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Tytuł:
Optimization of flotation efficiency of phosphate minerals in mine tailings using polymeric depressants : experiments and machine learning
Autorzy:
Alsafasfeh, Ashraf
Alagha, Lana
Alzidaneen, Ala
Nadendla, Venkata Sriram Siddhardh
Powiązania:
https://bibliotekanauki.pl/articles/2146912.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphate tailing
froth flotation
polymers
chitosan
artificial neural networks
Opis:
In this study, direct froth flotation experiments were conducted on silicate-rich phosphate tailing samples. The average grade of P2O5 in the flotation feed was 21.6% as determined using a combination of spectroscopic techniques including X-ray powder diffraction (XRD), mineral liberation analysis (MLA), and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Two polymers were selected to promote the depression of silicates and enhance the flotation of phosphates: in-house synthesized hybrid polyacrylamide (Hy-PAM) and chitosan. Flotation efficiency of phosphates was evaluated at different flotation conditions including depressant type, depressant dosage, pH, and the flotation time. Results indicated that the optimum flotation efficiency of phosphate minerals (84.6% recovery at 28.6% grade of P2O5) was obtained when Hy-PAM was utilized at the studied range of pH and flotation time. All datasets produced from the flotation experiments were integrated within the framework of machine learning (ML) using artificial neural networks (ANNs). The ANN platform was trained, validated, and successfully employed to predict the process outcomes in relation to the pulp and reagents characteristics, which in turn were used to determine the optimum values of process variables. Coefficient of determination (R2), mean absolute error (MAE), and root-mean-square error (RMSE) were used as model indicators. Optimization results showed that the peak flotation performance could be achieved at higher dosages of both polymers. However, lower pH and shorter flotation time for Hy-PAM, and higher pH and longer flotation time for chitosan, were predicted to give the optimum process efficiency.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 150477
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of the effect of operating parameters in column flotation using experimental design
Autorzy:
Bedekovic, G.
Powiązania:
https://bibliotekanauki.pl/articles/110943.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
froth flotation
column flotation
coal
experimental design
operating parameters
Opis:
The effect of air flow rate, pulp density and particle size was studied using central composite design for coal samples from the Lazy mine. Evaluation of column flotation tests was based on two dependant variables such as ash content and combustible matter recovery in the concentrate. The ash content in the concentrate was from 4.61 to 9.62% with the recovery of combustible matter from 17.43 to 81.98%. The ANOVA statistical analysis showed that the main effect of air flow rate has a significant impact on the combustible matter recovery and ash content in the concentrate. The main effect of pulp density on the combustible matter recovery is significant, whereas for the ash content it is not seen. There is a strong effect of the particle size on the ash content and combustible matter recovery in the concentrate. The interaction of the effect of the pulp density and particle size has a significant impact on the ash content in the concentrate.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 523-535
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of bubble load to interpret particle transport across the pulp-froth interface in a flotation cell
Autorzy:
Bhondayi, Clayton
Powiązania:
https://bibliotekanauki.pl/articles/1450066.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bubble loading
entrainment
true flotation
froth flow number
dropback
Opis:
This work demonstrates the use of bubble loads to understand the transport of particles across the pulp-froth interface in a flotation cell processing an Upper Group 2 chromitite seam (UG2) ore. Bubble loads were measured on the first primary cleaner cell of an operating flotation plant using a bubble load meter with a 20mm riser diameter. A bubble load value of 10.58grams/liter was obtained. The bubble load data was used to understand, entrainment and dropback of chromite as a function of particle size. By defining terms such as froth flow number and net dropback, it was found that chromite (known to be non-floatable) was also recovered through true flotation. The entrainment of chromite was found to be predominantly in -25 μm size while +25 μm size particles were found to be floatable and highly susceptible to dropping back. Net-dropback of chromite particles was found to increase with a decrease in chromite particle size contrary to expectation. An overall froth flow number of 69% was obtained.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 1; 54-64
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Processing of Magnesite Rich Flotation Waste Deposited on a Heap
Wzbogacanie odpadów bogatych w magnezyt zdeponowanych na składowisku
Autorzy:
Brezani, I.
Sisol, M.
Val'kova, M.
Marcin, M.
Powiązania:
https://bibliotekanauki.pl/articles/317850.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
flotacja odwrotna
surowiec wtórny
magnezyt
magnezyt ogniotrwały
reverse froth flotation
secondary raw material
magnesite
refractory magnesia
Opis:
Reverse froth flotation processing was used for beneficiation of magnesite rich material – tailings from processing of primary talc ore. This possible secondary magnesite ore, which contains over 40% MgO and 45,5% loss on ignition (LOI) is stored on a heap. Because of high content of impurities it cannot be directly used. Utilizable magnesite concentrate with 46% MgO, 49,4% LOI (1000°C) and content of SiO2 below 1,5% was prepared in single stage flotation at selected conditions. Yield of magnesite concentrate exceeding 69% could mean significant reduction in amount of stored material.
W procesie wzbogacania materiału bogatego w magnezyt wykorzystano odpady flotacyjne z wzbogacaniu talku zdeponowane na składowisku. Materiał magnezytowy będący materiałem wtórnym po wzbogacaniu talku zawierał ponad 40% MgO i 45,5% strat prażenia (LOI). Z powodu dużej zawartości zanieczyszczeń nie można go wykorzystać bezpośrednio. Koncentrat magnezytowy powinien charakteryzować się zawartością magnezu 46% MgO, stratami prażenia 49,4% LOI (1000°C) i zawartością SiO2 poniżej 1,5% . Wzbogacanie odpadów przeprowadzono metodą flotacji odwrotnej, jednoetapowo. Otrzymano uzysk koncentratu magnezytu przekraczający 69% co może oznaczać możliwość znacznego zmniejszenie ilości deponowanego materiału.
Źródło:
Inżynieria Mineralna; 2018, R. 19, nr 1, 1; 119-124
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Sodium Hexametaphosphate on Natural Flotation Kinetics of Talc Ore
Wpływ heksametafosforanu sodu na kinetykę flotacji naturalnej rudy talkowej
Autorzy:
Brezani, I.
Sisol, M.
Marcin, M.
Powiązania:
https://bibliotekanauki.pl/articles/318773.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
flotacja pianowa
flotowalność naturalna
depresor
kinetyka flotacji
ruda talku
froth flotation
natural floatability
flotation depressor
flotation kinetics
talc ore
Opis:
Ground high-grade ore with the d80 of 150 μm was subjected to a series of batch laboratory flotation tests, aimed at determining the natural flotation kinetics of talc mineral, using Methyl isobutyl carbinol (MIBC) frother as the only reagent. Classical first-order flotation model was used and the flotation kinetics are interpreted using the ultimate recovery (R∞) and flotation rate constant (k). Results are then compared with the kinetics of flotation in the presence of different dosages of the frother, Sodium hexametaphosphate (SHMP) and a mixture of SHMP and Soluble starch (SS) in various ratios. The design of experiment (DoE), evaluated using the Analysis of variance (ANOVA) test for multiple factors was used to calculate the statistical significance of the individual factors on the outcomes of the flotation tests – yield of the froth product, talc concentrate grade, talc recovery and flotation kinetics of both talc and gangue minerals. The effect of SHMP on the flotation kinetics of talc and gangue minerals in terms of affecting the R∞ and k parameters is here discussed in greater detail. Although both SHMP and SHMP/SS mixture was found to improve the overall grade of the talc concentrate, this was achieved at the expense of significantly lower recoveries of the valuable mineral.
Zmielona wysokowartościowa ruda o ziarnie podziałowym d80 = 150 μm została poddana serii laboratoryjnych prób flotacji, mających na celu określenie kinetyki flotacji naturalnej minerałów talku, w obec-ności jedynego środka zbierającego metylo-izobutylokarbinol (MIBC). Zastosowano klasyczny model flotacji pierwszego rzędu gdzie kinetykę flotacji interpretuje się za pomocą współczynnika uzysku R∞ i stałej szybkości flotacji (k). Wyniki porównano z kinetyką flotacji w obecności różnych dawek spieniacza, heksametafosforanu sodu (SHMP) i mieszaniny SHMP i rozpuszczalnej skrobi (SS) w różnych proporcjach. Plan eksperymentu (DoE), oceniono za pomocą analizy wariancji (ANOVA) dla wielu czynników użyto do obliczenia istotności statystycznej parametrów flotacji - wydajność produktu pianowego, zawartość talku, uzysk talku i kinetyka flotacji zarówno minerałów talku, jak i skały płonnej. Wpływ SHMP na kinetykę flotacji minerałów talku i skały płonnej na parametr R∞ i k są omówione bardziej szczegółowo. Chociaż stwierdzono, że dla obu mieszanek SHMP i SHMP / SS poprawie uległ stopień koncentracji talku odbyło się to jednak kosztem znacząco niższych wartości uzysku cennego minerału.
Źródło:
Inżynieria Mineralna; 2018, R. 19, nr 1, 1; 125-130
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proposition of a bubble-particle attachment model based on DLVO van der Waals and electric double layer interactions for froth flotation modelling
Autorzy:
Buchmann, Markus
Öktem, Gülce
Rudolph, Martin
Boogaart, K. Gerald van den
Powiązania:
https://bibliotekanauki.pl/articles/2146873.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
attachment
froth flotation
Hamaker constant
surfactants
collectors
hydrophobic interaction
Opis:
The attachment of bubbles and particles represents one of the sub-processes in froth flotation among others (e.g. collision and detachment). The main interactions present at short distances in such a bubble-particle system are the van der Waals and electrostatic double layer interactions combined in the DLVO theory. In this study, the special features of the attachment process were discussed with a focus on flotation. For the van der Waals interactions, the Hamaker constants were calculated with the help of Lifshitz´ macroscopic theory as a function of the separation distance for specific material combinations. A specific material system (PbS-Water-Air) was used to demonstrate the implementation of bubble-particle attachment of the proposed modelling framework. The effects of additional surfactant/collector and air layers on the solid interface were presented. This framework of layered systems showed that the sign of van der Waals interaction could be turned from repulsive to attractive without the need to extend the DLVO theory. The thickness of the layer as a function of collector adsorption between a particle and a bubble is suggested as a modelling parameter in bubble-particle attachment efficiency.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 154812
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection of the best route for column configuration in an existing copper circuit
Autorzy:
Can, N. Metin
Altun, Okan
Powiązania:
https://bibliotekanauki.pl/articles/109679.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
column flotation
sulphide ores
distribution of wash water
airflow rate
froth height
Opis:
This study was aimed to utilize column flotation to obtain much cleaner concentrate in the Cu circuit. However, the numbers of equipment and the proper streams for column application should be the key for successful operation. Therefore, the effects of some operational parameters such as wash water rate, airflow rate and froth height were investigated on the streams of namely Cu first cleaner concentrate, Cu rougher concentrate and Cu third cleaner concentrate in terms of mineral recoveries and selectivity. Distribution of wash water rate to products was also determined by a tracer test method. Optimum operating conditions and accordingly performance of the column were determined by simulation studies. According to the results, the suitable streams for industrial scale flotation column are advised as the rougher concentrate and/or first cleaner concentrate. With series installation of columns, it is possible to obtain two different concentrates which include 22% Cu, 4% Zn and 17% Cu, 8% Zn without any decrease in overall recovery of plant.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 552-564
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the foaming performance of ammonium dibutyl dithiophosphate on the flotation of slime-containing copper sulfide ore
Autorzy:
Deng, Rongdong
Duan, Wenting
Wang, Yi
Hu, Yuan
Powiązania:
https://bibliotekanauki.pl/articles/2175431.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ammonium dibutyl dithiophosphate
terpenic oil
foaming property
froth flotation
slime
Opis:
The use of ammonium dibutyl dithiophosphate (ADD) as a collector in the flotation of slimecontaining copper sulfide ore typically produces a sticky froth, which results in poor flotation. The mechanism and effects of copper sulfide ore flotation in synergistic systems comprising ADD and terpenic oil reagents have been systematically investigated to solve this problem. A high ratio of ADD to terpenic oil is not conducive to the flotation of fine-grained copper sulfide ores; however, adjusting this ratio may improve floatation by reducing the effect of the slime. Lowering the ratio from 5:1 to 1:1 increased the copper grade from 17.7% to 20.8%, while the recovery was largely unchanged. Notably, adjusting this ratio also reduced the cost of the flotation reagent. To study the mechanism by which the ADD–to–terpenic oil ratio affects the foam performance, the froth stability tests of the gas–liquid twophase and gas–liquid–solid three-phase systems were performed. Reducing the proportion of ADD reduced the froth water content and weakened the ability of the froth to collect gangue by adsorbtion with copper ions; this reduced gangue entrainment and maximized recovery and product quality.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 6; art. no. 153492
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of flotation reagents by normalization procedures
Autorzy:
Drzymala, J.
Powiązania:
https://bibliotekanauki.pl/articles/109804.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
separation
foam
froth
frother
selectivity
efficiency
normalization
generic reagents
selective reagents
internal parameter
external parameter
Opis:
Froth flotation is a dynamic multiphase process in which particulate matter is separated with the help of chemical reagents by gas bubbles immersed in water. The original flotation results are usually presented in the form of kinetic curves relating recovered particulate matter mass (yield ) or mass of a selected component (recovery ), both shortly denoted as y, versus process time t at different concentrations c (g/dm3) of the applied reagents. The kinetic curves can be modified into three: incentive (maximum yield or recovery ymax vs c), limits (ymax vs kinetic constant k or specific rate) and half-life of flotation (t1/2 vs c) curves. The original and modified curves can be normalized by taking into account either an external parameter such as molecular mass (MW), critical coalesce concentration (CCC), critical concentration at the minimum bubble velocity (CMV), dynamic foaming index (DFI), and many other parameters or an internal parameter such as time, concentration needed to achieve certain yield, recovery (y) or kinetic constant. Normalization leads to new flotation curves and provides additional useful information about flotation performance. Normalization can be fully effective, partial or ineffective. Normalization of the original flotation kinetic curves usually is ineffective. Also, normalization of the incentive curve with external parameters such as frother molecular mass, which changes reagent concentration from c (g/dm3) to C (mol/dm3), is also ineffective. Partially effective are normalizations with other external parameters such as CCC and CMV, usually within the same class of regents, for instance alcohols. Only DFI seems to be a universal external normalization parameter for flotation results because it provides fully effective normalization and thus predicts the flotation results. Limited data on DFI restrict a full verification of this hypothesis. Normalization of the modified flotation curves with internal parameters such as k50 (value of 1st order kinetic constant when recovery or yield is 50% after a given flotation time), Ct1/2 (frother concentration in mol/dm3 at which the flotation half-life has an arbitrarily chosen value) and cy75 (frother concentration in g/dm3 at which recovery or yield is 75% after a given flotation time) is a good base for practical classification of flotation reagents.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 182-192
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigating the effect of lip froth washing on coal yield during flotation of a high ash South African coal
Autorzy:
du Plessis, Cherryl
Sibanda, Vusumuzi
Dworzanowski, Marek
Danha, Gwiranai
Mamvura, Tirivaviri A.
Powiązania:
https://bibliotekanauki.pl/articles/2146887.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
mechanical flotation cell
flotation reagents
lip froth washing
coal yield
primary wash cells
secondary wash cells
Opis:
An investigation was conducted to evaluate the effect of lip washing on coal flotation at Anglo American’s Goedehoop South (GHS) fine coal plant in South Africa. In the test-work, performance of cells with lip washing system were compared with baseline cells without lip washing in terms of coal yield and coal quality. Yields observed with lip washing were significantly higher than those of baseline cells. Improvements of up to 15% were recorded. The product obtained at low flotation reagent dosages (1.30–1.45 kg/t) on lip wash cells had ~16.85% ash content against ~17.65% with baseline cells, suggesting that higher yields could be achieved at superior qualities to those achieved with baseline cells. At higher reagent dosages (1.60–1.75 kg/t), coal yields further improved but quality reduced on lip wash cells. Calorific Values (CV) of coal products obtained by lip washing and baseline flotation were similar. When different coal particle size fractions were floated separately, the yield increased as particle size increased from 75 to 300 μm and then decreased from 300 to 500 μm for both baseline and lip washing flotation. Lip washing caused a marked increase in the yield for finer particles (< 300 μm) with optimum size class of between 212 – 300 μm. In addition, a much bigger increase in the yield was achievable with lip washing of lower quality coal. The ash content after lip washing of poor-quality coal were also comparable to the ash content after lip washing of good quality coal.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 6; 169--181
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of single and mixed reagent systems on improved diaspore recovery
Autorzy:
Jiang, Hao
Xiang, Guoyuan
Gao, Ya
Khoso, Sultan Ahmed
Peng, Weiwen
Powiązania:
https://bibliotekanauki.pl/articles/110867.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
diaspore
flotation
mixed collector
froth stability
adsorption
Opis:
Frothing performance and stability of sodium oleate (NaOL) alone and in presence of methyl isobutyl methanol (MIBC), octanol (OCT) and polyethylene glycol (PEG) systems were studied and compared in order to enhance flotation separation of diasporic bauxite ore. Performance of a single (NaOL) and mixed systems (NaOL-MIBC, NaOL-OCT, NaOL-PEG) was evaluated through flotation tests, three-phase dynamic froth stability tests, zeta potential measurements and adsorption analysis. The mixed systems showed a stable froth and an improved recovery with their descending order NaOLPEG˃NaOL-OCT ˃ NaOL-MIBC. Adsorption analysis and zeta potential measurements suggested that, except NaOL adsorption, there was no significant co-adsorption of alcohols on the diaspore surface. However, adsorbed amount of NaOL on the diaspore surface was extremely high; accounts for more than 90% of the total substance used in the pulp.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1179-1191
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acidified water glass in the selective flotation of scheelite from calcite, Part I: performance and impact of the acid type
Autorzy:
Kupka, Nathalie
Möckel, Robert
Rudolph, Martin
Powiązania:
https://bibliotekanauki.pl/articles/109345.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
acidified water glass
scheelite calcite separation
froth flotation
Opis:
To improve the performance of sodium silicate in scheelite flotation and allow the selective separation of scheelite from other semi-soluble salt-type minerals such as calcite, three acids, sulfuric, oxalic and for the first time hydrochloric are used to acidify sodium silicate (also called water glass). A literature review of previous usage of acidified water glass shows that no comparison between acids was made before, that comparisons with alkaline water glass were limited and that the idea that acidified water glass is more efficient at lower dosages has not been proven in scheelite flotation. As a consequence, the impact of the acid type, the ratio between acid and sodium silicate and acid dosage is tested in single mineral flotation and batch flotation experiments. All three acids allow a higher performance of acidified water glass compared to alkaline water glass at lower dosages and with little addition of acid: the tungsten recovery and grade are improved while silicates and to a lesser extent calcium-bearing minerals float less. The dosage of acid is less determining than the mass ratio of the acid to sodium silicate, except in the case of hydrochloric acid. Overall, the acid type does not matter as all three acids perform well in flotation, whereby oxalic and hydrochloric acid are better.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 2; 238-251
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acidified water glass in the selective flotation of scheelite from calcite, part II: species in solution and related mechanism of the depressant
Autorzy:
Kupka, Nathalie
Kaden, Peter
Jantschke, Anne
Schach, Edgar
Rudolph, Martin
Powiązania:
https://bibliotekanauki.pl/articles/1845224.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
acidified water glass
scheelite calcite separation
froth flotation
mechanism
Opis:
Sodium silicate is one of the main depressants against calcite and fluorite in the scheelite flotation industry. In the first part of this article, the authors acidified sodium silicate (AWG) with three acids (sulfuric, oxalic and hydrochloric) to improve its performance. Results showed that acidified water glass outperforms alkaline water glass in terms of selectivity: it increases mainly the grade by further depressing silicates and calcium-bearing minerals. In most cases, AWG requires lower dosages to do so. The effect of acidified water glass is evaluated through Mineral Liberation Analysis (MLA), froth analysis, Raman and Nuclear Magnetic Resonance (NMR) spectroscopy in order to hypothesize its mechanism. MLA shows that AWG affects silicates and sulfides more intensely than semi-soluble salttype minerals. Froth observations indicate other species in solution associated to the acid having an impact on the flotation results. Raman spectroscopy and NMR measurements indicate that the solution undergoes deep depolymerization when water glass is acidified. Lower molecular weight silica species, specifically Si-O monomers such as SiO(OH)3- will be responsible for the depression of the gangue minerals and are the drivers of the selectivity of AWG, more than orthosilicic acid. Depolymerization is more or less effective depending on the mass ratio of the acid to water glass and depending on the acid.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 797-817
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of seawater main components on frothability in the flotation of Cu-Mo sulfide ore
Autorzy:
Laskowski, J. S.
Castro, S.
Ramos, O.
Powiązania:
https://bibliotekanauki.pl/articles/109747.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
seawater
froth stability
Cu-Mo flotation
magnesium ions
molybdenite flotation
Opis:
The main problem in the flotation of Cu-Mo sulfide ores in seawater is poor floatability of molybdenite at pH>9.5. Froth stability plays a very important role in determining concentrate grade and recovery in flotation operations and in this paper both floatability and frothability have been tested. The frothability have been studied by measuring froth equilibrium layer thickness in a modified laboratory flotation cell. Two chemical aspects of seawater need to be considered: the content of NaCl (around 87% of salinity), and the concentration of secondary ions (around 13%) (sulfate, magnesium, calcium, bicarbonate ions, etc.). Seawater, NaCl solutions, and seawater’s ions were found to depress frothability. The effect of pH on frothability over the pH range from 9.5 to 11, which is very strong in freshwater, becomes negligible in seawater and the tested electrolyte solutions. The analysis of the relationship between the mechanisms of molybdenite depression and the loss of frothability in seawater implies that the effects of the studied ions on molybdenite floatability and on pulp frothability are different. While depression of molybdenite floatability could be tracked down to magnesium hydroxide precipitation as a main culprit, the depression of frothability is a much more complicated issue.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 17-29
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of enargite from complex copper concentrates by selective surface oxidation
Autorzy:
Li, Tangfei
Zhang, Yansheng
Zhang, Bo
Jiao, Fen
Qin, Wenqing
Powiązania:
https://bibliotekanauki.pl/articles/110698.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mineralogy
enargite
selective surface oxidation
froth flotation
EDTA extraction
Opis:
In previous study, the promising results of separating enargite from non-arsenic copper sulfides were obtained using selective surface oxidation in pure mineral systems. However, this technology was not well understood in real ores or concentrates. In this study, the flotation separation of enargite from complex copper concentrates by selective surface oxidation was investigated. The effects of regrinding, pulp pH, NaClO concentration, conditioning time and flotation time on separation of enargite from NECu minerals were studied. The mineralogical characteristics of the flotation feed and products were showed as an instructive tool to understand the separation results. According to the results of EDTA extraction, the possible mechanism for separation of enargite from NECu minerals is that enargite is more resistant to oxidized compared to NECu minerals. The following order for the oxidation of NECu minerals and enargite is obtained: chalcopyrite (chalcocite, digenite)> enargite (covellite).
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 4; 852-864
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 32

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