Defining the optimal mixture composition of geopolymers based on the coal mine waste and the shale.

Nowadays, industry plays one of the main roles in daily life. Extractive industry is one of the oldest industries, present in almost each country. Unfortunately, besides the benefits connected with development of the extractive industry, there are also disadvantages such as enlarging amounts of stored industrial wastes. One of the ideas how to manage with unnecessary wastes is geopolymer, relatively new material which parameters are similar to the parameters of the concrete. The paper shows the following attempts to define optimal mixture composition of geopolymer based on the wastes from the coal mine and geopolymer based on the shale from the post-mining spoil tip. Coal mine waste, shale, powdered glass waste, metakaolin and sand were used as the raw materials. Sodium hydroxide and sodium silicate were used as activators. Mixtures consisting of mentioned components used in different ratios were prepared and poured into small moulds. The compressive strength of samples was tested after 3, 5 and 7 days. From the best mixture, the bigger samples of dimensions 4x4x4cm were prepared and tested after 7 and 14 days. The paper presents characteristics of used wastes, preparation and curing processes, test procedure and finally, compressive strengths and densities of tested geopolymers