Papers by Keyword: Molten Slag

Abstract: According to the phase diagram of the CaO-SiO₂-TiO₂ drawn by FactSage software, the structure units of molten slag were confirmed. The activities of CaO, acid oxides and complex oxides in molten slag were calculated by the model. The effects of slag basicity and of temperature on activities of components were analyzed. The results show that slag basicity is the primary influencing factors.

Abstract: The raw materials from household garbage and industrial waste have increased its usage in the concrete and cement industries. These eco-materials have helped the environment, avoiding pollution, land filling or burning of waste and the usage of other natural resources. However, the cost of many eco-materials is still higher than that of common natural materials. It is necessary to study in detail its behavior and properties to decrease its cost and increase its performance. This research deals with Eco-cement and molten slag aggregate which main raw materials are household garbage and industrial waste. Concretes produced with Portland cement and Eco-cement were mixed with gravel, limestone, quartz and molten slag aggregates to compare its properties. The fracture energy, strength and modulus of elasticity tests were performed and discussed in this paper. The concretes produced with Eco-cement and molten slag aggregate show better results than those produced with Portland cement and natural aggregates.

Abstract: The corundum based material was prepared, with fused white corundum, commercial SiC powder and superfine Al2O3-SiC powder synthesized from clay by carbothermal reduction reaction as raw materials. The influences of SiC and Al2O3-SiC powders on the slag penetration and corrosion resistance of the material were investigated, and the slag resistance mechanisms of the additives were also discussed. It was found that the slag resistance of the corundum material by adding Al2O3-SiC and SiC powders could be improved obviously. For improving the slag resistance of the corundum material, adding Al2O3-SiC was much better than adding commercial SiC. When the Al2O3-SiC powder contacted with the molten slag, Al2O3 in the additive could be dissolved into the molten slag immediately, while SiC remained, which caused the viscosity of molten slag to be increased. So, the slag penetration and slag corrosion into the corundum material could be effectively inhibited.

Abstract: At present, molten blast furnace slag is quenched rapidly using a large amount of water to produce a glassy-granulated slag without any recovery of its much sensible heat, polluting water and atmosphere. To solve these problems, a new heat recovery system is proposed. This system consists of melting gasifier, the 2nd gasifier and boiler in order to achieve stepped energy using. The melting gasifier and the 2nd gasifier use the endothermic heat of gasification reaction instead of sensible heat to recover the energy of molten blast furnace slag. The possibility of the new heat recovery system is studied. The reactions in melting gasifier are studied using STA409PC thermal analyzer and HSC chemistry software. The economic and environmental benefits are calculated based on the heat and mass balances. The results indicate that this method is possible and better than conventional methods such as hot water or steam production. The molten BF slag acts as not only thermal media but also good catalyst. The efficiency of melting gasifier is high and without pollution. Besides, this method can bring huge economic and environmental benefits which are important to the survival and sustainable development of iron-steel enterprises.

Abstract: Porous plate with bimodal size distribution was prepared using the molten slag from the incinerator. The slag was pulverized to 1-10μm using a planetary ball mill. On heating the pellet formed with this powder, its relative density at 750°C and 800°C were 70% and 85%, respectively. At 750°C, each particle partially attached together at the contacted point. At 800°C, however, all particles melted, coagulated together and increased their size. The slag powder was granulated using a tumbling granulator, resulting granules of 0.5-5mm size. The compressive strength of the granule sintered at 750°C was 0.39 kgf. The density of the granule decreased by ~60%. The sintered granules were mixed with a proper amount of glass powder and starch water, and the slurry was cast to a mold (φ80mmx10mm). After drying the cast plate, it was heated at 630°C. The density of the plate was 1.2 gcm-3, ~43% of original slag value. The sound absorption coefficients of the plate were 0.02 and 0.4 at 200Hz and 1500Hz, respectively.