Abstract:
The purpose of this research is to add value of feldspar slime waste by flotation process. Feldspar slime waste, which is from the main processes of feldspar flotation plant at Attanee International Co., Ltd., Tak province, is 20% percent of the total ore feed with particle size less than 230 mesh (63 microns). Since 1985, company has produced the slime waste approximately around 350,000 tons, causing a huge pile of stock and obstructing the operation area. The mineral compositionscharacteristic of feldspar slime waste using using X-Ray Diffraction (XRD) showed that it consisted of albite, orthoclase, quartz, and impurity minerals such as biotite or black mica. The elementalchemical analysis by using X-Ray Fluorescent (XRF) showed 72.53% SiO2, 15.70% Al2O3, 1.56% Fe2O3, 0.16% TiO2, 0.40% CaO, 0.07% MgO, 4.87% K2O and 4.38% Na2O, which is unsuitable to use in ceramic industries. Then, this slime was conducted to magnetic separation and flotation process to improve feldspars specifications to meet the requirement of ceramic industries. Study of size feldspar slime waste flotation, which is used for removing quartz from feldspar, showed that the optimum condition is at 50% solids and must be adjusted to pH 2 by hHydrofluoric acid (HF), using A-TD as a collector at 2.6 kilograms per ton feed. The results of the study showed that the recovery of feldspar attaineds 79.03% with grading 67.42% SiO2, 18.48% Al2O3, 0.97% Fe2O3, 0.08% TiO2, 0.55% CaO, 0.09% MgO, 6.04% K2O and 5.49% Na2O. The mineral compositions meetthat is suitable for ceramic industrys specifications standard; however the impurity of Fe2O3 is high and required magnetic separation process and flotation. Furthermore, there is the pre-feasibility study of the recovery and value - adding processes of feldspar slime waste by the economic evaluation. This is to guide decisions on initial investment of manufacturer as well.