Tin ore contains a variety of associated components and can be developed as a polymetallic symbiotic ore. Because these valuable components are often densely bound, traditional gravity separation methods struggle to work adequately. It is necessary to vigorously adopt multiple methods of joint beneficiation and develop new joint beneficiation and treatment processes.
The most common sulfides in tin ores are pyrite, pyrrhotite, and arsenopyrite, as well as chalcopyrite, galena, sphalerite, pyrite, and pyrite. Sulfide is much more floatable than cassiterite. Particle flotation and froth flotation are generally used to separate sulfide and cassiterite. During flotation, copper sulfate is used as activator, xanthate is used as collector, and pine alcohol oil is used as foaming agent.
Wolframite is a weakly magnetic mineral, while cassiterite is generally non-magnetic and can be separated in a strong magnetic field. The magnetic field strength for magnetic separation of wolframite is 0.5~0.81. Cassiterite and scheelite have similar densities and permeabilities but different electrical conductivities and floatability. Cassiterite has good electrical conductivity and can become a conductive product in an electrostatic field. Using this property, it can be separated from the non-conductive scheelite.
When the attached water content of the electrostatic separation feed is less than 1%, it can be heated to 105-150°C first to improve the mineral processing effect. Scheelite has good floatability and can be separated from unfloated cassiterite as floating matter under normal flotation conditions. During flotation, add sodium carbonate or ordinary sodium to adjust the PH value of the slurry to 9 to 10, suppress cassiterite, cobalt, and calcite with water glass, and use oleic acid or oxidized paraffin soap as a collector.
There are two flotation methods for cassiterite and zirconium oxide minerals: sulfide the lead oxide minerals with a sulfiding agent, and then add a xanthate collector to flotate the lead: Tin concentrates with low lead oxide content (Pb3%~5%) can be directly reduced Smelting: Tin concentrates with high lead content can also be directly reduced to smelting as long as the tin and lead content are higher than 50%, and refined tin and solder products can be obtained through rough selection and refining.
There are differences in density, specific magnetic susceptibility and floatability between cassiterite and various tantalum-niobium minerals, but the differences are not significant. Therefore, a combined beneficiation process is usually required. For example, low-density gangue minerals are separated by gravity separation, ilmenite, magnetite, and limonite are separated by magnetic separation, and non-conductive zircon, monazite, and phosphate rock are separated by electrostatic separation. Pickling method to remove hydrogen, etc. iron oxide.
The specific magnetic susceptibility and density of cassiterite and ilmenite are quite different, and magnetic separation and gravity separation are mainly used for separation. First use weak magnetic separation to separate magnetite, then use strong magnetic separation to separate ilmenite into magnetic products, cassiterite into non-magnetic products, and finally obtain cassiterite concentrate through gravity separation or electrostatic separation according to the properties of other minerals .
For the separation of coarse-grained cassiterite and zircon, electrostatic separation is effective, with cassiterite entering the conductive product and zircon becoming the non-conductive product. In order to improve the electrification effect, the ore is heated to 80~120°C during electrification. For fine-grained zircon, flotation can be used to separate it, using oleic acid and kerosene as collectors, using sodium carbonate to make the slurry alkaline, using starch to inhibit cassiterite, and flotating zircon.
© 2021 Yantai KZ Mining Processing Technology & Equipment Inc.