UA75743C2 - A method for the complex reprocessing phosphogypsum into fertilizers - Google Patents

Abstract

The invention relates to chemical industry and can be used at chemical enterprises, where phosphogypsum is formed with accumulating dumps thereof. A method for the complex reprocessing phosphogypsum into fertilizers involves preparation of ammonium carbonate solution, conversion of phosphogypsum with ammonium carbonate solution in reaction of exchange decomposition of salts, division of the suspension on filter obtained due to conversion into ammonium sulfate solution which is evaporated for obtaining crystalline or granulated ammonium sulfate, and in carbonate remainder, mixing the remainder with fusion cake ammonium nitrate, granulation and drying the mixture.

Description

ammonium carbonate solution, which is taken in the norm, (MNa)»ZOgr-n 2Н2Ор-n, dividing the obtained in the above 10095 from the stoichiometric, according to the exchange reaction, the result of the conversion of the suspension on the filter to the soluble decomposition of salts: ammonium sulfate, which evaporate to obtain

SabOg2NgOtv-(MNa)»СОзр-n-СасСоОзтв-- crystalline or granular sulfate of amo-"(MH)" ZOgr-n and 2Не2Ор-n, the separation obtained in rhenium, and on the carbonate residue, which is mixed from the result of the conversion of the suspension on the filter for a solution of liquid ammonium nitrate; granulation and drying of ammonium sulfate, which is decarbonized, processing mixtures, according to the invention, the conversion of phosphogypsum is carried out with sulfuric acid to neutralize carbonate, lead to less than the remaining ammonium steichiate at the rate of ammonium carbonate, and evaporate for odemetric and floating ammonium nitrate mix the bark of crystalline or granular sulfate or the entire conversion suspension, or partially from ammonia, and on the carbonate residue - phosphocrei- filtered unwashed residue and obtain a do, which is washed on the filter with water from occlude- sulfate lime-ammonium nitrate. of the mother plant to reduce sulfate losses. Technical effect of the proposed method: ammonium; mixing phosphochalk with ammonia solution - simplifying the process and saving sulfuric acid nitrate; granulation and drying of the mixture into apaslots, because in comparison with the prototype BGS carbonate (drum granulator-dryer) from ammonium otrate at a rate less than the stoichiometric extraction of lime-ammonium nitrate; capture and is spent entirely in the conversion products of the disposal of the outgoing gases (2). Disadvantages (sulfate solution, residue on the filter) of this method are: it, as a result, separation is either completely excluded - the complexity of the process, because the use of suspension or washing is partially filtered - ammonium carbonate norms above 10095 from the stoichiometric precipitate, as well as the decarbonization of the ria is excluded, it complicates the processes of separation of the conversion suspension-sulfate solution and neutralization of its sulfur content and subsequent processing of the sulfate solution with ammonium acid; and phosphochalk due to the presence in the suspension of residual - - reduction of heat consumption for the evaporation of ammonium carbonate, which is thermally unstable - undiluted sulfate solution, because it is a volatile salt and decomposes into ammonia and carbon - there is no need to evaporate excess lactic acid. Therefore, it is necessary to purify the gas water that was previously introduced for washing the occluded phase, decarbonize and neutralize the sulfated mother liquor and dilute the solution; solution, with the consumption of deficient sulfuric acid, - reduction of the duration and complexity of the process of washing the residue from the occluded uterus; su, because there is no need for the formation of a large - overexpenditure of energy for the evaporation of various particles of calcium carbonate; because due to the need to wash the spill - expansion of the range of fertilizers, because a large amount of water is brought into the tank, which dilutes the solution of ammonium sulfate and complicates it, a new type of evaporation is released along with (or instead of) the release of ammonium sulfate ; fertilizers - the duration and laboriousness of the process, because - sulfate lime-ammonium nitrate, with the possibility of improving filtration and washing by varying the phospho- viscosity within wide limits, the ratios go to increase the drying time (MNAMO:zi : |(СасСОзи |: KMNA)2504); suspensions in the reactor for the formation of sufficiently large - improving the quality of sulfate lime- and well-filtered particles of phosphochalk (the time of ammonium nitrate, because, as is known, the sulfate of the suspension in the reactor sometimes reaches required for the reaction of 2MNAaMO with "(MH4g)250, resulting in hygroscopic - 15...20 minutes); ness decreases. - release of only two products - ammonium sulfate and lime-ammonium nitrate; 1. Eliminating the need to use low sulfur, some lime-ammonium nitrate, refined acid, because nitrate is hygroscopic and non- One of the important advantages of the proposed high nitrogen content. this method saves sulfuric acid.

The task of the invention is to create a method of complex processing of phosphogypsum into fertilizers in order to simplify calculations, in which it is stated that phosphogypsum is the 10095th dihydride. The conversion of phosphogypsum is carried out at the norm of calcium sulfate carbonate, which does not change the essence of ammonium proponorate, less than stoichiometric, and with the flow of ammoniated solutions. of nitrate mix either the entire conversion suspension of ammonium carbonate, or a partially filtered, unwashed consumption of it per 1 t of phosphogypsum according to the real residues, and obtain sulfate lime-ammonia cation exchange decomposition of salts: composition: nitrate, which leads to simplification process, МН» Со з оо - (96 " 1000/172.14) - 557.7 kg, reduction of energy for evaporation of solutions, polyp- de 96 and 172.14 - molecular weights of carbonate of the quality of lime-ammonium nitrate, reduction of ammonium and phosphogypsum, respectively. duration and laboriousness of the process, expansion. In the known method, an excess of the assortment of products is used. ammonium carbonate. For example, when it is consumed

The set task is solved by the fact that in 10595 of the stoichiometry, the excess will be: methods of complex processing of phosphogypsum in additional МН» СоОзихат - 0.052 557.7 - 27, UKG. ryva, which includes: preparing a carbonate solution to neutralize this excess salt into ammonium; the conversion of phosphogypsum with a carbonate solution is related to the equation of ammonium according to the reaction of the exchange decomposition of salts:

CaO g2HgOtv-(МНО»СОзр-н:СасСоОзтвч- is required for sulfuric acid monohydrate

ИНг5О4и - (98 »« 27.9/96) - 28.5 kg, rii, - 9996; where 98 and 96 are the molecular weights of sulfuric acid - the concentration of ammonium carbonate solution - and ammonium carbonate, respectively. 45965 (МНА) 2 СОз

In the proposed method, ammonium carbonate is used - the degree of use of ammonium carbonate - is in short supply, that is, at a rate less than stoichiometry - 10096; annual (less than 10095). Therefore, ammonium carbonate reacts - the coefficient of conversion of gypsum into calcium carbonate is completely absent in the reaction products. Tim -100 0.99 - 9995; by itself, the need for sulfuric acid is eliminated - the temperature of the conversion suspension is 507; those - up to ZO0 kg of sulfuric acid is saved at - the concentration of the liquid ammonium nitrate after processing tt of phosphogypsum. Remains of phosphogypsum in the VTN apparatus - 9295; to the finished product are insignificant and do not affect the quality - - the melting point of ammonium nitrate after the last one. VTN apparatus - 13020; 2. Release of sulfate lime-ammonium nitrate - the ratio (MNAMOZZi: |(CaCOzi - 60:40;

In this variant, the entire conversion suspension - the moisture content of the finished product - is 4965. without separating it on the filter, it is mixed with liquid ammonia 2.1 Conversion of phosphogypsum with carbonated nitrate solution after the VTN apparatus (ammonium heat neutralization user) from the production of ammonium salt - the material balance of the conversion stage is calculated three, the resulting mixture is granulated, dried and detached based on the stoichiometry of the exchangeable calcium-ammonium nitrate sulfate reaction. decomposition of salts in accordance with the given

Initial data: the initial data are given in Table 1. - the rate of ammonium carbonate, at 9° from the stoichiomet-

Table 1

Material balance of the phosphogypsum conversion stage (per 1000 g of phosphogypsum) 1. Phosphogypsum 1000 100 y y y no | 759 bob - (MNa) 2504 incl. But " (МНоОг2СОз - -

МН» СО with 675.3 Ko) 882.5 53.74

СазОг2НгО 10 1.71 2.2 Mixing of the conversion suspension with the float of ammonium nitrate Mass of 9295th float of ammonium nitrate, which is fed for mixing with the conversion suspension

IMNAMO z) - 575.6-60-100/(40-92) - 938.5 kg, including: MNAMOz - 863.4 kg, water - 75.1 kg. The mass and composition of the resulting pulp, which is fed to granulation, are given in Table 2.

Table 2

Mass and composition of the pulp fed to granulation

Pulp: - liquid phase, including:

MNAMO»z 863.4 33.46 (MNoO»ZOH 759.7 29.44 sho) 957.6 37.10 - sediment, including:

SasSoz 575.6 98.29

СазОг2НгО 10 1.71

The temperature of the beginning of crystallization of the liquid phase is 58"C. We compare it with the temperature of such a composition (see Table 2) according to |4| of the solid pulp, which is found from the heat balance of

mixing process. .130--22278.-2,3.50 can be submitted for granulation by dental

Ipul ttddov 35334335 5987С pumps (9388--22237.2,7 : ! 2.2 Pulp granulation and drying of the product , , y y y In the process of granulation of the mixture and sulfate serpentine sepitra, conversion suspension and pulp of 0 zapnyanogamiach nitrate, drying to residual kJy (kg K) ( ZI. 5576 vn A

Since cr « ilul, both nitrate and sulfate salts 96 . ammonium - do not precipitate and remain dissolved in the liquid phase of the pulp. Correspondingly, Table C shows the composition of the finished product (liquid phase) (precipitation) in the pulp is r:t-2580.7:585.6-4.4:1, that is, the mixture is mobile and

Table C

The composition of sulfate lime-ammonium nitrate

MNAMO»z 863.4 37.53 (MNa)25O4 759.7 33.02

SasSoz 575.6 25.02

SabzO-2NgO 10.0 0.43 sho) 92.0 4.00

Nitrogen content in the finished product - melting point of ammonium nitrate after 37.53-0.35 - 33.02: .0.2121 - 20.1496, VTN apparatus - 1302; where 0.35 and 0.2121 - the nitrogen content in salts (MNa)25O4 - the ratio (MNAMOZZi : |(CaCOzi - 60:40; and MNAMO with, respectively. - moisture content of sulfate lime-ammonium selt- 3. Output of two products - of ammonium sulfate and ry - 495; of sulfate lime-ammonium nitrate - the moisture content of crystalline ammonium sulfate -

In this variant, the conversion suspension is partially 290. separated on the filter. The filtered liquid ammonium sulfate is evaporated and further processed. turn into a solid product. Residue from the filter 3.1 Conversion of phosphogypsum carbonate solution is mixed with molten ammonium nitrate and ammonium is processed. its balance corresponds to table 1.

Output data: 3.2 Partial division of the conversion suspension - rate of ammonium carbonate, at 9° from the stoichiometry - on a filter, - 99965; According to the accepted initial data, in - the concentration of the ammonium carbonate solution - the residue on the filter is the occluded ammonium sulfate solution (575.6 10) -60/40 - 878.4 - the degree of use of ammonium carbonate 00905; kg, including: KМНl)25041-878.4-0.4626-406.25Kkg and (НгО) - coefficient of conversion of gypsum to calcium carbonate - - 878.4-0.5374-472.05kKg. 100 0.99 -99965; Ammonium sulfate solution is filtered - the temperature of the conversion suspension is 507C; 16422 - 878.4-763.8 kg, including: (МНО»5О4)| -763.8- - the share of the occluded solution of ammonium sulfate 0.4626 -353.35 kg and (HgO) - 878.4-0.5374 - 410 44 kg in the phosphogypsum residue on the filter is 60905; The material balance of the stage is summarized in tables - the concentration of ammonium nitrate melt after this 4. VTN apparatus - 92965;

Table 4

Partial division of the conversion suspension on the filter sen ee! | to live including: ammonium, including: (MNogoO»z - - no 410.44 53.74

Neo 882.5 53.74 2. The residue on the filter - dust - sediment, including: ri, tu. h.:

SasSoz 575.6 39.32 so. and with nn no 472.05 32.24

СазОг2НгО 10 1.71 СсавоГ?нНО 10 0.68 3.3 Evaporation of ammonium sulfate solution and (МНг»5О4| «353.35 kg, IN2гО| - 7.21 kg. drying of the crystalline product Evaporated water: 410.44 - 7.21 - 403.23 kg.

The mass of crystalline ammonium sulfate during its In table 5, the balance of the stage of evaporation and drying of solid ammonium sulfate is given. 353.35/0.98 - 360.5 bkg, including:

Table 5

Evaporation and drying of solid ammonium sulfate and 1. Solid sulfate 1 "Solution of ammonium sulfate, in ammonium, including: grinding (МН.Ад»8Ох 353.35 98 (МНоО»ЗОХ 353.35 46.26 but 7.21 2

But 410.44 53.74 3.4 Mixing the rest of the conversion suspension Mass of ready-made sulfate lime-ammonium se- with liquid ammonium nitrate, granulation of the mixture and liters at its humidity 490 drying of the product (863.4 4 575.6 - 10 i 406.35) "« 100/96 - 1932.66

The weight of 92905 floats of ammonium nitrate, which is per kg, including: salts - 1855.35 kg, water - 77.31 kg. given for mixing with the remaining conversion The mass of water removed during granulation and suspension is equal to drying, 575.6-60-1007(40-92) - 938.5 kg, including: 547.15-77.31- 469 84kg .

IMNAMOzi - 863.4 kg, (NhOYI 75.1 kg. The material balance of the stage of granulation and drying

The total water content in the pulp: 71.5 g 472.05 - 547.15 kg of sulfate lime-ammonium nitrate is given. in table 6.

Table 6

Material balance of the stage of granulation and drying of sulfate lime-ammonium nitrate

Pulp, including: 1 Ready, product, in

MNAMO" with 863.4 35.94. including:

SasSoz 575.6 23.96 MNAMO»z 863.4 44.67 (MNoO»ZOH 406.35 16.91 SasSoz 575.6 29.78

SabzO-2NgO 10 0.42 (MNO»ZOH 406.35 21.03 no 547.15 22.77 SazOg2NgO 10 0.52 sho) 77.31 4.00

Continuation of table b 2. Water vapor 469.84 469.84 24025 2402.5

Nitrogen content in the finished product Nitsky, P. V. Klassen, A. A. Novikov and others - M.: Khy- 44.67-0.35--21.0320.2121 - 20.10 95, where 0.35 and Mia, 1990. - 224 p. 0.2121 - nitrogen content in salts (MNa)2504 and MNAMO»z, 2. Mytronov A.P., Pukish M.D., Mudryi A.P., respectively. Complex processing of phosphogypsum // Sat. scientific

Thus, the proposed method of processing works. "Modern problems! chemical phosphogypsum allows to obtain a new pro- technologies of inorganic substances": Mezhdun. duct - sulfate lime-ammonium nitrate with various scientific - technical conf. - Odesa: Astroprint, 2001. - S. by the ratio of salts (MNAMOz)| : И|СаСОзи| : 99-101. ((МНгО250и, and if necessary also obtain Z. Technology of ammonium nitrate. Edited by crystalline ammonium sulfate. The choice of the variant of Pedok.Techn. Sciences, Prof. V. M. Olevsky. M.: Chemistry, rework depends on the desired nomenclature and 1978.-312 pp. composition of products. 4. Pozin M. E. Technology of mineral

Sources of information ley.- L.: Khimiya, 1974.- 1564 p. 1. Phosphogypsum and its use /V. V. Iva-

Computer layout M. Klyukin Signature Circulation 26 approx.

Ministry of Education and Science of Ukraine

State Department of Intellectual Property, str. Urytskogo, 45, Kyiv, MSP, 03680, Ukraine

SE "Ukrainian Institute of Industrial Property", str. Glazunova, 1, Kyiv - 42, 01601