Use of Zircon sand in Foundries

Abstract

Zircon sand by virtue of its 1ow expansion, high degree of refractoriness, thermal stability, and non-wetting and inert reactivity towards certain molten metals finds scope as a versatile moulding and ceramic material for high-temperature applications. Zircon sand deposits in India are not as a bund ant as those of silica sand and in any case are not 1ying on the doorsteps of the Indian foundries. It is obtained as a bye-product while processing the Chavara and Quilon beach sands of Kerala State, and Manavalakurichi, Madras State for ilmenite and Monazite. Although no systematic assessment of these reserves has been made, these are expected to be around 350 million tons and the second largest deposit of the kind in the World. Data available at hand indicate that zircon constitutes about 10 percent of the beach sand and on this basis as also from the production figures of ilmenite, the availability of zircon can be estimated to be approximately over 20.000 tons per annum. The increased cost of winning the material from the beach sands of Kerala and transporting it to far off places makes it costlier than silica sand. However, this factor is often overlooked by the foundrymen in view of the distinct advantages and optimum combination of properties offered by zircon over the silica sands.