Electrical Conductivity Of Electrolyte Research Articles

Intelligent Electrometric Device for Dental Caries Diagnosis

The article deals with the development of a medical device for high-precision measurement and automatic diagnosis of dental caries stage. The analysis of the composition and characteristics of tooth hard tissues, being the cause of caries and its development, is given. It has been established that the main cause of the carious process is the attack of acid-forming bacteria on tooth enamel. It is shown that the most promising method for caries diagnosis is the electrometric method, which consists in measuring electrical conductivity of the tooth hard tissue electrolyte. Conventional devices for the electrometric method implementation are described, using the direct current through the biological tissue of the tooth, but not taking into account the electrochemical features of the current flow. An electrochemical interpretation of the current flow through biological tissues and two electrodes with a polarity switch of these electrodes was performed, which makes it possible to exclude the effect of polarization of biological tissue and electrodes both for teeth in vivo and in vitro. An equivalent diagram of the current flow through the biological tissue is given, which value can reveal the stage of the carious process: intact enamel, pre-carious state, initial, superficial, medium and deep caries. The use of two current-carrying electrodes for measuring the electrical conductivity of biological tissues is considered: an active electrode made of stainless steel using a 10% solution of CaCl2 and a passive electrode also made of stainless steel and using an electrolyte of the biological tissue of a tooth (simulated by a 0.9% solution of NaCl). A comparative assessment of the tooth biological tissue electrolyte electrical conductivity and electrical conductivity of the active and passive electrode electrolytes was performed to assess the error of the electrometric method. A high-precision intelligent electrometric device (protected by a patent for an invention) has been developed, which allows automatic carious process stage determination by the value of the tooth biological tissue electrical conductivity; the operation of this device is described.

Microstructural Analysis of Effective Electrode Conductivity in Molten Salt, Na-ZnCl2 Batteries

Intermediate temperature molten salt batteries are a promising alternative for grid-scale energy storage with several advantages over existing solutions. The cathode of some of these batteries is composed of a porous matrix of materials containing the metal backbone of the electrode, along with electrolyte components that vary and different locations or as the state of charge of the battery changes. In this work, we aim to analyze the influence of the microstructural properties of the cathodic region at different compositions for a Na-Zn (ZnCl2) battery. Synthetic geometric models of the electrode at different compositions are generated and then the effective conductivity is estimated through numerical simulation of the current and potential distribution through the material. At a three-phase composition used by a typical electrode assembly, the effective conductivity is approximately three times larger than the electrolyte electrical conductivity.

Study reaction kinetics of fuel model desulfurization by electrochemical oxidation technique

The model fuel (Heptane contained 2500 ppm from DBT) was desulfurized electrochemically at a constant current (300 mA), in which the process consists two steps; the first step is electrochemical desulfurization by using an electrochemical cell contains two graphite electrodes immersed in electrochemical cell; the cell contains model fuel, hydrogen peroxide as oxidation agent, 0.106 M is NaCl to enhance electrolyte electrical conductivity. The investigation was at different operation parameters; temperature range (40-50-60 °C), stirring time (10-20-30-40-50) min, while the second step is extraction with acetonitrile. The results show final sulfur concentration decreased when increasing time at the same temperature for example. Kinetics parameters calculation shows that electrochemical desulfurization ECD reaction follows pseudo 1st order reaction, the rates constant of reaction are 0.0175, 0.0191 and, 0.0193 at temperatures 40, 50, and 60 °C, respectively, while activation energy equal 4.433 kJ/mol.

Using Box-Behnken experimental design for optimization of gas oil desulfurization by electrochemical oxidation technique

Iraqi gas oil with sulfur content 9400 ppm was desulfurized electrochemically at constant current (300 mA), the process consists two steps; first step is electrochemical desulfurization by using electrochemical cell contains two graphite electrodes while the used electrolyte is NaCl to enhance electrolyte electrical conductivity, and hydrogen peroxide as an oxidant agent, second step is extraction with acetonitrile. Optimization of process parameters was done by applying response surface methodology RSM combined with Box –Behnken experimental method, in which the sulfur removal efficiency was acted as response function while the reaction temperature, NaCl concentration and time were selected as controllable (studied) variables. The sulfur removal efficiency was ranged from 55.84 % to 88.07%. The results were analyzed with Design-Expert software by fitting with second order polynomial model and the empirical model was exhibited high correlation factor (R2=0.9966) and the estimated optimization solution stated that maximum sulfur removal efficiency is 88.611% at temperature (57.656 °C), NaCl concentration (0.106 M) and, time (51.46 min.).

Facile synthesis and performance of NASICON Li1+xAlxGe2-x(PO4)3 electrolytes for all solid state lithium-ion battery

Nasicon-type Li1+xAlxGe2-x(PO4)3 (x = 0–0.5) electrolytes have been prepared via a facile and economic method. All synthetic electrolyte samples show Nasicon structure and good crystallinity. The Al doping content has a great influence on the electrical conductivity of electrolyte. The electrolyte with the composition of Li1.4Al0.4Ge1.6(PO4)3 exhibits a highest electrical conductivity of 2.72 × 10−4 S/cm at room temperature, which is mainly attributable to fewer impurity and dense electrolyte structure. The LiFePO4/Li cell assembled with this electrolyte delivers an initial specific discharge capacity of 127.86 mAh g−1 at a charge/discharge current density of 0.5C at 60 °C, which shows an excellent cycling performance with high discharge capacity of 131.2 mAhg−1 after 150 cycles. These results suggest that the Li1.4Al0.4Ge1.6(PO4)3 electrolyte is a potential electrolyte for all solid state lithium-ion battery.

Heavy metal removal effectiveness, flow direction and speciation variations in the sludge during the biosurfactant-enhanced electrokinetic remediation

Heavy metal high content is strictly limited the land application of the sludge, which is considered as the best way for resource utilization. Hence, it is essential to explore a more effective way for reducing toxic metal. In this work, the combined biosurfactant and electrokinetic technique was used to promote toxic metals removal. Electroosmotic flow (EOF), sludge water content, electrolyte and sludge electrical conductivity variations, and removal efficiency, distribution, speciation and binding intensity of heavy metal variations were investigated during the electrokinetic process. The results demonstrated that the combined biosurfactant with electrokinetic technique could enhance toxic metals removal from sludge. In the enhanced electrokinetic treatment, the combined biosurfactant with electrokinetic technique can enhance cumulative electroosmotic flow, and the electrolyte electrical conductivity of anode and cathode, and the EK3 obtained a higher electrical conductivity (EC) than other EK treatments. Heavy metals obtained the highest removal efficiency during the EK3 treatment. Heavy metals distribution demonstrated that 58.63%, 71.34%, 63.04%, 52.95%, 61.74%, 56.24% of copper, zinc, chromium, lead, nickel and manganese migrated into the electrode solution, respectively, and 38.02%, 26.20%, 32.54%, 42.69%, 36.34%, 42.35% of copper, zinc, chromium, lead, nickel and manganese were still remained in the sludge. Heavy metal speciation indicated that the labile speciation percentage decreased. Whereas, the stable speciation percentage increased after the electrokinetic treatments. Heavy metal stability demonstrated that binding intensity increased, due to heavy metal have a higher stable speciation after the electrokinetic treatments.

Многокомпонентные неводные электролиты для работы суперконденсаторов при повышенных температурах

Multicomponent non-aqueous electrolytes based on cyclic carbonates and tetraethylammonium tetrafluoroborate have been developed for the operation of supercapacitors at elevated temperatures. Propylene carbonate, which has a high dielectric constant and a high boiling point, was used as the main solvent of electrolytes. However, a significant drawback of propylene carbonate is its high viscosity, which leads to decrease in the electrical conductivity of electrolytes based on it compared to electrolytes based on acetonitrile. To increase the electrical conductivity, an additional component was introduced into the electrolyte – a cosolvent with the necessary set of properties. When choosing cosolvents, two approaches were used. In the first case, to increase the dielectric permittivity of the liquid phase, ethylene carbonate having a higher dielectric constant than propylene carbonate was introduced into the electrolyte. This approach made it possible to significantly increase the electrical conductivity of the electrolyte and to achieve high resource stability of the supercapacitor. The values of the specific capacitance and energy of the supercapacitor with the introduction of ethylene carbonate in the electrolyte practically did not change. In the second case, butyl acetate, which has a low viscosity but has a moderate polarity and a sufficiently high boiling point, was used as a co-solvent. In this case, not only an increase in the electrical conductivity of the electrolyte was observed, but also a significant increase in the capacitive characteristics of the supercapacitor. It is shown that the use of a mixture of cyclic carbonates and esters as a solvent in the composition of the electrolyte can increase its specific conductivity by 40%, and the specific energy consumption of a supercapacitor by 20%. The developed electrolytes provide long-term operation of supercapacitors both at room temperature and at elevated temperatures up to 80 °С.

Measurement of Electrical Resistance of Liquid Electrolytes and Materials Containing Them

Measurement of the electrical conductivity of electrolytes and heterogeneous materials containing them is accompanied by numerous physical and electrochemical processes, complicating measuring and interpretation of data. As a result, the measurement of the electrical conductivity of such a system is a difficult and not finally resolved problem. The new method of resistance measurement of the electrolytic systems is substantiated and tested on example of heterogeneous electrolytic system “lignin-calcium chloride water solution” in this article. The method is based on measurement of resistance of the electrolytic system at different voltages (DC) on the cell and the consequent approximation of the acquired data taking into consideration volume charges and potential barriers arising on the boarders of electrodes and electrolytic materials. Extrapolation of the resistance to the limiting small current lets one obtain a characteristic value of the active resistance of the electrolytic system. The method is technically simple, inexpensive and has several advantages compared to the methods based on AC measurements.

Synthesis and investigation on stability and electrical conductivity of Ti-doped Ba3CaTa2-xTixO9 (0 ≤ x ≤ 1.0) complex oxides

An attempt has been made here to synthesize Ba3CaTa2-xTixO9 (0 ≤ x ≤ 1.0) perovskite-type complex oxides and characterize with regard to structure, chemical stability and conductivity to develop electrolytes for proton conducting fuel cells. X-ray diffraction pattern shows the formation of single phase of double perovskite-type structure with lattice parameter lies in the range of 8.368–8.393 Å (±0.004 Å) for x = 0–0.50 and decreases with titanium content (x). Fourier transform infrared spectra and X-ray diffraction data confirm improved stability of Ba3CaTa2-xTixO9 (0 ≤ x ≤ 0.5) in humid air (H2O exposed) and CO2 atmosphere at elevated temperatures. X-ray photoelectron spectra attributed to the presence of Ti3+ and Ti4+, bonding between Ba-O and O - (Ti/Ta). The electrical conductivity of electrolytes are analyzed in different atmospheres e.g., dry and wet air and argon. There is increase in conductivity in wet atmospheres, confirmed the proton conduction in Ba3CaTa2-xTixO9 (0 ≤ x ≤ 0.5). Among Ti-substituted materials, Ba3CaTa1.5Ti0.5O9 shows the highest conductivity.

Influence of the soil electrical conductivity in the area of the underground pipeline on energy efficiency of the cathodic protection

In this paper we consider main factors which have an influence on energy efficiency of the cathodic protection and analyze them. Cathodic protection is defined as the ratio of the electrical conductivity of electrolyte, which surrounds the underground (underwater) metal construction (pipeline) and its polarization resistance. The obtained results are correct first of all for the case of presence of modern qualitative insulation, which possess high dielectric properties and is made of, for example, polymers or its’ composition and is meant to be used for protection against electrochemical corrosion of the underground pipelines

Comparative Laboratory Tests of Methanesulfonate and Sulfamic Tinplate Tinning Electrolytes

Comparative tests are performed under laboratory conditions in units modeling existing electrolytic tinning units for contemporary ecologically clean tinning electrolytes based on methanesulfonate (Niveostan 200 version) and sulfamic acids. The main comparison criteria are: adaptability (the range of tolerance for the main parameters); hydrolysis stability and the level of sludge formation; tinned coating qualitative properties. It is shown that both types of electrolytes meet the specifications laid down for tinplate industrial tinning electrolytes and make it possible to prepare high quality anticorrosion coatings over a wide temperature range from 30 to 60°C, and they may provide good electrolytic efficiency (tin current efficiency 95%) with sensible limitation of the current density limit. Sulfamic electrolyte provides a broader range of variation in current density. Methanesulfonate electrolyte without admixture of iron is hardly prone to sludge formation. With an identical iron content (10 g/liter), both electrolytes have about the same low level of tin loss in sludge, but the anticipated rate of iron accumulation is greater in methanesulfonate electrolyte. The main advantage of methanesulfonate tinning is the high electrolyte electrical conductivity making it possible to reduce electrical energy consumption. Maximum use of the technical possibilities of both types of electrolyte is possible in new tinning lines planned and constructed in accordance with features of the production processes used.

A comprehensive analysis of three-phase electrolyte conductivity during electrochemical macromachining/micromachining

Electrolyte electrical conductivity plays a vital role as a process parameter during electrochemical macromachining as well as micromachining, especially during anode shape prediction and tool design. Electrolyte electrical conductivity during electrochemical machining varies due to generation of gas bubbles at the tool and workpiece surfaces, sludge due to the dissolution of workpiece material, and heat due to the flow of electric current in the circuit. The electrolyte becomes a multiphase system. A mathematical model to predict the electrolyte electrical conductivity in the multiphase system is presented in this article. An experimental study has also been carried out to validate the proposed model. This model has been applied to study the variation in electrolyte electrical conductivity along the electrolyte flow direction during electrochemical micromachining by measuring change in workpiece thickness. Optimum input machining parameters are also presented at which the change in electrolyte conductivity is negligible in the machining zone.

Influence of Concentrations of KOH and Na2SiO3 Electrolytes on the Electrochemical Behavior of Ceramic Coatings on 6061 Al Alloy Processed by Plasma Electrolytic Oxidation

In this study, ceramic coatings were deposited on 6061 Al alloy using a plasma electrolytic oxidation (PEO) technique, and the effect of concentrations of KOH and Na2SiO3 as electrolytes for PEO process was studied on microstructure, chemical composition, and electrochemical behavior of PEO coatings formed on the 6061 Al alloy. The results indicated that the increase in concentration of KOH led to rise in electrical conductivity of electrolyte. Consequently, the breakdown voltage reduced, which in turn improved the surface quality and the corrosion behavior. Moreover, the increase in concentration of Na2SiO3 resulted in the increase in incorporation of Si in the coating, which led to a higher corrosion potential in the concentration of 4 g L−1. According to this investigation, the best protection behavior of coatings can be obtained when the KOH and Na2SiO3 concentrations in PEO electrolyte are equal to 4 g L−1.

CONCEPTUAL MODEL OF COMMUTATION MECHANISM FOR ELECTRIC CONDUCTIVITY OF VAPOR-GAS ENVELOPE IN ELECTRO-IMPULSE POLISHING MODE

Electric conductivity of vapor-gas envelope in electro-impulse polishing mode is closely connected with mechanisms of physical and chemical processes occurring on an anode surface and in pre-anode area of electrolyte, metal removing, smoothing-out of surface profile irregularities and technological regimes influencing on productivity and processing accuracy. The paper presents experimentally substantiated conceptual model of a mechanism for electric conductivity of vapor-gas envelope. According to the model an electric current passing in the envelope and having quasi-constant and high-frequency components is provided by ionic conductivity in electrolyte envelope-enclosing bridges and ionic conductivity in gas envelope phase. It has been shown that quasi-constant of the current component represents a composition of electric current consisting of overlapping time current impulses from electrolyte bridges that enclose the envelope with frequency of 0.01−0.90 kHz and current in a gas phase of the envelope. High-frequency current component is pre-conditioned by ionic conductivity in bridges that commutate the envelope with frequency of 2.5 MHz. The paper theoretically substantiates excessive electrical conductivity of electrolyte in the electrolyte bridges. It has been demonstrated that formation of vapor-gas envelope and its renovation are connected with thermal burst mechanism for destruction of electrolyte bridges. Envelope vibration and hydrodynamic flows within the electrolyte occur due to impulse wave impact on electrolyte layer which is on the border of the envelope. The waves are caused by burtsts of electrolyte bridges and cavitation bubble collapse in pre-anode electrolyte area.

Specific electrical conductivity of chromium plating and nickel plating electrolytes

The paper presents the results of measuring specific electrical conductivity (SEC) of chromium and nickel plating electrolytes with the help of a non-contacting conductivity meter of the CRAB-d 064 type in temperature intervals corresponding to the working ranges of electrochemical deposition processes. A schematic diagram of the apparatus for the measurement of electrolyte SEC is presented. Electrolytes based on chromium compounds of varying degrees of valence (Cr3+ Cr6 +) and a standard nickel electrolyte (Watts electrolyte) were chosen as the objects of study. The dependence of the SEC of electrolytes on their temperature is analyzed, a comparative assessment of the impact of temperature on the electrical conductivity of various chroming electrolytes is given.
 The influence of addition of nanoparticles of aluminum oxide and silicon carbide with the dispersion of 40-100 nm and a specific surface area of 23-32 m2 / g on the amount of electrical conductivity of an oxalate-sulfate electrolyte for chromium plating at a specified temperature is investigated. The study of nanosuspensions showed that the addition of nanoparticles of different nature with the concentration of 5-10 g / l to an electrolyte has no significant effect on the value of SEC.
 To evaluate the relationship between the electrolyte conductivity and process parameters of electrodeposition of chromium and nickel coatings a qualitative assessment of chromium and nickel current output was performed and bar graphs showing the ratio of the values of the electrolyte electrical conductivity and the metal current output are presented. It has been established that the electrical conductivity of electrolytes and the metal current output are parameters that do not depend on each other.

Improving machining accuracy in wire electrochemical micromachining using a rotary helical electrode

Wire electrochemical micromachining (WECMM) is becoming more important in fabricating complex microstructures. The machining accuracy of WECMM is usually evaluated by the interelectrode gap width. Faster electrolyte refreshment increases the uniformity of the electrolyte electrical conductivity distribution in the machining gap, the machining stability and the machining accuracy. We propose a method of WECMM using a rotary helical electrode that improves the machining accuracy by increasing the electrolyte refreshment and achieving a faster electrode feed rate and consequently decreasing the machining gap. Simulations of the electric field indicated that the current density was localized for the rotary helical electrode. Experiments verified that the rotary helical electrode decreased the machining gap from 94 to 19 μm compared with a cylindrical electrode of the same diameter. In addition, the effects of the process parameters on the interelectrode gap width were experimentally investigated. Finally, using optimal parameters, two precision microstructures with clean-cut edges were fabricated.

Effect of KOH Concentration on the Microstructure and Electrochemical Properties of MAO-Coated Mg Alloy AZ31B

In this study, the effect of KOH concentration on the electrochemical properties of micro-arc oxidation (MAO) coated Mg alloy AZ31B has been investigated. Also, the surface morphology and chemical composition of the MAO coatings have been characterized by scanning electron microscopy and x-ray diffraction. In MAO process, an increase in the concentration of KOH as a result of increase in the electrolyte electrical conductivity leads to a reduction in sparking which in turn improves the quality and the behavior of anodic coatings in the concentration of 2.5 M. Moreover, it can be concluded that the MAO coating shows its best protective behavior when KOH concentration is equal 2.5 M, and if the concentration is higher or lower than this value, the protective properties of MAO coating will decrease.

Temperature sensitivity of nanochannel electrical conductance.

Electrical measurement is a widely used technique for the characterization of nanofluidic devices. The electrical conductivity of electrolytes is known to be dependent on temperature. However, the similarity of the temperature sensitivity of the electrical conductivity for bulk and nanochannels has not been validated. In this work, we present the results from experimental measurements as well as analytical modeling that show the significant difference between bulk and nanoscale. The temperature sensitivity of the electrical conductance of nanochannel is higher at low ionic concentration where the nanofluidic transport is governed by the electrostatic effects from the wall. Neglecting this effect can result in significant errors for high temperature measurements. Additionally, the temperature sensitivity of the nanochannel conductance allows to measure the enthalpy change of surface reactions at low ionic concentrations.

Influence of electrolyte ageing on the Plasma Electrolytic Oxidation of aluminium

The chemical stability of the electrolyte in Plasma Electrolytic Oxidation (PEO) has been the subject of much systematic investigation. The present study reports on experimental results on the ageing of a usual PEO electrolyte and its effect on the oxidation of the Al2214 aluminium alloy. A solution of potassium hydroxide ([KOH]=1gL−1) and sodium silicate ([Na2SiO3]=1.65gL−1) diluted in deionised water was either aged by running a process during 8h at most or not. Comparison between materials treated in either solution was made next. Cross-checked experimental results from analytical chemistry, plasma diagnostics and materials science clearly evidence the effect of ageing of the electrolyte on the PEO process behaviour. The transition from arc to “soft” regime occurs earlier (from 18min to 13min processing time) as the electrolyte gets older. The concomitant decrease in the electrolyte electrical conductivity (from 7.5mScm−1 to 6.8mScm−1) is correlated with changes in the ionic species content in the electrolyte. Fast video-imaging (125kfr/s) reveals that the micro-discharge characteristics are also sensitive since they become less numerous per area and unit time (from 220×103cm−2s−1 to 120×103cm−2s−1), exhibit shorter lifetime and have smaller sizes as the electrolyte ages. SEM observations of the as-grown coatings combined with roughness measures indicate a decrease in coating thickness (~20%) and roughness (~30%) while species from the electrolyte accumulate in the outer porous layer simultaneously with a gradual enrichment in α-Al2O3 phase in the inner compact layer (from 36% to 43%). Finally, within the PEO conditions that were used, it is shown that the ageing phenomenon of the PEO electrolyte starts to influence the process after 2h aged.

Physical-Chemical Properties of Potassium Cryolite-Based Melts Containing KBF4

Recent developments in the field of low-temperature aluminum electrolysis utilizing oxygen-evolving inert anodes prove the efficiency of potassium cryolite-based electrolytes. Such electrolytes give an opportunity to perform electrolysis at temperature below 800 °C. The potassium cryolite-based electrolytes can be used as prospective media for other electrochemical and chemical technological processes including aluminum alloys production. However, the introduction to the electrolytic bath the metal-containing additives along with alumina can result in electrolysis violation. It is a consequence of significant change in electrolyte properties with varied composition. In present work the KBF4impact on the physical-chemical properties of the potassium cryolite-based melts was studied.Liquidus temperature, electrical conductivity, density, alumina solubility in the KF-AlF3 and KF-NaF(15.9 mol%)-AlF3 molten mixtures containing KBF4 were determined. Cryolite ratio (CR), the ratio between molar concentrations of the alkali metal fluoride and aluminum fluoride (CR=NMF/NAlF3), was varied from 1.3 to 1.5. It should be mentioned that the cryolite ratio for the mixed KF-NaF-AlF3 cryolite melts was calculated as CR=(NKF+NNaF)/NAlF3. Elemental composition of the molten mixtures being studied was controlled by ICP analysis and X-ray fluorescence spectroscopy on XRF-1800 (Shimadzu).The liquidus temperature of the cryolite melts was measured by the specially developed thermal analysis technique. The data obtained in the KF-AlF3-KBF4 and KF-NaF(15.9 mol%)-AlF3-KBF4 systems showed that the liquidus temperature rises with the KBF4 content. It should be noted that the NaF, LiF, and CaF2, potential additives to the electrolyte for low-temperature electrolysis, being added to the KF-AlF3 melts with low CR, impact the liquidus temperature the same manner as KBF4.The alumina additions to the potassium cryolite-based melts decrease the liquidus temperature as it is shown in Fig.1. The quasi-binary “cryolite mixture”– alumina phase diagrams are simple eutectics. The KBF4 presence in the KF-NaF-AlF3-Al2O3 electrolytes shifts the eutectic point to the right and increases the alumina solubility in these melts. The eutectic points were found equal to 759 and 761°C at the Al2O3 content 4 and 5 mol%, respectively, in the [KF-NaF(15.9mol%)-AlF3+KBF4 (3mol%)]-Al2O3 and [KF-NaF(15.9 mol%)-AlF3+KBF4(5 mol%)]-Al2O3 mixtures with CR=1.3. The Al2O3addition of 6 mol% to the both electrolytes results in significant rise of the liquidus. The bend point on the cooling curves corresponding to the temperature of primary crystallization was not detected because the beginning temperature of the cooling process in these tests was below the liquidus. The presence of not dissolved deposit at the bottom of crucible at 850 °C was also confirmed by visual observation.The original technique to study the electrical conductivity of aggressive fluoride and oxide-fluoride melts was developed. It consists in combination of two types cells: capillary (BN) and with parallel electrodes (Mo). The resistivity of electrolyte was measured by means of impedancemeter (Zahner electrik IM6E) in a frequency range from 100 Hz to 1 MHz using a signal with amplitude 5 mV/s. The electrical conductivity of the potassium and potassium-sodium cryolites was measured in the capillary-type cell whereas the electrical conductivity of electrolytes with KBF4 and Al2O3additions was studied in the cell with parallel electrodes. The temperature dependence of a cell constant was taken into account that made the electrical conductivity measurements more accurate in a wide temperature range.The density of cryolite melts was measured using the Archimedean method. A platinum sphere suspended with platinum wire and attached to an electronic balance unit (Mettler AT20) was immersed into the electrolyte located in the glassy carbon crucible. The measurements were performed in the temperature range 700-800 °C. The temperature dependence of the Pt sphere volume was considered and determined in the calibration test with FLiNaK (eutectic). The density of the KF-AlF3-KBF4 melts decreases with increasing the KBF4 content. So, the addition of the KBF4 3 mol% reduces the density of the molten mixture on about 5%.