Use of Triboelectric Techniques for Separating Feldspar from Quartz

The paper shows the results of an investigation carried out to enhance the value of two commercial products currently destined for ceramic industry and to beneficiate the nonmagnetic fraction of a granite quarry waste, applying electric separation techniques based on triboelectric charging and the use of a free-fall chamber. The test conducted on the kfeldspar/quartz commercial product, with 5,7 % K2O content, shows that is possible to obtain a 9,7 % feldspar concentrate and a quartz product with less than 1% K2O content, preheating the feed, without the use of additives. As concern granite quarry waste, the results obtained without the use of additives and pre-treating the feed material with HF and NaOH solutions are compared. It has been found that the pre-treatment with the above mentioned reagents enables to obtain marketable feldspar and quartz products.