TY - JOUR
T1 - Evaluation of two-step processes for the selective recovery of Mn from a rich Mn residue
AU - Sadeghi, S. Maryam
AU - Ferreira, Carlos M.H.
AU - Soares, Helena M.V.M.
N1 - Funding Information:
This work was performed in the framework of the financing with reference LAQV (UID/QUI/50006/2013 – POCI/01/0145/FEDER/007265) with financial support from FCT/MEC through national funds and co-financed by FEDER, under the Partnership Agreement PT2020. S. Maryam Sadeghi would like to thank the support from her grant with reference SFRH/BD/95540/2013 from FCT.
Funding Information:
This work was performed in the framework of the financing with reference LAQV (UID/QUI/50006/2013 – POCI/01/0145/FEDER/007265) with financial support from FCT/MEC through national funds and co-financed by FEDER , under the Partnership Agreement PT2020. S. Maryam Sadeghi would like to thank the support from her grant with reference SFRH/BD/95540/2013 from FCT .
Publisher Copyright:
© 2018
PY - 2019/1
Y1 - 2019/1
N2 - 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.
AB - 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.
KW - Circular economy
KW - Manganese
KW - Microwave
KW - Oxidative precipitation
KW - Recycling
KW - Reductive leaching
KW - Solvent extraction
KW - Ultrasound
KW - Zinc
UR - http://www.scopus.com/inward/record.url?scp=85055540628&partnerID=8YFLogxK
U2 - 10.1016/j.mineng.2018.10.014
DO - 10.1016/j.mineng.2018.10.014
M3 - Article
AN - SCOPUS:85055540628
SN - 0892-6875
VL - 130
SP - 148
EP - 155
JO - Minerals Engineering
JF - Minerals Engineering
ER -