The traditional aluminothermic reduction of vanadium-enriched slag using metallic Al as a reductant to produce Fe-V alloys causes high production costs and energy consumption. Aluminum dross as a solid waste with strong reducibility is a cost-effective and carbon-free secondary resource. In the present work, an efficient and sustainable recycling method is proposed to recover valuable metals and produce Fe-V crude alloy from vanadium-enriched slag using aluminum dross as a reductant. The influence mechanism of temperature, slag basicity, and reductant dosage on metal recovery during the novel aluminothermic reduction was investigated. The results demonstrated that metal recovery ratios of Fe, Cr, Mn, and V approached the maximum values of 95.6%, 84.2%, 87.9%, and 91.8%, respectively, at a temperature of 1873 K, slag basicity of 1.5, and a mass ratio of aluminum dross to vanadium-enriched slag of 0.44. An alloy with 28.18 wt.% Fe, 6.34 wt.% Cr, 30.47 wt.% Mn, and 35.01 wt.% V content was produced, and the mass ratio of V/Fe in the obtained Fe-V crude alloy product approached 1.24. The novel aluminothermic reduction showed many sustainable and economic benefits, including no carbon gas emission, rapid consumption of secondary resource aluminum dross, and widely-used alloy product.
The decarbonization of heavy industry and the emergence of renewable energy technologies are inextricably linked to access to mineral resources. As such, there is an urgent need to develop benchmarked assessments of the role of critical elements in reducing greenhouse gas emissions. Here, we explore the role of vanadium in decarbonizing construction by serving as a microalloying element and enabling the energy transition as the primary component of flow batteries used for grid-level storage. We estimate that vanadium has enabled an avoided environmental burden totaling 185 million metric tons of CO2 on an annual basis. A granular analysis estimates savings for China and the European Union at 1.15% and 0.18% of their respective emissions, respectively. Our results highlight the role of critical metals in developing low-carbon infrastructure while underscoring the need for holistic assessments to inform policy interventions that mitigate supply chain risks.
采用厚度均为2 mm的Q235钢与5052铝合金板进行CMT电弧对接熔钎焊,研究焊接速度、送丝速度对接头焊缝成形、界面微观组织与力学性能的影响.试验结果表明,在送丝速度为5.6 m/min、焊接速度为0.48 m/min时背部成形良好,钎料在母材的润湿铺展较好.界面处生成了平均厚度小于10μm的金属间化合物层,其成分以针状向钢侧生长的Fe2Al5和靠近铝侧的较为均匀的FeAl3为主.当钎料润湿铺展较好且有背部成形时,接头强度较高,接头在铝母材处发生颈缩,接头承载强度可达158.3 MPa.其余试样均断裂在铝/钢界面处,随着界面处金属间化合物厚度的降低,强度有所提高.铣除余高后,接头强度明显降低,接头最高抗拉强度仅为67.9 MPa.
为了提升废酸浓缩效率,以现场废酸为原料,在实验室采用真空旋转蒸发仪模拟现场废酸真空蒸发浓缩,开展废酸浓缩工艺单因素试验及正交试验,然后以实验室研究结果为依据,在现场开展了废酸浓缩工艺优化工业试验.结果表明,在相同的硫酸浓度条件下,废酸相对纯硫酸密度大,且随着硫酸浓度的增加,两者密度差逐渐减少;随着废酸浓缩时间、浓缩温度及浓缩真空度的增加,废酸浓缩浓度均逐渐增加,影响废酸浓缩浓度的关键影响因素为浓缩时间、浓缩真空度、浓缩时间×浓缩真空度、浓缩温度,重要度排序为浓缩时间>浓缩真空度>浓缩真空度×浓缩时间>浓缩温度.工业试验结果表明,当废酸浓缩时间、浓缩温度及浓缩真空度分别由2.06 h、108℃及30 kPa提升至2.68 h、112℃及45 kPa时,一级浓缩酸浓度均值由29.5％提升至38.5％.研究结果为硫酸法钛白生产企业提升废酸浓缩效率提供了重要的数据及理论支撑.
对国内外钢厂的含锌粉尘综合利用理论及技术进行了分析,火法还原工艺基于以煤为载体的高温碳冶金,能耗高、碳排放量大、污染严重是其难以回避的共性问题,同时还带来次氧化锌回收利用产生的能耗高、环境负荷大等新问题.根据团队以往研究经验,并结合目前国内外对低碳冶炼的新要求,提出了含锌粉尘氢还原低碳排放高值化利用技术思路:通过氢还原,将含锌粉尘中的铁和锌、铅、铋等有价金属还原,还原后的锌、铅、铋以气体形态被氢气载体带走,实现金属铁与有色金属的分离,含氢烟气再通过梯级冷凝分离锌、铅等有色金属.同时开展了含锌粉尘制备球团、氢还原理论和试验、含锌蒸汽分离理论分析及金属铁磁选等研究工作,为该技术思路的实施提供了坚实的基础.新技术有望实现钢厂含锌粉尘的低碳化冶炼,同时还可以得到附加值更高的金属锌及其它金属产品.
