Vierailija Paula Vehmaanperä

E-mail: Paula.Vehmaanpera@lut.fi
Mobile phone: +358 50 455 8412

Current Organisation
Separation Science (Superior organisation: LUT School of Engineering Science)

Research Interest
Dissolution of iron oxides has been extensively studied in single acid systems but studies with mixtures of acids are few. Kinetics and thermodynamics of dissolution of iron oxides are in general not agreed on. The objective here is to investigate the dissolution mechanisms of magnetite and hematite in acidic environments by adding oxalic acid in sulfuric or nitric acid. This can contribute to more efficient and environmentally friendly processes. The work is based on performing thermodynamic and kinetic experiments at different temperatures and acid ratios. So far the results have shown that the solubility of magnetite and hematite improves by adding oxalic acid in sulfuric acid. The temperature has an effect on the equilibrium kinetics, but higher temperatures do not automatically result in significantly higher solubility. The Kabai model has been found most suitable in describing the dissolution kinetics of magnetite and hematite in mixtures of oxalic and sulfuric acid. A solid specific constant a of the Kabai model has been found to vary for the different acid ratios for magnetite and hematite dissolution, which has not been reported by Kabai. The reason for the variation might indicate changes in the solid phase during the dissolution process.


Research Areas



Projects as Co-Investigator
Treatment and utilization of solid waste (01/01/2014 - 31/12/2015)
Funder: Tekes



Publications
Thermodynamic and Kinetic Studies of Dissolution of Hematite in Mixtures of Oxalic and Sulfuric Acid (2021)
Other
Vehmaanperä Paula, Salmimies Riina, Häkkinen Antti
Mining Engineering
Pressure filtration properties of sludge generated in the electrochemical treatment of mining waters (2020)
A1 Journal article (refereed), original research
Gafiullina Anastasia, Mamelkina Maria, Vehmaanperä Paula, et al.
Water Research
Thermodynamic and Kinetic Studies of Dissolution of Hematite in Mixtures of Oxalic and Sulfuric Acid (2020)
A1 Journal article (refereed), original research
Vehmaanperä Paula, Salmimies Riina, Häkkinen Antti
Mining, Metallurgy & Exploration
Improvement of the filtration characteristics of calcite slurry by hydrocyclone classification (2018)
A1 Journal article (refereed), original research
Vehmaanperä Paula, Safonov Dmitry, Kinnarinen Teemu, et al.
Minerals Engineering
Acidic dissolution of magnetite in mixtures of oxalic and sulfuric acid (2016)
A1 Journal article (refereed), original research
Salmimies Riina, Vehmaanperä Paula, Häkkinen Antti
Hydrometallurgy
Treatment and utilization of solid waste from the mining industry (2016)
B3 Unrefereed conference proceedings
Vehmaanperä Paula, Salmimies Riina, Miettinen Ville, et al.
Proceedings of the 16th Nordic Filtration Symposium
Removal of arsenic from water by adsorption (2013)
G2 Master’s thesis, polytechnic Master’s thesis
Vehmaanperä Paula




Last updated on 2021-02-03 at 04:03