Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Conference Object Citation - Scopus: 2Dissolution of Mixed Zinc-Carbon and Alkaline Battery Powders in Sulphuric Acid Using Ascorbic/Oxalic Acid as a Reductant(Minerals, Metals and Materials Society 184 Thorn Hill Road Warrendale PA 15086, 2012-03-17) Kaya, Muammer; Kursunoglu, SaitThe aim of this study was to investigate the effectiveness of ascorbic (C<inf>6</inf>H<inf>8</inf>O<inf>6</inf>) / oxalic (C<inf>2</inf>H <inf>2</inf>O<inf>4</inf>) acid as a reductant for the simultaneous recovery of zinc and manganese from a spent and mixed zinc-carbon and alkaline battery powder in sulphuric acid leaching. The effects of sulfuric acid concentration, ascorbic/oxalic acid dosages, reaction temperature and leaching time on the zinc and manganese dissolutions were investigated according to 2k full factorial experimental design; then, a simple optimization study was carried out for the best reductant. The optimum reductive acid leaching conditions were determined at 3 hours leaching time, 70°C leaching temperature, 0.5M sulfuric acid concentration, 13 g/L ascorbic acid dosage, 1/20 g/mL solid/liquid ratio and 200 rpm stirring speed. Under these conditions, the dissolution efficiencies were 99.9% for Zn and 99.3% for Mn. When our results were compared with the previous results, our findings were better than previous studies. In addition, the manganese dissolution kinetics was undertaken, and the activation energy was found to be 7.04 kJ/mol. Selective precipitations of Zn and Mn from acid solutions were carried out using NaOH and KOH. Using 3M NaOH as precipitating agent at room temperature and at pH 8; 95.4% of Zn and at pH 10; 93.7% of Mn were precipitated from the leaching solution. Under the same conditions, using 3 M KOH at pH 8; 91.6% of Zn and at pH 10, 96.4% of Mn were precipitated. Based on the experimental results obtained, an appropriate flow sheet was proposed to recover zinc and manganese. © 2020 Elsevier B.V., All rights reserved.Article Citation - Scopus: 2Kalsitik ve Dolomitik Kireçtaşlarının Çimentolu Macun Dolgunun Çevresel Davranışına Etkisi(Chamber of Mining Engineers of Turkey, 2022-03-07) Yılmaz, Tekin; Ercikdi, BayramTo enhance the strength and stability of cemented paste backfill (CPB), many alkaline materials are utilised as replacement or additive to binder or tailings in CPB. However, the effect of these materials on groundwater pollution of CPB needs to be comprehensively investigated. In this study, effects of the utilization of calcitic and dolomitic limestone (CL and DL) as replacement (10 wt.%) to sulphide mine tailings (S-MT) in CPB mixture on the long-term environmental behaviour of CPB were investigated. For this purpose, CPB samples (CPBs) were subjected to dynamic tank leaching tests over 360-days and the analyses of pH, sulphate (SO4 2-) and heavy metals (HMs) on the leachates were carried out. The effects of mineralogy and microstructure on the environmental behavior of CPBs were also examined by X-ray diffractometry and porosity tests. The findings showed that with the utilization of CL and DL, the pH of leachates remained at alkaline levels and the release of SO4 2- was significantly reduced. Furthermore, the denser microstructure in CPBs of CL and DL contributed to be prevented or be remarkably reduced the HMs-releases (except Cu, Mo and Pb). The results reveal that the mechanical properties of CPB as well as its impact on the groundwater pollution should be carefully evaluated. © 2022 Elsevier B.V., All rights reserved.