水玻璃砂VRH—CO_(2)硬化法的研究

Study on VRH-CO_2 Silicate Process

通过试验找出了水玻璃砂ＶＲＨ－ＣＯ２硬化法的真空度与型砂强度及脱水率的关系，发现在真空脱水时，真空室内有一个降温过程，在本试验条件下的最大降温达１１℃。用扫描电镜观察到ＶＲＨ－ＣＯ２硬化法的水玻璃粘结膜是由小耐均匀的硅酸胶粒所组成，耐普通ＣＯ２硬化法的水玻璃粘结膜是连片的硅酸凝胶结构。提出了玻璃砂ＶＲＨ－ＣＯ２硬化法的真空度以１．３３－３ｋＰａ为宜，并指出了ＣＯ２吹气量及保持时间，原砂质量及残...

The relationships between the vacuity and the dehydration rate and the sand strength to the VRH-CO2 silicate process have been found by experiments.The drop in temperature during the vacuum dehydration was discovered in vacuum chamber, the maximum value of which is up to 11℃ under the experimental conditions. The bond film of sodium silicate is found to be made of fine and uniform particle of silica gel for VRH-CO2 process by electro-microscope, but the bond film of silicate-CO2 process is flat silica gel. The suitable vacuity of 1.33-2.0kPa for VKH-CO2 silicate process is proposed. It suggested that the amount of CO2 gassing time, the quality of sand, the retained moisture in moulding sand and relative humidity of euvironment have a substantial influence on the strength of moulding sand.