Recent Advances in the Reutilization of Granite Waste in Various Fields

Quarrying and processing of granite produce large amounts of waste residues. Besides being a loss of resources, improper disposal of these wastes results in pollution of the soil, water and air around the dumpsites. The main components of granite waste are quartz, feldspars and a small amount of biotite. Due to its hard and dense texture, high strength, corrosion resistance and wear resistance, granite waste may be recycled into building materials, composite materials and fine ceramics, effectively improving their mechanical properties and durability. By using the flotation process, high value-added products such as potash feldspar and albite may be retrieved from granite waste. Also, granite waste has the potential for application in soil remediation and sewage treatment. This review presents recent advances in granite waste reutilization, and points out the problems associated with its use, and the related countermeasures, indicating the scale of high value-added reutilization of granite waste.

Felsite in Ceramic Materials Production

This project is devoted to the study of the felsite properties for the purpose of its application in the production of various types of fine ceramics: ceramic tiles, acid-resistant tiles, aluminosilicate proppants, etc. Felsite is a mixture of quartz (about 40%) and feldspars. In the compositions of ceramic masses, felsite can play the role of both nonplastic due to the quartz content, and flux due to the content of feldspars, that reduces the amount of mixture components. When felsite is fired, the melt appears at a temperature above 950°C. The felsite has a sintering effect when fired at a temperature of 1000°C. Glass phase enriched with SiO2 ensures the absence of material deformation after firing. Also, glassy phase provides high-acid and chemical resistance of materials based on it. In addition, after firing above 1150°C, felsite has a light color, which is a great advantage in comparing it as a melt with other iron-alkali-containing materials. Ceramics based on felsite does not require the use of opacified glazes.