GB1115435A - Production of slabs for use in the lining of hot tops and the heads of ingot moulds - Google Patents

Abstract

Slabs of composition suitable for lining the head of an ingot mould are produced by forming an aqueous slurry of granular or powdered refractory, organic fibrous material and a binding agent, placing it in a horizontal slab mould, vibrating to settle the solids and form an aqueous supernatant layer, depositing on the surface of the slurry a dry, heat-insulating composition which absorbs the supernatant layer, compressing, and drying the slab formed after removal from the mould. The refractory may be a silicate, silica flour, olivine, chamotte, alumina, or silica sand or a mixture thereof; the organic fibrous material may be paper pulp, cotton waste, rag stock, nylon fibre, polyester fibre or acrylonitrile fibre or a mixture thereof and the binder may be sodium silicate, a natural gum, urea-formaldehyde resin, phenol formaldehyde resin or furan resin. The slurry may also contain a fibrous refractory, e.g. asbestos, slag wool, metal fibres or ingredients which react exothermically on ignition, e.g. finely-divided aluminium, with one or more alkali metal or alkaline earth metal nitrates, iron oxide and manganese dioxide. The heat-insulating composition may have the same composition as that slurried or consist of granular or powdered refractory, e.g. kieselguhr, vermiculite, perlite, ball mill dust or dolomite, powdered organic absorbent, e.g. sawdust, woodflour or wheatflour and binder.