湿法炼锌渣还原造锍混合熔炼应用基础研究

In order to solve the problems, such as difficult disposition, inferior utilization of ferrous resources in the current process of zinc hydrometallurgical slag, this work proposes reducing and matting smelting process to dispose jarosite slag, goethite slag and lead and sliver bearing slag, which are generated in zinc smeltry in inner mongolia. Valuable metals, including lead, indium, gold and silver, were recycled high efficient,and zinc, arsenic, cadmium and sulfur were collected in slag and iron matte at the same time. Based on this, we intend to scientific determine the reaction courses and mechanism of the reducing-matting co-smelting, the three-phase equilibrium mechanism among the metal-matte-slag, reaction behaviors and distribution discipline of the associated elements. Then, we set up the basic theory system of the reducing-matting co-smelting process of the zinc hydrometallurgical slag. Based on this, the applied technical prototype was built by the condition optimizing of the new process. Lastly, this work can explore a solution program for the multicomponent and unwieldiness lead-iron bearing solid-wastes, generated in non-ferrous smelting industry in our country, to realize comprehensive utilization and harmless disposition of resources, which is technical feasibility, economy reasonable, security, environmental protection and accorded with national conditions.

针对当前湿法炼锌渣综合处置难、铁资源没有得到有效利用等问题，本课题以内蒙古地区锌冶炼企业产出的铁矾渣、针铁矿渣、铅银渣等湿法炼锌渣为研究对象，提出还原造锍混合熔炼新工艺，在高效回收铅、铟、金、银等有价金属的同时，使锌、砷、镉、硫等元素分别在炉渣和铁锍中得到定向富集。通过系统研究还原造锍混合熔炼反应历程和机理、“炉渣/铁锍/金属铅”三相平衡机制以及伴生元素反应行为和分配规律，建立湿法炼锌渣还原造锍混合熔炼清洁冶金基础理论体系，在此基础上通过工艺条件优化建立应用技术原型，最终为我国有色冶炼行业中多组元难处理含铅铁复杂固废的资源综合利用和无害化处置探索一条技术可行、经济合理、安全环保、符合国情的解决方案。

针对当前湿法炼锌渣综合处置难、铁资源没有得到有效利用等问题，本课题以内蒙古地区锌冶炼企业产出的铁矾渣、针铁矿渣、铅银渣等湿法炼锌渣为研究对象，提出还原造锍混合熔炼新工艺，在高效回收铅、铟、金、银等有价金属的同时，使锌、砷、镉、硫等元素分别在炉渣和铁锍中得到定向富集。系统研究还原造锍混合熔炼反应热力学、历程和机理、反应过程界面行为、PbSO4分解动力学、“炉渣/铁锍/金属铅”三相平衡机制以及伴生元素反应行为和分配规律，建立湿法炼锌渣还原造锍混合熔炼清洁冶金基础理论体系，在此基础上通过工艺条件优化建立应用技术原型。.主要结论如下：（1）计算分析了锌冶炼渣的还原造锍熔炼过程的热力学可行性，结果证实含铁物相中NaFe3(SO4)2(OH)6极易发生还原反应，FeOOH极易进行分解反应；铅的硫化物、氧化物和硫酸盐的间接还原反应均可自发地向正向进行，并随着温度的升高，发生相应反应的趋势变大。（2）还原气氛和反应温度是决定PbSO4物相还原造锍反应的主要影响因素，还原气氛能够使PbSO4选择性还原为PbS，使PbSO4中的元素硫保留在PbS中，极大避免了SO2和SO3等含硫气体的生成。与此同时，还原气氛也会促进高温下PbS与Fe3O4的交互反应，实现PbS到PbO的转化和S在FeS中的固定；生成的PbO进而又被不断的还原为金属铅，遵循PbSO4—PbS—PbO—Pb反应历程。（3）经过一系列单因素工艺条件试验探索，得到了湿法炼锌渣还原造锍混合熔炼最佳工艺参数：熔炼温度1300 °C，保温时间150 min、还原剂配比10%、碳酸钠配比4%、预设炉渣渣型FeO/SiO2=1.4和CaO/SiO2=0.5。.通过以上系统研究，为我国有色冶炼行业中多组元难处理含铅铁复杂固废的资源综合利用和无害化处置探索了一条技术可行、经济合理、安全环保、符合国情的解决方案。