有色金属冶炼渣液相催化氧化同步脱硫脱硝

The treatment of nonferrous metal smelting fuel gas is with great difficulty. The removal of sulfur dioxide and nitrogen oxide from an economic perspective is urgently needed to meet the increasingly stringent environmental regulations of exhaust gas emission. The nonferrous metal smelting slag is a typical bulk industrial solid waste with environmental impact and hazard. Therefore, the comprehensive utilization of nonferrous metal smelting slag is arousing great attention in the field of treatment and disposal of solid waste. To deal with the aforementioned problems, a new treatment method of nonferrous metal smelting fuel gas is proposed for synchronous desulfurization and denitrification by using the slurry of nonferrous metal smelting slag with the addition of oxygen carrier to enhance the reaction efficiency. In this research project, copper smelting slag, lead and zinc smelting slag, and tin smelting slag are chosen as raw materials to prepare the catalyst for synchronous desulfurization and denitrification. The effects of composition and structure of nonferrous smelting slag on the catalytic capacity of the prepared catalyst are to be studied. The preparation condition of the catalyst is optimized. The mass-transfer mechanism between fuel gases (sulfur dioxide, nitrogen oxide) and slurry of nonferrous metal smelting slag in the multiphase system is investigated. The mechanism of catalytic oxidation of sulfur dioxide and nitrogen oxide by using slurry of nonferrous metal smelting slag is also discussed. To sum up, a new catalytic wet oxidation method of synchronous desulfurization and denitrification can be presented for treatment of nonferrous metal smelting fuel gases.

有色金属冶炼烟气是治理难度最大的工业废气之一，烟气中SO2和NOx污染物排放已经难以经济有效地满足日趋严格的环保要求。有色金属冶炼渣是典型的大宗工业固体废物，对环境危害大，其综合利用是固体废物处理处置的难点之一。针对以上问题，本项目提出利用有色金属冶炼渣浆液脱除有色金属冶炼烟气中SO2和NOx，并通过添加氧传递剂强化反应途径。具体研究内容如下：选取铜、铅锌、锡等有色金属冶炼渣，开展冶炼渣矿物组成结构与脱硫硝性能间的构-效关系、冶炼渣脱硫脱硝浆液的制备与优化、SO2、NOx与冶炼渣浆液间的多相传质机理及强化途径、冶炼渣液相催化氧化脱硫脱硝机理研究，通过上述研究，建立一种湿式同步脱硫脱硝的方法，达到资源化方式处理废气的目的。

本基金针对有色金属冶炼渣处理处置难的问题以及有色冶炼行业缺乏适合的脱硫脱硝技术，提出采用有色金属冶炼渣替代传统石灰石/石膏等传统湿法吸收剂耦合氧传递剂同步脱硫脱硝，该技术成本低廉，吸收效率较高、有效利用了工业固废、达到了“以废治废”的目的。项目通过筛选不同种类的有色金属冶炼渣，优选出铜冶炼渣及锰渣作为合适的吸收剂，并耦合高锰酸钾和黄磷作为氧传递剂。铜转炉渣/黄磷复合浆液具有良好的脱硫脱硝效率，高效的脱硫脱硝能力主要归因于于铜渣中二价铁离子、铜离子浸出所获得的液相催化氧化能力，降低了SO2转变为硫酸的活化能，进一步提升SO2吸收能力。由于黄磷易燃的问题，造成了其技术工业应用困难。因此后面采用了高锰酸钾作为优选的氧化剂，在原始铜渣和锰渣基础上对其物相结构和化学组成进行分析，其结果表明，铜/锰渣中其含有的还原性物相（如，磁铁矿，冰铜，硫化锰等）与高锰酸钾优先反应，抑制了有效的脱硝，因此进一步提出了钙基热改性铜渣/高锰酸钾、钙基热改性锰渣/高锰酸钾复合浆液同步脱硫脱硝技术。通过热改性预处理技术有效转变铜/锰渣物相结构，降低还原性物相含量，提升其有效活性组分。并针对锰渣中的α-MnO2作为有效的活性组分进行了密度泛函计算，通过计算吸附能以及反应路径，结合实验结果进行了深入的反应机理研究。