14 results about "Selenous acid" patented technology

The application discloses a treatment method for efficiently removing selenium from waste acid, and specifically comprises the following steps: preheating waste acid to be treated for removing selenium, adding sulfuric acid to adjust the H + concentration of 4-6 mol / L, then adding a reducing agent sodium sulfite Na2SO3, and fully stirring and mixing; controlling the temperature to be 55-70 DEG C to perform a first-stage reaction, then adding a composite catalyst prepared by mixing sodium thiosulfate Na2S2O3 and iodine I2, stirring and mixing, continuing to perform a deep reaction, and performing solid-liquid separation after filtration when the reaction is completed. The application uses sodium sulfite reduction, iodine and sodium thiosulfate catalysis as a substitute for the traditional SO2 reduction mode, solves the problem that the traditional SO2 reduction method is limited by pH liquid, accelerates the reaction rate through iodine and sodium thiosulfate catalysis, simultaneously solves the problem that the traditional sulfite cannot reduce selenium-containing substances other than selenite, and improves the reduction effect of selenium.

The invention discloses a preparation method of soluble selenium glycinate, which comprises the following steps: S1, reacting a selenium source with strong basic hydroxide in water to generate selenite; s2, reacting selenite with glycine and hydrogen peroxide in water for 12-16 hours to generate selenium glycinate; the reaction temperature is 5-15 DEG C, and the reaction needs to be carried out under a dark condition. The selenium glycinate product obtained by adopting the preparation method is stable in content and good in water solubility, the preparation process is simple, the cost is low, the operation is simple and convenient, additional chemical additives are not needed, and the operation steps are reduced; a by-product selenide salt in a chemical reaction can react with hydrogen peroxide to regenerate selenite, and the whole reaction process does not have redundant waste, so that the production concept of green chemistry is met; the product is good in solubility, wider in application field and better in application effect.

This invention discloses a selenite crystal and its preparation method. X-ray powder diffraction of the selenite crystal, measured using Cu-Kα radiation, yielded diffraction angles (expressed as 2θ) of 17.7°±0.2°, 19.5°±0.2°, 20.0°±0.2°, 22.9°±0.2°, 24.5°±0.2°, 24.9°±0.2°, 26.2°±0.2°, 29.8°±0.2°, 30.2°±0.2°, 31.4°±0.2°, and 33°. Characteristic peaks are observed at 0°±0.2°, 34.3°±0.2°, 35.8°±0.2°, 36.6°±0.2°, 37.4°±0.2°, 37.5°±0.2°, and 38.4°±0.2°. A characteristic endothermic peak is observed at 73.4℃ in the differential scanning calorimetry (DSC) spectrum of the crystal. This invention features a simple preparation route, mild reaction conditions, convenient operation, low cost, and good process reproducibility. The prepared selenite has a stable crystal form, making it suitable for large-scale industrial production of pharmaceutical raw materials.

The invention discloses a method for recovering Se and TeO2 from tellurium-containing crude selenium refining slag, which comprises the following steps of: crushing the tellurium-containing crude selenium refining slag, performing temperature-controlled roasting, decomposing nitrate, and oxidizing tellurium into a high valence state; the roasting slag and a reducing agent are mixed and heated under the vacuum condition, so that the selenium compound is reduced into elemental Se and volatilized, and meanwhile high-valence tellurium is reduced into tetravalent tellurium salt residues; crushing the reduced product, performing water-soluble leaching, and filtering to obtain a solution containing selenite and tellurite and TeO2 precipitate; adding acid into the leaching filtrate to hydrolyze the tellurite salt into TeO2 precipitate, and filtering and separating to obtain TeO2 and selenium-containing filtrate; finally, acid and a reducing agent are added into the selenium-containing filtrate, and selenite is reduced into elemental Se precipitate. The method realizes efficient separation and recovery of selenium and tellurium, is reasonable in process flow and high in recovery rate, and has a good application prospect.

The application provides a method for preparing 6N selenium from 2N selenium, and belongs to the field of high-purity metal preparation.The method comprises the following steps: oxidizing and roasting 2N selenium to obtain selenium dioxide vapor; mixing the selenium dioxide vapor with water to perform a combination reaction to obtain a selenite solution; mixing the selenite solution with a reducing agent to perform a reduction reaction to obtain 3N and / or 4N selenium; melting the 3N and / or 4N selenium, and then immersing a crystallizer into the obtained melt to perform rotary crystallization to obtain 6N selenium.The application roasts selenium with oxygen to generate selenium dioxide to remove high-boiling impurities; the selenium is enriched by using the property that selenium dioxide is easily soluble in water, the impurities (such as selenium dioxide) that are difficult to dissolve in water are removed to realize the purification of selenium; the 3N and / or 4N selenium is further purified by rotary crystallization to realize the further purification of selenium.

The application provides a genipin cross-linked selenium nanoparticle and a preparation method and application thereof, and belongs to the field of functional nanomaterials and intelligent nutrition delivery technology. The preparation method comprises the following steps: dissolving a protein substance in water to obtain a protein solution, adding a selenous acid compound, then adding vitamin C and genipin, performing cross-linking reaction, and performing dialysis on the obtained reaction solution to obtain the genipin cross-linked selenium nanoparticle. The application innovatively uses the concentration of genipin as a control switch, realizes active and accurate control of the release rate of selenium in the intestinal tract, realizes the treatment effect on colitis through instantaneous high-concentration release under a low-concentration selenium administration dose, and effectively solves the defect that the "nutrition-toxicity" dose range of selenium is narrow.

The present invention relates to methods for biological wastewater treatment for Se control in Se-laden wastewater. The Se contaminants in the wastewater include the Se oxyanions selenate (SeO42−) and selenite (HSeO3−), which are biochemically reduced and transformed to elemental selenium (Se0) by microorganisms through anaerobic biological reduction. The resulting Se0 is entrained in the biomass, which is further processed to enable the efficient recovery of concentrated Se0.

This disclosure proposes a lithium selenite / selenium dioxide bilayer-coated ternary material, wherein the chemical formula of the lithium selenite / selenium dioxide bilayer-coated ternary material is LiNi. a Co b Mn c O2·xLi2SeO3·ySeO2, where Li2SeO3 is the inner coating layer and SeO2 is the outer coating layer; where a+b+c=1, 0.6<a<1, 0<b+c<0.4, 0<x<0.3, 0<y<0.1, 0<x+y<0.4.

The application discloses a selenium catalytic synthesis method of polylactic acid in the technical field of material chemistry. L The amount of the substituted selenous acid as the catalyst precursor added into the lactic acid is 0.02-0.08% of the mass of the lactic acid. L The amount of the substituted selenous acid as the catalyst precursor added into the lactic acid is 0.02-0.08% of the mass of the lactic acid. L The amount of the substituted selenous acid as the catalyst precursor added into the lactic acid is 0.02-0.08% of the mass of the lactic acid. 3 The polylactic acid can be obtained by blowing the material into a flow of 0.4-1.0 cm / s air and heating at 160-180 DEG C. The method is simple, and the use of metal catalysts can be avoided, so that metal residues in the product are eliminated, and medical-grade polylactic acid material can be directly prepared.

The invention relates to the technical field of preparation of high-purity inorganic compounds, and discloses a rectification purification method for removing trace metal impurities in selenium dioxide, which comprises the following steps: dissolving crude selenium dioxide in an aqueous solvent to form a seleninic acid aqueous solution, adding a chemical reducing agent to regulate the valence state of the impurities, and adding a ferric nitrate auxiliary agent and a hydrolyzable alkaline precursor substance; heating to hydrolyze the precursor substance so as to generate alkali in situ, and realizing homogeneous co-precipitation of iron cations and impurities; the method comprises the following steps: separating precipitates, carrying out thermal dehydration on a purified seleninic acid aqueous solution obtained after separation, and carrying out thermal decomposition removal on residual nitrate anions by heating while crystallizing and separating out selenium dioxide. By selecting ferric nitrate and reusing the heating function of the thermal dehydration step, the problem of secondary pollution of anions caused by conventional ferric salt auxiliaries is avoided.

The invention relates to a method for preparing sodium selenite from crude selenium recovered from copper anode slime. The method comprises the following steps: S1, oxidizing: oxidizing the crude selenium recovered from the copper anode slime under the conditions that the temperature is 500-550 DEG C and the oxygen flow is 0.9-1.0 L / min; after the selenium is completely burnt, stopping heating, continuing to introduce O2, and then cooling to room temperature in air to obtain an oxidation product SeO2; s2, separation and purification: fully dissolving the oxidation product SeO2 with deionized water, filtering, heating, evaporating and crystallizing, condensing, re-dissolving, boiling and cooling to obtain a seleninic acid solution; s3, neutralization and crystallization: adding a NaOH solution into the seleninic acid solution for reaction, and performing vacuum drying, standing, cooling and crystallization to obtain crystalline sodium selenite; and S4, heating and dehydrating: heating and dehydrating the crystallized sodium selenite to obtain an anhydrous sodium selenite product. The process is simple in production process, stable and reliable in quality, low in cost and high in economic benefit.

The invention discloses a production device and a production method of selenium gluconate. The production device comprises a base, a reaction kettle is horizontally arranged above the base, a motor is arranged on one side of the reaction kettle, and a belt transmission device is arranged between the motor and the reaction kettle; a Venturi reaction tube is vertically arranged above the reaction kettle close to one end of the belt transmission device; the Venturi reaction tube is sequentially divided into a primary mixing section, a secondary mixing section and a diffusion section from top to bottom; a third liquid inlet is formed in the side wall of the outer circumference of the secondary mixing section, and one end of the third liquid inlet is hermetically connected with a control valve; a hydraulic control device is arranged on one side of the base, and a hydraulic pipe is arranged between the hydraulic control device and the control valve; according to the invention, seleninic acid and gluconic acid are added into a reaction kettle, and a continuous flow reaction technology is adopted, so that the traditional intermittent kettle reaction is successfully converted into continuous production; the invention also adopts a partition temperature control type reaction kettle to realize the gradient accurate control of the reaction temperature.

This invention provides a method for preparing a selenite-sulfide nanocomposite material. Nickel selenite is grown in situ on nickel-plated carbon cloth using a hydrothermal method, followed by electrodeposition of transition metal sulfides onto its surface. Selenite, as a reinforcing phase in the positive electrode material of a supercapacitor, improves the conductivity of the composite material and releases selenate ions, which, along with sulfate ions released from the sulfides, adsorb onto the material surface, promoting redox kinetics in the electrochemical process. The prepared selenite-sulfide composite nanoelectrode material exhibits excellent supercapacitor performance at a current density of 1 A g. ‑1 At that time, its specific capacity was 3509 F g. ‑1 An asymmetric supercapacitor composed of commercially available activated carbon at 844 W / kg ‑1 The power density reached 141Wh / kg. ‑1 High energy density. This supercapacitor exhibits good cycle stability at 5A g. ‑1 Under these conditions, after 25,000 cycles, the capacity retention rate was 100.2%.

The invention provides genipin cross-linked selenium nano-particles and a preparation method and application thereof, and belongs to the technical field of functional nano-materials and intelligent nutrition delivery, the preparation method comprises the following steps: dissolving a protein substance in water, hydrating to obtain a protein solution, adding a seleninic acid compound, then adding vitamin C and genipin, and uniformly stirring to obtain the genipin cross-linked selenium nano-particles. And carrying out a cross-linking reaction, and dialyzing the obtained reaction liquid to obtain the genipin cross-linked selenium nanoparticles. The genipin concentration is innovatively used as a regulation switch, active and accurate control over the release rate of selenium in the intestinal tract is achieved, namely, the treatment effect on colitis can be achieved through instant high-concentration release under the condition of the low-concentration selenium administration dosage, and the defect that the nutrition-toxicity dosage range of selenium is narrow is effectively overcome.