11 results about "Selenium product" patented technology

The invention relates to the technical field of microbiology, in particular to a marine yeast strain and application thereof in preparation of nano-selenium, and provides a method for efficiently synthesizing nano-selenium in a culture medium containing sodium selenite by using the strain. The biological nano-selenium has an amorphous structure, the particle size distribution of the biological nano-selenium is 100-500 nm, the Zeta potential of the biological nano-selenium reaches-26.1 mV, and the surface of the biological nano-selenium is coated with biological molecules. According to the method, sodium selenite reduction rate as high as 95.4% and nano-selenium yield as high as 18.5 mg / g can be achieved, meanwhile, the prepared nano-selenium shows excellent antioxidant activity in vitro and on the cellular level, the cytotoxicity of the nano-selenium is remarkably lower than that of inorganic selenium, oxidative stress induced by hydrogen peroxide can be effectively relieved, and the nano-selenium can be used for preparing a nano-selenium product. Therefore, a safe, efficient and stable novel nano-selenium feed additive and antioxidant source is provided for aquaculture.

The invention discloses a refined selenium production process, and belongs to the technical field of metallurgy. The method is characterized in that coarse selenium powder is subjected to regulation and control oxidation, melting separation, alkaline leaching and acidification reduction to obtain a high-yield fine selenium product. According to the method disclosed by the invention, the substance obtained by regulating and oxidizing the crude selenium by utilizing the melting point difference of the substance is utilized, the substance containing the selenium element is melted into the melt to be enriched by controlling the temperature, the effective separation of tellurium and selenium is realized, the substance containing the selenium element is leached by utilizing the alkaline solution of sodium sulfite and sodium hydroxide and is converted into the selenium-containing leaching solution, and the tellurium and the selenium are enriched. The pH value of the solution is adjusted to 5-6 through sulfuric acid, selenium is precipitated out, a refined selenium product with the purity reaching 99.99% is obtained, and the recovery rate of selenium exceeds 92%. The method is reasonable in design, few impurities are introduced in the process, the high recovery rate is achieved while the selenium grade exceeds 99.9%, and the selenium resource utilization rate is remarkably increased.

The application provides a method for efficiently removing impurity tellurium in crude selenium, and relates to the field of dispersed metal purification technology.The method comprises the following steps: adding SeO2 into crude selenium raw material which is soluble with tellurium, and melting, so as to selectively oxidize elemental tellurium in the crude selenium melt; and then, by virtue of the difference between the saturated vapor pressures of oxidized tellurium and selenium, the impurity tellurium in the crude selenium can be efficiently removed through vacuum distillation treatment, the tellurium is enriched in the form of oxidized tellurium in the distillation residue, and selenium products with a certain purity are obtained in the volatile matter. By using the method, the recovery rate of selenium can reach more than 90%, the added SeO2 in the crude selenium is reduced to elemental selenium by tellurium, the residual SeO2 in the reaction is volatilized in the melting process, and no other impurities are introduced, so that an innovative method for the purification of selenium is provided. The method is simple, efficient, energy-saving and environment-friendly, and low in cost, and has a milestone significance in the field of selenium-tellurium separation.

The invention discloses a method for selectively preparing refined selenium from copper anode slime, CuCl2 with the pH value of 1-3 is adopted as a conversion agent of a complex selenium-containing phase in the copper anode slime, conversion from CuAgSe and Ag2Se to CuSeO3, Cu (OH) 2 and AgCl is successfully achieved, the follow-up normal-pressure sulfuric acid leaching selenium leaching rate exceeds 98%, and all precious metal is enriched in leaching residues; aiming at the characteristic that the grade of SO2 reduced crude selenium is not high enough, an HCl system is adopted for pressurized oxidation impurity removal, so that the selenium grade is improved, and a leaching solution can return to the oxygen pressure conversion process after being pretreated; the method is ingenious in conception, and has the advantages of being simple in technological process, concentrated in noble metal trend, high in selenium product recovery rate and high in selenium product purity through organic combination of the steps of oxygen pressure conversion, atmospheric pressure leaching, SO2 reduction and oxygen pressure leaching.

The utility model relates to the field of pharmaceutical equipment, concretely relates to a selenium product tablet hardness testing device, including base, the upper end of base is provided with work table, base is provided with frame, the vertical setting of frame has the telescopic mechanism with work table upper and lower correspondence, the lower end of telescopic mechanism is connected with pressure test module, and the controller and display connected with pressure test module are set up on the frame, the lifting frame is set up on the work table, and the lifting frame is provided with the protective cover of lower end opening, the upper end of protective cover is provided with the through -hole with telescopic mechanism correspondence, the negative pressure dust collection unit is set up on the work table, and the negative pressure dust collection unit is provided with the hose connected with protective cover, the utility model has the effect that the debris and dust are convenient to collect.

The application belongs to the technical field of fermentation engineering, and specifically provides a production method of selenium of Kluyveromyces marxianus. A Kluyveromyces marxianus strain with good tolerance to sodium selenite, high selenium conversion rate and good growth is screened through domestication, fermentation production is carried out by using the strain, and fermentation process and post-treatment drying process are optimized, so that the selenium content of the selenium product of the yeast is greatly improved to 5200 mg / kg, and the organic selenium content is greater than or equal to 98.0%. The method has simple process and is easy to mass produce, the strain grows vigorously, the cycle is short, and high-quality industrialized production conversion is realized.

The invention relates to the technical field of biosynthesis and nano material preparation, and discloses an organic biosynthesis nano small molecule selenium stock solution and a preparation method thereof, the preparation method comprises the following steps: S1, screening and gene optimization of efficient selenium transformation strains; s2, fermentation process optimization based on metabolic characteristics; s3, synergistic extraction and biosynthesis of the plant source selenium component; s4, stock solution integrated extraction based on physicochemical characteristics. According to the method, efficient selenium transformation strains are screened, gene optimization is carried out, fermentation process optimization based on metabolic characteristics is matched, the transformation efficiency of inorganic selenium to organic selenium is greatly improved, the yield of nano-selenium is remarkably increased, compared with a traditional method, the production cost is reduced, more high-quality organic selenium products can be produced within shorter time, and the method is suitable for industrial production. And powerful support is provided for large-scale production.

The application discloses a method for refining and purifying crude selenium in a vacuum, and belongs to the field of purification of dispersed metals. The method comprises the following steps: mixing crude selenium raw materials with Pb or Cu to obtain a molten product; and performing vacuum distillation on the molten product to remove volatile matters and obtain refined selenium products with a purity higher than 99%. The method utilizes the difference between saturated vapor pressures to remove metal impurities, and is performed under a vacuum condition, so that the method is green, efficient, low in cost and simple in process.

This invention discloses a method for separating and recovering selenium and fixing arsenic in copper anode mud using vacuum roasting, comprising the following steps: a) crushing and screening the copper anode mud to obtain powder; b) uniformly mixing the obtained powder with an iron-based arsenic fixing agent to obtain mixture A; c) placing mixture A in a roasting furnace, then introducing a mixture of inert carrier gas and oxygen-containing gas, and maintaining the system absolute pressure at 1-20 kPa and oxygen partial pressure at 1%-10%, roasting at 400-750℃ for 0.5-4 hours to obtain roasting residue B with arsenic fixed in the form of ferric arsenate and selenium-containing flue gas C; d) passing the selenium-containing flue gas C into a sodium thiosulfate solution for absorption and reduction, and obtaining elemental selenium product D after filtration, washing, and drying; e) leaching the roasting residue B with dilute sulfuric acid to recover the valuable metals copper and silver therein. The above method has a short process flow, good selenium and arsenic separation effect, and can ensure environmental safety in the subsequent valuable metal recovery process.

This invention provides a method and system for the synergistic recovery of mercury and selenium from acid sludge based on a Fe(III) / Fe(II)-O2 catalytic cycle coupled with selective oxidation. The method includes the following steps: mixing acid sludge, sulfuric acid solution, Fe(III) salt, and chloride to form a redox pair containing Fe(III) and Fe(II) and Cl... ‑ The slurry is leached in the presence of oxygen-containing gas by adding an oxidation initiator and heating to form a catalytic oxidation cycle, thereby obtaining the leaching product. The leaching product is then subjected to solid-liquid separation to obtain leaching residue and a leachate rich in Se(IV) and mercury chloride complex. A reducing agent is added to the leachate to reduce Se(IV) to elemental selenium, and crude selenium product and mercury-containing mother liquor are separated. The mercury-containing mother liquor is then subjected to electrochemical reduction treatment to deposit mercury in the form of elemental metal on the cathode, and the mercury-poor solution is recovered.

The invention discloses a method for efficiently removing arsenic from crude selenium produced by copper anode slime sulfating roasting, and belongs to the technical field of hydrometallurgy. According to the method, acid-alkali two-step wet pretreatment is combined with a vacuum distillation process. The method comprises the following steps: firstly, soaking crude selenium for the first time at a specific liquid-solid ratio by using a dilute sulfuric acid solution with the pH value of 1 to preliminarily remove most arsenic; then, an alkaline solution with the pH value being 9 is used, a composite vulcanizing agent is added, second-time soaking is carried out under the heating condition, impurities such as arsenic and tellurium are deeply removed, and washing is carried out through high-purity water; and finally, carrying out vacuum melting and distillation on the pretreated crude selenium to obtain a high-purity selenium product. The technical problem that arsenic and selenium are difficult to separate due to the fact that the boiling points are close is effectively solved, the technological process is short, operation is easy and convenient, the impurity removal efficiency is high, 3N or 4N high-purity selenium with the arsenic content lower than 0.0005% can be stably produced, and the industrial application value is remarkable.