Solid waste multi-component combined activation soil remediation system

Abstract

The present application relates to the technical field of soil treatment, in particular to a soil remediation system for solid waste multi-component joint activation, which comprises a boiler tail gas purification and waste heat cascade utilization unit, a biochar preparation unit, a low-rank coal slime preparation porous carbon unit, a power plant ash alkali metal leaching and residue activation unit, a mixed component composite activation unit and a compound fertilizer forming preparation unit; the boiler tail gas purification and waste heat cascade utilization unit is used for removing dust and acid gas, and the waste heat is used for preparing biochar by biomass pyrolysis and preparing porous carbon by low-rank coal slime; the present application can prepare soil remediation products with water and fertilizer retention and harmlessness by the organic and inorganic compounding of biomass, low-rank coal slime and power plant ash, which has important significance for the treatment and harmless remediation of special soil such as saline-alkali soil and desert soil.

Description

Technical Field

[0001] This invention relates to the field of soil remediation technology, specifically to a soil remediation system for the combined activation of multiple components of solid waste. Background Technology

[0002] Soil improvement involves applying soil conditioners and related technologies to enhance the physical, chemical, and biological properties of soil, making it more suitable for crop growth and promoting nutrient absorption. There are many types of soil conditioners, which can be categorized by function as moisture-retaining agents, sand-fixing agents, water-retaining agents, fertilizer enhancers, pH-lowering agents, and disinfectants, each with its specific effects. In general, soil conditioners effectively alter soil aggregate structure, increase soil porosity, and reduce soil bulk density; improve soil water retention and moisture retention, alleviating drought and water shortage; significantly increase the content of essential nutrients for crop growth, such as N, P, K, organic matter, humus, and humic acids, thus enhancing soil fertility; reduce the content of heavy metals in the soil, mitigating their toxic effects on crops; and improve soil enzyme activity, optimizing the soil microbial community structure, creating an excellent microbial environment for crop growth, thereby significantly increasing crop yield.

[0003] In recent years, the preparation of soil conditioners from fly ash has become a research hotspot and has been widely used for the improvement of saline-alkali land. Although fly ash can improve soil structure, enhance soil fertility, and play an important role in regulating the soil environment, the use of fly ash alone can also lead to the following problems: pure fly ash soil can deteriorate certain soil capacities and characteristics (such as soil water storage capacity and nutrient properties), and the presence of heavy metals in fly ash soil can lead to groundwater or soil pollution. Tailings slime, a high-carbon organic waste, has many difficulties in utilization due to its high viscosity, high water content, and high ash content; its clean and resource-based utilization has become an urgent issue to be addressed in my country. Biomass, as a renewable solid waste, can increase the content of organic matter, humic acid, and other nutrients in the soil, improve soil physical properties, enhance soil biological activity, and increase fertility after appropriate treatment. Therefore, developing a new soil improvement technology using common inorganic minerals and organic waste after harmless disposal is of great significance for resource recycling, soil remediation, ecological environment, and food security. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention proposes a soil remediation system that combines the activation of multiple components of solid waste. This invention enables the utilization of waste heat from flue gas while simultaneously preparing soil remediation products with water retention, fertilizer retention, and harmlessness through a combination of organic and inorganic components such as biomass, low-rank coal slime, and power plant ash. This is of great significance for the treatment and harmless remediation of special soils such as saline-alkali land and desert soil.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a soil remediation system for multi-component joint activation of solid waste, comprising a boiler exhaust gas purification and waste heat cascade utilization unit, a biochar preparation unit, a low-rank coal slime porous carbon preparation unit, a power plant ash alkali metal leaching and residue activation unit, a mixed component composite activation unit, and a compound fertilizer molding and preparation unit.

[0006] The boiler exhaust gas purification and waste heat cascade utilization unit is used to remove dust and acidic gases, and the waste heat is used for biomass pyrolysis to produce biochar and low-rank coal slime to prepare porous carbon, respectively. The biochar preparation unit is used for biomass crushing, then mixing with alkaline leaching solution from power plant ash, and then preparing biochar, liquid phase components, and pyrolysis gas through high-temperature hydrothermal treatment of flue gas. The liquid phase components are separated into small molecule acids and organic matter, and the pyrolysis gas is used for combustion to recover heat energy. The low-rank coal slime porous carbon preparation unit is used for low-rank coal slime deashing, then mixing with alkaline leaching solution from ash, and then heating with waste heat from flue gas in a composite energy field to prepare porous carbon. The power plant ash... The alkali metal leaching and residue activation unit is used to leach K and Na ions from power plant ash and concentrate them for use in assisting the pyrolysis of low-rank coal slime and biomass. The leaching residue is thermally activated and used as inorganic matter for compound activation with other components. The mixed component compound activation unit is used to mix and activate small molecule acids produced by biomass pyrolysis, biochar, porous carbon prepared from low-ash coal slime, and activated ash leaching residue to form a compound fertilizer raw material with synergistic effects of multifunctional components. The compound fertilizer molding and preparation unit is used to achieve uniform mixing of components through multi-stage mixing of the compound fertilizer raw material, and finally to form the product by molding and granulation using a molding machine.

[0007] Preferably, the boiler exhaust gas purification is used to remove sulfides, nitrogen oxides, dust, chlorides, and fluorides from the exhaust gas. The removal methods include nanobubble atomization, catalytic conversion using alkali metal or biochar supported catalysts, and the purification process results in a temperature loss of no more than 10% in the flue gas.

[0008] Preferably, the power plant ash includes coal ash, coal or biomass co-combustion ash, biomass power plant ash, and waste-to-energy incineration ash after the removal of harmful substances; the leaching process is to leach potassium and sodium ions contained in the ash, and the leaching methods are grinding, microwave, low-temperature plasma, forced mechanical stirring, pressure leaching, hydrothermal leaching, and ultrasonic action; which includes three or more methods coupled together, and the leaching efficiency is ≥96%.

[0009] Preferably, the biomass includes various crop straws, poultry and livestock manure, domestic sewage sludge after removing heavy metals and harmful microorganisms, kitchen waste, aquaculture sludge, and river sludge, which are compounded with two or more substances as biomass raw materials.

[0010] Preferably, the biomass pyrolysis is carried out by hydrothermal method, in which biomass is mixed with alkaline solution obtained by leaching and concentrating ash residue for pyrolysis. During pyrolysis, the solid mass of biomass accounts for 15-30% of the total mass, and the alkaline solution exists in the form of K and Na with a concentration ≥2000mg / L. The amount added is 0.2-0.5 times the mass of alkali metals as the total solid mass.

[0011] Preferably, the biomass pyrolysis temperature is 300-480 degrees Celsius to ensure high yield and well-developed pores of pyrolysis biochar, while simultaneously increasing the yield of acid in the pyrolysis liquid phase. The pyrolysis gas is used as an energy combustion supplement for the thermal activation process of the ash leaching residue.

[0012] Preferably, the low-rank coal slime deashing method includes flotation, hydrocyclone separation, spiral separation, hydrothermal deashing, magnetic separation, mild acid leaching, and a combination of one or more methods, to obtain low-ash coal slime with ash content ≤15% after deashing.

[0013] Preferably, the preparation of porous carbon from low-ash coal slime uses purified flue gas steam and rich alkali solution as activation media. The steam temperature is 700-850℃ and the steam flow rate is 0.3-0.8 mL / min. The rich alkali solution exists in the form of K and Na with a concentration ≥2500 mg / L. The amount added is 0.3-0.6 times the mass of alkali metals relative to the total mass of fixed carbon. During the pyrolysis process, microwave irradiation, ultrasonic pore expansion, and multi-stage spiral stirring are used simultaneously to form a composite energy field to prepare high-quality porous carbon.

[0014] Preferably, the liquid component produced by the biomass pyrolysis includes water-soluble small molecule acids and viscous bio-oil. The water-soluble small molecule acids are used to achieve composite activation together with biochar, porous carbon, and activated leaching residue. The activation process includes acid activation and salt activation between biochar, porous carbon, iron, aluminum, silicon, and small molecule acids in the leaching residue, resulting in hydration and enhancing the surface reactivity of inorganic materials. This achieves stable adsorption and conversion of heavy metals. At the same time, the combination of chemical activation, thermal activation, and mechanical activation processes increases the adsorption sites of biochar and activated carbon, effectively enhancing the adsorption of heavy metal ions and salt ions.

[0015] Preferably, after the composite activation, all components need to undergo two or more mixing processes to achieve uniform distribution of each component. The binder required in the material forming process is composed of inorganic binder components of kaolin and bentonite generated by ash activation, sodium humate generated after multi-stage activation of low-rank coal slime, and bio-oil generated by liquid phase separation from biomass pyrolysis, to achieve efficient bonding of the composite binder. After bonding, the material is formed and prepared to obtain granular soil remediation material.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. This invention achieves a leaching efficiency of over 95% for valuable ions such as K, Na, Zn, and Ca in power plant ash slag. After concentration, the inorganic salt ion solution can not only be used as a highly efficient pore-expanding medium in the preparation of biochar and porous carbon, but also be used to formulate compound soil remediation agents through pH adjustment.

[0018] 2. This invention uses coal slime deashing technology to efficiently remove ash from low-rank coal slime that is high in ash and easily mud-like, thus preparing porous carbon with strong adsorption and good water retention from low-rank coal with high moisture content and well-developed pores and fissures. At the same time, after composite activation, it can also effectively release humic acid, achieving multiple improvements to the soil.

[0019] 3. This invention utilizes high-temperature flue gas as a heat source for the preparation of biochar and porous carbon from low-rank coal. For biomass, low-temperature hydrothermal (300-480℃) pyrolysis is used to achieve efficient separation of the gas, liquid, and solid phases. For low-rank coal, high-temperature steam (700-850℃) pyrolysis is used to prepare coal-based porous carbon. A segmented temperature control method is adopted to optimize energy utilization efficiency.

[0020] 4. This invention achieves efficient energy recovery by realizing multi-stage utilization of flue gas heat, effectively separates biomass into three phases (gas, liquid, and solid) for efficient component utilization and energy recovery, achieves efficient separation of low-rank coal slime into micro-minerals, and separates and utilizes power plant ash residue through leaching solution and leaching residue. The entire process is free of secondary pollution, and each component is utilized efficiently, achieving the goal of solid waste disposal without generating secondary solid waste.

[0021] 5. This invention uses biochar, coal-based porous carbon, and activated leaching residue as the core components of a soil remediation agent. It has multiple effects such as passivation of heavy metals, water and fertilizer retention, and slow release of valuable components (salt ions, humic acid, and organic carbon). It is non-toxic and harmless to the soil and can achieve long-term soil treatment, remediation, and improvement. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a comparison table of the leaching efficiency of valuable ions in ash residue in this invention;

[0024] Figure 2 This invention relates to the microstructure and organic matter analysis of cow dung.

[0025] Figure 3 This invention relates to the deashing effect of coal slime and the analysis of organic matter.

[0026] Figure 4 This is a system diagram of the present invention; Detailed Implementation

[0027] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0028] like Figures 1 to 4 As shown, the soil remediation system for multi-component joint activation of solid waste according to the present invention includes a boiler exhaust gas purification and waste heat cascade utilization unit, a biochar preparation unit, a low-rank coal slime porous carbon preparation unit, a power plant ash alkali metal leaching and residue activation unit, a mixed component composite activation unit, and a compound fertilizer molding and preparation unit.

[0029] The boiler exhaust gas purification and waste heat cascade utilization unit is used to remove dust and acidic gases, and the waste heat is used for biomass pyrolysis to produce biochar and low-rank coal slime to prepare porous carbon, respectively. The biochar preparation unit is used for biomass crushing, then mixing with alkaline leaching solution from power plant ash, and then preparing biochar, liquid phase components, and pyrolysis gas through high-temperature hydrothermal treatment of flue gas. The liquid phase components are separated into small molecule acids and organic matter, and the pyrolysis gas is used for combustion to recover heat energy. The low-rank coal slime porous carbon preparation unit is used for low-rank coal slime deashing, then mixing with alkaline leaching solution from ash, and then heating with waste heat from flue gas in a composite energy field to prepare porous carbon. The power plant ash... The alkali metal leaching and residue activation unit is used to leach K and Na ions from power plant ash and concentrate them for use in assisting the pyrolysis of low-rank coal slime and biomass. The leaching residue is thermally activated and used as inorganic matter for compound activation with other components. The mixed component compound activation unit is used to mix and activate small molecule acids produced by biomass pyrolysis, biochar, porous carbon prepared from low-ash coal slime, and activated ash leaching residue to form a compound fertilizer raw material with synergistic effects of multifunctional components. The compound fertilizer molding and preparation unit is used to achieve uniform mixing of components through multi-stage mixing of the compound fertilizer raw material, and finally to form the product by molding and granulation using a molding machine.

[0030] As one embodiment of the present invention, the boiler exhaust gas purification is used to remove sulfides, nitrogen oxides, dust, chlorides and fluorides from the exhaust gas. The removal methods include nanobubble atomization, catalytic conversion with alkali metal or biochar supported catalysts, and the purification process results in a temperature loss of no more than 10% in the flue gas.

[0031] As one embodiment of the present invention, the power plant ash includes coal ash, coal or biomass co-combustion ash, biomass power plant ash, and waste-to-energy incineration ash after the removal of harmful substances; the leaching process is to leach potassium and sodium ions contained in the ash, and the leaching methods are grinding, microwave, low-temperature plasma, forced mechanical stirring, pressure leaching, hydrothermal leaching, and ultrasonic action; which includes three or more methods coupled together, and the leaching efficiency is ≥96%.

[0032] In one embodiment of the present invention, the biomass includes various crop straws, poultry and livestock manure, domestic sewage sludge after removing heavy metals and harmful microorganisms, kitchen waste, aquaculture sludge, and river sludge, which are compounded with two or more substances as biomass raw materials.

[0033] In one embodiment of the present invention, the biomass pyrolysis is carried out by hydrothermal method. Biomass is mixed with alkaline solution obtained by leaching and concentrating ash residue for pyrolysis. During pyrolysis, the solid mass of biomass accounts for 15-30% of the total mass. The alkaline solution is present in the form of K and Na with a concentration ≥2000mg / L. The amount added is 0.2-0.5 times the mass of alkali metals as the total solid mass.

[0034] In one embodiment of the present invention, the biomass pyrolysis temperature is 300-480 degrees Celsius, which ensures high yield and well-developed pores of pyrolysis biochar, while increasing the yield of acid in the pyrolysis liquid phase. The pyrolysis gas is used as an energy combustion supplement for the thermal activation process of ash leaching residue.

[0035] As one embodiment of the present invention, the low-rank coal slime deashing method includes flotation, hydrocyclone separation, spiral separation, hydrothermal deashing, magnetic separation, mild acid leaching, and a combination of one or more methods, and a low-ash coal slime with ash content ≤15% is obtained after deashing.

[0036] In one embodiment of the present invention, the preparation of porous carbon from low-ash coal slime uses purified flue gas steam and alkali-rich solution as activation media. The steam temperature is 700-850℃ and the steam flow rate is 0.3-0.8 mL / min. The alkali-rich solution exists in the form of K and Na with a concentration ≥2500 mg / L. The amount added is 0.3-0.6 times the mass of alkali metals relative to the total mass of fixed carbon. During the pyrolysis process, microwave irradiation, ultrasonic pore expansion, and multi-stage spiral stirring are simultaneously used to form a composite energy field to prepare high-quality porous carbon.

[0037] In one embodiment of the present invention, the liquid component produced by biomass pyrolysis includes water-soluble small molecule acids and viscous bio-oil. The water-soluble small molecule acids are used to achieve composite activation together with biochar, porous carbon, and activated leaching residue. The activation process includes acid activation and salt activation between biochar, porous carbon, iron, aluminum, silicon, and small molecule acids in the leaching residue, resulting in hydration and enhancing the surface reactivity of inorganic materials. This achieves stable adsorption and conversion of heavy metals. At the same time, the combination of chemical activation, thermal activation, and mechanical activation processes increases the adsorption sites of biochar and activated carbon, effectively enhancing the adsorption of heavy metal ions and salt ions.

[0038] As one embodiment of the present invention, after the composite activation, all components need to undergo two or more mixing processes to achieve uniform distribution of each component. The binder required in the material forming process is composed of inorganic binder components of kaolin and bentonite generated by ash slag activation, sodium humate generated after multi-stage activation of low-rank coal slime, and bio-oil generated by liquid phase separation from biomass pyrolysis, to achieve efficient bonding of the composite binder. After bonding, the material is formed and prepared to obtain granular soil remediation material.

[0039] The team behind this invention has been focusing on the research and practical application of technologies for the co-processing and resource utilization of coal-based solid waste (coal gangue, fly ash, coal slime, etc.) and agricultural solid waste (straw, livestock manure, sludge, etc.). Currently, significant results have been achieved in areas such as the utilization of thermal conversion flue gas energy, separation of valuable mineral components, and preparation of porous carbon materials. Based on existing achievements, this invention is applicable to the industrial application of soil remediation technologies and products.

[0040] The flue gas from the coal mine pithead power plant provides the heat source. The flue gas temperature is 600℃. After the flue gas passes through an iron-based catalytic liquid and a micro-nano bubble generator to atomize and remove most of the dust, acidic gases (SOx, NOx, HF, etc.) and O2, the temperature is maintained at 550℃ for the pyrolysis of biomass and low-ash coal slime.

[0041] Furthermore, fly ash and slag from the pithead power plant are leached and activated together. After grinding the ore into a high-concentration slurry using a ball mill, valuable ions such as K and Na are leached through ultrasonic cavitation, forced mechanical stirring, and pressure leaching, with a leaching efficiency of ≥96%.

[0042] Furthermore, biomass straw and poultry and livestock manure were selected as biomass, mixed in a 6:4 ratio, and then pyrolyzed at a temperature of 380℃. The composite alkaline solution was prepared with a concentration of 2200 mg / L of leached K+ and Na+, and the mass of alkaline ions was added at 0.2 times the total mass of biomass. The solid mass was 25% of the total solid-liquid mass. The pyrolysis produced three components: biochar, pyrolysis gas, and pyrolysis oil. The pyrolysis gas was introduced into the thermal activation stage of the ash residue leaching residue to provide heat for combustion. The liquid phase components were mainly small molecule acids and bio-oil. The small molecule acids were used for the joint activation of the mixture, and the acidic macromolecular bio-oil was used for binding in the molding stage of the mixture.

[0043] Furthermore, low-rank coal slime produced at the coal mine pithead is selected as raw material. After a grinding process, the mineral particles and coal particles are separated. Through forced slurry conditioning, the clay minerals are further separated on the coal surface and the components are separated. After slurry conditioning, the slurry is passed through a hydrocyclone to remove ash, and the ash content of the coal slime is reduced to below 15%. The deashed low-rank coal slime is used as an activation medium to prepare porous carbon, which simultaneously releases humic acid. The steam temperature is 750℃, generated by secondary heating of the flue gas, and the steam flow rate is 0.5mL / min. The alkali-rich solution exists in the form of K and Na, with a concentration of 2800mg / L. The amount added is 0.5 times the mass of alkali metals and the total mass of fixed carbon. During the pyrolysis process, microwave continuous flow and ultrasonic cavitation enhancement composite energy field are used to prepare high-quality porous carbon.

[0044] Furthermore, the water-soluble small molecule acid, biochar, porous carbon, and activated leaching residue in the biomass pyrolysis solution are mixed together and activated by synergistic grinding machinery, two-stage stirring and mixing, and mild acid chemical activation. Then, it is mixed again with the oil produced by biomass pyrolysis. The mixture contains 20% biochar, 25% porous coal carbon, 30% leaching residue, 5% bio-pyrolysis oil, and 20% small molecule acid solution. The pH value of the mixed material is guaranteed to be no higher than 6. After being granulated into 2-5mm particles, it is used as a soil remediation agent for saline-alkali land.

[0045] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the appendix. Figure 3 The orientations or positional relationships shown are for the convenience of describing the present invention and simplifying the description only, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and should not be construed as indicating or implying relative importance.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A soil remediation system for multi-component co-activation of solid waste, characterized in that: It includes a boiler exhaust gas purification and waste heat cascade utilization unit, a biochar preparation unit, a low-rank coal slime preparation porous carbon unit, a power plant ash slag alkali metal leaching and residue activation unit, a mixed component composite activation unit, and a compound fertilizer molding and preparation unit. The boiler exhaust gas purification and waste heat cascade utilization unit is used to remove dust and acidic gases, and the waste heat is used for biomass pyrolysis to produce biochar and low-rank coal slime to prepare porous carbon, respectively. The biochar preparation unit is used for biomass crushing, then mixing with alkaline leaching solution from power plant ash, and then preparing biochar, liquid phase components, and pyrolysis gas through high-temperature hydrothermal treatment of flue gas. The liquid phase components are separated into small molecule acids and organic matter, and the pyrolysis gas is used for combustion to recover heat energy. The low-rank coal slime porous carbon preparation unit is used for low-rank coal slime deashing, then mixing with alkaline leaching solution from ash, and then heating with waste heat from flue gas in a composite energy field to prepare porous carbon. The power plant ash... The alkali metal leaching and residue activation unit is used to leach K and Na ions from power plant ash and concentrate them for use in assisting the pyrolysis of low-rank coal slime and biomass. The leaching residue is thermally activated and used as inorganic matter for compound activation with other components. The mixed component compound activation unit is used to mix and activate small molecule acids produced by biomass pyrolysis, biochar, porous carbon prepared from low-ash coal slime, and activated ash leaching residue to form a compound fertilizer raw material with synergistic effects of multifunctional components. The compound fertilizer molding and preparation unit is used to achieve uniform mixing of components through multi-stage mixing of the compound fertilizer raw material, and finally to form the product by molding and granulation using a molding machine.

2. The soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The boiler exhaust gas purification is used to remove sulfides, nitrogen oxides, dust, chlorides, and fluorides from the exhaust gas. The removal methods include nanobubble atomization and catalytic conversion using alkali metal or biochar supported catalysts. The purification process results in a temperature loss of no more than 10% in the flue gas.

3. The soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The power plant ash residue includes coal ash residue, coal co-combustion ash residue, biomass co-combustion ash residue, biomass power plant ash residue, and waste-to-energy plant incineration ash residue after the removal of harmful substances; the leaching process is to leach potassium and sodium ions contained in the ash residue, and the leaching methods are grinding, microwave, low-temperature plasma, forced mechanical stirring, pressure leaching, hydrothermal leaching, and ultrasonic action; which includes three or more methods coupled together, with a leaching efficiency ≥96%.

4. The soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The biomass includes various crop straws, poultry and livestock manure, domestic sewage sludge after removing heavy metals and harmful microorganisms, kitchen waste, aquaculture sludge, and river sludge, which are compounded with two or more substances as biomass raw materials.

5. The soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The biomass pyrolysis is carried out using a hydrothermal method. Biomass is mixed with alkaline solution obtained from ash leaching and concentration for pyrolysis. During pyrolysis, the solid mass of biomass accounts for 15-30% of the total mass. The alkaline solution is in the form of K and Na, with a concentration ≥2000 mg / L. The amount of alkali metal added is 0.2-0.5 times the mass of the solid metal.

6. The soil remediation system for multi-component co-activation of solid waste according to claim 5, characterized in that: The biomass pyrolysis temperature is 300-480 degrees Celsius, which ensures high yield and well-developed pores of pyrolysis biochar, while also increasing the yield of acid in the pyrolysis liquid phase. The pyrolysis gas is used as an energy source to supplement the thermal activation process of the ash leaching residue.

7. The soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The deashing methods for low-rank coal slime include flotation, hydrocyclone separation, spiral separation, hydrothermal deashing, magnetic separation, mild acid leaching, and combinations of one or more methods, resulting in low-ash coal slime with an ash content of ≤15%.

8. The soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The preparation of porous carbon from low-ash coal slime uses purified flue gas steam and rich alkali solution as activation media. The steam temperature is 700-850℃ and the steam flow rate is 0.3-0.8 mL / min. The rich alkali solution exists in the form of K and Na with a concentration ≥2500 mg / L. The amount added is 0.3-0.6 times the mass of alkali metals and the total mass of fixed carbon. During the pyrolysis process, microwave irradiation, ultrasonic pore expansion, and multi-stage spiral stirring are used simultaneously to form a composite energy field to prepare high-quality porous carbon.

9. A soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: The liquid components produced by the biomass pyrolysis include water-soluble small-molecule acids and viscous bio-oil. The water-soluble small-molecule acids are used to achieve composite activation together with biochar, porous carbon, and activated leaching residue. The activation process includes acid activation and salt activation between biochar, porous carbon, iron, aluminum, silicon, and small-molecule acids in the leaching residue, resulting in hydration and enhancing the surface reactivity of inorganic materials. This achieves stable adsorption and conversion of heavy metals. At the same time, the combination of chemical activation, thermal activation, and mechanical activation processes increases the adsorption sites of biochar and activated carbon, effectively enhancing the adsorption of heavy metal ions and salt ions.

10. A soil remediation system for multi-component co-activation of solid waste according to claim 1, characterized in that: After the composite activation, all components need to undergo two or more mixing processes to achieve uniform distribution of each component. The binder required in the material forming process consists of inorganic binder components of kaolin and bentonite generated by ash activation, sodium humate generated after multi-stage activation of low-rank coal slime, and bio-oil generated by liquid phase separation from biomass pyrolysis, to achieve efficient bonding of the composite binder. After bonding, the material is formed and prepared to obtain granular soil remediation material.

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