Preparing method for industrial ammonium phosphate and series compound fertilizer
The invention belongs to phosphorus ammonium production technical field, is a kind of in the system with Wet-process Phosphoric Acid Production fertilizer grade ammonium phosphate, the method for coproduction industrial grade acid-ammonium and series compound fertilizer.
At present, adopt conventional " slurry process " technology, with phosphoric acid by wet process and the resulting ammonium phosphate of ammonia neutralization reaction, because it contains a large amount of impurity, can only be used as fertilizer usually, thereby make a low multiple use, economic benefit is also poor.In order to change this situation, the method (seeing CN 92108090.5) that prior art discloses a kind of " with phosphoric acid by wet process coproduction fertilizer grade and pure phosphoric acid-ammonium ".During this method is produced with " slurry process " and slip be raw material, adopt means such as separation, clear liquid concentrate, crystallisation by cooling to extract pure phosphoric acid-ammoniums, isolated slip and mother liquor return the raw material usefulness that original system is made the fertilizer grade ammonium phosphate after mixing in the process, and realize its goal of the invention with this.But, because the purification of raw materials that this method adopts is not enough, there is not additional control techniques again, so that the quality of product pure phosphoric acid-ammonium, promptly purity can not get guaranteeing completely; Secondly, make the raw material of fire-fighting with ABC powder extinguishing agent if use it for, its rate of moisture absorption index also is difficult for reaching requirement (promptly 20 ± 1 ℃, 78%, 24 hour rate of moisture absorption≤2% of relative humidity); Moreover, return separated the mother liquor behind the ammonium phosphate to original system, produce influence of fluctuations to system, suitably the adjusting process controlled variable could be eliminated, and this has brought operational trouble again.
Therefore, task of the present invention is to adopt " slurry process " to produce on the basis of fertilizer grade phosphorus ammonium system, do not changing its original Production Flow Chart, do not influencing under the prerequisite of its fertilizer grade phosphorus ammonium production, a kind of method for preparing industrial ammonium phosphate (being pure phosphoric acid-ammonium) and series compound fertilizer thereof is being provided.
Task of the present invention is finished by following technical proposals:
1. the enriching slurry of producing with " slurry process " is made raw material, starching: water=1: 0.3~1.5(weight ratio), 60~110 ℃ of temperature, agitation condition leached 10~40 minutes down, separate then, obtain the scavenging solution of phosphoric acid-ammonium and ammonium sulfate and contain the mud that does not dissolve body refuse.Contain the mud that does not dissolve body refuse and send the concentration section that returns fertilizer grade phosphorus ammonium production system.
2. the scavenging solution with phosphoric acid-ammonium and sulphur ammonium is concentrated into proportion 1.15~1.45(80 ℃ with conventional evaporating and concentrating process) after, crystallisation by cooling again.Technical grade phosphorus ammonium is washed and be drying to obtain to Crystallization Separation;
3. the mother liquor behind the fractional crystallization is with NH
3The proportioning of/K=0.8~4.0 (mol ratio) adds concentration and is 5~40% potassium chloride solution, and carries out conversion reaction 1~10 hour under 60~110 ℃ of temperature, and crystallisation by cooling separates then.The solid phase that obtains after the separation is that one-level does not have chlorine nitrogen phosphorus potassium and sprays multiple fertilizer, and remaining mother liquor is answered fertilizer owing to contain multiple nutrient based on ammonium chloride so can make liquid.
Become solid fertilizer in order to make to contain based on the multiple fertilizer of the liquid of ammonium chloride, so that transportation and fertilising operation, the present invention is off the beaten track, on technique scheme, increased a kind of special technology again, that is: with the remaining mother liquor in conversion reaction separation back, press mother liquor: the proportioning of ground phosphate rock=1: 0.05~1.0 (weight ratio), add ground phosphate rock and under 60~110 ℃ of temperature, carried out decomposition reaction 1~8 hour, use common process method returning charge granulating and drying then, can make the chloride Nitrogen-Phosphorus-Potassium compound fertilizer of solid.The advantage of this technology is fairly obvious, and it not only makes liquid fertilizer become solid with a kind of short-cut method, and has simplified the solid concentrating unit of conventional change, has avoided the etching problem of thickening equipment material, has also increased effective nutrient of phosphorus in the multiple fertilizer of former system.
In addition, with regard to the whole technical proposal that the present invention proposes, it also has the following advantages and positively effect:
1, because the raw material that the present invention uses is the slips after neutralization, concentrated two steps purify, add the further purification of water logging, the removal of impurity height, thereby can make high purity (〉=98%), pure phosphoric acid-the ammonium of low rate of moisture absorption (≤2%), and constant product quality, can do industry, the raw material that especially fire-fighting ABC powder extinguishing agent is used.
2, because the technology of the present invention route is reasonable, design ingeniously, not only noiseless, also increased the fertilizer new variety fertilizer grade phosphorus ammonium production system, and the generation of whole technological process no waste.
3, under the situation that does not increase too much investment, can obtain the high polynary multiple fertilizer of serial added value, wherein not only contain nitrogen, phosphorus, potassium, also contain nutrients such as sulphur, and the ratio of each component more is tending towards reasonable for plant-growth.
4, owing to less investment of the present invention, the technological process no waste generates, product (industrial ammonium phosphate and series compound fertilizer) added value height, and production does not have influence again to fertilizer grade phosphorus ammonium, thereby has remarkable economic efficiency and social benefit.
Accompanying drawing is the main device synoptic diagram of the used flow process of the present invention.
Provide embodiment below in conjunction with accompanying drawing
Embodiment one:
Present embodiment adopts flow path device shown in the drawings.
At first 2200g is contained P
2O
5About 24% enriching slurry is put into leaching groove 1, and again by slurry: water=1: the proportioning 0.7(weight ratio) adds water, and 95 ℃ are stirred leaching 20 minutes down.Then it is sent in the separating machine 2 and separate, obtain the scavenging solution of phosphoric acid-ammonium and ammonium sulfate and contain the mud that does not dissolve body refuse.Mud is sent the concentration section of fertilizer grade phosphorus ammonium production system back to.Scavenging solution is then sent into thickener 3, and with conventional evaporating and concentrating process it being concentrated into proportion is 1.34(80 ℃) after, send into again and carry out crystallisation by cooling in the crystallisation by cooling groove 4, at this moment ammonium phosphate is separated out crystallization gradually under cooling conditions.Material after the crystallization sent into again in the separating machine 5 separate, it is dry 6 that the suitable washing of isolated crystal is sent to again, promptly obtains the 200g industrial grade acid-ammonium.The main quality index of its product is: P
2O
560.20%, N11.87%(water content~1%), rate of moisture absorption 0.73%.
Mother liquor 840g behind the separation ammonium phosphate crystal sends into reactive tank 7, presses NH
3/ K=1.3(mol ratio) adding concentration is 16% the KCl aqueous solution, under 90 ℃, carry out conversion reaction 3 hours, send into then in crystallisation by cooling in the crystallisation by cooling groove 8, the separating machine 9 and separate, the solid phase drying 10 after the separation promptly makes finished product-one-level does not have chlorine Nitrogen-Phosphorus-Potassium compound fertilizer 250g.Group of products becomes: N4.38%, P
2O
522.80%, K
2O 32.55%, SO
321.95%, Cl
-1.61%(Cl
-Content≤2.5% is called no chlorine fertilizer).This product is owing to belong to no chlorine fertilizer, thereby can extensively be applied to fear-chlorion crop, as the tobacco in the cash crop, citrus etc.
Isolating mother liquor 1040g remaining behind the chlorine-free compound fertilizer enters mother liquor and awards groove 11(and form: P
2O
58.28%, K
2O 8.18%, N4.95%, SO
31.69%, Cl
-12.93%), can be directly multiple fertile as liquid, also can use with other solid fertilizer blending, can also further process according to method provided by the invention: be about to mother liquor and send into reactive tank 12, and press mother liquor: ground phosphate rock=1: the 0.12(weight ratio) add ground phosphate rock, under 80 ℃, carry out decomposition reaction 2 hours, use common process method returning charge granulating and drying 13 then, promptly make chloride Nitrogen-Phosphorus-Potassium compound fertilizer 640g.Its group of products becomes: effective P
2O
517.58%, N7.99%, K
2O 13.28%, SO
32.75%, Cl
-21.01%.
Embodiment two:
Present embodiment still adopts flow path device shown in the drawings.
1840g is contained P
2O
5About 26% enriching slurry is put into leaching groove 1, adds slurry again: water=1: the water 0.5(weight ratio), stir leaching 40 minutes down in 80 ℃, and send in the separating machine 2 and separate, obtain the scavenging solution of phosphoric acid-ammonium and ammonium sulfate and contain the mud that does not dissolve body refuse.The concentration section of mud foldback fertilizer grade phosphorus ammonium production system.Scavenging solution is then sent into thickener 3, is concentrated into proportion 1.27(80 ℃) after, send into again and carry out crystallisation by cooling in the crystallisation by cooling groove 4, separate in the separating machine 5.Drying 6 is delivered in the suitable washing of isolated crystal again, can obtain the 200g industrial grade acid-ammonium.The main quality index of product is: P
2O
559.93%, N 11.68%(water content~1%), rate of moisture absorption 1.24%.
Separate the mother liquor 1000g behind the ammonium phosphate crystal, sent into reactive tank 7, met NH
3/ K=3.0(mol ratio) adding concentration is 30% the KCl aqueous solution, under 75 ℃, carry out conversion reaction 4 hours, send into crystallisation by cooling in the crystallisation by cooling groove 8 then, separate in the separating machine 9, the solid phase drying after the separation promptly makes the free from chloride Nitrogen-Phosphorus-Potassium compound fertilizer 264g of one-level.Group of products becomes: N 7.87%, P
2O
534.63%, K
2O 21.69%, SO
320.17%, Cl
-2.24%.
Remaining mother liquor 624g enters mother liquor tank 11(composition: P after isolating chlorine-free compound fertilizer
2O
513.17%, K
2O 4.30%, and N 6.94%, SO
35.09%, Cl
-8.80%), can be directly multiple fertile as liquid, also can use and further to process according to method provided by the invention: be about to mother liquor and send into reactive tank 12 with other solid fertilizer blending, and press mother liquor: ground phosphate rock=1: the 0.3(weight ratio) add ground phosphate rock, under 100 ℃, carry out decomposition reaction 1.5 hours, send returning charge granulating and drying 13 then, promptly make chloride Nitrogen-Phosphorus-Potassium compound fertilizer 445g.Its group of products becomes: effective P
2O
525.26%, N 9.69%, K
2O 6.05%, SO
37.14%, Cl
-12.28%.