SU1242486A1 - Method of producing complex fertilizer - Google Patents

Description

The invention relates to the production of complex fertilizers by decomposing natural phosphates with nitric and sulfuric acids and relates to the stage of neutralization of the pulp obtained. The purpose of the invention is to reduce the consumption of phosphorus raw materials by reducing the retrogradation of phosphorus compounds; Example 1. 292.3 kg of apatite concentrate are processed with 346.6 to 56% asbfhbft acid and 206 kg with 93% serlod acid for 40 69 minutes. With stirring, the resulting pulp is neutralized with 48.3 kg of ammonia gas, and then 30% of the mass of ammonia gas is added, i.e. 67.2 kg of ammonia ammonium nitrate to pH 5 (here and in other examples ammonium nitrate ammonia contains,%: NH, 16.6;, 66.8; 16.6. The vapor pressure over it is 1.07 atm. Neutralized the pulp is mixed with 183 kg of potassium chloride and dried to remove 143.4 kg of water. As a result, N: P 0: K 0 1: 1: 1 with a total nutrient content of 33%.

The degree of retrogradation at the ammonization stage in this process is 3% instead of 10% by a known method. As a result, the consumption of apatite per 1 ton of fertilizer is reduced by 22.7 kg.

Example 2. 290.8 kg of apatite concentrate are treated with 262.3 kg of 56% nitric acid and 206 kg of 93% sulfuric acid for 40-60 minutes. The resulting pulp is neutralized with stirring 20.8 kg of ammonia gas, and then 156.8 kg of ammonium nitrate ammonia (i.e. 70% of the mass of ammonia gas) is added to pH 5. The neutralized pulp is mixed with 183 kg of potassium chloride and dried with removing 119.7 kg of water. The result is 1000 kg of complex fertilizer (nitrophosphate) with the ratio N: P205: K20 1: 1: 1 with a total nutrient content of 33%.

The degree of retrogradation P of the ammonization stage in this process is 2% instead of 10% by a known method. As a result, the consumption of apatite per 1 ton of fertilizer is reduced by 25.7 kg.

The results are tabulated. From the data presented in the table, it can be seen that the implementation of the process with an additional supply of ammonium nitrate to the ammonium nitrate neutralization stage in an amount of 30-100% of the mass of ammonia supplied to the neutralizing ammonia (Example 1-3) reduces the degree of retrogradation at the neutralization stage to 2- 3% instead of 10% in the control example (example 5.). At the same time, the economy of apatite per ton of fertilizer is 22.7-25.7 kg.

The supply of ammonium ammonium nitrate to the ammonization stage allows the process to be carried out under milder conditions without local pereselachivatsii and with less heating of the neutralized suspension and allows you to reduce the degree of regaradation of phosphorus compounds at the ammonization stage to 2-3% instead of 10% in a known process (i.e., 3-5 times 5 MeHbttie). This is facilitated by the supply to the ammonization stage of a smaller amount of ammonia (or its complete elimination) due to the use of a significant part (or total ammonia) per 0 to produce ammonium nitrate ammonium outside the main production cycle and a decrease in heat release at the ammonization stage due to the dissolution of ammonia in the ammonium solution,. ammonium nitrate and cooling the resulting ammonia outside the main production cycle.

 The dissolution of ammonia in a solution of ammonium nitrate is removed under intensive heat exchange conditions for the preparation of ammonium nitrate ammonium nitrate outside the main process, and not by ammonization of acidic pulp containing phosphorus compounds.

Partial (or complete) replacement of gaseous ammonia with ammonia ammonium nitrate allows simplifying the instrumentation of the production process of complex fertilizer due to the elimination of multistage ammonization with ammonia in 10-12 reactors 13 with a known process and replacing it with 1-2 step neutralization with ammonia ammonium nitrate in 1-2 reactions50

55

tori.

 Impractical due to higher phosphorus retrogradation due to reaction with gaseous ammonia.

Editor H, Rogulich

Compiled by R. Gerasimov

Tehred M. Khodanich Proofreader V. Sinitska

Order 3666/25 Circulation 419Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, MoCKBaj Ж-35, Raushsk nab. 4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (2)

1. METHOD FOR PRODUCING COMPLEX FERTILIZER, including decomposition of phosphate raw materials with nitric and sulfuric acids, neutralization of the obtained pulp with ammonia, mixing it with potassium salt and drying of the finished product, characterized in that, in order to reduce the consumption of phosphate raw materials by reducing phosphate compounds retrograde , neutralization is carried out in the presence of ammonia ammonium nitrate. . 2. The method according to claim 1, characterized in that ammonia ammonium nitrate is introduced in an amount of 30-100% by weight of the ammonia fed to neutralize. b © b © Q0 Od