992 results about "Red mud" patented technology

The invention relates to a high-performance solid-waste-based offshore wind power grouting material and a preparation method thereof, and a solid-waste-based cementing material is a hydraulic cementing material prepared by processing and grinding one or more solid wastes such as water-quenched blast furnace slag, steel slag, desulfurized gypsum, fly ash, red mud, tailings, carbide slag and phosphogypsum as raw materials according to a certain proportion. The solid waste-based cementing material is adopted to replace 525 Portland cement, the prepared grouting material product is excellent in performance, the carbon emission of the grouting material product is remarkably reduced, the cost is also reduced, resource utilization of industrial solid waste is facilitated, meanwhile, the performance of the grouting material is obviously improved, and the grouting material is suitable for popularization and application. The advantages of ultrahigh strength, elasticity modulus, high flowability, low shrinkage and high durability are realized.

The present invention belongs to the field of resource utilization of building materials and solid waste, and relates to a red-mud-based cementing material based on efficient drying, component homogenization and activity improvement, and a preparation method therefor. The preparation method comprises: adding a filter aid to red mud to carry out sedimentation, then subjecting same to filter pressing until the water content is 14-16%, then drying the solid material, which has been subjected to filter pressing, until the water content is 4% or below, and finally grinding same to obtain the product. The filter aid comprises the following raw materials: 10-30 parts of polyaluminum chloride, 5-15 parts of polyaluminum sulfate, 1000-1200 parts of blast furnace slag or fly ash, 700-900 parts of steel slag, 400-600 parts of carbide slag or alkaline residues, and 300-400 parts of desulfurized gypsum or phosphogypsum or fluorgypsum. By means of the present invention, the dehydration efficiency of red mud can be improved, the red-mud-based cementing material can also be prepared in one step; the preparation process for the red-mud-based cementing material is simplified; and the prepared red-mud-based cementing material has the advantages of a high mechanical strength, high durability and erosion resistance.

The invention discloses a cementing material for a solid waste-based road of a coal-fired power plant and a preparation method of the cementing material. The cementing material mainly comprises a cementing component, an alkali-activated component and a reinforcing component, the gelling component is a mixture of coal-fired power plant fly ash and furnace slag; the alkali-activated component is a mixture of alkali residues, red mud, blast furnace slag and coal-fired power plant desulfurized gypsum; the reinforcing component is rice hull ash or peanut hull ash. The mass ratio of the gelling component to the alkali-activated component is (4 / 1)-(10 / 1); and the addition amount of the reinforcing component is 1-3% of that of the main body material. The coal-fired power plant solid waste fly ash, the furnace slag and the desulfurized gypsum are used as main bodies, a small amount of other industrial solid waste is added, and the cementing material belongs to a full-solid-waste low-carbon cementing material and can be applied to a road base, a subbase or a base layer. The invention has the characteristics of low carbon emission, high solid waste consumption, simple production process and strong pavement performance, and in addition, the invention has a good stabilization effect on the problem that part of solid waste heavy metals and sulfate ions in a coal-fired power plant exceed the standard.

The invention relates to the technical field of cement materials, in particular to a red-mud-containing steel slag composite cementing material and a preparation method thereof.The method comprises the steps that red mud, slag, steel slag, desulfurized gypsum and sulphoaluminate cement clinker are subjected to dry mixing to obtain an initial mixture; determining whether the excitation capability of the potential hydration activity reaches the standard or not based on the alkaline matching index, and adjusting the weight part of the sulphoaluminate cement clinker; adding a composite exciting agent to obtain activated slurry; determining whether the dispersion effect of the flocculation structure of the initial mixture is qualified or not based on the dispersion index of the flocculation structure, and adjusting the ball milling rotating speed; adding a polymer emulsion to obtain an initial composite cementing material; determining whether the synergistic enhancement effect of the polymer emulsion and the activated slurry is qualified or not based on the synergistic enhancement index, and adjusting the dripping rate of the polymer emulsion; the steel slag composite cementing material containing the red mud is obtained. The preparation stability of the red mud-containing steel slag composite cementing material is improved.

The invention discloses a method for preparing a bismuth ferrite composite catalytic material by using red mud as well as a product and application of the bismuth ferrite composite catalytic material. The method comprises the following steps: mixing chlorine salt and red mud, uniformly stirring, adding a hydrochloric acid solution, uniformly stirring, roasting, recovering flue gas generated in the roasting process, and obtaining roasting residues and roasting dust generated by recovering the flue gas after roasting is finished; and mixing the roasted dust and bismuth nitrate, uniformly stirring, adding the calcined residue, uniformly grinding, adding water, stirring, drying the material, and calcining to obtain the bismuth ferrite composite catalytic material. The preparation process is simple, the red mud is used as a main raw material, and full-amount resource utilization of the red mud can be achieved. The prepared composite catalytic material can be used for efficiently purifying landfill leachate, and COD, ammonia nitrogen, total phosphorus and heavy metal pollution are efficiently removed through a photocatalysis mechanism.

The invention discloses a road cementing material based on bulk solid wastes and a preparation method thereof, and belongs to the field of geopolymer cementing materials. The material is prepared from 35-38 parts of fly ash, 15-18 parts of acid-washed red mud, 22-25 parts of carbide slag, 20-23 parts of phosphogypsum, 5-8 parts of rice hull ash, 6-9 parts of a water reducing agent and water, and the water-binder ratio is (0.4-0.5): 1. Wherein the pickling red mud is treated by 5-6% dilute sulphuric acid (pH is 8-9, and heavy metal is reduced by 30%), and the rice hull ash (SiO2 is greater than or equal to 85%) and the nano silicon dioxide (10-30nm) synergistically optimize the microstructure. The 28-day compressive strength of the material is larger than or equal to 35 MPa, the load cycle strength loss rate is smaller than or equal to 5%, the CO2 emission amount is 62 kg / t, the heavy metal leaching concentration is lower than the national standard by 50%, and the cost is only 31.6% of that of traditional cement. According to the invention, efficient synergistic utilization of four solid wastes of fly ash, red mud, carbide slag and ardealite is realized, and the concrete has the characteristics of high strength, low pollution, salt corrosion resistance and the like, is suitable for heavy-duty road base and severe cold area engineering, and has remarkable environmental protection and economic values.

The invention discloses a method for preparing a composite catalyst by synergistically utilizing red mud and arsenic alkali residues as well as a product and application thereof, and belongs to the field of resource utilization of industrial wastes. The method disclosed by the invention is simple in preparation process, wide in preparation raw material source and capable of realizing full-amount utilization of the red mud and the arsenic alkali residues. Compared with a traditional titanium dioxide and iron arsenate catalyst, the composite catalyst prepared by the method is more excellent in performance, the landfill leachate treatment efficiency can be remarkably improved, and the catalytic removal effect of 2145 mg / g COD, 162 mg / g total phosphorus, 356 mg / g ammonia nitrogen and 122 mg / g mercury can be achieved at most.

The invention belongs to the technical field of solid waste utilization, and discloses a low-cost mine filling material and a preparation method thereof. The low-cost mine filling material comprises the following raw materials in parts by mass: 100 parts of red mud, 15-25 parts of an acid activator, 4-10 parts of fly ash, 4-10 parts of coal gangue, 5-12 parts of basalt fiber waste silk, 1-8 parts of a waste molecular sieve-based self-repairing material and 70-100 parts of water. Various industrial solid wastes such as the red mud, the ardealite, the fly ash, the coal gangue, the basalt fiber waste filaments and the waste silicon-aluminum molecular sieves are adopted, so that the source of the mine filling material can be effectively expanded, the cost is low, the environmental pressure caused by waste stacking is reduced, and good economic and environmental benefits are generated.

The invention discloses a preparation method of a green high-performance industrial solid waste-based grouting material, and belongs to the field of industrial solid waste treatment and grouting reinforcement, and the preparation method comprises the following steps: performing dry mixing on red mud, slag, fly ash and cement which are dried and ground to specified fineness according to a preset proportion to obtain a uniform dry material; preparing a composite alkali activator from water glass and sodium hydroxide according to a molar ratio of 3: 1, premixing the composite alkali activator with water, and adding the dry material in batches to form wet slurry; and carrying out high-speed shearing and stirring on the wet slurry, and standing and curing to obtain the solid waste-based slurry which can be directly used for grouting. The method obviously improves the solid waste utilization rate, relieves the environmental pressure, and is suitable for related projects such as stratum settlement control, gushing water blocking, mine roadway broken rock mass supporting and underground cavity concrete lining crack repairing in tunnel and subway projects.

The invention belongs to the technical field of filling of an aluminum goaf under coal, and particularly relates to a bag type filling synergistic mineralization carbon dioxide sequestration method for mining a red mud-based filling material based on an aluminum strip under coal. Comprising the following steps that S1, filling bags are arranged; s2, grouting the aluminum layer bottom plate; s3, CO2 is conveyed; s4, red mud slurry is injected; s5, grouting between coal and aluminum layers; according to the method, through aluminum layer bottom plate grouting and coal aluminum interlayer grouting, Ordovician limestone water is effectively prevented from protruding out, harmful substances are effectively prevented from permeating underground water, meanwhile, a sealing cover layer for CO2 injection is also used, and the mineralization amount of CO2 is effectively increased. The main components of the red mud slurry are red mud, fly ash and crushed coal gangue, solid waste accumulation and environmental pollution are effectively reduced while the filling cost is remarkably reduced, recycling is achieved, the red mud is sealed in a flexible filling bag in a goaf, and if necessary, valuable elements in the red mud can be used for filling the goaf. And the tea leaves can also be extracted.

Described herein are methods, devices, materials, and systems for extracting target materials from iron-rich feedstocks. The iron-rich feedstock may be red mud, a natural occurring mineral, and / or a waste stream. The target materials may include a main constituent of the feedstock, a rare earth element, a precious metal, and / or a platinum group element. The invention may use a combination of electrochemical reactions and physical separation methods.

The invention relates to a co-treatment process for high-iron red mud and various carbon-containing solid wastes. The co-treatment process comprises the working procedures of raw material preparation, ball pressing, drying and pre-reduction, iron reduction, titanium-silicon reduction, tailing treatment and the like. According to the method, the problems of low iron grade and high impurity aluminum content of a red mud iron recovery process are solved, the comprehensive utilization problem of other solid wastes and the utilization problem of tailings after extraction are synchronously realized, and the purpose of treating wastes with wastes is realized.

The invention relates to the technical field of bauxite mining, in particular to a green mining method for bauxite under coal, and mainly solves the technical problems that pollutants in a goaf of an upper coal seam easily enter an aluminum layer, the recovery rate is low, an overlying rock layer easily collapses and a large amount of solid waste polluting the environment is generated in existing mining of bauxite under coal. The method comprises the following steps: S1, selecting a target rock stratum; s2, permeability transformation is conducted on the target rock stratum; s3, in-situ presplitting of bauxite; and S4, pillar-free comprehensive mechanical bag type filling mining is carried out. According to the method, old kiln water and poisonous and harmful gas in a coal seam goaf can be prevented from entering an aluminum mining working face during aluminum layer recovery, and the safety of aluminum layer recovery operation is greatly improved; ore body strength weakening can be achieved, fully-mechanized coal mining equipment loss is reduced, and fully-mechanized coal mining efficiency is improved; the recovery rate of bauxite can also be improved, and an overlying rock layer is prevented from collapsing; the coal gangue and the red mud can be treated and utilized in a large-scale and green manner, and the influence of industrial solid waste of the coal gangue and the red mud on the ecological environment is avoided.

The invention belongs to the technical field of solid waste concrete, and discloses fireproof sound-insulation heat-preservation light-weight high-strength all-solid waste concrete and a preparation method thereof.The fireproof sound-insulation heat-preservation light-weight high-strength all-solid waste concrete is prepared from an all-solid waste fireproof cementing material, all-solid waste light aggregate, water and a functional additive; the all-solid-waste fireproof cementing material comprises an alkaline activator component and an active powder component, the alkaline activator component comprises red mud and carbide slag in a mass ratio of (1.5-2.5): 1, and the active powder component comprises granulated blast furnace slag and low-temperature activated calcined coal gangue powder in a mass ratio of (1.0-1.8): 1; the all-solid-waste lightweight aggregate comprises coarse aggregate and fine aggregate in a mass ratio of (1-1.5): 1, wherein both the coarse aggregate and the fine aggregate comprise high-temperature expanded and roasted coal gangue lightweight aggregate; wherein the low-temperature activated and calcined coal gangue powder is obtained by performing gradient temperature control calcination on coal gangue at 650-800 DEG C and then grinding the coal gangue until the specific surface area is greater than or equal to 500m < 2 > / kg; the high-temperature expanded and roasted coal gangue lightweight aggregate is obtained by roasting and expanding coal gangue at 1100-1300 DEG C and then screening and grading.

The invention relates to the field of new materials, and discloses a red mud-based ceramic flat sheet membrane and a preparation method thereof. The red mud-based ceramic flat sheet membrane comprises a substrate and a separation layer integrally attached to the surface of the substrate, the matrix is prepared from the following raw materials in parts by weight: 2000 to 4000 parts of Al2O3 powder with the average particle size of 5000nm, 200 to 350 parts of corn starch, 300 to 500 parts of red mud, 400 to 600 parts of kaolin and 2 to 8 parts of polyvinyl alcohol; the separation layer is prepared from the following raw materials in parts by weight: 4-10 parts of Al2O3 powder with the average particle size of 5000nm, 1-3 parts of a dispersing agent, 0.1-0.3 part of a defoaming agent and 1-3 parts of polyvinyl alcohol. The red-mud-based ceramic flat sheet membrane has good physical properties, the preparation method is scientific and reasonable, and the red-mud-based ceramic flat sheet membrane has the characteristics of short production period, low raw material and sintering cost and the like.

The invention belongs to the technical field of mine filling materials, and discloses a solid-waste-based mine filling material and a preparation method thereof. The filling material comprises 70-100 parts of red mud, 1-10 parts of fly ash, 1-10 parts of slag, 5-20 parts of an acid activator, 10-30 parts of aggregate, 1-5 parts of a water reducing agent and 50-100 parts of water. The doping amount of the red mud of the filling material can reach 60% or above, the red mud is used as a main cementing material, formic acid, acetic acid, oxalic acid and other small-molecular organic acids are used as an acid activator, and an acid environment provided by the acid activator can reduce the alkalinity of the red mud and promote the dissolution of the red mud; the water and calcium silicate in the red mud can be more easily subjected to hydration reaction to generate a large amount of hydration products such as C-S-H gel, so that the strength of the filling material is enhanced. The acid activator used in the invention is low in cost, the cementing material and the aggregate are industrial solid wastes, and the cost of the mine filling material is reduced while the problem of resource utilization of the industrial solid wastes is solved.

The invention discloses an energy storage battery box based on light high-performance concrete and a preparation method of the energy storage battery box, and belongs to the technical field of energy storage equipment. The energy storage battery box provided by the invention comprises a light high-performance concrete base body and a metal net embedded in the light high-performance concrete base body, according to the lightweight high-performance concrete matrix, a multi-component gel system composed of ordinary Portland cement, a shrinkage reducing agent, a solid waste-based geopolymer and steel slag micro powder is adopted, and solid waste-based artificial sand, fibers and a solid waste-based filling material in a specific proportion are compounded, so that a lightweight high-strength intrinsically fireproof concrete material is successfully prepared; meanwhile, a large amount of industrial solid wastes such as the desulfurized gypsum, the red mud, the steel slag tailings and the fly ash are utilized, efficient resource utilization is achieved, the raw material cost and full-life-cycle carbon emission are remarkably reduced, and the production efficiency is high.

The invention belongs to the technical field of ceramics, and particularly relates to a three-dimensional effect glaze, a three-dimensional effect ceramic tile and a preparation method thereof. The three-dimensional effect glaze is composed of honeycomb ground glaze and honeycomb effect glaze; the honeycomb ground glaze comprises the following mineral components in percentage by mass: 20%-30% of quartz, 5%-10% of kaolin, 12%-18% of albite, 7%-15% of calcite, 2%-7% of wollastonite, 12%-17% of calcined talc, 15%-25% of calcined zinc oxide, 2%-6% of titanium dioxide, 2%-4% of glass powder, 1%-3% of strontium carbonate and 1%-5% of dolomite. The glaze with the honeycomb effect comprises the following mineral components in percentage by mass: 5%-15% of quartz, 5%-10% of kaolin, 40%-55% of albite, 2%-6% of barium ice feldspar, 2%-10% of calcite, 7%-15% of calcined talc, 1%-4% of calcined zinc oxide, 7%-15% of red mud and 3%-5% of coal gangue. The novel effect glaze is developed, the glaze surface is flat and smooth, meanwhile, the ground glaze is pushed to the surface through the gas phase disturbance effect, and the effect glaze sinks and wraps the ground glaze in a three-dimensional honeycomb shape.

The invention discloses environment-friendly ceramic and a preparation method thereof, and belongs to the technical field of ceramic. The environment-friendly ceramic comprises the following raw materials in parts by weight: 30-50 parts of red mud, 20-40 parts of fly ash, 10-25 parts of purple clay, 5-15 parts of quartz, 3-8 parts of a composite binder, 3-8 parts of a composite fluxing agent and 40-50 parts of deionized water. The environment-friendly ceramic prepared by the method disclosed by the invention has excellent breaking strength and apparent porosity.

The invention discloses a multi-element solid waste-based auxiliary cementing material and a preparation method thereof, the cementing material is prepared by taking steel slag, carbide slag and sintered red mud which are acidified and modified by microbial bacteria as raw materials, adding water, mixing and carbonizing; according to the invention, mineral components in the steel slag are effectively utilized, and the steel slag is modified through acid production of solid waste and microorganisms, so that a new mode of resource utilization of wastes is successfully established, and conversion from wastes to resources is realized; the carbon immobilization capacity of the modified steel slag is obviously enhanced through microbial modification, full-amount carbonization of the steel slag is achieved, compared with a traditional acid leaching carbonization method, the method is not limited to partial carbonization through filtrate any more, the preparation method is green and safe, environmental pollution and potential safety hazards caused by adopting strong acid in chemical acidification are avoided, and the method has great application prospects.

The invention discloses an iron tailing-based all-solid-waste clinker-free cementing material and a preparation method thereof, and belongs to the technical field of building materials. The cementing material comprises the following components in parts by weight: 30-50 parts of activated iron tailings, 10-20 parts of steel slag, 20-40 parts of mineral slag, 5-20 parts of phosphogypsum and 5-20 parts of an activating agent; a preparation method of the activated iron tailings comprises the following steps that the iron tailings and the red mud are mixed, then an alkaline solution is added, alkali-heat combined treatment is conducted for 2-6 h at the temperature of 150-230 DEG C after even mixing, and the activated iron tailings are obtained after drying. According to the method, the activity of the iron tailings and the red mud is improved through component complementation in the iron tailing activity excitation process, the dosage of NaOH in the alkali-heat excitation process is reduced, and the cementing material with high hydration activity is prepared through multi-source solid waste synergistic interaction in the clinker-free cementing material preparation process.

The invention discloses a functional material based on red mud waste loaded Fe-MOF as well as a preparation method and application of the functional material. At present, when a bayer process is adopted to smelt bauxite to obtain a metal material aluminum in industry, a solid waste named red mud can be generated. The accumulation of a large amount of red mud can cause serious pollution to the environment. Therefore, the invention provides a method for preparing a catalytic material based on acidified aluminum industrial waste red mud composite Fe-MOF and a treatment process of pollutants in a water environment. The composite material RM-MIL is prepared through an in-situ compounding method, and the composite material can remove 97.6% of organic pollutants in environmental water in an adsorption-degradation process. The composite material and the treatment process thereof developed by the invention have wide application value in the field of sewage treatment, and a feasible method is provided for resource development of the waste red mud by the Bayer process.

The invention discloses a red-mud-based multi-element solid waste cementing material as well as a preparation method and application thereof, and belongs to the technical field of building materials. The red-mud-based multi-element solid waste cementing material comprises the following components in parts by mass: 30-40 parts of red mud, 5-15 parts of fly ash, 10-20 parts of superfine slag powder, 30 parts of Portland cement, 4 parts of dihydrate gypsum and 2-25 parts of an alkali activator, alkaline components of the red mud are utilized to excite potential activity of the superfine slag powder and the fly ash, the additional alkaline activator excites potential activity in the red mud, and meanwhile, several industrial solid wastes and the Portland cement generate gel substances such as hydrated aluminosilicate under the synergistic effect, so that the mechanical property of the cement is improved; the building material meeting the strength requirement is provided while a large amount of red mud is consumed.

The invention relates to a process for extracting iron from red mud by using hydrogen reduction and electrolysis technologies, the red mud is a by-product generated in the industrial production process of aluminum, the environmental burden caused by the by-product can be solved, the carbon emission can be reduced, and the development of a green metallurgical technology can be promoted. Comprising the following steps: conveying red mud serving as a raw material into a rotary furnace, conveying hydrogen serving as a reducing medium into the rotary furnace, enabling iron oxide in the red mud to form hydrogen reduced iron in a furnace heating state and a hydrogen reducing atmosphere, conveying the red mud containing the hydrogen reduced iron into a sulfuric acid solution, the hydrogen reduced iron is dissolved in the sulfuric acid solution to form a sulfuric acid solution containing iron ions, the sulfuric acid solution containing the iron ions serves as an electrolyte in an electrolysis device, and electrolytic pure iron formed by electrolytic deposition of the iron ions is obtained through the electrolysis device.

The invention aims to provide a device and method for extracting iron from red mud and preparing iron oxide red, and belongs to the technical field of resource utilization, hydrochloric acid is adopted to leach iron element in the red mud, and a ferric chloride solution is separated from leachate through an extraction process. And then, carrying out alkali precipitation, washing and firing to prepare the high-purity iron oxide red. By using the method disclosed by the invention, the iron resource in the red mud can be recycled, so that the dual purposes of resource utilization and environment-friendly treatment are achieved.

The invention discloses a permeable laminated grid ecological bank protection material suitable for improvement of a dredged soil green material and a preparation method of the permeable laminated grid ecological bank protection material. The preparation method comprises the following steps that S1, a dredged soil green improver and dredged soil are evenly mixed in a dry mode, and homogeneous slurry is formed after stirring; s2, injecting the homogenized slurry into a mold, and pressing the homogenized slurry into hollow laminated grid units through a hydraulic forming machine; and S3, the permeable laminated grid units are naturally cured, and the permeable laminated grid ecological bank protection material suitable for improvement of the dredged soil green materials is formed. According to the invention, the dredged soil is taken as a matrix, and the mechanical property and ecological compatibility of the dredged soil are remarkably improved by adding the composite modifier composed of 11 components such as the steel slag micro powder, the red mud activator, the calcium sulphoaluminate expanding agent and the active magnesium oxide and combining the design of the three-layer permeable laminated grid structure.

The invention provides a negative carbon lightweight aggregate concrete mix proportion design method and a preparation method. The negative carbon lightweight aggregate concrete is prepared from the following components in parts by mass: 196 to 300 parts of negative carbon lightweight aggregate, 100 to 200 parts of regenerated sand, 30 to 50 parts of regenerated micro powder, 30 to 50 parts of Bayer red mud powder, 30 to 50 parts of slag, 1 to 3 parts of sodium hydroxide, 5 to 10 parts of water glass, 25 to 45 parts of water and 0.1 to 0.5 part of a water reducing agent. The carbon-loaded lightweight aggregate takes bagasse biochar as a core, and a shell material composed of regenerated micro powder, Bayer red mud powder and slag is wrapped outside the carbon-loaded lightweight aggregate, so that the strength is improved; according to the invention, the carbon-loaded lightweight aggregate is developed through bagasse biochar, and compared with traditional stone, the carbon emission is a negative value, and the advantage of low carbon is obvious. Meanwhile, carbon emission in the whole process is considered, the concrete mix proportion is designed by taking negative implicit carbon emission as a target, and building and industrial solid wastes are adopted as raw materials, so that the manufacturing cost is reduced, and resource waste is reduced.

The invention belongs to the technical field of industrial solid waste resource recycling, and discloses a nano composite filling material based on in-situ acid-base mutual modification enhancement and application thereof. According to the nano composite filling material, the alkalinity of the red mud and the acidity of the desulfurized gypsum are used for neutralization, the alkalinity of a system is reduced, a synergistic reaction is excited, a large number of ettringite crystals playing a key enhancing role are generated under the regulation and control of a nano material, and the ettringite crystals and a geopolymer form an interpenetrating network structure. The obtained slurry is low-viscosity and high-fluidity Newtonian fluid (diffusivity gt and 250 mm), the 7-day strength is larger than 2.0 MPa, the pH value is 7-9, and the fluorine ion concentration is lt; and the leaching of heavy metal ions is qualified, and the method is environment-friendly and safe. Efficient resource utilization of the red mud and the desulfurized gypsum is achieved, and the method is simple in process, low in cost and especially suitable for mine filling and engineering backfilling.

The invention discloses an all-solid-waste negative-carbon porous brick and a preparation method thereof, belongs to the technical field of green building materials for solid waste recycling and CO2 capture-storage-utilization, and particularly relates to a porous brick which takes red mud, steel slag and recycled aggregate as main raw materials, constructs a hierarchical pore structure through low-water-binder-ratio semi-dry pressing molding, and is prepared from the following raw materials in a solid-solid-waste negative-carbon porous brick. And directional carbonization curing is carried out by using cement kiln tail gas CO2 under the conditions of normal temperature and micro pressure, so that the national waste porous brick with negative carbon characteristic is prepared. According to the method, solid waste high doping, CO2 efficient solid storage and product performance synergistic improvement can be achieved.

The invention provides a method and system for separating and washing red mud in aluminum oxide production, and the method comprises the following steps: pretreating red mud slurry to improve the filtering performance of the red mud slurry; filtering the pretreated red mud slurry under set filtering conditions to form a red mud filter cake; in the filtering process, when the thickness of the dehydrated red mud filter cake reaches a set thickness, dehydrating the red mud filter cake so as to reduce the moisture content of the dehydrated red mud filter cake; performing multi-stage countercurrent washing on the dehydrated red mud filter cake to obtain a countercurrent washing solution; and carrying out purification treatment and concentration treatment on the countercurrent washing liquid, and returning the countercurrent washing liquid subjected to purification treatment and concentration treatment to the multi-stage countercurrent washing step as a washing liquid for cyclic utilization. The problem that the resource recycling rate is low in the red mud separating and washing process in aluminum oxide production is effectively solved.