103 results about "Dealkalization" patented technology

The invention relates to an aluminum oxide industrial waste residue treatment technology, in particular to a red mud synchronous dealkalization soil treatment method. According to the method, citric acid and calcium nitrate are adopted as treating agents to cooperatively treat the red mud, the sodium content requirement of planting soil is taken as the standard, the red mud is dealkalized to reduce the sodium content, meanwhile, the granularity of the dealkalized red mud is improved, the organic matter content of the dealkalized red mud is increased, and then the dealkalized red mud and normal soil are mixed in proportion to form the dealkalized red mud soil. The physicochemical indexes of the dealkalized red mud soil are as follows: the volume weight is 1.18-1.26 g / cm < 3 >, the organic matter content is 10.6-12.3%, the pH value is 7.2-7.35, the EC is 0.492-0.562 ms / cm, and the specific surface area is 51.49-59.80 m < 2 > / g. The dealkalized red mud soil obtained through the synergistic treatment of the citric acid and the calcium nitrate completely meets the physicochemical properties of the soil and the planting requirements of plants.

The invention relates to a method for treating high-iron red mud by synchronously dealkalizing sucrose calcium and synchronously reducing and extracting iron, which comprises the following process steps of: (1) putting sucrose and calcium oxide into a beaker, adding deionized water, uniformly mixing, keeping the temperature and heating for 1.5 hours in a water bath kettle at the temperature of 70 DEG C and the speed of 420 r / min, and complexing the sucrose and Ca (OH) 2 to form sucrose calcium salt; (2) preparing a reaction solution from the sucrose calcium solution and quantified red mud, putting the reaction solution into an alkaline high-pressure reaction kettle, and reacting for 60 minutes under the conditions of 240 DEG C and 420 r / min; (3) a dealkalized reduction solution and dealkalized tailings are obtained, a solution sample tube is reserved, and the dealkalized tailings are ground and smashed; (4) the dealkalized tailings are subjected to magnetic separation to obtain iron ore concentrate and tailings, and after suction filtration and drying, the iron ore concentrate is subjected to grinding and magnetic separation to obtain iron ore concentrate and tailings; and (5) adjusting parameters of the iron ore concentrate under magnetic separation to improve the iron extraction rate. The utilization rate of the red mud is 100%, and the dealkalization rate and the extraction rate of sodium alkali and iron are 90% or above and 40% or above respectively.

The invention discloses a comprehensive dealkalization method for vanadium extraction waste slag, which comprises the following steps: mixing the vanadium extraction waste slag with a calcium additive, a carbonaceous reducing agent and sodium nitrite for pelletizing, decomposing a sodium-containing solid solution in the vanadium extraction waste slag by adopting a roasting process, and leaching a sodium-containing phase in the waste slag by adopting a hydrothermal leaching process, thereby achieving the purpose of dealkalization. And drying the leaching residues to obtain a sodium-removed iron-containing material, recycling the sodium-removed iron-containing material for an iron-making process, and performing multi-effect evaporation on the leaching solution to form a sodium-containing product which can be directly sold. The process equipment is simple, operation is easy and convenient, recycling of the vanadium extraction waste slag in iron and steel enterprises can be achieved, meanwhile, the process is high in energy utilization rate, little in environmental pollution and low in operation and maintenance cost, large-scale recycling of the vanadium extraction waste slag can be achieved, and good economic benefits and social benefits are achieved.

The invention relates to a Bayer process red mud dealkalization method, which comprises: adding a dealkalization seed crystal and an auxiliary agent into Bayer process red mud raw stock to dealkalize the Bayer process red mud raw stock to obtain dealkalized red mud slurry; wherein the auxiliary agent comprises a catalytic auxiliary agent with a viscosity reduction effect and a dealkalization auxiliary agent, and the dealkalization auxiliary agent comprises at least one of the following raw material components: calcium hydroxide and calcium oxide. According to the Bayer process red mud dealkalization method provided by the invention, under the synergistic effect of the catalytic promoter with a viscosity reduction effect, the dealkalization promoter containing calcium hydroxide and / or calcium oxide and the dealkalization seed crystal, and by matching with mild dealkalization temperature and relatively short dealkalization time, the purpose of improving the dealkalization efficiency of the Bayer process red mud primary pulp is achieved; and the dealkalization rate reaches 75% or above.

The invention provides porous calcium silicate and a preparation method thereof. The preparation method comprises the following steps: providing a high-modulus water glass solution as a silicon source, providing lime milk as a calcium source, adding dodecyl trimethyl ammonium chloride and citric acid betaine to obtain a mixed solution, heating the mixed solution, and carrying out a synthetic reaction with lime to obtain calcium silicate slurry; carrying out pressure filtration on the calcium silicate slurry to obtain a crude calcium silicate filter cake; adding water and pulping to obtain slurry, heating the slurry, adding a dealkalizing agent, keeping the temperature at 90-95 DEG C, and carrying out dealkalization reaction to generate dealkalized calcium silicate slurry; and carrying out solid-liquid separation on the alkali-treated calcium silicate slurry to obtain a calcium silicate filter cake, drying and scattering to obtain the finished product porous calcium silicate. The specific surface area of the porous calcium silicate is obviously increased.

The invention discloses an efficient consolidation agent for tailings in an underground mine filling mining method and a preparation method thereof, and relates to the technical field of consolidation agents, the consolidation agent is prepared from a gelling base material, a nano reinforcing agent, a chemical exciting agent and an organic fiber reinforcing agent according to a specific mass ratio; aiming at the problems of unstable volume, insufficient strength and the like of a traditional consolidation agent, through high-temperature calcination of the steel slag to eliminate harmful components, dealkalization treatment of the red mud, acid activation of the phosphogypsum and volcanic ash reaction of the fly ash, the volume stability and the gelling activity of a filling body are remarkably improved, and the consolidation agent is suitable for complex underground environment requirements; aiming at the pain points of low early strength, weak interface bonding and the like of the consolidation agent, the cohesion is improved by strong bonding of the surface-modified nano SiO2 and a gelling base material, a chemical exciting agent is added to cooperate with CO2 carbonization to generate nano crystal nucleuses, hydration sites are provided, a pore structure is optimized, bleeding is inhibited, the fluidity and stability of slurry can be effectively improved, and the consolidation effect is good. And the requirements of underground filling homogeneity and pumpability are met.

The invention belongs to the technical field of environmental protection and solid waste recycling, and particularly relates to a method for passivating and completely dealkalizing red mud and reserving valuable metal components. According to the method, the amount of added accurate dealkalization acid is limited through an acid amount formula, a weak acid reaction environment is created, only alkaline substances contained in the red mud are limited to participate in a neutralization reaction by controlling parameters such as passivation dosage, liquid-solid ratio, stirring time and temperature, water-soluble alkali salt is generated, then the alkali salt is separated and discharged in a filtering mode, and the water-soluble alkali salt is obtained. And preparing a dealkalized red mud filter cake. In the whole reaction process, Fe2O3, TiO2 and other metal oxide components are passivated by the passivator due to a weak acid environment, and the oxidation effect is basically completely retained in the dealkalized red mud filter cake. The alkali content of the dealkalized red mud is zero, the iron content is increased, and the dealkalized red mud can be directly used as refined iron powder or a catalyst, an adsorbent, a building material, a roadbed material and the like.

The invention relates to the technical field of float glass production, and discloses a high-aluminum float glass dealkalization uniformity monitoring method which comprises the following steps: S1, cutting glass subjected to dealkalization treatment, placing the cut glass in a container, soaking the cut glass in a weak acid solution, cleaning the soaked glass, detecting the state of roller marks on the surface of the glass, and increasing the usage amount of SO2 in a tin bath when the occurrence proportion of the roller marks on the glass exceeds 10%; s2, soaking the glass in a reinforcing acid solution, cleaning and detecting the dimness state of the glass, and reducing the usage amount of SO2 in a tin bath when the dimness proportion exceeds 10% or above; through the operation, the dealkalization amount of the glass is controlled. According to the method, the roller marks, the obscuration condition and the proportion are generated after glass soaking treatment, dealkalization on the surface of the glass is monitored, the dealkalization uniformity can be effectively controlled, and the method is simple in technological process, does not need to add expensive equipment and is easy to apply and popularize.

The invention belongs to the technical field of solid waste resource utilization, and particularly relates to a red mud-based multifunctional water treatment agent and a preparation method thereof. The method comprises the steps of red mud dealkalization, drying and crushing, acid dissolution reaction, pH regulation and control, function enhancement, slow-release carrier forming and the like, and by introducing a modified polyacrylamide functional additive and a compound flocculant, the removal capacity of the treatment agent on heavy metal ions, organic pollutants and high-hardness ions is effectively improved; sodium alginate-polyvinyl alcohol is adopted to construct an ionic crosslinking type slow release system, so that the combination of long-acting release and broad-spectrum purification functions is realized. Compared with the prior art, the method has the advantages that resource utilization of the red mud waste is achieved, and the prepared water treatment agent has the remarkable advantages of being stable in structure, high in adaptability, high in treatment efficiency and the like.

This invention discloses a lithium slag dealkalization treatment agent and a method for the resource utilization of lithium slag in building materials, comprising the following raw materials in parts by weight: 50-80 parts sodium hydroxide, 30-50 parts water glass, 5-15 parts polycarboxylate superplasticizer, and 10-20 parts calcium carbonate. This invention has the advantage of being environmentally friendly and solves the problems of existing lithium slag resource utilization methods, such as the inconvenience of preparing high-strength, high-insulation building materials from waste lithium slag, insufficient strength of lithium slag building materials making them unsuitable for load-bearing structures or high-load scenarios, limiting their use to low-strength filler materials or non-structural components, significantly reducing their economic value, and poor insulation performance failing to meet energy-saving building standards, resulting in a lack of competitiveness in scenarios requiring thermal insulation such as walls or roofs.

The application discloses a kind of red mud gradient depth purification-rare earth-radioactivity synergistic target purification method, by " hierarchical pretreatment and microwave modification→three-stage gradient dealkalization→rare earth-radioactivity synergistic target purification→full quantization recycling" four-stage integrated process, realize red mud harmless and high-value utilization.The three-stage gradient dealkalization uses microwave-CO2-biological synergic system, after dealkalization pH≤8.0, Na2O content<1%;Rare earth-radioactivity purification is extracted by HDES and coupled with multi-ligand magnetic material system, light rare earth recovery rate≥95%, middle heavy / rare earth recovery rate≥90%, U / Th removal rate≥95%;Full quantization recycling realizes red mud total utilization rate≥98.5%, wastewater reuse rate≥95%, every ton of red mud fixed CO2≥0.2 tons.The application is suitable for various high-alkali, containing radioactive and rare earth red mud treatment, with environmental benefits and economic benefits.

According to the biomass dealkalization method and the prepared low-alkali biomass fuel, the cavitation effect formed by propagation of high-frequency ultrasonic waves in liquid is utilized, instant high pressure of hundreds of atmospheres can be generated in microseconds, and along with the local high temperature phenomenon, the biomass structure can be rapidly destroyed, and the low-alkali biomass fuel can be used for dealkalization of biomass. The internal alkali metal and alkaline earth metal elements are promoted to be quickly released; the catalyst interacts with carbon dioxide to form a dissolved or precipitated state, so that the removal efficiency of alkali metal and alkaline earth metal is greatly improved. Compared with the prior art, the method effectively solves the problem that a conventional method is low in efficiency under the conditions of short time and large solid-to-liquid ratio; and a large amount of acid solution is not needed, so that the dealkalization cost and the equipment corrosion risk are reduced. Therefore, the technological process is simplified, an efficient and environment-friendly technical choice is provided for large-scale industrial application, and the method has a wide application prospect.

The invention discloses a process for dealkalizing and deeply reducing red mud through gradient temperature control treatment, which comprises the following steps: 1) accurately metering raw materials and grinding; 2) feeding the ground raw materials into a red mud stirrer, and stirring at a gradient rotating speed; 3) feeding the stirred and mixed raw materials into a granulator for granulation, and pressing the materials into particle materials with the particle size of 5-15mm; 4) feeding the particle material into a dealkalization solid-phase reaction device, and forming a particle material after a solid-phase reaction in a reducing atmosphere; (5) feeding the particle material after the solid-phase reaction into a cooling machine, and slowly cooling in a furnace by adopting a nitrogen direct circulating cooling method; 6) crushing the cooled material by a crusher until the particle size is less than 5mm; 7) performing magnetic separation on the ground powder by a high-gradient magnetic separator.According to the method, efficient dealkalization and iron element reduction separation are realized through high-temperature dealkalization pre-reduction and high-temperature deep reduction melt separation.

The present invention relates to a dealkalization device and method for producing red mud in the alumina industry. The device comprises: at least one mixer; at least one settling tank; wherein the at least one settling tank and the at least one mixer are sequentially connected in series and spaced apart; a dealkalization reaction tank for dealkalizing an underflow, wherein, in the dealkalization reaction tank, lime milk is added to the underflow to obtain a red mud-lime milk mixture, which is then introduced into high-temperature steam for chemical reaction to obtain a red mud residue; the inlet of the dealkalization reaction tank is connected to the outlet of the last settling tank; a filter press for filtering the red mud residue to obtain a filter cake and a filtrate; wherein the inlet of the filter press is connected to the outlet of the dealkalization reaction tank; a red mud storage tank for storing the filter cake; wherein the red mud storage tank is connected to the outlet of the filter press. The device solves the technical problems in the prior art of the traditional lime Bayer process for producing alumina, such as large alumina loss, large alkali loss, and high energy consumption and production cost.

The invention discloses a red mud dealkalization method. Specifically, high-concentration bottom water collected from the bottom of a Maotai-flavor liquor brewing pit is used as a dealkalization agent. Specifically, the steps are as follows: first, the filter press red mud produced by an alumina plant is crushed and sieved, and then the dealkalization agent is evenly mixed with the red mud under the sieve, and after reacting at 20-50 DEG C for a certain time, an appropriate amount of a decolorizing agent is added, stirred evenly, and then the dealkalization red mud is obtained by filter pressing. The method can effectively remove alkali from the red mud and promote the agglomeration of red mud particles. The dealkalized red mud can be applied to the fields of soil, building materials, water treatment agents, etc. The entire dealkalization process of the method is green, low-carbon, environmentally friendly, and low-cost, and has a prospect for industrial application.

The invention provides a microwave hydrothermal curing red mud-based building block paving material and a preparation method thereof, and belongs to the technical field of industrial solid waste resource utilization. The preparation method comprises the following steps: adding water into raw materials comprising dealkalized red mud, carbide slag, ardealite, steel slag powder and aluminum tailings, uniformly mixing, carrying out compression molding, putting into a microwave reaction kettle, and carrying out hydrothermal curing treatment under the conditions that microwave irradiation is carried out and the temperature is 100-200 DEG C and the pressure is 0.2-0.4 MPa, so as to obtain the red mud-based building block paving material. According to the preparation method disclosed by the invention, the curing rate of heavy metal ions in an industrial solid waste material is improved and the radioactive hazard of the material is weakened through a quadruple synergistic mechanism of dealkalization pretreatment, low-temperature hydrothermal crystallization, heavy metal ion curing and radiation shielding, so that the red-mud-based building block paving material has relatively high strength; the problem of saltpetering of the red mud is effectively solved, and the application requirements of municipal engineering, river dike dam protection, hazardous waste protection and other scenes can be met.

The invention discloses a method for recovering iron, aluminum and sodium in red mud, which comprises the following steps: mixing the red mud and an alkaline solution, and introducing hydrogen into high-temperature and high-pressure equipment to react; carrying out solid-liquid separation on the slurry after reaction, and carrying out magnetic separation after solid-phase grinding to obtain concentrate and tailings; and adding a calcium-containing additive aqueous solution into the tailings for dealkalization reaction to obtain dealkalized residues and dilute alkali liquor. Red mud, an alkaline solution and hydrogen are stirred and reacted in high-temperature and high-pressure reaction equipment, (aluminum) hematite and (aluminum) goethite in the red mud are completely converted into ferroferric oxide, the purpose of extracting aluminum in the red mud is achieved, solid-liquid separation is conducted on slurry after the reaction, ferroferric oxide in a solid phase is separated through magnetic separation, and the iron content in concentrate is high; the method can cooperate with large-scale absorption in the iron and steel industry, and also considers recovery of iron minerals; comprehensive recovery of iron, aluminum and sodium in the red mud is realized, and the method has the advantage of environmental friendliness.

The invention relates to a mixing device, and provides an efficient red mud dealkalization device which comprises an outer tank body with an opening in the lower end and obliquely arranged, a bracket for supporting the outer tank body, a driving device for driving the outer tank body to rotate, an inner tank body detachably arranged in the outer tank body and with an opening in the upper end, and a first connecting ring arranged at the lower end part of the outer tank body, the first connecting ring is arranged at the upper end part of the outer tank body, the second connecting ring is arranged at the lower end part of the inner tank body, the barrel-shaped filter cloth is laid on the inner wall of the inner tank body, the pressurizing device is arranged at the upper end of the outer tank body, the feeding device is arranged at the upper end of the outer tank body, the spoilers are arranged in the outer tank body, and the extrusion rings are arranged at the lower ends of the spoilers; the first connecting ring and the second connecting ring are detachably connected in a sealed mode, the multiple spoilers are distributed in a circumferential mode and abut against the filter cloth on the inner side wall of the inner tank body, and the pressing ring is used for extruding the filter cloth on the inner bottom wall of the inner tank body. According to the efficient red mud dealkalization device, red mud can be dealkalized efficiently, and the slurry mixing efficiency is improved.

The utility model discloses an efficient demercuration and resource recovery device, which comprises a fixed column, a pipeline system and a demercuration system, the pipeline system is arranged on the front side of the fixed column, and the demercuration system is arranged on the rear side of the fixed column. According to the present invention, the flue gas passes through the adsorption film, the adsorption film adopts the CI-PANI-coated MWCNTs material, the polyaniline (PANI) is the conductive polymer, and does not consume the energy during the Hg < 0 > removal process, the adsorbed Hg is stable at the high temperature and does not release the Hg again, and the easy acid doping / dealkalization performance and the excellent environmental stability make the regeneration method simple and mild, and the method has the characteristics of environmental protection and environmental protection. Therefore, the adsorption film has excellent reusability, good water resistance and high thermal stability, and has cyclic utilization and relatively high practicability.

The invention discloses microwave activated red mud-biomass solid waste magnesium oxychloride aggregate and a circulation method, and belongs to the technical field of solid waste recycling and negative carbon building materials. The method comprises the following steps: mixing Bayer process red mud and biomass solid waste according to a mass ratio of 3: 1-1: 1, and carrying out microwave activation at 500-1200 DEG C for 10-60 minutes; carrying out magnetic separation on the activated material to obtain an iron ore concentrate-biomass charcoal composite material which can be used as a wave-absorbing material, so as to obtain low-alkali activated red mud residues; 10-50 parts of the residues, 15-40 parts of light calcined magnesia powder and 15-40 parts of a magnesium chloride solution are mixed, the molar ratio of magnesium oxide to magnesium chloride is 6-9, and solid waste aggregate is obtained after forming and curing; the waste aggregate is regenerated into active powder after being subjected to heat treatment at 400-800 DEG C for 0.5-2 hours, and new aggregate can be circularly prepared. According to the method, red mud dealkalization and iron recovery, high-value utilization of biomass and carbon sequestration and stability augmentation and closed-loop circulation of aggregate are synchronously realized.

The application relates to a paste filling material, raw material components of the paste filling material comprising: a red mud-based active material, a first red mud, a pumping agent and a stabilizer; wherein the red mud-based active material is obtained by sintering of dealkalization red mud and industrial by-product gypsum, raw material components of the dealkalization red mud comprising a second red mud and calcium oxide-rich slag. The application converts the red mud into the paste filling material through two-stage utilization, has the advantages of simple process and low cost, and has excellent performances such as good fluidity, high mechanical strength and slight expansion, reaches the performance requirements of the mine filling material, and realizes high-content utilization of the red mud in the filling material field.

The invention relates to a powdery lime slurrying system aiming at Bayer process red mud dealkalization, which belongs to the technical field of aluminum oxide production and comprises a lime bin, slurrying reaction equipment, a buffer tank, a settling tank and an overflow tank, a discharging pipe of the metering conveying device and a slurrying water inlet pipe are both connected with the feeding end of the slurrying reaction device, the slurrying reaction device is connected with the buffer tank, the buffer tank is connected with the settling tank through a vertical buffer pump arranged on the top, and the settling tank is connected with the overflow tank through an overflow pipe. The method solves the problems that in the Bayer process aluminum oxide production process, after the red mud dealkalization procedure is added, the dosage of lime milk is sharply increased, and the treatment capacity of a traditional ashing system is insufficient, meanwhile, graded utilization of high-concentration lime milk and low-concentration lime milk is achieved, and the production efficiency of lime milk preparation is improved.

The invention relates to a method for preparing calcium aluminate by using alkaline residues, which comprises the following steps: adding an induced settling agent into alkaline residue slurry to promote the growth of calcium carbonate crystal grains in the alkaline residue slurry and further promote the settling of calcium carbonate, aluminum calcium carbonate and other products so as to facilitate subsequent better solid-liquid separation; carrying out dealkalization type liquid-solid separation treatment on the sedimentation liquid to obtain low-sodium modified alkaline residues and catalytic filtrate; reacting the catalytic filtrate with aluminum ash to obtain sodium aluminate, ammonia gas, methane and hydrogen; then carrying out solid-liquid separation to obtain modified aluminum ash with less leached fluorine and less volatile ammonia; and preheating and calcining the modified alkaline residues and the modified aluminum ash to obtain a target calcium aluminate product. The preparation method provides a thought for preparing high-quality calcium aluminate from the alkali residues discharged in the Bayer process aluminum oxide production process.

The invention provides a method for assisting red mud dealkalization by using a freeze-thaw method and a red mud dealkalization system. The red mud dealkalization method comprises the steps of water replenishing saturation, freezing, melting suction, component detection and repeated treatment, and the water replenishing saturation step comprises the steps of burying a bagged sand well into a tamped red mud soil body, replenishing water to the red mud soil body by replenishing an eluting agent solution into the bagged sand well, and forming a water-supplementing saturated soil body until the soil-water potential in the red soil body is balanced. Freeze-thaw circulation of the red mud is achieved through an artificial refrigeration method, a bagged sand well is used as a fluid infusion well method, effective dealkalization of the red mud is achieved in combination with an acid leaching method, alkali in the dealkalized red mud is remarkably reduced, the Na2O content can reach 1% or below, and the dealkalization effect is good. The material can be used for roadbed materials of roads, ground hardening materials for saline-alkali soil transformation, cement raw materials, building raw materials and the like. The invention also provides a red mud dealkalization system.

The present invention provides a vanadium extraction tailings calcification reduction dealkalization method. The method comprises the following steps: pre-treating the vanadium extraction tailings with a composite low-temperature curing agent for pelletization to prepare a silicon-free pellet raw material that releases CO2 at high temperature; adopting a hot air drying-microwave consolidation process to strengthen the strength of the pellets; and then using a rotary kiln for reduction roasting, so that the alkali metals in the vanadium extraction tailings enter the gas phase and are removed through dust removal. The obtained slag phase has high iron and vanadium metallization rates and can be directly used in a blast furnace. The alkali metals in the vanadium extraction tailings are effectively removed, enabling the recycling of the vanadium extraction tailings in the ironmaking process, improving the recovery rate of valuable elements in the vanadium extraction tailings, and increasing the blast furnace's ability to process the vanadium extraction tailings.

The invention discloses fly ash-red mud based ultrafine powder and a preparation method and application thereof.The fly ash-red mud based ultrafine powder is prepared from, by weight, 50-70 parts of modified fly ash, 10-35 parts of dealkalized red mud, 4-10 parts of waste glass micro powder and 4-10 parts of nanometer silicon-aluminum sol, the dealkalized red mud is prepared from red mud through calcination-secondary leaching. The fly ash-red mud-based ultrafine powder prepared by the invention can replace S95-grade mineral powder, is remarkably better in working performance, mechanical property and durability after being used for preparing sea sand concrete, can effectively prolong the service life of marine environment concrete engineering while reducing the production cost of the sea sand concrete, and has higher engineering application value.

The invention provides a method for extracting scandium in red mud, and relates to the technical field of red mud resourceful treatment. The method comprises the following steps: firstly, performing activation pretreatment on red mud to obtain activated red mud slurry; carbon dioxide is introduced into the activated red mud slurry for dealkalization carbonization, carbonized red mud slurry is obtained, and a leaching aid is generated; and adding a leaching agent and an extraction agent into the carbonized red mud slurry, and carrying out one-step extraction leaching on the red mud to finally obtain a scandium product. The method is high in leaching and extraction efficiency, the leaching agent and the extraction agent can be recycled, the process is simple, the cost is low, and the method is suitable for batch treatment.

The present application belongs to the technical field of environmental protection and solid waste recycling, and particularly relates to a method for passivating, completely removing alkali and retaining valuable metal components of red mud. The present application limits the precise alkali removal acid amount by an acid amount formula, creates a weak acid reaction environment, and limits only the alkali substances contained in the red mud to participate in the neutralization reaction by controlling the passivation agent amount, liquid-solid ratio, stirring time and temperature and other parameters, to generate alkali salt dissolved in water, and then separates and discharges the alkali salt by filtration to prepare the alkali-removed red mud filter cake. During the whole reaction process, the metal oxide components such as Fe2O3 and TiO2 are basically completely retained in the alkali-removed red mud filter cake due to the weak acid environment and the passivation and oxidation of the passivation agent. The alkali-removed red mud obtained by the present application contains zero alkali and increased iron content, and can be directly used as fine iron powder or catalyst, adsorbent, building material, roadbed material and the like.

The invention discloses a red mud all-element high-value resource recycling process, and relates to the technical field of red mud. Sodium silicate and sodium alkali are efficiently separated through washing of the double-helix mud washing machine, concentration of the thickener, dealkalization leaching of ammonium chloride, classification of the hydrocyclone, targeted treatment of coarse and fine particles, high-value utilization of silicon alkali overflow liquid, two-stage membrane electrodialysis and the like; the problems of recovery of sodium silicate and electronic-grade silica sol in the red mud, removal and conversion of sodium hydroxide into high-purity sodium hydroxide and full-component decomposition, separation and enrichment of valuable elements (silicon, aluminum, iron, titanium, vanadium, heavy metals and three-rare elements) are completely solved, and finally full-element utilization of the red mud, especially enrichment of alkali-soluble three-rare elements, is realized. The commercial value of the red mud is far higher than that of bauxite, and a feasible industrial path is provided for harmless, recycling and high-value utilization of the red mud.

The invention relates to the technical field of mine filling materials, in particular to an alkali-activated red mud filling material and a preparation method and application thereof. The invention provides an alkali-activated red mud filling material, which is prepared from the following raw materials in parts by weight: 70 to 90 parts of red mud, 10 to 20 parts of a dealkalizing agent, 1 to 3 parts of a dealkalizing-coagulating aid, 10 to 30 parts of an auxiliary cementing material, 0.1 to 0.5 part of a retarder, 0.1 to 0.3 part of a water-retaining agent and 0.1 to 0.3 part of an interface reinforcing agent, wherein the weight part of the red mud is the weight part of the dry basis red mud. The alkali-activated red mud filling material prepared by adopting a method combining a dealkalization technology and an alkali-activated technology provided by the invention is faster in coagulation, higher in compressive strength and lower in bleeding rate, meanwhile, the preparation method solves the problems that a large amount of red mud is high in dealkalization cost and difficult to fully utilize after dealkalization, and has great practical application value.