CN1198427A

CN1198427A - Nitrogenous phosphate potash long-effect compound fertilizer and productive method thereof

Info

Publication number: CN1198427A
Application number: CN97103575A
Authority: CN
Inventors: 吕庆淮
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-05-01
Filing date: 1997-05-01
Publication date: 1998-11-11

Abstract

The present invention belongs to an agricultural fertilizer, relates to a new-type long-acting composite fertilizer and its production method. Said invention uses the phosphogypsum which possesses the function of amending soil and the humic acid contained in peat which is a good soil improving agent and plant growth stimulant as main raw materials, and mixes them with urea, ammonium phosphate and potassium sulfate, and adopts a composite organic material coating process to produce said invented long-acting composite fertilizer. Said invented composite fertilizer is applicable to crops of maize, wheat and rice, etc., and can improve soil structure, raise yield by above 10%, and its production process is simple, cost is low, so that it is easy to popularize in agriculture.

Description

Nitrogen-phosphorus-potassium long-acting compound fertilizer and production method thereof

At present, the phenomenon of low fertilizer utilization rate in China generally exists. According to the reports of the literature, the utilization rate of the nitrogen fertilizer is about 35-60%, the utilization rate of the phosphate fertilizer is about 10-15%, and the utilization rate of the potassium fertilizer is about 30-60%, namely, about half of nitrogen, phosphorus and potassium applied to the field are absorbed and utilized by crops in the season, even most of the nitrogen, phosphorus and potassium are not absorbed and utilized by the crops in the season. One part of the fertilizer is converted into slow-acting nutrients in soil, and the other part of the fertilizer is wasted due to the loss of white water.

The reasons for the low utilization rate of the fertilizer are manifold, and the reasons for the low utilization rate of various nutrient elements are different. Nitrogen fertilizers are generally thought to result from denitrification of nitrates and loss of ammonia by volatilization. Urea is mainly caused by the decomposition loss of ammonium carbonate generated by the rapid hydrolysis of soil urease. In addition, residual nitrogen that may be leached by rain into deep soil is also largely ineffective.

The release rate of the nutrient elements of the fertilizer is asynchronous with the whole growth period of crops, and is also one of the reasons for low utilization rate of the effective ingredients.

Phosphate fertilizers do not volatilize and have less drenching, but they have poor mobility in the soil. Meanwhile, Ca is easy to be contained in the soil²⁺，Mg²⁺The plasma is fixed, so the utilization rate of the phosphate fertilizer is lower.

The reason for the low utilization of potassium fertilizer is similar to that of nitrogen fertilizer. The main reason for the low utilization rate of potash fertilizer is that potassium ions can enter into the crystal lattice of clay minerals to be fixed under the alternation of dry and wet in soil, and can also be determined by chemical reaction and biological action.

In addition, the inconsistent proportion of nitrogen, phosphorus and potassium, the lack of trace elements and the like are also one of the reasons for poor growth of crops and low utilization rate of chemical fertilizers.

At present, due to the fact that a large amount of chemical fertilizers are used, the using amount of organic fertilizers is relatively reduced, soil nutrient structure proportion is disordered, soil is hardened, particularly in northern areas of China, the water level of the ground surface is reduced due to long-term drought, the soil desertification speed is increased, a serious fertilizer leakage phenomenon is caused, and the low utilization rate of the chemical fertilizers is also one of main reasons.

The quick-dissolving and quick-acting fertilizer such as ammonium bicarbonate, ammonium phosphate and urea which is commonly used by farmers is applied to the ground and watered or can be absorbed after being dissolved in rain, and if the fertilizer is not watered or does not rain or is dry, the fertilizer cannot generate fertilizer effect, but the fertilizer can harm crops, even burn and kill seedlings. For a long time, the fertilizer application of farmers is basically high-nitrogen low-phosphorus potassium, and the yield can be increased by applying a large amount of nitrogen fertilizer to the ground all the year round. However, the phosphorus and potassium elements in the soil are deficient. Causing the taste quality of the fruits of the crops to be reduced year by year. For example: watermelon is large but not sweet, snow pear is large, meat bran lacks sweet taste, and the like. It can be said that the quality of crops is reduced to some extent. This is not caused by the deterioration of crop varieties, the main reason for which is due to high nitrogen, low phosphorus and potassium.

Soil fertility is a major factor affecting the sustainable development of agricultural production. To keep the agricultural production stable and continuous, the soil nutrient content is increased, the nutrient composition is coordinated, the soil nutrient condition is improved, and the soil fertility is continuously improved.

Currently, the world chemical fertilizer production has entered a new stage, and the high-efficiency multi-element compound fertilizer is replacing the past single low-concentration chemical fertilizer variety. Meanwhile, many countries have applied coating, bio-inhibition technologies to the fertilizer industry to produce, for example, coated, bio-inhibitor fertilizers. However, these fertilizers have complicated processes, high costs and poor environmental benefits, and especially, the performance of the single-element fertilizersafter secondary processing is improved, but the cost is increased, which increases the burden of farmers.

In recent years, humic acid has been applied to the fertilizer industry in China to produce compound fertilizer products containing humic acid and fulvic acid. Humic acid is a complex mixture of substances with similar structural properties, and is an alkali extract of turf, lignite or weathered coal. Since it is a hydrocolloid which carries acidic groups capable of exchange binding with metal ions, and also redox groups (and perhaps some groups not known) it is a multifunctional mixture. Humic acid has long been proven as a plant production regulator, and can also inhibit stomatal aperture and reduce transpiration of plants. Thus, resistant to drought or wilt.

Humic acid is an excellent soil conditioner and plant production stimulant. Has strong adsorption effect on nutrients and moisture, and can form chelate with various elements such as aluminum, magnesium, calcium and the like in soil, thereby preventing the elements such as aluminum, magnesium, iron, calcium and the like in the soil from fixing phosphorus, and greatly improving the utilization rate of the phosphorus.

Humic acid can also release various elements constantly through base exchange, decomposition and as a chelating agent.

Humic acid fertilizer is a kind of fertilizer developed in recent years in China. CN1025430C and CN 1030655C. Among such fertilizers are solid fertilizers. Some are liquid fertilizers. From the viewpoint of convenience in storage and transportation and use, farmers prefer to use solid fertilizers. In particular to a high-efficiency solid compound fertilizer. The nutrient proportion of nitrogen, phosphorus and potassium in the long-acting compound fertilizer produced at present is not harmonious enough. The nitrogen and phosphorus content is much higher thanthat of potassium, so that the proportion of nitrogen, phosphorus and potassium in the soil cannot be effectively adjusted, the growth and development of some crops are not facilitated, and meanwhile, the soil nutrient is also disordered. Is not beneficial to the high quality and the high yield of crops.

Although humic acid has strong adsorption effect on nutrients and moisture, the humic acid has different using concentrations and different sources and has different effects. Thus, remaining mature results in partial loss and waste of fertilizer nutrients.

Natural gypsum can be used as a soil conditioner. It is agreed that Ca is present in calcium sulfate²⁺And 2Na⁺Exchange, thereby improving the permeability of the clay. Phosphogypsum can also be used as a soil conditioner without purification. The use of phosphogypsum as a soil conditioner has been successful in both the united states and australia.

The composition of the phosphogypsum is different due to different wet-process phosphoric acid process flows and raw material ores in different areas. The composition of phosphogypsum (filter cake) obtained by using 73-75BPL Morocco mine as a raw material and adopting a semi-hydrate process, a dihydrate process and a semi-hydrate-dihydrate process is as follows in percentage by weight (dry basis): p₂O₅＜1.4％，CaO 32％-37％，SO₄ ^2-52.8％-60.1％，F0.5％-1.5％，SiO₂0.4％-0.7％，Fe₂O₃＜0.1％，Al₂O₃Less than 0.1 percent and less than 0.1 percent of MgO, and in addition, trace elements of Cd, Cu, Zn, Pb, Cr and V can also be transferred from phosphorite to phosphogypsum, wherein the transfer amount of the trace elements is as follows by weight percent: 20 percent of Cd, 64 percent to 100 percent of Cu, 20 percent to 49 percent of Zn, 100 percent of Pb, 3 percent to 26 percent of Cr and 1 percent to 100 percent of V.

The amount of the byproduct phosphogypsum in the wet-process phosphoric acid is different according to different raw material ores and different process flows. General production of 1tP₂O₅About 4-6t of phosphogypsum is a byproduct. In China, the byproduct phosphogypsum is not utilized in a large amount, so that a large amount of overstocks exist in a plurality of phosphoric acid plants and ammonium phosphate plants. Even brings great trouble to manufacturers. Because it takes up a large area of space and cannot be utilized. Is disadvantageous in terms of environmental protection and economic efficiency. The development and utilization of the phosphogypsum are a matter benefiting the nation and the people.

Urea and formaldehyde are subjected to polycondensation reaction to prepare urea formaldehyde, and the reaction equation is as follows:

the product urea formaldehyde (resin) molecule is a net structure, and due to the steric hindrance effect in the molecule, the condensation reaction always contains part of unreacted hydroxyformaldehyde (in the industrial production, when the PH is 7-8, the reaction end point is determined by that the free aldehyde in the reactant reaches 6-8%), so that the product urea formaldehyde (resin) has larger water absorption. Can be made into aqueous solution and alcoholic solution. Urea-formaldehyde resins are hard and brittle and are usually modified by the addition of cellulose, mica, metal powders, and the like. Urea-formaldehyde (resin) can be used as slow-release fertilizerThe use of such catalysts has long been known.

The product of the urea-formaldehyde condensation reaction is dehydrated in vacuum to prepare the urea-formaldehyde resin adhesive, and the talcum powder and the industrial flour are added for modification. Talcum powder and industrial flour areused as a carrier for fertilizer as a filler.

The oxidized starch is prepared from corn starch by using chlorine (Cl) in sodium hypochlorite⁺) Is reduced to (Cl)^-) The oxygen (O) of the new ecology is released, while nascent oxygen renders primary alcohol groups (-CH) in the starch molecule₂OH) is first oxidized toAldehyde group (-CHO), and finally to carboxyl group (-COOH), i.e.

Therefore, the oxidized starch is modified starch mainly containing carboxyl or aldehyde molecular structures.

The urea-formaldehyde resin contains a large amount of dihydroxymethylurea and also contains a B-stage resin which is formed by knitting and has a chain with methine bonds. The B-stage resin becomes a three-way cross-linked urea-formaldehyde resin quickly under the action of carboxyl (-COOH) in the starch adhesive. On the other hand, the carboxyl group in the starch binder also easily promotes the reaction of hydroxyl group (-OH) in the urea resin. Therefore, the drying performance of the adhesive is better than that of the common starch adhesive.

The oxidized starch has swelling property under the action of soil moisture. Therefore, it has an adsorption capacity for urea nitrogen. The modified urea-formaldehyde resin adhesive and the oxidized starch adhesive are mixed to form a novel composite material and become a novel urea nitrogen adsorbent. The compound fertilizer made up by using it as adhesive and carrier is easy to swell by using oxidized starch under the action of soil moisture so as to raise the adsorption capacity of urea nitrogen.

Polysaccharide natural polymers such as starch and cellulose, which are readily biodegraded to form CO in an oxygen-free or oxygen-free process under humid conditions₂And H₂And O. Most microbially degraded polymers are solubilized by hydrolysis. The starch and protein are secreted by fungi or bacteriaUnder the action of enzyme, the material is firstly hydrolyzed and then oxidatively degraded. Therefore, the oxidized starch and the industrial flour not only do not affect the environment, but also have the function of improving the soil. Along with the gradual degradation of the oxidized starch and the industrial flour, the adsorbed and coated nutrients are gradually released, so that the fertilizer effect is delayed.

The invention aims to: the fertilizer has the advantages of utilizing natural resources, reasonably adjusting the nutrient content in fertilizer application, improving the yield and quality of crops, reducing the production cost, protecting the environment, improving the soil structure, improving the soil fertility and improving the economic benefit and the social benefit.

The compound fertilizer is based on the comprehensive requirement of wheat, corn, rice and other crops on nitrogen, phosphorus, potassium and trace elements. On the basis of preliminary investigation and understanding of soil structure and fertility of two provinces and cities of Shandong and Henan, from the strategic heights of developing agriculture, protecting environment, improving soil structure, improving soil fertility, improving crop yield and quality, reducing cost and improving economic and social benefits in China, peat with abundant domestic resources and phosphogypsum which is not developed and utilized in large quantities are utilized, a composite organic material wrapping process is adopted, inorganic materials, peat and phosphogypsum are mixed and granulated, and different granulation technologies and different fertilization methods are adopted to develop the nitrogen-phosphorus-potassium long-acting compound fertilizer. Compared with long-acting fertilizer and multi-element fertilizer at home and abroad, the fertilizer not only reasonably utilizes natural resources, has low production cost and simple production process, but also has good protection and promotion effects on soil, crops and water to calculate ecological environment.

The purpose of the invention is realized by the following technical scheme: 20% of urea, 19% of potassium sulfate, 16% of diammonium phosphate or 23% of urea, 13% of monoammonium phosphate, 19% of potassium sulfate, 25% of peat, 8% of phosphogypsum and 4% of talc are weighed according to the weight percentage, after the raw materials are crushed, the peat granularity is not more than 40 meshes, the moisture content is less than 10%, the phosphogypsum granularity is less than 100 meshes, the free moisture content is less than 5%, the talcum powder granularity is less than 100 meshes, and the water content is less than 3%. The granularity of each component of the inorganic fertilizer is not more than 60 meshes, wherein the content and the water content of each component are required according to the national standard.

Weighing 85% of oxidized starch glue, 10% of urea-formaldehyde resin glue and 5% of industrial flour in percentage by weight, mixing and stirring uniformly for about 30 minutes to prepare the composite organic (adhesive) material.

Mixing inorganic fertilizer with peat, adding 8 wt% of composite organic (adhesive) material, stirring and mixing uniformly, adding phosphogypsum and talcum powder, mixing and stirring uniformly, feeding into a roller granulator for granulation, producing granules of 2-3mm and 4-6mm as required, feeding into a dryer for drying at a drying temperature of 120-130 ℃, gradually cooling at normal temperature after discharging, feeding the cooled fertilizer into a rotary sieve for sieving, and finally metering and packaging the sieved finished product according to the granularity.

The product has the following characteristics:

total nutrient (N, P)₂O₅，K₂O) content>30%

The free water content is less than or equal to 6 percent

The particle size is 2-3mm, 4-6mm

The main application and the use method are as follows:

the compound fertilizer of the invention is a long-acting compound fertilizer for crops, and has good yield increasing effect on crops such as wheat, corn, rice and the like. Meanwhile, the fertilizer has the characteristics of improving the quality of crops, improving the soil structure, improving the soil fertility, resisting drought and delaying the fertilizer efficiency. The field test shows that: the yield of wheat per mu is increased by 10.8-16.7%, the yield of corn per mu is increased by 11.4-18.6%, and the yield of rice per mu is increased by 13.5-21.3%.

The using method comprises the following steps:

wheat is used as base fertilizer, when the soil is turned over before sowing, 60 jin of fertilizer with the granularity of 2-3mm and 4-6mm is applied to each mu, and when the soil is sowed, 20 jin of fertilizer with the granularity of 2-3mm is applied to the soil along with the seeds to be used as seed fertilizer.

When the corn is turned over, 50 jin of large and small grains are applied to each mu of corn through fertilizer, and 30 jin of fertilizer with the grain size of 2-3mm is applied to each mu of corn during seed distribution, and the corn is used as seed fertilizer along with seeds.

Rice is used as base fertilizer, before field soaking, fertilizer with the thickness of 4-6mm is 80 jin per mu, thefertilizer with the thickness of 2-3mm is 60 jin per mu, and a supporting plate is raked and sealed.

Claims

1. A long-acting composite N-P-K fertilizer is prepared from inorganic fertilizer (55 wt.%), peat (25), ardealite (8), talc powder (4) and organic composite material (8). The 55 wt% inorganic fertilizer consists of 20 wt% urea, 19 wt% potassium sulfate, 16 wt% diammonium phosphate or 23 wt% urea, 19 wt% potassium sulfate, 13 wt% monoammonium phosphate; the composite organic material consists of oxidized starch glue 85 wt%, urea-formaldehyde resin glue 10 wt% and industrial flour 5 wt%.

2. The production method of the long-acting compound fertilizer of nitrogen, phosphorus and potassium according to claim 1 is that inorganic fertilizer, peat, phosphogypsum and talc are crushed, the inorganic fertilizer, peat and composite organic material are mixed uniformly, then talcum powder and phosphogypsum are added, and the product is obtained by stirring, mixing uniformly, granulating and drying.

3. The production method according to claim 2, wherein the content of humic acid in the peat is not less than 15% by weight.

4. The production method according to claim 2, characterized in that the particle size of the peat is not larger than 40 mesh.

5. The production method according to claim 2, characterized in that the particle size of the inorganic fertilizer is not more than 60 mesh.

6. The production process of claim 2, wherein the particle size of the phosphogypsum and the talc powder is less than 100 meshes.

7. The long-acting compound fertilizer according to claims 1, 2, 3, 4, 5 and 6, characterized in that the finished product has the following characteristics:

total nutrient (N, P)₂O₅，K₂O) content>30%

The granularity is 2-3mm and 4-6 mm.

The free moisture content is less than or equal to 6 percent.