Study On Additives Of Low-cement Refractory-castable

The refractories are the fundamental materials of the high-temperature industry. With the development of the refractories industry, the rate what the unshaped refractories have is becoming bigger increasingly, but among them the appliance of the refractory castables are more and more extensive. The additives play an important role in the refractory castable properties.The influence of the different additives upon the refractory castable properties was studied in this paper aimed at the national present condition of the refractory castables. On the basis of the studies of predecessors, the author studied and generalized the influencing factors on the refractory castable properties, such as, grain composition, micro power, particle appearance, binder and so on, and the basic theories of the surfactants, studied emphasizing the different additives on properties of bauxite-based low-cement castable Besides, compound mechanisms of several composite additives were analyzed.This experiment process can be divided into the non-microsilica system and the microsilica system. Joining different additives in bauxite-based low-cement castables, measuring its flow values, making the materials into the test blocks in order to measure their physical properties after dealt with 110℃x 24h 1450℃x3h heat treatments. The results show that for the microsilica system, the composite effect of STP and PAANa is compared to the composite effect of STP and AS, flow value of the former is bigger than that of the latter;but after dried and heated, the strength of the latter is higher than that of the former;For the non-microsilica system, the composite effect of sodium hexametahposphate(SHP), calcium lignosulphonate and sodium citrate is compared to the others, the flow value of bauxite-based low-cement castables are increased obviously and physical properties areimproved slightly. By the means of XRIX SE1VU EDS, the author analyze the microstructure of the sample, the results show that under the condition of joining the organic additives, their compositions and microstructure have no obvious alternation and have not form big pores. One part of it is carbonized at high temperature. After samples are sintered, their physical properties are improved to some extent. This paper has hereby certain practical value and applied prospect.