80results about How to "Reduce the amount of waste residue" patented technology

The invention relates to a method for preparing high-purity manganese sulfate from a manganese-containing waste liquid. The existing method for treating the high-manganese-containing waste liquid generated in the wet production of cobalt salts mainly comprises a lime precipitation method and a method for preparing manganese sulfate by removing calcium and magnesium via fluoride and adopting a P204 or P507 extracting agent and has the respective problems that the utilization value of prepared manganese hydroxide is low, the fluoride-containing wastewater is polluted and the like. According to the method, heavy metals are removed by virtue of sulfide, manganese is extracted through a Cyanex272 extracting agent, calcium and magnesium are thrown and the reverse extraction is performed to obtain the high-purity manganese sulfate product which can meet the requirement of a ternary cell material on manganese sulfate; and the method has the advantages of short process flow, no fluoride pollution and the like.

The invention provides a new method for extracting a semi-manganese oxide ore to prepare a manganese sulfate solution, belonging to the technical field of manganese ore extraction. The method comprises the following steps: crushing the semi-manganese oxide ore; adding cassava alcohol waste water in a reactor, then adding the semi-manganese oxide ore and sulfuric acid, and adjusting the ore pulp liquid-to-solid ratio to be 3:1-5:1 with water; and stirring at 70-98 DEG C for reaction for 1-6h to obtain the reaction lixivium, wherein the leaching rate of manganese is more than 90%. In the invention, the trade waste, i.e. cassava alcohol waste water is taken as a reducing agent, so that the method changes waste into treasures, has double benefits of environmental protection and economy, and has mild process condition and simple edulcoration process.

The invention discloses a brand new method of producing electrolytic manganese metal. The method comprises the following steps: (1) grinding lean manganese ore powder, adding an anode liquor of electrolytic manganese and then adding the anode liquor of electrolytic manganese to be reacted with sulfuric acid to obtain a reaction leachate; (2) carrying out press filtering on the reaction leachate so as to remove slags, adding SDD (Sodium Dimethyl Dithiocarbamate) to remove impurites, introducing oxygen to oxidize, then adding manganese hydroxide to react, supplementing ammonium water to neutralize, and then adding a vulcanizing agent to further remove impurities; (3) after further carrying out press filtering so as to slags, carrying out deep purification and press filtering so as to remove slags, standing and metering to obtain an electrolyte; (4) electrolyzing the electrolyte to obtain the electrolytic manganese metal, wherein the anode liquor of electrolytic manganese is recycled. The invention further discloses a method of producing electrolytic manganese metal by fully replacing manganese ores by manganese hydroxide. The two methods disclosed by the invention can be used for improving the manganese leaching efficiency, saving the use level of auxiliary materials, lowering the production cost, simplifying the production flow and reducing the amount of waste residues, is free from influence on electrolysis and is mature, simple and practical in process.

The invention discloses a catalytic oxidation method capable of recycling waste residues, which comprises (1) delivering wastewater to be treated into an oxidation reactor, adding an acid to adjust the pH value of the wastewater and adding an oxidizer and ferrous iron ions (Fe<2+>) serving as a catalyst to perform catalytic oxidation reaction; (2) adding an alkali into the wastewater obtained after the completion of the reaction to adjust the pH value of the wastewater, and delivering the wastewater to a settling basin for flocculating setting; (3) after the completion of the settling, discharging supernatant, delivering the settled waste residues into a reduction reactor, adding an acid into the waste residues to adjust the pH value of the waste residues, dissolving the waste residues toform solution containing ferric ion (Fe<3+>), and adding a reducer to reduce the Fe<3+> into Fe<2+> at the same time; and (4) circulating the reduced solution containing the Fe<2+> to an oxidation reactor to use the solution as a catalyst to perform the catalytic oxidation reaction. Compared with the conventional catalytic oxidation, the method reduces the discharge of waste iron residues, reducesthe waste iron residue treatment cost, protects environment, reduces the usage amount of the catalyst in a catalytic oxidation process and saves resources.

The invention relates to a culturing medium and fermentation method for producing erythrocin through fermentation of streptomyces erythreus. A primary seed medium, a secondary seed medium and a fermentation medium for producing erythrocin through fermentation of streptomyces erythreus all contains sucrose and a corn steep liquor. According to the invention, the corn steep liquor, urea, sucrose, and other intermediate-acting carbon sources and nitrogen sources are adopted to substitute original slow-acting carbon sources and nitrogen sources; moreover, the corn steep liquor, urea, and sucrose are soluble in water, so that the viscosity of the fermentation liquor is lowered, the dissolved oxygen is increased, the utilization speed is increased, especially during the later period of fermentation, the solid residue at the end of the fermentation is reduced, the bacteria dregs and the BOD content and the COD contend in the waste water are all greatly reduced, energy-reserving and consumption-lowering are both realized, and the good effects of treatment from the source and clean production are achieved.

The method for preparing lithium carbonate from lepidolite comprises the following steps: take lepidolite (100-500 mesh), add 98% concentrated sulfuric acid in a mass ratio of 1: [0.8-3], stir, and dry step by step to obtain clinker , and crush the clinker into 100-500 mesh, add water to soak, stir, and boil to obtain a mixed solution; centrifuge the mixed solution while it is hot to obtain mother liquor A, cool the mother liquor A in a reaction vessel to 20-80°C, and crystallize Rubidium cesium alum is extracted, and then centrifuged to obtain mother liquor B; the mother liquor B is cooled to -30~20°C in the reaction vessel, potassium alum is crystallized, and then centrifuged to obtain mother liquor C; mother liquor C is neutralized with lye to the pH value After centrifugation, the mother liquor D is obtained, and then the mother liquor D is evaporated and concentrated, and then filtered to obtain the mother liquor E; the mother liquor E is mixed with potassium carbonate or sodium carbonate solution, heated to 80-100°C, and completed under stirring. That is, the crude product of lithium carbonate is prepared, and the crude product is centrifuged, washed and dried to obtain the finished battery grade lithium carbonate. The invention improves the leaching rate of lithium, saves raw materials, generates less slag, and lowers requirements on equipment.

The invention relates to the field of environment protection, in particular to a method for separating and recycling heavy metal in mercury, selenium and arsenic containing dirt acid sludge. The method comprises the steps that firstly waste gas generated by non-ferrous metal metallurgy is washed and settled to obtain dirt acid sludge; then magnesium oxide is added for mixing to obtain mixed sludge; the mixed sludge is sequentially subjected to roasting, acidizing, neutralizing reduction and crystallization operation; and mercury-selenium elementary substances and iron arsenic salt with high purity are sequentially separated and recycled, and meanwhile ammonium magnesium sulfate and other substances with high value can be generated. Compared with the prior art, a good treatment effect on harmful smoke generated in the non-ferrous metal metallurgy process is achieved, heavy metal and sulphur elements in the harmful smoke can be recycled, and resource cyclic reutilization is achieved well; and meanwhile by-products with high value can be generated, and the method can be widely applied to treatment and resource recycling of mercury, selenium and arsenic containing dirt acid sludge in the industry of non-ferrous metal metallurgy.

The invention provides a method for smelting magnesium by a hot method. The method comprises the following steps that: (1) after dolomite and magnesite are calcined by a rotary kiln respectively at a temperature of between 1,150 and 1,200 DEG C, the dolomite and the magnesite are ground into powder with granularity less than 100 meshes, wherein the dolomite comprises the following chemical compositions in percentage by weight: 46 to 47 percent of ignition loss, 19 to 21 percent of MgO, 30 to 33 percent of CaO, and the balance of impurities; the magnesite comprises the following chemical compositions in percentage by weight: 45.2 to 47.2 percent of MgO, 0.2 to 3 percent of CaO, 0.2 to 2.0 percent of SiO2, 50.1 to 52.0 percent of ignition loss, and the balance of impurities; aluminum-silicon alloy is ground into fine powder with granularity less than 100 meshes, wherein the aluminum-silicon alloy comprises the following compositions in percentage by weight: 44 to 50 percent of Al, 45 to 55 percent of Si, and the balance of impurities; and (2) 83 to 86 percent of the calcined dolomite and 14 to 17 percent of the aluminum-silicon alloy fine powder are weighed according to weight percentage, and the mixed materials are made into pellets under the pressure of 20MPa, are filled into a reduction jar, and are reduced for 7 to 9 hours at a reducing temperature of between 1,050 and 1,160 DEG C to produce the magnesium. The method for smelting the magnesium by the hot method has low reduction temperature, small energy consumption and high production efficiency and is environment-friendly.

A method of recycling nickel, cobalt and iron from low-grade laterite-nickel ore includes following steps: (1) performing washing classification to obtain high-silicon and -magnesium ore and low-silicon and -magnesium and high-iron ore; (2) adding enough concentrated sulfuric acid to the high-silicon and -magnesium ore slurry, and performing a reaction at 160-280 DEG C; (3) performing solid-liquid separation to obtain a normal-pressure leached residue and a normal-pressure leached liquid; (4) adding the normal-pressure leached liquid and the low-silicon and -magnesium and high-iron ore slurry according to proportion and performing pressurized leaching to the mixture at 195-240 DEG C; (5) purifying a pressurized-leached filtrate; (6) recycling nickel and / or cobalt through precipitation of sulfides or hydroxides or other recycling methods; and (7) washing the normal-pressure leached residue with a 10% sodium carbonate solution and drying the normal-pressure leached residue to obtain an iron concentrate powder product. The method is wide in adaption range of the laterite, is high in leaching rate of the nickel and the cobalt, is small in normal-pressure leaching device, is short in time and is high in efficiency. The normal-pressure leaching device is a middle-low pressure device, thereby avoiding defects that a high-pressure kettle is high in cost and is liable to scale. The method is quite low in sulfuric acid consumption. The main component, iron, in the ore can be recycled economically and effectively. The method is less in amount of waste residue and can effectively utilize the waste residue.

The invention discloses a method for producing an aluminum ammonium sulfate crystal from an industrial waste (aluminum residue). The method for producing the aluminum ammonium sulfate from aluminum residue comprises the following steps: (1) preparing an aluminum residue slurry from aluminum residue; (2) enabling the aluminum residue slurry to react with concentrated sulfuric acid to generate a crude aluminum sulfate solution; (3) precipitating to separate the crude aluminum sulfate solution; (4) enabling aluminum sulfate to react with aluminum sulfate to generate a crude aluminum ammonium sulfate solution; (5) cooling to crystallize the crude aluminum ammonium sulfate solution; and (6) washing the aluminum ammonium sulfate crystal with water, airing, and packaging to obtain the finished product of aluminum ammonium sulfate. Because aluminum residue is used as the raw material to produce the aluminum ammonium sulfate crystal, the production cost can be reduced. A small amount of aluminum residue is used, but an additional benefit can be achieved. The wastewater can be recycled. The process for producing the aluminum ammonium sulfate crystal is simple, is convenient to operate, is highly safe, is low in production cost, consumes less energy and is suitable of large-scale production.

A new method for recovering nickel, cobalt and iron from low-grade laterite-nickel ore is disclosed. The new method comprises the following steps: washing and grading; carrying out a reaction by adding enough concentrated sulfuric acid into high-silica magnesite ore pulp; carrying out solid-liquid separation to obtain atmospheric pressure leaching residues and an atmospheric pressure leaching agent; adding the atmospheric pressure leaching agent and low-silica magnesite high-iron ore pulp in proportion into a tubular reactor and carrying out pressure leaching at 195-240 DEG C; carrying out solid-liquid separation to obtain pressure leaching residues and a pressure leaching agent; purifying a pressure leaching filtrate and recovering nickel and / or cobalt by precipitation of sulfide or hydroxide or other recovery methods; and washing the pressure leaching residues by the use of a 10% soda ash solution and drying to obtain a fine iron powder product. The method has advantages as follows: wide application range of lateritic ore; high Ni-Co leaching rate; small atmospheric pressure leaching equipment; short time; high efficiency; and low sulfuric acid consumption. As the middle and low pressure tubular reactor is adopted for pressure leaching, the defect that autoclave equipment is expensive and easy to scale is avoided. The main component of ore, iron, can be recovered economically and effectively. The amount of waste residues is low, and the waste residues can be utilized effectively.

The invention discloses a method of recycling nickel, cobalt, iron and silicon from low-grade laterite nickel ore through a combined leaching process. The method includes the following steps: (a) performing washing classification to the low-grade laterite nickel ore to obtain high-silicon and -magenisum ore and low-silicon and -magenisum and high-iron ore; (b) adding heated high-silicon and -magenisum ore slurry and concentrated sulfuric acid into a double-screw material-pushing reactor; (c) dissolving reaction materials in water and performing solid-liquid separation and filter residue washing to obtain a normal-pressure leached residue, a normal-pressure leached liquid and a washing liquid; (d) performing pressurized leaching to the low-silicon and -magenisum and high-iron ore slurry and the normal-pressure leached liquid in a pressurized pot, wherein the Fe<3+> in the normal-pressure leached liquid is hydrolyzed to release acid for leaching the low-silicon and -magenisum and high-iron ore slurry again; (e) decreasing the temperature and performing the solid-liquid separation to obtain a pressurized leached residue and a pressurized leached liquid; (f) removing non-nickel and -cobalt impurities from the pressurized leached liquid, and recycling the nickel and / or the cobalt through a known method; (g) washing the pressurized leached residue through a sodium carbonate solution and washing the pressurized leached residue to obtain iron fine powder; and (h) screening the normal-pressure leached residue to obtain silicon dioxide and fine sand. The method is high in leaching rate of nickel and cobalt, is less in acid consumption and can effectively recycle iron and partial silicon.

The invention relates to a calcium removing method of wastewater. The method comprises the following steps: charging gas into wastewater by an aeration method to take CO2 gas away from the wastewater; and crystallizing and separating calcium ions out of the wastewater in form of solid calcium salt. According to the technical scheme, the calcium removing method of the wastewater does not need any chemical agent, so that secondary pollution can be avoided; only calcium contained in the water mass is separated out, and additional precipitate is avoided.

This invention discloses a method for extracting SiO2 and Al2O3 from fly ashes. The method comprises: activating fly ashes, leaching with more than 40 wt. % NaOH solution so that Si is stripped out in the form of sodium cilicate, introducing CO2 to prepare SiO2, adding CaO or CaCO3 into the leaching residue, calcining to obtain a clinker, preparing Al2O3 by Bayer method, and preparing cement from the waste residue. The method extracts Si at first, thus increasing the Al / Si ratio in the leaching residue. Treated leaching residue can be directly subjected to Bayer method to extract Al2O3, which largely simplify Al2O3 extraction process and increase Al2O3 utility. The method has such advantages as simple process, low investment, and high product added value.

The invention discloses a method for recovering nickel, cobalt, iron and silicon from laterite-nickel ore by a combined leaching process. The method comprises the following steps: adding muck ore slurry and concentrated sulfuric acid after heating into a double-spiral material pushing reactor; dissolving reaction materials in water, then performing solid-liquid separation, and washing filtration residues to obtain normal-pressure leaching residues, a normal-pressure leaching solution and a washing solution; preparing limonite ore slurry from the washing solution and limonite, adding the limonite ore slurry and the normal-pressure leaching solution into a pressurization kettle for pressurization and leaching, hydrolyzing Fe<3+> in the normal-pressure leaching solution to a hematite precipitate, and releasing acid to re-leach the limonite; reducing the temperature, and performing solid-liquid separation to obtain pressurized leaching residues and a pressurized leaching solution; removing non-nickel and cobalt impurities in the pressurized leaching solution, and then recovering nickel and / or cobalt by an existing method; washing the pressurized leaching residues with a soda ash solution, and then drying to obtain fine iron powder; and performing screening treatment on the normal-pressure leaching residues to obtain silicon dioxide and fine sand. The method disclosed by the invention has the advantages of short leaching time, high nickel leaching rate, low acid consumption and effective recovery of iron and part of silicon.

The invention relates to a method for preparing ferro-titanium by carbothermic reduction-self-propagating. The method comprises the following steps: (S1) adding ilmenite into pulverized coal or graphite to obtain a pellet; putting the pellet into an inert atmosphere at 1,000-1,200 DEG C for reduction to obtain carbothermic-reduction ilmenite pellet; breaking and grinding the carbothermic-reductionilmenite pellet to obtain carbothermic-reduction ilmenite powder for later use; (S2) uniformly mixing the carbothermic-reduction ilmenite powder obtained in step (S1) with metal aluminum, sodium chlorate, titanium dioxide, calcium oxide and calcium fluoride; (S3) igniting the upper part; after complete reacting, cooling and separating the slag to obtain ferro-titanium. The method provided by theinvention avoids the problems in ferro-titanium separation, reduces the process links, reduces the production cost, effectively removes organic impurities and water in minerals, reduces the consumption of the reducing agent aluminum as well as the slag generation in a ferro-titanium smelting process, and raises the ferro-titanium grade.

The invention discloses a preparing method for high-purity manganese sulfate. The preparing method includes the steps that manganese sulfate monohydrate obtained through high-temperature crystallization is put into a rotary kiln and is burned with methyl alcohol, hydroxyl ions discharged after temperature increment and a burning value are mixed into powder-crystal-shaped manganese sulfate, and magnesium ions, potassium ions and sodium ions are caught and then are coked; the dried and coked magnesium-potassium-sodium mixture is put into a dissolution kettle, deionized water is added, dissolution and filtering are carried out, and un-dissolved substances (coked magnesium-potassium-sodium granules) are separated out; a qualified manganese sulfate solution is sent to a secondary high-temperature crystallizer and crystallized, a manganese sulfate hydrated crystal is obtained, then the product is sent and dried, and the qualified manganese sulfate is obtained. The preparing method is simplein step and easy to operate, the temperature and the pH value are not required to be strictly controlled, a large quantity of high-purity impunity removing medicaments are also not required to be consumed, and through the coking effect and different dissolution degrees of all impurities, the impurities are filtered out and removed out, the impunity removing effect is remarkable, secondary pollution on the environment can be avoided, the production cost is low, and industrialization scale production is easy to achieve.

The invention discloses a preparation method of 1-cyclohexyl-1-phenyl-3-piperidinepropanol hydrochloride. The preparation method comprises the following steps of: dropwise adding chlorocyclohexane and diethyl ether mixed liquid into a magnesium and diethyl ether mixture; keeping warm, and carrying out refluxing reaction for 3 hours to obtain Grignard reaction liquid; and dropwise adding acetophenone into piperidine hydrochloride, anhydrous methanol and formaldehyde mixed liquid at room temperature to react for 30 minutes; cooling and filtering in vacuum to obtain a solid mixture; mixing the solid mixture and diethyl ether, and dropwise adding the Grignard reaction liquid; cooling and then dropwise adding 5% diluted hydrochloric acid; separating; and drying to obtain a product. By using the preparation method of 1-cyclohexyl-1-phenyl-3-piperidinepropanol hydrochloride disclosed by the invention, the yield of a product can reach more than 95%, the production cycle of the product is shortened, the productivity is improved, the labor amount in a production process is reduced, the production cost is reduced, and the market competitiveness is improved.

A waste electric appliance circuit board energy regeneration innocent treatment system comprises a pretreatment device, an alkalization incinerator, a multi-metal and oxide recycling and smoke purifying device, a recycled heat energy generating set and an electrical automatic control device. The pretreatment device is connected with the alkalization incinerator, the alkalization incinerator is connected with the multi-metal and oxide recycling and smoke purifying device and the recycled heat energy generating set, and the electrical automatic control device is connected with the pretreatment device, the alkalization incinerator, the multi-metal and oxide recycling and smoke purifying device and the recycled heat energy generating set. The technological devices are relatively simple, accurate in treatment, low in investment, low in operation power consumption and low in operation cost due to water utilization treatment; by means of the devices, resources can be fully utilized, and secondary pollution is avoided.

The invention provides a method for leaching calcium and strontium by using low concentration hydrochloric acid to chemically separate Weishan Lake rare earth concentrate. The method comprises the following steps: immersing the Weishan Lake rare earth concentrate in the low concentration hydrochloric acid, and heating the obtained solution to perform a reaction; adding the Weishan Lake rare earthconcentrate to a filtered leachate, heating the obtained solution to perform a reaction, carrying out solid-liquid separation, discharging the obtained liquid, and reusing the obtained solid phase. The grade of the Weishan Lake rare earth concentrate is improved to 50% from 40%, 90% of calcium carbonate and 85% of strontium carbonate in the Weishan Lake rare earth concentrate are efficiently leached out, the rare earth loss rate of below 1% is ensured, a discharged acid leaching waste liquid only contains calcium chloride, strontium chloride and a small amount of iron chloride, and wastewatertreatment is easy.

The invention discloses a method for recovering nickel, cobalt, iron and silicon from a laterite-nickel ore through a united leaching technology. The method comprises the following steps: adding heated saprolite ore pulp and a concentrated sulfuric acid to a double-helix shoving reactor; dissolving reaction materials into water, performing solid-liquid separation, washing filter residues so as to obtain constant-pressure leached residues, constant-pressure leached liquor and washing liquor; making the washing liquor and the limonite into limonite pulp, heating the limonite pulp and the constant-pressure leached liquor respectively, adding the limonite pulp and the constant-pressure leached liquor which are heated in a pressurized pipeline reactor to be pressurized and leached, hydrolyzing Fe<3+> in the constant-pressure leached liquor so as to release the acid, and then leaching the limonite; lowering the temperature for solid-liquid separation so as to obtain pressurized and leached residues and pressurized and leached liquor; removing impurities which do not belong to the nickel and the cobalt from the pressurized and leached liquor, and recovering the nickel and / or the cobalt by an existing method; washing the pressurized and leached residues through a sodium carbonate solution, and drying the washed pressurized and leached residues so as to obtain powdered iron; sieving and processing the constant-pressure leached residues so as to obtain silicon dioxide and building sand. The method disclosed by the invention has the advantages that the leaching time is short, the leaching efficiency of the nickel is high, the acid consumption is low, and the iron and part of the silicon can be effectively recovered.

The invention discloses a water washing stone and a processing method for the water washing stone. The water washing stone prepared from environment-friendly materials is harmless in waste water and waste residue, free of peculiar smell and small in waste residue amount, and has the excellent environment-friendly characteristic; and the prepared water washing stone has the characteristics of wear resistance, high reusability, low comprehensive cost and simplicity and convenience in use.

The invention discloses a method for reducing waste residues of an N,N'-dicyclohexylcarbodiimide product. The method comprises the following steps: adding potassium carbonate or sodium carbonate intoa crude DCC product in a solvent-free state, controlling a temperature to be 100-120 DEG C, carrying out stirring for 1 hour, controlling a pressure to be less than -0.09 MPa, and performing distilling to obtain qualified DCC. Potassium carbonate or sodium carbonate is added to increase the pH value of a reaction system, and potassium carbonate and sodium carbonate do not react with the product, so the stability of N,N'-dicyclohexylcarbodiimide is facilitated, and the N,N'-dicyclohexylcarbodiimide is prevented from being decomposed at a high temperature; the amount of waste residues produced after DCC distillation can be reduced by 50% and is 1% or less of the mass of the crude DCC product, so environmental protection investment is greatly reduced; the method is simple and reliable to control, and production cost is reduced; and meanwhile, aspotassium carbonate or sodium carbonate is used as a catalyst, the product becomes transparent and colorless from light yellow, so the appearanceof the product is improved.

The invention provides a method for extracting lithium from lithium-contained low-magnesium brine, and relates to the technical field of chemical extraction and chemical engineering. The method comprises the steps that: CaO, water and excessive Na2CO3 are mixed for reaction, and obtained reaction liquid is filtered to obtain alkali solution and a CaCO3 solid; the alkali solution is fed in the lithium-contained low-magnesium brine, the pH of the lithium-contained low-magnesium brine is gradually adjusted above 11, and alkaline magnesium carbonate and Mg(OH)2 precipitate are separated out to obtain lithium-contained brine after removal of magnesium; a composite organic extracting system is adopted to extract lithium from the lithium-contained brine after removal of magnesium to obtain a loaded organic phase and raffinate; the loaded organic phase is mixed with acid water solution; and lithium in the loaded organic phase is reversely extracted to a water phase so as to obtain lithium-contained water solution and a lithium-removed organic phase. The method provided by the invention can extract lithium from the lithium-contained low-magnesium brine, and is high in yield and purity of lithium, low in cost, low in investment and high in material recycling rate.

The invention discloses a reduction leaching method for separating manganese and silver in a manganese silver concentrate, and belongs to the technical field of preparation of manganese sulfate for electrolysis. The reduction leaching method is mainly achieved through the following steps: (1) dissolving a certain amount of sodium metabisulfite into a certain amount of water; and (2) slowly adding the sodium metabisulfite solution into a manganese silver concentrate pulp, stirring and carrying out a reduction reaction in an acidic medium, after completion of the reduction reaction, filtering, carrying out solid-liquid separation, and thus respectively obtaining a manganese-containing solution and a silver-containing ore mud. The subsequent manganese leached solution is subjected to deep purification and impurity removal to prepare a pure manganese sulfate solution, and the sliver-enriched residue is subjected to silver extraction by an ammoniacal thiosulfate method. The selected reducing agent has strong reducibility, the reaction required temperature is low, the output waste residue amount is small, the reaction time is short, the purification and impurity removal cost of the manganese leached solution is low, requirements on equipment are low, and the reaction process is controllable. The clear, environmental-protection and high-efficiency production process is provided for comprehensive utilization of manganese silver ore resources in China.

The invention discloses a method for recovering nickel, cobalt, iron and silicon from low-grade laterite-nickel ore by a combined leaching process. The method comprises the following steps: washing and grading the low-grade laterite-nickel ore to obtain high-silicon magnesium ore and low-silicon magnesium and high-iron ore; adding high-silicon magnesium ore slurry after heating and concentrated sulfuric acid into a double-spiral material pushing reactor; dissolving reaction materials in water, then performing solid-liquid separation, and washing filtration residues to obtain normal-pressure leaching residues, a normal-pressure leaching solution and a washing solution; respectively heating low-silicon magnesium and high-iron ore slurry and the normal-pressure leaching solution, then adding into a pressurization pipeline reactor for pressurization and leaching, hydrolyzing Fe<3+> in the normal-pressure leaching solution to release acid, and re-leaching the low-silicon magnesium and high-iron ore; reducing the temperature, and performing solid-liquid separation to obtain pressurized leaching residues and a pressurized leaching solution; removing impurities in the pressurized leaching solution, and then recovering nickel and / or cobalt; washing the pressurized leaching residues with a soda ash solution, and then drying to obtain fine iron powder; and performing treatment on the normal-pressure leaching residues to obtain silicon dioxide and fine sand. The method disclosed by the invention has the advantages of short leaching time, high nickel leaching rate, low acid consumption and effective recovery of iron and part of silicon.

The invention discloses a method for decomposing high-grade mixture rare earth concentrate through low-temperature roasting pretreatment of concentrated sulfuric acid. The method is mainly characterized in that the high-grade mixture rare earth concentrate and the concentrated sulfuric acid are mixed in a certain proportion and are then placed in a steel stirrer to react in advance for a period oftime, and then low-temperature roasting is conducted to obtain concentrated sulfuric acid roasted ore; the concentrated sulfuric acid roasted ore and a certain proportion of H2O are mixed and then leached, so that aqueous leaching liquor and aqueous leaching residues are obtained, the aqueous leaching residues are washed with water to obtain aqueous washing residues and aqueous washing liquor, and the aqueous washing liquor is returned to continue to be used for water leaching of the concentrated sulfuric acid roasted ore; ammonium bicarbonate and diesel are added into the aqueous leaching liquor to obtain carbonic acid rare earth; and the carbonic acid rare earth reacts with hydrochloric acid to obtain acid leaching liquor, and the pH of the acid leaching liquor is regulated with ammonium hydroxide, so that ferrum-thorium residues and a qualified RECl3 solution are obtained. The low-temperature roasting method is adopted so that the ferrum-thorium residues can be economically and reasonably used.

The invention relates to a reduced-injection standardized discharge method for high-sulfur wastewater in oil and gas fields. The method includes the following steps: 1) removing majority of H2S in the high-sulfur wastewater through negative pressure desulfurization; 2) performing chemical reaction to residual H2S in the water generated through the negative pressure desulfurization to form precipitates; 3) performing flocculating settlement to the water generated through the chemical reaction desulfurization; 4) filtering the water generated by the flocculating settlement through a ceramic membrane filtration unit; 5) separating and concentrating the water generated through the ceramic membrane filtration in a high-effective electro-dialysis unit; and 6) performing ozone catalytic oxidization to the fresh water generated through the high-effective electro-dialysis, and discharging the water, which meets the standards, after the ozone catalytic oxidization. By means of the reduced-injection standardized discharge method, sulfides, suspension solids, organic matters, chlorides and oil in the high-sulfur wastewater are deeply removed, and the sulfur content, suspension solid content and oil content of eletro-dialyzed concentrated water satisfy standard of reinjection water of oil and gas fields. The water outputted after the ozone catalytic oxidization meets the standard and is discharged.