The Effect of Process Conditions on Sulfuric Acid Leaching of Manganese Sludge
Peer reviewed, Journal article
Published version
Permanent lenke
https://hdl.handle.net/11250/3102319Utgivelsesdato
2023Metadata
Vis full innførselSamlinger
- Institutt for materialteknologi [2549]
- Publikasjoner fra CRIStin - NTNU [38294]
Originalversjon
10.3390/ma16134591Sammendrag
Manganese sludge, an industrial waste product in the ferroalloy industry, contains various components and holds significant importance for sustainable development through its valorization. This study focuses on characterizing a manganese sludge and investigating its behavior during sulfuric acid leaching. The influence of process conditions, including temperature, acid concentration, liquid to solid ratio, and leaching duration, was examined. The results revealed that Mn, Zn, and K are the main leachable components, and their overall leaching rates increase with increasing temperature, liquid to solid ratio, and time. However, the acid concentration requires optimization. High leaching rates of 90% for Mn, 90% for Zn, and 100% for K were achieved. Moreover, it was found that Pb in the sludge is converted to sulfate during the leaching, which yields a sulfate concentrate rich in PbSO4. The leaching process for Mn and Zn species appears to follow a second or third order reaction, and the calculation of rate constants indicated that Mn leaching kinetics are two to five times higher than those for Zn. Thermodynamic calculations were employed to evaluate the main chemical reactions occurring during leaching.