The main aim of this paper is influence of composition samples partially made from recycled silicon carbide on integrity of .products. Since the products are used in the foundry industry, it is necessary to achieve high wholeness and strength of the samples in order to avoid their disintegration during handling. Further restrictions are the requirements of the foundry on the limits of quantity of individual raw materials. Purpose of this research is using silicon carbide waste material and therefore minimalizes of its production and reduces ecological effect on environment by its recycling. A set of measurements simulating the impact of briquettes, with different composition, on concrete from 3 meters was performed, representing the most common way of sample damage in real operation. This series of experiments has been successfully demonstrated that it is possible to accelerate briquette hardening and thus also to increase its workability and primary strength. This change in the physical properties of briquettes was caused especially by replacing part of the cement by other binders on a different chemical base. Minor influence also had shape of size distribution curve of aggregate. On the other hand, various amounts of silicon carbide in the mixture, in the percentages allowed by foundry limit, did not affect the integrity of the sample.