Study Of Using The Silica Fume As Rubber Filling To Instead Of White Carbon Black Partially

It is micro silicon powder that is also known as silica fume and condensed silicafume, which English name is silica fume. The recovery of this dust is obtained fromsilicon metal and silicon alloy smelting. The average particle size of micro siliconpowder is0.15to0.20μm, which specific surface area is15to20m2/g. Its maincomposition is SiO2, that content is usually80％to92％. Due to high activity, tinyparticles, large specific surface area, excellent physical and chemical properties, alsoamorphous of SiO2in the silica fume, although used to be as a kind of industrial waste,silica fume is regarded as a valuable resource now increasingly. This powder can be usedfor cement, refractory materials and rubber filling areas.The main content of this article is as follows:In chapter2, combined the test results of carbon content in the micro silicon powdercomposition and structure test, the test results of whiteness,with XRD analysis resultsunder different calcinations, it is concluded that the late trials required temperature is600℃. In order to make the micro silicon powder can be calcined fully, because of thecourse of micro silicon powder calcined in box-type resistance furnace, we shouldincrease the calcination reaction to make the reaction of free carbon completely. Finallythe best calcining purification condition of micro silicon powder as follows: aircondition,600℃calcinations,4h.Liquid phase chemical purification has no significant effect to the raise of whitenessof micro silicon powder, so only calcined under oxidizing atmosphere is for thepurification of micro silicon powder, without liquid chemical purification.In chapter3, the surface modification will be carried on in order to make thepreparation product can be used as a rubber filler. The best technology of micro siliconpowder modified as follows: according to the mass ratio, M(micro silicon powder):M(modifier)=100:5, M(micro silicon powder):M(dispersant)=100:3(dispersantis sodium dodecyl benzene sulfonate). We weigh micro silicon powder, modifier anddispersant respectively, then put three kinds of raw materials and anhydrous ethanol intoa high-speed dispersion machine, after that beat5minutes,20％is slurry concentration.Put above slurry into water bath pot with40℃,1h.In the forth chapter, the rubber packing use performance test has been done on theunmodified and modified micro silicon powder. Comprehensive performance test resultssuggest that the best micro silicon powder in rubber modified content is: the mass ratioM(rubber):M(micro silicon powder)=100:75.Its discusses that liquid phase process of preparation of white carbon black under thelaboratory condition in the fifth chapter. The optimum technological condition is statedbelow: SiO2: NaOH mole should be controlled at0.85:1, the temoerature of thepreparation of sodium silicate more higher, the conversation rate more better. We shouldcontrol speed above30(per second), temperature of water is90℃or so. The quality ofwhite carbon black is the best under that condition, the largest specific surface area, thehighest whiteness.