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Wyszukujesz frazę "flotation kinetics" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
Surface roughness in bubble attachment and flotation of highly hydrophobic solids in presence of frother – experiment and simulations
Autorzy:
Kosior, D.
Kowalczuk, P. B.
Zawala, J.
Powiązania:
https://bibliotekanauki.pl/articles/109319.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
surface roughness
attachment
flotation
kinetics
frother
Opis:
In this paper, the kinetic of the three-phase contact (TPC) formation and the flotation recovery of highly hydrophobic solids with different surface roughness were studied in pure water and aqueous solutions of n-octanol. The surface roughness varied between 1 to 100 μm. It was found that there was a strong influence of surface roughness on both kinetics of TPC formation and flotation. The time of three phase contact formation and flotation rate were much faster for rough surfaces in both water and aqueous solutions of frother. Irrespective of the surface roughness, at above a certain frother dose, the attachment time increased and the flotation rate decreased. It was related to the presence of air at the hydrophobic solid surfaces. The mechanism of this prolongation of the time of TPC formation at the solid surfaces with different roughness due to the frother overdosage was discussed, and the experimental data were confirmed by numerical simulations.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 63-72
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekologiczne aspekty związane z efektami wysokociśnieniowego rozdrabniania w prasach walcowych
Environmental Aspects Connected with Effects of High-pressure Comminution in Roller Presses
Autorzy:
Saramak, D.
Tumidajski, T.
Gawenda, T.
Naziemiec, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1819049.pdf
Data publikacji:
2013
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
ekologiczne aspekty
prasy walcowe
models
flotation
kinetics
Opis:
The aim of the paper is an analysis of work effects of HPGR-based technological circuits in industrial mineral processing operations. High-pressure grinding rolls technology is currently one of the most effective methods of raw materials comminution both from the scope of the crushing products quality as well as the environmental effects associated with a lower environmental nuisance. In the first part of investigations the effective control of the particle size distribution of crushing products through the proper selection of operating pressure in the press. In the next stage the HPGR products were ground in a ball mill. The results showed that the grinding efficiency at higher values of operating pressure is greater, it was also observed a rapid increase in yield of the fine particle fractions, which can be directed to initial flotation operations. In the next stage, a methodological assumptions for optimization of a multi-stage comminution circuit were presented. In order to optimize the work effects of circuit the feed preparation manner for each stage of crushing should be taken into consideration. Another aspects which should not be missed are the crushing and grinding devices operating conditions (the relationship between the feed properties and the construction and operating parameters of the device) and characteristics of obtained products.
Źródło:
Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 2; 1580-1593
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physicochemical study of dye removal using electro-coagulation-flotation process
Autorzy:
El-Hosiny, F. I.
Abdel-Khalek, M. A.
Selim, K. A.
Osama, I.
Powiązania:
https://bibliotekanauki.pl/articles/109865.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
electro-flotation
electrocoagulation
dyes
wastewater
kinetics
thermodynamics
Opis:
The performance of electro-flotation with aluminum electrodes for the removal of different dyes from synthetic aqueous solutions and real wastewater was studied. Parameters affecting the electro-coagulation-flotation process, such as pH, initial dye concentration, treatment time and temperature were investigated. The maximum dye removal from synthetic solutions was achieved at pH 7. The order of the dye removals is nonionic>cationic>anionic. The removal process follows pseudo first-order kinetics and the adsorption follows both physical and chemical adsorptions which is exothermic. Negative values of entropy change, ΔS°, and Gibbs free energy change, ΔG°, indicate that this adsorption process is spontaneous and less favorable at high temperatures. Treatment of a real wastewater from textile dyeing factory showed that the removal efficiency was ranging between 92-99% for all constituents. The energy consumption is 0.0167 kWh/dm3.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 321-333
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lignite cleaning in NaCl solutions by the reverse flotation technique
Autorzy:
Zhang, H.
Liu, Q.
Powiązania:
https://bibliotekanauki.pl/articles/110516.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
lignite
reverse flotation
NaCl
kinetics
coal preparation
Opis:
A cleaning possibility of low (BD) and high ash content (IM) lignites in NaCl solutions using a reverse flotation technique was studied. Preliminary test results indicated that BD lignite cannot be cleaned effectively in the traditional manner because gangue was floated first rather than a combustible material. Further studies indicated that the lignite cleaning in NaCl solutions using the reverse flotation technique is possible. However, a large quantity of dodecyl amine hydrochloride (DAH) was required. A lower ash content in a concentrate can be obtained by addition of NaCl. A concentrate yield can be im-proved by addition of starch. Under the test conditions, for BD lignite with the ash content in the feed 15.19%, the ash content in the concentrate 11.44% and the concentrate yield 67.38% were obtained. Similarly, for IM lignite with the ash content in the feed 57.40%, the ash content in the concentrate 32.90% and the concentrate yield 25.08% were obtained. The flotation rate constant k and maximum ash recovery ε∞ significantly increased with the NaCl concentration.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 695-706
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic separation curves based on process rate considerations
Autorzy:
Drzymala, J.
Ratajczak, T.
Kowalczuk, P. B.
Powiązania:
https://bibliotekanauki.pl/articles/110027.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
separation
flotation
kinetics
separation curves
process rate
Opis:
There are many graphical representations of separation results involving time as a crucial parameter determining the kinetics of a process. The graphical representations of results of separation are usually in the form of 2D plots relating two parameters which one of them is time. Time can also be utilized as a complex parameter such as a process rate. The plots involving time are called kinetic curves. Theoretically, the number of kinetic curves is infinite. The basic process kinetic curves, relating either yield (or recovery) and time can be modified to obtain numerous local and global efficiency curves. The global efficiency kinetic curves provide characteristic constants which do not change with the time and yield of a process. In this paper the local and global efficiency plots were created using experimental data which followed the so-called first order kinetics. It was shown that the integral 1st order kinetic equation provided the kinetic constant k which was numerically identical with the 1st order specific rate v, while their units were different (k, 1/min; v, %/(%·min). The global efficiency parameters plotted versus the maximum yield provided another type of plot, which can be called the limits kinetic curve. The limits kinetic curves are very useful for characterizing, quantification and classification of separation systems. The limits kinetic curves can be normalized providing one universal curve with a characteristic point, for instance, v50 indicating the specific rate (or kinetic) constant at the maximum recovery equal to 50%. The mathematical equation of the normalized limits kinetic curve was given in the paper.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 983-995
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient chromium removal from aqueous solutions by precipitate flotation using rhamnolipid biosurfactants
Autorzy:
Shojaei, V.
Khoshdast, H.
Powiązania:
https://bibliotekanauki.pl/articles/110347.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kinetics
wastewater
chromium
rhamnolipid biosurfactant
precipitate flotation
Opis:
In the present research study, the efficient removal of hexavalent chromium from aqueous solutions by precipitate flotation method was investigated. The experiments were carried out with the use of ferrous sulfate as a precipitating agent for chromium and rhamnolipid bio surfactant (RL) as a precipitate collector. The effects of rhamnolipid and co-precipitate concentrations, aeration rate, solution pH, and salt addition on the chromium removal were studied using a full factorial design. The chromium removal and water recovery to foam products were analyzed as process responses. Statistical analyses showed that the effects of all factors on the chromium removal followed a non-linear trend with a peak at the middle level. After the process optimization, the maximum chromium removal of 96.75±0.3% was obtained at pH value of 8, RL/Cr ratio of 0.01, Fe/Cr ratio of 3, and aeration rate of 50 cm3/min. Addition of salt with different cationic and anionic groups negatively influenced the removal efficiency. Kinetic studies suggested that the process of chromium removal by the precipitate flotation followed the first-order process with a rate constant of about 0.018 sec-1. Given the good removal capacity and kinetics, rhamnolipid biosurfactants can be a promising environmental-friendly bio collector for the removal of chromium ions from aqueous solutions.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 1014-1025
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic modelling of flotation column and Jameson cell in coal
Autorzy:
Karaca, Sevgi
Ucar, Ali
Sahbaz, Oktay
Powiązania:
https://bibliotekanauki.pl/articles/2146872.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coarse particle
flotation column
Jameson cell
kinetics
particle size
Opis:
Physical enrichment technologies can be used worldwide in various coal washing plants to enrich up to 500 μm particle size. Conversely, coals smaller than this are discarded as waste, causing storage and environmental issues. In this regard, studies on coal below 500 μm in Turkey have recently acquired attraction. The Jameson flotation cell and flotation column, which have many uses worldwide but are not used throughout the plant in Turkey, were used to investigate the separation possibilities of coals below 500 μm. In the study, the flotation column and Jameson cell performances for three different particle sizes (-500+300, -300+212 and -212+106 μm) were compared. For the first time, both machines operated in a negative bias condition. In addition, the flotation kinetics of the machines were modelled with some critical operating parameters. Models illustrating the main and multiple effects of the parameters were developed using the data derived from the experimental results, and the models were statistically significant at the 95% confidence level. In the experiments performed with both flotation machines, the flotation rate increases with the decrease in particle size in general. According to the results, the velocity increase in the Jameson cell was 0.0050-0.0075 min-1 compared to the flotation column in the experiments performed in the size range of -500+300 μm, and the flotation rate constant increased approximately twice. In the size range of -212+106 μm, the difference became larger, and the flotation rate of the Jameson cell increased up to six times with a difference of 0.0450-0.0500 min-1.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 152848
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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