Comprehensive Application Design of Enshi Hard Kaolin Resources and Analyses of Product Performances

Objective To achieve green and efficient resource utilization and development of hard kaolin resources, Method this article takes Enshi hard kaolin as the research object. The process of the comprehensive utilization is designed by combining with the technologies such as ‘optical separation’, ‘selective grinding’ and ‘ore blending and calcination’ based on former process mineralogy researches. The kaolin products are obtained like glass fiber, mullite (M45 and M60) and tailings products (casting-sand ore and cement additive). The properties, such as the composition, morphologies, phases, chemical oxygen demand, bulk density, porosity and water absorption, of the corresponding products are analyzed. The performances of products are compared with those of the domestic and foreign related products. Result The kaolin products for glass fiber in Enshi can be applied as raw materials for roving glass fiber. The Al₂O₃ content in the mullite sample M45 is 52.24%, the bulk density is 2.63 g/cm³, and it contains 84.96% mullite phase. The M60 product has an Al₂O₃ content of 57.48%, a K₂O+Na₂O content of 0.70%, and contains 98.44% mullite phase, all of which can be regarded as second-grade mullite products. Tailings are suitable for use as raw materials for foundry sand and as additives for cement. Conclusion This research achieves the goal of the comprehensive applications with the green, low-carbon and 100% utilization and also provides reference value for the utilizations of similar resources.