355results about How to "Resolve disposal issues" patented technology

The invention relates to a process for biologically treating wastewater with sulfate and hydrochloric acid and recycling elemental sulfur, belonging to the technical fields of environmental protection and wastewater treatment, which is characterized in that in the process, the sludge acidic fermentation products from a wastewater treatment plant is used as carbon source sulfate reducing bacteria for treating acidic sulfate wastewater and recycling the elemental sulfur; the sulfate reducing bacteria SRB in an anaerobic biological reactor reduces sulfate SO4<2-> creature as hydrogen sulfide H2S of colorless sulfur bacteria CSB in an aerobic biofilm reactor reduces H2S or S<2->creature as the elemental sulfur and then the obtained substance is filtered and sand-scrapped by a slow sand filter; the elemental sulfur S in sand filtering material is completely dissolved by an extraction equipment; the extractant CS2, the sand filtering material and the biofilm are separated by a solid-liquid separator; the extracted solution is distilled by a distillation equipment; the distilled solution is parched by a drying device and then the elemental sulfur is recycled.In the invention the mine wastewater with the sulfate and the hydrochloric acid is treated; the elemental sulfur is recycled and the sludge from the wastewater treatment plant achieves resource utilization and harmlessness.

The invention discloses a method for harmless and recycling treatment of stainless steel acid washing waste water neutralization sludge, belonging to the field of harmful and valuable heavy metal resource recovery. The stainless steel acid washing waste water neutralization sludge is leached out by sulphuric acid, harmful and poisonous metals manganese, nickel and chromium enter into the leachate, and harmless treatment is carried out on the sludge. Separation, enrichment and recovery of metal resources of iron, manganese, chromium and nickel in the leachate are realized by adopting goethite method, potassium permanganate oxidation method, anion resin exchange method and chelate resin absorption method respectively, and effluent up to the standard is discharged after treatment or is returned to water consuming link in technologic process. The method of the invention has short technological flow, simple operation, management convenience, high recovery rate of valuable metal resources of manganese, nickel and chromium, recycling of multiple valuable metals is realized while the sludge is subject to harmless treatment, and unification of economic benefit, environmental benefit and social benefit is realized.

The invention relates to a recovery and comprehensive utilization method of heavy metals in stainless steel pickling wastewater sludge and discloses a method for recovering and recycling nickel and chrome in sludge generated during the treatment process of stainless wastewater. The method comprises the following steps: leading waste liquid during the pickling process to be directly used for leaching metal ions in the sludge to save the consumption of reagents; adding a certain quantity of acid or alkali in each reaction tank through arranging a plurality of reaction tanks; controlling a pH value; effectively separating various matters according to different solubility of inorganic compounds; researching and developing a recycling technology of the heavy metals in the stainless steel industrial sludge, wherein the recovery efficiency of the heavy metals like the chrome and the nickel is high; leading the recovered heavy metals to be used for smelting stainless steel; leading recovered iron to be used for preparing an efficient flocculating agent; and leading the flocculating agent to be used for sewage treatment to realize sewage reuse and save the treatment cost. The invention has the advantages of simple process and easy operation, as well as popularization and application.

The invention discloses a technique for producing methane with kitchen residue, straw fecal and active sludge as raw material, and relates to the key technique of methane production and a high solid methane fermentation reactor. It is characterized in: rigid anaerobic environment, adequate and good inoculum, necessary fermentation temperature, proper acid-base scale, proper fermentation concentration and carbon-hydrogen ration; the breeding speed safeguard of zymogeneous bacteria in fermentate; the killing of toxic and harmful bacterium; and the high solid reactor of stable operation. The invention is characterized in that it has significant academic meaning and practical meaning for producing methane with low investment, high stability and clean production.

The invention discloses a construction method for a water-permeable and water-retaining water-permeable pavement structure. The method comprises the steps of carrying out roadbed excavation, carrying out cushion laying, carrying out base course laying, carrying out leveling layer laying, carrying out surface layer laying and carrying out joint sand laying. According to the method, the process is simple, and the water-permeable pavement structure with high water permeability and high water retention is obtained through processing construction waste into recycled aggregate and constructing, so that the problem of construction waste disposal is solved, a great deal of building materials can be provided, meanwhile, energy problem, environmental problem and social problem resulting from the exploitation of natural stone resources are avoided, and thus the method is a multipurpose measure; particularly, the water-permeable pavement structure plays an important role in adjusting the humiture of urban ground surface due to high water permeability and high water retention.

According to the invention, by using dredged sediment from water body such as eutrophicated rivers and lakes as the aggregate, plant straws, plant ash, ordinary portland cement, an organic fertilizer, a release fertilizer, a water-retaining agent and the like are added into the dredged sediment with uniformly stirring to form the bare slope plant adaptability matrix with certain adhesive performance. By employing the wet-type guniting technology for two-layer matrix guniting, the plant adaptability matrix is used for the plant restoration of bare mountain slope and can form a new plant cover layer in a short period. The dredged sediment is used as the matrix to control the loss of water and soil, thus minimizing the dependence on the clay resource and the restoration cost in slope restoration and solving the issue of dredged sediment treatment by the resource mode; and furthermore, the restoration method provided by the invention has high environmental, ecological and economic benefits.

A technology for making energy-saving brick from paper-making mud includes such steps as proportionally mixing said mud with clay, shaping by brick maker, drying and calcining at 900-1050 deg. C. Its advantages are low energy consumption and high insulating performance of brick.

The invention relates to a soil improvement agent and a processing method thereof. The soil improvement agent comprises the following raw materials in parts by weight: 60-95 parts of desulfurized waste, 0.5-2.0 parts of inorganic accelerator, and 0.5-30 parts of organic accelerator. The soil improvement agent provided by the invention has the beneficial effects that calcium ions in the desulfurized waste are used to replace exchangeable sodium on the soil colloid, thus reducing the alkalization degree of the soil; at the same time, the excellent pore structure and physical property of the organic accelerator are used to improve the physical property of the soil and the granular structure of the soil, reduce the pH value of the soil, and improve the soil fertility; the inorganic accelerator can also improve the granular structure of the soil; in addition, with auxiliary inorganic fertilizer and organic fertilizer, the soil fertility of the soil can be further improved so as to provide nutrient contents for plant growth. To sum up, by adopting the scheme in the invention, unbalance of nutritive elements in the soil can be effectively overcome, the land capability is improved, the soil is loosened, and the fertilizer efficiency is increased, so that the soil salinization phenomenon is fundamentally harnessed step by step.

The invention discloses a modified magnetic sludge biological carbon and a preparation method and applications thereof. The modified magnetic sludge biological carbon is prepared by carbonizing residual sludge, modifying sludge by alkali, and modifying sludge by acid. The provided modified magnetic sludge biological carbon has the advantages of good magnetic property, large specific surface and pore volume, abundant pore structure, many surface adsorption functional groups and adsorption sites, and strong performance on removing target pollutants; and the preparation method has the advantages of simple preparation, easy operation, low cost, high production efficiency, and convenience for large scale production. The provided modified magnetic sludge biological carbon is used to remove tetracycline hydrochloride in water for the first time, has the advantages of large adsorption amount, strong adsorption performance, high adsorption efficiency, simple and convenient operation, short processing period, low processing cost, and easy separation and recovery, and has a strong performance on removing tetracycline hydrochloride. The maximal balance adsorption amount can reach 253.8 mg / g. The performance of the biological carbon is obviously stronger than that of unmodified magnetic sludge biological carbon.

The invention belongs to the field of solid waste reclamation comprehensive utilization and particularly relates to a soil conditioner prepared from sludge and a preparation method thereof. The soil conditioner is prepared from river and lake bottom mud, conditioner, medium sand, agricultural and forestry residues, biological manure and plant ash, wherein the conditioner is 5% to 8% of the mass of the river and lake bottom mud, the medium sand is 5% to 10% of the mass of the river and lake bottom mud, the agricultural and forestry residues are 5% to 10% of the mass of the river and lake bottom mud, the biological manure is 1% to 5% of the mass of the river and lake bottom mud, and the plant ash is 1% to 3% of the mass of the river and lake bottom mud. The soil conditioner prepared from sludge disclosed by the invention achieves resource utilization of sludge, also fully utilizes sludge, tailings or river and lake sand, tailing sand, pipe network sand and agricultural and forestry residues at the same, achieves the purpose of treating waste through waste, avoids solid waste landfill, land occupancy and secondary pollution, reduces engineering cost of land reclamation, landscaping, forest land plant and the like and is beneficial to ecological environment; in addition, the river and lake sand, the tailing sand, the pipe network sand and the agricultural and forestry residues are separated and sorted from pipe network sludge.

The invention discloses a goaf waste rock filling coal mining method of a flexible shield support in a half-edge coal seam, comprising the following steps: firstly arranging an alley way before coal mining, wherein the inclined alley way is arranged along a pitching surface according to an angle of 23-25 degrees, mining along the inclined direction from top to bottom and along the trending from east to west; secondly using a flexible shield support for coal mining with coal mining method, using the flexible shield support on a mining surface, tightening among the flexible shield supports by using back boards, using a steel rope to connect into an integral flexible shield support, and separating the goaf waste rock and coal mining space; and finally carrying out goaf waste rock filling. Through the method, safe production of half-edge coal seam can be realized, and simultaneously the handling problem of waste rock produced in underground coal mine can be solved.

The invention provides a heavy metal sludge soil restorer, a preparation method and an application thereof in sludge elimination. The adopted technical scheme comprises: municipal sludge is subjected to pretreatment, thermophiles are used for decomposing organic substances, and a heavy metal is added to treat microorganisms. After the sludge restorer is used in a test, the effective removal rate of various pollutants in soil reaches 95% or above, in line with national standards. At the same time, sulfate can be used to repair heavy metal land in situ, and is also a very good organic fertilizer, and is beneficial to reduction in the use of chemical reagents and chemical fertilizers in agricultural production, thereby eliminating pollution sources and secondary pollution from the source.

The invention relates to a conditioner for severely alkaline soil and a processing method of the conditioner. The conditioner for the severely alkaline soil comprises the following raw materials in parts by weight: 88-92 parts of desulfuration waste, 1-3 parts of inorganic accelerator and 5-11 parts of organic accelerator. According to the conditioner for the severely alkaline soil, calcium ions in the desulfuration waste are used for replacing exchangeable sodium on a soil colloid, so that the alkalisation degree of the soil is reduced; an excellent pore structure and physical properties of the organic accelerator are used for improving physical characteristics and a granular structure of the soil; the pH value of the soil is decreased; the soil fertility is increased; the inorganic accelerator also can improve the granular structure of the soil; an inorganic fertilizer and an organic fertilizer are additionally adopted to further increase the soil fertility; and nutritional ingredients are provided for crop growth. In a word, the conditioner can effectively overcome nutritional element unbalance in the soil, increase the soil fertility, loosen the soil, improve the fertilizer efficiency and fundamentality control soil salinization gradually.

The invention discloses a bacillus edaphicus liquid. The bacillus edaphicus liquid is obtained via separated fermentation of bacillus edaphicus using fermentation equipment. A fermentation medium of the separated fermentation comprises following ingredients, by mass, 40 to 60% of yeast waste liquid, 1.4 to 1.8% of silkworm chrysalis powder, 0.7 to 0.9% of peptone, 0.35 to 0.45% of gelatinized corn flour, 0.21 to 0.27% of NaCl, 0.14 to 0.18% of KH2PO4, 0.07 to 0.09% of MgSO4, and water. The invention discloses a liquid microbial leaf fertilizer, and a production method thereof. According to the liquid microbial leaf fertilizer, advantages of leaf fertilizers and microbial fertilizers are combined, effects and supplement of nutrient elements required by a plurality of crops at specific growing periods are realized quickly, fertilizer utilization rate is increased, fertilizer dosage is reduced, and production cost is also reduced.

The invention relates to an application of a moderate alkaline soil modifier to soil improvement. The moderate alkaline soil modifier comprises, by weight, 80 to 90 parts of desulfation wastes, 3 to 5 parts of inorganic accelerators and 8 to 15 parts of organic accelerators. According to the moderate alkaline soil modifier, calcium ions in the desulfation wastes are utilized to replace exchangeable sodium on soil colloid, so that the alkalinity of the soil is reduced; simultaneously excellent pore structures and physical properties of the organic accelerators are utilized, so that the physical properties and the granular structure of the soil can be improved, the potential of hydrogen (pH) value of the soil can be reduced, and the soil fertility is increased; the granular structure of the soil can be improved as well by the aid of the inorganic accelerators; and the soil fertility can be further improved by the aid of inorganic fertilizers and organic fertilizers, and nutritional ingredients can be provided for crop growth. In a word, the moderate alkaline soil modifier has the advantages that the unbalanced nutrition elements in the soil can be effectively avoided, the soil fertility can be improved, the soil can be loosened, the fertilizer efficiency is increased, and the soil salinization and alkalization can be gradually and radically treated.

The invention relates to the technical fields of oil deep processing and oil comprehensive utilization, and particularly discloses a preparation method for conjugated oil and application of the conjugated oil. The preparation method comprises the following steps: adding iodine into oil, reacting at the temperature of between 80 and 200DEG C for 0.5 to 5 hours under stirring in the nitrogen environment, and removing the iodine to obtain the conjugated oil. The preparation method is simple, the using amount of a catalyst is small, the conversion rate is high and solvents are not required to be added. Illegal cooking oil also can be taken as a raw material which is low in cost. The conjugated oil prepared can serve as a raw material for preparing fine chemicals, slow release fertilizers or controlled-release fertilizers.

The invention relates to a conditioner for moderately alkaline soil and a processing method of the conditioner. The conditioner for the moderately alkaline soil comprises the following raw materials in parts by weight: 80-90 parts of desulfuration waste, 3-5 parts of inorganic accelerator and 8-15 parts of organic accelerator. According to the conditioner for the moderately alkaline soil, calcium ions in the desulfuration waste are used for replacing exchangeable sodium on a soil colloid, so that the alkalisation degree of the soil is reduced; an excellent pore structure and physical properties of the organic accelerator are used for improving physical characteristics and a granular structure of the soil; the pH value of the soil is decreased; the soil fertility is increased; the inorganic accelerator also can improve the granular structure of the soil; an inorganic fertilizer and an organic fertilizer are additionally adopted to further increase the soil fertility; and nutritional ingredients are provided for crop growth. In a word, the conditioner can effectively overcome nutritional element unbalance in the soil, increase the soil fertility, loosen the soil, improve the fertilizer efficiency and fundamentality control soil salinization gradually.

The invention provides a method for producing monochloro methane by using dilute hydrochloric acid. The method comprises the following steps: 15 to 22 weight percent of the dilute hydrochloric acid and 40 to 52 percent of calcium chloride solution are mixed in a mixer and then enter into a hydrochloric acid analysis tower, the hydrochloric acid solution breaks a azeotropic point under boiling breaking action of calcium chloride, hydrogen chloride gas escapes from the top of the analysis tower, and the dilute calcium chloride solution is dewatered at a temperature of between 125 and 145 DEGC and a pressure of between 0.02 and 0.1MPa; compressed hydrogen chloride gas and vaporized methanol are superheated by a super-heater and enter a reactor to generate a mixture of monochloro methane, methane, ethyl chloride and methylene chloride; and the generated mixture enters a chilling machine, a gas phase enters a sulphuric acid drying system after the mixture is chilled and separated, and the gas phase is compressed to prepare the monochloro methane. The method effectively solves treatment problem of the dilute hydrochloric acid; the produced hydrogen chloride has high purity and little organic impurity; and the method reduces generating amount of heavy components in subsequent reaction, and improves the quality of the monochloro methane.

The invention discloses a microbial liquid. A fermentation medium used for preparing the microbial liquid comprises 40 to 60% of yeast waste liquid, 0.1 to 0.135% of starch, 0.35 to 0.45% of sucrose, 0.35 to 0.45% of peptone, 0.7 to 0.9% of soybean meal, 0.21 to 0.27% of KH2PO4, and water. The invention also provides a liquid microbial fertilizer prepared from the microbial liquid. The liquid microbial fertilizer comprises 1 to 3% of the microbial liquid, 10 to 40% of yeast waste liquid, an appropriate amount of inorganic nutrient, and water; wherein total nutrient N+P2O5+K2O provided by the inorganic nutrient is 4% or more. According to the liquid microbial fertilizer, yeast waste liquid is taken as the main organic compound, so that waste liquid disposal problem of yeast production enterprises is solved, and resource is saved. According to the liquid microbial fertilizer, advantages of liquid fertilizers and microbial fertilizers are combined, effect and supplement of nutrient elements are realized quickly, and application of microbial fertilizers is expended to the field of topdressing.

The invention relates to a chemical enhancing pretreatment method of sludge anaerobic digestion. The method is characterized in that perferrate production waste liquid is added into sludge, and the pH value of sludge is controlled below 11; the materials are well mixed by stirring; the obtained sludge is added into an anaerobic digestion system, and mesophilic anaerobic digestion is carried out. According to the invention, anaerobic digestion gas yield of the pretreated sludge is improved by more than 60% than that of untreated raw sludge. The invention has the advantage that when the anaerobic digestion efficiency of sludge is improved, a treatment and disposal problem of perferrate production waste liquid is solved. Harms to the environment and to public health caused by discharging are avoided, and perferrate production waste liquid can be utilized as a resource.

The invention provides a method for treating an eutrophication water body by utilizing an artificial marsh and a facility thereof. The method comprises the following steps that: an eutrophication water body to be treated is sent to an upflow type coarse filtering bed by a pumping and collecting pipeline; the upflow type coarse filtering bed carries out removing treatment to suspended substances and algae substances in the eutrophication water body; the water body treated by the upflow type coarse filtering bed is evenly distributed to a vertical flow ecological filtering bed by a water feeding and distributing system and subject to secondary biochemical treatment by the vertical flow ecological filtering bed; effluent water is recycled and reused; deposited sludge in the upflow type coarse filtering bed is discharged to a sludge drying filtering bed for stabilization treatment; and a wet sludge filtrate reflows to the upflow type coarse filtering bed for aftertreatment. The proposal of the invention adopts a method of combining the upflow type coarse filtering bed, the vertical flow ecological filtering bed and the sludge drying filtering bed to treat the eutrophication water body, can not only effectively remove the suspended substances and the algae substances but also solve the problem of treating blue algae sludge with low cost, has the characteristics of good algae removing effect and large water treatment amount and is widely suitable for the long-term water purification of the eutrophication water body.

The invention discloses a method for producing 2, 4-dichloroacetophenone. The method mainly includes acylation, hydrolysis, washing, distillation and crystallization, and m-dichlorobenzene and acetic anhydride are in acylation reaction under the effects of anhydrous aluminum trichloride. The method has the advantages that the m-dichlorobenzene is used as a raw material, the acetic anhydride is used as an acylating agent, A1C13 is used as a catalyst to prepare the 2, 4-dichloroacetophenone by means of reaction, and yield of obtained products is higher than that of products prepared by using acetyl chloride as an acylating agent; as the acetic anhydride is used as the acylating agent, the A1C13 is used as the catalyst and the m-dichlorobenzene which is extracted from chlorinated aromatics waste is comprehensively used as the raw material to prepare the 2, 4-dichloroacetophenone, by-products in a benzene chlorination process are disposed, reusing rate of chlorinated aromatics is increased, and the method has high economical and economical benefits.

The invention relates to a method for producing methane chloride through a byproduct hydrogen chloride in production process of tetrachloroethylene. The method comprises the steps of (1) condensing the mixed gas of excess chlorine and the byproduct hydrogen chloride in production process of tetrachloroethylene, then absorbing the chlorine by carbon tetrachloride between -5DEG C and -21DEG C, condensing again, eliminating the foam, buffering, and compressing; (2) heating up the hydrogen chloride and methyl alcohol, then reacting for 2-5 seconds under the action of a catalyst aluminum oxide so as to obtain the mixed product of methane chloride, methane, chloroethane and dichloromethane, and (3) chilling and separating the mixed product, sequentially water washing, alkali washing, drying by sulfuric acid and compressing the gas phase at 0.6-0.95MPa, condensing at 25-40DEG C, so as to prepare the methane chloride. According to the method, the chlorine is adsorbed by carbon tetrachloride, so that the chlorine is prevented from entering into a reaction system of the hydrogen chloride and methyl alcohol to affect the purity and selectivity of the reaction product methane chloride.

A method for producing biogas from kitchen wastes by anaerobic fermentation adopts two-stage anaerobic reaction to ferment kitchen wastes of various sources into biogas, effectively disposes kitchen wastes, and realizes harmless resource utilization of wastes. Multi-component combination process is adopted to realize staged and stepped disposal of kitchen wastes, stable system operation, good COD removal effect, high energy recovery rate, and good disposal effect under situation of complex material sources.

The present invention provides a liquid microbial fertilizer. The liquid microbial fertilizer comprises: 1-3% of micro-organism bacteria solution, 10-40% of yeast waste liquid, and a proper quantity of inorganic nutrients and water. In the micro-organism, the ratio of Bacillus subtilis fermentation to Streptomyces fermentation broth to jelly-like bacillus fermentation broth is 3: 0.5-3.0: 0.5-3.5. The present invention further provides a production method for the fertilizer. According to the liquid microbial fertilizer provided by the invention, the yeast waste liquid is taken as a major organic component for microbial fertilizer, thereby solving the problem of wastewater disposal in a yeast plant, and saving resources. The fertilizer provided by the invention, having both advantages of a liquid fertilizer and a microbial fertilizer, can not only exert an effect immediately, but also supply nutrient elements rapidly; moreover, the fertilizer can also improve soil organic matter, restore soil microbial flora, and extend application of the microbial fertilizer to the field of topdressing.

The invention belongs to the technical field of industrial waste treatment, and particularly relates to a resource recycling process and system for high-temperature plasma of chlorine-containing waste. The method comprises the steps that (1) the chlorine-containing waste is conveyed into a plasma gasifier through a feeding system; (2) synthesis gas produced through splitting decomposition is cooled by a first-stage waste heat exchanger; (3) after entering an acid absorption system to absorb acid, the synthesis gas enters an alkaline tower to be further deacidified; (4) the deacidified synthesis gas enters a secondary combustion chamber to be combusted, and generated high-temperature flue gas is cooled by a second-stage waste heat exchanger; (5) after the cooled flue gas enters a quench cooler to be subjected to quenching, the flue gas enters a bag-type dust remover for dust removal; (6) the flue gas with dust removed enters a flue heater to be warmed; (7) the flue gas enters an SCR catalytic tower to remove nitric oxide in the flue gas; and (8) after the flue gas subjected to SCR treatment enters the heat exchanger for heat exchange, the flue gas is drawn out by an induced draft fan, and the flue gas is discharged into the atmosphere through a chimney. By means of the resource recycling process and system, resource, harmless, reducing and stabilizing treatment of the chlorine-containing waste is achieved, and the system operation cost is low.

The invention discloses a method for improving the quality of a waste concrete recycled aggregate by using a sodium carbonate solution. The waste concrete recycled aggregate of which the particle size grade is 5-20mm is soaked in a Na2CO3 solution of which the mass concentration is 4-8%, and the soaking repair time is 15-25 days. The method provided by the invention has the following beneficial effect: the water absorption rate of the recycled aggregate is reduced, the apparent density is increased, the quality of the recycled aggregate is greatly improved, the recycled concrete coarse aggregate repaired by the sodium carbonate solution can be used for preparing new concrete when the water absorption rate and the apparent density of reach a III-grade standard of the recycled concrete coarse aggregate of a national standard GB / T25177-2010, and the problem of waste concrete construction waste disposal is solved.

The invention discloses a household garbage disposal system. Processing equipment of the household garbage disposal system successively comprises a primary crusher primarily crushing household garbage, a sorting conveyor manually sorting glass, rocks and non-combustible substances, a magnetic separator sorting magnetic substances, a secondary crusher crushing crushed substances of the household garbage into small pieces, a drying oven drying the small pieces of crushed substances by utilizing hot wind, an agitator putting additives into the dried small pieces and performing mixing processing, a primary pulverizer primarily pulverizing the small pieces with the additives into fragments, a screening machine sorting the nonmagnetic incombustible substances through proportion screening and rotating screening from the fragments, a secondary pulverizer secondarily pulverizing sorted pulverized substances without the nonmagnetic incombustible substances into small pulverized particles, a molding machine performing molding processing on the small pulverized particles after secondary pulverizing, and a cold dryer drying a molded garbage derived fuel by utilizing cold wind.

The invention discloses a method for preparing a high-purity calcium fluoride product from acid fluoride-containing wastewater, industrial calcium carbonate and acid fluoride-containing wastewater areused as the raw materials, by controlling the technological parameters of dosage, precipitation time and the like, the calcium fluoride is primarily and secondarily precipitated under the action of air flotation of CO2 produced in the precipitation process, the fluorine resource is efficiently recycled, the high-purity calcium fluoride product is prepared, moreover, the treated water is defluorinated in depth by using a calcium salt, so that the water reaches the emission standard. The flow is simple and convenient and is easy to operate, the operation cost is low, no secondary pollution is caused, the produced calcium fluoride product can replace an acid fluorite powder, and the method has an excellent application prospect.

The invention is applicable to the field of construction materials, and provides a reclaimed active ultrafine powder and a preparation method. The method is implemented by sequentially carrying out primary crushing, impurity removal, secondary crushing, tertiary crushing, metal removal, calcination, primary grinding, screening, secondary grinding and recalcination on construction waste. The invention uses waste concrete as the raw material to prepare the reclaimed active ultrafine powder which can be substituted for cement, thereby solving the problem in treatment of construction waste, and recycling the construction waste. The reclaimed active ultrafine powder provided by the invention has the advantages of large Blaine specific surface area, smaller curing dry shrinkage and very low hydration heat. Compared with Portland cement, the invention can obtain 28-day equal strength.