Study On The Preparation Process And Mechanism Of Sintered Brick By Using Tailings

The discharge of tailing in china is lager, the amount of tailings has more than 10 billion tons, and however, the comprehensive utilization ratios are low. The Large-scale pile of tailings has threatened the mineral resources, the ecological environment, economy and safety of our country. Utilization of tailings for green building materials can mitigate environmental problems, and provides the theoretical foundation for the efficient utilization of minerals.In this article, the process mineralogy of iron tailing and graphite tailing were analyzed, the preparation technology and the sintering mechanism of preparation sintered brick by using the iron tailings were research, the efflorescence inhibition and coloring mechanism of graphite tailings decoration sintered brick were research.The preparation technology of sintered brick by using the iron tailings were determined, the dosage of iron tailings is 35-45%, coal gangue is 25%, clay is 30-40%, water is 12-13%, the aging time is 2days, forming pressure is 6 MPa, sintering temperature is 900℃～1050℃ and the holding time is 30min. Under this condition, the sintered brick has good color uniformity, conformed to the requirements of the MU20 of national standard GB5101-2003. XRD results show that the minerals of sintered brick are quartz, plagioclase, mica and hornblende after roasting, residual quartz, plagioclase and other components were constitutes the density brick by the cohesive action of vitrification properties.The efflorescence of sintered brick by using graphite tailings is caused by calcium sulphate. The efflorescence of sintered brick were suppressed with addition of 10% silica residue,2% barium carbonate and fining the raw material (d50=10.45μm, d90=43.67μm). The analysis shows that the reaction of calcium sulfate and barium carbonate generated barium sulfate and calcium carbonate, calcium carbonate was decomposition about 825℃, barium sulfate in sintered brick, the particle size of barium sulfate was 1μm, and easy to aggregation.By adding different amount of MnO2, TiO2 and Fe2O3, the graphite tailings decoration sintered brick appeared dark brown, light grey, dark red and pink, and so on. Moreover, the decoration sintered brick has good color uniformity, rich adornment effect, conformed to the requirements of the MU15 of national standard GB5101-2003. XRD results show that, the hematite transformed into bixbyite when the addition of MnO2 is 10%, the TiO2 crystal was stability and no physical and chemical reaction under the sintering temperature of 1000℃, the intensities of the XRD peaks for hematite increased with the increase of Fe2O3.EDS element surface density analysis show that, MnO2 and Fe2O3 has good dispersivity, TiO2 was agglomerated in the local region of the sintered brick.