Abstract
In order to extract quartz, feldspar and mica from unweathered granite, the crushing of granite and the separation of respective minerals were investigated.
The heating and quenching of granite was introduced to its crushing process and was found to be favorable for the recovery of mica by magnetic separation. The measurement of magnetization of mica revealed that the increase of magnetization of mica after heating process enabled the high recovery of mica in the magnetic separation. The theoretical treatment of the above separation data also suggested that the heating and quenching caused the excellent liberation of mica particles and brought about the high grade of mica concentrates.
The tailings of the magnetic separation were subjected to the following flotation with or without hydrofluoric acid, and quartz and feldspar were recovered as the sink and the float of the flotation respectively. The both products were found to contain very few iron impurities, and satisfy the requirements as the raw materials for glass and ceramic industries.
