CN111635762A - A method for preparing soil conditioner by utilizing graphite high silicon solid waste - Google Patents

Abstract

The invention discloses a method for preparing a soil conditioner by using graphite high-silicon solid waste, comprising the following steps: (1) grinding the graphite solid waste to obtain graphite solid waste powder, and then mixing the graphite solid waste powder and an activator Evenly, the mixed powder is obtained, the mass ratio of the graphite solid waste powder and the activator is 55-80:20-45, and the activator includes the following components by weight: 89-96 parts of lime, 1-3 parts of sodium sulfate, carbonic acid 1 to 3 parts of sodium, 1 to 3 parts of potassium hydroxide and 1 to 2 parts of alumina; (2) adding water to the mixed powder and mixing evenly to obtain a slurry; The autoclaving temperature is 140-190 DEG C, the autoclaving time is 8-16 hours, and the autoclaved product is dried and ground to obtain the soil conditioner. The invention realizes the resource utilization of the graphite solid waste, and the prepared soil conditioner improves the soil fertility and water retention capacity.

Description

A kind of method for preparing soil conditioner by using graphite high silicon solid waste

technical field

The invention belongs to the technical field of waste material recycling, and in particular relates to a method for preparing a soil conditioner by using graphite high-silicon solid waste.

Background technique

As an important non-metallic mineral material with high electrical conductivity, high thermal conductivity, acid and alkali corrosion resistance and lubrication, graphite has a wide range of applications in many industrial fields. In recent years, with the rapid development of my country's industrial technology, the demand for graphite is increasing day by day. Graphite mines will produce a large amount of waste rock in the mining process and a large amount of tailings in the purification process. These graphite solid wastes cause environmental hazards such as occupation of land, pollution of water and soil, and a huge safety hazard of dam failure. According to statistics, about 20 tons of graphite tailings are discharged on average for every ton of graphite products produced, and there are more than 100 large and small graphite tailings ponds in my country, and the average service life is only 5 years. These tailings ponds pose a huge threat to the safety of mining areas. . The resource utilization of graphite solid waste is one of the main ways to solve the above problems.

As a big agricultural country, my country's land resources are not optimistic. On the one hand, the development of urbanization has occupied a lot of good cultivated land and the development of industry has made soil pollution more and more serious, resulting in the increase of heavy metal content in soil, which has caused great harm to human health. threaten. On the other hand, the continuous increase of soil erosion has caused land degradation that is no longer suitable for crop growth, and people's unreasonable farming, continuous cropping, and excessive use of chemical fertilizers and pesticides have resulted in increasingly serious soil degradation, decreased soil fertility, and reduced productivity. The increasingly serious soil problems have prompted the development of soil conditioners. The use of soil conditioners has a significant effect on soil improvement. However, due to the high cost, large dosage and single function of most soil conditioners, they cannot be widely promoted.

Therefore, it is of great significance to develop a soil conditioner with low cost, multiple functions, and resource utilization of graphite solid waste for solving graphite solid waste and improving soil problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned technical deficiencies, and propose a method for preparing soil conditioner by utilizing graphite high-silicon solid waste. Effectively passivate heavy metal ions in the soil, provide plants with abundant and effective silicon, sodium, potassium and other plant nutrients, improve soil fertilizer and water retention capacity and enhance soil permeability.

In order to achieve the above-mentioned technical purpose, the technical scheme of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

S1, with graphite solid waste grinding, obtain graphite solid waste powder, then described graphite solid waste powder and activator are mixed uniformly, obtain mixed powder, wherein, the mass ratio of described graphite solid waste powder and activator is 55-80: 20-45, the activator comprises the following components by weight: 89-96 parts of lime, 1-3 parts of sodium sulfate, 1-3 parts of sodium carbonate, 1-3 parts of potassium hydroxide and aluminum oxide 1-2 servings;

S2. Add water to the mixed powder and mix evenly to obtain a slurry. After standing for curing, the slurry is subjected to autoclaving. The autoclaving temperature is 140-190° C. The pressure-treated product is dried and ground to obtain a soil conditioner.

Compared with the prior art, the beneficial effects of the present invention include:

1. In the present invention, the graphite solid waste is used as the main raw material, and lime, sodium sulfate, sodium carbonate, potassium hydroxide and alumina are added according to the activator prepared in a certain proportion, and the graphite solid waste powder and the activator are autoclaved. After treatment, silicates such as calcium silicate, sodium silicate and potassium silicate, and zeolite phases are obtained. The obtained silicates not only significantly improve the conversion rate of effective silicon, provide abundant silicon elements for plants, but also provide plants with abundant silicon. Provides rich potassium and sodium and other nutrients;

2. The main component of the soil conditioner obtained by autoclaving is calcium silicate, which has the characteristics of strong adsorption, low specific gravity and many pores. The required elements and water are lost, the soil fertilizer retention and water holding capacity are improved, and the heavy metal ions in the soil can be adsorbed to prevent the migration of the heavy metal ions, thereby reducing the biological activity of the heavy metal ions; in addition, the obtained sodium silicate and potassium silicate are Soluble silicates, calcium silicates are insoluble silicates, soluble silicates can immediately release the effective elements when they act on the soil, while calcium silicates and zeolite have many pores, which can be slowly released after adsorbing the elements required by vegetation. , through the coordination of soluble silicates and insoluble silicates with many pores and strong adsorption and zeolite, thereby increasing the action time of nutrients and improving the utilization rate of fertilizers;

3. The zeolite phase contained in the soil conditioner obtained by autoclaving also has the characteristics of strong adsorption, low specific gravity and many pores. It works together with calcium silicate to further improve soil fertility and water retention. ability, and reduce the biological activity of heavy metal ions in soil;

4. The present invention uses the discarded graphite solid waste as the main raw material, and prepares it into a soil conditioner, which can solve the land occupation of the graphite solid waste and the harm caused to the environment, and realize the resource utilization of the graphite solid waste, In addition, the preparation method provided by the invention has the advantages of simple operation, mild reaction conditions and low cost of raw materials, and is suitable for industrial mass production and application.

Description of drawings

Fig. 1 is the process flow diagram of utilizing graphite high silicon solid waste to prepare soil conditioner provided by the embodiment of the present invention;

FIG. 2 is a process flow diagram of preparing graphite solid waste powder according to an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

FIG. 1 is a process flow diagram of preparing a soil conditioner by using graphite high-silicon solid waste provided by an embodiment of the present invention. As shown in FIG. 1 , an embodiment of the present invention provides a method for preparing a soil conditioner by using graphite high-silicon solid waste , including the following steps:

(1) Grinding the graphite solid waste to obtain the graphite solid waste powder, and then mixing the graphite solid waste powder and the activator evenly to obtain a mixed powder, wherein the mass ratio of the graphite solid waste powder and the activator is 55-80 : 20～45 parts, the activator comprises the following components by weight: 89～96 parts of lime, 1～3 part of sodium sulfate, 1～3 part of sodium carbonate, 1～3 part of potassium hydroxide and 1～2 part of alumina;

(2) Add water to the mixed powder and mix evenly to obtain a slurry. After standing and curing the slurry, autoclave treatment. The product is dried and ground to obtain a soil conditioner.

The embodiments of the present invention provide a method for preparing a soil conditioner by using graphite high-silicon solid waste. The graphite solid waste is ground to obtain graphite solid waste powder, and then the graphite solid waste powder is mixed with lime, sodium sulfate and sodium carbonate. The activators of , potassium hydroxide and alumina are evenly mixed, and after the slurry is prepared, it is then subjected to autoclaving at a certain temperature after standing and curing. During the autoclaving process, the SiO ₂ Hydrothermal reaction with lime generates calcium silicate, SiO ₂ reacts with sodium sulfate, sodium carbonate and potassium hydroxide to generate sodium silicate and potassium silicate respectively, SiO ₂ reacts with alumina to generate zeolite phase, in the embodiment of the present invention by The dosage of lime, sodium sulfate, sodium carbonate, potassium hydroxide and alumina in the activator is controlled to prepare different amounts of silicate phases and zeolite phases, wherein sodium silicate and potassium silicate are soluble silicates, It can improve the conversion rate of effective silicon, not only provide abundant silicon for plants, but also provide various nutrients such as potassium and sodium, and the soluble silicate can release the nutrients immediately after it acts on the soil; and silicon Calcium acid and zeolite are not easy to dissolve, but they have strong adsorption, low specific gravity and many pores. They can absorb nutrients in fertilizers and store them, and then slowly release them into the soil. It is matched with zeolite to increase the action time of nutrient elements and improve the utilization rate of fertilizers. In addition, due to the characteristics of strong adsorption, low specific gravity and many pores, the insoluble calcium silicate and zeolite phases can not only absorb the elements and water required by vegetation in the soil, prevent the loss of elements and water required by vegetation, and improve soil fertility. It can also absorb heavy metal ions in the soil, prevent the migration of heavy metal ions, and then reduce the biological activity of heavy metal ions. The method for preparing a soil conditioner by using graphite high-silicon solid waste provided in the embodiment of the present invention is prepared by mixing graphite solid waste powder and an activator containing lime, sodium sulfate, sodium carbonate, potassium hydroxide and alumina uniformly. After the slurry is formed, the soil conditioner is prepared by autoclaving at a certain temperature after standing and curing. The preparation method effectively utilizes the graphite solid waste, and the prepared soil conditioner can effectively blunt the It can reduce heavy metal ions in the soil, provide plants with abundant effective silicon, sodium, potassium and other plant nutrients, improve soil fertilizer and water retention capacity and enhance soil permeability.

In some preferred embodiments of the present invention, the graphite solid waste is waste rock produced by mining graphite or graphite purification tailings, and the SiO ₂ content of the graphite solid waste is higher than 40%.

Fig. 2 is a process flow diagram of preparing graphite solid waste powder provided by the embodiment of the present invention. As shown in Fig. 2, if the graphite solid waste in step (1) of the embodiment of the present invention is the waste rock produced by mining graphite, then After crushing it first, grind the ore to below 200 mesh to obtain graphite solid waste powder; if the graphite solid waste in step (1) in the embodiment of the present invention is graphite purification tailings, the graphite purification tailings are first calcined Afterwards, grind the ore to below 200 mesh to obtain graphite solid waste powder.

In some preferred embodiments of the present invention, the graphite-purified tailings are calcined at 400-500° C. for 1-3 hours to remove the organic solvent in the graphite-purified tailings and prevent them from entering the soil.

In some preferred embodiments of the present invention, when preparing the slurry in step (2), add water to the mixed powder until the moisture content reaches 50-200%, and then mix evenly; the moisture content of the slurry is optimized to ensure oxidation Silica in calcium and graphite solid waste powder is better for hydration reaction.

In some preferred embodiments of the present invention, in step (2), the slurry is left to stand for maintenance for 5-8 hours to ensure that the activator fully activates the graphite solid waste powder.

In some preferred embodiments of the present invention, the autoclave pressure during autoclaving is 0.8-1.2MPa; in order to promote the sufficient reaction between the silica and the activator in the graphite solid waste powder to generate the required silicate phase and zeolite Mutually.

In some preferred embodiments of the present invention, the autoclaved product is dried to a moisture content of 7-12%.

In some preferred embodiments of the present invention, the dried product is dispersed to -100 mesh by dry method; to ensure that the prepared soil conditioner has a larger specific surface area.

When using the soil conditioner prepared by the present invention, 3%, 5% or 10% can be added to the soil, and those skilled in the art can also add it according to actual needs. The present invention does not further use the soil conditioner. limited.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The experimental methods in the present invention are conventional methods unless otherwise specified. The experimental materials used in the present invention are all commercially available unless otherwise specified; the _SiO2 content in the waste rock produced by mining graphite used in the following examples is 68.3%, and the _SiO2 content in the graphite purification tailings is 74.9% , the content of CaO in the lime powder used is 70%, the content of sodium sulfate used is ≥99%, the content of sodium carbonate used is ≥99%, the content of potassium hydroxide used is ≥99%, and the content of alumina used is ≥99%.

Example 1:

Embodiment 1 of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

(1) after the waste rock produced by mining graphite is crushed, then through grinding and screening, obtain the graphite solid waste powder below 200 meshes; Take by weighing raw materials according to the following parts by weight: 91 parts of lime, 2 parts of sodium sulfate, sodium carbonate 2 parts of potassium hydroxide, 3 parts of potassium hydroxide and 2 parts of alumina, mix the above-mentioned raw materials evenly to obtain an activator; take 65 parts of graphite solid waste powder and 35 parts of activator, put them into a vortex mixer, stir for 10min, Mix evenly to obtain mixed powder;

(2) Add water to the mixed powder according to the mass ratio of the mixed powder to water of 1:1, stir for 10 minutes and mix evenly to obtain a slurry, the moisture content of the slurry is 100%, and the slurry is allowed to stand at room temperature for curing After 8h, put the slurry into an autoclave for autoclave treatment, the autoclave pressure is 0.8MPa, the autoclave temperature is 150°C, and the autoclave time is 12h; Drying treatment was carried out at 105° C. for 12 hours until the water content of the product was 7%, and then the dried product was crushed to -100 mesh with a pulverizer to obtain a soil conditioner.

The effective silicon content of the soil conditioner prepared by the method in Example 1 was 22.18%.

Example 2:

Embodiment 2 of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

(1) after crushing the waste rock produced by mining graphite, then through grinding and screening, obtain the graphite solid waste powder below 200 meshes; Take by weighing raw materials according to the following parts by weight: 93 parts of lime, 2 parts of sodium sulfate, sodium carbonate 2 parts of potassium hydroxide, 2 parts of potassium hydroxide and 1 part of alumina, mix the above-mentioned raw materials evenly to obtain an activator; take 75 parts of graphite solid waste powder and 25 parts of activator, put them in a vortex mixer, stir for 10min, Mix evenly to obtain mixed powder;

(2) Add water to the mixed powder according to the mass ratio of mixed powder to water of 1:0.8, stir for 10 minutes and mix evenly to obtain a slurry, the moisture content of the slurry is 80%, and the slurry is allowed to stand at room temperature for curing After 7h, put the slurry into an autoclave for autoclave treatment, the autoclave pressure is 0.8MPa, the autoclave temperature is 160°C, and the autoclave time is 11h; Drying treatment was carried out at 105° C. for 11 hours until the water content of the product was 9%, and then the dried product was crushed to -100 mesh with a pulverizer to obtain a soil conditioner.

The effective silicon content of the soil conditioner prepared by the method in Example 2 was 21.79%.

Example 3:

Embodiment 3 of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

(1) after crushing the waste rock produced by mining graphite, then through grinding and screening, obtain the graphite solid waste powder below 200 meshes; Take by weighing raw materials according to the following parts by weight: 92 parts of lime, 2 parts of sodium sulfate, sodium carbonate 2 parts of potassium hydroxide, 3 parts of potassium hydroxide and 1 part of alumina, mix the above-mentioned raw materials evenly to obtain an activator; take 70 parts of graphite solid waste powder and 30 parts of activator, put them into a vortex mixer, stir for 10 minutes, Mix evenly to obtain mixed powder;

(2) Add water to the mixed powder according to the mass ratio of mixed powder to water of 1:0.6, stir for 10 minutes and mix evenly to obtain a slurry, the moisture content of the slurry is 60%, and the slurry is allowed to stand at room temperature for curing After 6h, put the slurry into an autoclave for autoclaving, the autoclave pressure is 0.8MPa, the autoclave temperature is 170°C, and the autoclave time is 10h; Drying treatment was carried out at 105° C. for 10 hours until the water content of the product was 11%, and then the dried product was crushed to -100 mesh with a pulverizer to obtain a soil conditioner.

The effective silicon content of the soil conditioner prepared by the method in Example 3 was 22.37%.

Example 4:

Embodiment 4 of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

(1) After calcining the purified graphite tailings at 400°C for 2 hours, then grinding and sieving to obtain graphite solid waste powder below 200 meshes; take by weighing the raw materials according to the following parts by weight: 89 parts of lime, 2 parts of sodium sulfate 3 parts of sodium carbonate, 3 parts of potassium hydroxide and 3 parts of aluminum oxide, mix the above-mentioned raw materials evenly to obtain an activator; take 65 parts of graphite solid waste powder and 35 parts of activator, put them in a vortex mixer , stir for 10min, and mix well to obtain mixed powder;

(2) Add water to the mixed powder according to the mass ratio of the mixed powder to the water as 1:1, stir for 10 minutes and mix evenly to obtain a slurry, the moisture content of the slurry is 100%, and the slurry is allowed to stand at room temperature for curing After 8h, put the slurry into an autoclave for autoclaving, the autoclave pressure is 0.8MPa, the autoclave temperature is 140°C, and the autoclave time is 14h; Drying treatment was carried out at 105° C. for 12 hours until the water content of the product was 7%, and then the dried product was crushed to -100 mesh with a pulverizer to obtain a soil conditioner.

The effective silicon content of the soil conditioner prepared by the method in Example 4 was 23.58%.

Example 5:

Embodiment 5 of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

(1) After calcining the purified graphite tailings at 500°C for 1 hour, then grinding and sieving to obtain graphite solid waste powder below 200 meshes; take by weighing the raw materials according to the following parts by weight: 92 parts of lime, 2 parts of sodium sulfate 2 parts of sodium carbonate, 2 parts of potassium hydroxide and 2 parts of aluminum oxide, mix the above-mentioned raw materials evenly to obtain an activator; take 75 parts of graphite solid waste powder and 25 parts of activator, put them into a vortex mixer , stir for 10min, and mix well to obtain mixed powder;

(2) Add water to the mixed powder according to the mass ratio of mixed powder to water of 1:0.8, stir for 10 minutes and mix evenly to obtain a slurry, the moisture content of the slurry is 80%, and the slurry is allowed to stand at room temperature for curing After 7h, put the slurry into an autoclave for autoclave treatment, the autoclave pressure is 0.8MPa, the autoclave temperature is 160°C, and the autoclave time is 11h; Drying treatment was carried out at 105° C. for 11 hours until the water content of the product was 9%, and then the dried product was crushed to -100 mesh with a pulverizer to obtain a soil conditioner.

The effective silicon content of the soil conditioner prepared by the method in Example 5 was 22.79%.

Example 6:

Embodiment 6 of the present invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, comprising the following steps:

(1) After calcining the purified graphite tailings at 450°C for 1 hour, then grinding and sieving to obtain graphite solid waste powder below 200 meshes; take by weighing the raw materials according to the following parts by weight: 96 parts of lime, 1 part of sodium sulfate 1 part of sodium carbonate, 1 part of potassium hydroxide and 1 part of aluminum oxide, mix the above-mentioned raw materials evenly to obtain an activator; take 70 parts of graphite solid waste powder and 30 parts of activator, put them into a vortex mixer , stir for 10min, and mix well to obtain mixed powder;

(2) Add water to the mixed powder according to the mass ratio of mixed powder to water of 1:0.6, stir for 10 minutes and mix evenly to obtain a slurry, the moisture content of the slurry is 60%, and the slurry is allowed to stand at room temperature for curing After 6h, put the slurry into an autoclave for autoclaving, the autoclave pressure is 0.8MPa, the autoclave temperature is 190°C, and the autoclave time is 8h; Drying treatment was carried out at 105° C. for 10 hours until the water content of the product was 11%, and then the dried product was crushed to -100 mesh with a pulverizer to obtain a soil conditioner.

The effective silicon content of the soil conditioner prepared by the method in Example 6 was 23.62%.

The soil amendments prepared in Examples 1 to 6 were added to the soil to test their effects, and the tests were specifically carried out as follows:

1. Test sample: select the soil with a cadmium content of 3.19mg/kg and a soil bulk density ^of 1.25g/cm as the experimental culture soil, divide the experimental culture soil into 7 equal parts, each weight is 5kg, and each part of the experimental culture soil 1.5g/kg of urea and 1g/kg of calcium dihydrogen phosphate were added to the medium to obtain 7 identical experimental nutrient cultivated soils, and the 7 experimental nutrient cultivated soils were divided into control group and test group:

(1) Control group: randomly select a group of experimental nutrient cultivation soil, without adding any soil conditioner, as a blank control group;

(2) Test group: the soil conditioners prepared in Examples 1 to 6 were added to each group of experimental nutrient cultivation soil, respectively, as test groups 1 to 6, the soil conditioner dosage was 100 g/kg (with the weight of the experimental nutrient cultivation soil). as a benchmark)

2. Operation procedure: Stir each group of experimental nutrient cultivation soil in the control group and the experimental group evenly, add 1000 ml of deionized water to each, and after 7 days of outdoor static cultivation, measure the bulk density, porosity, moisture content and Cd content of the experimental nutrient cultivation soil. , ammonium nitrogen leaching rate, nitrate nitrogen leaching rate and phosphorus leaching rate;

Among them, the leaching rate was tested by the following method: 50g samples were taken from each group of experimental nutrient culture soil, each sample was rinsed with 800ml deionized water, the leaching solution was collected, and the available nitrogen, available phosphorus, and heavy metal ions Cd in the solution were measured. content;

The bulk density, porosity and water content of the experimental nutrient culture soil were all determined by conventional methods in the field, and will not be described in detail here.

3. Test results: The test results are shown in Table 1.

Table 1 The index values of soil in Examples 1-6 and Comparative Example

It can be seen from Table 1 that the capacity of the soil after the soil amendment prepared by the present invention is added to the soil is reduced, the porosity is increased, and the water content is also increased, indicating that the use of the soil amendment prepared by the present invention can increase the The permeability of the soil improves the ability of soil to retain fertilizer; the leaching amount of Cd ²⁺ in the soil with soil amendments is greatly reduced than that in the control group, indicating that soil amendments can effectively reduce the amount of Cd ^{2+ +} Converted into a form that is difficult for plants to absorb; the leaching rate of nitrogen, phosphorus and other elements in the soil with soil conditioner is significantly reduced, indicating that the soil conditioner has a good ability to retain fertilizer and greatly improve the utilization rate of fertilizer.

The specific embodiments of the present invention described above do not limit the protection scope of the present invention. Any other corresponding changes and modifications made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

Claims (9)

1. A method for preparing a soil conditioner by utilizing graphite high-silicon solid waste is characterized by comprising the following steps:

s1, grinding graphite solid waste to obtain graphite solid waste powder, and uniformly mixing the graphite solid waste powder with an activating agent to obtain mixed powder, wherein the mass ratio of the graphite solid waste powder to the activating agent is 55-80: 20-45, wherein the activating agent comprises the following components in parts by weight: 89-96 parts of lime, 1-3 parts of sodium sulfate, 1-3 parts of sodium carbonate, 1-3 parts of potassium hydroxide and 1-2 parts of aluminum oxide;

s2, adding water into the mixed powder, uniformly mixing to obtain slurry, standing and curing the slurry, then carrying out autoclaved treatment, wherein the autoclaved temperature is 140-190 ℃, the autoclaved time is 8-16 h, and drying and grinding the autoclaved product to obtain the soil conditioner.

2. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste as the claim 1, wherein the graphite solid waste is waste stone generated by graphite mining or graphite purification tailings, and the SiO of the graphite solid waste is₂The content is higher than 40%.

3. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste as the claim 2 is characterized in that if the graphite solid waste is waste stone generated by exploiting graphite, the waste stone is crushed firstly and then ground to below 200 meshes to obtain graphite solid waste powder; if the graphite solid waste is graphite purification tailings, calcining the graphite solid waste, and grinding the graphite solid waste to below 200 meshes to obtain graphite solid waste powder.

4. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste according to claim 3, wherein the graphite purification tailings are calcined at 400-500 ℃ for 1-3 h.

5. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste according to claim 1, wherein when the slurry is prepared, water is added into the mixed powder until the water content reaches 50-200%, and the mixture is uniformly mixed.

6. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste as the claim 1, wherein the slurry is kept still for 5-8 h.

7. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste according to claim 1, wherein the autoclaving pressure is 0.8-1.2 MPa.

8. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste according to claim 1, wherein the product after the autoclaving treatment is dried until the water content is 7-12%.

9. The method for preparing the soil conditioner by utilizing the graphite high-silicon solid waste as the claim 1, wherein the dried product is scattered to-100 meshes by a dry method.

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