CN1161317A - Method for prodn. of multi-nutrient slow releasing coated urea - Google Patents

Abstract

A slow release nitrogen fertilizer is made by encapsulating sulfur powder, magnesium oxide, zinc sulfate, cupper sulfate, manganese sulfate, ferrous sulfate, borax and ammonium molyndate (or sodium molybdate) or a part of these nutritive substances on the surface of urea. It is low in investment and cost. The utilization ratio of nitrogen is enhanced.

Description

A kind of method of producing many nutrition of slow coated carbamide

What patent of the present invention related to is a kind of production method that contains the slow urea of middle amount, micro-plant nutrient.

After urea is manured into soil, very fast dissolving, and in soil, be converted into ammonia-state nitrogen and nitric nitrogen under the effect of urease.Its fertilizer efficiency is short, and some nitrogen is with rainwater or irrigation water leaching loss or loss, and some ammonia-state nitrogen vapors away.Therefore, the nitrogen in the urea can not all be absorbed by crop, and its this season is had only about 40% by the utilization ratio of crop, has nitrogen loss over half to fall.Staple crop sees Table 1 to the utilization ratio of nitrogen in the urea.So the utilization ratio that improves nitrogen in the urea is the important topic that faces both at home and abroad.For improving the utilization ratio of nitrogen in the urea, normally urea further is processed into slow-release fertilizer, the nitrogen in the urea is slowly discharged in the back that is manured into soil, to satisfy the needs of crop growth period, reduce the loss of nitrogen in the urea, improve the utilization ratio of nitrogen.External method of producing slow urea mainly contains three kinds: (1) adopts chemical synthesis, and it is slow or decompose slow compound to make urea be converted into dissolving, as urine formaldehyde; (2) in urea, add urease inhibitors, to slow down the speed that urea decomposes in soil; (3) slow down its stripping at urea external parcel one deck sustained release film, as the bag Thio Urea.Coated carbamide wherein, particularly wrapping Thio Urea is the slow urea of external turnout maximum, and this mainly is because urea external parcel sulphur not only can make the urea slow, and simultaneously, sulphur also is the fourth-largest nutritive element that crop needs.Produce 6 tons of wheats as per hectare, to the demand of N, P, K, S be respectively 120,25,80,25kg; Per hectare is produced 7 tons of paddy rice, to the demand of N, P, K, S be respectively 150,25,17,20kg.Along with the continuous increase of high concentration fertilizer amount of application, the calcium superphosphate amount of application of sulfur-bearing reduces relatively, and the raising of crop yield, and a lack of sulfur area all constantly enlarges both at home and abroad.No matter all there is the report of a large amount of as lack of sulfur in the south or the north in China, execute behind the sulphur that wheat on average increases production 15%, paddy rice 16%, coleseed 19%.The bag Thio Urea not only can improve the utilization ratio 5%～10% of nitrogen, and can suppress the generation of disease and pest.

Table 1 staple crop is to the utilization ratio crop nitrogenous fertilizer test number test point utilization rate of nitrogen fertilizer/% of nitrogen in the urea

Mean value luffing paddy rice urea 125 Ningxia, Henan, Jiangsu, Zhejiang 38 22～62

Jiangxi, Anhui, Shanghai, wheat urea 58 Gansu, Guangxi, Ningxia, Henan, Beijing 41 9～72

Shandong, Jiangsu, Zhejiang, Shanghai, Sichuan

Annotate: data source " phosphate fertilizer and multiple fertilizer " the 4th phase in 1996.

At present, external method of producing the bag Thio Urea mainly contains two kinds: the one, and fusion sulphur coated urea; The 2nd, SULPHUR POWDER is added in the fusing urea solution, make sulfur-coated urea.The former investment is bigger, and production cost is higher, and latter's slow is relatively poor.Develop the purpose of this patent of invention, be to find a kind of different, be fit to the method for the production slow urea of China's national situation, to improve the utilization ratio of nitrogen, for agricultural provides concentrated fertilizer with state outsourcing Thio Urea production technique.Simultaneously, China the big area a lack of sulfur occurred and has lacked micro-phenomenon, according to soil regime and crop needs, in the adding, trace element, make many nutrition coated carbamide, both solved a lack of sulfur problem and also solved the difficult problem of all executing of trace element fertilizer, because the fertilising inequality also can cause damage to crop, also solve the agglomeration problems during urea is deposited, helped mechanized application.

Many nutrition of slow coating urea production process is as follows:

Raw material: agricultural urea; SULPHUR POWDER; 98% sulfuric acid; Water glass; Magnesium oxide; Zinc sulfate; Copper sulfate; Manganous sulfate; Ferrous sulfate; Borax; Ammonium molybdate or Sodium orthomolybdate.

Technological process is: (1) raw material is handled: urea need sieve if any caking, and the urea that will lump sifts out; Sulphur need be crushed to 20～500 orders; Magnesium oxide, zinc sulfate, copper sulfate, manganous sulfate, ferrous sulfate, borax, ammonium molybdate or Sodium orthomolybdate need be crushed to 50～300 orders.(2) binder making: the water glass of 1～5 part of weight is dissolved in the water of 10 parts of weight, adds the sulfuric acid of 1～10 part of weight behind the uniform mixing, uniform mixing is cooled to below 50 ℃ standby again.(3) production of many nutrition of slow coated carbamide: with the raw material urea of handling well, its consumption is for being 20%～90% of benchmark with the product weight, add in the coating machine, with powder raw materials such as SULPHUR POWDER, magnesium oxide, zinc sulfate, copper sulfate, manganous sulfate, ferrous sulfate, borax, ammonium molybdate or Sodium orthomolybdates, its consumption mixes in proportion for being 80%～10% of benchmark with the product weight.On the urea in coating machine, the binding agent that the limit spray is made by water glass and sulfuric acid, its consumption is for being 1%～20% of benchmark with the product weight, the limit adds the above-mentioned powder raw material that mixes.Utilize the cohesive action of binding agent, make powder raw material be wrapped in urea surface equably, form the film of one deck densification, the work in-process drying, many nutrition of slow coated carbamide gets product after the cooling.

Example: take by weighing the 0.5kg water glass, be dissolved in the 3kg water, after mixing, add 1.5kg sulfuric acid while stirring.Sulfuric acid added the back restir 5 minutes, was cooled to and was the binding agent for preparing below 50 ℃.Take by weighing 65kg urea, 15kg SULPHUR POWDER, 10kg magnesium oxide, 0.25kg ferrous sulfate, 0.25kg manganous sulfate, 0.1kg copper sulfate, 0.12kg zinc sulfate, 0.05kg borax, 0.001kg ammonium molybdate.The SULPHUR POWDER, magnesium oxide, ferrous sulfate, manganous sulfate, copper sulfate, zinc sulfate, borax and the ammonium molybdate that weigh up are mixed.Urea is added in the packing machine, the limit sprays into the binding agent for preparing, and the limit adds the above-mentioned powder raw material that mixes, after raw material and binding agent add, promptly make work in-process, the work in-process drying promptly gets many nutrition of 100kg slow coating urea product after solidifying, cooling off.Product contains 29.9%N, 15%S, 6%Mg, 0.05%Fe, 0.065%Mn, 0.025%Cu, 0.025%Zn, 0.01%B, 0.002%Mo.

Succeeding in developing of many nutrition of slow coated carbamide, its Technology, product performance have been compared certain advantage with the farmingization effect with external existing bag Thio Urea product with technology.This mainly shows: (1) select for use a kind of composite binding agent with SULPHUR POWDER and in, trace element etc. is wrapped in urea surface, and this binding agent is a kind of soil conditioner, it has saved molten sulphur equipment, thereby reduced investment, cost are low.The farmingization test shows, than the contrast volume increase 9.5% that waits nutrient; (2) compare with state outsourcing Thio Urea, in having added, trace element,, make itself and sulphur be wrapped in urea surface together as magnesium, boron, copper, zinc, iron, molybdenum, manganese etc.According to India's experimental study, trace element is wrapped in urea surface, is difficult for by soil fixing, and its utilization ratio can improve 50%; (3) solved the agglomeration problems of urea.External for preventing urea from caking, add anti-hard caking agent specially.

Many nutrition of slow coated carbamide is processed into its all or part of urea product in the factory that makes urea that present technique is suitable for various scales.The production and the urea production of many nutrition of slow coated carbamide are relatively independent, as increasing 300m ²About factory building and relevant devices, can build up 10,000 tons of/year many nutrition of slow coating urea plants, neither need to do any change to original urea plant, do not influence the production that the crude urine white, quiet clothes are put yet.

Claims (4)

1. the production method of many nutrition of slow coated carbamide, it is characterized in that adopting a kind of composite binding agent, powdered SULPHUR POWDER, magnesium oxide, zinc sulfate, copper sulfate, manganous sulfate, ferrous sulfate, borax, ammonium molybdate or Sodium orthomolybdate are wrapped in urea surface, realize the slow of urea, and measure and micronutrient element for crop provides middle.

2. by the described method of claim 1, its SULPHUR POWDER need be crushed between 20～500 orders, and magnesium oxide, zinc sulfate, copper sulfate, manganous sulfate, ferrous sulfate, borax, ammonium molybdate or Sodium orthomolybdate need be crushed between 50～300 orders.

3. by the described method of claim 1, its amount of urea is for being 20%～90% of benchmark with the product weight; The consumption of SULPHUR POWDER, magnesium oxide, zinc sulfate, copper sulfate, manganous sulfate, ferrous sulfate, borax and ammonium molybdate or Sodium orthomolybdate is for being 80%～10% of benchmark with the product weight.

4. by the described method of claim 1, its used caking agent is by the water of the water glass of 1～5 part of weight, 10 parts of weight and composite the forming of sulfuric acid of 1～10 part of weight, and the binding agent consumption is for being 1%～20% of benchmark with the product weight.