Search

Gossan ore is typically abandoned after mining, which not only increases mining production costs but also wastes mineral resources, and its long-term accumulation can easily lead to environmental pollution hazards. Therefore, this paper takes zinc-containing gossan ore as the research object and, based on the high content of zinc and iron minerals in gossan ore, this study conducts a roasting experiment to prepare ZnFeO4. X-ray diffraction is used to characterize and analyze the ZnFeO4 sample prepared by roasting zinc-containing gossan ore. The experimental results indicate that controlling the particle size of the roasted ore sample to −0.074 mm can effectively remove impurities and facilitate the reaction. The influence of roasting temperature and time on the formation of ZnFeO4 is remarkable. The conditions for roasting zinc-containing gossan ore to maximize the ZnFeO4 content are as follows: −0.074 mm particle size ore sample, reaction zinc/iron molar ratio of 1:2, mechanical activation time of 120 min, roasting temperature of 1050 °C, and roasting time of 120 min. These findings provide new ideas for the utilization of gossan ore and lay a theoretical foundation for the efficient development and utilization of difficult-to-select zinc-containing gossan ore. [ABSTRACT FROM AUTHOR]

Herein, a novel conducting polymer complex PEDOT:CF3SO2(x)PSS(1‐x) [denoted as S‐PEDOT:CF3SO2(x)PSS(1‐x), where PEDOT is poly(3,4‐ethylenedioxythiophene) and PSS is poly(styrene sulfonate)], is fabricated with the assistance of zinc di[bis(trifluoromenthylsulfonyl) imide][Zn(TFSI)2] (CFE). The introduction of CF3SO2− group is expected to bring better stability of PEDOT:CF3SO2 than PEDOT:PSS due to its strong Coulomb force. Electrochemical measurement shows that a high specific capacitance of 194 F cm−3 was achieved from the novel complex S‐PEDOT:CF3SO2(x)PSS(1‐x), the highest value reported so far. An all‐solid‐state supercapacitor assembly with a structure of S‐PEDOT:CF3SO2(x)PSS(1‐x)/H2SO4:polyvinyl alcohol (PVA)/S‐PEDOT:CF3SO2(x)PSS(1‐x) shows a record specific capacitance of 70.9 F cm−3 and a maximum energy density of 6.02 mWh cm−3 at a power density of 397 mW cm−3. This supercapacitor device demonstrates excellent electrochemical stability with a capacitance retention rate of 98 % after 10 000 cycles and extreme air stability of 96 % capacitance retention rate after 10 000 cycles, even if the device is exposed to air over 2880 h, much better than that of PEDOT:PSS based supercapacitors. Excellent capacitance can be achieved from PEDOT:CF3SO2(x)PSS(1‐x) electrode under electrolyte‐free conditions. This work provides a novel method for high performance stable supercapacitors and may pave the way for the commercialization of PEDOT based supercapacitors. [ABSTRACT FROM AUTHOR]

The relationship between the grinding characteristics of polymetallic complex ore and its component minerals, pyrrhotite, sphalerite, and quartz, under the action of abrasion was studied, based on batch grinding experiments and theoretical analysis methods of selective grinding. The results show that when the polymetallic complex ore was subjected to the action of abrasion, the crushing effect of ore was enhanced by the existence of sphalerite, that is, sphalerite plays a positive role in the crushing effect of ore. The crushing effect of ore was reduced by the existence of pyrrhotite and quartz, that is, pyrrhotite and quartz plays a negative role in the crushing effect of ore. In addition, the sphalerite had a more prominent effect on the grinding characteristics of the ore. The grinding speed of ore and its component minerals decreased exponentially with the grinding time, and the instantaneous grinding speed of 0 min was negatively correlated with the feed sizes. The rapidly decreasing trend of the grinding speed reached the threshold when the grinding time reached 4 min. The results can provide some theoretical guidance for the study of grinding characteristics of multi-component complex ores in subsequent grinding process. [ABSTRACT FROM AUTHOR]

Recently, researchers have proven the therapeutic properties of copper nanoparticles as a common product of nanotechnology science. Due to the excellent antioxidant potential of copper nanoparticles, it seems that they can be used for the treatment of infectious diseases and cutaneous wounds. Also, Allium eriophyllum Boiss leaf is used in Kurdish traditional medicine, as one of the popular medicines of the Iranian traditional medicines, for increasing the trend of wound healing. So, we decided to synthesize the copper nanoparticles containing A. eriophyllum leaf aqueous extract, and analyze their potentials in removing bacteria and fungi and healing of cutaneous wounds. After synthesizing the copper nanoparticles, they were characterized with common techniques of organic chemistry, i.e. UV–Vis, Fourier transform‐infrared, X‐ray diffraction, field emission‐scanning electron microscopy (FE‐SEM) and transmission electron microscopy (TEM). For investigating the antimicrobial properties of CuSO4, A. eriophyllum, and CuNPs@A. eriophyllum, we used the macro‐broth dilation test. Also, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) of CuSO4, A. eriophyllum, and CuNPs@A. eriophyllum were gained to indicate the exact antimicrobial potentials of them. To survey the cutaneous wound‐healing effects of CuSO4, A. eriophyllum, and CuNPs@A. eriophyllum, the 0.2% ointments were formulated and compared with the control and untreated groups. All data of antimicrobial and cutaneous wound‐healing experiments were assessed by SPSS 22 software. The results of chemical characterization indicated that copper nanoparticles had been synthesized as the best form, and the size ranges were 25–35 and 30–35 nm in the FE‐SEM and TEM images, respectively. In the antimicrobial part of this study, CuNPs@A. eriophyllum indicated higher antifungal and antibacterial effects than all standard antibiotics (P ≤ 0.01). MIC, MBC and MFC of CuNPs@A. eriophyllum were 2−4 mg/ml against all fungi and bacteria tested. With regard to cutaneous wound healing, the use of CuNPs@A. eriophyllum ointment significantly (P ≤ 0.01) raised the wound contracture, vessel, hydroxyl proline, hexuronic acid, hexosamine, fibrocyte and fibrocytes/fibroblast rate, and significantly (P ≤ 0.01) decreased the wound area, total cells, neutrophils and lymphocytes compared with other groups in rats. According to the above findings, CuNPs@A. eriophyllum may be used for the treatment of infectious diseases and cutaneous wounds in humans. [ABSTRACT FROM AUTHOR]