Liquid self hardening mixture for making casting moulds

摘要

Mixture is produced by mixing a filler with a binding agent, a foam former, hardener and water. Added to the mixture as binding agents are materials containing the salts of sulfo-lignin acids. For hardening the binding agent compounds of the hexavalent chrome are added. More specifically the following ingredients (in wt.% of the total mixture) are included: quartz sand 83.0 - 91.0 refractory clay 0 - 8.0 materials with a salts of sulfo-lignin acids content (aqueous solution with a 45.0 - 55% dry. substances concentration) 2.7 - 8.2 combination with hexavalent chrome 0.09 - 1.4 foam former 0.09 - 0.6 catalyst acid 0 - 0.55 water up to 5.0 Advantage: hardening takes place simultaneously throughout and the mould (core) can be used within 30 - 60 minutes.