Everyone said their plant compound fertilizer production process is which category ah!

Introduction of the main technology and production methods of compound fertilizer

A comprehensive granular compound fertilizer production methods are mainly the following:

1. Slurry method

Phosphoric acid, ammonia as raw materials, the use of neutralizer, tubular reactor will be neutralized slurry in the ammonia granulators for coating granulation in the process of production to add part of the nitrogen and potash, as well as other substances, and then by drying, screening, cooling and get NPK compound fertilizer products, which is often used by major fertilizer companies and plants at home and abroad for large-scale production. Then after drying, sieving, cooling and get NPK compound fertilizer products, which is a large-scale production of major fertilizer companies and factories at home and abroad often use the production method.

Phosphoric acid can be produced by sulfuric acid decomposition of phosphate ore, and when possible, can also be directly purchased commercial phosphoric acid, in order to reduce investment and simplify the production process. The advantage of this method is that it can produce both ammonium phosphate and NPK fertilizer, and also make full use of the acid and ammonia neutralization heat to evaporate the material water, reduce the water content of granulation and drying load, and reduce energy consumption.

As a result of usually need to support the construction of phosphoric acid plant and sulfuric acid plant, the construction is not only a large investment, long cycle, and involves the supply of phosphorus, sulfur resources and many environmental protection issues (such as phosphogypsum, fluorine, acid foam, acid sludge, etc.), is generally more suitable for processing bases in the phosphorus ore and the larger-scale production, the product product of a small number of cases. If the purchased commodity phosphoric acid as raw materials, the current stable source and transportation problems and price factors have to be considered, in recent years, due to China's phosphoric acid industry technology and equipment level of the improvement of wet phosphoric acid as a commodity into the market has good conditions, in the resources and conditions of the establishment of the phosphoric acid base in the region to meet the need for the development of other regions of the commodity phosphoric acid phosphate fertilizers of the need for the development of high-concentration is the formation of a new The market demand will certainly promote the development of this industry and solve the problem of raw material phosphoric acid demand in many regions. Have the production technology of foreign companies are mainly Norway's norskhydro, Spain incro, espindsea, France's AZF, KT, the United States avy / TVA and so on.

The main domestic manufacturers are: China-Arab Fertilizer Co., Ltd, Jiangxi Guixi Fertilizer Plant, Yunnan Yunfeng Chemical Company, Nanjing Nanhua Phosphorus Fertilizer Plant, Dalian Chemical Plant, Jinchang Chemical Company, Guangxi Luzhai Phosphorus Fertilizer Plant and so on. Have similar to the production technology of the domestic enterprises are mainly Shandong's Hongri Group, Sichuan Chengdu University of Science and Technology, Shanghai Research Institute of Chemical Technology.

2. Solid agglomeration method

To monomer basic fertilizers such as: urea, ammonium nitrate, ammonium chloride, ammonium sulphate, ammonium phosphate monoammonium phosphate, diammonium phosphate, heavy calcium, calcium), potassium chloride (potassium sulfate) and so on as raw materials, crushed to a certain degree of fineness, the material is in the rolling bed of the rotary drum granulator (or the garden disc granulator) through humidification, heating for agglomeration granulation, in the process of granulation, the conditions can also be in the rotary drum granulator (or garden disc granulator). In the process of granulation, conditions can also be added to a small amount of phosphoric acid and ammonia in the drum granulator to improve the conditions of granulation. Granulated material by drying, sieving, cooling that is to get NPK compound fertilizer products, which is also one of the international widely used method, the early United States and India, Japan, Thailand and other Southeast Asian countries are using this method of production.

The method of raw materials from a wide range of easy to get, the processing process is relatively simple, less investment, low production costs, fast, production flexibility, product grade adjustment is simple and easy, more versatile, the raw materials used are solid, the dependence on raw materials is not strong, because it is the second processing of basic fertilizers, so there is almost no environmental pollution, because most of China's basic fertilizers are powder granular, therefore, China's basic fertilizer As most of the current basic fertilizers in China are in powder and granule form, most of the small and medium-sized compound fertilizer factories in China adopt this method. At present, this kind of production technology has become more and more mature in China. The earliest domestic development and have the production technology and complete sets of equipment intellectual property rights unit for the Shanghai Research Institute of Chemical Technology.

3. Part of the slurry method

In recent years, in the TVA urea, ammonium nitrate and half slurry method and the basis of the granulation method, the domestic and the development of the use of urine or ammonium nitrate solution slurry granulation process - that is, the part of the slurry method, the technology uses urea and ammonium nitrate at high temperatures to form a high-concentration solution of the characteristics of the solution (???? 95%), due to the high temperature of the urine or ammonium nitrate solution, high solubility, the liquid phase The characteristics of large amount of urine or ammonium nitrate concentrated solution directly sprayed into the bed of the granulator, the use of urine or ammonium nitrate solution to provide the liquid phase with other solid base fertilizers and back to the Section together with the coating granulation, so that you can reduce the amount of water or steam added to reduce the water content of the granulated material, and likewise to achieve a reduction in the pelleting of the water content, drying load and reduce the purpose of energy consumption. The granulated material is dried, sieved and cooled to obtain (urea-based or nitro) compound fertilizer products. At present, the domestic development and have the intellectual property rights of the production technology unit for the Shanghai Research Institute of Chemical Technology and other twenty units.

4. melt method

Melt oil-cooled granulation system of high-concentration urea-based compound fertilizer production technology is the use of urea plant intermediate products urea solution, with ammonium phosphorus, potassium salts, the development of a successful high-quality, low-energy, low-pollution high-concentration urea-based compound fertilizer production technology - melt granulation process has been applied in the Jiangsu Hengfeng Group, black and Yinchuan fertilizer plant and other units. One of the high tower crystal elevator provided by Beijing Chenguang Xingye Machinery Co., Ltd (steel wire tape type, lifting height up to 90 meters), has been applied in Sinochem Shandong fertilizer industry.

2004-10-29 09:38 Reply

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Melt granulation process has been applied in the production of fertilizers, such as urea tower spray granulation, nitrate phosphate fertilizer tower spray granulation and biaxial granulation, ammonium nitrate tower spray granulation, ammonium urethophosphate tower spray granulation. But the process for the manufacture of high-concentration urea-based composite fertilizers in the country is still a blank, this process does not require the traditional compound fertilizer production unit in the investment and energy consumption of the largest drying system, and because of the characteristics of urea and urea-based composite fertilizers, especially suitable for urea-based high-nitrogen ratio of ternary (N, P, K) and binary (N, K or N, P) high-concentration compound fertilizer production.

Compared with the commonly used compound fertilizer manufacturing process, melt granulation process has the following advantages:

(1) Direct use of urea melt, eliminating the spray granulation process of urea melt, as well as the packaging, transportation, crushing of solid urea, simplifying the production process.

(2) The melt granulation process makes full use of the heat energy of the original molten urea, and the moisture content of the material is very low, so there is no need for the drying process, which greatly saves energy consumption.

(3) The percentage of qualified product particles in the production is very high, so the amount of return material in the production process is low (almost none).

(4) The surface of the product particles is smooth, rounded, low moisture (less than 1%), not easy to agglomerate and particles with high compressive strength (more than 30N), which has a high market competitiveness.

(5) Good operating environment, no three waste emissions, is a clean production process.

(6) It can produce high nitrogen ratio urea-based compound fertilizer products.

5. Blending method

According to the requirements of nutrient distribution ratio, a variety of non-apparent chemical reactions, particle size and roundness of the basic nitrogen, phosphorus, potassium solid fertilizers as raw materials, through a certain mixing method to formulate a uniform distribution of nutrients into blended fertilizers, the method of the process is simple, the investment cost of the device and the processing cost is relatively low, is a very practical and easy to promote the method. However, this method in the production, storage and transportation, the use of a variety of basic raw materials is very much emphasized in the particle size, weight and roundness of the same basic, so that the mixture does not occur lumps and crushing and low moisture absorption point of the phenomenon. At present, the shape and specifications of China's basic fertilizers do not yet have this condition, and then by the study showed that: uniform fertilizer in the P2O5, K2O and blended fertilizer in the P2O5, K2O is absorbed by the roots of the crop at different speeds (6 times, 4.6 times), a little bit of a difference in the effectiveness of fertilizer, in addition to the popularity of our country's fertilizer is not enough to measure the soil, and its products are not yet in our country is not yet known to the farmers and acceptance. Thus the application of the method is limited to a certain extent in China at this stage. At present, there are only a dozen or so small-scale factories in Guangdong and Tianjin. In general, the blended fertilizer industry is the fertilizer production, sales and agricultural production to achieve a higher level of fertilizer production and use of fertilizer. It can reduce fertilizer distribution, sales costs, make agricultural fertilization scientific, beneficial to the excessive application of fertilizer caused by the waste of resources and fertilizer pollution problems.

6. Extrusion method

Extrusion granulation is a solid material relying on external pressure for agglomeration of dry granulation process. It has the following advantages:

(1) the production process generally does not require drying and cooling process, especially adapted to heat-sensitive materials, while saving investment and energy consumption.

(2) The operation is simple and there is no emission of three wastes during production.

(3) It can produce high-concentration compound fertilizer with lower concentration than general compound fertilizer, and organic fertilizers and other nutrients can be added according to the needs in production.

But the extrusion granulation method also has shortcomings: ① as the key equipment extrusion granulation extruder due to equipment manufacturing and pressure parts of the material and other issues, the production of material consumption, high failure rate. ② The production capacity of the extruder is small, it is difficult to realize large-scale production. Therefore, this method is generally used for production scale below 30,000 tons/year. The method is mainly used for rare earth ammonium carbonate fertilizer. The main units with this production technology are the Shanghai Research Institute of Chemical Industry and so on.

Two, China's compound fertilizer production technology, the current situation, the main problems and the development of

1, compound fertilizer production technology

(1) the introduction of technology and equipment

Because of China's phosphorus composite fertilizer development started late, so China's farmers on the understanding of phosphorus composite fertilizer, acceptance and large-scale use of late. In order to speed up the development of China's phosphate fertilizer, after more than 10 years of efforts, a number of high-concentration phosphorus, compound fertilizer devices have been built, the proportion of high-concentration phosphorus compound fertilizer has been increased from 2% in 1988 to the current 15 to 20%, China has introduced a number of foreign representative of advanced technology and equipment, ammonium phosphorus and NPK compound fertilizer production introduction of Romanian slurry pelletizing, the U.S. Davy / TVA, the United States Jacobs, Spain Espindesa, Incro, France AZF, KT and Norway Norsk hydro and other production technology and equipment, the introduction of these technologies and equipment for the phosphorus fertilizer industry in China's start and development played an important role in promoting and facilitating the role of the relevant factories in our country have been transformed into productive forces, and some of the devices have reached and exceeded the design capacity, some of the devices are continuing to improve Some devices have reached and exceeded the design capacity, and some are being improved to meet the production standard. Some of China's research institutes, institutions of higher learning and enterprises on the introduction of advanced production technology, production equipment and production management has been digested and absorbed and combined with China's specific situation of innovation in the production of ammonium phosphate and NPK compound fertilizer technology, such as China-Arabia Fertilizer Co., Ltd. on the French AZF process improvement, the granulator in the tube reactor feed, using liquid ammonia instead of gas ammonia, the use of domestically made MAP products Instead of part of the imported phosphoric acid, so that the production capacity of the device from the original less than 480,000 tons / year to the highest production capacity of 720,000 tons / year, greatly exceeding the design capacity, and has achieved remarkable results; another example is the Jiangxi Guixi Fertilizer Plant 240,000 tons / year of ammonium phosphorus production unit of our engineers and technicians through the introduction of the same kind of device digestion, absorption and improvement of the entire construction of the project using the digestion of the absorbed The whole project construction adopts the digested and absorbed technology and domestic equipment, and the plant has basically realized localization. The plant is running well and has reached the design index. Again, for example, in view of China's national conditions, engineers and technicians of the introduction of large-scale heavy calcium device for the transformation of the heavy calcium device can be adapted to the production of NPK compound fertilizer, so that not only the production of products for the enterprise to adapt to the market, increased economic benefits, but also to make the large-scale heavy calcium device technology and spend a lot of investment to play a role in the technology and all come from the introduction of technology and equipment, digestion and absorption of technological transformation and innovation. The above examples are many in our factory.

2004-10-29 09:38 Reply

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(2) domestic technology and equipment

Pulp method

China's scientific research institutes, institutions of higher learning and enterprises through the introduction of advanced production technology, the digestion and absorption of production equipment. Have developed a number of scientific and technological achievements that have formed productivity. The sulfur-based NPK technology developed by Shanghai Research Institute of Chemical Industry and Shandong Linyi Hongri Group in combination with China's national conditions can successfully combine the production of potassium sulfate with that of ammonium phosphates and compound fertilizers, thus greatly simplifying the process and lowering the production cost. The former applies the tube reactor technology which is promoted by the state in the "Eighth Five-Year Plan" and "Ninth Five-Year Plan", and the N content of the product can be up to 15%, which has been successfully operated in Shandong Shouguang Union Group and other enterprises. The latter Shandong Linyi Hongri Group of dilute acid slurry method to expand the production scale to 10 ~ 150,000 tons / year, due to the successful use of "three" technology, making the investment cost of the device is greatly reduced, the cost of production is also lower, there are a considerable number of domestic factories using the production technology, at the same time, Sichuan University, Zhengzhou University of Technology and the Shanghai Research Institute of Chemical Technology and other domestic phosphorus ore resources have also been developed and built.

A batch of corresponding slurry ammonium phosphate and supporting NPK fertilizer plant, they have made a great contribution to the development of China's slurry ammonium phosphate and NPK fertilizer production technology. But they *** with the same characteristics of production capacity and scale is relatively small, the general size of 3 to 100,000 tons / year.

Granulation method

In addition to the above slurry method of ammonium phosphate and supporting NPK fertilizer production technology, by the Shanghai Research Institute of Chemical Industry for the secondary processing of domestic basic fertilizers into a high-concentration compound fertilizer requirements for the research and development of the solid granulation method of high-concentration compound fertilizer production technology, due to the strong adaptability of the technology, raw materials from a wide range of sources easily accessible, the processing process is relatively simple, low investment, low production costs, fast start-up, and the production of fertilizers. Low production costs, fast on the horse, production flexibility, product grade adjustment is simple and easy, strong versatility, the raw materials used are solid, the dependence on raw materials is not strong, because it is the secondary processing of basic fertilizers, so there is almost no environmental pollution problems , the process is simple, low investment, low production costs, stable and reliable operation, flexibility.

Flexible production control, the production process can be more convenient according to user requirements to adjust the NPK ratio, but also can be appropriate to add other elements, the production of more varieties of composite fertilizers and special composite fertilizers, to give full play to the characteristics of the multi-species, multi-formula, multi-specification, specialization.

The source of raw materials is wide, and it is suitable for the production of compound fertilizers of various systems: urea (urine) as the main nitrogen source for the production of urea-based NPK; ammonium chloride-ammonium phosphate-potassium salt for the production of chlorine-based NPK; potassium sulphate for the production of sulfur-based NPK; and ammonium nitrate (ammonium nitrate concentrated solution)-ammonium phosphate-potassium salt for the production of nitro-NPK, and so on.

At present, most of the small and medium-sized compound fertilizer plants in China adopt this method. Shanghai Research Institute of Chemical Industry has been promoted throughout the country, the establishment of nearly 300 sets of different sizes of production units (30,000 tons / year ~ 100,000 tons / year), but also successfully for the three Southeast Asian countries (the Philippines, Indonesia, Thailand) to establish a 70,000 tons / year, 100,000 tons / year, 50,000 tons / year, 150,000 tons / year, four sets of production units. According to incomplete statistics to the current national small and medium-sized composite fertilizer plant using this technology number (drum, garden pan) has reached more than 3,000.

2, China's compound fertilizer production in the main problems

(1) the introduction of large and medium-sized slurry phosphate ammonium, compound fertilizer production units

Phosphoric acid and ammonia supporting issues

China's introduction of large and medium-sized slurry phosphate fertilizers, compound fertilizers, and other production technology and equipment, the introduction of these technologies and equipment in our country after the engineers and technicians of the constant Digested and absorbed and efforts, has been transformed into productivity in China's factories, some devices have reached and exceeded the design capacity, in China's fertilizer production plays an important leading role. If we say that all of these devices can not give full play to the current production capacity of many reasons, there are mainly with the device supporting the supply of phosphoric acid or ammonia supply problems or supply of mineral quality is not guaranteed, there is also a lack of experience in production and management, capital turnover difficulties and other issues, due to the existence of these problems, resulting in the low rate of some of the device start-up. In this regard, there are representative plants such as: China-Arab Fertilizer Co., Ltd. of phosphoric acid used to be mainly imported by Tunisia, the quality of imported phosphoric acid, the number of prices and shipments, and other factors are different degrees of impact on the normal production. Have no choice but to take a change in production management mode and based on domestic phosphoric acid and acquisition, merger and part of the domestic MAP plant method, at present the second set of 600,000 tons / year fertilizer plant has been put into production. Then Jiangxi Guixi fertilizer plant is also affected by the supply of ammonia and the supply of ore quality is stable.

Environmental protection and pollution problems

Slurry method of phosphate fertilizer compound fertilizer because it involves the processing of phosphoric acid, so there are inevitably phosphogypsum, fluorine-containing wastewater and fluorine-containing waste gas, acid sludge, and other pollution problems, in the factory layout of the country dispersed, the problem appears more prominent. Some factories in some developed countries in the west of the world have been forced to close due to environmental problems. Today in China's environmental regulations are further strict, the factory to spend a lot of money to solve the above environmental problems which is currently facing the main problem.