| 54% of titanium dioxide exists at the iron concentrates after the magnetic of retrieving vanadium and titanium magnetite in Panzhihua. When iron concentrates are smelted, most of titanium dioxide loses in the smeling iron slag in the form of several kinds of totanium compoud to form blast-furnace slag containing 23-24% of titanium dioxide, which was over 3.0 million tons annually for the discharge and 50 million tons of the accumulative discharge in the past years. It wasted resource, occupied territory and polluted seriously environment. The urgent task at present is to explore effective paths for utilization of Ti-bearing blast-furnace slag. Resource comprehensive utilization project of Pangang points out that smelting vanadium and titanium magnetite at Pangang and second resource comprehensive utilization are difficult, utilization of blast-furnace slag and steel slag is more. Second resource comprehensive utilization at Pangang is more urgent and important task. Therefore selective separation-out was proposed and successfully applied to utilization of Ti-bearing blast-furnace slag. Annual yield 3.0 million tons of blast-furnace slag and 300,000 tons of steel slag annual yield at Pangang all are treated by selective separation-out to form over 900,000 tons of titanium dioxide-rich iron concentrates and 1.8 millions tons of titanium dioxide-poor tailings. The tailings are not suited as titanium raw, the dominant mineral phases of which are containing titanic silicates and titanium dioxide is low-grade. It is an important guarantee of sustainable development to explore an effective and comprehensive utilization in scale of Ti-bearing blast-furnace slag.In order to realize comprehensive ultilization in scale of Ti-bearing blast-furnace slag, the non-autoclaved and unburnt bricks were prepared by using Ti-bearing blast-furnace slag as aggregate, polymer emulsion as cementing materials and admixtures. The research work incarnates concretely in the following aspects:1. The activation of Ti-bearing blast-furnace slag was studied by comparing the active effects of different activators. The results show that the active effects of M(OH)n-MmOn on Ti-bearing blast-furnace slag were best. Compressive strength of the sample was 8.0-12.56 MPa with m (M(OH)n):m(MmOn)=0.75-2.5 and was increased to 12.27-14.83 MPa when activating aids were added together.2. The non-autoclaved and unburnt brick was prepared by using Ti-bearing blast-furnace slag as aggregate, polyvinyl acetate, polyvinyl alcohol, styrene-acrylate emulsion and polystyrene emulsion as cementing materials and compound activators and activating aids as admixtures.3. The optimum conditions for the preparation of the non-autoclaved and unburned brick by modifying Ti-bearing blast-furnace slag with polymer emulsion were studied, and in the mixture, mass fraction of Ti-bearing blast-furnace slag reaches to 85%.4. The main properties of brick such as exterior quality, strength, volume density, the rate of water-absorbing and dry contractibility, etc. were examined, it proved that properties of Ti-bearing blast-furnace slag brick modified meet the basic needs of wall brick.5. Because soap-free polymer emulsion was prepared without emulsifying agent, effects of emulsifying agent on the quality and properties of the emulsion products and environment were advoided. Modifying Ti-bearing blast-furnace slag with soap-free polymer emulsion can retain its advantage and avoid disadvantage of emulsifying agent. New soap-free poly (polyvinyl acetate/butyl methacrylate) P(PVAc/BMA) and poly (a-methyl styrene/butyl methacrylate) P(AMS/BMA) emulsion were prepared in the presence of the sodium salt of poly (butyl methacrylate/acrylic acid) P(BMA/AANa) oligomer. Effects of the soap-free emulsion on properties of the non-autoclaved and unburnt brick sample were studied.6. Modification mechanism studied by virtue of XRD, IR and SEM showed that the acid radicals in polymer emulsion react with the metal ions in the slag to form complex compounds.
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