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1

The effect of oil-water interfacial tension on the stability of oil emulsions

Gurbanov Guseyn R., Gasimzade Aysel V.

Nafta-Gaz

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2024

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R. 80, nr 3

179--185

EN

The stability of crude oil emulsions sourced from wells in two distinct fields distinguished by varying physicalchemical properties was analysed. The oil taken from the wells of Muradkhanli and Balakhani fields of State Oil Company of the Azerbaijan Republic (SOCAR) has been used as the research object. Demulsification of both oils, whose composition differs in the amount of high molecular compounds, has been investigated through the static settling method for 2, 4, 6, 8, 10 and 12 hours, and the amount of residual water in the oil has been recorded. In the same time interval, the oils have been tested by adding n-hexane and phenol to them, respectively. During the experiments, it was discovered that after the addition of n-hexane, which is a saturated hydrocarbon, the surface tension force increased in both oil samples and caused the formation of water in the form of a dispersed phase in the oil, which resulted in an increase in stability. In particular, as the concentration of n-hexane in oil increased, oil emulsions became aggregative and kinetically stable. The experiments conducted involving the addition of phenol to oils revealed that an increase in the volume of phenol in the oil led to a decrease in the surface tension force at the oil-water boundary, thereby accelerating the demulsification process. Subsequently, the research extended to investigating the emulsion stability of the oil samples by adding phenol and n-hexane in varying proportions. It was observed that an increase in the phenol ratio expedited the demulsification process, whereas a higher hexane ratio weakened it. Throughout the experimental tests, fluctuations in demulsification rates were noted upon the addition of organic substances to the oil samples. Furthermore, an increase in the concentration of high molecular compounds in the oil composition resulted in elevated surface tension, posing challenges in separating the water phase from the oil. The demulsification ability of organic substances added to crude oil samples, compositions A, B and C (25% n-hexane and 75% phenol (conditional name A), 50% n-hexane and 50% phenol (conditional name B), 75% n-hexane and 25% phenol (conditional name C)) prepared on the basis of these organic substances was examined depending on the surface tension.

PL

Przeanalizowano stabilność emulsji ropy naftowej pobranej z odwiertów w dwóch odrębnych złożach, charakteryzujących się zróżnicowanymi właściwościami fizykochemicznymi. Ropa pobrana z odwiertów na złożach Muradkhanli i Balakhani należących do Państwowej Kompanii Naftowej Republiki Azerbejdżanu (SOCAR) została wykorzystana jako obiekt badawczy. Deemulgacja obu rodzajów ropy, których skład różni się ilością związków o dużej masie cząsteczkowej, została zbadana za pomocą metody statycznej sedymentacji przez 2, 4, 6, 8, 10 i 12 godzin, po czym zarejestrowano ilość wody pozostałej w próbce. W tych samych przedziałach czasowych przetestowano analizowane próbki ropy poprzez dodanie do nich odpowiednio n-heksanu i fenolu. Podczas eksperymentów odkryto, że po dodaniu n-heksanu, który jest węglowodorem nasyconym, siła napięcia powierzchniowego wzrosła w obu próbkach ropy, co spowodowało powstanie wody w postaci fazy rozproszonej w ropie, co zaowocowało zwiększeniem stabilności. W szczególności, w miarę wzrostu stężenia n-heksanu w ropie, emulsje ropne stały się agregacyjne i kinetycznie stabilne. Przeprowadzone eksperymenty dotyczące dodania fenolu do ropy wykazały, że wzrost objętości fenolu w ropie spowodował zmniejszenie siły napięcia powierzchniowego na granicy ropa-woda, przyspieszając tym samym proces deemulgacji. Następnie badania zostały rozszerzone na badanie stabilności emulsji próbek ropy poprzez dodanie fenolu i n-heksanu w zróżnicowanych proporcjach. Zaobserwowano, że wzrost stosunku fenolu przyspieszył proces demulsyfikacji, podczas gdy wyższy stosunek heksanu osłabił go. W trakcie testów eksperymentalnych odnotowano wahania w tempie deemulgacji po dodaniu substancji organicznych do próbek ropy. Ponadto wzrost stężenia związków o dużej masie cząsteczkowej w składzie ropy spowodował wzrost napięcia powierzchniowego, co utrudniło oddzielanie fazy wodnej od ropy. Zbadano zdolność deemulgacyjną substancji organicznych dodanych do próbek ropy naftowej, kompozycji A, B i C (25% n-heksanu i 75% fenolu (nazwa warunkowa A), 50% n-heksanu i 50% fenolu (nazwa warunkowa B), 75% n-heksanu i 25% fenolu (nazwa warunkowa C)), przygotowanych na podstawie tych substancji organicznych, w zależności od napięcia powierzchniowego.

2

Synergistic mechanism of dodecylamine/octanol mixtures enhancing lepidolite flotation from the self-aggregation behaviors at the air/liquid interface

Bai Yang, Xu Mengxu, Wen Weixiang, Zhu Shifei, Mo Weichen, Yan Pingke

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 6

art. no. 176510

EN

Surface tension measurements and molecular dynamics (MD) simulations were used to explore the flotation foam properties and self-aggregation behaviors of dodecylamine (DDA)/octanol (OCT) mixtures formed with different mole ratios at the air/liquid interface. Based on the surface and thermodynamic parameters, the DDA/OCT mixtures exhibited greater interfacial activities and adsorption capacities than their individual components. The MD simulations showed that DDA and OCT were aggregated through hydrogen bonding, coulombic forces and hydrophobic association. OCT was inserted into the DDA adsorption layer, causing the alkyl chains of both DDA and OCT to extend from water to air at varying heights and angles. The addition of OCT improved the hydration of the amino groups and reduced the overall number of hydrogen bonds. The stability of the flotation foam decreased, and the high viscosity and difficult defoaming of the DDA flotation foam were significantly improved. When the DDA/OCT mole ratio was 2:1, the included angle formed between the alkyl chains and the interface was maximized, leading to enhanced compatibility among the alkyl chains, and the hydrogen bond energy was relatively large, which showed a strong synergistic effect. The MD simulation findings were consistent with the results obtained from the lepidolite flotation and surface tension experiments conducted in this study; our results could provide a theoretical foundation for the selection of superior mixed collectors and frothers.

3

Flotation of copper-bearing shale at different pH values of solutions and sodium chloride concentrations

Sajewicz Jakub, Ratajczak Tomasz

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 6

art. no. 176242

EN

Flotation of copper-bearing shale in aqueous solutions of NaCl at their different pH values was investigated. The tests were carried out in a laboratory flotation machine. The pH range was between 5 and 10 while NaCl concentrations were 0.5M, 1.0M and 2.0M. It was observed that the flotation recovery of the copper shale was increasing with the increase of pH and concentration of the salt solution. On the basis of thermodynamic and hydrodynamic considerations it was postulated that the increasing surface tension was responsible for better shale flotation observed with increasing salt concentration. The observed improved shale flotation caused by increasing pH is most likely due to changes in the properties of the thin film between particle and bubble including mosaic structure of water on the surface of shale. It was shown that the zeta potential of shale particles, zeta potential of air bubbles, solution surface tension, and shale hydrophobicity were not responsible for the increasing with pH recoveries.

4

Control of capillary instability under hydrodynamic impact on the reservoir

Panahov Geylani M., Abbasov Eldar M., Sultanov Babek N.

Nafta-Gaz

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2023

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R. 79, nr 2

71--83

EN

The paper presents the results of studies on optimisation of water impact on a reservoir by means of sequential periodic increase in hydrodynamic pressure in order to extract capillary trapped oil. The method provides a coordinated account of both displacement conditions and capacitive-filtration characteristics of fluid-saturated reservoirs. The results of experimental, theoretical and field studies of mass transfer processes in the presence of hydrodynamic nonequilibrium in heterogeneous porous media are presented. This paper considers a case where capillary forces are the determining factor for the displacement of immiscible liquids. Laboratory test results have shown that the formation of CO2 in the reaction of an alkaline solution with naphthenic components can make an additional contribution to the control of surface tension in porous media. A series of experimental studies were carried out on a core sample model to simulate the oil displacement by in-situ generated CO2 gas-liquid system. The article offers an analytical and technological solution to the problem of ensuring the value of “capillary number” and capillary penetration corresponding to the most complete extraction of trapped oil by regulating the “rate” of filtration (hydrodynamic injection pressure). The paper presents the field cases of implementing the new reservoir stimulation techniques to increase sweep efficiency. For effective residual oil recovery in fluid flow direction, conditions of stepwise (staged) maintenance of specified hydrodynamic water pressure at the boundary of injection contour are considered. Estimated calculations allow to determine time duration and stage-by-stage control of injection pressure as a requirement for reaching the expected increase in oil recovery.

PL

W artykule przedstawiono wyniki badań nad optymalizacją oddziaływania wody na złoże poprzez sekwencyjne, okresowe zwiększanie ciśnienia hydrodynamicznego w celu wydobycia kapilarnie zatrzymanej ropy. Metoda ta pozwala w sposób skoordynowany uwzględnić zarówno warunki wyporu, jak i charakterystykę kapilarno-filtracyjną złóż nasyconych cieczą. Przedstawiono wyniki badań doświadczalnych, teoretycznych i praktycznych procesów przenoszenia masy w obecności braku równowagi hydrodynamicznej w heterogenicznych ośrodkach porowatych. W artykule rozpatrywany jest przypadek, w którym siły kapilarne są czynnikiem decydującym o wypieraniu niemieszalnych cieczy. Wyniki badań laboratoryjnych wykazały, że powstawanie CO2 w reakcji roztworu zasadowego ze składnikami naftenowymi może mieć dodatkowy udział w kontroli napięcia powierzchniowego w ośrodkach porowatych. Przeprowadzono serię badań eksperymentalnych na modelu próbki rdzeniowej w celu symulacji wypierania ropy przez generowany in-situ układ gazowo-cieczowy CO2. W artykule zaproponowano analityczne i technologiczne rozwiązanie problemu zapewnienia wartości „liczby kapilarnej” i przenikania kapilarnego odpowiadających najbardziej pełnemu wydobyciu zatrzymanej ropy, poprzez regulację „szybkości” filtracji (ciśnienia zatłaczania hydrodynamicznego). W artykule przedstawiono przykłady praktycznego zastosowania nowych technik stymulacji złoża w celu zwiększenia efektywności wydobycia. W celu osiągnięcia efektywnego wydobycia ropy resztkowej w kierunku przepływu cieczy rozważono warunki stopniowego (podzielonego na etapy) utrzymywania określonego ciśnienia hydrodynamicznego wody na granicy konturu zatłaczania. Przeprowadzone obliczenia szacunkowe pozwalają na określenie czasu trwania i etapowego kontrolowania ciśnienia zatłaczania jako warunku osiągnięcia oczekiwanego wzrostu odzysku ropy.

5

Badania wpływu środków pieniących na skuteczność wynoszenia wody złożowej z odwiertu

Kluk Dorota, Steliga Teresa, Bęben Dariusz

Nafta-Gaz

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2023

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R. 79, nr 6

420--427

PL

W artykule zaprezentowano badania spienialności wód złożowych za pomocą środków powierzchniowo czynnych (SPCz) o handlowych nazwach BioLight 30/380, BioAcid 30/380 oraz BioCond Plus 30/380. Stosowane SPCz występowały w postaci świec pieniących. Wody poddawane testom pienienia charakteryzowały się różnorodnymi parametrami fizycznymi i chemicznymi, szczególnie pod kątem mineralizacji (260–311 664 mg/dm3 ) i zawartości substancji organicznych (0–102 mg/dm3 ). Testy wpływu środków pieniących na skuteczność spieniania i wynoszenia wód złożowych z odwiertu prowadzono na stanowisku laboratoryjnym symulującym kolumnę wydobywczą gazu ziemnego. Podczas testów pienienia wód złożowych, prowadzonych kolejno z dawkami środków powierzchniowo czynnych: 1,5 g/m3 , 3,0 g/m3 oraz 5,0 g/m3 , wykonywano pomiary: napięcia powierzchniowego wody, objętości wytworzonej piany w funkcji czasu oraz wypienionej wody złożowej. Kryterium wyboru efektywności działania środka powierzchniowo czynnego dla badanej wody było jej skuteczne wynoszenie w strukturze piany z instalacji symulującej zawodniony odwiert gazowy oraz minimalizacja dawki wprowadzanego do wody środka pianotwórczego. Wyniki przeprowadzonych badań laboratoryjnych uzyskane w ramach realizowanej pracy umożliwiły zaproponowanie efektywnie działających środków powierzchniowo czynnych w kontekście spieniania i wynoszenia wód złożowych z odwiertu. W praktyce powiązanie wyników badań laboratoryjnych z rodzajem i dawkowaniem środków pieniących, z właściwościami wody złożowej i parametrami eksploatacji złoża gazu pozwoli na wskazanie, jakie środki i w jakich ilościach mogą w efektywny sposób usprawnić eksploatację danego rodzaju złoża gazu ziemnego. Wyniki prac przyczynią się do zwiększania stopnia sczerpania zasobów geologicznych złóż węglowodorów.

EN

The article presents studies of formation water foamability using surfactants with the trade names BioLight 30/380, BioAcid 30/380 and BioCond Plus 30/380. Foaming candles were used as the surfactants. The waters subjected to foaming tests were characterized by various physical and chemical parameters, especially in terms of mineralization (260–311,664 mg/dm3 ) and the content of organic substances (0–102 mg/dm3 ). Tests of the effect of foaming agents on the effectiveness of foaming and raising formation water from the borehole were carried out on a laboratory stand simulating a natural gas well. During the tests of formation water foaming, carried out successively with surfactants doses of 1.5, 3.0 and 5.0 g/m3 , the following measurements were made: surface tension of water, volume of generated foam as a function of time and foamed formation water. The criterion for choosing the effectiveness of the surfactant for the tested water was: effective removal of water in the form of foam from the installation simulating a flooded gas well and the minimization of the dose of the foaming agent introduced into the water. In practice, linking the results of laboratory tests with the type and dosage of foaming agents, formation water properties and exploitation parameters of gas reservoir will make it possible to indicate which agents and in what quantities can effectively improve the exploitation of a given type of natural gas deposit. The results of the works will contribute to increasing the degree of depletion of geological resources of hydrocarbon deposits.

6

Microalloying of Continuous Cast Aluminum Strip and Structural Modification Using Plastic Treatment to a 9 μm Foil (Patent no. 39762, P-377/76)

Purenović M. M., Purenović Jelena M., Baralić J. Č.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

345--357

EN

Innovative procedure of microalloying continuous cast aluminum strip, thickness 10 mm, by Be, Zr and Mn using 3C Pechiney technology (no. 39762, P-377/76), and modifying the existing parameters for strip casting and crystallization was implemented under industrial conditions with two randomly selected batches 2×8 tones, without previous selection of standardized quality of aluminum, purity Al 99.5%, obtained by electrolysis. The application of microalloying and overall structural modification of the technology resulted in obtaining nanoscale, ultra-thin, compact oxide high-gloss film with uniform surface of continuous cast strip, instead of the usual thick and porous oxide film. The outcome of microalloying the obtained equiaxed fine-grained nano/micro structure was avoiding anisotropic and dendritic microstructure of the strip, and improving deformation and plastic properties of modified continuous cast strip subjected to the technology of plastic treatment by rolling until the desired foil thickness of 9 μm was obtained. The invention of microalloying and structural modification, including multiplying effect of several components, directly or indirectly, changed numerous structurally-sensitive properties. The obtained nano/micro structure of crystal grains with equiaxed structure resulted in the synergy of undesirable <111> and inevitable <100> and <110> textures. Numerous properties were significantly enhanced: elastic modulus was improved, and intensive presence of cracks in warm forming condition was prevented due to rapid increase of the number of grains to 10000 grains/cm2 in as-cast state.

7

The effect of adjuvant concentration on changes of spray characteristics and spraying parameters for selected types of nozzles

Milanowski Marek, Subr Alaa, Parafiniuk Stanisław, Różańska-Boczula Monika

Agricultural Engineering

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2022

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Vol. 26, No. 1

119--132

EN

The paper presents the results of the research on the influence of the adjuvant concentration on the size of the drops produced by the spray nozzles of agricultural sprayers. For the tests, adjuvant Normaton with the composition of total nitrogen, amide nitrogen (N-NH2) and phosphorus pentoxide (P2O5) was used. The adjuvant was added to the water taken from the municipal water supply system of the city of Lublin. The tests were carried out for three concentrations, i.e. 75%, 100%, and 125% of the adjuvant concentration recommended by the manufacturer, and water without the adjuvant. The surface tension of water with adjuvant was examined for each nozzle. Then, the size of the obtained droplets was measured for each adjuvant concentration. Two types of nozzles were used for spraying, standard nozzle AP 120-03 and 6MSC injector nozzle, both with the same nozzle flow rate, but with a different design. The size of the droplets produced was measured on a HELOSVARIO laser diffractometer by Sympatec. The droplet measurement was performed at a pressure of 3 bar. The nozzle was placed 50 cm above the diffractometer laser light line. The droplet size was measured in three places of the sprayed liquid, i.e. in the position of the nozzle axis, 30 and 60 cm from the nozzle axis. It was shown that the addition of the adjuvant influenced the number of droplets produced in the indicated droplet size classes.

PL

W pracy przedstawiono wyniki badań nad wpływem stężenia adiuwanta na wielkość kropel wytwarzanych przez rozpylacze rolnicze. Do badań użyto adiuwantu Normaton o składzie: azot całkowity, azot amidowy (N-NH2) i pięciotlenek fosforu (P2O5). Adiuwant dodawano do wody pobieranej z miejskiej sieci wodociągowej z Lublina. Badania przeprowadzono dla trzech stężeń, tj. 75%, 100% i 125% stężenia adiuwanta zalecanego przez producenta, oraz dla wody bez dodatku adiuwanta. Dla każdego stężenia adiuwanta badano napięcie powierzchniowe, a następnie mierzono wielkość uzyskanych kropel adiuwanta. Do opryskiwania użyto dwóch typów rozpylaczy: rozpylacza standardowego AP 120-03 i rozpylacza eżektorowego 6MSC - oba o takim samym natężeniu przepływu, ale o innej konstrukcji. Wielkość wytwarzanych kropel mierzono za pomocą dyfraktometru laserowego HELOS-VARIO firmy Sympatec. Pomiar kropel przeprowadzono pod ciśnieniem 3 barów. Rozpylacz umieszczano 50 cm nad linią światła lasera dyfraktometru. Wielkość kropel mierzono w trzech miejscach rozpylanej cieczy, tj. w na osi rozpylacza oraz w odległości 30 i 60 cm od osi rozpylacza. Wykazano, że dodatek adiuwanta wpływa na liczbę wytwarzanych kropel we wskazanych klasach wielkości kropel.

8

Adsorpcja dwufunkcyjnych labilnych surfaktantów kationowych na granicy faz ciecz/gaz : opis za pomocą modelu kwazi-dwuwymiarowego elektrolitu

Frąckowiak Renata, Para Grażyna, Lamch Łukasz, Szyk-Warszyńska Lilianna, Wilk Kazimiera A., Warszyński Piotr

Wiadomości Chemiczne

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2021

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[Z] 75, 9-10

1119--1155

EN

There is an increasing interest in surfactants that comprise a linkage that breaks down in a controlled way. The most known examples of the cleavage mechanism include acid or alkaline hydrolysis, UV irradiation, enzymatic or heat decomposition. For practical reasons, the labile grouping can be inserted between the hydrophobic tail of the surfactant and the polar head group. Chemically and/or enzymatically induced cleavage of this labile bond would cause the separation of the polar part and the hydrophobic tail and, consequently, change of surface activity, an event usually referred to as the primary degradation of the surfactant. Dicephalic labile cationic surfactants belong to the class of surface active compounds with many potential applications often associated with their biological activity for a wide range of bacteria, viruses, fungi, or algae. Thus, they can be used in disinfecting agents or for protecting against the occurrence of these microorganisms. They adsorb well on negatively charged surfaces, which can be used in the treatment of fabrics. Due to excellent antistatic properties, they can be used for the final rinsing of fabrics, especially synthetic ones. In flotation processes, they can act as collectors, and in catalysis, they can be used as phase transfer catalysts or templates for zeolite synthesis. We present the surface quasi-two-dimensional electrolyte (STDE) model as a universal model for the description of ionic surfactants’ adsorption at fluid interfaces that explicitly considers the electric double formation upon surfactant adsorption. The model was adapted to describe phenomena occurring for adsorption of dicephalic surfactants as counterion specificity or formation of surfactant ioncounterion associates. As an example, we applied the model to explain the mechanism of adsorption at water/air interface of novel dicephalic cationic surfactants, N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dimethylsulfates, both belonging to the class of chemodegradable surfactants having amide bond between two quaternary amine cationic groups and a single hydrophobic tail. Additionally, we used the same model to describe adsorption isotherms of N,N-bis[3,3- (dimethylamine)propyl]alkylamide dichlorides, having as two hydrophilic groups tertiary amines, which charge is pH-dependent. Application of the STDE model allowed an excellent description of experimental adsorption isotherm of dicephalic cationic surfactants and explained the specific features connected with the presence of multicharged headgroup.

9

Investigation of the frother effect in two and three phases systems on bubble size, surface tension, recovery and grade in chalcopyrite flotation

Ceylan Adnan, Bulut Gülay

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 6

23--35

EN

In this study, the effect of frother was investigated in two and three phases in the systems of the flotation. While the two-phase system consisted of liquid and gas, the three-phase systems contained a chalcopyrite ore. The study of three-phase systems was performed with the ore on a laboratory and plant scale. Effect of the amount and type of the frothers, their mixtures, and pH were examined depending on the bubble size, grade of the concentrate, and the recovery of chalcopyrite flotation. The results showed that as the amount of frothers increased, there was a reduction in the bubble size in all experiments. Additionally, the frother mixtures gave a positive effect on the chalcopyrite flotation. One of the most important purposes of flotation frothers shrinks the air bubble. As can be understood from the tests this time reduction of the frothers bubble size has a positive effect on the flotation. Likewise, it increases the foam stable value. It is observed from this study that increasing the amount of frothers decreases the surface tension and bubble size at different pH.

10

Method of Determining the Surface Tension and Surface Energy of Tribological Wear Particles

Sadowski Jan

Tribologia

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2020

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nr 5

61--71

EN

Surface tension of friction wear product material is linked with unit mechanical work of newly-formed surfaces of solids. A definition of surface energy also addresses the thermal effect, which is indirectly connected with wear. Physical differences between the development of liquids and solids surfaces are discussed. Both of the quantities defined are described in analytical terms and their value is determined for a selected example of experimental testing. The discussion is based on the first law of thermodynamics using the concept of specific enthalpy of wear products. Boundaries of an area in space where mechanical energy is dissipated and dimensions of a wear particle being formed are taken into account. Mechanical and thermal parts of the energy balance are differentiated.

PL

Napięcie powierzchniowe materiału produktów zużycia tarciowego zostało powiązane z jednostkową pracą mechaniczną nowo utworzonej powierzchni ciał stałych. W definicji energii powierzchniowej uwzględniono również efekt cieplny, który jest pośrednio związany ze zużyciem. Podkreślono różnice o charakterze fizycznym między rozwojem powierzchni cieczy i ciał stałych. Obie zdefiniowane wielkości zostały opisane analitycznie, a ich wartości określono dla wybranego przykładu badań eksperymentalnych. Rozważania oparto na pierwszej zasadzie termodynamiki, w której wykorzystano koncepcję entalpii właściwej produktów zużycia. Uwzględniono granice obszaru przestrzennego, w którym energia mechaniczna jest rozpraszana, oraz wymiary powstałej cząstki zużycia. W bilansie energetycznym rozdzielono część mechaniczną i termiczną.

11

Comparison of components and parameters of some sulfide minerals surface tension with regards to stability of mineral-air bubble system

Jańczuk Bronisław, Zdziennicka Anna

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

22--31

EN

The measurements of the advancing contact angle of water, glycerol, formamide, ethylene glycol, diiodomethane, α-bromonaphthalene, 1,2,3-tribromopropane on unoxidized and oxidized galena, pyrite, chalcopyrite, djurleite, bornite and covellite at the temperature equal 293 K were made. Additionally, the measurements of the force air bubble detachment from these sulfide minerals including also chalcocite in water were performed. Using the values of the obtained contact angle of water, glycerol, formamide, ethylene glycol, diiodomethane, α-bromonaphthalene, 1,2,3-tribromopropane the components and parameters of the unoxidized and oxidized sulfide minerals surface tension were calculated. For this calculation the van Oss et al. method was applied after analysis of the components and parameters of the surface tension of liquids used for contact angle measurements. Taking into account the contact angle of water on the sulfide minerals, the detachment force of air bubble from these minerals in water was determined using our equation and comparing to that of measured one. As follows from the measurements and calculations the wetting properties of sulfide minerals and the stability of mineral-air bubble depends to a larger extent on the degree of sulfide minerals oxidation than on the type of mineral.

12

Numerical and analytical calculations of the free surface flow between two semi-infinite straights

Chedala Fatma Zohra, Amara Abdelkader, Meflah Mabrouk

Journal of Applied Mathematics and Computational Mechanics

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2020

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Vol. 19, nr 4

21--32

EN

The problem of two-dimensional flow with the free surface of the jet in a region between two semi-infinite straights intersections at point O is calculated analytically for each angle Beta and numerically for each of the various values of the Weber number and angle Beta. By assuming that the flow is potential, irrotational and that the fluid is incompressible and inviscid, and by taking account only the surface tension for a numerical method using the series truncation, and without the effect of gravity and surface tension for the analytic method utilize the hodograph transformation. The obtained results confirmed a good agreement between them when the Weber number tends to infinity, and the comparison of these surface shapes is illustrated.

13

Calculation of Surface Tension of Multicomponent Silicate Solutions

Kalisz D.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 4

29--35

EN

Surface phenomena play a major role in metallurgical processes; their operation results, among others, from the surface tension of liquid oxidic systems. One of the methods of determining surface tension of oxidic systems is performing calculations with Butler’s method. Surface tension was calculated for two- and three-component liquid oxidic systems typical of metallurgical processes. The determined dependence of surface tension in FeO-SiO2 at temp. 1773 K and CaO-SiO2 at temp.1873 K showed that with the growing participation of SiO2 surface tension decreased. Analogous calculations were performed for three-component systems: CaO-Al2O3-SiO2 and MnO-Al2O3- SiO2. The results of calculations of surface tension were determined for temp. 1873 K and compared with the results obtained by T. Tanaka et al. [19]. In both cases the increase of Al2O3 content resulted in a growth of surface tension. The simulation results were higher than experimental result, as compared to the literature data.

14

An investigation of air/water interface in mixed aqueous solutions of KCl, NaCl, and DAH

Gungoren Can

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 5

1259--1270

EN

Flotation of soluble salts such as borax, potash, and trona is carried out in their saturated solutions. The high ion concentration of the flotation suspension can affect the floatability of the minerals as well as the coalescence behaviors of the bubbles. The bubble coalescence can be inhibited in the presence of dissolved ions at high ion concentrations as well as with the use of surfactants. In this study, the effect of the mixtures of KCl, NaCl, and dodecyl amine hydrochloride (DAH) on air/water interface was investigated with surface tension and bubble coalescence time measurements for potash flotation. The surface tension measurements indicated that lower surface tension values obtained with mixed KCl and NaCl solutions than their single solutions. In addition, the surface tension of the mixed KCl and NaCl solutions increased with the NaCl and the ionic strength of the solution. The dynamic surface tension measurements indicated that while ion adsorption on air/water interface was so fast, DAH molecules required more time for adsorption probably related to the viscosity of the solution. In addition, the bubble coalescence time measurements showed that the bubble coalescence could be inhibited with the use of DAH in the absence and presence of KCl and NaCl. In the absence of DAH, the bubble coalescence time was determined as 100 ms, 270 ms, and 650 ms, respectively for 100% KCl, 100% NaCl, and 50%KCl+50% NaCl salt solutions. Therefore, the trend in the success of the salt solutions for the inhibition of bubble coalescence can be written as 100%KCl<50%KCl+50%NaCl<100% NaCl according to the bubble coalescence time. The results of this study indicated that there was no clear relationship between the surface tension and the inhibition of the bubble coalescence. However, the bubble coalescence time measurements showed that while the bubble coalescence time was 650 ms in the presence of Na+ ions, it was 100 ms in the presence of K+ ions 100 ms. It can be concluded from the results obtained from this study that the bubble coalescence phenomena may be managed by the specific ion pairing types in solutions which significantly affect the flotation recovery of minerals.

15

A fundamental study of monovalent and divalent ions on froth properties in the presence of terpenic oil

Li Yubiao, Wang Hongduo, Li Wanqing, Song Shaoxian

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 3

643--654

EN

In order to minimize fresh water usage, much attention has been paid to the flotation using saline or sea water. However, the effects of various ions in these waters on froth properties in flotation are not fully understood. In this study, the effects of electrolyte solutions containing NaCl, KCl, CaCl2, and MgCl2 at different concentrations in the presence of terpenic oil as a frother were investigated on froth performance, dynamic froth stability (DFS). It was found that KCl had the best synergistic effects with terpenic oil in reducing the solution surface tension. In the presence of terpenic oil, the DFS and half-life time were reduced with the increased ion concentration. Dynamics foamability index measurements (DFI) confirmed that the increased ion concentration increased the foamability, as frother did. In addition, Gibbs adsorption isotherm suggested that the amount of terpenic oil adsorbed at the gas-liquid interface was increased with the increased ion concentration. This study therefore indicated that the presence of ions can reduce the froth stability but not decline foamability due to terpenic oil, enlighting the application of saline or sea water in defoaming process in flotation.

16

Application of Ultrasonic Methods for Evaluation of High-Pressure Physicochemical Parameters of Liquids

Kiełczyński Piotr, Ptasznik Stanisław, Szalewski Marek, Balcerzak Andrzej, Wieja Krzysztof, Rostocki Aleksander J.

Archives of Acoustics

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2019

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Vol. 44, No. 2

329--337

EN

An emerging ultrasonic technology aims to control high-pressure industrial processes that use liquids at pressures up to 800 MPa. To control these processes it is necessary to know precisely physicochemical properties of the processed liquid (e.g., Camelina sativa oil) in the high-pressure range. In recent years, Camelina sativa oil gained a significant interest in food and biofuel industries. Unfortunately, only a very few data characterizing the high-pressure behavior of Camelina sativa oil is available. The aim of this paper is to investigate high pressure physicochemical properties of liquids on the example of Camelina sativa oil, using efficient ultrasonic techniques, i.e., speed of sound measurements supported by paralel measurements of density. It is worth noting that conventional low-pressure methods of measuring physicochemical properties of liquids fail at high pressures. The time of flight (TOF) between the two selected ultrasonic impulses was evaluated with a cross-correlation method. TOF measurements enabled for determination of the speed of sound with very high precision (of the order of picoseconds). Ultrasonic velocity and density measurements were performed for pressures 0.1-660 MPa, and temperatures 3-30°C. Isotherms of acoustic impedance Za, surface tension σ and thermal conductivity k were subsequently evaluated. These physicochemical parameters of Camelina sativa oil are mainly influenced by changes in the pressure p, i.e., they increase about two times when the pressure increases from atmospheric pressure (0.1 MPa) to 660 MPa at 30°C. The results obtained in this study are novel and can be applied in food, and chemical industries.

17

The measurement technique of surface tension using inductance values

Dujpen T., Sa-ngiamvibool W.

Przegląd Elektrotechniczny

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2018

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R. 94, nr 4

118--121

EN

The objectives of this study were to examine correlations of inductance values on surface tension of water and to develop other techniques for measuring the surface tension of water using inductance values. The design was based on the variation of inductance values by moving the Ferrite cores that was connected with a conductor plate on water surface when conducting weight counterbalance. The results found that at the surface tension of 66.24 mN/m –71.20mN/m with the inductance values of 0.5mH, 1.0mH and 1.5mH coils.

PL

Celem pracy było zbadanie korelacji wartości indukcyjności naprężeń powierzchniowych wody oraz opracowanie nowych metod pomiaru naporu powierzchniowego wody przy użyciu wartości indukcyjności. Projekt został oparty na zmianie wartości indukcyjności rdzenia ferrytowego, który połączono z płytą przewodową na powierzchni wody przy równoważeniu wagi. Wyniki wykazały, że przy napięciu powierzchniowym 66,24 mN/m -71,20 mN/m indukcyjnoś cewek 0,5 wynosiła0.5 mH, 1.0 mH i 1.5 mH.

18

Stability of air nucleus in liquid water and cavitation inception on marine engineering

Fu Q., Chen M., Wang X., Zhu R., Zhang G.

Polish Maritime Research

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2018

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S 3

111--119

EN

The micro air nucleus widely distributed in the ocean is a necessary condition for the cavitation of hydraulic machinery in seawater. In order to study the stability of air nucleus in seawater and cavitation inception, the computational domain of water molecules with air nucleus was studied using the method of molecular dynamics simulation, and the transient characteristics of air nucleus in liquid water were obtained. The key factors influencing nuclei stability were analyzed. The results showed that air nucleus with a certain mass could maintain the dynamic equilibrium in liquid water. The internal density of air nuclei had a critical value that allowed the nuclei to stably exist in water. The air nuclei mass was the decisive factor in its equilibrium volume in water, and the two were positively correlated. The internal density of air nuclei was negatively correlated with the nuclei radius when the nuclei was stable in water. Liquid surface tension was an important factor affecting the stability of the air nuclei. The larger the initial radius of nuclei, the smaller the water pressure, and the more likely the cavitation occurs.

19

Components and parameters of synthetic chalcocite surface tension and its wettability by aqueous solution of n-octyl-β-D-glucopyranoside

Jańczuk B., Zdziennicka A.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 1

19--30

EN

The measurements of advancing contact angle of water, glycerol, formamide, ethylene glycol, diiodomethane, α-bromonaphthalene, 1,2,3-tribromopropane and aqueous solution of n-octyl-β-D-glucopyranoside (OGP) on unoxidized and oxidized synthetic chalcocite at the temperatures equal to 293, 303 and 313 K were made. Using the obtained contact angle values of the pure liquids the components and parameters of the unoxidized and oxidized synthetic chalcocite surface tension were calculated. For this calculation, different methods based on the Young equation were applied. It follows that the surface tension of both forms of chalcocite does not practically depend on the temperature in the range from 293 to 313 K. Taking into account the calculated values of components and parameters of unoxidized and oxidized chalcocite surface tension their wettability by the aqueous solution of n-octyl-β-D-glucopyranoside was considered. It appeared that wettability of the unoxidized chalcocite by aqueous solution of OGP can be predicted on the basis of the chalcocite surface tension components and parameters.

20

A novel technique to investigate the bubble coalescence in the presence of surfactant (MIBC) and electrolytes (NaCl and CaCl2)

Gungoren C., İslek E., Baktarhan Y., Kursun I., Ozdemir O.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 4

1215--1222

EN

An efficiency of flotation process is strongly dependent upon the collecting ability of air bubbles. On the other hand, the liquid film formed beetween two fully or partially mobile air/liquid interfaces being in contact has low stability, which leads to fast liquid drainage. Therefore, when they approach to each other, they tend to coalescence. Therefore, bubble coalescence is usually controlled with frothers in flotation process. Meanwhile, it is known that dissolved ions inhibit bubble coalescence. In this study, the bubble coalescence in the presence of MIBC was determined using a novel technique with a modified bubble-particle attachment timer. Additionally, the effect of NaCl and CaCl2 on bubble behavior was investigated along with surface tension and bubble coalescence time aspects. As a result of study, it is seen that the bubble coalescence time can be successfully determined with a bubble-bubble coalescence timer.