硅微粉的品质对浇注料物理性能影响的研究

Study on the influence of silica powder on physical properties of castable

通过化学分析、XRD和SEM等手段分析了3种硅微粉的品质,并应用于矾土浇注料,对制备的浇注料进行了性能对比。结果表明:1)a、b、c 3种硅微粉随着二氧化硅含量依次降低,杂质含量、灼减和pH值依次增大,球体发育程度依次降低。硅微粉中杂质元素主要包含钾、镁、铁以及钠等。主要物相均为二氧化硅不定形相和少量霞石类矿物。2)硅微粉a可明显改善矾土浇注料的流动性,浇注料可施工时间长,虽养护24 h后脱模强度略低,但经烘干和高温热处理后试样强度与另外两种硅微粉制备的试样强度相当;硅微粉c施工性能较差,浇注料黏性大,但硬化快,这和pH值以及可溶性的钾、钠等碱盐的含量高有关。

In this paper,the characteristics of three kinds of silica powder were analyzed by means of chemical analysis,XRD and SEM,and the properties of the castables were compared.The results showed that firstly,the impurity contents,ignition losses and pH values of the a,b and c type silica powder increased as silica content decreased,the development of sphere decreased.The impurity elements in silica powder mainly include potassium,magnesium,iron and sodium.The main phases are amorphous silica and a small amount of nepheline minerals.Secondly,the fluidity of bauxite castable can be obviously improved by silica powder a,and the castable can be constructed for a long time.Although the demoulding strength is slightly lower after curing for 24 hours,the strength of the sample after drying and high temperature heat treatment is equivalent to that of the sample prepared by the other two kinds of silica powder;the workability of silica powder c is poor,and the castable has high viscosity,but it hardens quickly,which are related to pH value and the high content of soluble alkali salts such as potassium and sodium.