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    Wyświetlanie 1-5 z 5
    Tytuł:
    Study on the mechanism of the difference in flotation performance between fine-grained crystalline SiO2 and amorphous SiO2
    Autorzy:
    Ma, Saisai
    Li, Jie
    Wang, Yonglun
    Wei, Bangqi
    Powiązania:
    https://bibliotekanauki.pl/articles/27323646.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    flotation separation
    heteromorphism
    infrared spectrum calculation
    DLVO theory
    Opis:
    Numerous minerals found in nature contain silica, including quartz, cristobalite, opal, etc. They have the same chemical composition but different crystal structures, and this phenomenon is called “polymorphism” in mineralogy. For these polymorphic and multi-like minerals, in the flotation process, will it directly or indirectly affect the flotation effect. Based on this, this study mainly explores the difference between crystalline SiO2 and amorphous SiO2 in flotation. In this study, two crystal forms of SiO2 were subjected to flotation and adsorption capacity tests. FTIR, other test techniques, the chemical calculation of the flotation solution, and the theoretical calculation of the DLVO can all be used to provide an explanation. Finally, in the flotation experiment, the feedbacks of the two minerals to the change of the pH value of the pulp and the change of the concentration of the reagent are different. Through the comprehensive analysis of the adsorption capacity test and semi-quantitative calculation of the infrared spectrum, the adsorption capacity of crystalline SiO2 to drugs is about 23% higher than amorphous SiO2. Furthermore, during the flotation process, the amorphous SiO2 particles will agglomerate together and entrain into the foam through, resulting in concentrate pollution. So amorphous SiO2 will undoubtedly increase the difficulty of flotation.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 174567
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect and mechanism of citric acid on flotation separation of siderite and hematite
    Autorzy:
    Han, Huili
    Yin, Wanzhong
    Yao, Jin
    Li, Dong
    Powiązania:
    https://bibliotekanauki.pl/articles/949693.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    siderite
    hematite
    citric acid
    dispersion
    flotation
    E-DLVO theory
    Opis:
    Heterocoagulation can occur between fine siderite and hematite particles, which would result in the low efficiency of their separation during the flotation process. To date, there have been no mature methods to increase their separation efficiency. In this paper, citric acid was used as a regulator to enhance the slurry dispersion efficiency. Micro-flotation, scanning electron microscopy (SEM) analysis, settling tests, particle size measurements, zeta potential measurements and E-DLVO theoretical calculations were conducted in the investigations. A maximum recovery difference (53.98%) between siderite and hematite in their mixtures flotation was obtained. Settling tests confirmed that citric acid contributed to improving the dispersion degree of the slurry. SEM analysis indicated that citric acid could clean the surface of particles and weaken the coagulation between siderite and hematite, which were in line with the results of particle size measurements. The zeta potential measurements and Extended-Derjaguin-Landau-Verwey-Overbeek (E-DLVO) theoretical calculations indicated that the citric acid could adsorb on the siderite and hematite surfaces and decreased the surface charge, resulting in a visible increase of the repulsion energy between siderite and hematite particles. Therefore, citric acid can be applied to remove the easily-ground carbonate minerals first to improve the flotation performance of hematite in the separation process of carbonate-containing iron ores.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 1; 311-323
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study on condition prediction and influencing factors of manganese carbonate recovery by high gradient pulse magnetic separation
    Autorzy:
    Wang, Zhenggang
    Nie, Guanghua
    Tang, Yun
    Piao, Haishan
    Chen, Jian
    Powiązania:
    https://bibliotekanauki.pl/articles/24085829.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    mineral particles
    impulse
    volume susceptibility
    magnetic field strength
    DLVO theory
    Opis:
    Manganese carbonate ore belongs to weakly magnetic minerals, and its co-associated minerals are mainly non-magnetic minerals, which can be separated from gangue minerals at high magnetic field intensity. However, manganese grade and recovery of magnetic separation concentrate of manganese carbonate ore are low in actual production. Therefore, the influences of manganese carbonate particle size, magnetic field intensity, volume susceptibility, pulse stroke, pH, and other factors were studied. The optimal test conditions for manganese carbonate ore recovery by high-gradient magnetic separation were predicted through the calculation results. The results show that the particle radius of manganese carbonate is 0.020 mm, the pulse impulse time is 200 r/min, and the magnetic field intensity is 0.9 T. The optimum condition test was carried out with Qianbei manganese carbonate ore as the material. The test results show that the optimum conditions are the particle radius of 0.074-0.019 mm, pulse impulse time of 200 r/min, and magnetic field intensity of 1.2 T. The reason for the deviation is that the actual ore has a fine distribution particle size, many associative bodies, complex composition, and serious agglomeration, resulting in variable particle volume susceptibility. The capture yield increases with the increase of magnetic field intensity and volume susceptibility but decreases with the increase of pulse. The lower the surface potential of manganese carbonate, the higher the recovery of manganese carbonate. The grade of manganese concentrate was 19.06% and the recovery was 76.85%. Mixed manganese concentrate with a grade of 18.04% and recovery of 87.14% was obtained by adding drugs and changing the grinding method.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 168668
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effects of monovalent and divalent ions in coal gasification brine on the froth entrainment and flotation kinetics of anthracite coal
    Autorzy:
    Zheng, Kaidi
    Bu, Xiangning
    Zhou, Shaoqi
    Zhang, Jing
    Shao, Huaizhi
    Sha, Jie
    Xie, Guangyuan
    Powiązania:
    https://bibliotekanauki.pl/articles/1845216.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    coal gasification brine
    salts ions
    coal flotation
    entrainment
    flotation kinetics
    DLVO theory
    Opis:
    Water plays a critical role in various stages of flotation, which brings a lot of pressure to the flotation processing plants resided in dry areas. In this regard, it will be of significance to explore the feasibility of using wastewater resources in mineral flotation. Coal gasification brine (CGB) that contains a high concentration of salts becomes the subject of interest of this study. In this study, a synthetic CGB solution, which was prepared by adding NaCl, MgCl2, and CaCl2 to ultrapure water based on the composition of salts in a real CGB, was used in the flotation of anthracite coal. The comparison results based on the first-order model showed that flotation in the presence of the synthetic CGB solution gave a higher flotation selectivity (SI =7.086) than that of flotation in ultrapure water (SI=3.545). Water recoveries and average bubble sizes in the froth showed that the addition of the three salt ions (Na+, Mg2+, and Ca2+) was conducive to diminishing the entrainment of gangue materials as a result of the reduction of water reporting to the froth. Additionally, the zeta potentials and induction time measurements indicated that only divalent ions of Ca2+ and Mg2+ significantly compressed the double electrical layer and enhanced the attachment between bubbles and coal particles according to DLVO theory, which was further confirmed by the calculation of interaction energy between coal and bubbles. The findings of the present work may promote the use of CGB as a potential water resource in coal flotation.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2020, 56, 5; 960-974
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study on the floc-bubble adhesion behavior of hematite in static flow field
    Autorzy:
    Zhang, Jinxia
    Feng, Hongjun
    Niu, Fusheng
    Sun, Weiguang
    Zhao, Yawei
    Powiązania:
    https://bibliotekanauki.pl/articles/1449769.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    bubble
    floc
    adhesion
    charge-coupled device (CCD) camera
    Derjaguin-Landau-Verwey-Overbeek (DLVO) theory
    Opis:
    To investigate the adhesion of hematite flocs to gas bubbles in floc floatation, this paper develops an observation system for floc-bubble collision and adhesion with two charge-coupled device (CCD) cameras. The sizes of flocs and bubble were 45.36μm and 0.90mm, respectively, and the distance between a floc and the bubble center (sedimentation distance) was set to 0.25cm. Three surfactants, namely, sodium oleate, lauryl amine and sodium dodecyl sulfate (SDS), were selected for our research. Several experiments were conducted to disclose how surfactant concentration and pH affect the surface adhesion between hematite flocs and bubbles. Then, the adhesion mechanism was discussed in details based on the experimental results. The results show that the highest adhesion probability was achieved for the said floc and bubble at the lauryl amine concentration of 8mg/L, the sedimentation distance of 0.25cm and the pH of 9. After touching the bubble, the hermamite floc slid on the bubble surface, forming a stable three-phase interface after 67ms. Then, the radial position of the floc no longer changed, despite the floc motion on the bubble surface. According to the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the potential energy of the van der Waals force, there was a repulsive force between the floc and the bubble in the absence of surfactant and an attractive force in the presence of the surfactant of lauryl amine. In addition, a thin solvation shell is conducive to the adhesion between the floc and the bubble.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2020, 56, 1; 124-133
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-5 z 5

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