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Öğe An overview of halloysite mineral(Chamber of Mining Engineers of Turkey, 2023) Durgut, Emrah; Çınar, Mustafa; Özdemir, OrhanHalloysite is a type of clay mineral found in the kaolin group together with kaolinite, dickite, and nacrite minerals. Kaolinite is the most common mineral in this group, while dickite, nacrite, and halloysite are rarer. Although halloysite is primarily used in ceramic production, application in other industries is increasing and gaining economic value due to its unique properties. The use of halloysite is determined by the degree of purity and the properties of the nano-sized tubular structure. Naturally obtained halloysite mineral has a key position in the field of nanotechnology due to its unique physicochemical properties originating from its tubular structure. Also, due to its reserves in many parts of the world, halloysite is a more economical material for the sectors compared to artificially produced nanomaterials. And, they find many different application areas because of these features (morphological and physicochemical). Halloysite reserves known in Türkiye are located in the Çanakkale and Balıkesir regions. Although there are many useful studies on halloysite in different, additional studies are needed to understand the nano-sized properties of halloysite ore and to ensure its use that will provide maximum benefit. This study aimed to contribute to the studies on halloysite in terms of literature by compiling studies on the characterization of halloysite minerals, reserve information, physicochemical properties, enrichment methods, and usage areas.Öğe Digital image processing (DIP) application on the evaluation of iron-rich heavy mineral concentrates produced from river sand using a sequential mineral processing approach(Oficyna Wydawnicza Politechniki Wroclawskiej, 2021) Terzi, Mert; Kurşun Ünver, Ilgın; Çınar, Mustafa; Özdemir, OrhanIn this study, the iron-rich heavy mineral concentrate production from river sand as a byproduct of an alternative resource by gravity, magnetic separation, and flotation methods were investigated in detail. For the physical separation of the sample and increasing the Fe2O3 content, a shaking table and a wet high-intensity magnetic separator were used, respectively. The gravity and magnetic separation experiments included rougher, cleaner, and scavenger circuits. In the flotation experiments, cationic flotation with ethylenediamine under acidic conditions, and anionic flotation with sodium oleate under alkaline conditions were performed. The iron and silica content of the products obtained were determined by digital image processing (DIP) methods and compared with the classical analytical procedures. Finally, a flow chart was proposed for the processing of the ore according to the optimum enrichment parameters were determined from the experiments. The results obtained in this study show that it is possible to produce an iron-rich heavy mineral concentrate with Fe2O3 grade and recovery rate of 79.13% and 57.81%, respectively, in addition to a potential feed for the production of quartz sand and feldspar concentrates.Öğe Effect of blunging process on purification of halloysite ore from ferrous impurities by dry magnetic separation(Oficyna Wydawnicza Politechniki Wroclawskiej, 2024) Durgut, Emrah; Çınar, Mustafa; Boylu, Feridun; Özdemir, OrhanThe objective of this research is to study the effects of feed particle size, splitter angle, and washing process on Fe2O3 removal efficiency in the separation of ferrous impurities from halloysite ore by dry magnetic separation in order to increase the purity of halloysite sample after crushing and blunging processes separately. Firstly, after crushing ore in a jaw crusher and sizing to -2+1 mm, -1+0.5 mm, and -0.5+0.212 mm fractions, the sized materials were fed to REMS-type dry magnetic separator at a constant belt speed of 300 rpm with the splitter angles of 0, 15, 30 degrees separately. Maximum Fe2O3 removal efficiency (FRE) (97.1%) was obtained in the nonmagnetic product at -0.5+0.212 mm size fraction and 0 degrees splitter angle. The minimum Fe2O3 content (1.3%) was reached in the nonmagnetic product obtained in the experiment with the feed size of -2+1 mm and a splitter angle of 0 degrees. Secondly, dry magnetic separation was applied to the washed -2+0.212 mm size fraction after drying at room temperature to evaluate the coarse particle -sized halloysite ore that was gained by mechanical dispersion in the aqueous medium towards sodium hexametaphosphate (SHMP), while a significant part of the clay minerals went into fine size after the dispersion process. In the experiment performed with a 0 degrees splitter angle after washing, it was determined that halloysite concentrate of 0.4% Fe2O3 content could be obtained with 98.8% Fe2O3 removal efficiency. As a result of dry magnetic separation experiments, it was seen that Fe2O3 removal efficiency decreased as the splitter angle increased, while Fe2O3 content in magnetic and nonmagnetic products increased. It was determined that washing and cleaning of finesized minerals plastered on particle surfaces after mechanical dispersion and particle release of minerals with different magnetic properties increased the dry magnetic separation efficiency, and nonmagnetic products with very low Fe2O3 (0.4%) and high Al2O3 (31.9%) content was obtained. The blunging process in the presence of dispersant caused the dispersion of clay minerals and allowed to liberating of the ferrous minerals from the halloysite ore, hence the increase in the FRE for the magnetic separation.Öğe Fine-size separation of halloysite, kaolinite, and quartz minerals as binary systems using dispersion and sedimentation methods(Oficyna Wydawnicza Politechniki Wroclawskiej, 2025) Durgut, Emrah; Çavdar, Yunus Emre; Çınar, Mustafa; Yavuz, Osman; Özdemir, OrhanClay minerals are mainly composed of aluminum hydrosilicates. In some minerals, aluminum is completely or partially replaced by Fe or Mg. Alkaline minerals or alkali metals are present as major constituents of clay minerals. While some clay sources may contain a single clay mineral, they often contain different minerals such as quartz, calcite, feldspar, pyrite, etc. as impurities. They also contain organic matter and water-soluble salts. Halloysite is a clay mineral belonging to the kaolinite group and USA Environmental Protection Agency (EPA 4A) declared it as an innocuous/adaptable material to human health and the environment. Halloysite ore deposits are mainly found together with kaolinite and quartz minerals, but can also be found as a pure source. The degree of purity of halloysite ore determines the industrial area where it will be used and therefore its economic value. Since clay minerals are naturally composed of fine particles, it is necessary to disperse the clay particles in suspension to separate halloysite and kaolinite minerals. In addition, there are also fine-grained quartz minerals, and to recover pure halloysite minerals, it is necessary to determine their properties in the fine size fraction. In this study, the dispersion properties of halloysite, kaolinite, and quartz minerals in the presence of sodium silicate (SS), sodium tripolyphosphate (STPP), and sodium hexametaphosphate (SHMP) dispersants in fine-size fraction (-38 }m) were researched by particle size measurements and mineral separation properties were investigated by sedimentation experiments at different acidic, neutral, alkaline pH values. In dispersion experiments, the d90 values of halloysite, kaolinite, and quartz minerals were 74.0, 50.7, and 61.3 }m without any dispersant addition, and such values decreased to 54.7, 26.3, and 57.1 }m as SHMP increased to 10 kg/ton, respectively. d50 and d10 values showed a significant change for halloysite, while no important change was observed for kaolinite and halloysite. SHMP had the most effect on the particle size change in the dispersants especially on halloysite minerals. The least effect on particle size change was observed in the quartz sample with dispersant addition. The sedimentation experiments aimed to investigate the effects of pH on halloysite, kaolinite, and quartz recoveries in binary systems as settled products. Kaolinite settled more at acidic pH and halloysite at basic pH. There was no pH-dependent change in the settling behavior for halloysite and quartz. In the quartz-kaolinite system, quartz mineral settled more than kaolinite for all pH values. The settling experiments showed the importance of morphological differences between tubular halloysite and lamellar kaolinite minerals.
