Technology for Beneficiation of Low-Grade Limestone Containing Finely Disseminated Silica Grains for Utilization in Cement Making Industry.

Limestone finds major application in the manufacture of cement. However low-grade limestone with high silica content is not suitable for this purpose. Utilizing limestone in cement making the total silica content is to be less than 12%. For the effective utilization of available low-grade limestone resources, it is imperative to develop technology to reduce silica below 12%.

Usage of limestone concentrates in the cement making industry. 

Based on the detailed studies on characterization with respect to physical, chemical, mineralogical and beneficiation characteristics, flotation-based process technology has been developed for beneficiation of low grade limestone samples with fine grained silica as the impurity. The important technical features of the technology include the following:

• Separation of fine-grained silica from calcite.
• Reduction of silica content in the sample from 19% to 11%.
• High recovery of CaO of 96%.
• Validation of laboratory results at the pilot scale.
• The technology is suitable for the beneficiation of low-grade limestone for use in cement making

• Meeting the requirement of the construction industry in view of growing infrastructure needs.
• Effective utilization of low-grade limestone deposits and the conservation of resources.