WO2009070953A1

WO2009070953A1 - Method for preparing microporous mineral fertilizer from silicates rock using hydrothermal chemical reaction

Info

Publication number: WO2009070953A1
Application number: PCT/CN2008/001185
Authority: WO
Inventors: Cheng Han; Jianming Liu
Original assignee: Institute Of Geology And Geophysics Cas; Sino-Mineral Technology
Priority date: 2007-12-05
Filing date: 2008-06-18
Publication date: 2009-06-11
Also published as: CN101450875A

Abstract

The invention provides a method for preparing microporous mineral fertilizer from silicates rock using hydrothermal chemical reaction, characterized in mixing silicates rock powder, solonetz initiator powder and activator powder and making hydrothermal reaction under subhumid condition. The mineral substances contained in silicates rock can be converted to active forms which are easily absorbed by plants, with transformation rates of 65-95%. The multiplex material fertilizer produced by such method has special microporous structure.

Description

Method for preparing multi-element microporous mineral fertilizer from silicate rock by hydrothermal chemical reaction

Technical field

The invention belongs to the field of mineral fertilizer production, and particularly relates to a method for preparing multi-element microporous mineral fertilizer from silicate rock by hydrothermal chemical reaction in a semi-wet state. Background technique

Plant growth requires not only NPK, but also medium elements such as silicon, calcium, magnesium, and sulfur, as well as trace elements such as iron, manganese, boron, and rare earth. Each of the essential nutrients has its special function and cannot be Replaced by other elements.

The various fertility factors in the soil are not isolated, but interconnected and mutually constrained. According to the law of minimum nutrient, the yield of crops depends mainly on the supply of the least amount of nutrients in the soil (similar to the barrel theory, the storage capacity of the barrel depends on the twist of the shortest board), and the elements such as potassium, silicon, calcium and magnesium in the soil. The shortage seriously restricts the absorption and utilization of nitrogen and phosphorus by crops. Clearly, maintaining a nutrient balance is a key factor for a sustainable agricultural farming system.

However, for a long time, the problem of unbalanced fertilization is very prominent. Excessive application of nitrogen fertilizer, while mineral nutrients such as potassium, silicon, calcium, magnesium, iron and manganese are rarely supplemented. Long-term high yields cause large amounts of potassium, silicon and other elements in the soil to be consumed. The coordination balance has been broken and the overall fertility has been declining.

The consequences of soil fertility imbalance are: 1) the actual utilization rate of nitrogen and phosphate fertilizer is very low, and the nitrogen fertilizer is less than 30%, which not only limits the further increase of agricultural production, but also increases the agricultural production cost and also causes three-dimensional pollution of agriculture; 2) Potassium silicon The shortage of quality elements such as calcium, magnesium and sulfur causes malnutrition, not only plants are prone to pathological changes, but also the quality of agricultural products is degraded, such as melon is not fragrant, fruit is not sweet; 3) excessive application of nitrogen fertilizer on the one hand causes soil acidification, secondary salinization, Pests breed, and at the same time, it is easy to cause nitrate residues in agricultural products to exceed the standard.

Therefore, there is an urgent need for an effective multi-element mineral fertilizer which can be effectively absorbed by plants and fully supplements various nutrients required for plant growth.

We know that the soil is transformed from the rock through the geochemical weathering process of nature. About 95% of the soil solid matter is composed of various minerals derived from the weathering of the rock. However, most of these minerals are in a form that is not absorbable by plants, and only a very small fraction (3%-8%) is converted into an effective nutrient that can be absorbed by plants during weathering. It’s this small part of the effective minerals. Nutrients that allow the soil to grow plants.

However, the natural process of soil formation is long (thousands - tens of thousands of years), and the conversion rate is very low. Therefore, attempts have been made to efficiently and extensively convert various minerals in silicate rock into effective forms that plants can absorb. The preliminary work related to this can be roughly summarized as the following three aspects: 1. Converting water-insoluble potassium in potassium-containing silicate rock (also known as insoluble potassium ore) into soluble potassium and developing potassium fertilizer; 2. Using mineral waste such as iron-calcium waste and yellow phosphorus waste residue, etc.; 3. Calcining carbonate rock into lime for calcium and magnesium fertilizer. Among them, the extraction of soluble potassium from potassium-containing silicate rocks was the most studied.

At present, there are mainly three methods for preparing potassium fertilizer using potassium silicate rock, namely, calcination method or sintering method, hydrothermal chemical method, and microbial method. Among them, the existing hydrothermal chemical methods mainly include the following methods.

GB186199 discloses a method for extracting potassium from feldspar. First, the potassium-containing rock is ground into a fine powder in a ball mill or a roller mill, and then the potassium-containing rock fine powder and the dilute hydrochloric acid solution are mixed and placed in an acid-resistant colloid mill. Grinding into a high-fine suspension, and transferring the obtained high-fineness suspension to the autoclave, heat treatment at about 225 ° C (25 atm), a large amount of potassium in the potassium-containing rock is dissolved into the solution, and filtered. , Evaporation and concentration, KC1 can be obtained. The potassium-containing rock fine powder may also be mixed with an alkali solution, processed into a fine-grained suspension in a colloid mill, and then heat-treated in an autoclave, filtered, and concentrated by evaporation to obtain a KOH product.

Jumei Yamasaki conducted a high-pressure extraction of potassium from potassium feldspar with Ca(OH) ₂ slurry at 100 ° C to 400 ° C. The potassium leaching rate was 90% ( Jumei Yamasaki. J. Chem.Soc. Japan Ind Chem Sect.

1951, 54(1): 704). Chemak found that at 150 °C ~ 200 °C, the KOH solution reacted with the shale in the Opalinus region of Switzerland to form calcium cross zeolite, which on the one hand activated potassium in the shale and on the other hand because the potassium ions were in the zeolite. The cavity and channel are not filtered by water, and a long-acting potash can be prepared (JA Chermak.

Clays and clay Miner. 1993, 41(3): 365-372). Lan Jixiang from Southeast University and Yan Yongjie from East China University of Science and Technology (Lan Jixiang, Yan Yongjie, [J], 髙Technical Communication, 1994, 8: 26-28) studied the pressurized reaction conditions of slaked lime and potassium feldspar. The reaction is carried out in a FYX05A permanent magnet stirred high pressure reactor with a volume of 0.5 liter, a maximum working temperature of 350 ° C, a working pressure of 200 atm, a stirring speed of 50 to 1000 rpm, and a potassium leaching rate of potassium feldspar of 90% or more. high. The disadvantage of this leaching method is that dynamic stirring is carried out, and water and solid materials are relatively large (minimum can not be less than

8), the power consumption is large, the equipment is tightly sealed and the cost is high.

Zhao Hengqin and others from Central South University (Zhao Hengqin, Hu Petjie, Ma Hualong, et al. [J] China Manganese Industry, 2003, 20(1):

27-29) Potassium feldspar powder is placed in a 300 Ό high pressure alkaline water system to dissociate the ore to obtain AI(OH) ₃ and KOH solutions.

The inventors have also carried out research on extracting potassium from potassium-containing silicate rock (insoluble potassium ore) since 1996. Research, has won three invention patents (patent number ZLO 1100474.6, ZL01100475.4 and ZL02156824.3) ₀ on the basis of learning from domestic and foreign experience in potassium, created a new hydrothermal chemical reaction method to extract potassium, KOH, K ₂ C0 ₃ and K ₂ S0 ₄ preparations were obtained. The potassium-containing silicate rock used is mainly a special type of rock composed of authigenic silicate minerals. In this type of rock, the potassium-bearing minerals are mainly potassium feldspar, illite, glauconite, mica minerals, etc. The chemical composition has a high K ₂ 0 content, generally more than 10%. Although these patented technologies can convert the original insoluble potassium in the rock into potassium which is soluble in water, it also leaves a large amount of solid residue. These solid residues have not yet found a suitable application area, and if they are stacked for a long time, they are highly liable to cause environmental burdens and require a large amount of land. .

In summary, in the existing hydrothermal chemical reaction method for preparing potassium fertilizer from potassium-containing silicate rock, one or several elements in the rock are usually converted into plant nutrients, such as potassium fertilizer and phosphate fertilizer. , calcium and magnesium fertilizer, silicon calcium fertilizer, etc. Moreover, the potassium-containing silicate rock used in the prior art is mainly a special rock composed of autogenous silicate minerals having a relatively high content of κ ₂ ο, and there is no method for producing mineral fertilizer by using ordinary silicate rock. . More importantly, to date, there has not been an effective nutrient that can simulate the geochemical weathering process, transform the various minerals in silicate rock into plant growth, and make it unique. Structural technology. Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to provide a hydrothermal chemical reaction method capable of converting a main element and a trace element in a silicate rock into a multi-element novel mineral fertilizer which can be absorbed by a plant.

One of the solutions used by the present invention to solve its technical problems is: The use of hydrothermal chemical reaction to prepare multi-element microporous mineral fertilizer from silicate rock, the characteristics of which include the following steps:

(1) pulverizing and grinding the silicate rock and the alkaline earth activator into a powdery material;

(2) according to 1:0.5~1 silicate rock: alkaline earth activator ratio, the above powdery material is put into water, so that the ratio of the total weight of water and powdery material is 1~3:1, and stirring and mixing;

(3) hydrothermally reacting the uniformly mixed material in a closed reaction vessel at 1301 to 250 Torr for a reaction time of 5 to 24 hours;

(4) The reaction product is dried, pulverized and sieved to obtain a multi-element microporous mineral fertilizer.

The alkaline earth activators described therein include lime, light burned magnesia and dolomitic lime.

The second solution adopted by the present invention to solve the technical problem is: using a hydrothermal chemical reaction to prepare a multi-element microporous mineral fertilizer from a silicate rock, the characteristics of which include the following steps: (1) pulverizing and grinding the silicate rock, the alkaline earth activator and the activator into a powdery material;

(2) According to the ratio of silicate rock: alkaline earth activator: activator 1:0.5~1:0.01~0.25, the above powdery material is put into water so that the ratio of the total weight of water and powdery material is 1~ 3: 1, and mix and mix

Ώ

(3) mixing the homogeneous material in a closed reaction vessel at 13 (rC~25 (TC hydrothermal reaction, reaction time is 5~24 hours;

The alkaline earth activator described therein includes lime, light burned magnesia and dolomitic lime, and the activator comprises gypsum and magnesium borate.

Multi-element microporous mineral fertilizer prepared from a potassium-containing silicate rock according to the method provided by the present invention, comprising

15%~30% 枸 soluble silicon, 30%~40% 枸 soluble calcium magnesium, 4%~6% water soluble and 枸 soluble K ₂ 0, 1%~5% 枸 soluble iron, chlorine free, Microscopy of two synthetic minerals mainly consisting of tobemorite [Ca ₅ Si ₆ 0 ₁₆ (OH) ₂ .4H ₂ 0] and hydrated calcium aluminosilicate [Ca ₃ Al ₂ (Si0 ₄ )(OH) ₈ ] The crystal composition, and wherein the hydrated calcium aluminosilicate is granulated in the order of 1-5 micrometers, and the tobe mullite is flaky in the thickness of several tens to hundreds of nanometers.

The invention transforms the main elements and trace elements in the silicate rock into a multi-mineral mineral fertilizer which can be absorbed by the plant, and reforms the concept of the traditional single element fertilizer or the simple element compound fertilizer. Moreover, the method for preparing a multi-element mineral fertilizer of the present invention can rapidly and cost-effectively convert various minerals in a silicate rock into an effective form that the plant can absorb, thereby possibly ending the human being at the root. It has historically relied on the natural weathering process to obtain the state of effective mineral nutrients in the soil. DRAWINGS

Figure 1 is an X-ray powder crystal diffraction phase analysis diagram of a hydrothermal reaction product;

Figure 2 is a scanning electron micrograph of a hydrothermal reaction product. detailed description

The silicate rock used for producing the mineral fertilizer is not particularly limited in the present invention, and complicated pre-treatment such as beneficiation, roasting, and the like is not required.

The alkaline earth activator used in the present invention may be either a relatively pure industrial lime or an industrial light burned magnesia, or a dolomitic lime obtained by calcination of dolomite, wherein CaO-MgO may be in any ratio.

The activator used in the present invention may be either gypsum or magnesium borate. In the present invention, the presence of gypsum The activity of Ca(OH) ₂ or/and Mg(OH) ₂ is greatly stimulated, resulting in higher conversion. Magnesium borate can promote the disintegration and destruction of the silicon oxytetrahedron and the aluminoxy tetrahedron structure in the silicate mineral, thereby achieving the purpose of increasing the conversion rate and increasing the content of the active ingredient in the product.

In the present invention, the particle size of the solid material is selected to be less than 200 mesh (i.e., 0.074 mm or less). Excessive particle size affects the rate of reaction, resulting in a decrease in the amount of active ingredient in the product. The particles should not be too fine, otherwise the power consumption in the grinding will increase, resulting in an increase in production costs.

In the production method of the present invention, the amount of water is extremely important. Too little water does not guarantee the dissolution of the various components, while too much water reduces the throughput of the material, thereby reducing productivity. The amount of water used in the present invention is selected in accordance with the amount of the solid material so that the solid material is in a semi-wet state. In the present invention, the ratio of the amount of water to the solid material, i.e., the solid-liquid ratio, is 1:1 to 3, preferably 1:1.2 to 1.5.

In addition, the pressure in the reaction system is also important for the hydrothermal reaction. In industrial production, steam can be introduced into the reaction system to keep the reaction pressure constant. In general, the greater the pressure, the more favorable the hydrothermal reaction is. However, in view of equipment cost and evaporation of water already present in the reaction system, the pressure of the introduced vapor is preferably 0.2 to 5 MPa, more preferably 0.5 to 2 MPa, and most preferably about 1.2 to 1.3 MPa.

The reaction temperature and time are important factors in determining the effect of the hydrothermal reaction. In general, the higher temperature facilitates the disintegration and destruction of the potassium-containing silicate in the hydrothermal chemical reaction, thereby achieving the purpose of increasing the conversion rate and increasing the content of the active ingredient in the product, and also shortening the reaction time and increasing the productivity. . However, the excessively high reaction temperature requires higher and stricter heat resistance and pressure resistance performance of the reactor, resulting in an increase in equipment investment, which is not conducive to reducing production costs. On the other hand, lower temperatures result in lower conversion rates, lower levels of active ingredients in the product, and excessive reaction times, increasing production costs. When the temperature is lower than 100 ° C, i.e., lower than the boiling point of water, the hydrothermal reaction proceeds extremely slowly, and the multi-element microporous mineral fertilizer of the present invention is substantially not obtained. Therefore, the reaction temperature range of the present invention is preferably from 100 to 300 ° C, more preferably from 130 to 250 ° C, most preferably from 170 to 200 ° C, from the viewpoint of obtaining an ideal multi-element mineral fertilizer and reducing cost, and the reaction time is preferably It is 5 to 24 hours, more preferably 7 to 14 hours.

The hydrothermal reaction of the present invention is carried out under static conditions, which can greatly reduce energy consumption, make the technology simple, and is easy to implement in the process flow, and the worker is easy to operate and implement. Moreover, there is no discharge of waste water, waste gas and solid waste in the whole production process, which is a green environmental protection technology.

The results of the dissolution test on the hot water reaction product according to the procedures prescribed by the Ministry of Agriculture indicate that 65%-95% of the solid phase material composition can be dissolved in 0.5 mole hydrochloric acid solution, which is a water-soluble substance that can be absorbed by plants. Or hydrazine soluble components. The water-soluble and hydrazine-soluble K ₂ 0 content is about 4%-6% (equivalent to the potassium and calcium fertilizer currently on the market), and is a chlorine-free potassium fertilizer. It also contains 20% ± 枸 soluble silicon (achieved by the Ministry of Agriculture Silicon fertilizer standard), ≥30% bismuth-soluble calcium and magnesium, 1%-5% bismuth-soluble iron and a large proportion of other bismuth-soluble components (including various trace elements and rare earth elements in silicate rock). Therefore, this product is a good long-acting slow-release mineral fertilizer with potassium, silicon, calcium, magnesium, iron, manganese and boron.

From the results of X-ray powder crystal diffraction phase analysis of the hot water reaction product shown in Fig. 1, it can be seen that the multi-element mineral fertilizer of the present invention is mainly composed of fine crystals of the following two synthetic minerals: Tobe mullite [Ca ₅ Si ₆ 0 ₁₆ (OH) ₂ .43⁄40] and hydrated calcium aluminosilicate [Ca ₃ Al ₂ (Si0 ₄ )(OH)

Figure 2 shows the results of scanning electron microscopy analysis of the multi-element mineral fertilizer of the present invention. According to the observation of the particle size' size and the analysis of the microstructure, the particles of the new type of mineral fertilizer are very fine, and are nano-submicron; wherein the hydrated calcium aluminosilicate is micron-sized granules (particle size 1-5 microns). ), the tobemorite stone is in the form of nano-scale flakes (the thickness of the flakes is tens to hundreds of nanometers). Moreover, the mineral fertilizer also shows a highly developed microporous structure under a scanning electron microscope, so the mineral fertilizer has a loose texture and a bulk density of only 0.70-0.80 g/cm ³ , so it is also called a microporous mineral fertilizer. Due to the unique fine particles and microporous structure of the mineral fertilizer, it has very high activity, which greatly improves its ability to be dissolved and absorbed by the plant root acid. Moreover, the unique microporous structure of this product also has the functions of retaining water and ensuring fertilizer, improving soil aggregate structure, and promoting ventilation and ventilation of plant roots.

The unique fine-grained and microporous structure of this mineral fertilizer is due to the use of a unique alkaline earth activator and a semi-wet process during its preparation, and the temperature, pressure and hydrothermal reaction are controlled just right. time. The potassium silicon calcium fertilizer produced by the roasting process, the yellow phosphorus slag produced by the phosphating plant, and the silicon calcium fertilizer produced by the steel slag of the steel enterprise do not have such a microporous structure under the scanning electron microscope, and the X-ray powder crystal Diffraction phase analysis shows that it is amorphous or cryptocrystalline.

The multi-element microporous mineral fertilizer of the invention does not contain any harmful substances, and retains the natural material composition characteristics of the silicate rock itself. Like the soil formed by natural weathering, the farmland does not cause extratoxicity and pollution after application, and is suitable for Produce natural green food. Moreover, the multi-element microporous mineral fertilizer product of the invention can not cause agricultural non-point source pollution as a long-acting slow-release fertilizer.

In 2006 and 2007, in Beijing, Hebei, Jilin, Inner Mongolia, Sichuan, Guizhou, Fujian, Jiangxi, Xinjiang, Shandong, Liaoning and other places on corn, rice, wheat, waxy corn, apples, candied fruit, grapes, winter jujube, tea, Sunflower, pepper, cabbage, rapeseed, celery, broad beans, sweet potatoes and other crops carried out preliminary field fertilizer efficiency tests, and achieved good results. The increase in production of various agricultural products can reach 2%-20% respectively (see Annex 1). According to the inspection of the Grain Quality Supervision and Inspection Center of the Ministry of Agriculture, the quality of rice has also improved. Compared with rice without mineral fertilizer, the ten quality indicators (moisture, crude protein, amylose, brown rice rate, glutinous rice) are detected. Nine items in rate, whole rice rate, gel consistency, alkali value (grade) / gelatinization temperature, chalky rice rate, chalk size, whiteness (垩) The white rice rate has a different degree of improvement (see Annex 2). The invention is described in more detail below with reference to the specific embodiments thereof, but these examples are intended to be illustrative only and not to limit the scope of the invention in any way. Example 1

1) Select raw materials, including potassium-containing rocks and limes:

Potassium-containing silicate rock: from Nanshan, Miyun County, Beijing, its chemical composition (%) is as follows

X-ray powder crystal diffraction analysis indicates that the potassium-containing rock is mainly potassium feldspar, and the other is quartz.

Lime: Contains 97% of CaO (chemically pure, China Pharmaceuticals Beijing Purchasing and Supply Station).

2) Production process:

(1) pulverize the potassium-containing rock and lime to below 200 mesh, first add 30 ml of water to the plastic vessel, then add 5.000 g of potassium-containing rock ore powder and 5.000 g of lime powder to the vessel in turn, and stir evenly with a stir bar;

(2) The plastic vessel containing the sample is placed in an autoclave and reacted at 197 Torr for 7 hours;

(3) After the high pressure reactor is cooled, the plastic vessel is taken out, the reaction product is transferred to a glass watch, heated and dried in a 105 烘 oven, and ground to obtain a mineral fertilizer product.

3) In order to determine the dissolution rate of potassium in the potassium-containing mineral, the obtained product is transferred to a filter, and the soluble potassium is extracted by water. In the test, 100 ml of potassium-containing filtrate was obtained, and after dilution, the concentration of potassium in the liquid sample was measured by a flame photometer, and the measurement result was converted into a K ₂ 0 concentration of 4540 ng/l. 5.000 g of potassium-containing rock ore powder contains K ₂ 0 639.5 mg, and the leachate is equivalent to K ₂ 0 concentration of 4540 mg/l, and the shell Ij lOO ml filtrate contains K ₂ 0 454.0 mg, therefore, dissolution of potassium in potassium-containing minerals The rate was 70.99%. Example 2

1) Select raw materials, including potassium-containing rock, lime and gypsum:

X-ray powder crystal diffraction analysis indicates that the potassium-containing rock is mainly potassium feldspar, and the other is quartz. Lime: Contains 97% of Ca0 (chemically pure, purchased from China Pharmaceuticals Beijing Supply Station).

Gypsum: From the Xinjiang and Buxail County Xiazizi bentonite mining area, for the crystallized transparent gypsum, heated in a laboratory oven for 120 hours to obtain hemihydrate gypsum (CaS0 ₄ · 1/2H ₂ 0).

2) Production process:

(1) crush the potassium-containing rock, lime and hemihydrate gypsum to below 200 mesh, first in the plastic vessel

30ml of water, then add 1.000g of hemihydrate gypsum powder, 5.000g of potassium-containing rock ore powder, 4.000g of lime powder to the dish, and stir evenly with a stir bar;

(3) After the high pressure reactor is cooled, the plastic vessel is taken out, the reaction product is transferred to a glass watch, heated and dried in an oven at 105 ° C, and finely ground to obtain a mineral fertilizer product.

3) In order to determine the dissolution rate of potassium in the potassium-containing mineral, the obtained product was transferred to a filter, and the soluble potassium was extracted with water. In the test, 100 ml of potassium-containing filter solution was obtained. After dilution, the concentration of potassium in the liquid sample was measured by a flame photometer. The measurement result was converted into a K ₂ 0 concentration of 5080 mg/L 5.000 g of potassium-containing rock ore powder containing K ₂ 0 639.5 mg. When the leachate is equivalent to a K ₂₀ concentration of 5080 mg/l, 100 ml of the filtrate contains K ₂ 0 508.0 mg, and therefore, the dissolution rate of potassium in the potassium-containing mineral is 79.44%. Comparing Example 1 and Example 2, it can be seen that a certain amount of gypsum (herely hemihydrate gypsum) was added to the formulation, which stimulated the activity of lime, and the dissolution rate of potassium in the potassium-containing rock was increased by 8.45%. Example 3

1) Select raw materials, including potassium-containing rocks and limes:

Potassium-containing silicate rock: taken from Nanshan, Miyun County, Beijing, its chemical composition (%) is as follows:

X-ray powder crystal diffraction analysis indicates that the silicate rock mineral composition is mainly potassium feldspar, and the others are quartz. Lime: Contains 97% of CaO (chemically pure, China Pharmaceuticals Beijing Purchasing and Supply Station).

2) Production process:

(1) The silicate rock and lime are respectively ground to below 200 mesh to obtain silicate rock powder and lime powder; 15 ml of water is added to the plastic vessel, and then 5.700 g of silicate rock powder and 4.300 g of lime powder are added. Add to the vessel in turn, and stir to mix the materials evenly; (2) The plastic vessel containing the sample is placed in an autoclave and reacted at 191 ° C for 8 hours;

(3) After the autoclave is cooled, the plastic vessel is taken out, and the reaction product is transferred to a glass watch and heated and dried in a 105 烘 oven;

(4) The dried reaction product is ground to obtain a multi-element mineral fertilizer.

3) Measure the active ingredient content of the multi-element mineral fertilizer obtained (l.OOOg multi-element mineral fertilizer sample at

The elution amount in 100 ml of 0.5 mol/l hydrochloric acid, room temperature, dissolution time was 30 minutes, electromagnetic stirring), and the results are shown in Table 1. Table 1 Example 3 Multi-element mineral fertilizer active ingredient content (%)

Instrument used: Full spectrum direct reading plasma emission spectrometer, IRIS Advantage type, American Thermoelectric Company production Example 4

1) Select raw materials, including potassium silicate rock, lime and light burned boehmite:

Potassium-containing silicate rock: from Nanshan, Miyun County, Beijing, its chemical composition (%) is as follows;

X-ray powder crystal diffraction analysis indicated that the potassium-bearing rock mineral composition is mainly potassium feldspar, and the others are quartz. Lime: CaO content 97%, (chemically pure, China Pharmaceuticals Beijing Purchasing and Supply Station).

Light burned boehmite ore: The original ore sample was obtained from Liaoning Tiancheng Chemical Plant, and the raw ore coarse crushed sample was placed in a muffle furnace. At 70 (TC heating and constant temperature for 0.5 hour, it was taken out to obtain a light phase dominated by the glass phase. Burning magnesia ore.

2) Production process - (1) Smash the potassium-bearing rock, lime, and light-burned borax ore to below 200 mesh, first add 15 ml of water to the plastic vessel, and then add 100 mg of light burnt magnesia ore to the vessel. Powder, 5.700g of potassium-containing rock ore powder, 4,200g of lime powder, stir well with a stir bar.

(2) placing the plastic vessel containing the sample in an autoclave and reacting at 19 CTC for 8 hours;

(3) After the autoclave is cooled, the plastic vessel is taken out, the reaction product is transferred to a glass watch glass, and dried in an oven at 105 ° C; (4) The dried reaction product is ground to obtain a multi-element microporous mineral fertilizer.

3) Measure the active ingredient content of the multi-element mineral fertilizer obtained (the dissolution amount of the 1000g mineral fertilizer sample in 100ml 0.5mol/l hydrochloric acid, room temperature, dissolution time 30 minutes, electromagnetic stirring), the results are shown in Table 2. . Table 2 Example 4 Multi-element microporous mineral fertilizer active ingredient content (%)

Apparatus used: Full-spectrum direct-reading plasma emission spectrometer, IRIS Advantage type, American Thermoelectric Company produced Comparative Examples 3 and 4, it can be found that lime was added to the formula by adding an appropriate amount of light burnt magnesia ore fines. The activity can promote the disintegration and destruction of the silicon oxytetrahedron and the aluminoxy tetrahedral structure in the silicate mineral, thereby achieving the purpose of increasing the conversion rate and increasing the content of the active ingredient in the product. Example 5

1) Select raw materials, including potassium silicate rock and lime:

2) Production process:

(1) Smash the potassium-containing rock and lime to 200 mesh, first add 15ml 7 to the plastic vessel, then add 5.700g of potassium-containing rock ore powder and 4.300g of lime powder to the vessel, and stir evenly with a stir bar.

(2) placing the plastic vessel containing the sample in an autoclave and reacting at 130 ° C for 24 hours;

(3) After the autoclave is cooled, the plastic vessel is taken out, and the reaction product is transferred to a glass watch glass, and dried in an oven at 105 ° C;

(4) The dried reaction product is ground to obtain a multi-element microporous mineral fertilizer.

3) Measure the active ingredient content of the multi-element mineral fertilizer obtained (the dissolution amount of 1.000g mineral fertilizer sample in 100ml 0.5mol/l hydrochloric acid, room temperature, dissolution time is 30 minutes, electromagnetic stirring), the results are shown in Table 3. . Table 3 Example 5 multi-element microporous mineral fertilizer active ingredient content (%)

Instrument used: Full spectrum direct reading plasma emission spectrometer, IRIS Advantage type, American Thermoelectric Company production Example 6

1) Select raw materials, including potassium silicate rock and lime:

Potassium-containing silicate rock: taken from Nanshan, Miyun County, Beijing, its chemical composition (%> is as follows:

2) Production process:

(1) Smash the potassium-containing rock and lime to 200 mesh, first add 15 ml of water to the plastic vessel, then add 5.700 g of potassium-containing rock ore powder and 4.300 g of lime powder to the vessel in turn, and stir well with a stir bar.

(2) placing the plastic vessel containing the sample in an autoclave and reacting at 250 Torr for 5 hours;

(3) After the autoclave is cooled, the plastic vessel is taken out, and the reaction product is transferred to a glass watch glass and heated and dried in a 105-inch water tank;

3) Measure the active ingredient content of the multi-element mineral fertilizer obtained (the dissolution amount of the 1000g mineral fertilizer sample in 100ml 0.5mol/l hydrochloric acid, room temperature, dissolution time 30 minutes, electromagnetic stirring), the results are shown in Table 4. . Table 4 Example 6 multi-element microporous mineral fertilizer active ingredient content (%)

Instruments used: Full spectrum direct reading plasma emission spectrometer, IRIS Advantage type, American Thermoelectric Company production comparison Examples 5 and 6 can be found that high temperature is beneficial to the disintegration and destruction of potassium silicate containing structure in hydrothermal chemical reaction. Improve the conversion rate and increase the content of active ingredients in the product. Example 7

(1) Select raw materials, including:

Potassium-rich rock: taken from Nanshan, Miyun County, Beijing, its chemical composition (%) is as follows:

X-ray powder diffraction analysis indicates that the potassium-rich rock mineral composition is mainly potassium feldspar, and the others are quartz.

Baiyun Lime: Containing 53.23 % of CaO, 36.27% of MgO, and 8.07% loss on ignition, taken from the Babaoshan limestone mine in Huailai County, Hebei Province.

Semi-hydrated gypsum: purchased from the market.

(2) Put the potassium-rich rock coarse powder 5.000g, the lime coarse powder 5.000g, the hemihydrate gypsum l.OOg into the grinder and grind it thoroughly, so that the above-mentioned material has a particle size of less than 200 mesh, and uniformly mix and add in the plastic vessel. 16.5ml of water, then transfer the material to a plastic container and mix well with a glass rod;

(3) The plastic vessel containing the sample is placed in a pressure reactor and kept at a constant temperature of 193 ° C for 8 hours;

(4) After the autoclave is cooled, the plastic vessel is taken out, the reaction product is transferred to a filter, and filtered, and 101 ml of a potassium-containing extract is obtained in the test;

(5) Dilute the extract by 20x10 = 200 times (two-stage dilution), determine the potassium and sodium concentrations in the sample by flame photometer, and convert the results into K ₂ 0 and Na ₂ 0 concentrations of 6400 mg/l and 260 mg, respectively. /l, the Na ₂ 0 / K ₂ 0 concentration ratio is 0.0406;

(6) 5. 000 g of potassium-rich rock ore powder contains K ₂ 0 674.0 mg, and the extract is equivalent to K ₂ 0 concentration of 6400 mg/l, then 101 ml contains K ₂ 0 646.4 mg, therefore, the conversion yield of potassium in potassium-rich rock (646.4÷674.0) xlOO % =95.91 %.

As can be seen from Example 7, the maximum conversion rate of the insoluble potassium in the raw material to soluble potassium can reach 95.91%.

Example 8: (5-ton industrial preparation test)

1) Select raw materials, including potassium silicate rock, lime and gypsum:

Potassium-containing silicate rock: 宣 from Xuanhua, Zhangjiakou City, Hebei Province, its chemical composition (%) is as follows:

X-ray powder diffraction analysis indicates that the mineral composition is mainly potassium feldspar and illite, and the others are quartz. Lime: Containing 84% CaO, containing Mg0 3%, produced by Xuanhua Iron and Steel Company Longyang Calcium Plant. Gypsum: Dihydrate gypsum, purchased from Xuanhua Building Materials Store.

2) Preparation process:

(1) The potassium silicate rock, lime and gypsum are respectively ground to below 200 mesh to obtain potassium silicate rock powder, lime powder and gypsum mineral powder; the three raw materials are proportioned according to the following table - Table 5 Example 原料 Raw material ratio of multi-element microporous mineral fertilizer

(2) First put 1270L tap water in the storage tank, then add lOOKg gypsum powder, 500Kg potassium silicate rock powder, 400Kg lime powder to the water in turn, and stir to mix the materials, and prepare 5 Tons of material (ie, 5 cans of material).

(3) The material was transferred to a high pressure reactor, and subjected to high pressure steam (0.95 to 1.05 MPa), and reacted at 183 Torr for 10 hours.

(4) After the completion of the hydrothermal chemical reaction, the pressure is lowered and the temperature is lowered. The reaction kettle is smashed, the reaction product is taken out, and it is naturally air-dried. After the powder is crushed, it is a multi-element microporous mineral fertilizer.

3) Sampling and analyzing the reaction products after air drying, the active ingredient content is listed in Table 4 (1.OOOg mineral fertilizer sample dissolved in 100ml 0.5mol/l hydrochloric acid, room temperature, dissolution time is 30 minutes, electromagnetic stirring) . Table 6 Example 7 Active ingredient content of multi-element microporous mineral fertilizer (%)

Instrument: direct reading full spectrum of plasma emission spectrometer, IRIS Advantage type, produced by Thermo ignition loss of the mineral fertilizer sample was 16.20%, the bulk specific gravity of 0.755g / _C m ^3. Example 9: (40 ton industrial test)

1) Select raw materials, including:

Potassium-containing silicate rock: 宣 from Xuanhua, Zhangjiakou City, Hebei Province, chemical composition (%) is as follows:

Si0 ₂ Τί0 ₂ ΑΙΟί Fe _z 0 ₃ +Fe0 MnO CaO MgO Na ₂ 0 Ρ'Λ Total loss on ignition 57. 22 0. 57 18. 34 6. 09 0. 06 0. 33 1. 12 12. 01 0. 07 0. 11 3. 60 99. 52

X-ray powder diffraction analysis indicates that the mineral composition is mainly potassium feldspar and illite, and the others are quartz. Lime: Contains 84% of Ca0, contains 3% of Mg0, and is produced by Xuanhua Iron and Steel Company Longyang Calcium Plant.

Light burned boehmite: The ore sample was obtained from Liaoning Tiancheng Chemical Plant. The crude ore sample was placed in a muffle furnace, heated at 700 °C for 0.5 hour, and taken out to obtain a glass-based light burn. Boraxite ore.

2) Production process:

(1) grinding potassium silicate rock, lime, and light burned boehmite to below 200 mesh to obtain potassium silicate rock powder, lime powder and light burned magnesia ore powder; Proportion of the following table: Table 7 Example 8 Raw material ratio of multi-element microporous mineral fertilizer

(2) First, put 1400L tap water in the storage tank, then add 10Kg light burned borax powder, 570Kg potassium silicate rock powder, 420Kg lime powder to the water in turn, and stir to mix the materials evenly. Formulate 40 tons of material (ie, prepare 40 cans of material).

(3) Transfer the material to a pressure reactor, pass high pressure steam (0.95~1.05MPa), and carry out hydrothermal chemical reaction at 180 °C for 14 hours.

(4) After the completion of the hydrothermal chemical reaction, the pressure is lowered and cooled, the reaction vessel is opened, the reaction product is taken out, and it is naturally air-dried, and the elemental microporous mineral fertilizer is pulverized.

The sample of the 40 tons of product obtained after air drying is collected from hundreds of points, and combined, mixed thoroughly, and the sample is divided by a diagonal four-point method to about 2 kg, and the material composition of the system is performed. Microstructure analysis. The test results are as follows:

A. Microporous mineral fertilizer chemical analysis data:

Table 8 Main element content (wt%) of the multi-element microporous mineral fertilizer of Example 8.

Table 9 Trace element content (mg/k _g , ie ppm) of the multi-element microporous mineral fertilizer of Example 8. Component B Ba Cd Co Cr Cu Mo Ni Pb Sr V Zn Content 559.0 262.4 3.85 10.15 58.65 5.85 10.15 53.95 10.15 216.85 141.75 81.5 Apparatus used: Sequential X-ray fluorescence spectrometer, XRF-1500, manufactured by Shimadzu Corporation, Japan

B. Phase composition

X-ray powder crystal diffraction analysis (see Figure 1), the microporous mineral fertilizer from tobe mullite [Ca ₅ Si ₆ 0 ₁₆ (OH) ₂ .4H ₂ 0], hydrated calcium aluminosilicate [Ca Phase composition of ₃ Al ₂ (Si0 ₄ )(OH) ₈ ] and calcium carbonate (apparatus: X-ray diffractometer, model D/MAX-2400, manufactured by Nippon Rigaku Corporation).

C. Observation and analysis of microscopic morphology and structure of scanning electron microscopy

Scanning electron microscopy (LE01450VP type, produced by Leo, Germany) was used to observe and analyze the microstructure of mineral fertilizers. It was found that the two main synthetic minerals of microporous mineral fertilizers are nano-submicron-sized fine particles. One is spherical (hydrated calcium aluminosilicate), the other mineral is flaky (tobe mullite), and a large number of micropores are distributed (see Figure 2), so it is called microporous mineral fertilizer.

D. Heap weight

The bulk specific gravity of the new microporous mineral fertilizer was determined by the conventional volumetric flask method and found to be 659 g/1 or 0.659 g/cm3. Obviously, its specific gravity is small, which is consistent with the large number of micropore distributions observed in SEM microscopic observations.

E. Determination of the dissolved component (ie active ingredient) in 0.5 Peng 1/1 hydrochloric acid solution

Grind microporous mineral fertilizer to below 200 mesh, take 1.000 g sample, place in a triangular flask, add 100ml

0.5 rn _O l / l hydrochloric acid solution, stirred at room temperature (2 Torr, on a magnetic stirrer for 30 minutes, filtered, and the components eluted in the filtrate were measured. The results are shown in Table 8 and Table 9: Table 10 Example 8 Active ingredient of multi-element microporous mineral fertilizer (%)

Table 11 Effective trace element content (mg/kg, ie ppm) of the multi-element microporous mineral fertilizer of Example 8. Component B Ba Cd Co Cr Mo Ni Pb Sr V Zn Cu Contains a 458.70 78.70 0.20 2.90 23.10 2.90 30.30 2.90 211.89 94.30 18.20 0.00 Instrument used: Full spectrum direct reading plasma emission spectrometer, IRIS Advantage type, US Thermoelectric Company production from the above implementation As can be seen, the multi-element microporous mineral fertilizer prepared from silicate rock using the hydrothermal chemical reaction of the present invention contains about 4% to 6% of water-soluble and hydrazine-soluble K ₂ 0 (equivalent to a chlorine-free potassium fertilizer). , 15%~30% 枸 soluble silicon, 30%~40% 枸 soluble calcium magnesium, 1%~5% 枸 soluble iron and a large proportion of other 枸 soluble components (including each in silicate rock) Trace elements and rare earth elements). Therefore, this product is a good multi-element sustained-release long-acting mineral fertilizer such as potassium, silicon, calcium, magnesium, iron, manganese and boron.

Claims

A method for producing a multi-element microporous mineral fertilizer from a silicate rock by hydrothermal chemical reaction, the method comprising the steps of:

(2) According to the 1:25~1 silicate rock: alkaline earth activator ratio, the above powdery material is put into the water, right

The ratio of the total weight of the water to the powdery material is 1~3:1, and the mixture is stirred and mixed;

(3) hydrothermally reacting the uniformly mixed material in a closed reactor at 13 °C (rC~250 ° C, the reaction time is 5 to 24 hours;

begging

The method according to claim 1, wherein the powdery material in the step (1) has a particle size of 200 mesh or less.

3. The method of claim 1 wherein the weight ratio of water to powdered material in step (2) is 1.2~

1.5: 1.

The method according to claim 1, wherein the hydrothermal reaction in the step (3) is carried out at 170 ° C to 20 (TC for 7 to 14 hours).

5. A method for producing a multi-element microporous mineral fertilizer from a silicate rock using a hydrothermal chemical reaction, the method comprising the steps of:

(1) pulverizing and grinding the silicate rock, the alkaline earth activator and the activator into a powdery material;

(2) According to the ratio of silicate rock: alkaline earth activator: activator 1:0.5~1:0.01~0.25, put the above powdery material into water, so that the ratio of total weight of water and powdery material is 1 ~ 3: 1, and mix and mix.

(3) mixing the homogeneous material in a closed reactor at 130 ° C ~ 25 (TC hydrothermal reaction, reaction time is 5 ~ 24 hours;

6. The method of claim 5 wherein said magnesium borate comprises boehmite ore and light burnt boehmite.

7. The method according to claim 5, wherein the powdery material in the step (1) has a particle size of 200 mesh or less. '

The method according to claim 5, wherein the weight ratio of the water to the powdery material in the step (2) is from 1.2 to 1.5:1.

9. The method according to claim 5, wherein the reaction in the step (3) is carried out at 170 ° C to 20 (TC for 7 to 14 hours).