Method of manufacturing granulated mineral fertilizer containing nitrogen and phosphorus; and granulated mineral fertilizer
FIELD: mineral fertilizers.
SUBSTANCE: method of manufacturing complex granulated mineral fertilizer consists in mixing ammonium nitrate and monoammonium phosphate-containing phosphate additive. The latter is granulated mineral double fertilizer simultaneously containing ammonium nitrate, monoammonium phosphate, and calcium phosphates at total content of digestible phosphorus 13÷21% (calculated as P2O5). Additive is introduced by way of melting it followed by admixing resulting melt to molten ammonium nitrate. Phosphate additive utilizes nitroammophosphate at weight ratio N:P2O5 equal to 23:21 or 26:13 and phosphate additive melt is preliminarily completely or partly separated from infusible solid phase, after which phosphate additive is introduced in amount 2-6% (as P2O5) of the weight of final product. Granulated mineral fertilizer contains ammonium nitrate and monoammonium phosphate with total content of digestible P2O5 within a range of 2÷6%, in which case 0.4÷28.6% of P2O5 is present in the form of dicalcium phosphate.
EFFECT: reduced corrosiveness of process medium, increased nutritive value of fertilizer having physicochemical properties competitive with those of known fertilizers, and simplified manufacturing technology.
5 cl, 1 tbl, 5 ex
The invention relates to the chemical industry and can be used in the production of granulated mineral nitrogen-phosphate fertilizers containing nitrogen in the form of ammonium nitrate and phosphorus in the form of monoammonium phosphate and dicalcium phosphate.
A method of obtaining mineral nitrogen-phosphate fertilizers by neutralizing ammonia nitric acid with the addition of thermal phosphoric and sulfuric acids, parki neutralized solution and melt granulation [Production of ammonium nitrate in units of large capacity Ed. Vmelilo, vol. 2, M.: Chemistry, 1990, s-164]. The disadvantage of this method is the low content of phosphorus in the fertilizer (0.5% R2O5), which devalues its consumer properties.
The closest to the essential features and the result achieved by the present invention is a method of obtaining a granulated mineral fertilizers containing nitrogen and phosphorus, including the neutralization of nitric acid with ammonia, and the introduction of a solution of monoammonium phosphate as phosphate additives, oparka neutralized solution and the granulation of the melt. Phosphate additive is introduced from the calculation of the content of P2O5up to 7% in the target product [U.S. Pat. Of the Russian Federation No. 2169720, IPC 7 05 7/00, 05 G 1/06, publ. 27.06.2001].
Lack of know what about the method is the high corrosiveness of the technological environment. The solution of the map (the main component of the solution - phosphate), as all phosphate fertilizers produced by acid processing of natural calcium phosphates, contains impurities of fluoride (up to 0.8% in relation to R2About5when the residue is partially transferred into the gas phase, leading to its high corrosivity. In industrial terms, this manifests itself in corrosion damage of the walls of the flues of the juice of steam and the need to address the emerging "leaks".
The technical task of the present invention is to reduce corrosiveness of the technological environment.
The problem is solved in that in the method of obtaining complex granulated mineral fertilizers based on ammonium nitrate and phosphate supplements containing monoammonium phosphate, comprising a mixture of phosphate supplementation with ammonium nitrate, the granulation of the melt, according to the invention as phosphate additives used granulated mineral dual fertilizer containing both ammonium nitrate, monoammonium phosphate and calcium phosphate in a total content of available phosphorus 13-21% in terms of P2About5and the introduction of a phosphate additive is carried out by melting and mixing the obtained melt in the melt of ammonium nitrate.
As phosphate additives COI is lsout nitroammofosfat with the mass ratio of nutrients N:P 2About5equal 23:21 26:13.
Melt phosphate additives previously fully or partially separated from infusible solid phase.
Phosphate additive is introduced in the amount of 2-6% in terms of P2About5by weight of the finished product.
Together with phosphate addition on the proposed method introduces a certain amount of ammonium sulfate, which is present as impurity in nitroammofosfata used as phosphate additives. However, the presence of sulfate as an impurity may in many types of fertilizers, therefore, the presence of ammonium sulfate in the target product obtained by the present method, is not an essential attribute.
In granular fertilizers containing ammonium nitrate and monoammonium phosphate with a total content of digestible P2About5within 2-6%, and 0.4-28.6 Rel.% P2About5present in the form of dicalcium phosphate.
To obtain nitrogen-phosphate fertilizers take 1000 g of a melt of ammonium nitrate with a moisture content of 0.1 wt.% and 190 g of granulated mineral dual fertilizer - nitroammofosfata 23:21, contains, wt%:
ammonium nitrate 57,0
monoammonium phosphate 24,3
the dicalcium phosphate 11,5
ammonium sulfate 1,5
ballast impurities (connections
iron, aluminium, titanium dioxide
including fluoro - 1,3
N is roommatesthat melted at 140° With, mixed with a melt of ammonium nitrate and the resulting mixture granularit laboratory granulator. While getting 1190 g of the target product, contains, wt%:
|monoammonium phosphate (map)||3,88|
|the dicalcium phosphate||1,84|
The mass ratio of nutrients in the target product: nitrogen 33,1; patikis phosphorus 3,35, including in the form of monoammonium phosphate 2,39 (71.5 Rel.%).
Unlike example 1, 1000 g of a melt of ammonium nitrate take 250 g of nitroammofosfata (composition as in example 1), which is melted and the resulting melt before mixing with the melt of ammonium nitrate pre-filtered through a metal grid with a cell size of 0.2 (0,2 mm. receive 61,0 g wet sediment, which in industrial conditions utilized in the production of nitroammofosfata, and 189 g of the filtrate of the following composition:
|monoammonium phosphate (map)||27,22|
|the dicalcium phosphate||3,81|
Specified the filtrate is mixed with a melt of ammonium nitrate, a mixture granularit and get 1189 g of the target product. His composition, wt.%:
|monoammonium phosphate (map)||4,32|
|the dicalcium phosphate||0,60|
The mass ratio of nutrients: nitrogen 33,5; patikis phosphorus 3,0, including in the form of monoammonium phosphate to 2.67 (88,9 Rel.%).
To 1000 g of a melt of ammonium nitrate added, respectively, 106, 236 and 400 g of melt nitroammofosfata, the mixture granularit and get the target product number 1106 g (experiment I), 1236 g (experiment II) and 1400 g (experiment III) of the following composition, wt.%:
|monoammonium phosphate (map)||2,33||with 4.64||6,94|
|the dicalcium phosphate||2,20||3,29|
|The mass ratio of nutrients:|
|including R2About5in the form of monoammonium phosphate||the 1.44||2,86||4,28|
|(71,9 Rel.%)||(71,51 Rel.%)||(71.4 Rel.%)|
To obtain the target product using 1000 g of water containing, wt.%: 99.1 ammonium nitrate, 0.8 ammonium sulfate and 0.1 water, and 300 g of nitroammofosfata N:P2O523:21. Nitroammofosfat melted, filtered through the grid of 0.1·0.1 mm, thus obtain 98 g of wet sediment, recoverable in an industrial environment in the production of nitroammofosfata, and 202 g of the filtrate of the following composition, wt.%:
|monoammonium phosphate (map)||28,76|
|the dicalcium phosphate|
The mass ratio of nutrients: nitrogen 27,5; patikis phosphorus 18,2.
The filtrate is mixed with water, the mixture granularit and receive 1202 g of the target product, contains, wt%:
|monoammonium phosphate (map)||4,84|
|the dicalcium phosphate||0,12|
The mass ratio of nutrients: nitrogen 33,6; patikis phosphorus 3,0, including in the form of monoammonium phosphate 2,99 (more than 99,6 Rel.%).
As phosphate additives use granular fertilizer - nitroammofosfat brand 26:13 the following composition, wt.%:
|monoammonium phosphate (map)||16,2|
|the dicalcium phosphate||to 7.67|
To stay afloat ammonium nitrate in the amount of 1000 g with a water content of 0.1 wt.% add 214 g nitroammofosfata 26:13, the resulting mixture granularit and get 1214 g of the target product of the following composition, wt.%:
|monoammonium phosphate (map)||2,86|
|the dicalcium phosphate||of 1.34|
The mass ratio of nutrients: nitrogen 33,6; patikis phosphorus 2,47, including in the form of monoammonium phosphate 1,77 (71.5 Rel.%).
For clarity, data on the composition of the fertilizers produced in examples 1-5 are summarized in the table. In column 9 of the table shows the share of R2O5in the fertilizer in the form of dicalcium phosphate.
When conducting experiments, a sample was taken of the gas phase above the melt of ammonium nitrate with phosphate additive and analyzed it on the content of fluorine compounds. In all experiments fluoride are missing. The absence of fluorine in the gas phase means that it has no corrosive properties.
There was also a special experience, which was draped samples isstale 12X18H10T and titanium in the gas phase above the melt of ammonium nitrate with phosphate additive in the form of nitroammofosfata 23:21. Examination of samples after exposure for 24 h showed that corrosion is absent.
The reduction in corrosion activity due to the fact that the phosphate additive is introduced into the melt in the melt of ammonium nitrate, i.e. there is no oparka mixture containing phosphate additive, and hence there are no conditions conducive to the emission of compounds of fluorine in the gas phase. In the known method the phosphate additive is introduced in the form of a solution in 85-90%ammonium nitrate solution, followed by neutralization and parcoy neutralized mixture, which creates conditions for the allocation of fluorine compounds in the gas phase.
For samples of fertilizers obtained in examples 1-5 were determined some physical and mechanical properties. The strength of the pellet crush strength is not less than 2.5 kg granule, no caking. The resulting fertilizer on these indicators are much better than the known fertilizers based on ammonium nitrate.
The data show that the proposed method can eliminate the corrosivity of the technological environment and get a fertilizer with a high nutritional value, which according to the physical-mechanical properties (caking, the strength of granules) is not inferior to the famous fertilizers, and the technology of its receipt of uncomplicated entry and removal of water when in the yeseniya phosphate additives but as a Supplement to use accessible and affordable product - dual nitrogen-phosphate fertilizer with the content of P2About513-21%. Dual fertilizers with different content R2About5will determine the technological complexity with the introduction of phosphate additives in the melt of ammonium nitrate and is therefore impractical.
1. The method of obtaining complex granulated mineral fertilizers based on ammonium nitrate and phosphate supplements containing monoammonium phosphate, comprising a mixture of phosphate supplementation with ammonium nitrate, the granulation of the melt, characterized in that the phosphate additive use granular mineral dual fertilizer containing both ammonium nitrate, monoammonium phosphate and calcium phosphate in a total content of available phosphorus 13÷21% in terms of P2O5and the introduction of a phosphate additive is carried out by melting and mixing the obtained melt in the melt of ammonium nitrate.
2. The method according to claim 1, characterized in that the phosphate additive use nitroammofosfat with the mass ratio of nutrients N:P2O5equal 23:21 26:13.
3. The method according to claim 1, characterized in that the melt phosphate additives previously fully or partially separated from infusible solid phase.
4. The method according to claim 1, otlichuy is the, that the phosphate additive is introduced into the number 2÷6% in terms of P2O5by weight of the finished product.
5. Granular fertilizer containing ammonium nitrate and monoammonium phosphate with a total content of digestible P2O5within 2÷6%, characterized in that 0.4÷28,6 Rel.% P2O5present in the form of dicalcium phosphate.