酯硬化水玻璃砂生产工艺及设备应用

Technology of Ester-hardened Sodium Silicate Sand and Application of Equipment

型砂采用改性水玻璃和酯硬化,选用优质天然硅砂,使水玻璃加入量降低到2.0%,既保证型砂强度,又改善了溃散性。320℃热干法再生,针对水玻璃旧砂的特点设计沸腾床、风选和冷却器,使旧砂的残留水玻璃脱膜率≥50%,残钠≤0.3%。恒温双料桶加料,使液料定量加入,达到单一型砂。除自然损耗外,无废砂排放。

The high grade natural silica sand was selected and the mold sand was hardened by modified sodium silicate and ester, thus can reduce the addition of sodium silicate up to 2.0%. The technology can not only guarantee the strength of the mold sand, but also improve the collapsibility. The sand are reclaimed using hot dry method at 320 ℃. Based on the characteristics of sodium silicate used sand, fluidized Bed, wind selection and cooler were designed, which can make the demoulding rate of retained sodium silicate in used sand improve to above 50% and retained sodium less below 0.3%. The sand are charged using double barrels at constant temperature and the liquid materials are added quantitatively, thus obtain single mold sand. There are no waste sand except for the natural loss.