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In this work, the feasible of the recovery of nickel from stainless steelmaking sludge by circular leaching and extraction was investigated. The contents of main elements in the sludge were analyzed first. In the circular leaching process, the valuable metal in the sludge was proved to be leached selectively through controlling the pH of leached solution. When the pH of leached solution was 4.93, the leaching rate of Ni was 19.2%, but Fe and Cr were undetected in the leached solution. Then, trough circular leaching, the solution with high content of Ni and low contents of other metals was obtained. Fe and Cr were accumulated in the leached residue. In the extraction process, Versatic 10 and M84 were used as extractants to treat the leached solution. The extraction rate of Ni was over 80% when the equilibrium pH was 3.5, while the extraction rates of other metals were all below 10%. In this study, Ni was proved to be separable recovery by circular leaching and extracting from the leaching solution. [ABSTRACT FROM AUTHOR]