SU870390A1 - Method of producting complex fertilizer - Google Patents

Description

(54) METHOD OF OBTAINING COMPLEX FERTILIZER

The invention relates to a technique for the production of complex aeotonic fertilizers through the sweat processing of natural phosphates. Methods are known for the preparation of nitro, phosphates by nitric acid technology with the precipitation of calcium by mmonium sulfate (located in recycling), which are varieties of the method of hundred micarbon. The essence of the process is decaying in the decomposition of natural phosphate with nitric acid (47-65% HNO), followed by the binding of calcium ions to calcium sulfate with a 38-40% solution of ammonium sulfate. After the separation of phosphogypsum, which is converted into ammonium sulfate, the filtrate is processed into fertilizer by neutralization with gaseous ammonia, evaporation and drying of the pulp l. The disadvantage of the known nitrogen-sulfate method is the high content of nitrogen in fertilizer with respect to phosphorus pentoxide (1.8-2: 1), while in the most common fertilizer grade the ratio is Isl. This is due primarily to the use of a large amount of nitrogen in the process. 1 Pl Pa 1 11 "/ - PE". GL. .. /. raw materials) required for the complete decomposition of phosphate minerals. The closest to the proposed method in terms of essential features and positive effect is the method of obtaining complex fertilizer by decomposing phosphate raw material with 55% nitric acid (100% of stoichiometry on CaO raw material) in the presence of a working solution / mixture of phosphoric acid and ammonium nitrate, stretching with 40% ammonium sulphate at 28-. З4с, filtration of the pulp with the separation of phosphogypsum (calcium sulfate dihydrate) and the processing of the solution into the finished product by ammoniation, packing of the pulp and drying. The degree of decomposition of the raw material is 99% 2. The disadvantages of this method include the duration of the decomposition process of the phosphate raw material, the high consumption of nitric acid and ammonia gas in the production of nitroammophos, as well as the high content of nitrogen in fertilizer with respect to phosphorus pentoxide. intensification and cheapening of the process by reducing the duration of decomposition, reducing the consumption of nitric acid and gaseous ammonia while maintaining a high degree of decomposition of phosphate raw materials and chsheni quality product. The goal is achieved in the well-known method, which includes decomposition of phosphate raw materials with nitric acid and working solution, treatment of the extract, ammonium sulfate, filtration with separation of calcium sulfate dihydrate and processing the solution in, the finished product by ammoniation, evaporation of pulp and drying, 60 -80% of the phosphate raw material is decomposed with nitric acid in the amount of 85-g95% of the total, but for all-phosphate raw materials within 15-30 mic, and the remaining phosphate raw material is recycled for 30-60 min at B-0 C with subsequent displacement of the vent when o ammonium sulphate at the same time for 60–90 min. The difference of the proposed method consists in the separate decomposition of the part of the phosphate raw material with nitric acid (60-80% of the total mass) and the rest of the working solution. Nitric acid is taken in the amount of 85-95% of the full rate for all phosphate raw materials. The decomposition of nitric acid are within 15-30 minutes The decomposition of the working solution is carried out at 60-80. within 60-90 minutes This difference makes it possible to reduce by 5–15% the consumption of nitric acid (up to 85–95% instead of 100% of stoichiometry on CaO in the known method). Accordingly, the NtPnOj ratio in fertilizer is reduced to 1.5-1 / 58 instead of 1.7-8: 1. In addition, due to the rate of nitric acid when it decomposes part of the phosphate feedstock (150% of the stoichiometry on the CaO feedstock, the decomposition process proceeds at a faster rate. The time and temperature intervals for carrying out the proposed process are associated with the complete decomposition of the phosphate component of the feedstock reduced consumption of nitric acid. Table 1 shows the results of the comparison of the indicators of the proposed and well-known methods. Table 2 shows the data confirming the receipt of a positive effect at 11% process in the proposed range of parameters (approx | gras 1-3). From Table 2 it can be seen that when the values of the parameters go beyond the predalegam are 4-15, the degree of decomposition of the raw material decreases or the process is i-feasible Example: As a raw material, Eno-Kavdor apatite concentrate of composition is used, May.%: Pj, 8, CaO 40.5; MgO 4.4; n / O 3.2. 80 kg I apatite concentrate (80% of the total mass ) decompose 207 kg of 50% nitric acid {HNOj standard - 95% of the total norm on the total phosphate feedstock) 3 for 15 min. The remaining 20 kg of apatite decompose 300. kg of working solution (2.5 mol HjPG 9.5 mol NHx.N05. And 0.5 mol NH4H2 PO) for 30 minutes. After mixing the extracts (1607 kg), they are processed with 258.8 kg of 40% ammonium sulfate solution and incubated for 60 minutes. The pulp is filtered with the separation of 215.8 kg of calcium sulfate — washed with 100 kg of water and sent for conversion to ammonium lofate. The filtrate in the amount of 750 kg is divided into two streams: 300 kg is used to decompose part of the phosphate raw material, and 450 kg ammonize 8.0 kg of ammonia. Ammonized pulp (450 kg) is evaporated to remove 158 kg of water. 300 kg of one stripped off pulp is mixed with 56.6 kg of CS) (60%) and dried. After removing 143.6 kg of water, 213 kg of a 25.3: 16: 16 nitroammofoski product is obtained. Ratio it is 1.58: 1. In this case, the consumption of nitric acid per 1 ton of product is 0.16 tons less than in the known method. The degree of decomposition of phosphate raw materials is 99%. PRI mme R 2. 60 kg of apatite concentrate (60% of the total mass) decompose 185.4 kg of 50% nitric acid (the norm is 85% of the total norm for all phosphate raw materials) within 30 min. The remaining 40 kg of apatite 300 kg of a working solution (mol, 8.5 mol of MNFYO3 and 1.5 mol) are decomposed at 80 ° C for 60 minutes. After displacing the extracts (585.3 kg), they are treated with 258.8 kg of a 40% ammonium sulfate solution and incubated for 90 minutes. The pulp is filtered with the separation of 214.1 kg of calcium sulphate, washed with 100 kg of water, and sent for conversion to ammonium sulphate. The filtrate in the amount of 730 kg is divided into two streams: 300 kg is used to decompose part of the phosphate raw material, and 430 kg of rmonium-ionize 7.6 kg of ammonia. Ammoniated pulp (437.6 kg) is an outparine with removal of 137.6 kg of water. 300 kg of one stripped off pulp is mixed with 56.6 kg Ktn (60% K, s, 0) and dried. After the removal of 143.6 kg of water, this gives 213 kg of the product - a nitroammophotic composition: 24.1: 16: 16. The ratio M: R, .Oh in it is 1.51: 1. At the same time, the consumption of nitric acid per 1 ton of P2.05-product is 0.32 t-less than in the known method. The degree of decomposition of the raw material is 99. Example 3.70 kg of apatite (101 of the total mass) decompose 196.2 kg of 50% nitric acid (the norm is 90% of the total norm for all phosphate raw materials) within 20 minutes. The remaining 30 kg of apati / a decompose 300 kg of a working solution of 2 mol. Emol. ННдЫО} and 1.0 mol at 45 minutes. After mixing the extracts (596.2 kg), they are treated with 258.8 kg of a 40% sulphate solution and dried for 75 missions. The pulp is filtered with a separation of 215.0 kg of sulphate washed with 100 kg of water and sent for conversion to ammonium sulphate. The filtrate in the amount of 740 kg is divided into two streams: 300 kg is used to decompose part of the phosphate raw material, and 440 kg are ammoniated. 7.8 kg of ammonia. Ammonized bullets, pu (447.8 kg) evaporated with removal

Continuing decomposition, min:

nitric acid

Circulating solution

Pyrma NNO,% of stoichiometry

Amount of HNOj per 1 l of raw material, t

Ratio

,

in fertilizer

Table 1

120-150

100 .1.09

l, 6-l, 8tl 147/8 kg of water, 300 kg of evaporated pulp are mixed with 56.6 kg of KC1 (60%) and dried. After the removal of 143.6 kg of water, half a century of 213 kg of the product - a nitroammophotic compound of 24.6 tl6tl6. Ratio 4 1.54 (1. At the same time, the consumption of nitric acid per 1 ton of PJLO product is 0.24 tons less than in the known method. The degree of decomposition of phosphate raw materials is 99% .. as a result of the proposed method of obtaining more balanced nitrogen fertilizer with simultaneous intensification and cheapening of the process when preserving a high degree of decomposition of phosphate raw materials.

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 the invention

A method of obtaining a complex fertilizer, which includes decomposition of phosphate raw materials with nitric acid and circulating solution, treating the extract with ammonium sulfate, filtering with the separation of calcium sulphate and processing the solution into the finished product by ammoniation, packing and drying, about tl and h that with the aim of intensifying and cheapening the process by reducing the duration of decomposition, reducing the consumption of nitric acid and ammonia gas while maintaining a high degree of decomposition

phosphate raw materials and improving product quality, 60-80% of phosphate raw materials decompose with nitric acid in the amount of 85-95% of the total norm for all phosphate raw materials within 15-30 minutes, and the remaining phosphate raw materials - with a working solution for 30-60 minutes with BWO, followed by mixing the extracts with simultaneous feeding of ammonium sulfate for 60-90 minutes

Sources of information taken into account in the examination

1.Pozin M.E. Mineral salt technology. 4.11, 1975, p.1307.

2. US Patent 2689175, cl. 71-39, 1954 (prototype).

Claims (1)

Claim A method of producing a complex fertilizer, including the decomposition of phosphate raw materials with nitric acid and a circulating solution, processing the extract with ammonium sulfate, filtering with separation of calcium sulfate and processing the solution into a finished product by ammonization, evaporation and drying, characterized in that in order to intensify and reduce the cost process by reducing the duration of decomposition, reducing the consumption of nitric acid and gaseous ammonia while maintaining a high degree of decomposition '(5 phosphate raw materials and improving product quality, 60-80% of the phosphate raw material is decomposed with nitric acid in an amount of 85-95% of the full norm for all phosphate raw materials for 15-30 minutes, 1a of the remaining phosphate raw material - with a circulating solution for 30-60 minutes at 60-80 ^fl C followed by mixing hoods while feeding ammonium sulfate for 60-90 minutes