硅微粉pH值对高铝质低水泥浇注料性能的影响

Effect of pH value of silicon powder on performance of high-alumina low-cement content castable

研究了硅微粉pH值、草酸和柠檬酸对高铝质低水泥浇注料的流动性、硬化时间和常温力学性能的影响。结果表明,硅微粉pH值在5.5～8.5之间,高铝质低水泥浇注料可以获得良好的流动性;随着硅微粉pH值的增大,浇注料的硬化时间缩短;当硅微粉呈弱碱性时,浇注料强度最好。草酸和柠檬酸的加入对浇注料的流动性影响不显著,但会明显延长硬化时间,减弱流动值的衰减,延长可施工时间,其中柠檬酸的效果比草酸显著;酸性物质的加入降低了浇注料110℃的强度,而1 100℃的强度则有所提高。

The effect of pH value of silicon powder, oxalic acid and citric acid on the fluidity, hardening time and mechanical properties at room temperature of high-alumina low-cement castable were studied. The results showed that the high-alumina low-cement castable would get a good fluidity when the pH value of silicon powder was 5.5~8.5. The hardening time would be shortened with increasing of pH value of silicon powder. The castable would get the best strength when the silicon powder was in weak alkaline state. The addition of oxalic acid and citric acid had little effect on fluidity of castable, but would prolong hardening time of castable significantly, weaken flow value attenuation, and prolong pot life. The effect of citric acid was more significantly than oxalic acid. The strength of castable under 110℃ would decrease for the addition of acidic material, however, the strength of castable under 1 100℃ would increase.