| 摘要 |
<p>Attrition reclaimed ester-cured phenolic resin bonded sand is subject to thermal treatment prior to re-use. Prior to the thermal treatment, however, the attrition reclaimed sand is contacted with an additive which converts potassium compounds to a form having a melting point of at least 550 °C and the thermal treatment is effected at a temperature below that at which the resulting potassium compound fuses.</p> |
