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1

Flotation performance of a novel collector, ethyl o-mesitylsulfonylacetohydroxamate, for bastnaesite ores

Di Yuli, Liu Xiankui, He Xia, Zhang Hao, Huang Haiyan, Cheng Wang, Jiao Yu

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 1

art. no. 185550

EN

Existing collectors used in the flotation process of bastnaesite ores are characterized by the poor flotation performance and low recovery. In this paper, from the perspective of molecular structure, ethyl O-mesitylsulfonylacetohydroxamate (C1) was selected as a novel collector for bastnaesite ores, and compared with the most commonly used collector, salicylhydroxamic acid (C2), in the flotation test with bastnaesite ore with fine mineral particles, complex embedding and a high mud content. The flotation test confirmed that C1 had the better collection ability and flotation performance than C2. Then, the adsorption mechanisms between collectors (C1 and C2) and bastnaesite surface were explored based on first principles thinking. The adsorption energies between collectors (C1 and C2) and the (110) plane of bastnaesite were respectively calculated as -1.79 eV and -1.44 eV and corresponding adsorption heights were respectively 1.65 Å and 2.43 Å. These data indicated that C1 had the better affinity to the (110) plane of bastnaesite and the better binding. The calculation results of partial density of states (PDOS) showed that both collectors underwent significant orbital hybridization with the (110) plane of bastnaesite, suggesting strong electronic interactions.

2

Metallurgical evaluation of copper ore flotation performance in the presence of Rhamnolipid biosurfactant produced from Pseudomonas aeruginosa. Part 1: Copper-bearing minerals

Biniaz Gholamreza, Khoshdast Hamid, Garmsiri Mohammad Reza, Maleki-Moghaddam Mostafa, Hassanzadeh Ahmad

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 183176

EN

The present research work studies the effect of rhamnolipid biosurfactant (RL) produced from Pseudomonas aeruginosa bacteria on the metallurgical response of a copper ore sample flotation through an extensive full factorial experimental design. Key influential factors including feed particle size, pulp solid content, pH, and dosages of collector, frother and RL biosurfactant were considered. The surface activity of the RL biosurfactant was also studied based on a D-optimal experimental design. Surface activity results revealed that increasing pH and electrolyte concentrations negatively impacted the RL surface activity, while the effect of electrolyte source was dependent on their ionic strength. Metallurgical investigations showed that operating parameters significantly influence the copper grade and recovery with considerable interaction among various parameters. RL biosurfactant was found to negatively decrease the copper grade (~0.5%) and positively enhance the recovery (~3%). Effect of RL was attributed to two potential mechanisms, i.e., being ineffective on copper minerals and/or interaction with gangue minerals, as well as increasing the rate of entrainment due to high foamability, both of which increased non-selective recovery of gangue minerals. Interestingly, regardless of the structural similarities, no interaction between the flotation reagents and rhamnolipid was observed. Fourier-transform infrared (FTIR) spectroscopic analysis of copper minerals, both pure and RL-exposed, showed that there was actually no molecular interaction between RL molecules and particle surface.

3

Surface Energy of Solids: Selection of Effective Substrates for Bioadhesion in Aqueous Media

Boniewicz-Szmyt Katarzyna, Pogorzelski Stanisław

Scientific Journal of Gdynia Maritime University

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2019

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nr 112

7--22

EN

Surface wettability of model solids of different hydrophobicity (from hydrophilic to hydrophobic) in contact with an aqueous medium was determined by measuring the dynamic contact angles (CA) using common techniques: sessile drop, inclined plate and captive bubble. The surface wettability energetics parameters: contact angle hysteresis (CAH), 2D adhesive layer pressure, surface free energy (SFE) and work values of cohesion, adhesion and spreading were determined using the formalism proposed by Chibowski [2003]. CA values depended on the technique used and experimental conditions (flow numbers, spatial heterogeneity and roughness of the sample). The most effective substrates for testing bioadhesion on solids submerged in aqueous media were hydrophilic surfaces (SFE ~ 40–58 mJ m-2; CAH ~ 16–20 mN m-1).

4

On the interpretation of the xps spectra of adsorbed layers of flotation collectors - ethyl xanthate on metallic lead

Nowak P., Laajalehto K.

Physicochemical Problems of Mineral Processing

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2007

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Vol. 41

107-116

EN

Ethyl xanthate adsorption on metallic lead was studied by X-ray photoelectron spectroscopy (XPS) after treatment of lead sample at different potentials in aqueous NaNO3 solutions containing ethyl xanthate. Continuous increase of the amount of ethyl xanthate species on the lead surface was observed as the potential was raised from - 400 mV to - 340 mV at the ethyl xanthate concentration of 10-4 M. At the potential of –400 mV and the concentration of 10-4 M the amount of xanthate at the surface was at the detection limit. Lead oxide and lead carbonate were found as the main oxidation products of metallic lead. Ethyl xanthate layer was found to decompose to sulfide like species in a few hours of excitation with monochromatic AlKa radiation, if XPS measurement was done at room temperature. Cooling the sample with liquid nitrogen down to T ≈ 130 K prevented the decomposition.

PL

Adsorpcję ksantogenianu etylowego na powierzchni metalicznego ołowiu z roztworów wodnych NaNO3 badano metodą spektrometrii fotoelektronów generowanych promieniowaniem rentgenowskim (XPS, ESCA). W roztworze ksantogenianu o stężeniu 10-4 mol dm-3, wraz ze wzrostem potencjału od wartości -400 mV do - 340 mV (względem standardowej elektrody wodorowej), ilość ksantogenianu na powierzchni wrasta od wartości znikomo małej (na pograniczu możliwości detekcji) do pokrycia wielowarstwowego. Widmo produktu sorpcji jest identyczne z widmem ksantogenianu ołowiu. We wszystkich widmach obserwowano produkty utlenienia ołowiu, produktu te zidentyfikowano jako mieszaninę węglanu i tlenku ołowiu (II), przy czym im wyższy potencjał polaryzacji próbki w roztworze ksantogenianu tym mniej produktów utlenienia obserwowano na powierzchni. Produkty te powstawały w wyniku utlenienia ołowiu w trakcie kontaktu próbki z powietrzem atmosferycznym podczas przenoszenia próbki z roztworu do spektrometru, co świadczy o tym, że powstająca warstwa produktu sorpcji ksantogenianu nie zabezpiecza powierzchni ołowiu przed utlenianiem. W wyniku naświetlania powierzchni promieniowaniem rentgenowskim w trakcie pomiaru, powstały na powierzchni ołowiu ksantogenian ołowiu rozkłada się do produktu, którego widmo jest identyczne z widmem siarczku ołowiu. Można temu zapobiec przeprowadzając pomiar w temperaturze ciekłego azotu.

5

Nadmiar powierzchniowy antymonu i siarki w stopach Cu-Sb oraz Cu-S

Siwiec G., Botor J.

Rudy i Metale Nieżelazne

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2005

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R. 50, nr 4

162-164

PL

Opierając się na wynikach przeprowadzonych metodą kropli leżącej pomiarów napięcia powierzchniowego ciekłej miedzi oraz ciekłych stopów Cu-Sb i Cu-S opracowano zależności opisujące zmiany tego parametru w funkcji aktywności, odpowiednio antymonu i siarki. Na ich podstawie określono nadmiar powierzchniowy Sb i S w ciekłej miedzi. Stwierdzono, że zdecydowanie większą adsorpcję powierzchniową od antymonu wykazuje siarka.

EN

Based on the measurements of surface tension of a liquid copper and liquid Cu-Sb and Cu-S alloys, performed by the sessile drop method, the dependencies describing variability of this parameter as a function of activity of antimony and sulphur, respectively, have been derived. These were used to determine surface excess of Sb and S in liquid copper. It was found that sulphur exhibits much higher surface adsorption than antimony.

6

Kinetics of marine surfactant adsorption at an air water interface. Baltic Sea studies

Pogorzelski S.J., Kogut A. D.

Oceanologia

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2001

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No. 43 (4)

389-404

EN

The paper contains the results of studies of natural surface film adsorption kinetics carried out in inland waters and in shallow offshore regions of the Baltic Sea during 2000-01 under calm sea conditions. The novel approach presented here for the adsorption dynamics is based on the mixed kinetic-diffusion model and analyses of the surface pressure-time plots at short (t →0) and long( t →∞) adsorption time intervals. Values of the effective relative diffusion coefficient Deff / D (= 0.008-0.607) and energy barrier for adsorption Ea / RT (= 0.49-7.10) agree well with the data reported for model non-ionic surfactant solutions of pre-cmc concentrations. Wind speed is one of the factors affecting the adsorption barrier via the increased surface pressure of the natural film exposed to wind shear stress (~ U102), and enters the relation Ea / RT = 1.70 U101/3.