6 results about "Selenium product" patented technology

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 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 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.