Research On The Impact Of Minerals And Particle Size On The Content Of Free Calcium Oxide And Petrographic Structure

The impact of minerals and particle size on burnbility and petrographic structure was researched in this paper. Raw materials with different mineral compositions and different particle size were prepared. Chemical analysis, laser particle size analysis, X-Ray diffraction, reflection microscope was used to analyze chemical composition, particle size distribution, the content of f-CaO, and petrographic structure. The impact of raw materials with different proportions of kaolin and bentonite on burnability and petrographic structure was researched. In addition, the impact of coarse quartz, calcite and the change of content on burnability and petrographic structure was studied. The study shown that:1) Clay minerals such as kaolinite and montmorillonite, own better burnability. The more quartz was replaced, the better burnbility would be. Burnt at1400℃, the f-CaO content of clinkers which prepared with kaolinite and montmorillonite, were less than0.60%. But the bunability of raw material with quartz was worse. The f-CaO content was1.96%.2) While mixing same content of coarse quartz, compared with clinker which was prepared with montmorillonite, the f-CaO content and porosity of clinker which was prepared with kaolinite was smaller than the one prepared with montmorillonite, the sintered density was30percent larger.3) Under the same particle size condition, the impact of quartz on burnability was greater than calcite. As the content of80μm sieve residue of calcite increased1.00%, the content of free CaO increased0.04～0.06%,while the content of free CaO caused by quartz increased0.34～1.90%. The influence of quartz was8to30times the calcite. As the content of200μm sieve residue of calcite increased0.50%, the content of free CaO increased0.19～0.55%, while the content of free CaO caused by quartz increased0.31～1.66%. The influence of quartz was2to3times the calcite. Calcite causes mineral nests of f-CaO, the nest size was smaller than calcite size. Coarse quartz caused ring-distributing Belite nests, forming free CaO which spread between Alite.4) Studying on the productive raw materials, the result shown that:When the raw meal contained more kaolin, more high-silica sandstone would be needed. The quartz in the high silica sandstones was difficult to grinde, so the raw meal contained many coarse particles of quartz, bringing about high f-CaO content of clinker. What was more, ring-distributing Belite and f-CaO nests could be found on petrographic structure. The content of f-CaO and ring-distributing Belite nests of the clinker which was made from raw material with less coarse particles was less.5) After being grinding again in different minutes, with the decrease of particle size, the f-CaO content of clinkers decreased dramatically. The f-CaO content declined3-7%. The amount and size of ringlike Belite and f-CaO nest decreased. The distribution of clinker minerals were more homogeneous. If the80μm sieve of raw material reduced to11～13%, the f-CaO content of the clinker calcined at1350degrees Celsius was less than the f-CaO content of the clinker which was made from raw material contained14～15%80μm sieve, burnt at1400degrees Celsius. The impact of fineness on burnability was greater than the impact of calcination temperature.