Tannery sludge (Ts) and chrome-tanned leather shavings (CTLs) are regarded as hazardous wastes, which are produced considerably in industrial activities. It is urgent to develop an efficient and cost-effective method to treat these hazardous wastes and simultaneously recover their useful components. In this study, thermodynamic calculation and thermogravimetric characterization were used for analyzing the theoretical feasibility of calcinating Ts and CTLs and the factors affecting recovery of Cr in calcination process were investigated. The results showed that calcination environment, including Na₂CO₃ content, temperature, calcination time and organic compounds in materials, could greatly affect the recovery of Cr (Ⅵ) from Ts and CTLs. Meanwhile, the glassy chromate phase which formed in the calcination process could interfere with Cr (Ⅵ) release, resulting in decrease of recovery Cr. Thus, to overcome the existing negative effect in calcination process, a segmented calcination with Na₂CO₃ as a “catalyst” was developed and identified as a low-cost and simple process to effectively recover Cr (Ⅵ) from Ts and CTLs. The recovery of Cr (Ⅵ) from the Ts and CTLs increased by 12% and 38%, respectively, and the recovery of Cr (Ⅵ) from the mixed material reached 60%.

制革污泥（Ts）和铬鞣革屑（CTL）被视为危险废物，在工业活动中大量产生。迫切需要开发一种有效且具有成本效益的方法来处理这些危险废物并同时回收其有用成分。本研究利用热力学计算和热重分析法分析了煅烧Ts和CTL的理论可行性，并研究了煅烧过程中影响Cr回收的因素。结果表明，煅烧环境包括Na ₂ CO ₃材料中的含量，温度，煅烧时间和有机化合物会极大地影响Ts和CTL中Cr（Ⅵ）的回收。同时，在煅烧过程中形成的玻璃态铬酸盐相可能会干扰Cr（Ⅵ）的释放，从而导致Cr的回收率降低。因此，为了克服在煅烧过程中存在的负面影响，开发了以Na ₂ CO ₃作为“催化剂”的分段煅烧，并将其确定为一种低成本，简单的方法，可以有效地从Ts和CTL中回收Cr（Ⅵ）。Ts和CTL中Cr（Ⅵ）的回收率分别提高了12％和38％，混合材料中Cr（Ⅵ）的回收率达到了60％。