Phosphate rock waste in the production of cement tile

Abstract

One of the main concerns of the mining industry is the large amount of waste generated in mineral extraction and processing. Besides causing environmental impacts, these environmental liabilities occupy extensive areas and can lead to problems in their disposal. The use of such waste in civil construction has shown promise through several research. This paper proposes the incorporation of waste rock (WR) from a phosphate mine in the production of cement tiles as a partial replacement for Portland cement. Physical and chemical tests characterized the WR. The cement tiles were developed with the replacement of cement by WR with a content of 25% at temperatures of 400 °C and 600 °C. Hydraulic tiles were developed by replacing cement with WR at a content of 25%. The pieces were produced with WR without heat treatment and treated at temperatures of 400 °C and 600 °C. The tiles were evaluated according to some parameters, such as visual and dimensional analysis, water absorption, acid attack, and strength. As a result, all tiles presented strength above 3.5 MPa, within limits required by the standard. The tiles calcined at 600 °C showed the best pigmentation. The heat treatment did not influence the strength, although it helped in the pigmentation process. Therefore, it was possible to obtain cement tiles pigmented using mine waste with reduced Portland cement consumption, adequate strength, and aesthetically suitable.