Research On Preparation Of Macro-Pore Porous Glass Beads Used As Carrier

In this paper the mechanism and operation process of preparing porous glass material by means of filling method are studied, then the macro-pore porous glass beads commonly used as carrier material are introduced and produced with an improved method of traditional filling method.Beginning with the analysis of the effects, which are brought by the application of only one kind of pore-former and some other operating factors (such as sintering temperature, warmth retaining time and so on), on the properties of the beads, e.g., porosity, strength, size distribution of the beads and pores size, etc., these effects are discussed in detail and the relationship between the factors is studied thoroughly.The use of MPF (multi-pore-former) is introduced for the first time, which is of the most importance and significance in this paper. Through the improvement to traditional means of filling, macro-pore porous glass beads are directly prepared without enlargement of the pores size. As showed by the results, MPF is advantageous for the stable formation or growth of pre-sintered glass beads, and it can partly guarantee the desired' results of sintering. Furthermore, the shape of product is uniform, pores with relatively large size are evenly distributed, and the strength and porosity are all improved to a certain extent. The preferred ranges ofoperation variables are presented on the basis of quantities of experiments, and additionally, the optimized proportion of MPF and suitable operating conditionsare determined: retaining temperature about 800C for 2 hours, with the MPF content of 26.7:16.6 percent, good carrier beads with pore size range 60~180um, porosity above 40%, strength above 3.6Mpa can be obtained.Furthermore, referring to the literature and considering the specific experimental conditions given by the research, expression of the change of feed rate with time is presented, to obtain the linear growth of the diameter of pre-sintered glass beads, thus the distribution of beads size is relatively well controlled and raw material is spared in some extent. Eventually, during the experiment discrete change of feed rate is implemented, and the practical changes of average diameter are plotted, then the results are compared with the theoretical calculated data. As confirmed by the comparison, the model, which describes the continuous changes of feed rate, can be used to predict the practical industrial production of macro-pore porous glass carrier beads.