Production of potassium feldspar concentrate from a low-grade pegmatitic ore in Turkey

摘要

This paper describes the possibility of producing various grade feldspar concentrates by magnetic separation and flotation. A representative sample was obtained from the Manisa--Demirci region. It was composed of 5-94 percent K_2O, 3-14 percent Na_2O, 0-61 percent CaO, 0-41 percent MgO, 0-11 percent TiO_2, 0-65 percent Fe_2O_3, 15-7 percent A1_2O_3 and 73-08 percent SiO_2 as determined by the XRF technique. Microscopic studies on thin sections revealed that muscovite, biotite, tourmaline, sphene and rutile were disseminated in various sizes ranging between 20-500 mu m in the matrix of orthoclase, albite and quartz, and for an adequate liberation the sample had to be ground to -300 mu m. The non-magnetics were a basic mixture of feldspars and quartz with an alkaline content of 5-86 percent K_2O and 2-96 percent Na_2O, which was raised to 13-44 percent(9-22 percent K_2O + 4-22 percent Na_2O) by only feldspar flotation. For further improvement of Kfl, orthoclase was differentially floated while albite was simultaneously depressed with Nad. Finally, a high-grade potassium feldspar concentrate was produced composed of 12-65 percent K_2O, 3-1 percent Na_2O, 0-11 percent Fe_2O_3 and 0-04 percent TiO_2 with a glossy white firing button ail 200 deg C.