Evaluation of two-step processes for the selective recovery of Mn from a rich Mn residue

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Siamak Maryam Sadeghi (Author) Other; Carlos M. H. Ferreira (Author) Other; Helena M. V. M. Soares (Author) FEUP

Journal

Title: Minerals Engineering

Vol. 130

Pages: 148-155

ISSN: 0892-6875

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 8 Citations

INSPEC

Other information

Authenticus ID: P-00P-TZS

DOI: 10.1016/j.mineng.2018.10.014

Abstract (EN): In this work, effective two-step processes for recovering manganese (Mn), as well as zinc (Zn), from a rich Mn residue, that mainly consists of Mn and carbon with lesser amounts of Zn and Fe, are proposed. First, three different methods (conventional, ultrasound- and microwave-assisted) were evaluated for reductive acid leaching of the residue. Subsequently, two different strategies for purification of Mn from the leachate were considered: oxidative precipitation of Mn with persulfate and solvent extraction with Cyanex 302 as the extractant. The results showed that microwave-assisted leaching was the most effective in terms of the percentage of metal leached (with 98 and 100% of Mn and Zn, respectively) as well as the effectiveness of time and reagent consumption. Both Mn purification strategies were effective; with the oxidative precipitation, a 99.7% pure MnO2 precipitate and 3.30 g/L Zn solution with a purity of 99.9% were obtained at a global yield of 97.4 and 94.8%, respectively. Solvent extraction resulted in a 32.6 g/L Mn solution with a purity of 99.9% and 35.2 g/L Zn solution with a purity of 98.4%, with global yields of 96.3 and 100%, respectively. Based on these results, a sequential two-step procedure for recovering all valuable products (Mn, Zn and graphite) with high efficiency from a Mn rich residue is proposed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8