CN103333033A

CN103333033A - Preparation method of low formaldehyde resin-gypsum-bentonite-based controlled release fertilizer

Info

Publication number: CN103333033A
Application number: CN2013102522321A
Authority: CN
Inventors: 邓跃全; 董发勤; 李娜; 李丽娟; 罗绍东; 邓智友
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2013-06-24
Filing date: 2013-06-24
Publication date: 2013-10-02
Anticipated expiration: 2033-06-24
Also published as: CN103333033B

Abstract

The invention discloses a preparation method of a low formaldehyde resin-gypsum-bentonite-based controlled release fertilizer. The preparation method is characterized by comprising the steps of: preparing an ammonium sulfate master batch, preparing a urea gypsum master batch, preparing bentonite, preparing hemihydrate gypsum, and preparing a low formaldehyde resin-gypsum-bentonite compound/mixed controlled-release fertilizer. According to the preparation method, the low formaldehyde resin-gypsum composite material is used as an adhesive and is compounded with the bentonite to form a controlled-release system, and the low formaldehyde resin-gypsum-bentonite-based controlled release fertilizer is prepared by using an integrated preparation technology of extruding and mixing reaction, vibrating and sieving and disc pelleting. The preparation method has the characteristics of low energy consumption, low formaldehyde content, high controlled release nitrogen content, and the like; the prepared controlled-release fertilizer is capable of remarkably increasing the yield of grains, increasing the utilization rate and reducing the environment pollution caused by agricultural emission; meanwhile, an effective path is provided for comprehensive utilization of industrial gypsum.

Description

The preparation method of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer

Technical field

The invention belongs to fertilizer, relate to the preparation method of a kind of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.Low urea formaldehyde resin-gypsum-bentonite base the slow release fertilizer of the present invention's preparation is suitable for makes agrochemical, contains slow and quick-acting nitrogen composition; The present invention with urea-formaldehyde resin-semi-hydrated gypsum multiple/to mix material be sizing agent, composite with wilkinite again, form slow-releasing system, by the extruding hybrid reaction, vibrosieve, the granulating integrated technology of preparing of disk is prepared, obtain low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer, the whole release rate of fertiliser granulates is reduced, thereby also reach the slowly-releasing of phosphorus, potassium, its fertilizer nutrient rate of release and crop nutrition content absorbing rule are complementary, can effectively improve utilization rate of fertilizer, reduce chemical fertilizer to the pollution of environment, more remarkable to the increasing crop yield effect.

Background technology

Chemical fertilizer is the material guarantee of agricultural sustainable development, be the basis of increases in grain production, at present, China has become maximum in the world chemical fertilizers production state and country of consumption, yet, according to mensuration: utilization rate of nitrogen fertilizer is 25%～40% only in the general chemical fertilizer of China, and phosphate fertilizer has only 10%～25%, and potash fertilizer is 30%～50%, the utilization ratio of chemical fertilizer is lower, cause the manure resources waste, cause the eutrophication pollution of water, increase agriculture production cost.Therefore, exploitation can improve utilization rate of fertilizer to greatest extent, reduces discharging, can obtain the gentle control of the slowly-releasing fertiliser production new technology of high yield again, for ensure grain security, preserving the ecological environment is extremely important.

Slow release fertilizer mainly comprises two big classes, one class is the slow release fertilizer of making by chemical reaction, general solubleness in water is very little, after being manured into soil, under factor effect chemistry and biology, fertilizer decomposes gradually, slowly releases nutrient, as slightly soluble organic nitrogenous fertilizers such as urea formaldehyde, iso-butylene diureas, slightly soluble inorganic nitrogenous fertilizers such as metal phosphorus ammonium salt, partial acidification phosphoric acid salt etc.; Another kind of is the release and release control fertilizer of making by the parcel mode; be to be core with the granular chemical fertilizer; the top layer applies inorganic substance or the organic polymer of one deck low water solubility or microsolubility; decompose gradually by coating diffusion or coating and to discharge nutrient; as organic polymer coated fertilizers such as thermohardening resin coated fertilizer, thermoplastic resin membrane wrapping fertilizer, inorganic coated fertilizers such as sulfur coated urea, mineral substance coat fertilizer etc.Though output and the usage quantity of slowly/controlled releasing fertilizer increase year by year, relative with market value higher because of its production cost, can't be widely accepted at present, compare the very little ratio that is still with normally used quick-acting chemical fertilizer.

Urea-formaldehyde resin is the thermosetting polymer tackiness agent that is passed through addition and polycondensation generation by urea and formaldehyde under katalysis.At present, be mainly used in the production of wood-based plate and the preparation of slow release fertilizer etc. in China.In recent years, people have carried out a large amount of research to the condition of closing of urea-formaldehyde resin, studies show that its preparation technology is: Urea: formaldehyde=1.0:1.0～1.0:1.4;

Divide 3～4 times and add urea;

Temperature of reaction is more than 80 degrees centigrade;

Reaction times 90～180min.Existing processing condition urea is higher with the mol ratio of formaldehyde, main consideration be the cohesive strength of urea-formaldehyde resin, the content of free formaldehyde is higher, temperature of reaction is more than 80 degrees centigrade in addition, the energy consumption height, the time is long, complicated operation, reaction process is wayward.

The urea formaldehyde slow-release compound fertilizer is that urea and methyl alcohol condensation reaction at high temperature generate colloid mixture, with phosphate fertilizer and the synthetic granulation of potash fertilizer, the slow-release compound fertilizer of formation belongs to the high-end product in the fertilizer again, because cost is higher, mainly is used on golf course lawn and the high-grade view flowers.Urea formaldehyde is ripe slow release fertilizer, has just proposed more complete procedure of laboratory abroad as far back as the later stage thirties 20th century.Nineteen fifty-five, German BASF AG carries out commercialization production.1984, USSR (Union of Soviet Socialist Republics) has added vitriolate of tartar to improve sand ground water-retentivity in the urea formaldehyde fertilizer report.Nineteen ninety, the Worsley. Michael of the U.S. has synthesized solid-state urea aldehyde slow release fertilizer with Paraformaldehyde 96 and urea reaction.Recently, Japan's development excess of export slow urea formaldehyde nitrogenous fertilizer, UF urea combination-vitriolate of tartar-phosphorus-ammonium compound fertilizer material; The U.S. has then developed the urea aldehyde disperse fertilizer with package stability, and by urea formaldehyde and phosphoric acid-synthetic high molecular slow-release composite fertilizer of potassium primary phosphate mixed solution reaction.At present, China also is in the starting stage for the development of urea formaldehyde slowly/controlled releasing fertilizer, after 1971 develop the urea formaldehyde slow release fertilizer, does not obtain very fast development in the long term.The complex manufacturing of urea formaldehyde slowly/controlled releasing fertilizer a little less than the research relative thin of key equipment and process matching, is difficult to form industrial scaleization.Urea formaldehyde composite fertilizer master has two kinds, and a kind of is with bread one deck urea-formaldehyde resin outside the composite fertilizer, and plays the slow/controlled release effect, claims urea-formaldehyde resin dressing composite fertilizer; Another kind is that powdery urea resin is joined in the raw material of production composite fertilizer, and the composite fertilizer of production claims built-in urea formaldehyde composite fertilizer.

Composite fertilizer's nutritive element kind is more, and nutrient content is higher, and for balance fertilizing, improving utilization rate of fertilizer has very important effect.Particle is generally made more by composite fertilizer, and water absorbability is little, and prevented from caking is convenient to store and use.The Technology of China production composite fertilizer mainly contains:

Slurry process: be raw material with phosphoric acid, ammonia, utilize neutralizer, tubular reactor will in and slip in the ammoniation and granulation device, carry out coating granulation, add part nitrogen and potassium element etc. in process of production; Part slurry process: directly spray in the tablets press bed with urine or ammonium nitrate strong solution, carry out coating granulation with other solid base fertilizer.

The solid granulating method: be raw material with the monomer base fertilizer, after being crushed to certain fineness, material carries out agglomeration granulation by humidification, heating in the rolling bed of tablets press.

Blending method: be raw material with various nitrogen, phosphorus, each solid base fertilizer of potassium that obvious chemical reaction, granularity and circularity basically identical do not take place, be mixed with the bulk blended fertilizer that nutrient is evenly distributed by certain mixing method.Shape and the specification of China's base fertilizer still do not possess this condition at present. Extrusion process: extruder grain is the non-slurry pelletizing process that solid materials relies on external pressure to reunite. Melting method: utilize the intermediates urea soln of urea plant, be equipped with phosphorus ammonium, sylvite, the production technology-fused mass granulating technique of preparation urea-base compound fertilizer.Fused mass granulating technique is applied in chemical fertilizers production, as the tower sprinkling pelleting of urea, the tower sprinkling pelleting of ammonium nitrate etc.But this technology still belongs to blank for the manufacture of urea-base compound fertilizer at home.These preparation technologies generally adopt the stirring-type hybrid technology to carry out the mixed chemical reaction process, and churning time is long, and energy consumption is big.At present, China advanced person's production technology and equipment are mainly by external introduction, though these technology and equipments have been played important pushing effect to starting and the development of the multiple fertile industry of phosphorus of China.

The gypsum resource of China is extremely abundant, nearly 60,000,000,000 tons of explored natural crystal reserves, rank first in the world, about 2,000 ten thousand tons/year of the plaster of paris of having exploited at present, in addition, along with the contemporary Chinese industrial expansion, to discharge about 3,000 ten thousand tons industrial gypsum (industry by-product gypsum) every year, mainly be phosphogypsum and desulfurated plaster.Method and the technology of the comprehensive utilization industry by-product gypsum that cost of development is low, treatment capacity is big both be conducive to the guard ring border, again can save energy and resource, and gypsum is rich in calcium, sulphur, and nutritive element such as the necessary phosphorus of plant-growth, magnesium, iron, silicon.Determined that at present gypsum application has plant biomass and the quality of raising, improves soil fertility, delays Soil degradation in agricultural, reduce effects such as heavy metal contamination, be widely used as sulphur, calcareous fertilisers and soil improvement agent, also can produce controlled availability fertilizer with other fertilizer.This seminar is raw material with phosphogypsum and bicarbonate of ammonia, has prepared the ammonium sulfate that is used as fertilizer by the solid phase ball-milling reaction, the calcium sulfate of indissoluble in the phosphogypsum is converted into the ammonium sulfate (patent publication No. CN 101585547A) of solubility; Urea and gypsum solid phase ball-milling reaction have been prepared the urea gypsum as fertilizer, and this fertilizer has from slow-release function, and fertilizer efficiency period is long, than urea utilization ratio higher (patent publication No. CN 101798240A).With urea and the reacted urea gypsum of gypsum masterbatch, the reacted ammonium sulfate masterbatch of bicarbonate of ammonia and gypsum is main raw material, evenly mix certain quantity of additive, prepare controlled nitrogen release rate through granulation, be fit to the gypsum base urea gypsum-urea-sulphur ammonium controlled release nitrogenous fertilizer (patent publication No. CN 102167650A) of Different Crop growth demand.Pre-stage test shows, is the agricultural fertilizer of feedstock production with the gypsum, and volume increase crop that can be is in various degree improved utilization rate of fertilizer, and extensive processing and the application for phosphogypsum and desulfurated plaster simultaneously provides an effective way.

Wilkinite is a kind of tonstein based on montmorillonite, has higher cation exchange capacity, stronger water retention capacity and good agglutinating value(of coal).Wilkinite can be used for improving the soil, and also can be used as the preparing carriers slow-release fertilizer, effectively improves chemical fertilizer utilization ratio, reduces environmental pollution.Explore shows that China's wilkinite proven reserve reach more than 50.87 hundred million tons, account for 60% of world's total amount, occupy first place in the world.Pan Yanfeng etc. utilize adsorptivity mineral wilkinite parcel nitrogen, phosphorus, potash fertilizer to prepare release and release control fertilizer, analytical results shows that encapsulation process do not destroy the effective constituent of fertilizer, and wilkinite has the good slow release effect to Yi Rongfei such as nitrogen, potash fertilizer, and indissoluble fertilizer such as phosphate fertilizer are had the short effect of releasing.Luo Yangpo etc. are carrier with wilkinite and kaolin, adopt polishing to prepare multiple clay base nitrogen, phosphorus, potash fertilizer and composite fertilizer, and with the leaching test evaluation release performance of fertilizer, the result shows that nitrogen, phosphorus, potassium all have sustained release performance preferably in the bentonite base composite fertilizer that makes, with regard to rate of release, the rate of release of nitrogen is the fastest, and potassium takes second place, and phosphorus is the slowest.Li Jinli etc. show the slow-release fertilizer had good sustained release effect that slow-release fertilizer slow release effect that wilkinite and urea are made into is obviously made than rectorite leng clay, attapulgite clay, clinoptilolite to the result of study of several natural porous minerals/slow-release fertilizer of carbamide sustained releasing character.Liu likes that equality research table wilkinite has good controlled-release function to potash fertilizer.Utilize wilkinite as the preparing carriers agricultural fertilizer, can not only fully rationally utilize the effective rate of utilization of Mineral resources, raising fertilizer, can also reduce agriculture production cost, reduce the environmental pollution that the agricultural discharging causes, significant.

Summary of the invention

Purpose of the present invention is intended to overcome deficiency of the prior art, and the preparation method of a kind of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer is provided.The present invention is sizing agent with low urea formaldehyde resin-composite gypsum material, composite with wilkinite again, form slow-releasing system, by the extruding hybrid reaction, vibrosieve, the granulating integrated technology of preparing of disk obtains the method for low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer; Adopt low formaldehyde-urea amount of substance ratio, prepare the low high nitrogen urea-formaldehyde resin of aldehyde under low temperature, weak acid medium condition, it is low to have energy consumption, and formaldehyde content hangs down and the high characteristics that get of slowly-releasing nitrogen, is particularly suitable for the preparation of slow release fertilizer; Urea-formaldehyde resin and semi-hydrated gypsum are mixed with out organic and inorganic compound binding agent as fertilizer in certain proportion, and an amount of wilkinite preparation of remix is as the composite slow release material of fertilizer; Based on this composite slow release material, add slow nitrogenous fertilizer (urea gypsum), instant nitrogenousfertilizer (ammonium sulfate), phosphorus fertilizer or potassium fertilizer (wherein adopted especially by gypsum respectively with bicarbonate of ammonia and urea ammonium sulfate and the urea gypsum by the ball-milling reaction preparation), form the slow release fertilizer system; Because this system very easily forms sticking group, can not be by once extruding or a disk are finished granulation, the present invention proposes by the extruding hybrid reaction, vibrosieve, and the granulating integrated technology of preparing of disk prepares low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer; Urea-formaldehyde resin-semi-hydrated gypsum composite slow release material is the combination of organic-inorganic binder, and the nutrient that can effectively control composite fertilizer discharges; By the extruding, make mixing of materials more even, the reaction more abundant; Gypsum as sizing agent is semi-hydrated gypsum, has water-absorbent, wilkinite also has good water-absorbent, both water regain and urea-formaldehyde resin, ammonium sulfate, urea gypsum material moisture are mated, can make in the whole preparation process and no longer add water, also not needing specially ammonium sulfate, urea gypsum material to be dried, thereby save dried material and the equipment that brings drops into and energy expenditure, is a kind of energy-saving processing technique.

Content of the present invention is: the preparation method of a kind of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer is characterized in that comprising the following steps:

A, preparation ammonium sulfate masterbatch: get gypsum (CaSO42H2O), bicarbonate of ammonia (NH4HCO3) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 5%～20%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 3～5 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 10～15%, at normal temperatures, behind ball-milling reaction 20～60min, namely obtain the ammonium sulfate masterbatch, reaction conversion ratio is more than 95%, and the water content in the ammonium sulfate masterbatch is about 25%;

B, preparation urea gypsum masterbatch: get gypsum (CaSO42H2O), urea (CO (NH4) 2) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 5%～20%; Gypsum, urea are dropped in the ball mill, be 3～5 to drop into abrading-balls by ball material weight ratio, the water that adds raw material gross weight 10～15%, at normal temperatures, behind ball-milling reaction 20～40min, namely obtain urea gypsum masterbatch, reaction conversion ratio is 70～90%, in the urea gypsum masterbatch that makes: urea gypsum attitude nitrogen accounts for 70～90%, and urea nitrogen accounts for 10～30%, and water content is about 18%;

C, preparation wilkinite: get the natural montmorillonite ore deposit, drying or natural air drying are crushed to 60～200 orders again, namely make wilkinite;

D, preparation semi-hydrated gypsum: with gypsum dry 30～50min under 120～150 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum (CaSO40.5H2O);

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio (being mol ratio) of 1: 0. 6～0.8 amount of substance is got urea and formaldehyde, with in urea and the disposable input reaction vessel of formaldehyde (for example: the there-necked flask in laboratory, the industrial reaction vessel of using), begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 10～20min, after reaching cloud point, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, behind reaction 40～60min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, is cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.0～1.5, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material, this low urea formaldehyde resin-gypsum-wilkinite is multiple/effective service life of mixing slow-release material is 2 hours;

G, the low urea formaldehyde resin-gypsum of preparation-bentonite base slow release fertilizer: get nitrogenous for the ammonium sulfate masterbatch of fertilizer total nitrogen 5～25%, get the nitrogenous urea gypsum masterbatch of fertilizer total nitrogen 75～95% that is, mix, make mixture;

Described nitrogenous be the ammonium sulfate masterbatch of fertilizer total nitrogen 5～25%, that is: in the low urea formaldehyde resin-gypsum that makes-bentonite base slow release fertilizer, from the weight (quality) of nitrogen in the ammonium sulfate masterbatch be in the fertilizer total weight nitroxide (quality) 5～25%.

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 5～10 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, making any surface finish, density height, particle diameter is the spheroidal particle of 3～6mm, be dried to water ratio again less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

In the content of the present invention: gypsum described in the steps d can be the plaster of paris, phosphogypsum or desulfurated plaster.

In the content of the present invention: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 20～150% that is described in the step g in the mixture.That is: in the low urea formaldehyde resin-gypsum that makes-bentonite base slow release fertilizer, the weight of phosphorus (quality) be nitrogen weight (quality) 20～150%.

In the content of the present invention: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 20～150%.That is: in the low urea formaldehyde resin-gypsum that makes-bentonite base slow release fertilizer, the weight of potassium (quality) be nitrogen weight (quality) 20～150%.

Compared with prior art, the present invention has following characteristics and beneficial effect:

(1) adopt the present invention, the low urea formaldehyde resin of acquisition has slow-release nitrogen content height, cohesive strength to meet the characteristics that fertilizer requires, and the preparation technology of proposition at normal temperatures, can finish in 40～50 minutes need not heat good energy-conserving effect;

(2) adopt the present invention, urea-formaldehyde resin-gypsum-wilkinite is organic and inorganic compoiste adhering and slow-release material, comprehensive bonding and sustained release performance are better than independent urea-formaldehyde resin and gypsum, and urea-formaldehyde resin itself is good slow-release nitrogen fertilizer, absorption easily is decomposed in soil, do not have residual, gypsum with microsolubility also can discharge calcium and sulfur fertilizer and produce fertilizer efficiency in soil, add the good water conservation of wilkinite and protect the fertilizer efficiency fruit, make urea-formaldehyde resin-gypsum-wilkinite slow-releasing system better effects if, gypsum as sizing agent is semi-hydrated gypsum, has water-absorbent, wilkinite also has good water-absorbent, with both water regain and urea-formaldehyde resins, ammonium sulfate, urea gypsum material moisture coupling can make in the whole preparation process no longer to add water, and does not also need specially to ammonium sulfate, urea gypsum material is dried, thereby the equipment that saves dried material and bring drops into and energy expenditure, is a kind of energy-saving processing technique;

(3) the present invention adopts the granulating integrated technology of preparing of extruding hybrid reaction-vibrosieve-disk to prepare slow release fertilizer.This technology is pointed, respond well to the preparation of urea-formaldehyde resin-gypsum-wilkinite slow release fertilizer.This slow-releasing system very easily forms sticking group, can not be by once extruding or a disk are finished granulation, urea-formaldehyde resin and gypsum are once mixing, must in 2 hours, use, this all requires this slow release fertilizer to need that hybrid reaction-vibrosieve-disk is granulating integrated to be finished, the mixing of storeroom is adopted to stir and can not be reached abundant mixing and reaction, by the mode that extruding mixes, just can make this mixing of materials evenly, sufficient reacting; Mixture is irregular sheet by extruding after the hybrid reaction, need swing crushing, screening after, directly enter the disk granulation, granulation is effective;

(4) the present invention is main raw material with gypsum (plaster of paris, phosphogypsum or desulfurated plaster), low urea formaldehyde resin-the gypsum for preparing-bentonite base slow-release fertilizer, be rich in the SO42-of solubility, can discharge nutrient according to each budding growth demand of crop, can significantly increase grain yield, improve utilization rate of fertilizer, reduced the environmental pollution that agriculture discharging causes, the comprehensive utilization for industrial gypsum simultaneously provides effective way.The agricultural experiment in early stage is the result show, paddy rice, corn can increase production 8%～15% under the equal Fertilization Level, and utilization rate of nitrogen fertilizer can improve 15%～30%.

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.

The phosphogypsum base ammonium sulfate that all uses in the embodiment 1～10, phosphogypsum base urea gypsum, phosphate fertilizer can be any one phosphorus fertilizer; Potash fertilizer can be any one potassium fertilizer.

Embodiment 1:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slow-release rice nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The first step, the preparation of ammonium sulfate: get phosphogypsum, bicarbonate of ammonia is raw material, according to the stoichiometric ratio of CaSO42H2O and NH4HCO3 reaction, with the consumption of CaSO42H2O by weight percentage excessive 5%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of material dry weight 12%, at normal temperatures, behind ball-milling reaction 20 min～60min, namely obtain the ammonium sulfate masterbatch, and nitrogen content is 10.2%, water-content 24.5%.

In second step, the preparation of urea gypsum: get phosphogypsum, urea is raw material, the stoichiometric ratio of reacting according to CaSO42H2O and CO (NH4) 2 is with the consumption of CaSO42H2O by weight percentage excessive 5%; Gypsum, urea are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of material dry weight 12%, at normal temperatures, behind ball-milling reaction 20 min～40min, namely obtain urea gypsum masterbatch, urea nitrogen content is 8.3%, and urea gypsum attitude nitrogen content is 18.8%, water-content 18.3%.

The 3rd step, bentonitic preparation: with the oven dry of natural montmorillonite ore deposit or natural air drying, be crushed to 60～200 orders and namely get wilkinite.

The 4th step, the preparation of semi-hydrated gypsum: phosphogypsum in 150 ℃ of oven dry, is crushed to 60～200 orders, namely obtains semi-hydrated gypsum CaSO40.5H2O.

The 5th step, the preparation of low urea formaldehyde resin: with amount of substance than 1: 0.8 weighing urea and formaldehyde, with load weighted urea and the disposable adding there-necked flask of formaldehyde, begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, the reaction 10～20min, reach cloud point after, transfer its pH to 5.0～6.0 with sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, and after reaction for some time, temperature slowly is down to 40 ℃, transfer its pH value 7.0～8.0 with sodium hydroxide solution, cooling discharge is the oyster white jelly, and water content is about 26%.

In the 6th step, urea-formaldehyde resin-gypsum-wilkinite is multiple/mix the preparation of slow-release material: the urea-formaldehyde resin and the semi-hydrated gypsum that take by weighing mass ratio 1:1.1 mix, prepare urea-formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent.Urea-formaldehyde resin-semi-hydrated gypsum is multiple/mix sizing agent again with wilkinite with the mass ratio of 3:1 be mixed with out urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material.

The 7th step took by weighing the ammonium sulfate of 33.7 weight parts respectively, and the urea gypsum of 66.3 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release rice nitrogenous fertilizer.

Embodiment 2:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slow-release rice composite fertilizer, its concrete preparation process comprises the following steps:

Six steps of the preparation process the first step to the are with embodiment 1.

The 7th step, take by weighing the ammonium sulfate of 10.2 weight parts respectively, 20.0 the urea gypsum of weight part, 57.8 the calcium superphosphate of weight part (phosphorus content 11.3%), the Repone K of 12 weight parts (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release rice composite fertilizer.

Embodiment 3:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slow-release corn nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The 7th step took by weighing the ammonium sulfate of 37.5 weight parts respectively, and the urea gypsum of 62.5 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release corn nitrogenous fertilizer.

Embodiment 4:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slow-release corn composite fertilizer, its concrete preparation process comprises the following steps:

The 7th step, take by weighing the ammonium sulfate of 11.2 weight parts respectively, 18.7 the urea gypsum of weight part, 58.0 the calcium superphosphate of weight part (phosphorus content 11.3%), 12.1 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release corn composite fertilizer.

Embodiment 5:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing soybean nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The 7th step took by weighing the ammonium sulfate of 30.8 weight parts respectively, and the urea gypsum of 69.2 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing soybean nitrogenous fertilizer.

Embodiment 6:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing soybean composite fertilizer, its concrete preparation process comprises the following steps:

The 7th step, take by weighing the ammonium sulfate of 8.2 weight parts respectively, 20.4 the urea gypsum of weight part, 59.1 the calcium superphosphate of weight part (phosphorus content 11.3%), 12.3 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing soybean composite fertilizer.

Embodiment 7:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing wheat nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The 7th step took by weighing the ammonium sulfate of 46.1 weight parts respectively, and the urea gypsum of 53.9 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing wheat nitrogenous fertilizer.

Embodiment 8:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing wheat composite fertilizer, its concrete preparation process comprises the following steps:

The 7th step, take by weighing the ammonium sulfate of 21.5 weight parts respectively, 25.2 the urea gypsum of weight part, 44.6 the calcium superphosphate of weight part (phosphorus content 11.3%), 8.7 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing wheat composite fertilizer.

Embodiment 9:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing rape nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The 7th step took by weighing the ammonium sulfate of 71.8 weight parts respectively, and the urea gypsum of 28.2 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing rape nitrogenous fertilizer.

Embodiment 10:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing rape composite fertilizer, its concrete preparation process comprises the following steps:

The 7th step, take by weighing the ammonium sulfate of 33.5 weight parts respectively, 13.4 the urea gypsum of weight part, 44.2 the calcium superphosphate of weight part (phosphorus content 11.3%), 8.9 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing rape composite fertilizer.

The desulfurized gypsum base ammonium sulfate that all uses in the embodiment 11～20, desulfurized gypsum base urea gypsum, phosphate fertilizer can be any one phosphorus fertilizer; Potash fertilizer can be any one potassium fertilizer.

Embodiment 11:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing Chinese cabbage nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The first step, the preparation of ammonium sulfate: get desulfurated plaster, bicarbonate of ammonia is raw material, according to the stoichiometric ratio of CaSO42H2O and NH4HCO3 reaction, with the consumption of CaSO42H2O by weight percentage excessive 5%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of material dry weight 12%, at normal temperatures, behind ball-milling reaction 20 min～60min, namely obtain the ammonium sulfate masterbatch, and nitrogen content is 11.3%, water-content 23.0%.

In second step, the preparation of urea gypsum: get desulfurated plaster, urea is raw material, the stoichiometric ratio of reacting according to CaSO42H2O and CO (NH4) 2 is with the consumption of CaSO42H2O by weight percentage excessive 5%; Gypsum, urea are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of material dry weight 12%, at normal temperatures, behind ball-milling reaction 20 min～40min, namely obtain urea gypsum masterbatch, urea nitrogen content is 8.7%, and urea gypsum attitude nitrogen content is 19.6%, water-content 17.8%.

The 4th step, the preparation of semi-hydrated gypsum: desulfurated plaster in 150 ℃ of oven dry, is crushed to 60～200 orders, namely obtains semi-hydrated gypsum CaSO40.5H2O.

The 7th step took by weighing the ammonium sulfate of 61.8 weight parts respectively, and the urea gypsum of 38.2 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing Chinese cabbage nitrogenous fertilizer.

Embodiment 12:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing Chinese cabbage composite fertilizer, its concrete preparation process comprises the following steps:

Six steps of the preparation process the first step to the are with embodiment 11.

The 7th step, take by weighing the ammonium sulfate of 33.6 weight parts respectively, 20.8 the urea gypsum of weight part, 26.9 the calcium superphosphate of weight part (phosphorus content 11.3%), 18.7 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing Chinese cabbage composite fertilizer.

Embodiment 13:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing radish nitrogenous fertilizer, its concrete preparation process comprises the following steps:

The 7th step took by weighing the ammonium sulfate of 63.4 weight parts respectively, and the urea gypsum of 36.6 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing radish nitrogenous fertilizer.

Embodiment 14:

The preparation method of a kind of low urea formaldehyde resin-gypsum base slowly-releasing radish composite fertilizer, its concrete preparation process comprises the following steps:

The 7th step, take by weighing the ammonium sulfate of 42.6 weight parts respectively, 24.6 the urea gypsum of weight part, 16.5 the calcium superphosphate of weight part (phosphorus content 11.3%), 16.3 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing radish composite fertilizer.

Embodiment 15:

The 7th step took by weighing the ammonium sulfate of 30.5 weight parts respectively, and the urea gypsum of 69.5 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing soybean nitrogenous fertilizer.

Embodiment 16:

The 7th step, take by weighing the ammonium sulfate of 7.8 weight parts respectively, 20.1 the urea gypsum of weight part, 59.4 the calcium superphosphate of weight part (phosphorus content 11.3%), 12.7 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slowly-releasing soybean composite fertilizer.

Embodiment 17:

The 7th step took by weighing the ammonium sulfate of 33.2 weight parts respectively, and the urea gypsum of 66.8 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release rice nitrogenous fertilizer.

Embodiment 18:

The 7th step, take by weighing the ammonium sulfate of 9.9 weight parts respectively, 19.8 the urea gypsum of weight part, 58.1 the calcium superphosphate of weight part (phosphorus content 11.3%), 12.2 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release rice composite fertilizer.

Embodiment 19:

The 7th step took by weighing the ammonium sulfate of 36.8 weight parts respectively, and the urea gypsum of 63.2 weight parts mixes, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release corn nitrogenous fertilizer.

Embodiment 20:

The 7th step, take by weighing the ammonium sulfate of 10.5 weight parts respectively, 18.3 the urea gypsum of weight part, 58.7 the calcium superphosphate of weight part (phosphorus content 11.3%), 12.5 the Repone K of weight part (potassium content 46.5%), mix, to this mixture add its weight 15% urea-formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; By pushing repeatedly 5～10 times, make its abundant hybrid reaction, again through swing crushing, screening, the disk granulation makes any surface finish, and density height, particle diameter are the spheroidal particle of 3～6mm; Be dried to water ratio less than 2.5%, can make low urea formaldehyde resin-gypsum-bentonite base slow-release corn composite fertilizer.

Embodiment 21:

The preparation method of a kind of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer comprises the following steps:

A, preparation ammonium sulfate masterbatch: get gypsum (CaSO42H2O), bicarbonate of ammonia (NH4HCO3) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 12%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 4 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 13%, at normal temperatures, behind the ball-milling reaction 40min, namely obtain the ammonium sulfate masterbatch;

B, preparation urea gypsum masterbatch: get gypsum (CaSO42H2O), urea (CO (NH4) 2) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 12%; Gypsum, urea are dropped in the ball mill, are 4 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 13%, at normal temperatures, behind the ball-milling reaction 30min, namely obtain urea gypsum masterbatch;

D, preparation semi-hydrated gypsum: with gypsum dry 40min under 140 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum (CaSO40.5H2O);

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio (being mol ratio) of 1: 0. 7 amount of substance is got urea and formaldehyde, with in urea and the disposable input reaction vessel of formaldehyde (for example: the there-necked flask in laboratory, the industrial reaction vessel of using), begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 15min, after reaching cloud point, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, behind the reaction 50min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, be cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.3, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material;

G, the low urea formaldehyde resin-gypsum of preparation-bentonite base slow release fertilizer: get nitrogenous for the ammonium sulfate masterbatch of fertilizer total nitrogen 15%, get the nitrogenous urea gypsum masterbatch of fertilizer total nitrogen 85% that is, mix, make mixture;

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 8 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, making any surface finish, density height, particle diameter is the spheroidal particle of 3～6mm, again drying to water ratio less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

Embodiment 22:

A, preparation ammonium sulfate masterbatch: get gypsum (CaSO42H2O), bicarbonate of ammonia (NH4HCO3) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 5%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 3 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 10%, at normal temperatures, behind the ball-milling reaction 20min, namely obtain the ammonium sulfate masterbatch;

B, preparation urea gypsum masterbatch: get gypsum (CaSO42H2O), urea (CO (NH4) 2) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 5%; Gypsum, urea are dropped in the ball mill, are 3 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 10%, at normal temperatures, behind the ball-milling reaction 20min, namely obtain urea gypsum masterbatch;

D, preparation semi-hydrated gypsum: with gypsum dry 50min under 120 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum (CaSO40.5H2O);

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio (being mol ratio) of 1: 0. 6 amount of substance is got urea and formaldehyde, with in urea and the disposable input reaction vessel of formaldehyde (for example: the there-necked flask in laboratory, the industrial reaction vessel of using), begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 10min, after reaching cloud point, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, behind the reaction 40min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, be cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.0, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material;

G, the low urea formaldehyde resin-gypsum of preparation-bentonite base slow release fertilizer: get nitrogenous for the ammonium sulfate masterbatch of fertilizer total nitrogen 5%, get the nitrogenous urea gypsum masterbatch of fertilizer total nitrogen 95% that is, mix, make mixture;

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 5 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, making any surface finish, density height, particle diameter is the spheroidal particle of 3～6mm, again drying to water ratio less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

Embodiment 23:

A, preparation ammonium sulfate masterbatch: get gypsum (CaSO42H2O), bicarbonate of ammonia (NH4HCO3) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 20%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 15%, at normal temperatures, behind the ball-milling reaction 60min, namely obtain the ammonium sulfate masterbatch;

B, preparation urea gypsum masterbatch: get gypsum (CaSO42H2O), urea (CO (NH4) 2) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 20%; Gypsum, urea are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 15%, at normal temperatures, behind the ball-milling reaction 40min, namely obtain urea gypsum masterbatch;

D, preparation semi-hydrated gypsum: with gypsum dry 50min under 150 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum (CaSO40.5H2O);

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio (being mol ratio) of 1: 0.8 amount of substance is got urea and formaldehyde, with in urea and the disposable input reaction vessel of formaldehyde (for example: the there-necked flask in laboratory, the industrial reaction vessel of using), begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 20min, after reaching cloud point, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, behind the reaction 60min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, is cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.5, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material;

G, the low urea formaldehyde resin-gypsum of preparation-bentonite base slow release fertilizer: get nitrogenous for the ammonium sulfate masterbatch of fertilizer total nitrogen 25%, get the nitrogenous urea gypsum masterbatch of fertilizer total nitrogen 75% that is, mix, make mixture;

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 10 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, making any surface finish, density height, particle diameter is the spheroidal particle of 3～6mm, again drying to water ratio less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

Embodiment 24:

A, preparation ammonium sulfate masterbatch: get gypsum (CaSO42H2O), bicarbonate of ammonia (NH4HCO3) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 9%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 4 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 11%, at normal temperatures, behind the ball-milling reaction 30min, namely obtain the ammonium sulfate masterbatch;

B, preparation urea gypsum masterbatch: get gypsum (CaSO42H2O), urea (CO (NH4) 2) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 9%; Gypsum, urea are dropped in the ball mill, are 3 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 11%, at normal temperatures, behind the ball-milling reaction 30min, namely obtain urea gypsum masterbatch;

D, preparation semi-hydrated gypsum: with gypsum dry 35min under 120～150 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum (CaSO40.5H2O);

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio (being mol ratio) of 1: 0. 6 amount of substance is got urea and formaldehyde, with in urea and the disposable input reaction vessel of formaldehyde (for example: the there-necked flask in laboratory, the industrial reaction vessel of using), begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 12min, after reaching cloud point, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, behind the reaction 45min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, is cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.1, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material;

G, the low urea formaldehyde resin-gypsum of preparation-bentonite base slow release fertilizer: get nitrogenous for the ammonium sulfate masterbatch of fertilizer total nitrogen 10%, get the nitrogenous urea gypsum masterbatch of fertilizer total nitrogen 90% that is, mix, make mixture;

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 7 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, making any surface finish, density height, particle diameter is the spheroidal particle of 3～6mm, again drying to water ratio less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

Embodiment 25:

A, preparation ammonium sulfate masterbatch: get gypsum (CaSO42H2O), bicarbonate of ammonia (NH4HCO3) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 18%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 5 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 14%, at normal temperatures, behind the ball-milling reaction 50min, namely obtain the ammonium sulfate masterbatch;

B, preparation urea gypsum masterbatch: get gypsum (CaSO42H2O), urea (CO (NH4) 2) is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 18%; Gypsum, urea are dropped in the ball mill, are 4 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 14%, at normal temperatures, behind the ball-milling reaction 35min, namely obtain urea gypsum masterbatch;

D, preparation semi-hydrated gypsum: with gypsum dry 40min under 120～150 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum (CaSO40.5H2O);

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio (being mol ratio) of 1: 0.8 amount of substance is got urea and formaldehyde, with in urea and the disposable input reaction vessel of formaldehyde (for example: the there-necked flask in laboratory, the industrial reaction vessel of using), begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 18min, after reaching cloud point, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, because this reaction is thermopositive reaction, self heat release is enough to provide polycondensation temperature required, behind the reaction 55min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, is cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.4, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material;

G, the low urea formaldehyde resin-gypsum of preparation-bentonite base slow release fertilizer: get nitrogenous for the ammonium sulfate masterbatch of fertilizer total nitrogen 20%, get the nitrogenous urea gypsum masterbatch of fertilizer total nitrogen 80% that is, mix, make mixture;

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 9 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, making any surface finish, density height, particle diameter is the spheroidal particle of 3～6mm, again drying to water ratio less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

In above-described embodiment 21-25: gypsum described in the steps d can be the plaster of paris, phosphogypsum or desulfurated plaster.

In above-described embodiment 21-25: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 20～150% that is described in the step g in the mixture.That is: in the low urea formaldehyde resin-gypsum that makes-bentonite base slow release fertilizer, the weight of phosphorus (quality) be nitrogen weight (quality) 20～150%.

In above-described embodiment 21-25: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 20% that is described in the step g in the mixture, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 150% that is described in the step g in the mixture, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 85% that is described in the step g in the mixture, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 50% that is described in the step g in the mixture, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 120% that is described in the step g in the mixture, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 20～150%.That is: in the low urea formaldehyde resin-gypsum that makes-bentonite base slow release fertilizer, the weight of potassium (quality) be nitrogen weight (quality) 20～150%.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 20%, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 150%, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 80%, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 50%, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 100%, other is with corresponding embodiment.

In above-described embodiment 21-25: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 120%, other is with corresponding embodiment.

In above-described embodiment: each raw material that adopts is the commercially available prod.

In above-described embodiment: in the percentage that adopts, do not indicate especially, be weight (quality) percentage; Described weight (quality) part can all be gram or kilogram.

In above-described embodiment: the processing parameter in each step and each amounts of components numerical value etc. are scope, and any point is all applicable.

The not concrete same prior art of narrating of technology contents in content of the present invention and above-described embodiment.

The invention is not restricted to above-described embodiment, content of the present invention is described all can implement and have described good result.

Claims

1. the preparation method of low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer is characterized in that comprising the following steps:

A, preparation ammonium sulfate masterbatch: get gypsum, bicarbonate of ammonia is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and bicarbonate of ammonia, with the consumption of gypsum by weight percentage excessive 5%～20%; Gypsum, bicarbonate of ammonia are dropped in the ball mill, are 3～5 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 10～15%, at normal temperatures, behind ball-milling reaction 20～60min, namely obtain the ammonium sulfate masterbatch;

B, preparation urea gypsum masterbatch: get gypsum, urea is raw material, carry out the stoichiometric ratio of chemical reaction according to gypsum and urea, with the consumption of gypsum by weight percentage excessive 5%～20%; Gypsum, urea are dropped in the ball mill, are 3～5 input abrading-balls by ball material weight ratio, add the water of raw material gross weight 10～15%, at normal temperatures, behind ball-milling reaction 20～40min, namely obtain urea gypsum masterbatch;

D, preparation semi-hydrated gypsum: with gypsum dry 30～50min under 120～150 ℃ of temperature, be crushed to 60～200 orders again, namely obtain semi-hydrated gypsum;

E, the low urea formaldehyde resin of preparation: in urea: formaldehyde is that the ratio of 1: 0. 6～0.8 amount of substance is got urea and formaldehyde, in urea and the disposable input reaction vessel of formaldehyde, begin heating and stirring, when rising to 25 ℃, temperature stops heating, after treating that urea dissolves fully, with hydrochloric acid or sulfuric acid adjust pH to 4.0～5.0, reaction 10～20min, reach cloud point after, transfer pH to 5.0～6.0 with aqueous sodium hydroxide solution, behind reaction 40～60min, temperature slowly is down to 40 ℃, transfers pH to 7.0～8.0 with aqueous sodium hydroxide solution, is cooled to room temperature, obtain the oyster white jelly, namely make low urea formaldehyde resin, water content is about 26%;

F, the low urea formaldehyde resin-gypsum of preparation-wilkinite be multiple/mix slow-release material: and by low urea formaldehyde resin: semi-hydrated gypsum is the part by weight of 1:1.0～1.5, to hang down urea formaldehyde resin and semi-hydrated gypsum mixes, namely make low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent; Again by low urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent: wilkinite is the part by weight of 3:1, to hang down urea formaldehyde resin-semi-hydrated gypsum multiple/mix sizing agent and wilkinite mixes, namely make low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material;

To mixture add mixture weight 15% low urea formaldehyde resin-gypsum-wilkinite multiple/mix slow-release material; Push repeatedly 5～10 times by extrusion machine, make its abundant hybrid reaction, again through swing crushing, screening, disk granulation, make the spheroidal particle that particle diameter is 3～6mm, again drying to water ratio less than 2.5%, namely make low urea formaldehyde resin-gypsum-bentonite base slow release fertilizer.

2. by the preparation method of the described low urea formaldehyde resin-gypsum of claim 1-bentonite base slow release fertilizer, it is characterized in that: gypsum described in the steps d is the plaster of paris, phosphogypsum or desulfurated plaster.

3. by the preparation method of claim 1 or 2 described low urea formaldehyde resin-gypsum-bentonite base slow release fertilizers, it is characterized in that: can also be added with the phosphorous phosphorus fertilizer of fertilizer total nitrogen 20～150% that is described in the step g in the mixture.

4. by the preparation method of claim 1 or 2 described low urea formaldehyde resin-gypsum-bentonite base slow release fertilizers, it is characterized in that: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 20～150%.

5. by the preparation method of the described low urea formaldehyde resin-gypsum of claim 3-bentonite base slow release fertilizer, it is characterized in that: can also be added with in the mixture described in the step g and contain the potassium fertilizer that potassium is fertilizer total nitrogen 20～150%.