Browsing by Author "Aaltonen, Miamari"
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- Characterization of adherent anode slimes in copper electrorefining
Kemian tekniikan korkeakoulu | Master's thesis(2014-12-02) Aaltonen, MiamariThe goals of the thesis were to produce information of the adherent anode slimes and to examine the effects that anode composition and process parameters have on them. In the experimental section, 31 adherent anode slime samples were examined with the help of moisture content determination, settling tests, particle size distribution measurements, chemical analysis, x-ray diffraction and scanning electron microscopy. Corresponding anode lug samples were examined with the help of chemical analysis and optical microscopy. From the produced analysis data, correlations were difficult to establish. A connection was found between the chemical and XRD analysis results of nickel, which is also in line with the information found in literature. The process parameter data was not compared with the analysis results due to difficulties in connecting the sample with the corresponding data. Based on the analysis results, adherent anode slime sampling and some of the experimental methods need to be developed further. Also, information can still be extracted from the data produced with the help of more advanced data analysis. - DEVELOPMENT OF CHARACTERIZATION METHODS FOR ADHERENT ANODE SLIMES IN COPPER ELECTROREFINING
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2016) Kiviluoma, Mikko; Aaltonen, Miamari; Aromaa, Jari; Lundström, Mari; Forsen, OlofAdherent anode slimes can cause anode passivation in copper electrorefining and lower the efficiency of copper electrorefining. Declining concentrate grades cause larger impurity levels in anodes, thus creating larger quantities of slimes in the refining process. In order to investigate the characterization methods for adherent anode slimes in copper electrorefining, experiments were conducted for the Boliden Harjavalta Pori refinery material. Methods such as particle size determination, chemical (ICP) analysis, settling rate determination, XRD, SEM-SE, SEM-BSE and SEM-EDS were applied. In addition, adherent anode slime samples were compared to optical micrograph and SEM-BSE images of respective anode copper samples. It was shown that SEM-EDS and SEM-BSE provided precise information about phases formed during electrorefining. The settling rate and particle size had a correlation only with a copper content of anode slime. The main phases in the anode slime were copper and lead sulphates as well as copper-silver selenides. NiO was shown to be the major Ni-bearing phase in the adherent slime. Nickel, tellurium and lead had the strongest, whereas arsenic, selenium and antimony had the weakest tendency to report to the anode slime. - Leaching of Metals from Spent Lithium-Ion Batteries
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2017-10-31) Aaltonen, Miamari; Peng, Chao; Wilson, Benjamin; Lundström, MariThe recycling of valuable metals from spent lithium-ion batteries (LIBs) is becoming increasingly important due to the depletion of natural resources and potential pollution from the spent batteries. In this work, different types of acids (2 M citric (C6H8O7), 1 M oxalic (C2H2O4), 2 M sulfuric (H2SO4), 4 M hydrochloric (HCl), and 1 M nitric (HNO3) acid)) and reducing agents (hydrogen peroxide (H2O2), glucose (C6H12O6) and ascorbic acid (C6H8O6)) were selected for investigating the recovery of valuable metals from waste LIBs. The crushed and sieved material contained on average 23% (w/w) cobalt, 3% (w/w) lithium, and 1–5% (w/w) nickel, copper, manganese, aluminum, and iron. Results indicated that mineral acids (4 M HCl and 2 M H2SO4 with 1% (v/v) H2O2) produced generally higher yields compared with organic acids, with a nearly complete dissolution of lithium, cobalt, and nickel at 25 °C with a slurry density of 5% (w/v). Further leaching experiments carried out with H2SO4 media and different reducing agents with a slurry density of 10% (w/v) show that nearly all of the cobalt and lithium can be leached out in sulfuric acid (2 M) when using C6H8O6 as a reducing agent (10% g/gscraps) at 80 °C. - Mechanical and hydrometallurgical processes in HCl media for the recycling of valuable metals from Li-ion battery waste
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2019-03-01) Porvali, Antti; Aaltonen, Miamari; Ojanen, Severi; Velazquez Martinez, Omar; Eronen, Emmi; Liu, Fupeng; Wilson, Benjamin P.; Serna Guerrero, Rodrigo; Lundström, MariThe present work offers a study on the engineering implications of the recovery of valuable fractions from industrially collected lithium battery (LIB) waste by mechanical and hydrometallurgical processes in HCl media. Direct leaching of LIB waste provides a possibility for Li extraction, a component that is lost into the slag fraction in the state-of-art high temperature processes. The challenges arising from the heterogeneous composition of industrial battery waste are highlighted, and the behavior of main metals present such as Co, Cu, Li, Mn, Ni and Al is observed. It is shown that mechanical separation processes can form fractions rich on Cu and Al, although subsequent refining stages are necessary. Regarding direct leaching, fast kinetics were found, as complete Li dissolution can be achieved in ca. 120 min. Furthermore, high solid/liquid ratio (>1/10) is required to increase metal value concentrations, resulting in a viscous slurry due to the graphite, plastics and other undissolved materials, which challenges filtration and washing of leach residue. Neutralization of the product liquid solution (PLS) result in co-precipitation of valuable battery metals along with Fe and Al. The highest value of LIBs lies in Co, subjected for solvent extraction (SX) or direct precipitation to make an intermediate product. SX can provide selectivity whereas Na 2 CO 3 precipitation provides a fast route for Co-Ni bulk production. Li 2 CO 3 precipitation from the remaining PLS is possible as zabuyelite - however, due to heterogeneity of the battery waste, the recovery of Li 2 CO 3 with battery-grade purity remains a difficult task to be achieved by direct precipitation route. - Platinaryhmän metalleja sisältävien sekundääriraaka-aineiden kartoitus
Kemian tekniikan korkeakoulu | Bachelor's thesis(2011) Aaltonen, Miamari - Recovery of lithium from lithium-ion battery waste
Kemian tekniikan korkeakoulu | Master's thesis(2017-06-13) Eronen, EmmiRecovery of lithium from spent lithium-ion batteries has recently been of interest due to increasing demand of portable electronics, electric vehicles and energy storage systems. Currently few industrial processes recover cobalt, nickel and lithium from battery waste using hydrometallurgical methods. However, future waste batteries will challenge the present processes due to more complex technology and decreasing amount of metals to be recovered. Leaching of spent Li-ion batteries have been studied using strong mineral acids such as sulfuric, hydrochloric and nitric acid. In comparing experiments hydrochloric acid has performed best. Also, organic acids can be used as leaching reagents. Solvent extraction and ion exchange can be used to selectively concentrate metals containing solution whereas chemical precipitation, electrowinning and/or cementation methods are used for the recovery of metals from spent Li-ion batteries. Impurities are often precipitated from the leach liquor by neutralization with NaOH solution. Cobalt, nickel and lithium can be separated from complex metal containing solution by solvent extraction using different extractants such as Cyanex 272 or P507. In this work precipitation and solvent extraction were investigated to recover mainly cobalt, nickel and lithium from leach liquor. Temperature (30, 40 and 50 °C) and pH (5.0, 5.5 and 6.0) dependency were studied in the purification step of leach liquor. Iron, aluminum and copper were precipitated together using 2 M sodium hydroxide solution at 50 °C when equilibrium pH was 5. Temperature (30, 40 and 50 °C) and pH dependency were studied in the precipitation of cobalt, manganese and nickel as hydroxides (pH 7.5, 8.0 and 8.5) and carbonates (pH 7.0, 7.5 and 8.0). Cobalt, manganese and nickel were precipitated in one stage using 2 M sodium carbonate solution at 50 °C when equilibrium pH was 8. Lithium was precipitated successfully by adding stoichiometric amount of saturated sodium carbonate solution at 50 °C. Before lithium recovery the liquor was evaporated in order to increase the concentration of lithium. Lithium carbonate recovery efficiency was 59 % and calculated estimation of the purity 95%. Solvent extraction has been studied widely in the separation of cobalt and nickel. In this work, the separation of cobalt and manganese from nickel and lithium was performed with 40% saponified Cyanex 272. Optimal parameters were 2:1 organic-to-aqueous ratio, contact time 15 min, equilibrium pH 5.3 and temperature 30 °C. 98% of cobalt and 99% of manganese were separated from nickel and lithium in one extraction stage. Cobalt and manganese were stripped in single stage with 2 M H2SO4 and the efficiencies were 96% and 93%, respectively. Scrubbing before stripping was recommended for future experiments. Conceptual flowchart for the recovery of metals was suggested according to results and literature.