Efficient Recovery of Feldspar, Quartz, and Kaolin from Weathered Granite

Abstract

Weathered granite contains a high concentration of feldspar, quartz, and kaolin. However, while it becomes rich in clay due to strong physical weathering, the granite minerals that are not fully weathered are still very hard, which makes the grinding process more difficult and limits its use. This study proposes a multi-step process involving grinding, desliming, and flotation to address this issue. The study determines the appropriate grinding time and power index for the original ore, as well as the optimal desliming method using a hydrocyclone. To remove iron-containing impurities like mica, a combination of NaOL/BHA/A CO collectors is used for the reverse rough flotation of quartz. Additionally, a combination of DDA/SDS collectors is employed to separate quartz and feldspar through flotation, resulting in a quartz product with a silicon dioxide content of 99.51%. The objective of efficiently recycling feldspar, quartz, and kaolin from weathered granite is accomplished. Additionally, the inclusion of intermediate mineral components as by-products of feldspar and raw materials for aerated bricks is introduced, resulting in the complete utilization of all components. This innovative approach ensures a clean and environmentally friendly process, eliminating the need for solid waste disposal.