Glass-ceramics obtained from copper mine tailings and glass cullets

Abstract

Copper mine tailings is one of the most used secondary raw materials. The most common use is in cement industry and as filler in road construction. The area of secondary raw materials utilization offering the greatest potential is in the development of glass-ceramic compositions, where the waste is melted to form a glass, fabricated using conventional glass forming techniques, and subsequently nucleated and devitrified in a controlled manner through heat treatment. The resultant, partially crystallized material offers improved strength, chemical and abrasion resistance. Copper mine tailings was mixed with 30% glass cullets and melted in electric furnace BLF 17/3 at T=1450 °C during t=0.5 h. The obtained glass sample was black, without visible residual gas bubbles. X-ray powder diffraction (XRD) analysis confirmed the quenched melt to be amorphous. DTA and HSM analysis was performed on the previously prepared glass powder. The glass powder samples were pressed in pellets and sintered in an electric furnace at the temperature of 1040 °C for 2h and a glass- ceramics was obtained. Applications for these glass-ceramic materials would include structural products, pipe or pipeliners to transport abrasive or corrosive fluids, alkali-resistant fibers to replace asbestos in concrete products, and use as a matrix material in which radioactive wastes could be chemically incorporated in a stable, nonleachable, solid form.