阅读说明：本技术 一种利用石墨高硅固废制备土壤改良剂的方法 (Method for preparing soil conditioner by utilizing graphite high-silicon solid waste ) 是由 任子杰 王康 高惠民 张凌燕 邱杨率 于 2020-06-02 设计创作，主要内容包括：本发明公开了一种利用石墨高硅固废制备土壤改良剂的方法,包括如下步骤：(1)将石墨固体废弃物磨矿,得到石墨固废粉末,再将石墨固废粉末和活化剂混合均匀,得到混合粉料,石墨固废粉末和活化剂的质量比为55～80：20～45,活化剂包括如下重量份的组分：石灰89～96份、硫酸钠1～3份、碳酸钠1～3份、氢氧化钾1～3份和氧化铝1～2份；(2)向混合粉料中加水混合均匀,得到浆料,将浆料静置养护后进行蒸压处理,蒸压温度为140～190℃,蒸压时间为8～16h,对蒸压处理后的产物进行干燥和研磨,得到土壤改良剂。本发明实现了石墨固体废弃物的资源化利用,且制得的土壤改良剂提高了土壤保肥、保水能力。(The invention discloses a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, which comprises the following steps: (1) 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; (2) adding water into the mixed powder, uniformly mixing to obtain slurry, standing and curing the slurry, then carrying out steam-pressing treatment, wherein the steam-pressing temperature is 140-190 ℃, the steam-pressing time is 8-16 h, and drying and grinding the product after the steam-pressing treatment to obtain the soil conditioner. The invention realizes the resource utilization of the graphite solid waste, and the prepared soil conditioner improves the soil fertilizer and water retention capacity.)

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.

Technical Field

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

Background

Graphite is an important nonmetallic mineral material with multiple characteristics of high electrical conductivity, high thermal conductivity, acid and alkali corrosion resistance, lubrication and the like, and is widely applied to various industrial fields. In recent years, with the rapid development of industrial technologies in China, the demand of graphite is increasing day by day. The graphite ore can generate a large amount of waste rocks in the mining process and a large amount of tailings in the purification process, and the graphite solid waste causes environmental hazards such as land occupation, water body pollution, soil pollution and the like and has great potential safety hazards of dam break. According to statistics, about 20 tons of graphite tailings need to be discharged on average when 1 ton of graphite products are produced, more than 100 large and small graphite tailing ponds are used in China, the average service life is only 5 years, and the tailing ponds form great threats to the safety of mining areas. The resource utilization of graphite solid waste is one of the main approaches to solve the problems.

As a big agricultural country, land resources are not optimistic, on one hand, the urbanization development occupies a large amount of excellent cultivated land and the industrial development makes the soil pollution more serious, thereby causing the heavy metal content in the soil to be increased and causing great threat to the health of human bodies. On the other hand, the water and soil loss is continuously aggravated to cause land degradation which is no longer suitable for the growth of crops, and unreasonable farming and continuous cropping of people and excessive use of chemical fertilizers and pesticides cause increasingly serious soil degradation, soil fertility is reduced, and productivity is reduced. The development of soil conditioners is promoted by the increasing severity of the soil problems, the use of the soil conditioners has an obvious effect on soil improvement, but most of the current soil conditioners have high cost, large dosage and single effect, and cannot be popularized in a large area.

Therefore, the research and development of the soil conditioner which has low cost and multiple functions and can recycle the graphite solid waste have great significance for solving the problems of the graphite solid waste and improving the soil.

Disclosure of Invention

The invention aims to overcome the technical defects and provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste.

In order to achieve the technical purpose, the technical scheme of the invention provides a method for preparing a soil conditioner by utilizing graphite high-silicon solid waste, which comprises 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.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, graphite solid waste is used as a main raw material, and an activating agent prepared from lime, sodium sulfate, sodium carbonate, potassium hydroxide and aluminum oxide according to a certain proportion is added, after the graphite solid waste powder and the activating agent are autoclaved, silicate such as calcium silicate, sodium silicate and potassium silicate and a zeolite phase are obtained, and the obtained silicate not only remarkably improves the conversion rate of effective silicon, provides abundant silicon elements for plants, but also provides abundant potassium, sodium and other various nutrient elements for the plants;

2. the main component of the soil conditioner obtained by autoclaving is calcium silicate, which has the characteristics of strong adsorbability, low specific gravity and more pores, and can adsorb elements and water needed by vegetation in soil, prevent the loss of the elements and water needed by vegetation, improve the soil fertilizer retention and water retention capacity, adsorb heavy metal ions in soil, prevent the migration of the heavy metal ions and further reduce the bioactivity of the heavy metal ions; in addition, the obtained sodium silicate and potassium silicate are soluble silicates, the calcium silicate is insoluble silicates, the soluble silicates act on soil and can immediately release effective elements in the soil, the calcium silicate and zeolite phases have more pores and slowly release the elements required by vegetation after adsorbing the elements, and the soluble silicates and the insoluble silicates with more pores and strong adsorbability are matched with the zeolite phases, so that the action time of nutrient elements is prolonged, and the utilization rate of the fertilizer is improved;

3. the zeolite phase contained in the soil conditioner obtained by the steam-pressure treatment also has the characteristics of strong adsorbability, low specific gravity and more pores, and can further improve the soil fertilizer retention and water retention capacity and reduce the biological activity of heavy metal ions in the soil under the combined action of the zeolite phase and calcium silicate;

4. the waste graphite solid waste is used as a main raw material and is prepared into the soil conditioner, so that the problems that the graphite solid waste is accumulated to occupy land and cause harm to the environment can be solved, the resource utilization of the graphite solid waste is realized, and the preparation method provided by the invention is simple to operate, mild in reaction conditions, low in raw material cost and suitable for industrial mass production and application.

Drawings

FIG. 1 is a process flow chart for preparing a soil conditioner by using graphite high-silicon solid waste according to an embodiment of the invention;

fig. 2 is a process flow chart for preparing graphite solid waste powder according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Fig. 1 is a process flow diagram for preparing a soil conditioner from graphite high-silicon solid waste, which is provided in an embodiment of the present invention, and as shown in fig. 1, the embodiment of the present invention provides a method for preparing a soil conditioner from graphite high-silicon solid waste, which includes the following steps:

(1) 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;

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

The method for preparing the soil conditioner by using the graphite high-silicon solid waste provided by the embodiment of the invention comprises the steps of grinding the graphite solid waste to obtain graphite solid waste powder, uniformly mixing the graphite solid waste powder with an activating agent containing lime, sodium sulfate, sodium carbonate, potassium hydroxide and aluminum oxide to prepare slurry, then carrying out still pressing treatment at a certain temperature after standing and maintaining, wherein in the process of still pressing treatment, SiO in the graphite solid waste powder₂Hydrothermal reaction with lime to produce calcium silicate and SiO₂Respectively react with sodium sulfate, sodium carbonate and potassium hydroxide to generate sodium silicate, potassium silicate and SiO₂The active agent reacts with aluminum oxide to generate a zeolite phase, and silicate phases and zeolite phases with different amounts are prepared by controlling the using amounts of lime, sodium sulfate, sodium carbonate, potassium hydroxide and aluminum oxide in the active agent, wherein the sodium silicate and the potassium silicate are soluble silicates, so that the conversion rate of effective silicon can be improved, rich silicon elements can be provided for plants, various nutrient elements such as potassium and sodium can be provided, and the soluble silicates can release the nutrient elements immediately after acting on soil; the calcium silicate and the zeolite are not easy to dissolve, but have strong adsorbability, low specific gravity and more pores, and can adsorb and store nutrient elements in the fertilizerThe fertilizer is slowly released into soil, and the soluble silicate, the insoluble silicate and the zeolite are matched to increase the action time of nutrient elements and improve the utilization rate of the fertilizer. In addition, the insoluble calcium silicate and zeolite phases have the characteristics of strong adsorbability, low specific gravity and more pores, so that the insoluble calcium silicate and zeolite phases can adsorb elements and moisture required by vegetation in soil, prevent the loss of the elements and moisture required by the vegetation, improve the fertilizer retention and water retention capacity of the soil, adsorb heavy metal ions in the soil, prevent the migration of the heavy metal ions and further reduce the bioactivity of the heavy metal ions. According to the method for preparing the soil conditioner by using the graphite high-silicon solid waste, provided by the embodiment of the invention, the graphite solid waste powder and an activating agent containing lime, sodium sulfate, sodium carbonate, potassium hydroxide and aluminum oxide are uniformly mixed to prepare slurry, and then the slurry is subjected to still pressure treatment at a certain temperature after standing and maintaining to prepare the soil conditioner.

In some preferred embodiments of the present invention, the graphite solid waste is waste rock from graphite mining or graphite purification tailings, and the SiO of the graphite solid waste₂The content is higher than 40%.

Fig. 2 is a process flow diagram for preparing graphite solid waste powder according to an embodiment of the present invention, and as shown in fig. 2, if the graphite solid waste in step (1) of the embodiment of the present invention is waste rock generated by exploiting graphite, the graphite solid waste is firstly crushed and then ground to below 200 meshes to obtain graphite solid waste powder; if the graphite solid waste in the step (1) of the embodiment of the invention is graphite purification tailings, the graphite purification tailings are calcined, and then ground to below 200 meshes to obtain graphite solid waste powder.

In some preferred embodiments of the present invention, the graphite purification tailings are calcined at 400-500 ℃ for 1-3 h to remove the organic solvent in the graphite purification tailings and prevent the organic solvent from entering the soil.

In some preferred embodiments of the invention, when the slurry is prepared in the step (2), water is added into the mixed powder until the water content reaches 50-200%, and the mixture is uniformly mixed; the water content of the slurry is optimized to ensure that the calcium oxide and the silicon dioxide in the graphite solid waste powder are better subjected to hydration reaction.

In some preferred embodiments of the invention, the slurry in the step (2) is kept still for 5-8 hours to ensure that the activating agent fully activates the graphite solid waste powder.

In some preferred embodiments of the invention, the autoclaving pressure is 0.8 to 1.2 MPa; so as to promote the silicon dioxide in the graphite solid waste powder to fully react with the activating agent to generate the required silicate phase and zeolite phase.

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

In some preferred embodiments of the invention, the dried product is broken up to-100 mesh using a dry process; so as to ensure that the prepared soil conditioner has larger specific surface area.

When the soil conditioner prepared by the invention is used, 3%, 5% or 10% of the soil can be added, and the soil conditioner can be added by a person skilled in the art according to actual needs, and the dosage of the soil conditioner is not further limited by the invention.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The experimental methods in the present invention are conventional methods unless otherwise specified. The experimental materials used in the invention are all purchased in the market if no special description is provided; SiO in waste rock from graphite mining used in the following examples₂68.3 percent of SiO in the graphite purification tailings₂The content is 74.9%, the CaO content in the used lime powder is 70%, the content of the used sodium sulfate is more than or equal to 99%, the content of the used sodium carbonate is more than or equal to 99%, the content of the used potassium hydroxide is more than or equal to 99%, and the used oxygenThe aluminum content is more than or equal to 99 percent.