Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Mercury Removal from Glycine Leach Solutions Using Sodium Sulfide (Na2S) Precipitation
Kantarci, Sadiye; Alp, Ibrahim; Youpoungam, Abdou Azizi; Sivircik, Salih
Amino acid leaching has been considered an environmentally friendly alternative for gold recovery; however, the dissolution of mercury (Hg) during the leaching of amalgamation tailings remains a major challenge. This study is a novelty study that focuses on Hg removal by passing the Hg-containing tailings, previously processed by amalgamation, into solution via glycine (NH(2)CH2COOH) leaching. In this regard, a precipitation method using sodium sulfide (Na2S) was developed to remove Hg from solutions obtained after glycine leaching. The effects of precipitation time, pH, Na2S dosage, and temperature were investigated. The effects of pH, precipitation time, and temperature were found to be limited within the investigated ranges. The results showed that Na2S dosage was the most effective parameter in mercury removal. The initial Hg concentration of 12,160 ppb was reduced to 223 ppb at a Na2S:Hg molar ratio of 60, corresponding to approximately 98% removal efficiency under the selected operating conditions. Increasing the Na2S:Hg ratio to 80 resulted in a slightly higher removal efficiency (similar to 99%) with a final Hg concentration of 144 ppb; however, a ratio of 60 was considered optimal in terms of reagent consumption and process efficiency. The outcomes indicate that Hg removal with Na2S is a rapid and effective process under alkaline conditions, while Au remains in solution and Cu and Ag are partially removed, indicating limited selectivity and the need for further optimization. Therefore, this study provides a basis for developing more environmentally friendly processes for amalgamation tailings.
- MakaleAçık Erişim2025Sulfur Removal From Low-Grade Turkish Kaolin Clay
Erkan, Ilker; Alp, Ibrahim
This study investigated the effects of NaOH direct leaching for sulfur removal from a kaolin ore from the Balıkesir region, Turkey. Characterization studies were undertaken before sulfur removal studies to enlighten the structure and originate the source of sulfur. The characterization studies revealed that the ore was mainly composed of quartz, with sulfur originating from alunite minerals with opal inclusions. The leaching process was tested under varying NaOH concentrations (1.5–2 M), temperatures (95 ± 2°C), and durations (2 h) in temperature-controlled closed systems to maintain consistency. Results demonstrated complete (100%) sulfur removal from alunite under optimal conditions. However, significant mass losses (18.15%–45%) occurred because of the dissolution of kaolinite along with alunite, indicating the method's effectiveness in sulfur removal but also its potential drawbacks for kaolinite retention.
- MakaleAçık Erişim2024Exploring the utilization potential of kaolin in the Balıkesir Sındırgı region
Alp, Ibrahim; Erkan, Ilker
Natural kaolins may contain some metal cations (K+, Na+, Mg+2, Ca+2) and anions such as carbonate, phosphate, and sulfate as impurities, depending on the formation conditions. The kaolins of Turkiye generally give a high-quality white color after firing due to their low Fe2O3 content. Unfortunately, Turkiye’s kaolin deposits generally contain high levels of SO3. Since the alunite mineral, which is the source of SO3, cannot be removed from the structure by known methods, kaolins containing alunite can only be used in the white cement sector. In this study, the suitability of the kaolins of the Balıkesir Sındırgı region, which has a large part of the kaolin reserves of Turkiye, to the areas of use where kaolin is mostly used in its current state has been investigated, and the samples obtained from the region have been examined in which areas of use they are suitable for use in raw form, and suggestions have been made about the enrichment methods to be carried out by comparing with the studies in the literature.