Briefly introduce the production process of antimony trioxide

The production methods of antimony trioxide can be divided into dry method and silver method. Dry method, also known as fire method, is a type of production method that is currently widely used. The dry production of antimony trioxide mainly includes two processes: the antimony smoke method (also known as the indirect method) and the concentrate double kiln smoke method (also known as the direct method). The antimony trioxide prepared by the dry method is mainly cubic, but also contains a certain amount of orthorhombic crystals. ①Metal antimony fuming method The metal antimony fuming method (ie crucible fuming method) used in our country uses pure metal antimony that has been refined to remove harmful impurities as raw materials. When the furnace is opened, the metal antimony is heated and melted in the furnace. After melting, when the temperature reaches the requirement, stop heating, and blow air into the antimony liquid at high temperature to oxidize and volatilize pure antimony trioxide vapor, which can be rapidly cooled to produce fine antimony trioxide powder. While blowing in the air, the metal antimony is continuously added and the air is continuously blown to achieve continuous production. This process is characterized by self-heating smelting, that is, after air is blown, the heat generated by the oxidation of metal antimony can maintain the heat required for the production process. Since the selected raw material is metal antimony after refining and removing impurities, the quality of the antimony trioxide obtained by this method is excellent, and the chemical composition can meet the requirements of national standard 0 level. The chemical reaction of this process is: first calcining antimony sulfide ore at about 1000°C in the presence of coke to produce crude antimony trioxide (containing about 80% of Sb), and then use soda ash as a fluxing agent, and use coke to remove the crude antimony trioxide. Antimony is reduced to metallic antimony, and finally antimony is oxidized to antimony trioxide in the air. ②Double kiln smoked concentrate method The double kiln smoked concentrate method uses antimony concentrate as raw material, and installs the antimony concentrate in the first rotary kiln. After high-temperature oxidation and volatilization, it becomes coarse antimony trioxide powder, and then installs it. Into the second rotary kiln, use high flow to volatilize and oxidize to form steam, which is collected by rapid cooling to form pure antimony trioxide powder. The method has a mature production process and does not require metal antimony as a raw material. The main disadvantage is that there is no refining and removal of impurities in the process, so the chemical purity of the product is slightly worse than that of the antimony smoke method. ③Wet production process The wet production of antimony trioxide can not only process single antimony-containing raw materials, but also process complex mines with multiple metals, such as antimony gold ore, antimony lead ore, antimony mercury ore, sulfide monoxide mixed ore and Copper and lead refining process anode slime, smelter containing antimony smoke and so on.