Background technology
The production method of existing compound manure mainly adopts slurry process, granulating method, high tower spraying process etc.Slurry process makes with high-concentration phosphoric acid and ammonia react mostly, be characterized in technology, equipment complexity, the production technology difficulty is big, and to drop into huge fund, plant condition harshness, construction period are long, also have part producing factory to spray on the solid objects with the urea fusing, because urea melts the fusing point height separately, if add water-solubleization, then easily cause fertilizer moisture content height, need drying.Melting method is to utilize urea (or ammonium nitrate) solution of urea (or ammonium nitrate) factory dual circulation (concentration is 〉=95%) and phosphorus ammonium and sylvite melting mixing, utilize the high tower spraying process to produce nitrogen-phosphorus-potassium compound fertilizer, fertiliser granulates rounding, intensity height that this method is produced, but exist the regulation range of product particle size narrow, material proportion has certain limitation, only be adapted to the production of the low-phosphorous proportioning of high nitrogen, and prilling tower must have certain height, investment cost is also big.Though granulating method is fairly simple, because granulation moisture content height, drying load is big, and easily sticking flight causes the tails dedusting difficulty.
Summary of the invention
The objective of the invention is the advantage of granulating method and high tower spraying process is put together, and the two shortcoming is overcome, form a kind of method of brand-new preparing composite fertilizer by smelting solid material, make the versatility of fertilizer ratio stronger, the outward appearance of product be improved significantly, and product prevented from caking.
Purpose of the present invention can be achieved through the following technical solutions: the method for preparing composite fertilizer by smelting solid material, it is characterized in that, this method comprises following technology: the base-material that will be crushed to below 2.0 millimeters mixes with stopping composition, and will join behind this base-material and the stopping composition pre-heating temperature elevation in fused urea or the ammonium nitrate solution, stirred 3~8 minutes, generate molten slurry, keeping slurry temperature is 100~130 ℃, be injected to by pump then and contain returning charge or portion phosphate, on the solid materials of sylvite, make its coating granulating, material behind the granulating promptly gets the compound manure finished product through screening, and fine powder or macrobead return again.
Described base-material comprises one or more in ammonium chloride, sulphur ammonium, phosphorus ammonium, Repone K or the vitriolate of tartar.
Described stopping composition comprises rhombspar, lime carbonate, clay.
Described base-material and stopping composition pre-heating temperature elevation to 70 ℃~100 ℃.
The concentration of described urea or ammonium nitrate solution is 90~99.7 weight %, and this urea or ammonium nitrate solution are that temperature is 110~140 ℃ a urea soln in urea or the ammonium nitrate production process, or urea or ammonium nitrate are heated to 110~150 ℃ slip.
Described coating granulating technology is carried out in rotary drum granulator.
Principle of work of the present invention is: urea or ammonium nitrate and potash fertilizer can form the eutectic compound; with the two fusion of putting together; melting temperature is low, and melting charge slurry is injected in the rotary drum granulator by pump, forms the product of the mellow and full light of outward appearance by coating in layer.
In the existing granulating method compound manure production process, all need to replenish steam or water, can't improve prilling temperature like this, thereby material needs drying, and drying needs high temperature, under the well wet condition of high temperature, material easily sticks on the inwall and scraper plate of moisture eliminator, makes material can not get drying.
Method of the present invention does not need make up water when the rotary drum coating granulation, thereby drying-free, need not to remove accordingly dust recovery system yet.
The present invention compared with prior art has following advantage:
1, the present invention adopts the granulation of rotary drum coating method, is not adding water or steam in the granulation process, prilling temperature height, balling ratio height.Got rid of very high drying of investment and process cost and dust-removal system, do not had a large amount of exhaust emissionss when producing simultaneously, good operational environment, the production technique of genus clean and environment-friendly.
2, equipment of the present invention have simple in structure, be easy to installation and maintenance, than advantages such as high tower prilling investment are low.
3, the product of the present invention's production has the outward appearance and the intensity of high tower prilling particle, prevented from caking.But got rid of easy blocking sprayer of high tower prilling and prescription and be difficult for the little shortcoming of adjusting process turndown ratio.
4, the present invention organically combines high tower sprinkling pelleting and traditional rotary drum compound fertilizer production technology, realizes fusion drum granulating production compound manure.
Embodiment
The invention will be further described below in conjunction with specific embodiment, but be not limitation of the present invention.
Embodiment 1
Get urea plant flash evaporator outlet urea melting or melt 380kg; concentration is greater than 99%; temperature is 135 ℃; join tempering tank that has steam coils and the monoammonium phosphate 225kg that is heated to 115 ℃ in advance; vitriolate of tartar 200kg and stopping composition rhombspar 220kg mix, and send into granulation in the rotary drum granulator then, and the material after the granulation is the high-concentration granular NpK complex fertilizer through the cooling screening; this product contains N 20 weight %, P
2O
515 weight %, K
2O10 weight %, moisture 0.5 weight %, the granule strength of product is greater than 25 newton/grains.
Embodiment 2
Get solid urea 600kg and add the melting channel fusing; 135 ℃ of temperature of fusion; add the monoammonium phosphate 200kg that is heated to 100 ℃ in advance then; Repone K 150kg and stopping composition stone flour 50kg mix; slip behind the mixing is injected to granulation in the rotary drum granulator with pump; material after the granulation promptly gets the high-concentration granular NpK complex fertilizer through the cooling screening, and this product contains N30 weight %, P
2O
5Weigh 10 amount %, K
2O 9 weight %, moisture 0.5 weight %, the granule strength of product is greater than 25 newton/grains.
Embodiment 3
Get the evaporator outlet ammonium nitrate melt 400kg of ammonium nitrate factory, concentration is greater than 95%, temperature is 120 ℃, add tempering tank and the monoammonium phosphate 300kg that is heated to 110 ℃ in advance, Repone K 250kg and stopping composition clay 50kg mix, and spray into pump in the returning charge of corresponding proportioning, and coating granulation is after the cooling screening promptly gets the high-concentration granular NpK complex fertilizer, this product contains N 15 weight %, P
2O
515 weight %, K
2O 15 weight %, moisture 1.5 weight %, the granule strength of product is greater than 30 newton/grains.
Embodiment 4
Get solid ammonium nitrate 300kg with 100kg Repone K heat fused; 105 ℃ of temperature of fusion are injected to this solution the diammonium phosphate 210kg that is heated to 80 ℃ in the rotary drum granulator and in advance, Repone K 100kg and wilkinite 300kg mixing granulation then; promptly get and contain N12 weight %, P
2O
510 weight %, K
2O 10 weight %, the middle concentration complex fertilizer product of moisture 2.5 weight %
Embodiment 5
Get solid urea 200kg with 100kg Repone K heat fused; 100 ℃ of temperature of fusion are injected to this solution the normal superphosphate 500kg that is heated to 70 ℃ in the rotary drum granulator and in advance, vitriolate of tartar 60kg, terra alba 140kg mixing granulation then; promptly get and contain N9 weight %, P
2O
57 weight %, K
2O 9 weight %, the lower concentration complex fertilizer product of moisture 2.5 weight %.