PREPARATION OF CALCIUM SILICATE FROM LIMESTONE

Abstract

This work deals with the preparation of calcium silicate from limestone.Calcium silicate or wollastonite is a mineral consisting of calcium, silicon and oxygen. Itsmolecular formula can be expressed as CaSiO3 or CaOn.SiO2

It is prepared by various reactions between siliceous material (e.g. diatomaceous earth) and calcium compounds (e.g. lime, calcium hydroxide).The calcium silicatewas preparedat different conditions of (acid concentration, solid percent, leaching time, particle size and sodium silicate concentration)as follows:

-Leaching of lime with hydrochloric acid in order to prepare calcium chloride solution. - Chemical reaction between sodium silicate solution and calcium chloride.

The optimum preparation process which gives extraction percentage (97%) of CaO involves calcination of calcite sample(-2mm)at 1000°C for 2 hr., then dissolved by hydrochloric acid (conc.10 wt. %) for 30 min depending on the amount of 10%solid percent. The X-raydiffraction analysis was used to confirm the formation of calcium silicate.