100results about "Arsenites/arsenates" patented technology

The present invention provides a method of forming inorganic pigments using one or more metal alloys. Metal alloys used in the method of the invention are preferably milled to a mean particle size of less than about 10 microns, may be mixed with other metal oxides, and calcined in the presence of oxygen in a rotary kiln. Inorganic pigments formed in accordance with the method of the invention can be used in a wide variety of applications, including the coloration of glass matrixes, ceramic bodies, polymers, and paints.

The present invention relates to a method for preparing an electroactive metal polyanion or a mixed metal polyanion comprising forming a slurry comprising a polymeric material, a solvent, a polyanion source or alkali metal polyanion source and at least one metal ion source; heating said slurry at a temperature and for a time sufficient to remove the solvent and form an essentially dried mixture; and heating said mixture at a temperature and for a time sufficient to produce an electroactive metal polyanion or electroactive mixed metal polyanion. In an alternative embodiment the present invention relates to a method for preparing a metal polyanion or a mixed metal polyanion which comprises mixing a polymeric material with a polyanion source or alternatively an alkali metal polyanion source and a source of at least one metal ion to produce a fine mixture and heating the mixture to a temperature higher than the melting point of the polymeric material, milling the resulting material and then heating the milled material. It is another object of the invention to provide electrochemically active materials produced by said methods. The electrochemically active materials so produced are useful in making electrodes and batteries.

The invention provides a method for synthesizing ferricarsenate from arsenic-containing smoke dust by leaching, pressure oxidation and conversion, and consolidating the ferricarsenate. The method comprises the following steps of: leaching the arsenic-containing smoke dust by using 10 to 30g/L of dilute sulfuric acid solution; mixing and stirring the smoke dust and powdered pyrite; adding the mixture into a closed stirring reactor; introducing oxygen into the reactor until the oxygen partial pressure is between 0.6 and 1.5MPa; heating the reactor to the temperature of between 100 and 160 DEG C, stirring the mixture to perform reaction for 2 to 4 hours; filtering the reaction product to obtain mixed solid of ferricarsenate and sulphur, and 10 to 30g/L of dilute sulfuric acid solution which is returned and leached; and solidifying the mixed solid to obtain environment-friendly hydrophobic solid with high strength. The method has no emission of waste gas or waste water in the treatment process, can solve the opening problem of arsenic in various arsenic-containing smoke dusts, and eliminates pollution of the arsenic-containing smoke dust to the environment.

A method is provided for the efficient stabilization, removal and disposal of arsenic-containing wastes generated in metal recovery processes that employ roasting techniques and the like. The conversion of the mostly trivalent arsenite compounds in the wastes to mostly pentavalent solid arsenate precipitates is accomplished by mixing the wastes with water and a ground iron-containing mineral, such as goethite, to form an aqueous slurry of wastes and ground iron-containing mineral, acidifying the slurry to a pH of less than about 1.0, treating the acidified slurry with oxygen gas in a pressurized vessel at a temperature higher than about 120° C. and providing an oxidation catalyst comprised of a water-soluble nitrate and a water-soluble iodide. The overall efficiency of the controlling chemical reactions is improved by the addition and use of the catalyst. The resulting solid arsenate precipitates, in the form of scorodite, are ideally suited for safe disposal with minimum or no further treatment. Unconverted soluble trivalent arsenic compounds remaining in solution may be converted and precipitated as additional scorodite by mixing and agitating the slurry with soluble iron salts under controlled conditions. The resulting precipitates meet or exceed environmental requirements for impoundment and safe disposal.

The invention discloses a method for removing arsenic hydride in tail gas of an iron making blast furnace by a wet process. In the method, the tail gas of the iron making blast furnace is subjected to water washing and alkali washing to remove dust and acidic gas, then the tail gas is introduced into a reaction tower containing sodium hypochlorite, the arsenic hydride in the tail gas is removed by the strong oxidation action of sodium hypochlorite, and the thus, the tail gas is purified. With simple process and low treatment cost, the method is not limited by field, can treat complexly composed tail gas containing arsenic hydride and is suitable for industrial application.

The invention relates to a method for synthesizing water insoluble calcium arsenate by oxidizing arsenic in arsenic-containing smoke dust or solution and belongs to the technical field of metallurgy. The method comprises the following steps of: (1) mixing and stirring the arsenic-containing smoke dust or solution with weighed lime to make slurry; and (2) adding the slurry material into a closed stirring reactor, introducing the air or oxygen into the closed container till the oxygen partial pressure in the closed container reach 0.6 to 1.5MPa, stirring the slurry material under a closed condition to perform an reaction to oxide trivalent arsenic in the slurry material into pentavalent arsenic and convert the pentavalent arsenic into water insoluble calcium arsenate, cooling the reaction solution, and filtering the reaction solution to obtain solid calcium arsenate. In the method, the arsenic in the arsenic-containing smoke dust or solution is oxidized into the pentavalent arsenic and the pentavalent arsenic is converted into the water insoluble calcium arsenate, neither waste gases nor waste water is produced in the process, the problem of opening a way for the arsenic in various kinds of arsenic-containing smoke dust is solved, and the environmental pollution caused by arsenic is eliminated.

The present invention provides a method for manufacturing scorodite in which scorodite may be obtained at high production efficiency and a high As concentration ratio. The present invention provides a method for manufacturing crystalline scorodite from acidic aqueous solution containing pentavalent As and trivalent Fe, the method comprising a step for adding a basic sodium compound to the acidic aqueous solution such that the sodium concentration in the acidic aqueous solution becomes larger than 0 g/L and equal to or less than 4 g/L.

The present invention is to provide a process for producing a scorodite that can shorten the time required for synthesizing the scorodite, and further can improve the yield of arsenic and iron into the scorodite. Accordingly, a process for producing a crystalline scorodite from an acidic aqueous solution containing pentavalent As and trivalent Fe, wherein the synthesis of the crystalline scorodite is performed after the molar ratio of trivalent Fe to pentavalent As contained in the acidic aqueous solution is adjusted to be equal to or more than 0.9 and equal to or less than 1.1 is provided.

The invention provides a method and application for removing arsenic from black copper sludge, and relates to the technical field of arsenic removal. The method for removing the arsenic from the blackcopper sludge comprises the steps that the black copper sludge and alkali are mixed and roasted; and after a roasted product and water are mixed, infiltrated and filtered, arsenic removal liquid is subjected to fractional crystallization to obtain a sodium arsenate product and alkali. The method is easy and convenient to operate and high in controllability, alkali can be cyclically utilized, resource regeneration is achieved, and environment protection and high efficiency are achieved.

The invention relates to a method for producing magnesium arsenate by using arsenic-containing waste liquid. The arsenic-containing waste liquid produced in the acid-making process of non-ferrous metal smelting enterprises by adopting a 'pyrogenic-process smelting-smoke acid-making system' process is used as a raw material to produce the magnesium arsenate. Firstly, iron, zinc and copper are removed in sequence, then As<3+> in the liquid is oxidized into As<5+> and Mg<2+>, full compounding is performed to produce a Mg3(AsO4)2 crude product, and finally the Mg3(AsO4)2 crude product is purified to produce a magnesium arsenate product. The arsenic-containing waste liquid is treated while high-purity magnesium arsenate is produced, and the effects of saving energy, reducing emissions and recycling resources are achieved.

The invention provides a method of treating high-concentration arsenic and cadmium in acidic waste water with granular titanium dioxide. The method includes following steps: regulating the pH of the waste water to 7 with lime milk and industrial-grade NaOH, passing the waste water through three in-series filter columns filled with the granular titanium dioxide continuously; and performing three-time continuous adsorption, so that the concentration of arsenic and cadmium in discharged water can both reach national sewage emission standard. The method can effectively remove high-concentration trivalent arsenic and heavy metal ion cadmium in the waste water, wherein the adsorbent can be recycled and reused. Meanwhile, the method also can recycle arsenic. The whole process is almost free of generation of waste residue so that the method is environment-friendly and can generate economic benefit.

An anode in a Direct Carbon Fuel Cell (DCFC) operating in a temperature range between 500 and 1200 degrees Celsius is provided. The anode material has high catalytic activity and selectivity for carbon oxidation, sufficient oxygen non-stoichiometry, rapid oxygen chemical diffusion, wide thermodynamic stability window to withstand reducing environment, sufficient electronic conductivity and tolerance to sulfur and CO₂ environments. The anode has doped ruthenate compositions A_1−xA′_xRuO₃, AB_1−yRu_yO₃, or A_1−xA′_xB_1−yRu_yO₃. A and A′ may be divalent, trivalent, or tetravalent cation, and B is a multivalent cation. A is among lanthanide series elements La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er or Yb, and dopant A′ is from Group IIA, IIIB, or IVB elements. The doped ruthenates can also be a (AB_1−yRu_yO₃) structure or an ordered Ruddlesden-Popper series ((A_1−xA_x′)_n+1(B_1−yRu_y)_nO_3n+1) structure where n=1 or 2. The dopant B is among Group IVB, VB, VIB, VIII, IB, and IIB elements.

The invention discloses a pyrogenic copper smelting white smoke resource comprehensive utilization method. The method comprises the following specific steps: white smoke and caustic soda are mixed in proportion; sodium sulfate is added, so that solution has a certain SO42- concentration; air is fed at 80-95 DEG C for oxidation leaching; then, the filtration is performed; and a proper amount of water is used for washing filter cakes. Filtrate has the main component of sodium arsenate, and is evaporated, condensed, cooled, crystallized, filtered and separated to obtain a sodium arsenate double salt product; and mother liquor after separation of sodium arsenate is returned to the white smoke for alkali leaching. The filter cakes in alkali leaching are pulped; sulfuric acid is added for acid leaching at 80-95 DEG C; then, the filtration is performed; the filter cakes have the main component of lead sulfate; and lead sulfate serves as a lead concentrate for lead smelting. Filtrate is copper sulfate solution; iron powder is added for replacement to obtain sponge copper; and the sponge copper is returned to a pyrogenic copper smelting system for refining as electrolyzed copper. The leaching rate of arsenic in the white smoke can reach above 95%; such precious metals as copper, lead, gold and silver are nearly not leached; the leaching rate of copper is higher than 98%; the content of lead in acid leaching slag is higher than 50%; and such precious metals as gold and silver are further enriched.

A method for preparing the cupric arsenite is provided. Water is firstly added in the reactor, and sodium hydroxide or potassium hydroxide lye is added in accordance with the 0.5mol/L to 5mol/L quantity volume concentration of matters and is stirred to dissolve. The arsenic trioxide is added in accordance with the mol ratio of 3 : 2 to 3 : 1 between the hydroxyl and the arsenic of the arsenic-alkali and the pH value of the solution is adjusted to 6.0 to 10.. Under 0 DEG C. to 40 DEG C., the copper sulfate solid is added in accordance with the mol ratio of 1 : 1 to 2 : 1 between the copper and the arsenic. The caustic lye is added and the pH value of the solution is adjusted to 6.0 to 10. reversely. The cupric arsenite is gained after filtering and washing and is repeatedly washed by clear water and is added in the copper electrolyte or the decoppering final solution; the sedimentation containing As, Sb and Bi produced after reaction is filtered and removed and the removal rate of the Sb and Bi impurities in the copper electrolyte highly reaches 50 per cent to 70 per cent. The cupric arsenite added in the copper electrolyte is characterized by strong purification capacity, simple process and low cost.

The present invention includes an electrochemical redox active material. The electrochemical redox active material includes a cocrystalline metallic compound having a general formula A_xMO_4-yXO_y.M′O, where A is at least one metallic element selected from a group consisting of alkali metals, M and M′ may be identical or different and independently of one another at least one selected from a group consisting of transition metals and semimetals, X is P or As, 0.9≦x≦1.1, and 0<y<4.

The invention belongs to the technical field of industrial sewage treatment, and particularly discloses a method for resource utilization of waste sulfuric acid wastewater produced in copper smeltingand acquisition of arsenic-containing products. The method comprises the following steps: 1, oxidization of trivalent arsenic: oxidizing the waste sulfuric acid wastewater by air and hydrogen peroxidein sequence; 2, separation of arsenic from fluorine and chlorine: carrying out negative pressure evaporation after oxidation to obtain a condensate A containing fluorine and chlorine, a concentratedsolution B and arsenic pentoxide crystals; 3, separation of fluorine and chlorine: absorbing the condensate A with magnesium oxide to obtain a magnesium fluoride product and diluted hydrochloric acid;4, recovery of valuable metal: adding a sodium sulfide solution into the concentrated solution B to obtain a valuable metal precipitate and arsenic-containing waste liquid C, and returning the valuable metal precipitate to a furnace for refining; and 5, crystallization: adding caustic soda flakes or recycled concentrated alkali liquor E into the arsenic-containing waste liquor C, adjusting a pH value to 13.5-14.0 to obtain a sodium arsenate product and a crystallized filtrate D, filtering the crystallized filtrate D, and conducting concentrating to obtain a sodium sulfate product and the concentrated alkali liquor E. According to the method, waste sulfuric acid wastewater is subjected to resource recycling, and arsenic pentoxide and sodium arsenate products are obtained.