CN101798240A - Method for preparing urea gypsum fertilizer by ball milling of gypsum - Google Patents

Method for preparing urea gypsum fertilizer by ball milling of gypsum Download PDF

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CN101798240A
CN101798240A CN201010130179A CN201010130179A CN101798240A CN 101798240 A CN101798240 A CN 101798240A CN 201010130179 A CN201010130179 A CN 201010130179A CN 201010130179 A CN201010130179 A CN 201010130179A CN 101798240 A CN101798240 A CN 101798240A
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gypsum
urea
fertilizer
ball
ball milling
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邓跃全
董发勤
许春凤
解忠雷
何江洪
付鹏
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Southwest University of Science and Technology
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P60/00—Technologies relating to agriculture, livestock or agroalimentary industries
    • Y02P60/20—Reduction of greenhouse gas [GHG] emissions in agriculture, e.g. CO2
    • Y02P60/21—Dinitrogen oxide [N2O], e.g. using aquaponics, hydroponics or efficiency measures

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Abstract

The invention discloses a method for preparing a urea gypsum fertilizer by ball milling of gypsum, which is characterized by comprising the following steps: preparing urea gypsum from hypsum and urea, and exceeding 1 to 2 weight percent of the use amount of Ca2SO4.2H2O in a stoichiometric ratio of the Ca2SO4.2H2O to CO(NH4)2 in reaction; converting the Ca2SO4.2H2O content in the gypsum into required use amount of gypsum and urea; and putting the raw materials into a ball mill, performing ball milling in a ratio of grinding media to material of 3-5, and performing ball milling reaction at normal temperature for 20 to 40 minutes to prepare the urea gypsum fertilizer. The method has the advantages of quick reaction at normal temperature, low energy consumption, high efficiency, continuous production and strong practicability; and the solubility of the prepared urea gypsum is about 3.5 percent of that of urea, the dissolution rate and nutrient release rate are much lower than those of the urea, and the urea gypsum has good slow release effect and is a high-efficiency high-quality slow release nitrogen fertilizer.

Description

Gypsum sphere grinds the standby method of making the urea gypsum of fertilizer
Technical field
The present invention relates to a kind of fertilizer, relate to a kind of gypsum sphere and grind the standby method of making the urea gypsum of fertilizer.Belong to novel comprehensive utilization of resources and power-saving technology and product scope in new forms of energy and the high-efficiency energy-saving technology.This product urea gypsum mainly as nitrogen fertilizer in agriculture, has the good slow release effect, can be used as slow release fertilizer, also can be used as the raw material for preparing release and release control fertilizer, can effectively improve utilization rate of fertilizer, increase grain yield, reduce the discharging of nitrogen, reduce its eutrophication pollution water.
Background technology
Urea is the nitrogen fertilizers of worldwide turnout, sales volume and amount of application maximum, but because a lot of regional fertilization modes are improper, and the leaching loss of nitrogen, volatilization, infiltration and effect such as fixing, causing utilization rate of nitrogen fertilizer only is 20～35%, low utilization rate of fertilizer not only causes enormous economic loss, also can cause serious eutrophication pollution to water bodys such as river, river, lakes.
Slow control fertilizer has become the research direction that has development prospect in all kinds of fertilizer owing to have utilization rate of fertilizer height, environmental friendliness, can realize disposable heavy dressing and improve advantages such as crops quality and output.Thiourea slow release fertilizer can be divided into two classes by production technology at present: the one, and coated carbamide at urea outer wrap one deck organic polymer, slows down or reduces the dissolution rate of urea molecule.The 2nd, modification urea, urea and organic compound generate the microsolubility nitrogenous compound through condensation reaction, meet behind the water slowly that hydrolysis restores into urea, as urea formaldehyde, IBDU etc.This two classes slow release fertilizer complex manufacturing, the cost height, its price is that conventional fertilizer is high more than 3～5 times, secondly also can cause secondary pollution.
The urea gypsum is the compound that 4 molecule urea replace crystal water gained in the gypsum, and molecular formula is CaSO 44CO (NH 2) 2, its nitrogen content is 21%, and is suitable with ammonium sulfate.Urea gypsum dissolution degree is lower, and in the time of 30 ℃, the solubleness in the water is 3.67g, is 3.5% of urea, so the dissolving of urea gypsum and nutrient release rate be far smaller than urea, has the good slow release effect, is a kind of slow-release nitrogen fertilizer of high-efficiency high-quality.
The urea gypsum is because itself lower solubleness, do not need coating or modification, can discharge urea slowly, be the needs that can satisfy each growth phase of crop, can not cause the burning seedling again, can also improve utilization rate of fertilizer, reduce the loss of nitrogen because of excessive concentration, increase crop yield, alleviate environmental pollution.
In the prior art, the urea synthesis gypsum generally has two kinds of methods, promptly cools off liberation method and scorification.The cooling liberation method is at the urea saturated aqueous solution of getting in the beaker under the 20mL room temperature, adds 8 gram urea, is heated to 80 ℃ in water-bath, stirs to make it to dissolve fully.In this solution, add 5 gram terra alba (gypsum) powder, and stir.Be heated to 80 ℃ and keep for some time after slowly cooling, drop to room temperature after making several hours, place one night after-filtration, wash with alcohol.Industrial urea and the gypsum of then making reacted under molten state 1 hour, can make the urea gypsum.
The shortcoming and defect that prior art for preparing urea gypsum exists:
(1) the cooling liberation method is to add a spot of gypsum in the supersaturated solution of urea, though made the urea gypsum, with respect to the consumption of urea and productive rate low.Long reaction time needs heating, complex procedures, and investment is big, and power consumption is big, and production capacity is low;
(2) scorification prepares the urea gypsum, temperature of reaction height not only, and energy consumption is big, and to the equipment requirements harshness, investment is big, is difficult to realize scale operation.
Gypsum resource comprises phosphogypsum, desulfurated plaster and the plaster of paris etc., total retained reserve ore 57,600,000,000 t of Chinese gypsum resource, and year produced quantity 30,000,000 t all rank first in the world.Phosphogypsum is the industrial solid by product that is discharged when being the raw material Wet-process phosphoric acid (WPPA) with ground phosphate rock, its main component is a terra alba, content is about 90%, it is acid that phosphogypsum is, the pH value is generally 1～4.5, and contain the required phosphorus of plant growth, sulphur, calcium, silicon, zinc, magnesium, nutrients such as iron can be improved alkaline earth by instead of gypsum, flower alkaline earth and solonchak, improve the soil physicochemical character and microbial activities condition, increase soil fertility, phosphogypsum also can be used as sulfur fertilizer and calcareous fertilisers use, at present, and about 1,500,000,000 tons of world row phosphogypsum, year is arranged 5,000 ten thousand tons by China, several hundred million tons are stacked in China's accumulation, global phosphogypsum utilization ratio 4.3～4.6%, and China is 2%～3%; Desulfurated plaster is the industrial by-products that flue gas desulphurization produces, estimate that China's 2010 output are 2,000 ten thousand tons, all realize desulfurization as thermal power plant, annual production can reach 4,000 ten thousand tons, and accumulation was at present stacked hundred million tons, and its main component is a terra alba, content is greater than 90%, and plaster of paris sulfate dihydrate calcium contents is generally 70～80%, and phosphogypsum and desulfurated plaster are industrial residues anxious to be utilized in addition, so phosphogypsum and desulfurated plaster must fully utilize economy, environment and social effect are more arranged.
Summary of the invention
Purpose of the present invention is intended to overcome deficiency of the prior art, with gypsum (comprising phosphogypsum, desulfurated plaster, the plaster of paris) and urea is raw material, by the mode of ball milling, provide that a kind of technology is simple, investment gypsum sphere little, that speed is fast, output is high, energy consumption is little, cost is low grinds the standby method of making the urea gypsum of fertilizer.
Content of the present invention is: a kind of gypsum sphere grinds the standby method of making the urea gypsum of fertilizer, and its feature part is to comprise the following steps:
A, batching: get raw material gypsum, urea; According to Ca 2SO 42H 2O and CO (NH 4) 2The stoichiometric ratio of chemical reaction is with Ca 2SO 42H 2The consumption of O is excessive by weight percentage 1%～20% (that is: presses Ca 2SO 42H 2The theory of O is got Ca with 101%～120% of weight 2SO 42H 2The O batching); Press the Ca in the gypsum 2SO 42H 2O content is converted to the consumption of required gypsum and urea;
Described Ca 2SO 42H 2O and CO (NH 4) 2Chemical equation as follows:
CaSO 4·2H 2O+4CO(NH 2) 2＝CaSO 4·4CO(NH 2) 2+2H 2O；
B, ball milling preparation: adopt the method for ball milling preparation, by gypsum and urea production urea gypsum; That is: be 3～5 to get abrading-ball and drop in the ball mill earlier, again gypsum, urea dropped in the ball mill, at normal temperatures, behind ball-milling reaction 20min～40min, promptly make urea gypsum product as fertilizer by the weight ratio of ratio of grinding media to material.
In the content of the present invention: described gypsum can be phosphogypsum, desulfurated plaster or the plaster of paris.
In the content of the present invention: the described urea gypsum product of making fertilizer that makes usefulness can also drying be handled, for example: dry, dry etc., the same prior art of method.
In the content of the present invention: the method for calculation of described raw material gypsum and amount of urea proportioning, for example: if Ca in the raw material gypsum 2SO 42H 2O content is
Figure GSA00000060894100031
The excessive N% of the consumption of gypsum, then:
Figure GSA00000060894100041
In the formula: m GypsumBe the consumption (weight, back are together) of raw material gypsum,
Figure GSA00000060894100042
Be Ca 2SO 42H 2The consumption of O, m UreaWith
Figure GSA00000060894100043
Be the consumption of urea,
Figure GSA00000060894100044
Be Ca 2SO 42H 2The molar mass of O,
Figure GSA00000060894100045
Be the molar mass of urea,
Figure GSA00000060894100046
Be Ca in the gypsum 2SO 42H 2The percentage composition of O, N are the excessive weight percent of gypsum, are 1%～20%.To call this formula in the following text is formula (1).
Compared with prior art, the present invention has following characteristics and beneficial effect:
(1) the present invention adopts the ball milling power-saving technology, and under ball action, the gypsum powder is disperseed fully, fully contacts with urea molecule, and rapid reaction under the effect of mechanical energy, transforms to generate the urea gypsum.Compare with the method for traditional industrial production urea gypsum, the present device investment is little, and working condition requires low, and technology is simple, the material treatment capacity is big, very easily realizes suitability for industrialized production, and it is fast to have speed, the productive rate height, energy consumption is low, characteristics such as efficient height, practical characteristics;
(2) gypsum itself contains the required various nutritive substances of crop, can directly be used as sulfur fertilizer, calcareous fertilisers and soil improvement agent, and the present invention carries out ball-milling reaction with gypsum and urea, generates the urea gypsum, gives its good slow control performance.Under these two kinds of factor synergies, the urea gypsum of the present invention's preparation can obviously improve utilization rate of fertilizer, lowers fertilizer amount, improves crop yield;
In a word, it is simple to the invention provides a kind of technology, energy consumption is low, time is short, the fertilizer ball milling technology of preparing that productive rate is high, prepared with low cost, utilization rate of fertilizer is high, the urea gypsum of obvious effect of increasing production, simultaneously also opens up a new effective way for extensive efficient utilization of phosphogypsum and desulfurated plaster, particularly also do not have under its situation of utilizing technology on a large scale, its meaning is more outstanding.
Embodiment
Embodiment given below intends so that the invention will be further described; but can not be interpreted as it is limiting the scope of the invention; the person skilled in art to some nonessential improvement and adjustment that the present invention makes, still belongs to protection scope of the present invention according to the content of the invention described above.
Embodiment 1:
A kind of phosphogypsum ball grinds the standby method of making the urea gypsum of fertilizer, comprises the following steps:
A, batching: get Ca 2SO 4.2H 2The weight percentage of O is that 90.00% phosphogypsum, urea are raw material; According to Ca 2SO 4.2H 2O and CO (NH 2) 2The stoichiometric ratio of reaction is with Ca 2SO 4.2H 2Excessive 5% (the weight %, the back together) of the consumption of O; Press the Ca in the phosphogypsum 2SO 4.2H 2O content is converted to the quality of required phosphogypsum and urea;
The consumption m of phosphogypsum in the batching PhosphogypsumThe consumption m of (weight, back are together) and urea UreaRatio calculate through formula (1) and be as can be known:
m Phosphogypsum/ m Urea=0.84
B, ball-milling reaction: phosphogypsum, urea are dropped in the ball mill, are 3 input abrading-balls by ratio of grinding media to material (weight ratio), and at normal temperatures, behind the ball-milling reaction 20min, (can be dried) promptly makes the urea gypsum product as fertilizer again.
Embodiment 2～7:
A kind of phosphogypsum ball grinds the standby method of making the urea gypsum of fertilizer, and step is with embodiment 1, the consumption m of phosphogypsum in the batching PhosphogypsumThe consumption m of (weight, back are together) and urea UreaPart by weight be the material proportioning, and other has related parameter to see the following form:
The embodiment numbering Material proportioning (m Phosphogypsum∶m Urea) Ratio of grinding media to material Reaction times/min Urea gypsum productive rate/%
??2 ??0.84 ??3 ??20 ??83.12
The embodiment numbering Material proportioning (m Phosphogypsum∶m Urea) Ratio of grinding media to material Reaction times/min Urea gypsum productive rate/%
??3 ??0.84 ??4 ??30 ??82.24
??4 ??0.88 ??4 ??40 ??80.65
??5 ??0.88 ??5 ??20 ??84.36
??6 ??0.92 ??5 ??30 ??76.95
??7 ??0.92 ??3 ??40 ??79.64
Annotate: used phosphogypsum is the Chuan Xi product among interior each embodiment of table, contains Ca 2SO 4.2H 2The weight percentage of O is 90.00%.
Embodiment 8:
A kind of desulfurated plaster ball milling preparation comprises the following steps: as the method for the urea gypsum of fertilizer
A, batching: get Ca 2SO 4.2H 2The weight percentage of O is that 92.00% desulfurated plaster, urea are raw material; According to Ca 2SO 4.2H 2O and CO (NH 2) 2The stoichiometric ratio of reaction is with Ca 2SO 4.2H 2Excessive 10% (the weight %, the back together) of the consumption of O; Press the Ca in the desulfurated plaster 2SO 4.2H 2O content is converted to the quality of required desulfurated plaster and urea;
The consumption m of desulfurated plaster in the batching Desulfurated plasterThe consumption m of (weight, back are together) and urea UreaRatio calculate through formula (1) and be as can be known:
m Desulfurated plaster/ m Urea=0.86
B, ball-milling reaction: desulfurated plaster, urea are dropped in the ball mill, are 3 input abrading-balls by ratio of grinding media to material (weight ratio), and at normal temperatures, behind the ball-milling reaction 20min, (can be dried) promptly makes the urea gypsum product as fertilizer again.
Embodiment 9～14:
The preparation of a kind of desulfurated plaster ball milling is as the method for the urea gypsum of fertilizer, and step is with embodiment 8, the consumption m of desulfurated plaster in the batching Desulfurated plasterThe consumption m of (weight, back are together) and urea UreaPart by weight be the material proportioning, and other has related parameter to see the following form:
The embodiment numbering Material proportioning (m Desulfurated plaster∶m Urea) Ratio of grinding media to material Reaction times/min Urea gypsum productive rate/%
??9 ??0.82 ??3 ??20 ??87.32
??10 ??0.82 ??4 ??30 ??88.56
The embodiment numbering Material proportioning (m Desulfurated plaster∶m Urea) Ratio of grinding media to material Reaction times/min Urea gypsum productive rate/%
??11 ??0.86 ??4 ??40 ??82.57
??12 ??0.86 ??5 ??20 ??80.64
??13 ??0.90 ??5 ??30 ??86.93
??14 ??0.90 ??3 ??40 ??84.29
Annotate: used desulfurated plaster contains Ca among interior each embodiment of table 2SO 4.2H 2The weight percentage of O is 92.00%.
Embodiment 15:
A kind of plaster of paris ball milling preparation comprises the following steps: as the method for the urea gypsum of fertilizer
A, batching: get Ca 2SO 4.2H 2The weight percentage of O is that 75.00% the plaster of paris, urea are raw material; According to Ca 2SO 4.2H 2O and CO (NH 2) 2The stoichiometric ratio of reaction is with Ca 2SO 4.2H 2Excessive 15% (the weight %, the back together) of the consumption of O; Press the Ca in the plaster of paris 2SO 4.2H 2O content is converted to the quality of the required plaster of paris and urea;
The consumption m of the plaster of paris in the batching The plaster of parisThe consumption m of (weight, back are together) and urea UreaRatio calculate through formula (1) and be as can be known:
m The plaster of paris/ m Urea=1.10
B, ball-milling reaction: the plaster of paris, urea are dropped in the ball mill, are 3 input abrading-balls by ratio of grinding media to material (weight ratio), and at normal temperatures, behind the ball-milling reaction 20min, (can be dried) promptly makes the urea gypsum product as fertilizer again.
Embodiment 16～21:
The preparation of a kind of plaster of paris ball milling is as the method for the urea gypsum of fertilizer, and step is with embodiment 15, the consumption m of the plaster of paris in the batching The plaster of parisThe consumption m of (weight, back are together) and urea UreaPart by weight be the material proportioning, and other has related parameter to see the following form:
The embodiment numbering Material proportioning (m The plaster of paris∶m Urea) Ratio of grinding media to material Reaction times/min Urea gypsum productive rate/%
??16 ??1.00 ??3 ??20 ??80.78
??17 ??1.00 ??4 ??30 ??79.67
??18 ??1.05 ??4 ??40 ??80.05
??19 ??1.05 ??5 ??20 ??78.29
The embodiment numbering Material proportioning (m The plaster of paris∶m Urea) Ratio of grinding media to material Reaction times/min Urea gypsum productive rate/%
??20 ??1.10 ??5 ??30 ??75.93
??21 ??1.10 ??3 ??40 ??78.48
Annotate: the used plaster of paris contains Ca among interior each embodiment of table 2SO 4.2H 2The weight percentage of O is 75.00%.
The invention is not restricted to the foregoing description, content of the present invention is described all can implement and have described good result.

Claims (2)

1. a gypsum sphere grinds the standby method of making the urea gypsum of fertilizer, it is characterized in that comprising the following steps:
A, batching: get raw material gypsum, urea; According to Ca 2SO 42H 2O and CO (NH 4) 2The stoichiometric ratio of chemical reaction is with Ca 2SO 42H 2The consumption of O excessive by weight percentage 1%～20%; Press the Ca in the gypsum 2SO 42H 2O content is converted to the consumption of required gypsum and urea;
Described Ca 2SO 42H 2O and CO (NH 4) 2Chemical equation as follows:
CaSO 4·2H 2O+4CO(NH 2) 2＝CaSO 4·4CO(NH 2) 2+2H 2O；
B, ball milling preparation: adopt the method for ball milling preparation, by gypsum and urea production urea gypsum; That is: be 3～5 to get abrading-ball and drop in the ball mill earlier, again gypsum, urea dropped in the ball mill, at normal temperatures, behind ball-milling reaction 20min～40min, promptly make urea gypsum product as fertilizer by the weight ratio of ratio of grinding media to material.
2. grind the standby method of making the urea gypsum of fertilizer by the described gypsum sphere of claim 1, it is characterized in that: described gypsum is phosphogypsum, desulfurated plaster or the plaster of paris.
CN201010130179A 2010-03-23 2010-03-23 Method for preparing urea gypsum fertilizer by ball milling of gypsum Pending CN101798240A (en)

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102167650A (en) * 2011-01-27 2011-08-31 西南科技大学 Preparation method of gypsum-based urea gypsum-urea-ammonium sulphate controlled-release nitrogen fertilizers
CN103086781A (en) * 2013-01-23 2013-05-08 浙江大学 Method for preparing urea ardealite by solution crystallization method taking ardealite as raw material
CN103086810A (en) * 2013-01-23 2013-05-08 官宝红 Method for preparing urea gypsum by taking desulfurized gypsum as raw material and using solution crystallization method
CN103172288A (en) * 2013-03-07 2013-06-26 云南磷化集团有限公司 Phosphogypsum pretreatment method
CN103333033A (en) * 2013-06-24 2013-10-02 西南科技大学 Preparation method of low formaldehyde resin-gypsum-bentonite-based controlled release fertilizer
CN111051269A (en) * 2017-07-21 2020-04-21 沙特基础工业全球技术公司 Calcium sulfate urea granules and methods of making and using same
CN111491907A (en) * 2017-08-21 2020-08-04 理海大学 Solvent-free process for producing urea adducts
CN111499462A (en) * 2020-06-10 2020-08-07 黑龙江实力农业肥料科技有限公司 Preparation method of medium-trace element coated fertilizer

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1066051A (en) * 1991-04-25 1992-11-11 李江华 The method for making of active superphosphate fertilizer
CN1069015A (en) * 1991-07-30 1993-02-17 昆明化工技术开发研究所 Silicophosphate fertilizer and manufacture method thereof
CN101585547A (en) * 2009-06-23 2009-11-25 西南科技大学 Method for preparing ammonium sulfate as fertilizer by phosphogypsum through ball milling

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1066051A (en) * 1991-04-25 1992-11-11 李江华 The method for making of active superphosphate fertilizer
CN1069015A (en) * 1991-07-30 1993-02-17 昆明化工技术开发研究所 Silicophosphate fertilizer and manufacture method thereof
CN101585547A (en) * 2009-06-23 2009-11-25 西南科技大学 Method for preparing ammonium sulfate as fertilizer by phosphogypsum through ball milling

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102167650A (en) * 2011-01-27 2011-08-31 西南科技大学 Preparation method of gypsum-based urea gypsum-urea-ammonium sulphate controlled-release nitrogen fertilizers
CN103086781B (en) * 2013-01-23 2014-07-30 浙江大学 Method for preparing urea ardealite by solution crystallization method taking ardealite as raw material
CN103086781A (en) * 2013-01-23 2013-05-08 浙江大学 Method for preparing urea ardealite by solution crystallization method taking ardealite as raw material
CN103086810A (en) * 2013-01-23 2013-05-08 官宝红 Method for preparing urea gypsum by taking desulfurized gypsum as raw material and using solution crystallization method
CN103172288A (en) * 2013-03-07 2013-06-26 云南磷化集团有限公司 Phosphogypsum pretreatment method
CN103333033B (en) * 2013-06-24 2015-08-05 西南科技大学 The preparation method of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer
CN103333033A (en) * 2013-06-24 2013-10-02 西南科技大学 Preparation method of low formaldehyde resin-gypsum-bentonite-based controlled release fertilizer
CN111051269A (en) * 2017-07-21 2020-04-21 沙特基础工业全球技术公司 Calcium sulfate urea granules and methods of making and using same
US11299441B2 (en) 2017-07-21 2022-04-12 Sabic Global Technologies B.V. Calcium sulfate urea granules and methods for producing and using the same
US11352306B2 (en) 2017-07-21 2022-06-07 Sabic Global Technologies B.V. Calcium sulfate urea granules and methods for producing and using the same
US11802096B2 (en) 2017-07-21 2023-10-31 Sabic Global Technologies B.V. Calcium sulfate urea granules and methods for producing and using the same
US11912634B2 (en) 2017-07-21 2024-02-27 Sabic Global Technologies B.V. Calcium sulfate urea granules and methods for producing and using the same
CN111491907A (en) * 2017-08-21 2020-08-04 理海大学 Solvent-free process for producing urea adducts
CN111499462A (en) * 2020-06-10 2020-08-07 黑龙江实力农业肥料科技有限公司 Preparation method of medium-trace element coated fertilizer

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Application publication date: 20100811