PROCESSING OF SILICATE MINERALS FOR ITS EFFECTIVE UTILIZATION

Abstract

Silicates minerals are most common rock-forming minerals and make-up approximately 90 percent of the Earth's crust. Silica tetrahedra made up of silicon and oxygen, form chains, sheets, and frameworks, and bond with other cations to form silicate minerals. Generally, silicates minerals are used in paint, paper, ceramic industry, Abrasive materials, electrical and electronics field (as insulating materials) and also a source of fertilizer, if K2O is present. India does not possess any deposit of potassium rich ores. However, India possesses a vast resource of silicates minerals in the form of mica, glauconite, and pyrophyllite and it is mainly found in Madhya Pradesh, Jharkhand, Uttar Pradesh and Rajasthan. These minerals are basically a group of aluminosilicates of potassium, sodium, and calcium (K2O%: 5-12, Na2O%:0-1, SiO2%: 52-60, Al2O3%: 15-20, Fe2O3%, 5-9, MgO%: 1-2). In this thesis, an effort has been made to extract potassium in form of some soluble salt under different routes such as acid leaching, thermal treatment, and mechanical activation followed by leaching. These pretreatments are aimed to increase K solubility related to the modifications in mineral structure and possible exchange reactions of the suitable ions in the system. After the dissolution of K in leach solution, the leach residue utilization is attempted through carbonation processes. It is known that carbonation on alkaline mineral is a convenient way for the conversion of silicates into useful carbonates using CO2 gas. Simple setup carbonation has been used in this work on leach residue to evaluate carbonates formation. The carbonation degree has been confirmed through FTIR, XRD, SEM, and BET surface area.