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Wyszukujesz frazę "zinc oxide" wg kryterium: Temat


Wyświetlanie 1-9 z 9
Tytuł:
Leaching of zinc from low grade oxide ore using organic acid
Autorzy:
Irannajad, M.
Meshkini, M.
Azadmehr, A. R.
Powiązania:
https://bibliotekanauki.pl/articles/110892.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
leaching
zinc oxide ore
citric acid
smithsonite
Opis:
The leaching of low grade zinc oxide mining tailings by organic acid as a leaching agent was investigated. Zinc was extracted successfully from sample by citric acid leaching. The effects of solid-to- liquid ratio, acid concentration, reaction time, temperature and ore particle size on the leaching efficiency were studied. The results obtained showed that particle sizes and reaction time had not any significant effect on the leaching recovery of zinc from smithsonite in the sizes range of 40-350 μm. Under conditions: temperature of 80ºC, reaction time of 60 min, citric acid concentration of 0.5 mol/L, and solid to liquid ratio of 1:10, 82% of zinc could be recovered.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 547-555
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of polysorbate 80 on the flotation of zinc oxide ores with amines
Autorzy:
Xie, Qiaoling
Wang, Dandan
Han, Zhichao
Tao, Huchun
Liu, Sitong
Powiązania:
https://bibliotekanauki.pl/articles/2146852.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
polysorbate 80
pretreated amines
zinc oxide
flotation
Opis:
In this study, the influence of polysorbate 80 on zinc oxide flotation was investigated with an amine collector. The results indicated that the pretreatment of amines with polysorbate 80 enhanced the Zn grade and recovery obtained using zinc oxide flotation. Desliming prior to flotation is not suggested based on the results of this study. The appropriate temperature for flotation was as low as 8 °C, and this flotation method also could be applied to different types of zinc oxide ores. Under optimum flotation conditions, a concentrate with a Zn grade of 48.34% and a Zn recovery of 95.97% was obtained.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 1; 149--158
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zinc oxide as a functional admixture to cement composites
Autorzy:
Klapiszewska, Izabela
Ławniczak, Łukasz
Parus, Anna
Jesionowski, Teofil
Klapiszewski, Łukasz
Ślosarczyk, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/2146946.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
zinc oxide
admixtures
cement composites
antimicrobial tests
Opis:
There is an increasing trend in the modern construction industry to use nanomaterials, which allow to improve the performance of construction materials on the one hand, and to shape new properties on the other. This study presents the results of physicomechanical and antibacterial tests for cement composites modified with zinc nanooxide. The main aim of this study was to compare the structural and morphological properties of three selected commercial zinc nanooxides and to determine the influence of the above mentioned nanooxides on the physicomechanical properties of cement composites and the ability to inhibit the activity of gram-positive and gram-negative bacteria as well as fungi. It was shown that commercial nanooxides can significantly differ in terms of physicochemical properties, which depend on their production method. Two of them were characterized by high specific surface areas, which in turn translated into rheological properties of cement mortars. Nanooxides with higher specific surface areas tend to reduce the plasticity of the mortars. According to the literature data, all nanooxides caused a delay in cement binder setting by more than 100%. This resulted in a reduction of the early one-day flexural and compressive strength of the composite. In the later curing period, especially after 7 days of hardening, a significant acceleration of the hydration process was observed in composites with the addition of all nanooxides, which was confirmed by significant increases in mechanical parameters. Nevertheless, the tested nanooxides showed different sensitivity towards microorganisms, which was influenced by both the type of nanooxide and bacteria.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 2; art. no. 145565
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of different zinc compounds from a smithsonite ore through ammonia leaching and subsequent heat treatment
Autorzy:
Ehsani, Arman
Ehsani, Ilhan
Obut, Abdullah
Powiązania:
https://bibliotekanauki.pl/articles/1445772.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ammonia leaching
smithsonite
zinc ammine carbonate
zinc carbonate hydroxide
zinc oxide
Opis:
In this study, firstly, the effects of ammonia concentration, leaching time and solid/liquid ratio on the leaching behaviour of zinc from a smithsonite (ZnCO3) ore sample in aqueous ammonia solutions were investigated at room temperature by chemical, X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) spectroscopy analyses. It was found that leaching ratio of zinc steeply increased from 30.1 to 76.2% with increasing ammonia concentration from 1.0 to 4.0 M and maximum zinc leaching ratio of 79.7% was reached after leaching in 13.3 M NH3 solution. The XRD pattern of the residue obtained after leaching in 4.0 M NH3 solution for 90 min at solid/liquid ratio of 0.15 g/mL, the optimum condition, showed that smithsonite phase in the ore sample almost completely dissolved whereas the gangue minerals goethite and calcite remained unaffected, confirming the selectivity of ammonia solution for zinc dissolution. Together with zinc, leaching ratios of cadmium were also determined. In second part of the study, precipitation tests (by complete drying at different temperatures) were conducted on dissolved zinc, carbonate and ammonia containing pregnant solutions obtained after selected leaching experiments. By complete drying of the pregnant solutions at low temperatures, i.e. 50°C, relatively pure solid zinc ammine carbonate (Zn(NH3)CO3) precipitates and at higher temperatures, i.e. 150°C, quite pure solid zinc carbonate hydroxide (Zn5(CO3)2(OH)6) precipitates could be prepared. High-temperature heating of Zn(NH3)CO3 and Zn5(CO3)2(OH)6 precipitates at 450°C yielded single-phase zinc oxide (ZnO). The chemical compositions, FT-IR spectra and scanning electron microscope (SEM) photographs of some of the precipitates were also presented.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 4; 96-106
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of heating on structure and leaching characteristics of a zinc carbonate ore
Autorzy:
Kumas, Cavit
Obut, Abdullah
Powiązania:
https://bibliotekanauki.pl/articles/1446908.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
calcium zincate
smithsonite
sodium hydroxide leaching
zinc carbonate ore
zinc oxide
Opis:
In this work, the structural changes occurred in a zinc carbonate (smithsonite) ore sample following heating at temperatures between 523 K and 1173 K were investigated in detail using X-ray diffraction (XRD), thermal (TG/DTA) and Fourier-transform infrared (FT-IR) spectroscopy analyses. Afterwards, the leaching characteristics of zinc from the ore sample and the heated ore samples in sodium hydroxide solutions were determined. While heating at 523 K did not cause any structural change in the ore sample, heating at 723 K completely converted smithsonite $(ZnCO_3)$ in the ore sample to zinc oxide $(ZnO)$, which resulted lower zinc leaching efficiencies of 40.6% and 62.0% for 3 and 4 mol/dm3 NaOH concentrations, respectively, in comparison to zinc leaching efficiencies (67.2% and 70.7%) obtained for the unheated ore sample. On the other hand, due to neoformation of dissolution resistant $ZnFe_2O_4$, $Ca_2ZnSi2O_7$ and $Zn_2SiO_4$ phases during heating and formation of $CaZn_2(OH)_6∙2H_2O$ phase during leaching, the leaching efficiency of zinc further decreased to 22.2% and 31.3%, respectively, in 3 and 4 $mol$ / $dm^3$ NaOH solutions for the ore sample heated at 1173 K. The formation of zinc-containing dissolution resistant phases by high-temperature heating was observed to be the only reason for the reduction in the zinc leaching efficiency (49.4% at 1173 K) at the highest NaOH concentration (8 mol/dm3) studied. In this work, the comparative precipitation studies were also conducted and crystalline zinc oxides with different morphologies could be precipitated at considerably high efficiencies from the selected pregnant solutions obtained following leaching.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 5; 23-32
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical approach to the production of cement composites doped with ZnO and ZnO-based materials
Autorzy:
Klapiszewska, Izabela
Balicki, Sebastian
Wilk, Kazimiera A.
Klapiszewski, Łukasz
Ślosarczyk, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/24085675.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cement composite
zinc oxide
hybrid materials
design of experiments
Opis:
In this study, physical and functional properties of the cement composites containing ZnO, ZnO/lignin and lignin admixtures were investigated using Response Surface Methodology (RSM). The I-optimal design based on RSM was used to assess the influence of ZnO-based doping agent, of either commercial or synthetic origin, on cement composite production in the function of average compressive strength and cost. Polynomial mathematical models were developed by RSM confronting results from the experimental design. The accuracy and precision of the utilized models established by I-optimal design were tested using Analysis of Variance (ANOVA). The first stage of formulation optimization revealed that the use of commercially available ZnO-based admixture no. 4 (ZnO-SA, supplied by Sigma Aldrich) allowed to achieve the desired results, passing all the requirements, i.e., the best microbial purity combined with reasonable cost, followed by satisfactory physical properties. In the second stage of formulation optimization, the influence of implementing the hybrid materials, i.e., ZnO-SA mixed in different proportions with lignin was evaluated. RSM revealed that doping admixture no. 3, i.e., ZnO-SA/lignin (5:1), is the best candidate, which comprised augmented functional and physical properties of the fabricated cement composite. This component exhibited the best microbial purity as well as the lowest total pore volume, followed by satisfactory physical properties. Verification of the model findings indicated considerable agreement between the predicted and experimental values. From the findings, it was confirmed that a reasonable cost-performance balance for cement composites can be achieved using ZnO-SA and ZnO-SA/lignin (5:1).
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 4; art. no. 168352
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on separation of low-grade zinc oxide ore with sulfurization-amination flotation
Autorzy:
Feng, Dongxia
Bai, Lin
Xie, Haiyun
Tong, Xiong
Powiązania:
https://bibliotekanauki.pl/articles/109605.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low-grade zinc oxide ore
sulfurization-amination flotation
grinding fineness
Opis:
With the continuous depletion of a large number of zinc sulphide ores that are easy to treat, the finely disseminated and refractory low-grade zinc oxide ores has become an important source for the production of zinc minerals. In this paper, a sulfurization-amination flotation process has been proposed for concentrating large amounts of low-grade zinc oxide ore in Lanping, Yunnan Province. Spectrum analysis, chemical analysis and element analysis was performed to provide research basis for process design and operational control. The main influencing factors during the process, including grinding fineness, reagent types and dosage, etc., have been studied through flotation tests. The results showed that the optimum grinding fineness was -0.074 mm accounting for 89.78% for the target run-of mine ore. Moreover, optimum dosages of sodium carbonate, sodium silicate, sodium hexametaphosphate, sodium sulphide and octadecylamine were determined as 1500 g/t, 500 g/t, 200g/t, 8000 g/t and 500 g/t, respectively. Under these conditions, an open circuit test and a closed circuit test with one stage rougher, two stage scavenger and three stage cleaner flotation were carried out with the run-of-mine ore with a zinc grade of 6.52% and the oxidation ratio of 94.62%. The zinc concentrate can be obtained with zinc grade of 44.09% at a zinc recovery of 66.35% with a 9.70% yield of zinc concentrate yield. The results confirmed the validity and practicability of the proposed process design and experimental operation. This study is of special value as it provides referencing significance for economically exploiting low-grade zinc oxide ore.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1082-1090
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrometallurgical treatment of non-sulfide zinc ore for precipitation of zinc oxide nanoparticles
Autorzy:
Abdel-Aal, E.-S. A.
Rashad, M. M.
El-Shazly, A. N.
Ibrahim, I. A.
El-Shahat, M. F.
Powiązania:
https://bibliotekanauki.pl/articles/110748.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
zinc ore
sulfuric acid leaching
filtration rate
zinc sulfate
zinc oxide nanoparticles
MB photocatalytic degradation
Opis:
Acid leaching of Egyptian zinc ore from the Um Gheig area was carried out with sulfuric acid. This study determines the optimum conditions for dissolution of non-sulfide zinc ore. The optimum conditions are 25% -74m particle size, 45 °C temperature, 2 h leaching time, 1.1 stoichiometric molar ratio of H2SO4 to Zn, 1:3 solid/liquid ratio. The maximum filtration rate is 1.6 Mg Zn•m-2•day-1at pressure difference of 0.80 bar. The zinc recovery is about 90%. As the zinc ore contains zinc silicate, some additives were tested to enhance filtration and prevent formation of silica gel. To increase the added value of the product, zinc oxide was precipitated by a co-precipitation method in a nanosize powder with average particle size ~ 20 nm. Photocatalytic degradation of methylene blue dye under UV light using ZnO nanopowders produced at different conditions was investigated. Photocatalytic efficiency with methylene blue (MB) concentration was reduced as much as 85% in 240 min with the produced nanoparticles.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 729-737
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex electrothermal processing of an oxide zinc-containing ore of the Shaymerden deposit
Autorzy:
Shevko, V.
Karataeva, G.
Tuleev, M.
Badikova, A.
Amanov, D.
Abzhanova, A.
Powiązania:
https://bibliotekanauki.pl/articles/110855.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
calcium carbide
electrosmelting
zinc-containing oxide ore
ferroalloy
zinc sublimates
Opis:
Oxide ores are potential world raw materials sources of zinc manufacture. Despite a sufficiently high extraction level of zinc and lead known pyrometallurgical methods are characterized by formation of large quantity of industrial wastes therefore a complex use level of these raw materials is low. Hydrometallurgical methods are mainly applied for extraction of nonferrous metals. The present article contains the research results of complex processing an oxide ore of the Shaymerden deposit (Kazakhstan), consisting in the simultaneous production of a ferroalloy, calcium carbide and zinc sublimates from the ore in a thermal-ore arc electric furnace. The researches have been carried out with use of a HSC 5.1 software package (based on a principle of Gibbs energy minimum) and electrical smelting the ore in a monoelectrode arc electric controlled-output furnace. It was found, that in equilibrium conditions in a system ore-carbon-iron gaseous zinc is formed at Т > 1073 K, FeSi at Т > 1573 K, CaC2 at Т > 2073 K, Si at Т > 1673 K. The electrosmelting of ore in an arc furnace using of 38.7-40% coke and 16-28.4% steel cuttings the conversion degree of silicon into an alloy is 75-77%, calcium to calcium carbide 77-81%, zinc to sublimates 99.3%. The ferroalloy obtained contains 19.6-41.3% of silicon, the calcium carbide is characterized by capacity of 110-250 m3/kg, and the zinc sublimates contain 66-67% of zinc. The -suggested method allows to increase the combined usage of the ore from 35.6 to 89.6%.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 955-964
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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