铬盐多元复杂溶液铝钒同步分离与资源化新过程的基础研究

Chromate is an important basic raw materials of inorganic chemicals. Chromate production process generated large amounts of refractory Cr6+-containing aluminum hydroxide residue and Cr6+-containing calcium vanadate residue due to their characteristics such as high toxic Cr6+, low vanadium content and so on. This project focused on the problem of high environmental risk and resource waste of aluminum and vanadium of the Cr6+-containing aluminum hydroxide residue and Cr6+-containing calcium vanadate residue, to investigate the fundamental research of novel process of synchro-separation and resource utilization of aluminum and vanadium by synthesizing γ-AlOOH and utilizing its interface structure characteristics to coupled remove vanadium in the aluminum removal process of Na2CrO4-NaAlO2-NaVO3-H2O solution, based on the discovery of interaction relationship between aluminum and vanadium. By solving the key scientific problems such as interface structure design and regulation mechanism to synthesize the mesoporous structure γ-AlOOH with large specific surface area, and controlling the anionic coordination polymer of solution to select adsorbing vanadium, the aluminum and vanadium were synchro-separated by synthesis of mesoporous γ-AlOOH with large area and its selective adsorption of vanadium ; combined with the follow-up desorption and modification process, high value-added γ-AlOOH and vanadium oxide products were produced. At last, source reduction of the Cr6+-containing aluminum hydroxide residue and Cr6+-containing calcium vanadate residue and resource utilization of aluminum and vanadium were realized. This project thus provided a theoretical support to solve the green upgrade of the chromate industry.

铬盐是重要的无机化工基础原料，但铬盐生产主流工艺铝钒脱除过程分别产生大量的含铬铝泥和含铬钒酸钙渣，因其含毒性重金属六价铬、钒含量低，难以利用。本项目针对含铬铝泥和含铬钒酸钙渣堆存放置环境风险高、铝钒资源浪费等问题，基于铝钒相互作用关系的发现，在铬盐多元复杂Na2CrO4-NaAlO2-NaVO3-H2O溶液除铝过程中，合成γ-AlOOH 并利用其界面结构特性耦合脱除钒，开展铝钒同步分离和资源化新过程的基础研究。针对这一新课题，通过系统研究γ-AlOOH合成机理及其界面结构调控规律、溶液阴离子聚合形态控制选择性吸附钒的机理等关键科学问题，合成大比表面介孔结构γ-AlOOH并进行钒的选择性吸附，同步脱除铝钒；进一步经后续脱附、改性制备出高性能拟薄水铝石和钒氧化物产品；实现含铬铝泥和含铬钒酸钙渣的源头削减和铝钒资源高值化利用，为我国铬盐工业绿色化升级提供理论支撑。

针对铬盐生产过程含铬铝泥和含铬钒酸钙渣堆存放置环境风险高、铝钒资源浪费等问题，本项目建立了铬盐碱性溶液铝钒同步脱除新方法。揭示了界面结构设计与调控合成大比表面介孔结构γ-AlOOH的规律，突破了铝酸钠溶液硫酸中和水解过程的氢氧化铝胶体沉淀-溶解平衡，建立了铝酸钠溶液硫酸快速中和制备羟基铝新方法。掌握了溶液阴离子配位聚合物控制选择性吸附钒的机理，首次实现铬盐碱性浸出液中和除铝过程中钒的同步高效脱除。基于上述关键科学问题的突破，形成了铬盐生产中铝钒连续化同步脱除新技术及专有装备，，从源头上消除了含铬钒酸钙渣，含铬铝泥源头减量22.9%。新方法应用了7万吨铬盐产能，铝脱除率大于99%，钒脱除率大于97%，生产成本降低1644万元/年，含铬废渣源头减量7000吨/年，铬渣年排放量降低10%以上。该技术工艺简单、指标先进、应用性强，有利于促进铬盐行业降本增效和清洁生产。.该项目形成的方法和技术对铬行业降本增效、铬渣的源头减排具普遍意义，可将我国主流铬盐无钙焙烧生产技术（30万吨/年，占总产能75~80%）的铬渣吨产品排放量降低10~15%。未来，预计可继续推广15~18万吨，覆盖行业主要生产企业。基于该项目形成的强化中和除铝新方法，对于其他湿法冶金碱性浸出体系中杂质铝的绿色分离和高值化具有借鉴意义。.该项工作已完成技术鉴定1项，由石油化工联合会组织的以韩院士为组长的专家组鉴定意见为国际领先，建议加快推广应用；发表论文20篇，申请专利3份。