The Study Of Preparing Conditions And Physicial Performance On Reliance Of High Alumina Castable

This article systematically researches the preparing conditions of high alumina castable to enhance its physical performance .The preparing conditions include aggregate composition, powder, micropowder, binder, additive , water amount for moulding, vibrating time and frequency, etc. The link between preparing conditions and physical performance is achieved, and the optimal composition of high alumina castable is attained , and finally the best economic using effect is reached.The research results are following:(1)The impact of aggregate kinds on the castable strength and density is mainly determined by its dynamics and sinterability. The impact of aggregate kinds on the flowability is less than that of particle form and superface surface property. The affregate composition has a great influence on the flowability, strength and density of the castable. When the aggregate composition is 8-5mm:5-3mrn:3-lmm=10:20:20, the castable gains a better performance .And when using mullite and special bauxite together ,the comprehensive effect is the best.(2)The impact of kinds on the castable flowability is more than that of particle kinds .The best is alundumpowder, then is the mullite ,and the worse is special bauxite, and the fireclay is too cling to be formed. The impact of powder kinds on castable strength and density is similar with that of aggregate kinds. So the mullite powder is better.(3)The influential low of cement on castable flowability is following; the flowability increases with the growing alumina mark of the cement .When using CA70 as the binder, the castable performance is better and the proper adding amount is about 5%.(4)When microsilica and micropowder is added, the flowability and sinterability will be improved and the castable strength will be significantly enhanced.(5)When kyanite is added the castable ratio of linear variation will be significantly improved.This is mainly because of the effect of volumetric expansion which occurs when kyanite powder is transformed into mullite. When the adding amount of kyanite is 4-5%, the castable performance is better.(6)When using sodium tripolyphosphate and sodium hexametaphoprate together as the water reducer the effect of water reducing and dispersing is thebest. And the sodium trijpolyphosphate can be used only ,of which the proper adding amount is 0.2%.While the water amount for moulding makes the castable flowability increase, the water amount also imposes a bad influence on the castable strength and density. So the water amount must be limited between 6.0-6.5%.(7)When the castable vibrating time is about 2mins and the vibrating frequency is about 2900-3000 times/min, the castable performance is better.