| Andalusite is an anhydrous aluminum-silicate mineral. Although it has the same chemical composition with kyanite and sillimanite,however,andalusite has totally different structures from those and thus it has different physical properties. South Africa is the biggest andalusite producer and exporter in the world, while the reserves of China and France are top of the world. The paper is about the separation technology of FengCheng andalusite.It is known that, by process mineralogy, the major mineral of FengCheng are andalusite, quartz and biotite,a little feldspar,garnet, muscovite, and some microscale iron minerals.The research include the flotation characteristics of andalusite pure mineral and gangue pure minerals in sodium dodecyl sulfate(SDS) system and sodium alkylsulf-onate system, the separation condition of andalusite, quartz and biotite. The influence between andalusite and gangue minerals is also researched.The separation folw sheet is grind-desliming-decarburization-flotation-magnetic. The test demonstrate that the fineness of grind is-0.074mm80%, the partical size of desliming is20μm, the dosage of kerosene is60g/t and2#oil60g/t in the decarburization.The separation result of the SDS system show that the Al2O3grad of the andalusite concentration reach50.34%, the rate of concentration production is5.76%, while the flow sheet include rougher with dosage of fixed collector130g/t and three-step cleaner, with65g/t collector in every step, and the pH value is11.0.The separation result of the sodium alkylsulfonate system show that the Al2O3grad of the andalusite concentration reach48.5%, the rate of concentration production is12.52%, while the flow sheet include rougher with dosage of collector2200g/t and four-step cleaner, with630g/t collector in the first step, and the pH value befor flotation is3.0. It can effectively remove the weak magnetic mineral inclued biotite and garnet from the flotation concentration by magnetic separation, as resule the grad of concentrate will be increased more. It is know that960KA/m is the best magnetic field intensity.It is studied in this paper that the crystal chemistry and the solution chemistry of the main minerals, like andalusite, quartz and biotite. Through the mechanism analysis, the mechanism of hydrophilicity on the minerals surface can be found out, the flotation behavior of andalusite in SDS system and sodium alkylsulf-onate system can be explained.All of this is important for the separation of FengCheng andalusite. |
