scholarly journals Zeta Potential of Pyrite Particles in Concentrated Solutions of Monovalent Seawater Electrolytes and Amyl Xanthate

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 584 ◽  
Author(s):  
Alvaro Paredes ◽  
Sergio M. Acuña ◽  
Leopoldo Gutiérrez ◽  
Pedro G. Toledo
Keyword(s):  
Zeta Potential ◽  
Streaming Potential ◽  
Monovalent Cations ◽  
Water Network ◽  
Anionic Sites ◽  
Concentrated Solutions ◽  
Salt Addition ◽  
Monovalent Ions ◽  
Low Salt ◽  
Copper Flotation

Charge screening and adsorption capacity of monovalent ions onto pyrite (Py) in aqueous suspensions and the effect of potassium amyl xanthate (PAX) has been studied by measuring the changes in zeta potential (zp) versus pH with streaming potential. PAX addition in the absence of salts leads to an increase in |zp| suggesting dissolution of the surface ferric hydroxides and recovery of bare Py, corroborating existing theories. In the presence of salt, addition of PAX at pH > 6, for which hydroxides interference in not expected, has little effect over the zp, except when Li is present. The water network around the polar head of PAX is expected to be similar to that of hydrated Li+ facilitating the linkage between them and, thus, the formation of Li-mediated Py–PAX bridges. We speculate that these bridges lead to a xanthate shield around anionic sites on Py, decreasing |zp|. An increased PAX dose amplifies the effect of Li as a Py activator but only at low salt. At high salt concentrations, >0.01 M, PAX molecules do not find room to percolate to the surface of Py. Results for monovalent cations should improve our understanding of copper flotation processes in the presence of Py in saltwater.

How to use alum with cationic dispersed rosin size

TAPPI Journal ◽  
2016 ◽  
Vol 15 (5) ◽  
pp. 331-335 ◽  
Author(s):  
LEBO XU ◽  
JEREMY MYERS ◽  
PETER HART
Keyword(s):  
Zeta Potential ◽  
Colloidal Particles ◽  
Streaming Potential ◽  
Excessive Amount ◽  
Paper Machine ◽  
Optimum Amount ◽  
Potential Measurement ◽  
Streaming Current ◽  
Wide Range ◽  
Laboratory Results

Retention of cationic dispersed rosin size was studied via turbidity measurements on stock filtrate with different alum and dispersed rosin size dosages. Stock charge characteristics were analyzed using both an analysis of charge demand determined via a streaming current detector and an evaluation of zeta potential of the fibers by streaming potential measurement. The results indicated that an optimum amount of alum existed such that good sizing retention was maintained throughout a wide range of dispersed rosin size dosages. However, when an excessive amount of alum was used and fines and colloidal particles were transitioned from anionic to cationic, the cationic size retention was reduced. Laboratory results were confirmed with a paper machine trial. All data suggested that a stock charge study was necessary to identify optimal alum dosage for a cationic dispersed rosin sizing program.

Effect of clay colloids on the zeta potential of Fe/Al oxide-coated quartz: a streaming potential study

2016 ◽  
Vol 16 (12) ◽  
pp. 2676-2686 ◽  
Author(s):  
Zhong-yi Li ◽  
Ren-kou Xu ◽  
Jiu-yu Li ◽  
Zhi-neng Hong
Keyword(s):  
Zeta Potential ◽  
Streaming Potential ◽  
Potential Study ◽  
Al Oxide

The Determination of Electrokinetic Coupling-Coefficient and Zeta Potential of Rock Samples by Electrokinetic Measurements

2012 ◽  
Vol 516-517 ◽  
pp. 1870-1873 ◽  
Author(s):  
Jun Wang ◽  
Heng Shan Hu
Keyword(s):  
Zeta Potential ◽  
Coupling Coefficient ◽  
Streaming Potential ◽  
Potential Method ◽  
Surface Conductivity ◽  
Reliable Estimate ◽  
Surface Conductance ◽  
Streaming Current ◽  
Low Concentrations

The electrokinetic effects are important in the understanding of electric properties in porous medium. In this study, the streaming potential and streaming current of saturated samples are measured at different concentrations, then three methods are applied to obtain the zeta-potential and electrokinetic coupling coefficient. The study shows that the results obtained from streaming potential and streaming current methods agree well with each other, but the results obtained from simplified streaming potential method become seriously inaccurate at low concentrations due to the influence of surface conductance. This experimental study also provides a reliable estimate of the surface conductivity and its contribution to zeta-potential at given concentrations.

Cation exchange in cell walls of gram-positive bacteria

1976 ◽  
Vol 22 (7) ◽  
pp. 975-982 ◽  
Author(s):  
Robert E. Marquis ◽  
Kathleen Mayzel ◽  
Edwin L. Carstensen
Keyword(s):  
Cation Exchange ◽  
Cell Walls ◽  
Divalent Cations ◽  
Teichoic Acid ◽  
Dry Weight ◽  
High Ionic Strength ◽  
Monovalent Cations ◽  
Anionic Sites ◽  
Gram Positive Bacteria ◽  
Anionic Groups

The relative affinities of various cations for anionic sites in isolated, bacterial cell walls were assessed by means of a technique involving displacement of one cation by another. The affinity series determined was [Formula: see text]. High affinity was correlated with low mobility of the bound ions in an electric field. The net cation-exchange capacities of walls isolated from a variety of bacteria were estimated by preparing the magnesium forms of the walls, washing them well with deionized water to remove supernumerary ions, and then completely displacing the magnesium with Na+ or H+. Total amounts of magnesium displaced varied from 73 μmol per gram dry weight, for walls of the teichoic acid-deficient 52A5 strain of Staphylococcus aureus to about 520 μmol per gram for Bacillus megaterium KM walls. The amount of displacable magnesium was inversely related to the physical compactness of the walls, except for walls of Streptococcus mutans GS-5. It was found that magnesium or calcium ions can each neutralize, or pair with, two anionic groups in walls suspended in ion-deficient media. Previous work had indicated that these ions may pair with only one anionic group at high ionic strength. Therefore, it appeared that there is a great deal of flexibility in the arrangement of charged groups in the wall. It was concluded also that for cells growing in commonly used laboratory media, which generally contain large excesses of monovalent versus divalent cations, there is a mix of small, cationic counterions in the wall and that monovalent cations may predominate even though the wall has higher affinity for divalent ions.

Zeta potential of particle bilayers on mica: A streaming potential study

2011 ◽  
Vol 360 (1) ◽  
pp. 195-203 ◽  
Author(s):  
Maria Zaucha ◽  
Zbigniew Adamczyk ◽  
Jakub Barbasz
Keyword(s):  
Zeta Potential ◽  
Streaming Potential ◽  
Potential Study

Apparatus for determination of zeta potentials from streaming potentials

1963 ◽  
Vol 18 (6) ◽  
pp. 1263-1264 ◽  
Author(s):  
R. E. Beck ◽  
V. Mirkovitch ◽  
P. G. Andrus ◽  
R. I. Leininger
Keyword(s):  
Zeta Potential ◽  
Streaming Potential ◽  
Salt Solutions ◽  
Streaming Potentials ◽  
Zeta Potentials ◽  
Quartz Capillary ◽  
Flow Through

A system was developed to measure the streaming potential generated between the ends of a capillary by the flow of a fluid through the capillary. Zeta potential can be calculated from the streaming potential. Adequate sensitivity and reproducibility were achieved by making special electrodes: silver wires plated in KCl solution and embedded in agar, careful electrical shielding, and provision for reversal of flow through the capillary to minimize electrode errors. The apparatus was developed to measure streaming potentials generated by either RingerS's solution or blood in contact with capillaries made of different materials such as quartz, polyethylene, etc. An example of a determination using a quartz capillary is presented. interfaces; blood; salt solutions; glass; quartz Submitted on February 25, 1963

A new streaming potential chamber for zeta potential measurements of particulates

2010 ◽  
Vol 81 (1) ◽  
pp. 015106 ◽  
Author(s):  
N. Guzelsu ◽  
C. Wienstien ◽  
S. P. Kotha
Keyword(s):  
Zeta Potential ◽  
Streaming Potential

Seismo-electric Conversion in Sandstones and Shales using 2 Different Experimental Approaches, Modelling and Theory

2020 ◽  
Author(s):  
Paul Glover ◽  
Rong Peng ◽  
Piroska Lorinczi ◽  
Bangrang Di
Keyword(s):  
Zeta Potential ◽  
Numerical Modelling ◽  
Clay Minerals ◽  
Shale Gas ◽  
Streaming Potential ◽  
Oil Reservoirs ◽  
Low Permeability ◽  
Experimental Measurements ◽  
Frequency Range ◽  
Potential Coefficient

<p>The development of seismo-electric (SE) exploration techniques relies significantly upon being able to understand and quantify the strength of frequency-dependent SE conversion. However, there have been very few SE measurements or modelling carried out. In this paper we present two experimental methods for making such measurements, and examine how the strength of SE conversion depends on frequency, porosity, permeability, and why it is unusual in shales. The first is based on an electromagnetic shaker and can be used in the 1 Hz to 2 kHz frequency range. The second is a piezo-electric water-bath apparatus which can be used in the 1kHz to 500 kHz frequency range.</p><p>The first apparatus has been tested on samples of Berea sandstone. Both the in-phase and in-quadrature components of the streaming potential coefficient have been measured with an uncertainty of better than ±4%. The experimental measurements show the critical frequency at which the quadrature component is maximal, and the frequency of this component is shown to agree very well with both permeability and grain size. The experimental measurements have been modelled using several different methods.</p><p>The second apparatus was used to measure SE coupling as a function of porosity and permeability, interpreting the results using a micro-capillary model and current theory. We found a general agreement between the theoretical curves and the test data, indicating that SE conversion is enhanced by increases in porosity over a range of different frequencies. However, SE conversion has a complex relationship with rock permeability, which changes with frequency, and which is more sensitive to changes in the petrophysical properties of low-permeability samples. This observation suggests that seismic conversion may have advantages in characterizing low permeability reservoirs such as tight gas and tight oil reservoirs as well as shale gas reservoirs.</p><p>We have also carried out SE measurements on Sichuan Basin shales (permeability 1.47 – 107 nD), together with some comparative measurements on sandstones (0.2 – 60 mD). Experimental results show that SE conversion in shales is comparable to that exhibited by sandstones, and is approximately independent of frequency in the seismic frequency range (<1 kHz). Anisotropy which arises from bedding in the shales results in anisotropy in the streaming potential coefficient. Numerical modelling has been used to examine the effects of varying zeta potential, porosity, tortuosity, dimensionless number and permeability. It was found that SE conversion is highly sensitive to changes in porosity, tortuosity and zeta potential in shales. Numerical modelling suggests that the cause of the SE conversion in shales is enhanced zeta potentials caused by clay minerals, which are highly frequency dependent. This is supported by a comparison of our experimental data with numerical modelling as a function of clay mineral composition from XRD measurements. Consequently, the sensitivity of SE coupling to the clay minerals suggests that SE exploration may have potential for the characterization of clay minerals in shale gas and shale oil reservoirs.</p>

EXCHANGE EQUILIBRIA FOR Al–BENTONITE AND MONOVALENT CATIONS

1965 ◽  
Vol 45 (2) ◽  
pp. 177-183 ◽  
Author(s):  
David Chen
Keyword(s):  
Equilibrium Distribution ◽  
Base Saturation ◽  
Monovalent Cations ◽  
Distribution Constant ◽  
Monovalent Ions ◽  
Wyoming Bentonite ◽  
Distribution Equation

Aluminum-saturated Wyoming bentonite, suspended in a solution of NH4Cl, KCl, or LiCl, was adjusted to a range of degrees of base saturation with the respective hydroxide. The distribution of the cations between solution and pH-independent exchange sites could be represented satisfactorily by an equilibrium distribution equation when the monovalent ions were NH4 or K but not when they were Li. The ion product (Al) (OH)3 was smaller at low base saturation, and increased to about 10−33.0 with NH4 and K but to only 10−33.7 with Li. The monovalent base potential (pH–pM) was a function of the magnitude of (Al) (OH)3 and the distribution constant, as well as the degree of base saturation.

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