403 results about "Arsenic" patented technology

The invention discloses a smelting wastewater trace arsenic real-time monitoring method based on an electrochemical sensing array, and relates to the technical field of electrochemical detection.The method comprises the steps that bypass sample flow is established through a peristaltic pump and pre-filtered, and stable sample flow is obtained; the sample flow is divided into a first passage and a second passage, and a form distinguishing sample flow is obtained after oxidation setting and medium equalization; performing short-time adsorption equilibrium to obtain an interface state parameter set, executing multi-segment coded deposition control based on the parameter set, and collecting a dissolution current curve; a dissolution signal set is obtained by applying single-frequency perturbation signals, characteristic peak parameters are extracted and subjected to correlation calculation with a multi-section response matrix, the total arsenic concentration and the pentavalent arsenic concentration are calculated through a weighted inversion algorithm, and a confidence interval is obtained; and calculating the concentration of the trivalent arsenic and determining an uncertainty range according to the two. According to the method, the quality judgment result is linked with the dynamic adjustment of the sampling flow, the potential amplitude and the deposition duration, so that the self-adaptive optimization control of the detection process is realized.

The present application belongs to the technical field of gaseous arsenic adsorption, and particularly relates to a sulfur-tolerant gaseous arsenic adsorption material, a preparation method and application thereof. Manganese oxide and an iron source are mixed and placed in a ball mill jar, then the ball mill jar is sealed, argon is filled into the jar, and the iron-modified manganese oxide adsorption material is obtained by ball milling. The addition of iron improves the sulfur tolerance of manganese oxide, so that the adsorbent still has high gaseous arsenic adsorption capacity under high-concentration SO2 conditions, and is suitable for the removal of gaseous arsenic in typical high-SO2 flue gas, i.e. non-ferrous smelting flue gas. The preparation method is simple, the cost is low, the gaseous arsenic adsorption capacity is large, and the present application has a wide application prospect.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a pretreatment method for enhancing peroxide to improve the leaching rate of high-sulfur-arsenic gold ore. Comprising the following steps that the high-sulfur-arsenic gold ore is ground and then prepared into ore pulp; an oxidizing agent is added into the ore pulp, oxidation pretreatment is conducted on the high-sulfur-arsenic gold ore under the catalytic action of ultraviolet light, and ore pulp activation liquid is formed; and the pH of the ore pulp activating solution is adjusted to 9-12, a gold leaching agent is added into the ore pulp complexing solution, and stirring gold leaching treatment is conducted. According to the method, efficient oxidation of sulfide and arsenide is achieved under the mild condition through the synergistic effect of photocatalysis and chemical oxidation, the leaching rate of gold is remarkably increased, compared with a conventional peroxide oxidation method for pretreatment, the leaching rate can be increased by 10%-35%, and meanwhile the agent use amount and environmental pollution are reduced.

The invention discloses a preparation method and application of an iron-manganese modified biochar material for remediation of cadmium and arsenic contaminated soil, and relates to the field of new materials.According to the material, rice hull biochar serves as a carrier, and the specific surface area and surface active sites are increased through programmed intermittent ball milling; and the Fe-O / Mn-O bonding modification complex is formed through gradient loading of iron and manganese oxides. The maximum adsorption capacity of the material to Cd < 2 + > and As (V) reaches 71.54 mg.g <-1 > and 49.30 mg.g <-1 > and is 1.65 / 2.53 times that of original biochar, the content of available Cd and As in soil is reduced by 8.98% and 25.2% under the condition that the addition amount is 0.4%, and the passivation efficiency is improved by 1.05 times (Cd) and 9.08 times (As) compared with that of non-ball-milled iron-manganese modified biochar; the material prepared by the method is applied to cadmium and arsenic polluted soil, pollution can be controlled by waste, and the soil can be effectively repaired.

The invention relates to the technical field of geological exploration, in particular to an X-ray fluorescence spectrometer and geological radar combined gold vein rapid positioning method, which comprises the following steps: S1, arranging an exploration survey line in a pre-selected exploration area; s2, along the same measuring line, measuring the content of the gold mineralization indication element in the earth surface or the shallow medium by using an X-ray fluorescence spectrometer, synchronously recording the position information of a measuring point, and generating element content spatial distribution data; the gold mineralization indicating element comprises at least one of arsenic As, antimony Sb and mercury Hg; s3, carrying out detection by using a geological radar along the same measuring line, obtaining a reflected wave signal of an underground medium, synchronously recording position information of a detection point, identifying fault zone and joint zone geological structure anomalous bodies through data processing, and generating geological radar space distribution data; through XRF and GPR data fusion, a CAI quantitative model is established to precisely delineate an ore prospecting target area, a hidden ore body is effectively identified, the exploration precision and efficiency are greatly improved, and the exploration cost is reduced.

The invention relates to the field of metallurgy and chemical engineering, in particular to a heap leaching gold extraction method for low-grade gold sulfide ore. Comprising the following steps that an anti-seepage bottom mat is laid on a dump leaching site; pre-treating the sulfide gold ore by using quick lime; ore crushing; ore is poured and piled on the upper portion of the bottom pad; spraying is conducted on the top of the ore heap and a side slope frame pipe, the gold-containing pregnant solution is collected, and the spraying solution is a sodium cyanide solution; and recovering gold from the gold-containing pregnant solution. According to the heap leaching gold extraction method provided by the invention, the quicklime is adopted to carry out pretreatment (iron removal, desulfurization and arsenic removal) on the sulfide gold ore, and then processes of subsequent ore crushing, heap building, spraying, adsorption and the like are carried out, so that the difficult problems of heap leaching utilization and popularization of low-grade sulfide ore resources are solved.

The application belongs to the technical field of metallurgy, and relates to a method for efficiently purifying and directionally removing oxygen and impurities from a precious antimony alloy, which comprises the following steps: S1, after the precious antimony alloy is melted, an arsenic-tellurium removal agent is added, and smelting is performed at 600-610 DEG C to obtain a pre-impurity removal alloy melt and an arsenic-tellurium residue; the arsenic-tellurium removal agent is a mixture of sodium hydroxide and sodium nitrate; S2, the pre-impurity removal alloy melt obtained in step S1 is heated to 620-640 DEG C, a reducing agent is added, and smelting is performed to obtain an arsenic alkali residue and a refined antimony alloy; the reducing agent is a mixture of antimony sulfide and sodium hydroxide; S3, the arsenic-tellurium residue obtained in step S1 and the arsenic alkali residue obtained in step S2 are ball milled, leaching and filtration are performed to obtain a filtrate and a filter residue; S4, the filtrate obtained in step S3 is mixed with sulfuric acid, and after reaction, a neutralization residue and a neutralization liquid are obtained. By introducing the efficient arsenic-tellurium removal agent and the reducing agent, the content of antimony in the arsenic alkali residue is significantly reduced, and the direct recovery rate of antimony and the recovery rate of tellurium are effectively improved.

The invention discloses an arsenic-containing copper-zinc polymetallic ore beneficiation method and an arsenic-containing mineral inhibitor, and belongs to the field of beneficiation. The arsenic-containing mineral inhibitor comprises the following components by mass percent: 40-60% of lime; 30%-40% of ferrous cyanide salt; and 10%-20% of a sulfomethylation modified tannin extract. The sulfomethylation modified tannin extract is prepared from the following raw materials in percentage by mass: 40-60% of tannin extract; 10-20% of sodium hydroxide; 15 to 25% of formaldehyde; and 5-15% of sulfuric acid. According to the method, the lime, the ferrocyanide and the sulfomethylation modified tannin extract are innovatively compounded according to a specific proportion and are in mutual synergistic interaction, the selectivity of arsenic mineral inhibition can be effectively improved, the agent dosage is reduced, the long-term effect of inhibition is enhanced, deep arsenic reduction can be achieved in the mineral separation process, and the concentrate quality and the recovery rate are improved.

The invention discloses a tellurium copper slag comprehensive treatment technology and a multi-element collaborative recovery method, and relates to the technical field of non-ferrous metal metallurgy and solid waste recycling, and the tellurium copper slag comprehensive treatment technology comprises the following steps: pretreatment and arsenic volatilization removal, selective acid leaching copper extraction, tellurium enrichment through alkaline oxidation, tellurium reduction and arsenic recycling. According to the method, by combining the advantages of a wet process and a pyrogenic process, the defects that in the prior art, arsenic cannot be effectively recycled in the tellurium-copper slag treatment process and the process is complex are overcome, efficient copper and tellurium separation is achieved through coordinated regulation and control of an acid / alkali medium and an oxidizing agent, arsenic is recycled in an industrial raw material form, and the limitation that only tellurium and copper are concerned in a traditional process is broken through.

A group of inventions relates to the field of medical devices. A method for producing needles with adsorption properties is described by depositing an iron oxide coating onto the needle by atomic layer deposition. An acupuncture needle for reflex therapy, consisting of a handle and shaft made of metal material, is placed in a reactor where a vacuum is created at a pressure of approximately 10 mbar ± 0.1 mbar and a temperature of 150 ± 0.2 °C, then a ferrocenecarboxylic acid precursor in the form of vapor is delivered to the reactor, then nitrogen is added to the reactor and degassed to the initial pressure, and this process is repeated in pulse mode until a specific coating thickness is formed. The use of ferrocenecarboxylic acid as a precursor for producing an Fe3O4 coating is described. An acupuncture needle for adsorbing toxic heavy metal ions is described with a coating of Fe3O4 nanofilm thickness of 14 nm ± 0.1 nm, and the nanofilm has the appearance of a nanosieve as shown in Figure 1b. The use of acupuncture needles for adsorbing metal ions is described. The technical achievement of this invention is the development of a method for attaching a magnetic separation film of Fe3O4 to the surface of an acupuncture needle, which is simpler and less expensive in terms of methodology and technique, thereby imparting adsorption properties to the acupuncture needle. The needle of this invention makes it possible to adsorb toxic heavy metal ions such as cadmium, arsenic, manganese, cesium, aluminum, iron, cobalt, nickel, chromium, mercury, lead, copper, zinc, beryllium, antimony, thallium, bismuth, osmium, tin, molybdenum, zirconium, titanium, vanadium, molybdenum, and gallium.

The invention belongs to the technical field of medicine detection, and particularly relates to an ICPMS (Inductively Coupled Plasma Mass Spectrometry) detection method for element impurities in theophylline. The linear test solution, the blank solution and the theophylline test solution are subjected to ICPMS detection, the content of element impurities in the theophylline test solution is calculated according to an internal standard curve method, and the element impurities are one or more of cadmium, lead, arsenic, mercury, cobalt, vanadium, nickel, lithium, antimony or copper. The method is good in reproducibility and stability, high in accuracy and high in precision.

This disclosure relates to a process for removing cadmium and copper, and optionally arsenic, from phosphoric acid solutions typically obtained by wet methods. The process can also allow for the selective and separate recovery of cadmium, copper, and arsenic.

This invention discloses a method for determining the arsenic content in ores, belonging to the field of ore element detection technology, comprising the following steps: (1) weighing the ore sample, adding hydrochloric acid-nitric acid mixed acid for acid hydrolysis, then adding hydrofluoric acid and perchloric acid for auxiliary digestion, evaporating to near dryness, and dissolving the residue with hydrochloric acid; (2) adding a thiourea-ascorbic acid-citric acid mixed reducing masking agent to reduce and mask interfering ions; (3) using an atomic fluorescence spectrometer to determine the fluorescence intensity of arsenic in the sample solution, and calculating the arsenic content according to the standard curve. This method achieves accurate and stable determination of arsenic in various ores such as phosphate rock and iron ore by optimizing sample pretreatment conditions, improving the reduction system and matrix interference suppression strategy.

The application discloses a cooling crystallization device for arsenic leaching solution, which comprises a cooling crystallization tank with a corresponding heat exchange jacket arranged on the periphery, a stirring mechanism comprising a hollow rotating shaft, the middle part of the hollow rotating shaft is connected with corresponding arc-shaped stirring plates through a plurality of material collecting pipes, a crystallization material discharging mechanism comprising a discharging one-way valve installed at the bottom of the hollow rotating shaft, a corresponding blocking push plate is installed in the hollow rotating shaft on the upper side of the material collecting pipe and can be lifted, the blocking push plate is rotationally connected to the end of the piston rod of a corresponding lifting drive oil cylinder through a corresponding connecting shaft, at least one liquid discharging one-way valve for discharging liquid material is installed on the blocking push plate, a corresponding filter screen plate is fixedly connected to the bottom side of the liquid discharging one-way valve, and the opening pressure of the liquid discharging one-way valve is smaller than that of the discharging one-way valve. The application can effectively separate the solid and liquid of part of the crystallized material, and can timely output the crystallization material after the solid-liquid separation.

The invention discloses a process for rapidly removing impurity arsenic in crude antimony by using a refining pot, which comprises the following steps: adding crude antimony produced by a copper removal furnace into the refining pot, melting, then removing slag, blowing oxygen, and adding a proper amount of arsenic removal agent to produce an arsenic-removed antimony alloy; compared with the prior art, the method has the beneficial effects that arsenic in the materials can be rapidly removed, the smelting production efficiency is improved, the production cost is reduced, and conversion of intermediate products is accelerated.

This invention provides a method for removing impurities and recovering nickel anolyte from electrolytic nickel. The method includes the following steps: (1) mixing the electrolytic nickel anolyte with liquid alkali, separating the solid and liquid components to obtain nickel hydroxide and filtrate, evaporating the filtrate to obtain sodium sulfate; mixing the electrolytic nickel anolyte with a nickel source to obtain a mixed solution; (2) mixing the mixed solution with barium salt for lead removal; (3) adjusting the pH of the material obtained after lead removal with nickel hydroxide to obtain an arsenic removal solution, mixing the arsenic removal solution with polyferric sulfate for arsenic removal; (4) mixing the material obtained after arsenic removal with an oxidant to obtain an iron removal solution, performing solid-liquid separation on the iron removal solution to obtain lead-, arsenic-, and iron-removed cathode liquid and iron-containing slag, adding sodium sulfate to the lead-, arsenic-, and iron-removed cathode liquid, and reusing it in the electrolytic nickel process. The method of this invention can efficiently and quickly remove lead, arsenic, and iron from electrolytic nickel anolyte and reuse it.

The invention discloses a high-arsenic hot spring replenishment surface water resource quantity determination method, device and equipment, a medium and a product, and relates to the technical field of water resource evaluation and ecological environment protection. The method comprises the following steps: acquiring information data of a target research area; screening symbolic characteristic parameters of the information data by adopting a statistical analysis method and geochemical diagrams to obtain screened information; based on the law of conservation of mass and the end member mixing theory, a multivariate mixing model is constructed according to the screening information; solving the multivariate mixed model by adopting a least square method to obtain a mixing ratio; the mixing ratio is used for analyzing spatial distribution characteristics of the mixing process of the high-arsenic hot spring and the surface water in combination with water flow path survey information; and determining the replenishment resource quantity of the high-arsenic hot spring according to the mixing proportion. The method aims at improving the accuracy and efficiency of determining the surface water resource quantity supplied by the high-arsenic hot spring.

The invention belongs to the field of valuable metal recovery and arsenic harmless treatment, and particularly relates to a preparation method of crude arsenic. The preparation method of the crude arsenic comprises the following steps: putting an arsenic-containing material into a container of a vacuum distillation device, and sequentially carrying out vacuum distillation and condensation to obtain crude arsenic with the purity of 99% or above in an arsenic condensation area; the arsenic-containing material comprises a high-arsenic alloy; the temperature of vacuum distillation is 470-550 DEG C; and the arsenic condensation area is arranged at a position 40-50mm above the opening of the container. By adopting a vacuum distillation mode, arsenic is volatilized and condensed to a target area (an arsenic condensation area), and other elements are difficult to volatilize or condense to the area. The method is easy to operate, the vacuum distillation temperature is low, and the crude arsenic with the purity being 99% or above can be obtained only through one-time distillation. According to the method, crude arsenic easy to store is prepared while the high-arsenic alloy is treated, subsequent arsenic oxidation is avoided, and the method has the advantages of being environmentally friendly, efficient, high in recovery rate and free of chemical reagent consumption.

The invention discloses a method for recovering copper from high-arsenic matte and enriching arsenic and lead. The method comprises the steps that the high-arsenic matte and quartz sand are fully mixed according to a first set proportion and then added into a smelting furnace; natural gas and oxygen are continuously introduced into the smelting furnace for a heating smelting reaction, air is continuously blown in the heating smelting reaction process, and slag is discharged once every set time; and after slagging is completed, limestone is added to remove arsenic, meanwhile, the temperature in the smelting furnace is gradually increased to 950 DEG C, the temperature in the smelting furnace is kept at 950 DEG C till the content of arsenic in the materials is smaller than 1%, at the moment, arsenic enters smoke, and ash is produced after dust collection. According to the method provided by the invention, the high-arsenic matte obtained through treatment in a lead smelting enterprise can be recycled in a targeted manner, so that lead, antimony, gold, silver, arsenic and the like in the high-arsenic matte are recycled after being classified, and the aims of deeply treating the high-arsenic matte and enriching and extracting various valuable metal elements in a classified manner are fulfilled.

Non-grain-oriented electrical steel sheet, having a thickness of 0.30 mm to 0.38 mm and a composition comprising the following elements, expressed as weight percent: 0.0001% ≤ Carbon ≤ 0.007% 0.09% ≤ Manganese ≤ 0.15% 2.6% ≤ Silicon ≤ 2.95% 0.1% ≤ Aluminum ≤ 0.5% Phosphorus ≤ 0.15% Sulfur ≤ 0.006% Nitrogen ≤ 0.09% 0% ≤ Tin ≤ 0.04% and may contain one or more of the following optional elements: 0% ≤ Niobium ≤ 0.1% 0% ≤ Titanium ≤ 0.1% 0% ≤ Vanadium ≤ 0.1% 0% ≤ Chromium ≤ 1% 0% ≤ Molybdenum ≤ 0.5% 0% ≤ Tungsten ≤ 0.1% 0% ≤ Cobalt ≤ 1% 0% ≤ Arsenic ≤ 0.05% 0.001% ≤ Calcium ≤ 0.01% 0% ≤ Copper ≤ 1% 0% ≤ Nickel ≤ 1% 0% ≤ Boron ≤ 0.05% 0% ≤ Lead ≤ 0.2% 0% ≤ Antimony ≤ 0.2% wherein the remaining composition consists of iron and unavoidable impurities caused by processing, wherein the microstructure of the steel sheet consists of ferrite, comprising 80% to 100% recrystallized microstructure and 0% to 20% non-recrystallized microstructure in area fractions, wherein the average grain size of the recrystallized microstructure is 20 to 110 micrometers, and exhibiting a percentage of eddy current losses in the total iron losses, measured at 1 T and 400 Hz according to standards IEC 60404-2, of 35% to 45%, calculated according to the Bertotti method.

To address the issues of the insolubility of As2O3 and the lack of bioavailability and provide a lyophilized composition comprising arsenic that makes it bioavailable, and further to provide methods for production thereof, and methods for treating malignancies such as tumor or cancer by orally administering the lyophilized composition comprising arsenic.SOLUTION: A method for preparing a lyophilized composition comprising arsenic (LCCA) comprises the steps for: (A) solubilizing As2O3 powder in an aqueous medium to form an As2O3 solution; and (B) lyophilizing the As2O3 solution.SELECTED DRAWING: None

The application discloses a kind of synthesis methods of high-purity electronic grade sodium hypophosphite, dilute phosphine gas is passed into to the mixed solution of sodium hypochlorite and sodium hydroxide that has been pre-cooled with sufficient stirring, and sodium hydroxide is added to carry out reaction;After reaction is completed, filtration, concentration, crystallization, separation are carried out, and the obtained product is purified by resin to obtain high-purity electronic grade sodium hypophosphite product.Compared with the traditional "yellow phosphorus-lime-soda" oxidation-reduction method for preparing industrial grade product and then preparing high-purity electronic grade sodium hypophosphite, the product purification difficulty of the application is low, by using 7N grade ultra-high purity phosphine without any metal impurities, the problem that arsenic, silicon, germanium, nickel, chromium and other metal impurities cannot be completely removed by traditional process can be effectively solved.In addition, the application also has the advantages of effectively solving the problem of three wastes, high recycling rate of by-products, high economy and the like.

This utility model relates to the field of arsenic extraction technology, and more particularly to a pulsed airflow high-purity arsenic extraction device. The technical solution includes a blower, a drying vertical pipe, and a cyclone separator. A base is fixedly connected to the lower surface of the drying vertical pipe. The output end of the blower and the input end of the heater are fixedly connected. The output end of the heater is fixedly connected to the outer surface of the base. A rotating shaft is rotatably mounted on the bottom of the inner wall of the base. Fan blades are fixedly mounted on the outer surface of the rotating shaft, and the fan blades are located inside the base. A screw conveyor is fixedly mounted on the outer surface of the drying vertical pipe near its lower surface. This utility model disperses the arsenic-containing raw material upon entering the drying vertical pipe, allowing for sufficient contact between the raw material and the hot air, improving drying efficiency, facilitating subsequent arsenic purification, and preventing pipe blockage.

The application relates to the technical field of chemical composite materials, and discloses a manganese dioxide-iron oxide composite material for removing arsenic from acidic wastewater and a preparation method, wherein manganese dioxide nanotubes are first synthesized, then the manganese dioxide nanotubes are added into a solution containing iron salt and methyl orange, the black turbid solution is dried in an oven after stirring, and finally the obtained powder is heated and calcined to obtain the manganese dioxide-iron oxide composite material. The composite material can effectively adsorb arsenic in weakly acidic wastewater, and solves the problems of poor arsenic removal effect and poor material stability of single manganese dioxide and single iron oxide. Meanwhile, the composite material has low preparation cost, the preparation method is simple, special equipment is not needed, and a new method for removing arsenic from weakly acidic wastewater is provided.

The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a smelting arsenic-containing wastewater early warning monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring. The application discloses a method for monitoring and early warning of smelting wastewater containing arsenic based on electrical sensing, which effectively improves the resolution and early warning real-time performance of electrical monitoring of arsenic-containing wastewater.

The present invention relates to a method for removing cadmium and copper and optionally arsenic contained in phosphoric acid solutions typically obtained in wet processes. The process also enables selective and separate recovery of cadmium, copper and arsenic.

The invention discloses a smelting arsenic-containing wastewater early warning and monitoring method based on electrical sensing, and relates to the technical field of environmental monitoring, and the method comprises the following steps: arranging electrical sensing arrays in a wastewater discharge pipeline and a sedimentation tank, collecting reference impedance and dielectric response under a pure water condition through constant current excitation, and establishing an electrical baseline model; collecting a voltage signal in real time under a wastewater flowing working condition, comparing the voltage signal with reference impedance in the electrical reference model, and performing standardization processing and Kalman filtering drift compensation to obtain a health correction signal; and based on the health correction signal, constructing a dielectric decoupling matrix to separate multi-ion response, extracting a pure arsenic signal, predicting short-time change through a PSO-BP network, inputting a prediction signal and a flow velocity field into an electricity-flow field collaborative inversion model, solving arsenic ion concentration distribution and diffusion gradient, calculating a risk index in combination with the prediction signal, and generating an early warning grade. According to the invention, the resolution ratio and early warning real-time performance of electrical monitoring of the arsenic-containing wastewater are effectively improved.

The invention discloses a method for comprehensively recovering valuable elements from waste acid, the waste acid contains copper, nickel and arsenic, the concentration of copper in the waste acid is 25g / l-70g / l, the concentration of arsenic in the waste acid is 5g / l-50g / l, the concentration of nickel in the waste acid is 2g / l-25g / l, and the concentration of acid in the waste acid is 70g / l-220g / l, and the method comprises the steps of evaporative crystallization, membrane dialysis, primary neutralization and secondary neutralization. According to the method, the copper recovery rate is not lower than 98%, the nickel recovery rate is not lower than 90%, and the arsenic recovery rate is not lower than 80%. According to the invention, neutralization is carried out after evaporative crystallization and membrane dialysis, so that the alkali consumption can be reduced by 40-60%, and the treatment cost is reduced.

Provided is a method for producing an alkali-free glass substrate having a small number of pinholes. The method is a method for continuously producing an alkali-free glass substrate of the SiO2-Al2O3-RO (RO represents one or more of MgO, CaO, BaO, SrO, and ZnO) system, which includes a step of preparing a raw batch material containing a tin compound and substantially not containing an arsenic compound and an antimony compound; a step of electrically melting the prepared raw batch material in a melting furnace capable of performing electric heating using an electrode; and a step of forming the molten glass into a plate shape by a down-draw method, and the obtained glass has a β-OH value of 0.05 / mm or more and a number of metallic pinholes of 20 / t or less.

This disclosure relates to an arsenic fixation composition and its application method in a coal washing process. The arsenic fixation composition exhibits a good synergistic effect among dolomite powder, auxiliary absorbent, and catalyst, enabling the adsorption of arsenic from the coal washing process products after conversion. This reduces the arsenic content in the coal washing process products and improves arsenic removal efficiency. Using inexpensive, low-cost, and widely available dolomite powder as the main adsorbent reduces environmental pollution problems associated with traditional coal washing processes and improves their environmental performance. The use of a composition of petroleum sulfide and Fe-Mn composite oxides as the auxiliary absorbent allows for several advantages. First, the sulfur in petroleum sulfide converts trivalent arsenic in coal into pentavalent arsenic, facilitating absorption by the absorbent. Second, the Fe and Mn in the Fe-Mn composite oxides react with sulfur to form iron sulfide and manganese sulfide, preventing sulfur from entering the washing water and causing environmental pollution.