Recycling of refractories from the glass manufacturing industry

Abstract

Refractories present at the end of campaigns of glass melting furnaces are to a large part corroded, infiltrated by glass and/or have reacted to its components. In addition to the refractories heavily contaminated by melted glass and its vaporized or condensated by-products, other refractories are retrieved, often in large quantities, which are only Hghtly contaminated or not at all. Up to now the larger amount of refractories remaining after furnace campaigns have been disposed of and only a relatively small amount re used in the refractory industry (approximately 10%). Recycling of this material is, however, legally imperative, and various lightly contaminated refractories are now being recycled by some companies for re-use as refractories as well as for other applications. This paper will discuss the present situation of recycling refractories retrieved from glass melting furnaces by the glass and refractories industries with the aim of initiating the problem solving process. Based on a recent inventory it will be shown which quantities of which types of refractory materials occur in the German glass industry and with which impurities the refractories can be contaminated. Using a qualitative presentation of the impurities present in the refractories retrieved from different parts of the furnace and different types of glasses, various possibilities for recycling will be discussed. Not yet existant, basic requirements and the necessity of corresponding research will be indicated. Successful and far-reaching solutions of these problems must be the common goal of the glass and refractory industries.