Ever increasing demand for power warrants all possible resources from both the renewable and non-renewable forms of energy. Among non renewable resources petroleum is becoming fast depleted and costly. The same is reflecting on power production. Most of the countries are looking at coal as an alternative source of energy. Quality coal is being diverted to metallurgical processes while the coal with higher ash contents was being diverted for power generation.

The coal of low grades generates huge quantities of ash. The ash with high surface area fly ash is harmful to the neighboring communities causing minor health hazards like skin itching to major ones like silicosis. The ash also damages land and standing crops when it is not stabilized. Therefore, great impetus is given to the research centered on fly ash. India mooted a fly ash mission which thrives hard in generating technologies that produce products of various kinds with fly ash as an integral part of it.

Several organizations and institutions contained terms of their own working on the task of fly ash utilization. The products developed varied from FaL-G bricks to high technology areas like zeolite preparation. Several authors have studied the zeolites obtained from fly ash principally contain fly ash-lime-gypsum.

Composition Ratio

Variable Max Min Ratio Fly ash 80 20 4 Fire clay 50 10 5 Slag 30 10 3 Sodium Silicate Sufficient quantity Sufficient quantity ---

A relationship is presented in terms of crushing strength with other parameters of the study. The effect of slag percentage on determination of apparent water absorption, Bulk Density, Apparent Porosity, Shrinkage Test and Crushing strength are discussed in this paper.