- Copper powder oxidation method uses copper ash and copper slag as raw materials to be calcined, and is initially oxidized by gas heating to remove moisture and organic impurities in the raw materials. The resulting primary oxide is naturally cooled, pulverized, and subjected to secondary oxidation to obtain a crude copper oxide. The crude copper oxide is added to a reactor pre-packed with 1:1 sulfuric acid, and reacted under heating and stirring until the relative density of the liquid is 1 times. When the pH is 2 to 3, the reaction end point is formed, and a copper sulfate solution is formed and allowed to stand. After clarification, iron shavings are added under heating and stirring to displace copper, and then washed with hot water to no sulfate and iron. The mixture was centrifuged, dried, and oxidized and calcined at 450 ° C for 8 hours. After cooling, it was pulverized to 100 mesh, and then oxidized in an oxidizing furnace to obtain a copper oxide powder.
2. Thermal decomposition of copper nitrate. The electrolytic copper was dissolved in dilute nitric acid and then evaporated to dryness on a water bath, and then heated very slowly from 90 ° C to 120 ° C in a desiccator. When a soft basic salt is formed, it is boiled in water, filtered, and dried; then it is slowly heated to 400 ° C to remove most of the nitric acid; then pulverized and heated to 850 ° C for 1 h to decompose it into oxidation. copper. In order to make the reaction more complete, the product can be pulverized again, heated at about 700 ° C for 1 h, and then placed in a desiccator for cooling.
3. Copper carbonate thermal decomposition method. The copper powder or copper wire is completely dissolved in a fume hood with as little as 6 mol/L of nitric acid. If the solution is opaque, it needs to be filtered. Further, sodium carbonate is mixed into a solution and mixed with the above copper nitrate solution, and boiled to form a black basic salt precipitate. After the solid settles, the supernatant is discarded, washed thoroughly by decantation, filtered, and dried. It was placed on an evaporating dish and heated with a small heat to dissolve it into copper oxide.
4. Dissolve copper wire or copper powder in 6moL/L nitric acid to keep a slight excess of copper, heat to a solution pH of 3-4 to remove iron hydroxide precipitate, then mix with 10% (mass) sodium carbonate solution, heat Boiling, alkaline salt is precipitated, the supernatant is discarded, washed thoroughly with water, filtered, and dried. The dried basic copper carbonate is decomposed into black copper oxide powder by heating under low temperature with sufficient agitation:
When there is no more carbon dioxide generated, it indicates complete decomposition.
5. The high-purity copper nitrate was dissolved in electrically conductive water, filtered, and excess high-purity NH4OH was added to the supernatant to remove impurities, and the filtrate was neutralized with high-purity nitric acid to precipitate copper hydroxide. Filtration, washing once with conductive water, adding nitric acid to dissolve the precipitate, adding high-purity ammonium carbonate to precipitate copper carbonate, washing, drying, drying in an oven at 200 ° C, burning at 450 ~ 550 ° C for 3 ~ 4h, Spectral Pure Copper Oxide:
