Recovery Slime Waste from Feldspar Flotation Plant at Attanee International Co. Ltd., Tak Province, Thailand

Abstract

The purpose of this research is to recover slime waste from feldspar flotation plant at Attanee International Co. Ltd., Tak province. Slime waste with particle size less than 230 mesh, is found about 20% of the total ore feed. Since 1985, company has been producing slime waste approximately 200,000 tons, causing a huge pile of stock and obstructing the operation area. The mineral compositions of slime waste by X-Ray Diffraction (XRD) showed that it consisted of albite, orthoclase, quartz, and ferrous impurity minerals such as muscovite, biotite, mica, and garnet. The elemental analysis by X-Ray Fluorescent (XRF) showed that the percentage of grade contained 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. After that, this slime waste was sent to the processes of dirt washing, classifying, attrition scrubbing, separating the ferrous impurity minerals, and preparing for flotation by washing drum, trommel, attrition scrubber, cone classifier, permanent drum magnetic separator, wet high intensity magnetic separator, and hydrocyclone. At this stage, the slime mainly consisted of albite, orthoclase, and quartz with 74.43% SiO₂, 15.15% Al₂O₃, 0.12% Fe₂O₃, 0.04% TiO₂, 0.43% CaO, 0.01% MgO, 4.73% K₂O and 4.75% Na₂O at a yield 35%. Study on fine feldspar flotation, which is for removing quartz from feldspar, showed that the optimum condition of 20% solids must be adjusted to pH 2 by hydrofluoric acid (HF), using A-TD as a collector at 1,400 grams per ton feed, conditioning time and flotation time of 5 minutes each. The results of the study showed that the recovery of feldspar attained 69.7% with 67.82% SiO2, 18.54% Al₂O₃, 0.14% Fe₂O₃, 0.03% TiO₂, 0.52% CaO, 0.006% MgO, 6.88% K₂O and 6.07% Na₂O, which meet ceramic industry’s specifications.