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Wyszukujesz frazę "Zhang, J" wg kryterium: Autor


Wyświetlanie 1-12 z 12
Tytuł:
Experimental investigation of a high temperature resistant and low friction fracturing fluid
Autorzy:
Xiao, B.
Zhang, S.
Zhang, J.
Hou, T.
Guo, T.
Powiązania:
https://bibliotekanauki.pl/articles/109339.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high temperature fracturing fluid
resistance to shearing
hydroxypropyl guar
low friction
delayed crosslinking
Opis:
The performance of a hydraulic fracturing fluid (HFF) system directly determines the efficiency of stimulation. Since the targeted formations of most oil fields in China are characterized by large depth (~5000 m), high temperature (160 to 180 °C) and tight lithology, newer and suitable HFFs have to be developed. Based on a newly synthetized organo-boron/-zirconium cross-linking agent (Gh-g), a composite temperature stabilizer (WJ-6) and other optimized additives via indoor evaluation, this study introduced a novel HFF, which is thermally stable at high temperature (HT) up to 180 °C and exerted low friction pressures. The performance of HFF was evaluated in the laboratory. The experimental results showed that the HFF system performed well at HTs. It maintained a viscosity of 100 mPa•s or more after 90 min of shearing (170 s−1) at 180 °C. Furthermore, the system exhibited delayed cross-linking. It took 120 s for the cross-linking reaction to complete; therefore, the tube friction was reduced to a large extent. Another characteristic feature of the formulated HFF system was the low friction pressures, where the drag reduction percentage was in the range from 35% to 70%. Moreover, only minor damage was caused by the fluid to the formation core samples. The average core permeability damage was 19.6%. All these qualities ensure that this fluid system is in full compliance with the requirements of the fracturing treatment.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 1; 37-47
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation behaviour and surface characteristic of anosovite in a sodium oleate solution
Autorzy:
Wang, Y.
Wen, S.
Zhang, J.
Wu, D.
Xian, Y.
Shen, H.
Powiązania:
https://bibliotekanauki.pl/articles/110766.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
anosovite
sodium oleate
flotation
adsorption
Opis:
Properties of anosovite in titanium slag, anosovite flotation response in a collector solution of sodium oleate, and adsorption behaviour of sodium oleate on the mineral surface were studied in the present work using XRD, Raman spectra, flotation tests, zeta potential analysis, FTIR and XPS. The results show that the anosovite crystal contains magnesium, and its chemical composition is Mg0.09Ti2.91O5. The chemical bonds on the anosovite surface mainly comprise Ti-O bonds. Micro-flotation tests indicate that anosovite has better floatability at a wide pH range and the recovery reaches 88% at pH=6, when the dosage of sodium oleate is only 4·10−6 mol/dm3. The point of zero charge of anosovite was determined near pH 3.2 by the zeta potential measurement. In the flotation process, chemical adsorption occurs between the carboxyl of sodium oleate and the titanium sites on the anosovite surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 714-723
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contribution on fluid inclusion abundance to activation of quartz flotation
Autorzy:
Yuan, Y.
Zhang, L.
Guan, J.
Zhang, C.
Wu, J.
Chen, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110067.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
recovery
flotation
mineralogy
fluid Inclusions
fluid inclusion abundance
Opis:
In this study, comparative experiments were conducted on the recovery of quartz using flotation with different fluid inclusion abundances. A large number of fluid inclusions with various sizes have been found in natural quartz. Micrographs, inductively coupled plasma, electron probe microanalysis, homogenization temperature, Raman spectra, zeta potentials, X-ray photoelectron spectroscopy, scanning electron microscope, and energy dispersive spectrometer were used to characterize the fluid inclusions and quartz, as well as the adsorption tests and single mineral flotation experiments to investigate its floatability. The results demonstrated that it was more likely for quartz with higher fluid inclusion abundance to connect with Fe3+ sufficiently to achieve a high level of flotation recovery, due to the powerful collecting ability by sodium dodecyl sulphonate to Fe3+. Furthermore, the mechanism indicated that the adsorption between quartz and Fe3+ was a process of chemisorption.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 981-991
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface probability model for estimation of size distribution on a conveyor belt
Autorzy:
Zhang, Z
Yang, J.
Dou, D.
Powiązania:
https://bibliotekanauki.pl/articles/109982.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
size distribution
surface probability model
conveyor belt
particles
Opis:
Estimation of size distribution by image analysis is a key issue in mineral engineering. However, only the surface information of ore piles can be captured, which is a headache problem in this field while only a few researchers pay attention to this problem. A new surface probability model was proposed for estimation of size distribution on a conveyor belt based on the Chavez Model in this investigation. This model was tested and verified to have smaller errors in single size fraction but have bigger errors in multiple size fractions. Several error trends were found and a correction factor was introduced to correct the higher errors. A series of linear equations were developed to calculate this specific correction factor according to Dm (average particle size) and the height of pile. Therefore, empirical probability can be estimated by the specific correction factor and calculated probability, and the surface information of ore piles can be converted into the global information of piles.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 2; 591-606
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pre-concentration of vanadium-bearing mica from stone coal by roasting-flotation
Autorzy:
Tang, J.
Zhang, Y.
Bao, S.
Liu, C.
Powiązania:
https://bibliotekanauki.pl/articles/109373.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
roasting
flotation
vanadium bearing mica
stone coal
Opis:
In China, stone coal is an important source of vanadium. The use of roasting–floatation for the pre-concentration of vanadium bearing mica from vanadium bearing stone coal was investigated based on its mineralogical characteristics. The results showed that the vanadium occurred in mica minerals and the main gangue minerals were coal, calcite, and quartz. The pre-concentration process comprises three key steps: roasting, desliming, and flotation. The coal was completely removed by roasting at 700 °C for an hour. Slime was concentrated and the subsequent flotation pulp was improved by desliming. Calcite was removed by reverse flotation and mica was concentrated by positive floatation. During the process, the grade of V2O5 was increased from 0.71% to 1.14%, and 46.18% of the tailings were rejected. The leaching rate of vanadium was increased from 30.49% of raw ore to 69.15% of the concentrate which was an increase of about 40% at the same leaching process. This technique may promote the efficient utilization of stone coal resources.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 402-412
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of large particle sizes using a machine vision system
Autorzy:
Zhang, Z.
Yang, J.
Su, X.
Ding, L.
Powiązania:
https://bibliotekanauki.pl/articles/109404.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
machine vision
particle size distribution
equivalent ellipse
best-fit rectangle
representing analysis
Opis:
Many methods based on machine vision were used to estimate coarse particles size distribution in recent years, but comparison of accuracy parameters representing particle size has not been carried out and a related representing analysis has not been yet proposed. Nine parameters were investigated. The results indicated the minor axis of equivalent ellipse and breadth of the best-fit rectangle were the most suitable for representing particle size. The former accuracy ratio was 86.43% and the latter accuracy ratio was 85.39%, while the accuracy of other parameters was less than 70%. A related representing analysis was proposed to explain this phenomenon. This research is instructive and meaningful for the size distribution estimation by machine vision.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 397-405
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of dissolved mineral species in quartz flotation and siderite solubility simulation
Autorzy:
Luo, X.
Wang, Y.
Ma, M.
Song, S.
Zhang, Y.
Deng, J.
Liu, J.
Powiązania:
https://bibliotekanauki.pl/articles/109459.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
solubility
siderite
calcium ion
temperature
flotation
Opis:
Quartz is, in most cases, the major gangue mineral found in the iron ores. Although it can be activated by calcium at strong alkaline pH, quartz nevertheless, reports to the concentrate with Fe when the iron ores contain siderite. It causes a poor concentrate grade and separation between quartz and iron minerals. The effect of siderite on reverse anionic flotation of quartz from hematite was studied in our previous investigations. In this work, the effect of siderite dissolution on the quartz recovery in the froth product and the effect of pH, ions and temperature on siderite dissolution were investigated. Microflotation, PHREEQC simulation, solution chemistry calculation and Fourier transform infrared spectroscopy (FTIR) measurements were conducted. It was observed that the dissolved species of siderite exhibited negative impact on quartz flotation. This influence became weak to some extent by either stripping the dissolved species or shortening dissolution time. Siderite was easily dissolved in the presence of calcium ion under strong alkaline conditions and its solubility increased with increasing the calcium ion concentrate and temperature. When the calcium ion was added as an activator of quartz under strong alkaline conditions (pH>9.96), calcium existed mainly in the CaCO3 precipitation form according to the solubility rule in the presence of siderite. This form could adsorb onto quartz surfaces and further the chemical reaction between starch and quartz was monitored by FTIR measurements. This study provides a further supplement for previous study. A potential strategy is suggested that finding a collector used at low temperature or flotation under neutral (or weak alkaline) medium is helpful to the reverse flotation of iron ores containing siderite.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1241-1254
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One step purification of impurities in the leachate of weathered crust elution-deposited rare earth ores
Autorzy:
Zhou, F.
Feng, J.
Wang, Z.
Xu, Y.
Zhang, Z.
Chi, R.
Powiązania:
https://bibliotekanauki.pl/articles/110333.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
leachate
weathered crust
rare earth ore
leachate purification
precipitation
Opis:
It is necessary to control and reduce the high content of Al3+, Cu2+ and Pb2+ ions in the leachate of weathered crust elution-deposited rare earth ore to facilitate the rare earth recovery and the quality of rare earth products. Neither NH4HCO3 nor Na2S are suitable for removal of all impurity ions and meanwhile maintain high rare earth recovery. Conventionally, NH4HCO3 is firstly adopted to remove Al3+, and then Cu2+ and Pb2+ are removed by using Na2S. This two steps purification process is quite long and results in lots of complication in operation. In this paper, a one-step purification by using the compound of NH4HCO3 and Na2S was proposed to remove Al3+, Cu2+ and Pb2+. The results showed that after purification 89% Cu, 92% Pb and 74% Al were removed from the leachate solution by using 0.1 M compound of NH4HCO3/Na2S, while maintaining 89% rare earth. The optimal purification parameters were: volume ratio of NH4HCO3 to Na2S of 9:1, volume ratio of compound to leachate of 0.05:1, precipitation time of 30 min.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1188-1199
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:
Pre-concentration of graphite and LiCoO2 in spent lithium-ion batteries using enhanced gravity concentrator
Autorzy:
Zhu, X,-N.
Tao, Y.-J.
He, Y.-Q.
Zhang, Y.
Sun, Q.-X.
Powiązania:
https://bibliotekanauki.pl/articles/109609.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
spent lithium-ion batteries
electrode material
resource utilization
pre-concentration
enhanced gravity concentrator
Opis:
The pre-concentration of electrode material of spent lithium-ion battery has great significance on the resource utilization and environmental protection. The feasibility of separation of graphite and LiCoO2 based on density difference using the enhanced gravity concentrator was verified in this paper. Combustion characteristics of LiCoO2 and graphite were used to propose a simple evaluation index of separation efficiency. Separation tests were carried out to specify the influence of operating parameters on the separation efficiency. Moreover, the effect of particle size on the separation performance was studied. Combustion characteristics results showed that mass loss of graphite was much greater than that of LiCoO2. Thus, mass loss were used to evaluate the purity of product. Effective separation of graphite and LiCoO2 was achieved by the enhanced centrifugal separator. Separation results showed that increasing centrifugal force decreased the overflow yield and increased the graphite content of the overflow stream. In addition, yield of overflow grew an increase in fluidization water pressure, while the purity of graphite in overflow decreased. The effect of particle size on the separation efficiency was also significant, the separation efficiency decreased with the decreasing of particle size.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 293-299
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of float-sink and progressive release flotation of ground products of coal middlings
Autorzy:
Xie, W.
He, Y.
Luo, C.
Zhang, X.
Li, H.
Yu, J.
Wang, H.
Shi, F.
Powiązania:
https://bibliotekanauki.pl/articles/109500.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal middlings
float-sink
progressive release flotation
XPS
EDX
Opis:
An additional recovery of coking coal middlings can be utilized for increasing of the concentrate yield of coking coal. A combined flow sheet of comminution and flotation can realize this target. To investigate the effect of grinding process on further flotation of ground products, progressive release flotation tests were used to compare with the float-sink tests, which were regarded as a criterion. Coal middlings were ground by wet-milling with iron balls to <0.5 mm. Curves of ash vs. cumulative yields of sized products indicated that the concentrate yield of coal separated by progressive release flotation was lower than that of coal benefited by the float-sink test, with the same ash for four size fractions (0.5-0.25 mm, 0.25-0.125 mm, 0.125-0.074 mm and <0.074 mm). Distributions of elements conducted by energy disperse spectroscopy (EDX) showed that associated kaolinite was liberated and exposed on the surface. It led to the shift of local surface property from hydrophobicity to hydrophilicity. Meanwhile, analyses of chemical property performed by an X-Ray photoelectron spectrometer (XPS) depicted that the hydrophilic mineral FeOOH, which generated in the grinding process, was adsorbed on the coal surface. Flotation of the ground products were worsened due to the increase of hydrophilicity of the coal surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 675-684
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of polyacrylic acid on the surface properties of calcite and fluorite aiming at their selective flotation
Autorzy:
Zhang, C.
Gao, Z.
Hu, Y.
Sun, W.
Tang, H.
Yin, Z.
He, J.
Guan, Q.
Zhu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/110577.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
calcite
fluorite
selective flotation
polyacrylic acid
Opis:
In this study, the polyacrylic acid (PAA) was studied as a selective depressant for calcite in the selective flotation of fluorite and calcite, and the implications of this process for the separation of fluorite ore were studied using micro-flotation tests, and the results were analyzed with Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. The flotation tests indicated that the preferential adsorption of PAA onto calcite rather than sodium oleate (NaOl) could selectively depress the flotation of calcite, allowing its separation from fluorite at pH 7. The zeta potential of calcite became more negative with the addition of PAA rather than with NaOl. However, the characteristic features of PAA adsorption were not observed for fluorite, suggesting that NaOl preferentially adsorbed on the surface of fluorite, or that PAA could be replaced by NaOl on the fluorite surface. FT-IR and XPS analysis were utilized to obtain a better understanding of the mechanism by which PAA was more strongly adsorbed on the calcite surface than NaOl. This was revealed to occur through chemical bonding between the carboxyl group of PAA and the hydroxyl groups of the Ca species on the calcite surface, modifying the structure of the adsorbed layer. A possible adsorption mechanism, along with a postulated adsorption mode for the surface interaction between PAA and calcite, is proposed.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 868-877
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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