Process for precoating granular mineral materials with synthetic resin

摘要

The invention relates to a process for coating granular mineral materials with synthetic resin. Minerals of this type, for example quartz sand, zircon sand, chrome ore sand, fireclay and corundum, are used in coated form in foundries as a moulding material (sand) for the production of shell moulds by the Croning process. The invention has the object of providing a hot-coating process which involves adding hot-liquid synthetic resin to the mineral material to be coated, but overcomes the disadvantages of the prior art by allowing rapid change of the synthetic resin types to be processed, allowing inherently reactive synthetic resins to be employed, and generally being more practicable and less complex. This object is achieved according to the invention in that the hot-liquid synthetic resin is only formed just before its addition to the mineral material, by melting solid synthetic resin.