铁捕集铂族金属的熔渣调控及其捕集机理的理论计算研究  

Slag Modulation and Trapping Mechanisms for the Recovery of Platinum Group Metals via Iron:A Theoretical Study

作　　者：杨泉 黄利南 李勇 江磊 吴喜龙[1] 赵雨 程显名 李孔斋 YANG Quan;HUANG Linan;LI Yong;JIANG Lei;WU Xilong;ZHAO Yu;CHENG Xianming;LI Kongzhai(Sino-Platinum Metals Resources(Yimen)CO.,Ltd.,Yuxi 651100,Yunnan,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction,Ministry of Education,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]贵研资源(易门)有限公司,云南玉溪651100 [2]昆明理工大学冶金与能源学院,云南昆明650093 [3]昆明理工大学教育部冶金节能减排工程研究中心,云南昆明650093

出　　处：《昆明理工大学学报（自然科学版）》2024年第2期1-12,共12页Journal of Kunming University of Science and Technology(Natural Science)

基　　金：云南省贵金属实验室科技项目(KKF020225236)。

摘　　要：以汽车废催化剂为原料的铂族金属(PGMs)再生利用不仅缓解供需矛盾,而且还能保障国家战略储备金属需求,具有重大战略意义.汽车废催化剂成分复杂,火法捕集PGMs的过程需要进行大量的实验以获得最佳的熔渣,从而提高PGMs的回收率.通过FactSage的理论计算对炉渣反应平衡模拟以达到优化炉渣的目的.FactSage计算结果表明,当添加剂CaO、SiO_(2)、Na_(2)CO_(3)和CaF_(2)的添加量分别占汽车废催化剂质量分数的40%、15%、30%和5%时,熔渣的性质最佳,即渣相的完全温度为1 330℃,粘度为1.92 Pa·s.本工作还结合DFT计算对铁捕集汽车废催化剂中PGMs的机理进行了研究.在超过1 390℃的高温条件下,Rh以取代掺杂的类型和δ-Fe形成合金结构.在912~1 390℃的温度区间内,Pd以取代掺杂的方式和γ-Fe形成合金,并只有在该温度区间才能形成Pd-Fe合金.此外,在该温度区间下,大部分Pt被捕集并以取代掺杂的方式和γ-Fe形成合金.当温度低于912℃时,Rh和Pt再次被α-Fe捕集并形成合金.然而,γ-Fe-Pd合金随着温度降低,形成的α-Fe-Pd的合金结构是不稳定的,这就导致Pd会从Fe相中析出,降低Pd的捕集率.总之,本研究为火法捕集PGMs提供了一种高效的炉渣优化方法.The recycling of platinum group metals(PGMs)from spent catalysts not only alleviates the contradiction between supply and demand,but also guarantees the demand for metals in the national strategic reserve,which is of great strategic significance.Automotive spent catalysts have complex compositions,and the process of capturing PGMs by pyrometallurgical methods requires a large number of experiments in order to obtain the optimal slag and thus improve the recovery of PGMs.In this work,the theoretical calculations of FactSage were used to simulate the slag reaction equilibrium for the purpose of slag optimization.The results of FactSage calculations showed that when the additives CaO,SiO_(2),Na_(2)CO_(3),and CaF_(2) were added at 40%,15%,30%,and 5%of the mass fraction of the spent catalyst,respectively,the slag properties were optimal,i.e.,the complete temperature of the slag phase was 1330℃,and the viscosity was 1.92 Pa·s.We also investigated the mechanism of iron trapping of PGMs in spent automobile catalysts in conjunction with DFT calculations.The results showed that Rh forms an alloy structure withδ-Fe in a substitution-doped type at high temperatures exceeding 1390℃;Pd can only form an alloy withγ-Fe in a substitution-doped manner in the temperature interval from 912℃to 1390℃;and most of the Pt is trapped and alloys withγ-Fe in a substitution-doped manner in this temperature interval.When the temperature is lower than 912℃,Rh and Pt are again trapped byα-Fe and form an alloy.However,γ-Fe-Pd alloys formα-Fe-Pd with decreasing temperature,and the alloy structure ofα-Fe-Pd is unstable,which leads to the precipitation of Pd from the Fe phase and reduces the recovery rate of Pd.In summary,the present study provides an efficient slag optimization method for the pyrometallurgy capture of PGMs.

关 键 词：汽车废催化剂 铂族金属回收 铁捕集 渣设计 机理研究 

分 类 号：TF833[冶金工程—有色金属冶金] X734.2[环境科学与工程—环境工程]