85results about "Zinc sulates" patented technology

The invention provides a process for recovering various valuable elements such as lead, zinc, silver and potassium from soot of a steel mill. The process comprises the following steps of water leaching, fluorine removal, high-temperature concentration, primary cooling crystallization, secondary cooling crystallization, secondary leaching, ammonia leaching and ammonia distillation. According to the recovery process, potassium in the soot of the steel mill is recovered in the form of potassium chloride, zinc is recovered in the form of zinc sulfate, silver is recovered in the form of silver chloride, only auxiliary materials such as sulfuric acid, ammonia water and calcium chloride which are low in price are used in the whole recovery process, the cost is low, no waste water or waste residues are generated in the whole process, the direct recovery rate of lead and zinc is 95% or above, and the production cost is low. The direct recovery rate of silver is 98% or above, and the method has practical application value.

The utility model discloses a zinc sulfate purification device and belongs to the technical field of zinc sulfate purification. Comprising a reaction kettle, an upper pressing plate and a lower pressing plate, the upper pressing plate is horizontally arranged in the reaction kettle and is in sliding sealing with the inner wall of the reaction kettle, the upper pressing plate moves up and down in the reaction kettle through a first driving mechanism, and the lower pressing plate is horizontally arranged in the reaction kettle and is in sliding sealing with the inner wall of the reaction kettle; the lower pressing plate moves up and down in the reaction kettle through a driving mechanism II; the upper pressing plate drives the plurality of paddles to rotate, so that the paddles stir a zinc sulfate solution, the reaction of zinc powder and the zinc sulfate solution is accelerated, the upper pressing plate moves downwards to be close to the lower pressing plate, and the upper pressing plate and the lower pressing plate are matched to crush precipitated purification residues and release zinc powder in the precipitated residues. And then the upper pressing plate and the lower pressing plate are separated, the upper pressing plate rotates, the rotating blades rotate, all the zinc powder plays a role, and waste of the zinc powder is avoided.

The invention provides a collaborative recovery method for directionally converting SO2 into waste tire cord steel wires, and belongs to the technical field of solid waste recycling. According to the collaborative recovery method provided by the invention, the granular waste tire cord steel is roasted in an SO2 / O2 / N2 mixed atmosphere and an air atmosphere in sequence, and then the valuable metal components copper, zinc and iron in the waste tire cord steel wire are directionally converted into copper sulfate, zinc sulfate and iron oxide through further leaching and magnetic separation processes. According to the method, efficient recovery and resource utilization of valuable metal components of copper, zinc and iron in the waste tire cord steel wires are achieved, an innovative solution is provided for high-value utilization of the waste tire cord steel wires, and the method has good application prospects and social and ecological benefits.

The invention belongs to the field of wastewater treatment, and particularly relates to a selective separation method for zinc and cadmium in a low-concentration-difference difficult-to-separate zinc-cadmium-containing solution, which comprises the following steps: carrying out co-precipitation reaction on the low-concentration-difference difficult-to-separate zinc-cadmium-containing solution and an alkaline precipitator to obtain co-precipitation slag enriched with zinc and cadmium; the low-concentration-difference difficult-to-separate zinc-cadmium-containing solution is a solution in which the ratio of the concentration of high-concentration ions to the concentration of low-concentration ions in zinc and cadmium is 0.9-2; the concentration of cadmium is 8-40g / L; the coprecipitation slag is subjected to size mixing with water, selective cadmium dissolving is carried out under the condition that the pH of size obtained after size mixing is controlled to be 6-7.1, then solid-liquid separation is carried out, and zinc-rich slag and cadmium-rich leachate are obtained; the solid-to-liquid ratio in the slurry is 85-150g / L; carrying out deep zinc removal treatment on the cadmium-rich leachate to obtain a cadmium purification solution, and preparing the cadmium purification solution into a high-purity cadmium product with the grade of 3N or above; and the zinc-rich slag is subjected to acid leaching and deep cadmium removal treatment, a zinc purification solution is obtained, and then the zinc purification solution is prepared into a 2N-grade high-purity zinc product. According to the method disclosed by the invention, high-quality cadmium and zinc can be obtained at high yield.

The invention discloses a system and method for treating metallurgical dust and sludge and ferric sulfate slag through a rotary kiln, and the system comprises the rotary kiln which is used for carrying out pelletizing forming, pre-reduction desulfurization and deep reduction on the metallurgical dust and sludge and sulfuric acid slag of an iron and steel plant; the rotary kiln is sequentially provided with a pelletizing section, a pre-reduction desulfurization section, a deep reduction section and a discharging section from the kiln tail to the kiln head, and an inclined check ring is arranged in the pelletizing section; the kiln head of the rotary kiln is provided with an air nozzle, and the kiln tail is provided with a smoke outlet. The surface cooler is used for cooling the rotary kiln flue gas from the rotary kiln to obtain low-temperature flue gas; the zinc sulfate preparation module is used for treating the low-temperature flue gas and preparing a zinc sulfate product. According to the method, resource utilization and high-value utilization of the metallurgical dust sludge and the sulfuric-acid slag of the iron and steel plant can be achieved, low-sulfur and high-iron metallized pellets and zinc sulfate products are produced, and comprehensive utilization of iron, zinc and sulfur in the metallurgical dust sludge and the sulfuric-acid slag is achieved.

The utility model discloses a sulfuric acid leaching kettle which comprises a barrel body, a flat cover is connected to the upper end of the barrel body, a stirring device is connected to the center of the flat cover, a stirring shaft of the stirring device is arranged at the center of the interior of the barrel body, and a bottom supporting seat is arranged at the bottom of the barrel body; a cleaning device is arranged below the bottom supporting base, and a discharging port is formed in the center of the bottom of the barrel. The utility model has the advantages that the cleaning device synchronously rotates along with the stirring shaft, so that sediments at the bottom of the kettle can be conveniently and timely cleaned; the spraying holes of the spraying ring spray corresponding media into the equipment so as to eliminate foam above the liquid level or absorb corresponding gas or impurities through spraying liquid, and meanwhile, cleaning media can be sprayed through the spraying holes so as to clean the tank wall and part of the stirring shaft in real time.

The utility model discloses a harmless treatment device for ion exchange resin production waste liquid, which comprises a multi-effect evaporator, a separation device, an activated carbon adsorption reaction kettle, a filter press, a zinc sulfate synthesis reaction kettle and a centrifugal separation reaction kettle, an evaporation residual liquid outlet of the multi-effect evaporator is connected with an activated carbon adsorption reaction kettle, the activated carbon adsorption reaction kettle is connected with an activated carbon inlet, an outlet of the activated carbon adsorption reaction kettle is connected with a filter press, and a filtrate outlet of the filter press is connected with a zinc sulfate synthesis reaction kettle. The zinc sulfate synthesis reaction kettle is connected with a zinc oxide inlet, and an outlet of the zinc sulfate synthesis reaction kettle is connected with a centrifugal separation reaction kettle. According to the device, organic matters in the resin waste liquid are removed to obtain relatively pure sulfuric acid, and an industrial zinc sulfate product is obtained through subsequent utilization of the sulfuric acid, so that resource utilization of the waste liquid is realized.

The application discloses a method for deeply removing organic matters in zinc sulfate solution, and belongs to the technical field of zinc hydrometallurgy. An oxidizing agent is added into the zinc sulfate solution, and the adding amount is 13-18 g / L; the solution is stirred and oxidized at 80-85 DEG C for 5-5.5 h. A neutralizing agent is added into the oxidized solution to increase the pH value of the solution to 5-5.5, and a solid-containing suspension is obtained by stirring. A flocculating agent is added into the solid-containing suspension, and the adding amount is 1-1.5 g / L; after stirring for 50-70 min, solid-liquid separation is carried out, and supernatant is obtained. An adsorbent is added into the supernatant, and the adding amount is 2.5-3.5 g / L; after stirring at 75-85 DEG C for 100-150 min, solid-liquid separation is carried out, and the purified zinc sulfate solution after removal of organic matters is obtained. The method adopts the synergistic treatment of oxidation, neutralization and co-precipitation, flocculation and adsorption, and can reduce the content of organic matters in the solution to below 80 mg / L through step-by-step conversion and directional removal of the organic matters, and the removal rate of the organic matters reaches more than 51%, so that the deep removal of the organic matters is successfully realized.

This invention discloses a method for producing sulfate from waste acid wastewater, relating to the field of industrial wastewater reuse technology. The method includes the following steps: raw material pretreatment: collecting waste acid wastewater generated from the washing process of non-ferrous metal smelting flue gas, and concentrating it to obtain concentrated acid water; slurrying and leaching: mixing materials containing metal oxides with the concentrated acid water in a certain proportion, and carrying out slurrying and leaching reactions; purification: purifying the leached solution to obtain a purified solution; sulfate preparation: treating the purified solution to obtain a solid sulfate product. This method directly uses waste acid to replace expensive purchased sulfuric acid, significantly reducing the production cost of sulfate. It is particularly suitable when sulfuric acid market prices are high. Conventionally, producing one ton of zinc sulfate consumes 0.43 tons of sulfuric acid, and producing one ton of manganese sulfate consumes 1.23 tons of sulfuric acid. Using this method, sulfuric acid is directly replaced, resulting in significant cost savings.

The invention relates to a method for recovering germanium in germanium distillation raffinate and carrying out gradient purification and impurity removal, belongs to the technical field of germanium distillation raffinate resource recovery, and aims at the characteristics that impurity ions in the germanium distillation raffinate are high in concentration, and germanium and impurities are difficult to effectively separate due to similar properties. Short-process efficient and high-purity productization recovery of germanium in the germanium distillation residual liquid is realized by adopting a pretreatment-ion exchange-chlorination distillation technical route, and comprehensive recovery and resource utilization of lead, chlorine, zinc and the like in the germanium distillation residual liquid are realized by adopting an acidification lead precipitation-negative pressure distillation-neutralization impurity removal technical route. According to the method, the high-purity GeCl4 product is directly extracted and produced from the germanium-containing wastewater by adopting chemical modification and ion exchange methods, and compared with the existing process, the method has the technical advantages of high comprehensive utilization rate, short-range high efficiency, greenness, cleanness and the like.

The invention discloses an intermittent feeding device for zinc sulfate production, and belongs to the technical field of chemical equipment, the intermittent feeding device comprises an acid leaching tank module, a zinc powder quantification module and a zinc powder distribution module, the acid leaching tank module is provided with the zinc powder quantification module, and the zinc powder quantification module is used for quantitatively weighing a zinc raw material needing to react; the acid leaching tank module is arranged in the acid leaching tank body and is used for feeding a zinc raw material into an inner cavity of the acid leaching tank body to react with a sulfuric acid component, and the zinc powder distribution module is arranged in the inner cavity of the acid leaching tank body and is used for continuously adding a small amount of the zinc raw material into the sulfuric acid component to react. Quantitative zinc raw materials can be uniformly conveyed into sulfuric acid components for reaction, zinc sulfate crystal shells are prevented from being formed on the surface of powder during excessive feeding, further proceeding of the reaction is inhibited, and yield reduction caused by incomplete reaction is avoided.

This invention provides a method for the synergistic recovery of sulfuric acid and copper and zinc from waste acid from copper strip washing, comprising the following steps: S1, waste acid pretreatment; S2, novel bipolar membrane electrodialysis separation; S3, copper-targeted precipitation separation: adding a copper-targeted precipitant to the heavy metal concentrate to form a stable precipitate, followed by filtration and washing to obtain a copper-enriched precipitate; S4, zinc sulfate preparation: adjusting the pH of the filtrate after copper precipitation separation and removing reducing impurities, then evaporating and concentrating to a solution density of 1.4-1.5 g / cm³, cooling and crystallizing, and centrifuging to obtain zinc sulfate crystals, with the mother liquor returned to the evaporation and concentration unit for recycling. This method can achieve efficient recovery and recycling of sulfuric acid, while simultaneously achieving precise separation of copper and zinc ions and the preparation of high-value products, significantly improving the resource utilization efficiency of waste acid and reducing treatment costs.

The invention discloses a method for dechlorinating a zinc sulfate solution, the method for dechlorinating the zinc sulfate solution comprises a pretreatment step and a main reaction step, and the method specifically comprises the following steps: adjusting the pH value of the zinc sulfate solution to be treated to 1.5-3.5 to obtain a material a; adding a precipitator into the material a for stirring reaction to obtain a dechlorinated zinc sulfate solution; the precipitant is trialkyl bismuth, trialkyl antimony, trialkyl lead or trialkyl vanadium. According to the method, the chlorine removal efficiency and stability are improved by regulating and controlling reaction conditions such as the pH value, the temperature and the types of precipitants, and finally, an environment-friendly, economical and feasible treatment scheme is realized.

The invention provides a method for preparing high-purity zinc sulfate from side-blown converter copper smelting smoke dust, and relates to the technical field of smoke gas recovery, and the method comprises the following steps: S1, water leaching; s2, replacing and depositing copper; s3, neutralizing, oxidizing and removing arsenic; s4, neutralizing to remove iron, and adding a calcium hydroxide solution (20% water suspension) to obtain ferric hydroxide; s5, replacing and precipitating cadmium, adding 1.2 times of zinc powder into the neutralized liquid according to the content of cadmium, reacting for 2-3 hours at the temperature of 60-80 DEG C, and performing solid-liquid separation to obtain sponge cadmium; and S6, after cadmium removal, adding the filtrate into a concentration kettle for evaporation and concentration, feeding the prepared concentrated material into a centrifugal machine for centrifugal separation, returning the separated liquid to the concentration kettle, and carrying out flash evaporation sieving treatment on the separated solid at 180 DEG C to prepare zinc sulfate powder. The purity of the zinc sulfate product is high, and the requirements of different fields for high-quality zinc sulfate can be met.

The invention discloses a ZnO / ZnS / ZnSO4 nano composite material and a gas sensor based on the ZnO / ZnS / ZnSO4 nano composite material, a ZnO / ZnS heterojunction composite material with rough spherical morphology is prepared by adopting a two-step method, part of ZnS in the ZnO / ZnS heterojunction composite material can be converted into ZnSO4 through subsequent controllable annealing treatment, so that a ZnO / ZnS / ZnSO4 three-layer composite material is obtained, and finally the ZnO / ZnS / ZnSO4 three-layer composite material is prepared into the gas sensor. And high-performance detection of NO2 gas is realized. The prepared sensor has the characteristics of high sensitivity, good selectivity and strong stability, has relatively high response (65) to 5 ppm NO2 at a relatively low working temperature (110 DEG C), can detect nitrogen dioxide gas with extremely low concentration, and has huge potential in the aspect of developing and detecting low-concentration nitrogen dioxide gas.

The utility model discloses a vacuum concentration device for preparing zinc sulfate heptahydrate, which comprises a reaction kettle, a heating jacket is arranged in the reaction kettle, two sides of the heating jacket are respectively connected with a steam input pipe and a steam output pipe, the inner wall of the reaction kettle is fixedly connected with a flow dividing pipe, the flow dividing pipe is of a lantern ring structure, and the bottom of the flow dividing pipe is connected with a spray head. Two groups of nozzles are arranged at the bottom of the shunt pipe, the two groups of nozzles are annularly distributed at equal intervals relative to the bottom of the shunt pipe, one side of the shunt pipe is connected with a first connecting pipe, the first connecting pipe is provided with a first electromagnetic valve and a water pump, and one side of the first connecting pipe is connected with a second connecting pipe; an air pump and a second electromagnetic valve are arranged on the second connecting pipe, and an online densimeter and a temperature sensor are arranged on one side of the reaction kettle. According to the device, the cleaning difficulty of the inner wall of the reaction kettle can be reduced, and meanwhile, the concentration of zinc sulfate heptahydrate can be monitored, so that the concentration quality of zinc sulfate heptahydrate is ensured.

This invention proposes a method for preparing zinc sulfate heptahydrate through spatially induced directional crystallization via a zinc-substrate rolled structure. The method involves rolling zinc sheets into zinc coils, utilizing the geometric constraints between the zinc coil layers in conjunction with the high-speed shearing of the reaction liquid to guide seed crystals to grow along a specific direction, yielding high-purity, uniformly morphologically uniform ZnSO4·7H2O crystals. This method achieves ultra-low impurity residue while exhibiting breakthrough structural stability, with a product purity reaching 99.99%. Environmental testing shows that the material retains over 98% of its initial performance during long-term use, successfully solving the stability problems caused by lattice distortion, impurity residue, and industrial scale-up in traditional processes, providing a reliable guarantee for high-end material applications.

The invention discloses a deep impurity removal method for waste tire pyrolysis carbon black, and belongs to the technical field of upgrading purification and high-value utilization of waste tires and waste rubber pyrolysis carbon black. The deep impurity removal method comprises the following steps: mixing oxidized waste tire pyrolysis carbon black with an oxidant solution, carrying out desalination treatment, and filtering to obtain a first filtrate and a first carbon black product; adding zinc into the first filtrate, and filtering after the reaction is completed to obtain unreacted zinc and second filtrate; carrying out heat treatment on the first carbon black product under the action of protective gas, and condensing gas flow to obtain sublimed sulfur and a second carbon black product; and reselecting the second carbon black product to obtain a pure carbon black product and silicon dioxide tailings. On the basis of density difference between silica particles and carbon particles in oxidized waste tire pyrolysis carbon black, silica and carbon are separated by using a heavy liquid separation method after oxidation leaching desalination, so that the purposes of ash reduction and purification are achieved.

The invention discloses a method for removing calcium and magnesium ions in a zinc sulfate solution and prolonging the working time of an evaporator. The method comprises the following steps: mixing and reacting a zinc sulfate solution, zinc fluoride and an alkaline zinc-containing substance, and filtering to obtain the zinc sulfate solution. According to the method provided by the invention, the content of calcium ions and magnesium ions in the zinc sulfate solution can be effectively reduced, other cation impurities are not introduced, the content of fluorine ions in the zinc sulfate solution can be controlled, and corrosion of the fluorine ions to a pipeline is avoided.

The invention relates to a method for removing elemental sulfur in zinc sulfate leachate, and relates to the technical field of lead and zinc smelting. The invention provides a method for removing elemental sulfur in zinc sulfate leachate, which comprises the following steps: adding copper sulfate into the zinc sulfate leachate to form a mixed solution, adding cadmium powder into the mixed solution to form a mixed slurry, reacting the mixed slurry, and carrying out liquid-solid separation after the reaction is finished to obtain a desulfurized zinc sulfate solution. According to the method, the coupling agent copper sulfate and the inducer cadmium powder are added into the zinc sulfate lixivium, the impurity elemental sulfur in the zinc sulfate lixivium is removed, and the purposes of purifying the zinc sulfate solution and eliminating the influence of the elemental sulfur are achieved. The removal method disclosed by the invention is simple and easy to operate, the removal rate of elemental sulfur reaches 97%, and the original production process flow is not influenced.

This invention discloses a method for recovering tin and indium from lead ore refining waste. The method involves mixing lead ore refining waste with limestone and crushed coal, then smelting it in a side-blown furnace under oxygen-enriched air conditions. After cooling the collected slag, sulfuric acid solution and sodium dodecyl sulfate are added, and the mixture is ground to obtain slag powder. The slag powder is then leached with acid, filtered, and separated to obtain filtrate A and filter residue B. Filter residue B is dried, pulverized, and smelted to recover crude tin. Filtrate A is then treated with sodium sulfite and stirred, followed by the addition of calcium carbonate to adjust the pH to 4.5–5.5 and stirring. Filtrate A is then filtered to obtain filtrate C and filter residue D. Filter residue D is leached a second time with acid to obtain a leachate. Zinc powder is added to the leachate for displacement to recover crude indium. The displacement solution is collected, and filtrate C is mixed with it to prepare zinc sulfate. This method improves the recovery efficiency of tin and indium from refining waste and is beneficial for the recycling of lead ore refining waste.

The utility model discloses an evaporative crystallization production device of zinc sulfate monohydrate. The evaporative crystallization production device comprises a preheating unit, a double-effect evaporation concentration crystallization unit, a separation unit, a condensate water unit and a vacuum unit which are connected in sequence, wherein the preheating unit is used for recovering system condensate water waste heat, the double-effect evaporation, concentration and crystallization unit is used for concentrating a zinc sulfate solution and growing and enriching crystals, the separation unit is used for separating zinc sulfate monohydrate from the solution, the condensate water unit is used for collecting evaporation condensate water, and the vacuum unit is used for controlling evaporation vacuum degree; the evaporation section adopts a double-effect countercurrent process, so that the crystallization temperature of zinc sulfate monohydrate is ensured, the steam consumption is saved, the device is more energy-saving and environment-friendly, and meanwhile, the device is simple in process flow, easy to implement, high in automation degree and low in operation cost, meets the requirements of sustainable development, and can be widely applied to the actual industrial production process.

An electrochemical element comprising: - an aqueous electrolyte with a pH less than 7 containing Zn2+ and Mn2+ ions, - a negative electrode comprising zinc or a zinc-based alloy, - a positive electrode comprising manganese dioxide, a first carbon black with a specific surface area S1, and a second carbon black with a specific surface area S2, with S2 / S1 ≥ 2. Abbreviated figure: Figure 1

The present application relates to a method for treating a zinc-containing residue. The treatment method comprises: performing alkali washing on a zinc-containing residue to obtain ammonia gas and an alkali washing slurry; performing solid-liquid separation on the alkali washing slurry to obtain a filter cake and a filtrate; sequentially performing washing and acid leaching on the filter cake to obtain a zinc sulfate solution and an aluminum residue; sequentially performing washing and alkali leaching on the aluminum residue to obtain an alkali leaching solution and an alkali-leached residue; performing electrolysis on the alkali leaching solution to obtain zinc and an aluminum-containing alkali solution; and performing aluminum removal treatment on the aluminum-containing alkali solution to obtain a composite defluorinating agent composed of aluminum oxide and calcium oxide and a regenerated alkali solution. The treatment method provided by the present application can realize the separation and resource recycling of aluminum, zinc, chlorine, and ammonia from a zinc-containing residue and the regeneration and recycling of an alkali solution, and the treatment process does not involve secondary waste, has low treatment energy consumption, and has economy and industrial feasibility.

The application discloses a zinc sulfate evaporation device, which comprises an evaporator body and a shell, wherein a cavity is arranged between the shell and the evaporator body, an air inlet pipe is arranged at the upper end of the shell, an air pressure adjusting device is arranged in the cavity, the air pressure adjusting device comprises a moving block, a baffle, a spring, an upper slide rail and a lower slide rail, the moving block slides left and right between the upper slide rail and the lower slide rail, the baffle is used for dividing the cavity into a first cavity and a second cavity, a connecting pipe is arranged at the upper end of the shell, the first cavity and the second cavity are communicated with each other through the connecting pipe, and an air inlet is arranged on the upper and lower surfaces of the upper slide rail. The air pressure adjusting device can dynamically adjust the opening and closing of the air inlet according to the air pressure difference between the first cavity and the second cavity, so that the inflow amount of hot air is controlled, and the effective evaporation of the zinc sulfate liquid is ensured.

The invention relates to the related technical field of zinc sulfate production, in particular to a novel impurity removing and filtering device for zinc sulfate production, which comprises a support base, a stirring and filtering mechanism is arranged on the inner side of a mixing cylinder, a curing mechanism is arranged on the inner side surface of a curing cylinder, and a cooling and vibrating mechanism is arranged on the inner side surface of a discharge pipe. In the stirring and filtering mechanism, stirring blades promote full reaction of zinc blocks and zinc sulfate, a filtering plate and a filtering membrane doubly filter impurities, a dirt removing block automatically cleans filtering holes, efficient filtering is ensured, and the maintenance cost is reduced; in the curing mechanism, an arc-shaped guide plate and a heating rod enable the solution to be uniformly heated, zinc sulfate crystallization is facilitated, scraping blocks and scraping plates maintain heat transfer efficiency, and the service life of equipment is prolonged; the cooling vibration mechanism prevents caking through a refrigeration pipe, a vibration disc is matched with sieve holes to loosen caking and screen particles, the product granularity uniformity is guaranteed, and the zinc sulfate production quality and efficiency are integrally improved.

The invention relates to a method for recovering HCl and zinc sulfate from zinc and germanium-containing concentrate chlorination distillation residual liquid, which comprises the following steps: filtering distillation residues from the residual liquid, placing the residual liquid in a distillation kettle, adding concentrated sulfuric acid with the mass of more than or equal to 95% at the speed of 10-30mL / min, heating to 100 + / -10 DEG C, and carrying out a reaction of replacing hydrochloric acid with sulfuric acid to enable HCl gas and GeCl4 gas to escape, generating mixed replacement residual liquid containing sulfuric acid and zinc sulfate and calcium sulfate replacement residues; cooling escaped gas through a two-stage water-cooled snakelike coil pipe, obtaining hydrochloric acid of about 6N and GeCl4 liquid at the bottom at the first-stage cooling temperature of 60 + / -10 DEG C, obtaining hydrochloric acid of more than 7N at the second-stage cooling temperature of 30 + / -10 DEG C, leaching waste gas through clear water or dilute alkali liquor, and emptying; and filtering the sulfuric acid replacement hydrochloric acid residual liquid, feeding the obtained sulfuric acid and zinc sulfate mixed solution to a zinc hydrometallurgy system to recover sulfuric acid and zinc sulfate, and washing and drying calcium sulfate filter residues to obtain a gypsum product. According to the method, efficient recovery of HCl, zinc sulfate, gypsum and germanium tetrachloride is achieved, and zero discharge of waste liquid is achieved.

The invention relates to a method for recovering valuable metals in cobalt slag through ultrasonic strengthening, and belongs to the technical field of hydrometallurgy. According to the method, the cobalt slag produced in the zinc hydrometallurgy purification process is used as a raw material, two-step leaching is conducted on the cobalt slag under the ultrasonic wave condition, the first-step sulfuric acid concentration is 1.5-2.5 mol / L, and the second-step sulfuric acid concentration is 1, 5-2.0 mol / L. Compared with a traditional cobalt slag leaching method, the using amount of a reducing agent is reduced by 40%-50%, the reaction time is shortened to be within 50%, and the method is suitable for industrial production. According to the method, the high leaching rate of valuable metal in the cobalt slag is achieved under the normal pressure and the low temperature, and the slag amount is reduced by 24%-31%. By means of the method, segmented leaching of iron, zinc, cobalt and manganese is achieved, the obtained first-segment leaching solution does not contain manganese basically, and the technical problem that manganese and zinc need to be further separated from the leaching solution is solved; and iron in the cobalt slag is basically completely leached in the first step, so that the influence of iron on cobalt leaching is effectively avoided or reduced.

Provided herein is a method for producing furfural from lignocellulosic biomass or an extract thereof, such as a sugar-rich extract, using a solid zinc sulfate-rich catalyst to catalyze the conversion to furfural. Also provided herein are zinc sulfate-rich catalysts, and methods for producing zinc sulfate and zinc sulfate-rich catalysts from tire carbon black.

The invention discloses a pretreatment method for evaporating and crystallizing zinc sulfate in arsenic precipitation post-liquid, which comprises the following steps: carrying out acid leaching on zinc smelting smoke dust to obtain leachate; zinc oxide is added into the leachate to adjust the initial pH value of the leachate to 1-2, then ferrous sulfate heptahydrate is added, oxygen is introduced, oxidation arsenic precipitation is conducted, and liquid obtained after arsenic precipitation is obtained; adding zinc oxide into the arsenic-precipitated liquid to adjust the pH value to 4-6, and neutralizing and purifying to obtain a neutralized and purified liquid; and carrying out evaporative crystallization on the neutralized and purified liquid to obtain a zinc sulfate heptahydrate product. According to the method, the pH value of the leachate is adjusted in a gradient mode, oxygen oxidation and a specific additive ratio are combined, efficient precipitation of arsenic is achieved, and then residual arsenic, iron, copper and other impurity elements are removed through further neutralization; in the whole process, an endogenous regulator is adopted to replace a traditional exogenous chemical agent, introduction of additional impurity elements is avoided, meanwhile, the neutralization slag is converted into a material capable of being directly returned to a pyrogenic copper smelting system to be recycled, and resource recycling is achieved.