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Tytuł:
Extraction and separation of zinc, lead, silver, and bismuth from bismuth slag
Autorzy:
Xing, Peng
Ma, Baozhong
Wang, Chengyan
Chen, Yongqiang
Powiązania:
https://bibliotekanauki.pl/articles/109744.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bismuth
zinc
lead
silver
extraction
separation
Opis:
The present paper deals with the extraction and separation of zinc, lead, silver, and bismuth from a refractory bismuth refining slag via a hydrometallurgical route. The process consists of a preliminary leaching of zinc with water, followed by the selective leaching of lead and silver with a calcium chloride solution, leading to the crystallization of lead chloride and the cementation of silver. The diagrams of the total concentrations of [Pb]/[Ag] versus [Cl-] and temperature in the Pb/Ag-Cl-H2O system were drawn, respectively, to determine the optimum concentration of leaching agent and leaching temperature. The potential-pH diagram of the Pb/Ag/Bi-H2O system indicates that the preferential leaching of lead and silver could be achieved. Finally, 98.8% of lead and 90.4% of silver were selectively removed by further leaching the water leaching residue with 400 g/dm3 of CaCl2 solution at pH 4.5 and 80 °C, while only 3.7% of bismuth was leached in this stage. Fifty-nine percent of lead in the leach liquor was separated out as PbCl2 by natural cooling. Ninety-five percent of silver in mother liquor was recovered by cementation with a lead sheet. The depleted CaCl2 solution can be sent to the leaching step again to close the loop.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 173-183
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wettability of quartz particles at varying conditions on the basis of the measurement of relative wetting contact angles and their flotation behaviour
Autorzy:
Gao, Shuling
Ma, Lifeng
Wei, Dezhou
Shen, Yanbai
Powiązania:
https://bibliotekanauki.pl/articles/109832.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
relative wetting contact angle
Washburn technique
surface free energy
flotation behaviour
sodium oleate
Opis:
In this paper, on the basis of a modified Washburn equation, the squared incremental pressure due to liquid rising vs. time were measured instead of wicking distances before reaching equilibrium, and the relative wetting contact angles (RWCA) were applied to characterize the surface wettability of quartz particles conditioned at different concentrations of flotation reagents. Combined with the flotation experiments on quartz particles at corresponding conditions, the relationship between flotation recoveries and RWCA was analysed, which proves that RWCA can characterize the surface wettability of quartz particles accurately. The results also showed that the best reagent conditions for floating quartz are pH 12.0, a Ca2+ concentration of 1×10-3 mol/dm3 and a sodium oleate concentration of 0.75×10-3 mol/dm3, where the recovery of quartz is 86%. The surface tension of the filtrate of the pulp was determined by a fully-automatic tensiometer as well. Based on the measured values of RWCA and surface tension, the free energy changes (ΔG) before and after the adhesion of bubbles and particles per unit area at corresponding situations were calculated, respectively. The trends of ΔG varying with the concentrations of reagents were in close accordance with those of RWCA and the flotation recoveries, proving that it is more likely for particles having bigger contact angles to adhere to bubbles, resulting in a higher flotation recovery. These results give a more feasible and accurate approach to analysing the surface wettability and floatability of fine particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 278-289
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The adsorption mechanism of Al(III) and Fe(III) ions on bastnaesite surfaces
Autorzy:
Cao, Shiming
Cao, Yijun
Ma, Zilong
Liao, Yinfei
Powiązania:
https://bibliotekanauki.pl/articles/110208.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Al(III)
Fe(III)
bastnaesite
adsorption
Opis:
The adsorption mechanism of Al(III) and Fe(III) ions on bastnaesite surfaces was investigated by a combination of DFT calculation, XPS analysis, adsorption isotherm study and adsorption kinetic investigations. DFT calculation results indicated that ≡CeOH0 and ≡CO3H0 are primary functional groups on bastnaesite surfaces. XPS analysis reveals that Al(III) and Fe(III) ions adsorbed onto the bastnaesite surfaces through the interaction between aluminium/iron hydroxide species and oxygen atoms of surface ≡CeOH0 groups. No interaction between aluminium/iron hydroxide species and ≡CO3H0 groups was detected. Adsorption isotherm studies demonstrated that the adsorption data of Al(III) and Fe(III) ions is fitted relatively well by Freundlich equations, the adsorption kinetic characteristics fitted to pseudo-second order model. Freundlich constants suggested favorable process for Al(III) and Fe(III) ions adsorption, and each adsorbed metal hydroxide specie complex with at least two oxygen atoms of surface ≡CeOH0 groups.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 97-107
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism of ultrasonic cavitation to improve the effect of siderite on quartz flotation
Autorzy:
Yin, Wanzhong
Cai, Lizheng
Ma, Yingqiang
Wang, Ying
Powiązania:
https://bibliotekanauki.pl/articles/24085972.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultrasound treatment
cover
fine siderite
CaCO3 precipitate
Opis:
In order to effectively eliminate the effect of fine carbonate minerals on quartz flotation, the influence of fine siderite on quartz flotation was studied as well as the mechanism or role of ultrasonic treatment in the process. The results of adsorption capacity measurement and flotation solution chemical calculation show that fine siderite and its dissolved components have a great influence on the collector consumption and the surface properties of quartz. In addition, SEM, EDS and XPS analysis were used to study the surface morphology and chemical environment changes of quartz with and without ultrasonic treatment. The results of flotation test show that the recovery of quartz increase from 38.79% to 58.38% under the condition that ultrasonic time was 0.5 min and ultrasonic power was200 W. The mechanical effect caused by ultrasonic cavitation can clean the quartz surface to a certain extent and increase its active sites, thus improving the floatability of quartz.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 165930
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Study on feature extraction and dynamic properties of bubbles in a liquid-phase flow field
Autorzy:
Peng, Deqiang
Dong, Xianshu
Fan, Yuping
Ma, Xiaomin
Powiązania:
https://bibliotekanauki.pl/articles/109400.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bubbles
image processing
trajectory
probability distribution of diameter
terminal velocity
Opis:
To study the dynamic properties of bubbles generated at different air pressures in a liquid-phase flow field, this paper adopted high-speed camera technology and image processing techniques to extract and calculate the features of bubbles. The results showed that in a deionized water field, the bubbles generated at the air pressure of 0.1 MPa had an average diameter of 4.50 mm, and the bubbles generated at the air pressures of 0.2 MPa and 0.3 MPa had average diameters of 5.74 mm and 5.76 mm respectively; notwithstanding the insignificant differences in average data, the probability distribution of bubble diameter had significant differences with different pressures. During the rise of bubbles, their motion trajectory witnessed an increased amplitude of swing with the increase of air pressure; the bubbles generated at different air pressures did not show any significant differences in rising velocities though.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 268-277
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation behavior of nickel sulfide ore in a cyclonic flotation column
Autorzy:
Deng, L.
Li, G.
Cao, Y.
Ma, Z.
Powiązania:
https://bibliotekanauki.pl/articles/109906.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cyclonic flotation column
floatability
flotation
nickel sulfide ore
Opis:
This study aimed to show the flotation behavior of a nickel sulfide ore in a cyclonic flotation column. The flotation experiments were carried out using a sample of nickel sulfide ore obtained from a mineral processing plant of China. Representative samples collected from the feed, concentrate, tailing, and circulation middling were sieved using a cyclonic particle analyzer to collect different size fractions for analysis. The function of the column cyclonic zone of was evaluated by comparing the quality of tailing and circulation middling. The flotation results showed that the concentrate with Ni grade of 1.78% and recovery of 65.56% was obtained under given test conditions. The content of main sulfide minerals and coarse particles in the circulation middling was higher than that in the tailing. The results indicated that, unlike conventional cyclone classification, separation achieved in the cyclonic zone of the column was not dependent on the particle size and density. Sulfide minerals with good floatability were easily captured by bubbles and moved toward the center of the column, even if these particles were coarser and heavier.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 770-780
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption behavior and XPS analysis of nonylphenol ethoxylate on low rank coal
Autorzy:
You, Xiaofang
Ma, Chuandong
Li, Zhihao
Lyu, Xianjun
Li, Lin
Powiązania:
https://bibliotekanauki.pl/articles/109627.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low rank coal
nonylphenol ethoxylate
adsorption isotherm
adsorption kinetics
XPS
Opis:
In this work, low rank coal was used for the removal of nonylphenol ethoxylate with fifteen ethylene oxide groups (NPEO15) from aqueous solutions at different contact times, temperatures, and initial adsorbent concentrations. The adsorption isotherms showed good fit with the Langmuir equation. Maximum adsorption capacities calculated at 308, 318, and 328 K were 23.64, 29.41, and 35.71 mg g–1, respectively. The changes in the free energy of adsorption (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were calculated in order to predict the nature of adsorption. The results of the thermodynamic analysis indicated that a spontaneous process took place, driven synergistically by both enthalpy and entropy. The adsorption kinetics of NPEO15 were consistent with a pseudo-second order reaction model. XPS results showed that the oxygen functional groups on the low rank coal surface were significantly covered by NPEO15. Furthermore, while the content of C–C/C–H functional groups increased significantly, that of C–O functional groups decreased after absorption. These results clearly indicate that low rank coal is more hydrophobic and displays better floatability.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 3; 721-731
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strengthening the rough selection effect of n-ethyl o-isopropyl thionocarbamate (Dow: Z-200) on chalcopyrite by ultrasonic pretreatment
Autorzy:
Wang, Yan
Wang, Yubin
Yu, Bo
Wang, Xin
Ma, Xiaoxiao
Powiązania:
https://bibliotekanauki.pl/articles/1448798.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultrasonic pretreatment
Z-200
action mechanism
chalcopyrite flotation
Opis:
In this study, the properties of $(CH_3)_2CHOC(S)NHC_2H_5$(Dow: Z-200) after the ultrasonic pretreatment was characterized by employing surface tension, viscosity, and Fourier transform infrared (FTIR) spectroscopy, and its influence on chalcopyrite rough selecting was investigated. The results indicate that the pretreated Z-200 can improve the index of chalcopyrite roughing. And, under the same reagent system, the recovery of copper reached 82.84% which was an increase of 24.44% compared with the untreated when Z-200 after ultrasonic pretreatment was applied to the rough separation of chalcopyrite. The reason why ultrasonic can strengthen the flotation effect of Z-200 on chalcopyrite is that ultrasonic pretreatment can decrease the surface tension and viscosity of Z-200 and enhance its foaming performance. Meanwhile, the ultrasonic cavitation destroys the molecular structure of Z-200, so that the relative proportion of methyl absorption peak and amine absorption peak in Z-200 increases. This also further improves the collection performance and foaming performance of Z-200 and strengthens its separation effect on chalcopyrite. The research provides a new idea for Z-200 to act on chalcopyrite and improve its flotation efficiency, reduce the amount of flotation reagent, and its pollution to the environment. It also provides a theoretical basis for expanding the application of ultrasonic technology in the field of flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 1; 64-74
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of particle properties on rheology of low-concentration coal suspensions
Autorzy:
Hou, Jinying
Ma, Xiaomin
Fan, Yuping
Dong, Xianshu
Yao, Suling
Powiązania:
https://bibliotekanauki.pl/articles/1845222.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
apparent viscosity
coal suspension
particle property
hydrophobicity
effective volume
Opis:
In wet coal preparation, the products of some processes are transported as low-concentration suspensions. Their rheology is greatly affected by the properties of the coal particles that result from the formation and weathering during preparation. In this study, the properties of coal particles, including volumetric properties (i.e., solids content, granularity, and clay mineral fraction) and surface characteristics (i.e., dynamic potential, degree of coalification, and degree of surface oxidization), were studied to determine their effects on the apparent viscosity of low-concentration coal suspensions. With increasing solids content and smaller particle size in the suspension, the interactions between the coal particles became stronger due to the increased particle content, thus increasing the coal suspension’s apparent viscosity. Adding clay minerals to the suspension gradually changed its composition and structure and increased its viscosity. The dynamic potential of the coal particles and inter-particle electrostatic repulsive forces were reduced with the addition of Ca2+ ions, and the coal particles collided and aggregated, which increased the apparent viscosity of the suspension. For coal with a low degree of coalification or coal had been oxidized by a hydrogen peroxide solution, the suspension of the hydrophilic coal particles was associated with a lower apparent viscosity than that of highly hydrophobic solids, which tended to aggregate and form flocculent masses.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 984-995
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy feature of a multi-flow column flotation process
Autorzy:
Cheng, G.
Yu, Y.
Ma, L.
Xia, W.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/109768.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation column
turbulent kinetic energy
turbulent dissipation rate
bubble
Opis:
A cyclonic-static micro-bubble flotation column (FCSMC) has been widely used in mineral separation. FCSMC includes countercurrent, cyclone and jet flow mineralization zones in a single column. In this study, the energy feature of the three different zones was compared. The turbulent flow was evaluated in terms of the turbulent kinetic energy (k) and the turbulent dissipation rate (ε). An appropriate computing model was determined by comparing the flow field value measured by PIV with the results of the Fluent numerical simulation. Jet flow separation exhibited the maximum k and ε values among the three columns, whereas counter-current separation displayed the minimum values. The high circulating volumetric flowrate means great energy input and turbulent intensity. The higher turbulent dissipation rate, the smaller the bubble is. The better performance of the FCSMC was mainly attributed to the multiple mineralization steps. The floatability of mineral particles gradually decreases with an increase in flotation time, the mineralization energy gradually increased to overcome the decrease in mineral floatability. By contrast, the countercurrent was beneficial for recovering the coarse particles, and the jet flow was beneficial for recovering the fine particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1266-1284
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of ultrasonic pretreatment on the flotation behavior of galena with and without the presence of pyrite
Autorzy:
Lu, Dongfang
Chen, Lanlan
Ma, Yongyi
Zheng, Xiayu
Wang, Yuhua
Powiązania:
https://bibliotekanauki.pl/articles/1449431.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
galena
ultrasonic pretreatment
flotation
electrochemical reaction
Opis:
Utilizing the ultrasonic pretreatment, flotation tests, ICP-OES, and XPS analysis, the effect of the different ultrasonic pretreatment methods on the flotation behavior of galena were investigated. The flotation recovery of galena was improved for pretreated single galena sample, which is mainly attributed to the efficient removal of the oxidized components and contaminants on the surface of galena by the acoustic cavitation. However, the flotation recovery of galena was decreased when pretreated mixture sample of galena and pyrite was used. Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) and X-ray photoelectron spectroscopy (XPS) results reveal that ultrasonic pretreatment facilitates the conversion of $PbS$ to $Pb(OH)_2$ and $PbSO_4$. Besides, the flotation recovery of galena was affected to varying degrees when the galena was mixed with the pyrite of the different particle sizes in the ultrasonic pretreatment process. The reason is that the change in the surface area ratio of these two minerals affects the electrochemical reaction rate between galena and pyrite.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 611-624
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhancing low-rank coal flotation using a mixture of dodecane and n-valeraldehyde as a collector
Autorzy:
Liu, Zechen
Liao, Yinfei
An, Maoyan
Lai, Qingteng
Ma, Longfei
Qiu, Yuliang
Powiązania:
https://bibliotekanauki.pl/articles/109432.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mixed collector
oxygen-containing functional groups
adsorption mechanism
low rank coal
flotation
Opis:
Low-rank coals are difficult to float using common hydrocarbon oily collectors, such as dodecane and diesel. In this investigation, a mixture of dodecane and n-valeraldehyde was used as a collector to enhance low-rank coal flotation. The changes of the contact angle and surface functional groups of low-rank coal were measured before and after different collectors’ adsorption to indicate its absorption mechanism. Surface tension of different collectors was also measured to identify its spreading performance. The results showed that the flotation performance using the mixture as a collector was much better than that using dodecane or n-valeraldehyde solely. When used the mixture of dodecane and n-valeraldehyde as collector, dodecane primarily covers the hydrophobic sites while n-valeraldehyde primarily covered the hydrophilic sites by hydrogen bond promoting adsorption of dodecane at these sites. There existed synergistic effect between dodecane and n-valeraldehyde. Additionally, n-valeraldehyde can reduce the surface tensions to improve the spreading performance of mixed collector on low-rank coal surface. The improvement both in adsorption and spreading was responsible for the enhancement of low-rank coal flotation by using the mixture.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 49-57
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of particle size on flotation performance of hematite
Autorzy:
Luo, Ximei
Song, Shuixiang
Ma, Mingze
Wang, Yunfan
Zhou, Yongfeng
Zhang, Ying
Powiązania:
https://bibliotekanauki.pl/articles/109891.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle size
hematite
entrainment
surface bonding site
reagent adsorption
Opis:
The effect of particle size on flotation performance of hematite and quartz was investigated. Microflotation, X-ray photoelectron spectroscopy analysis, reagent adsorption measurements, and collision and attachment probability calculation between particle and bubble were conducted in this investigation. The results showed that the floatability of minerals with different particle size fractions was different, which was mainly related to surface bonding site, reagent adsorption, collision probability and entrainment. The quartz with different particle size had little impact on hematite recovery, but -45 μm fraction negatively affected Fe grade of concentrate both in the direct and reverse flotation of hematite. In the direct flotation, the Fe grade in froth product dropped off due to the fine quartz entrainment. While in the reverse flotation, the Fe grade in sink product dropped off as a result of difficulty in floating fine quartz particles, which was due to lower collision probability. Meanwhile, in the reverse flotation, the presence of hematite fines (-18 μm fraction) also had negative impact on hematite recovery because of fine particle entrainment.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 479-493
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of shear-induced breakage and reflocculation on the floc structure, settling, and dewatering of coal tailings
Autorzy:
Fan, Yuping
Ma, Xiaomin
Song, Shuai
Dong, Xianshu
Chen, Ruxia
Dong, Yingdi
Powiązania:
https://bibliotekanauki.pl/articles/110405.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal tailings
floc structure
shear
settling
dewatering
Opis:
Flocculation is crucial for the treatment of coal tailings in industries. In this paper, the effects of shear-induced breakage and reflocculation of the floc, settling, and dewatering of coal tailings were investigated. The results show that as shear strength increases, the settling velocity of flocculated tailings decreases. A shear rate of 200 rpm (170.6 s-1) leads to the loss of half the settling velocity. However, at high dosage cases, 200 rpm-300 rpm shear could improve the clarity of the supernatant. Small particles are flocculated preferentially, especially for particles below 10 µm. With the increase in dosage, the critical particle size for the occurrence of flocculation increases. The chaos index proposed can quantitatively reflect the degree of flocculation or reflocculation of coal tailings. At high dosage conditions, shear could enhance the dewatering performance of flocs by reconstructing the filter cake. Controlling the structure of flocs by dosage and shear strength can help obtain appropriate settling, clarifying, and dewatering performance of coal tailings.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 2; 363-373
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
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