Utilization of tailings from tungsten mine waste as a substitution material for cement

This paper presents the feasibility of incorporating tailings from tungsten mine waste (TTMW) and ground granulated blast-furnace slag (GBFS) in the development of mortar with acceptable properties. TTMW has been accumulating for several decades in Sangdong, a region in Korea, and there is a growing demand for alternative uses for this hazardous substance. In particular, the use must be in accordance with the hazardous materials stipulations under the Korean waste control act. This study showed that TTMW presented pH of 8.0–9.3, 18.7–22.0% of water content, 2.6% of maximum ignition loss and 10–30 μm of average particle size. The chemical composition of TTMW showed minute differences from each depth of sampling that represented approximately 50% of SiO2 and 13% of both Al2O3 and Fe2O3. The chemical composition of Cd, Cu, Zn and Pb from mortar incorporating TTMW showed lower levels of hazardous materials which met the specifications of the waste control act in Korea. The TTMW-mortar also appeared very effective for stabilizing/solidifying heavy metals particularly when used in conjunction with GBFS. The study showed that increasing the TTMW content in mortar mixes decreased both flowability and compressive strength. However, the flow value was improved somewhat when GBFS was added. Overall, the investigation suggests that mortar with acceptable properties can be developed using moderate volumes of TTMW (up to 10% by mass).