Scientific Mining Journal

Scientific Mining Journal

Volume 58 - No 4 (December 2019)
CONCENTRATION OF VALUABLE METALS FROM PRINTED CIRCUIT BOARDS USING MINERAL PROCESSING METHODS
DOI 10.30797/madencilik.666380 Esra Tanısalı, Mustafa Özer, Fırat Burat
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With the developing technology in recent years, the variety and production of electronic products has increased rapidly. The amount of unused products increases with high consumption rate, these products are disposed as scrap. These types of scrap, called electronic waste, cause serious damage to the environment and livings due to the harmful elements and components. Apart from harmful compounds, the high content of precious metals in e-waste compared to the natural sources makes them very attractive for metal recovery. Print circuit boards (PCB’s), which comprise 3% of the e-wastes, attract attention with high Cu, Au and Ag contents. Within the scope of this study, comminution and classification processes were applied and then shaking table was subjected to -2 , + 0.5 and -0.5 mm fractions to recover Cu, Au, Ag from PCB’s. As a result of the enrichment tests, 62% wt. of the feed was obtained with 88.2% Au, 95.3% Cu and 93.6% Ag recoveries.
THE USE OF DIFFERENT BREAKAGE TEST PROTOCOLS IN MULTICOMPARTMENT BALL MILL MODELLING
DOI 10.30797/madencilik.666393 Deniz Altun, Okay Altun
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Modelling of grinding circuits is crucial for circuit design and optimization. Determination of breakage distribution function of the materials is important for accurate and reliable modelling. In this study, the model structure was focused on using separate breakage tests for each chamber. Within the study, sampling studies were performed around the grinding circuit containing 2-chamber ball mill and inside the mill and, particle size distributions of collected samples were determined. Then mass balance studies were performed. Single particle drop weight test for the chamber-1 while Hardgrove test for the second chamber of the mill was carried out then size-dependent breakage distribution functions were calculated. The study is the first application of using Hardgrove technique in the ball mill model. Each chamber was modelled separately by using Perfect Mixing Model. Simulation results showed that the product estimations were accurate for the chamber-1 that the Hardgrove test was suitable for the chamber-2.
EFFECT OF MILL FEED SIZE DISTRIBUTION AND GRINDING MEDIA SIZE ON SIZE REDUCTION PERFORMANCE OF AN INDUSTRIAL SCALE VIBRATING BALL MILL (VBM) IN CEMENT CLINKER GRINDING
DOI 10.30797/madencilik.666403 Ömürden Genç, Ahmet Hakan Benzer
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In this study, open circuit single and two stage industrial scale vibrating ball mill (VBM) grinding performance of raw (uncrushed) cement clinker was investigated using different mill feed size distributions and grinding ball size configurations. The mill was modelled for the test cases using perfect mixing mathematical modelling approach. Different ball size configurations were applied in the grinding tests to estimate the effect of ball size configuration on grinding performance. Proposed coarse ball size configuration (30-20-15mm) was determined to increase the size reduction performance of single stage VBM grinding when coarse mill feed material was fed to the VBM (F50=185μm) as compared to the finer mill feed case (F50=24μm). VBM grinding performance was determined to increase with finer mill feed material (F50=24μm) and application of finer ball size configuration (10-8-6mm) in single stage grinding case as compared to the two stage grinding case.
RECOVERY OF ZINC AND MANGANESE FROM WASTE ALKALINE BATTERY POWDER BY TWO-STAGE LEACHING PROCESS
DOI 10.30797/madencilik.666410 Gülistan Deniz Turhan Özdemir, Nizamettin Demirkıran
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In this work, the selective dissolution of zinc and manganese in the waste alkaline battery powders was investigated by applying two-stage leaching method. In the first-stage of leaching, zinc in the battery powder was dissolved using NaOH solutions. The solid residue containing manganese was separated from the solution by filtration and used in the second leaching step. Sulfuric acid solutions containing molasses was used as leaching agent in the second-stage leaching treatment. In each leaching step, the effects of solution concentration, temperature, stirring speed and solid to liquid ratio on the dissolution of zinc and manganese were examined. The findings obtained showed that the experimental parameters had a significant effect on the dissolution of zinc and manganese. It was observed that the dissolution efficiency for both metal increased with an increase in the solution concentration, temperature and stirring speed, and with a decrease in the solid to liquid ratio. At the experimental conditions of a sodium hydroxide concentration of 1.5 mol/L, a reaction temperature of 40 °C, a solid to liquid ratio of 2/500 g/mL, a stirring speed of 500 rpm, and a reaction time of 120 min., it was determined that 77% of zinc in waste battery powder was dissolved. While concentration of sulfuric acid, temperature, solid to liquid ratio, stirring speed, and reaction time were 1.5 mol/L, 50 °C, 2/500 g/mL, 500 rpm, and 120 min. respectively, it was found that 85% of manganese in the leach residue was dissolved.
MINERALOGICAL CAHARACTERIZATION OF KARAÇAM LATERITIC NICKEL ORE AND DETERMINATION OF ITS PHYSICAL BENEFICIATION DEPORTMENT
DOI 10.30797/madencilik.666432 Özgür Özcan, N. Metin Can, İlkay B. Can, Sönmez Sayılı
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In this study, the detailed mineralogy and beneficiation possibilities of a lateritic nickel ore from Mihalıççık-Eskişehir region was investigated. Quantitative mineralogical analysis of the ore was performed using MLA (Mineral Liberation Analyzer); ernienickelite and pimellite minerals were determined as nickel bearing minerals. Heavy liquid test was performed to determine the amenability of the ore to gravity separation. In the scope of beneficiation studies, optical sorting, dry and wet magnetic separation and microwave heating were applied. As a result of the tests, there was no significant improvement in nickel grade. Only a slight decrease in the arsenic grade of the microwave-heated ore was observed. The presence of ernienickelite locked with very fine silicates (usually clays and Si oxides), supports the fact that the ore cannot be beneficiated easily by physical beneficiation methods.
AN ANALYSIS AND COUNTERMEASURES OF FATAL ACCIDENTS CAUSED BY FIREDAMP EXPLOSIONS IN UNDERGROUND COAL MINES IN TURKEY
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Fatal accidents in underground coal mines in Turkey are common and experienced frequently. The major accident categories for underground coal mining in Turkey are gas related accidents (firedamp and outbursts), roof falls, flooding, fire and transport. In recent years, coal mine gas related accidents in Turkey, which are usually caused by firedamp and outbursts, are still threatening miners’ lives. Firedamp explosions are majorly serious mine accidents that can occur quickly and cause great deal damage. In this study, work-related accidents caused by firedamp and another gas accidents in Turkey between the years 2010-2016 were analyzed. As a result of these analyses, the number of deaths in underground coal mines in the past 7 years is 550 and the fatality rate is found to be 96.86%. The percentage of gases as the cause of the deaths is 70.18%. In this study, countermeasures are proposed that can prevent and control firedamp explosions and other gas related accidents.