97.9-98.3% and there is practically no toxic fluorine in the product. The temperature of 1500-1550 ° C is the temperature of complete melting of the charge, which ensures close contact between its components and the possibility of the above chemical processes at high speed, causing a very high degree of extraction of the nutrient components of the charge in the gas phase.

When the process is carried out at a low temperature, the complete charge does not melt and potassium fluoride, which is released by the reaction, reacts only with the surface layer of refractory particles, remaining in excess and interacting with the formation of K2SiFe, which, in turn, contaminates the product . In this case, an insufficient amount of potassium silicate is formed to react with CazP20b, which reduces the release of PaOs to the gas phase in the process (examples 5, 8, and 11).

Increasing the melting temperature of the mixture above 1550 ° C is not economically feasible, since it practically does not affect either the degree of extraction of P20s or the composition of the product (examples 7, 10 and 13).

A reduced consumption of potassium bifluoride compared with the optimum reduces the degree of extraction of P20s, and an increased consumption leads to contamination of the product by a factor (example 2-4 and 14-16). An attempt to conduct the process of obtaining fertilizer using NaF as a component of the charge (by a known method), but with the proposed parameters of the technological regime does not lead to an increase in the concentration of nutrients in the product. First, sodium is not a plant nutrient; secondly, in this case P20b is not extracted into the gas phase in the form of MARS, which is associated with a high melting point of NaF and no effect of NaF with S10 in the solid phase (which is also very refractory) is formed when KHF2 is decomposed after the latter has completely melted, i.e. KF at the moment of formation

is in the melt, which causes the reactions to occur due to the direct contact of the reacting particles in the melt.

Thus, according to the proposed method, the nutrient content is increased (P20e by 2 times), and potassium ion is additionally introduced

Claims (1)

Claim method for producing phosphorus-potassium Fertilizers, including high-temperature processing of the charge, containing natural phosphate, alkali metal fluoride and silicon dioxide, are different because, in order to increase the nutrient concentration in the finished product, potassium bifluoride is used as an alkali metal fluoride at a ratio of natural phosphate - potassium bifluoride, equal to 1: (0,19-0,44), and processing is carried out at 1500-1550 ° C. Table continuation