Feasibility of Using Lead–Zinc Tailings to Produce Environmentally Friendly Ceramisite

Abstract

There are large volumes of lead-zinc tailings (LZT) produced in China and elsewhere in the world. LZT disposal to the landfill is problematic and causes many environmental issues. The objective of this work is to demonstrate how LZT can be effectively used to produce ceramisite. The experimental results show that the LZT alone is not suitable for making ceramisite. When mixed with clay, it can be turned into ceramisite with ideal properties for building applications. The optimization test results reported herein show that priority order of factors affecting the compressive strength of cylinder samples is, in turn, sintering temperature (B)> sintering time (C) >LZT content (A). The order of factors influencing the density is C>A>B. The results show that the leaching content of Pb and Zn of all sintered ceramisite samples is far less than the limit values of hazardous components in the leachate specified in the relevant standard. The optimum combination of parameters to produce ceramisite is 50% LZT content, at sintering temperature of 1,150°C and sintering time of 9 min. Under the optimum conditions, the compressive strength and apparent density of ceramisite have reached 9.9 MPa and 1.12 g/cm3 respectively. The results indicate that ceramisite can effectively be made using LTZ for civil engineering applications.