【作者】 孔祥文；

【导师】 涂赣峰； 隋智通；

【作者基本信息】 东北大学 ， 有色金属冶金， 2008， 博士

【摘要】 攀西钒钛磁铁矿经选矿后,原矿中54% TiO2进入钒钛磁铁矿精矿,再经烧结、高炉冶炼与铁水分离,全部进入高炉渣中,形成TiO2含量高达23-24%的含钛高炉渣。至今累积已超过5000万t,并以300万t/a的速度递增。大量含钛高炉渣的堆积不仅浪费资源,占用耕地,而且严重污染环境,急需找到一条有效的利用途径。《攀钢资源综合利用规划》指出：“攀钢是冶炼共生矿石,二次资源的利用,特别是高炉渣、钢渣的利用难度较大,因此,攀钢二次资源综合利用是一项更迫切和重要的任务。”由此提出了选择性析出分离技术理论,并已成功地应用于含钛高炉渣的处理。攀钢每年300多万t高炉渣,30多万t钢渣,全部经选择性析出分离技术处理,将得到90多万t富钛精矿即精矿(TiO2品位在40%以上的富钛相)和180万t贫钛尾矿(TiO2品位在10%以下的贫钛相)。尾矿主体矿物相是含钛的硅酸盐,用作钛原料,TiO2品位偏低不可取,因此寻找有效的、大规模的利用途径是可持续发展的重要保证。利用含钛高炉渣生产建筑材料,可实现含钛高炉渣的大规模利用。本课题从一种全新的角度去利用含钛高炉渣制备新型建筑材料,即用有机聚合物代替无机胶凝材料,配以添加剂,免烧免蒸条件下制备新型墙体砖,以实现含钛高炉渣的资源化利用。本研究工作具体体现在以下几个方面：1.通过不同激发剂对含钛高炉渣活化效果的对比,研究了含钛高炉渣的活性,发现组合碱氢氧化物—氧化物对含钛高炉渣的活性激发效果最好,m(M(OH)n): m(MmOn)=0.75-2.5,试样强度为8.0-12.56 MPa,辅以助激发剂可使试样强度增加到12.27-14.83 MPa。2.研究了以聚醋酸乙烯酯、聚乙烯醇、苯丙乳液和改性废聚苯乙烯乳液为胶凝材料,含钛高炉渣为集料,掺加有机—无机复合激发剂和复合添加剂,制备了含钛高炉渣免烧免蒸砖试样。3.通过对试样强度性能试验,研究了含钛高炉渣免烧免蒸砖试样制备适宜的工艺条件。结果表明,利用上述有机聚合物乳液为胶凝材料制备的含钛高炉渣免烧免蒸砖,其含钛高炉渣掺量均可达到85%以上。4.通过含钛高炉渣免烧免蒸砖试样的外观质量、强度性能、体积密度、吸水率和干燥收缩性能等指标的测试和分析,表明以含钛高炉渣为集料,辅以激发剂和添加剂,聚醋酸乙烯酯、聚乙烯醇、苯丙乳液和改性废聚苯乙烯乳液为胶凝材料制得的含钛高炉渣免烧免蒸砖的各项性能满足墙体砖的基本要求。5.无皂乳液由于在合成过程中不使用乳化剂,消除了乳化剂对环境的污染、产品纯度及性能的影响。将其应用于含钛高炉渣的改性,既可以保持聚合物改性的优点,又能避免乳化剂带来的不利影响。在聚(甲基丙烯酸丁酯/丙烯酸钠)P(BMA/AANa)齐聚物存在下,合成了无皂聚(α-甲基苯乙烯/甲基丙烯酸丁酯)P(AMS/BMA)乳液和(醋酸乙烯酯/甲基丙烯酸丁酯)P(VAC/BMA)乳液,考察了无皂乳液对改性含钛高炉渣免烧免蒸砖试样性能的影响。6.通过X射线衍射(XRD),红外光谱(IR),扫描电镜(SEM)等手段探讨了有机聚合物改性含钛高炉渣免烧免蒸砖的增强机理。结果表明,试样强度主要来源于聚合物和含钛高炉渣中金属离子之间的交联作用。更多还原

【Abstract】 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.更多还原