Moulding sand recovery improving quality of sand - using thermal treatment and mechanical action to recycle sand with reduced energy consumption

摘要

To recover used sand from a casting assembly, for further use, the thermal treatment for the sand grains is applied at 310-900 deg. C. The sand grains are classified and worked mechanically in cycles with a grain movement speed of 5-50 m/s. At least one of the cycles is in a watery medium, with a sand grain movement speed of 5-7 m/s. The sand grains are given a mechanical handling action in a watery medium after a thermal treatment at 310-490 deg. C. A mechanical action can be applied before and after the thermal treatment at 700-900 deg. C, using a watery medium before the heat treatment, and an air medium after the heat treatment at a grain movement speed of 30-50 m/s. ADVANTAGE - The method increases the quality of regenerated sand and reduces energy consumption and extends the life of sand used for hot box casting. It also reduces the losses of fresh sand, bentonite and carbon to save natural resources and transport while protecting the environment.