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Wyszukujesz frazę "fine coal flotation" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Effect of swelling clay dispersion type on fine coal flotation
Autorzy:
Zhang, Mingqing
Yu, Wei
Cao, Yijun
Xu, Haiyu
Powiązania:
https://bibliotekanauki.pl/articles/110246.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fine coal flotation
swelling clay
controlled dispersion
CaCl2
slime coating
Opis:
The influence of bentonite dispersion on fine coal flotation was examined to better understand the role of swelling clay in the process of flotation. It was found that the coal flotation recovery was lower with uncontrolled dispersion of bentonite than with controlled dispersion. The detrimental effect was attributed to the increase in slime coating. In the uncontrolled dispersion, the dispersed bentonite platelets formed an extensive card-house structure. The three-dimensional networks increased the slurry viscosity, and caused significant coating of the coal particles, thereby inhibiting particle mobility and bubble-particle attachment. In the controlled dispersion, the bentonite mineral appeared as separate particles with low aspect ratios. The coal particles were partially coated, and the slurry viscosity was lower, resulting in higher flotation recovery. The findings in this study suggested that a practical solution to mitigate the negative impact of swelling clay on flotation would be to maintain high electrolyte levels in the wash water to inhibit clay swelling and dispersion.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 380-388
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of two-stage stirred pulp-mixing on coal flotation
Autorzy:
Gui, X.
Wang, Y.
Zhang, H.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/110764.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mixing
stirred
two stage
fine coal
flotation
Opis:
Stirred pulp-mixing is performed before coal flotation. In this study, a two-stage stirred pulpmixing tank was designed based on the single-stirred process to intensify the mixing effect of pulp and flotation reagents. A tank has a pitched-impeller opening-type turbine. Stirred pulp-mixing and flotation experiments were conducted on a sample of anthracite fine coal (-0.5mm) from the Xuehu Coal Preparation Plant in Henan Province, China. The results of the two-stage stirred pulp-mixing were compared with those of a single-stage stirred pulp-mixing in terms of flotation performance. Compared with the single-stage stirred pulp-mixing, two mixing areas and double-layer impeller were able to strengthen the energy input to the stirred system, thereby improving the mixing efficiency of flotation reagents and coal particles in the pulp. The two-stage stirred pulp-mixing significantly increased the flotation feed rate of the cyclone-static micro-bubble flotation column and concentrate yield, enhanced the combustible matter recovery effect of coarse particles at a suitable flotation feed rate, and ensured the recovery effect of fine particles at high flotation feed rate.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 299-310
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deashing and desulphurization of fine oxidized coal by falcon concentrator and flotation
Autorzy:
Zhu, X.
Tao, Y.
Sun, Q.
Man, Z.
Xian, Y.
Powiązania:
https://bibliotekanauki.pl/articles/951856.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fine oxidized coal
desulphurization
deashing
flotation
enhanced gravity separation
Opis:
Flotation and enhanced gravity separation based on different separation principles were carried out to investigate the desulphurization and deashing efficiency of fine oxidized coal. Surface properties of fresh and oxidized coals were tested by XPS and results showed that the contents of hydrophobic functional groups decreased while the content of hydrophilic functional groups increased after oxidization. Floatability and density analysis results showed that the floatability of coal samples decreased sharply because of oxidation, however, density composition of coal sample only had slight changes. Separation results showed that yields of gravity concentrates outclassed that of flotation concentrates, meanwhile, ash contents and sulfur contents of gravity concentrates were far lower than that of flotation concentrates. Yields and ash contents increased with the collector dosage and achieved to be 17.83 and 26.94% respectively when the collector dosage was 1600 g•Mg-1. Yields and ash contents of gravity concentrates decreased with the centrifugal force and increased with the recoil water flow with similar sulfur content. Clean coal with yield of 53.86%, ash content of 9.81%, sulfur content of 1.47% and with a corresponding desulphurization efficiency of 44.53% was achieved at centrifugal force of 107 g and recoil water flow of 13.3 dm3•min-1. For fine oxidized coal, enhanced gravity separation has a significant advantage of the separation efficiency compared with flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 634-646
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation behavior of hard-to-separate and high-ash fine coal
Autorzy:
Xing, Y.
Gui, X.
Liu, J.
Cao, Y.
Zhang, Y.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/110585.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation behavior
fine coal
Fuerstenau upgrading curve
energy input
selectivity
Opis:
The flotation behavior of hard-to-separate and high-ash fine coal was investigated using conventional flotation with constant power input. A new flotation process, based on energy input and distribution, was designed to lower the ash content of concentrate. The results obtained using Fourier transform infrared (FTIR) analysis show that the coal samples have good floatability because of many hydrophobic and few hydrophilic functional groups. Under a constant power input, a large number of ash-forming materials floated into a froth product at the start of flotation. Based on the Fuerstenau upgrading curves, it was determined that the 0.25-0.074 mm size fraction range showed the worst selectivity when compared with 0.50-0.25 mm and -0.074 mm size fractions. The desired concentrate with an ash content of 13.98%, 27.59% of ash recovery, and 80.01% combustible matter recovery could be obtained by transferring the excess energy of the flotation-conditioning stage to the pre-conditioning stage and increasing the power input step-by-step in the flotation-conditioning stage at equal total energy consumption.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 703-717
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding the difficult selective separation characteristics of high-ash fine coal
Autorzy:
Yang, Zili
Liu, Min
Chang, Guohui
Xia, Yangchao
Li, Ming
Xing, Yaowen
Gui, Xiahui
Powiązania:
https://bibliotekanauki.pl/articles/1845210.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high-ash fine coal
flotation
rod grinding
floatability
slime coating
Opis:
As the supply of high-quality coals decreases and mechanical coal mining becomes more widespread, the high selective recovery of high-ash fine coal has become a prominent problem in the flotation process. Herein, we discuss the main reasons why the selective separation of high-ash fine coal is difficult. The analysis of high-ash fine coal properties shows that coarse particles (0.25-0.5 mm) account for 22.53% of the total size fraction and that 57.90% of the coal is moderate- or high-density (+1.4 g/cm3) intergrowth. Grinding experiments show that the traditional rod mill has little impact on the liberation of the intergrowth. Instead, its main function is to adjust the particle size composition to ensure that the particle sizes of high-ash fine coal are within the particle size range suitable for flotation. The flotation results show that a clean coal yield of 30.42%, with a 12.46% ash content, is obtained with the optimal flotation parameters through the roughing and cleaning flotation process. However, the flotation results also show that in the separation of high-ash fine coal, it is difficult to obtain clean coal with a high yield and low ash content at the same time. This is mainly due to the similar floatability of moderate-density and low-density coal particles, which allows a large number of moderate-density coal particles to be recovered, and a significant slime coating of clay on the coal’s surface that is generated during the flotation process. The results of this work provide valuable guidance for high-ash fine coal industrial flotation applications.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 874-883
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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