112 results about "Ferric hydroxide" patented technology

The invention discloses a clean, efficient and low-cost lithium extraction slag utilization method which comprises the following steps: mixing lithium extraction slag with a fluxing agent, and sequentially carrying out roasting treatment, solid-liquid separation treatment, aging treatment and water leaching treatment to obtain a second solid-liquid mixture; carrying out solid-liquid separation treatment on the second solid-liquid mixture to obtain a second filter residue and a second filtrate; performing carbon separation method treatment on the first filtrate to obtain a third solid-liquid mixture; carrying out solid-liquid separation treatment on the third solid-liquid mixture to obtain a third filter residue and a third filtrate; the main component of the second filter residue and the third filter residue is white carbon black; performing heat treatment on the second filtrate and the third filtrate to obtain a fourth solid-liquid mixture; performing solid-liquid separation treatment on the fourth solid-liquid mixture to obtain fourth filter residues and fourth filtrate; the main components of the fourth filter residue are aluminum hydroxide and ferric hydroxide; and separating the fourth filtrate to obtain a sodium sulfate crystal substance and a potassium sulfate crystal substance.

The application provides a clean recycling method of waste lithium iron phosphate positive electrode material, which comprises the following steps: (1) the waste lithium iron phosphate positive electrode material is pretreated to separate aluminum foil, a binder and carbon, and a mixture containing phosphorus, iron and lithium is obtained; (2) the mixture is subjected to oxidative leaching in a sodium hydroxide solution, and the obtained mixed slurry is subjected to solid-liquid separation to obtain iron hydroxide precipitation and a leaching solution; (3) sodium carbonate and the leaching solution are mixed, lithium is precipitated, and solid-liquid separation is performed to obtain lithium carbonate and a separation solution; the separation solution is subjected to crystallization and solid-liquid separation to obtain sodium phosphate crystals; (4) the lithium carbonate in step (2), the iron hydroxide precipitation in step (3), phosphoric acid and carbon powder are mixed, and calcination is performed to obtain lithium iron phosphate. The clean recycling method can realize high-purity and high-efficiency recycling of the waste lithium iron phosphate positive electrode material, and the process flow is clean and environmentally friendly.

The invention provides continuous wastewater treatment equipment, which belongs to the technical field of wastewater treatment, and comprises a treatment tank and an observation window arranged in the middle of the treatment tank, and further comprises a multi-stage treatment assembly, a pollution discharge purification assembly and a stripping assembly, deep purification of the wastewater is realized through multi-stage treatment; the vertical spraying is combined with the stirring of the fan blades and the scrapers, strong water flow scouring force is formed above the elastic filter plate, meanwhile, the convex plates periodically extrude the elastic filter plate during rotation to enable the elastic filter plate to vibrate, suspended particles and impurities can be effectively prevented from being accumulated on the surface of the elastic filter plate, the risk of filter plate blockage is reduced, and meanwhile, the service life of the filter plate is prolonged. Ferric hydroxide colloid generated by ferrite reaction can more uniformly adsorb suspended particles under the driving of upper and lower water flows, and the precipitation separation of the suspended particles is accelerated; the connecting shaft rotates to drive the mounting cylinder, the arc-shaped groove of the trigger cavity is matched with the ball, the oxidation disc vibrates, the vibration strength is adjusted according to the descending amplitude of the oxidation disc, and the overall wastewater treatment efficiency is improved.

The invention provides a titanium recovery and all-component recycling cooperative treatment method in sulfate process titanium dioxide waste acid. The method comprises the following steps: diffusion dialysis separation, sulfuric acid concentration, metal separation, titanium component recycling, iron and manganese precipitation and precipitation waste liquid treatment. According to the titanium recovery and all-component recycling co-processing method in the sulfate process titanium dioxide waste acid, most free sulfuric acid and impurity ions in the sulfate process titanium dioxide waste acid are removed firstly through the core steps of diffusion dialysis and extraction and / or adsorption, so that a subsequent extraction / adsorption system is converted into a low-acid and low-impurity environment from a high-acid and high-impurity environment, and the titanium recovery and all-component recycling co-processing method in the sulfate process titanium dioxide waste acid is realized. According to the method, the recovery rate of titanium is increased from less than 1% to more than 80%, the efficient recovery of titanium is realized, the recovery of sulfuric acid is realized, high-purity ferric hydroxide and manganese hydroxide products (the recovery rates are both greater than 70%) are produced, and the efficient recycling of waste acid is really realized.

The application provides a method for preparing a magnetic heterostructure material of magnetite-graphene and application of the magnetic heterostructure material in a directional heat-conducting composite material, and belongs to the technical field of composite materials. The method comprises the following steps: (1) slowly adding a sodium hydroxide solution into a ferric chloride solution under water bath condition to prepare a ferric hydroxide gel, and sequentially performing drying and aging, centrifugation, cleaning and freeze drying on the gel to obtain a ferrous oxide nanocrystal; (2) adding the ferrous oxide nanocrystal, graphene and dopamine hydrochloride into a Tris buffer solution and fully stirring, and performing multiple centrifugation, cleaning and freeze drying to obtain ferrous oxide-dopamine-graphene; and (3) performing calcination reduction on the ferrous oxide-dopamine-graphene to obtain the magnetic heterostructure material of magnetite-graphene. The magnetic heterostructure material prepared by the method can be applied to the preparation of the directional heat-conducting composite material as a heat-conducting filler, and has the advantages of high operability, low cost and the like.

The invention discloses a method for recycling iron phosphate and graphite from residues obtained after valuable metal is extracted from waste lithium battery black powder. The method comprises the following steps: carrying out alkali solution reaction on ferrophosphorus residues obtained after lithium is extracted from lithium iron phosphate black powder, so that elements such as phosphorus, aluminum and titanium are all dissolved in a liquid phase, and the iron element generates ferric hydroxide which is left in alkali-soluble residues; the alkali-soluble residues are soaked in an ammonia complexing solution to remove impurities such as copper and nickel, and then are neutralized by an acid solution with relatively low concentration to obtain an iron salt solution and graphite carbon residues; oxidizing roasting, flotation, purification and drying are carried out on graphite carbon residues, negative electrode carbon residues obtained after valuable metal is extracted from waste ternary lithium battery black powder after optional preliminary purification, and graphite carbon residues obtained after lithium and ferrophosphorus are extracted from current lithium iron phosphate black powder, so that graphite can be recycled; and acid is added into the alkali dissolution filtrate to adjust the pH value to 6.0-9.0, and then the temperature is raised to hydrolyze impurity salts such as aluminum, titanium and chromium dissolved out of the phosphate solution to form hydroxides and metatitanic acid precipitates to be removed, so that finally, the quality of the iron phosphate prepared by the method disclosed by the invention is ensured to reach related standards.

The invention discloses a titanium white waste acid treatment process, and relates to the technical field of industrial waste regeneration. The titanium white waste acid is subjected to microfiltration and membrane electrolysis treatment, sulfuric acid is separated and recycled under the control of constant pressure and constant current, and residual liquid is subjected to electrodialysis treatment to oxidize ferrous ions into ferric hydroxide precipitates and calcined into ferric oxide; carrying out reduction leaching on the titanium-containing material, hydrolyzing to generate metatitanic acid, and calcining to obtain titanium dioxide; oxidizing the hydrolysate to precipitate vanadate, and calcining to obtain vanadium pentoxide; adjusting the pH value of the filtrate, selectively adsorbing scandium through a biological adsorption column, precipitating and calcining the eluent to obtain scandium oxide, and regenerating and recycling the adsorbent through acid pickling. According to the process, through multi-stage treatment and biological adsorption, resource recycling of sulfuric acid, iron, titanium, vanadium and scandium components in the waste acid is achieved, the process is clean and efficient, secondary pollution of a traditional process is avoided, and a green low-carbon solution is provided for waste acid treatment in the titanium dioxide industry.

This invention provides a one-dimensional silver nanostructure / metal hydroxide composite material, its preparation method, and its application. The preparation method includes: adding a one-dimensional silver nanostructure, a metal salt, and an additive to a solvent and stirring to disperse them evenly; adding an acidic or alkaline reagent under stirring conditions to adjust the pH of the solution, causing the metal ions in the solution to convert into metal hydroxide precipitates, obtaining a one-dimensional silver nanostructure-metal hydroxide suspension; then performing solid-liquid separation, washing and drying the obtained solid product to obtain a one-dimensional silver nanostructure / metal hydroxide composite powder; wherein the metal hydroxide is aluminum hydroxide, zinc hydroxide, magnesium hydroxide, iron hydroxide, manganese hydroxide, copper hydroxide, nickel hydroxide, or cobalt hydroxide, and the one-dimensional silver nanostructure is silver nanowire or silver nanoribbon. The resulting composite material uses metal hydroxide as a carrier and separator, inhibiting the drying and agglomeration of silver nanowires from the source, exhibiting high conductivity and good redispersibility, thus improving conductivity.

The invention discloses a treatment method of ferric hydroxide-based iron-manganese slag. The treatment method comprises the following steps: roasting the iron-manganese slag in a reducing atmosphere; carrying out wet magnetic separation on the roasted slag in a magnetic field to obtain iron powder and non-magnetic slag; carrying out oxidation impurity removal on the non-magnetic slag; carrying out manganese leaching on the non-magnetic slag subjected to oxidation impurity removal to obtain manganese carbonate and waste liquid; and recycling the waste liquid. According to the scheme provided by the invention, the iron-manganese slag is subjected to roasting, magnetic separation, oxidation impurity removal, manganese leaching, waste liquid recycling and the like, so that all-component high-value utilization of the iron-manganese slag is realized.

The invention belongs to the technical field of waste resource utilization, and provides a separation method for valuable metals in an acid leaching solution. After the pH value of the acid leaching solution is adjusted to be alkaline, the obtained alkaline solution is mixed with gas containing carbon dioxide in a spraying or aeration mode for reaction. According to the method, magnesium ions and aluminum ions in the acid leaching solution are converted into basic carbonate and calcium ions are converted into carbonate by utilizing carbon dioxide and liquid caustic soda; compared with hydroxide, basic carbonate and carbonate cannot adsorb lithium ions and rare earth ions in an acid leaching solution, ferric hydroxide formed by a small amount of iron ions has limited adsorption on the lithium ions, and efficient separation and recovery of the lithium ions can be achieved. Furthermore, the carbon dioxide-containing gas is carbon dioxide-containing tail gas, and the separation method can utilize the carbon dioxide gas in the tail gas, so that the carbon emission is reduced.

The invention discloses a method and system for synchronously removing nitrate nitrogen in wastewater and hydrogen sulfide in biogas based on iron circulation, and belongs to the technical field of industrial sewage treatment and biogas purification. According to the invention, iron ions are used as a medium to construct a closed cycle, and biogas and wastewater are synchronously purified; the method comprises the following steps: oxidizing hydrogen sulfide in biogas by using a ferric sulfate solution to generate ferrous sulfide, elemental sulfur and sulfuric acid; then sulfuric acid is separated from a mixture of ferrous sulfide and elemental sulfur through solid-liquid separation, then the ferrous sulfide and the elemental sulfur are subjected to autotrophic denitrification with nitrate in the wastewater under the action of thiobacillus denitrificans, and ferric hydroxide, nitrogen and sulfate are generated; and then the ferric hydroxide reacts with the separated sulfuric acid to regenerate a ferric sulfate solution which is reused in the desulfurization step. In the whole process, cyclic utilization of iron ions is achieved, hydrogen sulfide and nitrate nitrogen are synchronously converted into harmless nitrogen, elemental sulfur and sulfate, and the purposes of treating waste with waste and recycling resources are achieved.

The application discloses a recycling method of NF3 electrolysis residual solution and relates to the technical field of electrolysis residual solution recycling treatment. The method comprises the following steps: step 1: removing Fe ions in the electrolysis residual solution; first, hydrogen peroxide or oxygen is added into the electrolysis residual solution to oxidize the divalent iron ions into trivalent iron ions, and then ammonia water and sodium hydroxide or ammonium hydrogen carbonate and sodium hydroxide are added into the solution to react, so that the trivalent iron ions are precipitated in the form of iron hydroxide; step 2: the electrolyte solution after the removal of iron is adjusted to a pH of 3-12 by adding hydrofluoric acid, enters an extraction system, extracts the nickel element in the ammonium hydrogen fluoride, and purifies the ammonium hydrogen fluoride; and step 3: the nickel element separated from the electrolyte solution enters a second extraction to synthesize a nickel sulfate product.

The invention discloses a potassium ferrate bottom-oriented enrichment slow-release agent and a preparation method and application thereof, and belongs to the technical field of bottom-oriented enrichment slow-release agents, and the preparation method comprises the following steps: S1, adding polyethylene glycol into water glass, dissolving, adding lithium hydroxide, acidifying, aging, washing, drying, grinding and calcining to obtain a modified carrier; s2, adding a potassium hydroxide solid into the hypochlorous acid solution, adding ferric hydroxide, continuously adding the potassium hydroxide solid, stirring at constant temperature, reacting to obtain a black purple solution, cooling, filtering and drying to obtain a potassium ferrate crude product; s3, adding the potassium ferrate crude product in the S2 into a 3M potassium hydroxide solution for dissolving, adding the modified carrier in the S1, stirring under an ultrasonic condition, then adding a potassium hydroxide solid to be saturated, keeping the temperature, standing, carrying out suction filtration, cleaning a filter cake, and drying to obtain a composite material; s4, grinding and sieving the composite material obtained in S3, mixing with a bottom enrichment agent, and tabletting to obtain a potassium ferrate bottom enrichment slow-release agent; the pond substrate can be improved.

This invention provides high-purity ferric citrate that is substantially free of β-iron hydroxide. [Solution] A high-purity ferric citrate that substantially does not contain β-iron hydroxide, and in which the β-iron hydroxide content is less than 6% by weight relative to its total weight. Preferably, high-purity ferric citrate having a β-iron hydroxide content of less than 2.5% by weight. More preferably, high-purity citric acid II having a β-iron oxide content of less than 1.0% by weight. iron.

The application discloses a kind of full solid waste mine repair soil and preparation method thereof, it is related to soil repair technical field, the full solid waste mine repair soil includes the following weight content of raw material composition: titanium gypsum 50~80%, converter steel slag 15~30%, titanium extraction tailings 5~15%, sintering machine head ash 0~5%.In the application, titanium gypsum contains fine-grained calcium sulfate dihydrate, iron hydroxide, etc., has good water retention effect;Converter steel slag contains P, can provide phosphorus fertilizer effect for soil, and the alkalinity of steel slag can adjust the acidity and alkalinity of soil;Secondly, steel slag and titanium extraction tailings jointly act, play the role of solidifying soil and preventing water and soil loss;The pozzolanic activity of titanium extraction tailings is good, and forms strength matrix with steel slag, can solidify soil;Sintering machine head ash contains K, can provide potassium fertilizer effect for soil.

The invention provides a preparation method of 1, 1, 2, 3-tetrachloropropene, which comprises the following steps: dehydrating a dehydrochlorination product of pentachloropropane and then isomerizing, and using cheap anhydrous ferric trichloride as a catalyst; filtering an isomerization product, adding quenching liquid, stirring, mixing and quenching; filtering, layering, washing with water, removing water, removing light components and rectifying to obtain a 1, 1, 2, 3-tetrachloropropene product; the technical scheme provided by the invention is suitable for continuous treatment operation, can solve the inherent defects of a supported catalyst, does not need to replace the catalyst or stop, and can run throughout the year; a small amount of ferric chloride in the isomerization reaction liquid with most of the catalyst filtered out is converted into flocculent ferric hydroxide through quenching liquid, a small amount of tar generated in the isomerization reaction liquid is adsorbed through the flocculation effect of aluminum hydroxide and ferric hydroxide, and the isomerization reaction liquid is further purified; no side reaction is generated in the light component removal rectification process, so that the problem that the yield is influenced due to the increase of the tar content can be thoroughly solved.

The application relates to the technical field of purification devices, in particular to a purification and recovery device for ferroelectric flocculation sewage and a purification method thereof. The device comprises a cylinder, a reaction zone, an alkalization zone, a mixing zone and an aeration zone are sequentially arranged in the cylinder from top to bottom and are mutually separated, the reaction zone and the alkalization zone are in communication, a first valve is arranged at the communication position of the reaction zone and the alkalization zone, when in use, a first electrode group and sodium sulfate are used to build an environment of oxygen deficiency and alkalinity in the reaction zone, and cuprous oxide and iron hydroxide flocculation precipitate are generated when the complex is broken; a second electrode group and sodium sulfate in the alkalization zone enhance the alkalinity, free monovalent copper in water is completely combined into cuprous oxide precipitate, free copper ions and precipitate are generated in the aeration zone, an electromagnet attracts the ferromagnetic precipitate, and finally, free copper ions are adsorbed by electrodes in an electric adsorption box, the precipitates after reaction in the zones are transferred by gravity and are independently treated, the cost is low, and the efficiency is high.

A method for processing of phosphate compounds comprises providing (S10) of a primary liquid being an acid solution comprising at least phosphorous. Phosphate compounds comprising iron are precipitated (S20) from the primary liquid by adding (S22) a first additive material to the primary liquid. The first additive material comprises iron hydroxide and a solid filter-aid material. First solid matter, comprising the precipitated phosphate compounds and the solid filter-aid material is separated (S28) by a first filtering. The separated first solid matter is exposed (S30) for an alkaline solution, causing a dissolution (S32) of phosphate compounds and precipitation (S32) of iron hydroxide, which gives a secondary liquid. Second solid matter comprising the precipitated iron hydroxide and the solid filter-aid material is removed (S38) by a second filtering. Part of the second solid matter is recycled (S40) as the first additive material. A system for processing of phosphate compounds is also disclosed.

The invention provides an electro-Fenton and membrane separation cooperative treatment method for PVA waste liquid. The electro-Fenton and membrane separation cooperative treatment method comprises the steps of PVA waste liquid preparation, PVA waste liquid pretreatment, PVA waste liquid deep degradation, membrane separation concentration, persulfate regeneration and the like. Compared with the prior art, the method has the advantages that the PVA material is used as the raw material to prepare the waste liquid, dual strong oxidizing free radicals are generated through electro-Fenton and membrane separation synergistic treatment and the synergistic effect of persulfate and electro-Fenton, the PVA degradation efficiency is greatly improved, the minimum COD after treatment can reach 30 mg / L or below and is far superior to that of a traditional Fenton method (COD is smaller than 100 mg / L), ferrous ions are not added in the whole treatment process, and the method is environmentally friendly. And the insoluble electrode is adopted, so that flocculates such as ferric hydroxide mud and the like and precipitates are prevented from being generated.

The present application relates to the technical field of aquaculture, and particularly relates to a denitrification agent for aquaculture and a preparation method thereof, which comprises the following raw materials in 100% by weight: modified polymeric ferric sulfate 24-26%, iron hydroxide 36-38%, polymeric aluminum ferric silicate 1.5-2%, calcium supplement 3-3.5%, and the rest is maifanite powder. The denitrification agent has a good water improvement effect, and can effectively remove pathogenic bacteria in water for a long time.

This invention discloses a composite catalyst, its preparation method, and its application in sludge treatment, belonging to the field of sludge treatment and environmental protection technology. The invention synthesizes an iron-carbon nanocomposite catalyst using ferric nitrate nonahydrate, antibiotic bacterial residue, and melamine as precursors. The resulting catalyst can, on the one hand, activate ammonium persulfate to generate free radicals that disrupt the water-locking structure of the sludge, enhancing its hydrophobicity and thus improving dewatering efficiency. On the other hand, the Fe species in the composite catalyst activates ammonium persulfate to form Fe... 3+ Fe 3+ The hydrolysis generates ferric hydroxide colloids that can adsorb sludge particles, neutralize surface charges, thereby reducing interparticle repulsion, promoting floc aggregation, and enhancing dewatering efficiency. The advanced oxidation process of ammonium persulfate catalyzed by iron-carbon nanocomposite catalysts also achieves the removal of antibiotic resistance genes from sludge.

The application discloses a preparation method of battery-grade iron phosphate, which comprises the following steps: (1) preparing iron hydroxide powder and phosphoric acid; (2) diluting the phosphoric acid into a phosphoric acid solution by using deionized water, and then stirring the iron hydroxide and the phosphoric acid solution in a reactor; (3) after sufficient stirring, a catalyst is added, and a dispersing agent and a crystal transformation inducer are added within 30-40 minutes after the reaction starts, and the reaction is heated; (4) after the heating reaction is completed, the precipitate is separated out, and then the separated precipitate is washed and dried, and after drying, the precipitate is crushed and screened, so as to obtain the prepared iron phosphate. The preparation method is simple and easy to implement, does not need a large number of equipment and a complex technological process, can be used for large-scale production, has good economic benefits, and can meet the use requirements in the field of new energy batteries, and the prepared product is stable in quality, excellent in quality, and can be prepared in a short time.

The invention discloses a reinforcing method for realizing self-flocculation settling separation of tailings based on flue gas desulfurization, and belongs to the green and environment-friendly technical field of solid waste recycling and flue gas treatment. The method comprises the following steps: carrying out size mixing on iron tailings obtained through physical separation, then introducing roasting or steel smelting flue gas into ore pulp for desulfurization, and meanwhile, heating the ore pulp exposed in the air by utilizing flue gas waste heat, so that alkaline minerals in the ore pulp are converted into sulfate crystals; the method comprises the following steps of: oxidizing and hydrolyzing Fe < 2 + > in ore pulp to generate amorphous iron hydroxide gel and multi-core hydroxyl iron complex gel, so as to obtain an ore pulp system with self-flocculation capacity, and directly adding the ore pulp system into a thickening tank for settling separation of tailings. According to the invention, a closed-loop technical method of gas-solid separation and solid-liquid separation is constructed, the tailing slurry is used as a desulfurizing agent to complete flue gas purification and separation, and the internal biomass generated in the process is utilized to strengthen tailing settling separation, so that a brand new technical path is opened up for bulk and high-value utilization of iron tailings.

This invention belongs to the field of flow battery energy storage technology, and relates to a negative electrode electrolyte for alkaline all-iron flow batteries and its preparation method. The negative electrode electrolyte is prepared from iron salts, a complexing agent, a promoting component, an alkaline component, an auxiliary electrolyte, and water. The total iron concentration is 0.1–2.0 mol / L, the molar ratio of the complexing agent to the iron salt is 1.5–4, the molar ratio of the promoting component to Fe is 0.05–1.0, the alkaline component concentration is 2.0–6.0 mol / L, and the auxiliary electrolyte concentration is 0–2.0 mol / L. The negative electrode electrolyte of this invention for alkaline all-iron flow batteries has a high total iron concentration, which not only avoids the precipitation of elemental iron during charging and discharging, but also effectively prevents the formation of ferric hydroxide precipitate, improves the stability of iron ions, and greatly extends the cycle life of the negative electrode electrolyte. It can be widely used in aqueous alkaline all-iron flow batteries.

In order to simply and efficiently treat nitrogen dioxide in cement exhaust gas and reduce environmental burden by a method for producing ammonium nitrate, the present invention comprises: a nitrogen dioxide recovery step for bringing nitrogen dioxide in cement exhaust gas into contact with water to form a liquid containing NOx; a reduction reaction step in which ammonia is generated by bringing a reducing catalyst into contact with the NOx-containing liquid; an ammonia recovery step in which the ammonia is gasified using the waste heat gas; a solid-liquid separation step in which the remaining part after ammonia recovery is subjected to solid-liquid separation and iron hydroxide is separated from the remaining part of NOx that is not used; a neutralization step for producing ammonium nitrate by bringing the separated liquid containing nitrate nitrogen and / or nitrite nitrogen and the separated liquid containing NOx into contact with ammonia recovered by gasification; and a catalyst production step in which the magnetite used in the reduction reaction step is obtained by reacting ferric sulfate with an aqueous sodium hydroxide solution and performing solid-liquid separation, and the aqueous sodium sulfate solution during the solid-liquid separation is separated into sodium hydroxide and sulfuric acid by electrodialysis, the sodium hydroxide is recycled in the preparation of the magnetite.

A method for purifying acidic wastewater from a mining process, the method comprising pretreating (12) the acidic wastewater to obtain pretreated wastewater (16), providing a water purification apparatus (30) comprising an electrolytic cell (14) comprising a substantially vertical tube connected to a source of electric power (13) and comprising one or more first electrode(s) (2) comprising one or more iron and / or aluminum electrode(s), and one or more inert second electrode(s) (4), and a substantially vertical separator tower (20) arranged in a flow connection with the electrolytic cell, applying the pretreated wastewater (16) to the electrolytic cell (14), operating the electrolytic cell (14) to produce iron hydroxide and / or aluminum hydroxide (3) acting as molecular sieve capable of trapping impurities, such as comprising sulphates and any remaining solids, and to produce hydrogen causing the molecular sieve with the trapped impurities to raise in the vertical tube as an accumulating floc, conveying the raising floc into the separator tower (20), wherein the floc (5, 19) is separated by expelling from the top of the separator tower (15), and obtaining first purified water (W1) from the separator tower (20) from below the raising floc. A water purification apparatus (30) and use of the water purification apparatus.

The application relates to the field of road materials, in particular to a grass-inhibiting and soil-stabilizing lime-soil-stone mixed material for field roads and a construction method thereof. The grass-inhibiting and soil-stabilizing lime-soil-stone mixed material for field roads comprises the following components in parts by weight: lime 8-12 parts, clay 20-25 parts, crushed stone 50-60 parts, fly ash 15-20 parts, silica ash 5-8 parts, ferric chloride 2-3 parts and water 12-18 parts. The application can inhibit the growth of weeds and improve the overall strength of the mixed material by adding ferric chloride and silica ash and the cooperation of other components, wherein the ferric chloride can inhibit the enzyme activity of root systems by releasing iron ions, and can generate iron hydroxide colloid to wrap weed seeds and block the oxygen required for germination; the silica ash can continuously release hydroxyl ions to maintain alkalinity and improve the material density to compress the growth space of weed roots.

The invention discloses a process method for producing zinc oxide by recovering zinc from waste galvanized steel sheets. The process method comprises the following steps: step 01, carrying out corrosion reaction on galvanized steel sheet wastes and acid liquor; 02, reacting the liquid with a hydrogen peroxide solution; step 03, injecting a sodium hydroxide solution into the liquid; step 04, filtering the liquid to obtain a ferric hydroxide flocculate precipitate; and step 05, filtering impurities in selective chelating adsorption resin to obtain a zinc-containing solution. Step 06, adding a sodium hydroxide solution into the zinc-containing solution to obtain a sodium metazincate solution; step 07, filtering the sodium metazincate solution, and introducing carbon dioxide gas into the obtained filtrate to obtain a sodium bicarbonate solution; and step 08, carrying out centrifugal separation on the solution, and calcining the obtained solid to obtain zinc oxide. According to the method, the zinc is effectively extracted by adopting the waste galvanized steel as the raw material, and the economic benefit of treating the waste galvanized steel is improved.

A method for producing ammonium nitrate includes a nitrogen dioxide recovery step of bringing nitrogen dioxide in a cement exhaust gas into contact with water to obtain an NOx-containing solution, a reduction reaction step of producing ammonia by bringing a reducing catalyst into contact with the NOx-containing solution, an ammonia recovery step of vaporizing the ammonia with a waste heat gas, a solid-liquid separation step of separating a residue after the ammonia recovery into iron hydroxide and an unused residue of NOx, a neutralization step of bringing the separated nitrate / nitrite nitrogen-containing solution and the NOx-containing solution into contact with the ammonia vaporized and recovered to prepare ammonium nitrate, and a catalyst production step in which magnetite used in the reduction reaction step is obtained by reacting iron sulfate with a sodium hydroxide aqueous solution and separating the mixture into solid and liquid, the sodium sulfate aqueous solution in the solid-liquid separation is separated into sodium hydroxide and sulfuric acid by electrodialysis, and the sodium hydroxide is used in a circulatory manner for preparing the magnetite, where the nitrogen dioxide in the cement exhaust gas is treated simply and efficiently while reducing environmental burden.

The invention belongs to the technical field of asbestos tailing utilization, and particularly discloses an asbestos tailing full-resource utilization process. The method provided by the invention comprises the following steps: crushing and sieving asbestos tailings, adding a sulfating roasting reagent and ammonium bisulfate to obtain a mixed material, and roasting the mixed material in a fluidized bed; after heat preservation treatment, water is added for a leaching reaction, and leaching residues and filtrate are obtained through solid-liquid separation; adjusting the pH value of the filtrate to obtain a mixed precipitate of ferric hydroxide and nickel hydroxide and a sulfate solution, performing evaporative crystallization on the sulfate solution, and performing roasting treatment to obtain a mixed oxide; and adding aluminum powder into the mixed oxide, and carrying out aluminothermic reduction reaction to obtain the magnesium ingot. According to the method, high-valued utilization of various elements in the asbestos tailings can be achieved, circular economy and closed-loop utilization can also be achieved, and the economic effect of enterprises is improved.