SU1583402A1 - Method of producing ammophosphate - Google Patents

Abstract

The invention relates to the production of nitrogen-phosphate fertilizers, contributes to improving the quality of the product and improving the processability of the process by preventing pelletizing of the granulate and sticking it onto the walls of the drying apparatus. According to the invention, the phosphate raw material is decomposed with phosphoric acid, neutralized with ammonia gas, the phosphate pulp formed during decomposition is granulated and dried. Before granulation, the phosphate pulp is evaporated and / or returnee into it until the moisture values satisfy the condition W≤10 (PH + 4.5N-3.16) °, 3, where W is the material moisture content, wt.%

PH is the hydrogen index of the neutralized pulp

N is the mass ratio of P 2O 5 in the initial reagents. The method improves the quality of the product, the content of P 2 O 5 by the known method is 39.0%, and according to the proposed 44.9%, the processability and efficiency of the process are ensured, the technological equipment is used to the maximum and its unproductive stops are eliminated.

Description

The invention relates to the production of nitrogenous phosphate fertilizers from natural phosphate raw materials and can be used in enterprises producing mineral fertilizers.

The purpose of the invention is to improve the processability of the process by preventing pelletizing of the granulate and sticking it onto the walls of the drying apparatus.

Example 1.10kg of phosphate containing, in May.%: 25.03; CaO 39.42; MgO 2.60; , 23; - CO 4.70; F 2.08; and about. 18.13, decompose 100 kg

extraction phosphoric acid containing, in wt.%: Pr05.22.70; CaO 0.5; , 39; 80E 2.45; MgO 1.65, at 50 ° C for 3 hours. 109 kg of phosphate pulp is obtained, which is neutralized with gaseous ammonia to a pI value of 3.0; evaporated to a moisture content of 30% and, in an amount of 80 kg, is sent to granulation, where it is mixed with 220 kg of a handler. The moisture content of the granulate is: 100 (80-0.3 + 220-0.01) / (80 4- 220) 8.7% with the required value of W, Ј10, 0 + 4.5-10-25.03 / 000-22, 7) - - 3, l63fti 0.72. The material sticks to the walls of the dryer and crumples.

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Example 2. The phosphate pulp obtained in Example 1 is neutralized with ammonia until the pI value of 3.5 is evaporated to a moisture content of 30%, mixed with 220 kg of retur, granulated and dried. The moisture content of the granulate is 8.7% with the required value of WЈ 10 3.5 + + 4, 5-10: 25.037 (100-22.7) - 3.16 ° -3.9.5. After drying, 276 kg are obtained. About material with a moisture content of 1%, from which 56 kg of fertilizer is extracted in the form of conforming granules, containing, masv%: Pr0505; 4t, Ot P205 8vd "22.9, - N 4.4. 220 kg of dry material returned to granulation

Example 3. One stripped off the ammophosphate pulp obtained in Example 1, mixed with 300 kg of retur, granulated and dried. The moisture content of the granulate is -, lt 100 (80-0; 3 + 300-0,01 (7 (80 +. M + 300) 7.1% with the required value

W Ј7f2. After drying, 355 kg of material with a moisture content of 1% is obtained, from which 55 kg of fertilizer is extracted in the form of conditioning granules, containing, in wt.%: P405, 43.1; P205use41,8; RL0 $ Vvyi 26E4; N 4P3 - 300 kg of dry material is returned to the granulation,

Example 4. 20 kg of phosphorite containing, by weight,%: Р20 27.41; CaO 44,14; MgO 2.21; R, 03 1.35; F 2.48;

 C02 3S80, n, o, 14.84, decompose 100 kg of apatite extraction phosphoric acid containing, in wt.%: 26–16; CaO 0.32; Rt03 1.40; SQ3 1.18, 35 at 50 ° C for 3 h. 118 kg of phosphate pulp is obtained, which is neutralized with gaseous ammonia.

| until pH 3E7 is evaporated to a moisture content of 35% and in the amount of 97 kg 40

served on granulation, where it is mixed with 200 kg of retur. "The moisture content of the granulate is 100 (970.35 + 200 0:01) 7 7 (97 + 200) 12.1% with the required value W, 7 + 4,520-27,417 4i 7 (100.26,16) 3, - 11.2%. The material is crumpled and adheres to the walls of the apparatus,

Example 5 Ammophosphate pulp obtained in Example 4 is packed to a moisture content of 30% and, in an amount of 90 kg, mixed with 200 kg of retur, granulated and dried. The moisture content of the granulate is 100 (90-0.3 + 200 0.01) / (90 200) 10% with the required 55 value of W Ј11.2%.

267 kg of material with a moisture content of 1% is obtained, from which 67 kg is extracted.

fertilizer in the form of conditioned granules, containing, in wt.%: Od-h 44, 9; , 0; P205vod 7.8; N 6.2. 220 kg of dry material is returned to the granulation.

Thus, the proposed method allows one to purposefully control the moisture content of the material entering the drying process depending on the parameters of the neutralized pulp, while the moisture content of the material entering the granulation and drying is maintained at the level determined by the formula

W 10 (pH + 4.5p - 3.16) ° 3,

where W is the moisture content of the material, wt.%; pH is the hydrogen index of the neutralized pulp; n is the mass ratio in the pulp P Qf iPyOsK; P is the mass entering

pulp from phosphate raw materials; - the mass arriving at

Claims (1)

phosphoric acid pulp. From the presented examples it is clear that the proposed method contributes to improving the quality of the product (the content of d $ y by the known method is 950% j no proposed 4.9%), and also provides high manufacturability and process efficiency, allows maximum utilization of the process equipment and eliminates its unproductive stop .. Formula of the invention The method of producing ammophosphate, which includes decomposition of phosphate raw materials with phosphoric acid, neutralization of the phosphate pulp formed by decomposition of phosphate pulp with ammonia gas, granulation and drying of the product, characterized in that, in order to increase the content of the product and improve the processability by preventing the granulation and sticking it onto the walls of the drying apparatus, prior to granulation, the phosphate pulp is evaporated and / or introduced into it until the moisture values W (relative to%) are reached meeting the condition: W.iHO (pH + 4.5p - 3, 16), where pH is the hydrogen pocer of the neutralized pupli; n - mass matching in the original pearpii r ..