Yang Dongfang, Yang Qingyuan, Ma Wenhui, Wang Shiding, Lei Yun
Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China; National Engineering Research Center for Vacuum Metallurgy, Kunming 650093, China.
Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China; National Engineering Research Center for Vacuum Metallurgy, Kunming 650093, China.
Waste Manag. 2023 Sep 5;171:237-247. doi: 10.1016/j.wasman.2023.08.035.
Spent automotive catalysts (SACs) and diamond-wire-saw silicon kerf (DWSSK) are classified as hazardous wastes. Currently, the two wastes are treated separately using unrelated approaches. More than two independent approaches are required to recover platinum group metals (PGMs), Zr and rare earth elements (REEs) from SACs, and recover Si from DWSSK, which is time-consuming and laborious. In this study, a new approach was proposed to co-treat the two wastes based on the concept of using waste treats waste: using DWSSK (∼89.85 wt% Si) as a new metal collector to extract PGMs, REEs, and Zr simultaneously from SACs to obtain a Si-VM alloy (VM: valuable metal); meanwhile, using the carrier of SACs to form molten slag to eliminate the main impurity, O, from DWSSK. The largest recovery ratios of Pd, Rh, Zr, Ce, La, and Nd from SACs were 99.50 ± 0.10%, 99.14 ± 0.14 %, 96.19 ± 0.76%, 67.18 ± 4.57%, 61.24 ± 4.93% and 47.65 ± 7.27%, respectively, and the largest removal ratio of O from DWSSK was 99.96%. After smelting, the Si-VM alloy was separated into high-purity Si and VM-containing acid solutions via acid leaching. The leaching ratios of Pd, Rh, Ce, La, Nd, and Zr were 99.78%, 98.15%, 99.93%, ∼100%, 99.76% and 99.98%, respectively. The purity of Si was upgraded from 89.85 wt% (in DWSSK) to 99.98 wt% after acid leaching. The new approach proposed in this study is considered more environmentally friendly and cost-effective than the regular approaches that treat the two wastes separately.
废旧汽车催化剂（SACs）和金刚石线锯硅粉（DWSSK）被归类为危险废物。目前，这两种废物采用不相关的方法分别处理。从SACs中回收铂族金属（PGMs）、Zr和稀土元素（REEs），以及从DWSSK中回收Si，需要两种以上独立的方法，既耗时又费力。在本研究中，基于以废治废的理念，提出了一种协同处理这两种废物的新方法：利用DWSSK（约89.85 wt% Si）作为一种新型金属捕集剂，同时从SACs中提取PGMs、REEs和Zr，以获得一种Si-VM合金（VM：有价金属）；同时，利用SACs的载体形成熔渣，去除DWSSK中的主要杂质O。从SACs中回收Pd、Rh、Zr、Ce、La和Nd的最大回收率分别为99.50±0.10%、99.14±0.14%、96.19±0.76%、67.18±4.57%、61.24±4.93%和47.65±7.27%，从DWSSK中去除O的最大去除率为99.96%。熔炼后，通过酸浸将Si-VM合金分离为高纯Si和含VM的酸溶液。Pd、Rh、Ce、La、Nd和Zr的浸出率分别为99.78%、98.15%、99.93%、~100%、99.76%和99.98%。酸浸后，Si的纯度从DWSSK中的89.85 wt%提高到99.98 wt%。本研究提出的新方法被认为比分别处理这两种废物的常规方法更环保、更具成本效益。
Zotero 插件