Granulated conditioned fertilizer manufacture process
FIELD: mineral fertilizers.
SUBSTANCE: invention relates to granulated mineral fertilizers containing ammonium phosphates modified by surfactants and powdering substances, which do not lose their physicochemical properties during transportation and storage. Manufacture process comprises granulation of ammonium phosphate pulp, drying of granules, sorting and selection of commercial fraction, cooling and addition of modifying supplements. The latter are added in the cooling stage into zone with bed temperature by 5-10°C exceeding temperature of cooled product. Conditioning additives utilized can be either only liquid or the same mixed with dry powdering substances.
EFFECT: improved quality of surface coverage and simplified process.
2 cl, 3 ex
The invention relates to a method of manufacturing granulated mineral fertilizers containing ammonium phosphates, modified surfactant and opudrivayuschee substances, which do not lose their physico-chemical properties during transportation and storage, and therefore widely demanded by the consumer.
Known method of applying a conditioning additive granules in the apparatus with fluidized bed at a temperature of layer 75°when this temperature is drying or curing the coating substances. (PV is cool, I.G. Grishaev "Major processes of mineral fertilizers, M.: Chemistry, 1990, s-239).
The disadvantages of this method are the need for drying or polymerization modifier fluid and, as a consequence, the limited range of used additives. This process cannot simultaneously dusting granules (optional operation). It also requires additional energy consumption for the process of drying or polymerization.
Closest to the proposed is another known method for producing granulated fertilizers, such as ammonium sulphate, comprising granulating the slurry, drying the granules, the classification with the Department of commodity fraction, cooling it, the introduction of conditioning additives. The process is carried out as the way. The pulp obtained by neutralization of phosphoric acid with ammonia, served in a drum granulator-dryer (BGS) and atomized with compressed air on the veil reture. In the apparatus BGS enter the coolant. The product of the BGS serves on the classification and commodity faction - the cooling apparatus with fluidized bed. After cooling carried out surface modification (air conditioning). The conditioning process is done in rotating drums with a diameter of 1.5-1.8m, length 4-6 m (power of the motor 11-15 kW), at the head of which (along fertilizers) sprinkle aisleways additive, and in the middle part of the screw serves outrivals Supplement. ("Technology of phosphate and compound fertilizers". Edited by S.D. of Eventica and A. Brodsky, M.: Chemistry, 1987, C-192, 261).
The disadvantages of this method include a multi-stage process (cooling, coating liquid, washing powder) and the bulkiness of the equipment used. In addition, due to the fact that the conditioning additive is applied on cold granules, liquid unevenly distributed over their surface, which affects the quality of the finished product, but also requires a larger flow rate applied to the granules additives.
We were set a task to create a method of obtaining air-conditioned granular fertilizers containing ammonium phosphates, are deprived of the significant shortcomings of the prototype method, allowing to obtain granules with high-quality surface coating while reducing its consumption and to simplify the process by eliminating the bulky part of the technological equipment.
The problem is solved in the proposed method comprising granulating the slurry, drying the granules, the classification with the Department of commodity fraction, cooling it, the introduction of conditioning additives. According to this method, the conditioning additive is injected through the cooling zone temperature exceeding 5-10°With the temperature of the cooled product. As conditioning additives are used or only liquid additives, or their mixture with dry opudrivayuschee substances.
In our proposed method may simultaneously perform the processes of cooling, makiwane and dusting granules, or, depending on the requirements of the consumer, only makiwane and cooling. As liquid additives can be used industrial oils, primary amines, dispersant NF, oil, sulfinol, calcium stearate and others, and dry - diatomite, kieselguhr, dolomite powder, phosphorite flour and other stage cooling granules of mineral fertilizers containing phosphates of ammonium, combined with their conditioning. A very important temperature zone of feed additives in the product. We found that the rate the temperature of the layer of granules to exceed the temperature of the cooled product by 5-10° C. If the difference in temperatures below 5°With the adhesion of deposited substances on the small granules. If the difference in temperature more than 10°With, modifying additives, filling in pores. Both leads to a deterioration in the quality of the coating and increase the amount of injected additives. Reducing the number of input conditioning additives is especially important due to the fact that currently do not have the necessary resource liquid modifiers.
The use of the proposed method will greatly simplify the technological scheme of the process (due to combination of stages of cooling and air conditioning), improving the quality of air fertilizers, reduce the number of conditioning additives and thereby improve the efficiency of their use.
The method is illustrated by the following examples.
Example 1. The slurry of ammonium phosphates in the amount 48000 kg/h, obtained by neutralization of phosphoric acid with ammonia, atomized in a drum granulator-dryer (BGS), which simultaneously serves hot coolant with a temperature of 350°C. the resulting drying pulp pellets discharged from BGS, weed out the screens 40000 kg/h marketable fractions 2-5 mm, which is served in a rotary dryer-fridge (HB), blown cold air taken into the number 65000 kg/h at a temperature of 18°the. At the same time in HB at a distance of 3 m from the discharge zone temperature layer 55°From (i.e. higher than the temperature of the cooled product by 10° (C) pneumatic nozzle atomized 100 kg/h industrial oils. From HB unload 40100 kg/h modified map at a temperature of 45°C. Caking of the product 35 kPa.
Example 2. The pulp diammofosa in the amount of 24000 kg/h, obtained by neutralization of phosphoric acid with ammonia, atomized on a layer of granules in a rotating drum ammoniator-granulator. This also serves potassium chloride in the amount of 10000 kg/h Temperature granulation 75°C. the Resulting pellets Dimovski come in a rotary clothes dryer, where drying through hot air, supplied with temperature 240°C. the Dried granules disperse on the screens, where separate 40000 kg/h marketable fractions 2-5 mm, which is served in a rectangular refrigeration apparatus with fluidized bed (PS), blown cold air in the number 65000 kg/h at a temperature of 18°C. Simultaneously in the refrigerator at a distance of 1.5 m from the discharge in an area with a temperature of layer 52°C, i.e. above the temperature of the refrigerated product on 7°With pneumatic dual nozzle atomized 120 kg/h industrial oils and 400 kg/h powder diatomite. Of the apparatus with fluidized bed in Gruaud 40520 kg/h modified Dimovski at a temperature of 45° C. Caking of the product 30 kPa.
Example 3. The solution of ammonium nitrate in the amount of 18000 kg/h mixed with ammonium phosphate, taken in the amount of 450 kg/h, the resulting slurry is atomized in BGS, where you can enjoy a hot fluid with a temperature of 180°C. the resulting drying pulp pellets nitrogen-phosphate fertilizer total nitrogen content of 27% and P2O55% unloaded from BGS and on screens eliminate 15000 kg/h marketable fractions 2-5 mm, which is served in a rectangular refrigeration apparatus with fluidized bed, blown cold air in the amount of 25000 kg/h at a temperature of 18°C. Simultaneously in the refrigerator at a distance of 1 m from the discharge zone with a temperature of layer 50°C, i.e. above the temperature of the refrigerated product 5°With pneumatic nozzle atomized 20 kg/h of AA oxidationin (ODA). Of the apparatus with fluidized bed unload 15020 kg/h modified nitrogen-phosphorus fertilizer at a temperature of 45°C. Caking of the product 40 kPa.
1. The method of obtaining the air-conditioned granular fertilizers containing ammonium phosphates, including granulating the slurry of ammonium phosphates, drying the granules, the classification with the Department of commodity fraction, cooling it, the introduction of conditioning additives, characterized in that the conditioning additive centuries is completed at the stage of cooling in the zone with the temperature of the layer, exceeding 5-10°With the temperature of the cooled product.
2. The method according to claim 1, characterized in that as conditioning additives are used or only liquid additives, or their mixture with dry opudrivayuschee substances.
FIELD: chemical industry, agriculture, in particular hardness removal agent and saltlick for cattle.
SUBSTANCE: salt with pH 4-10 is pressed under 5000-2500 N/cm2. Salt contains NaCl, less than 0.1 wt.% of water, and iron-ammonium complex of polyhydroxycarboxylic acid in amount sufficient to obtain non-caking salt. As iron-ammonium complex of polyhydroxycarboxylic acid iron-ammonium citrate with molar ratio of iron to citrate-ion from 0.5 to 2 and molar ratio of ammonium to citrate-ion from 0.5 to 2 may be used. Finished product contains 0.1-20 mg/kg of iron and has form of briquettes, balls, bars, crushed plates, tablets, etc. Invention makes it possible to provide good formability under high pressure and conserve pressed product shape in moist medium for a long time.
EFFECT: products from salt non-caking at storage and conveyance.
11 cl, 6 tbl, 2 dwg, 7 ex