Mixture Of LiNO3 Research Articles

A Novel LiNO3-Based Eutectic Salt Mixture for Industrial Heat Treatment

Abstract A potassium nitrate–lithium nitrate–sodium nitrate (KNO3-LiNO3-NaNO3) eutectic mixture having a low melting point has been proposed as an alternative high-temperature quench medium. Inconel and steel probes were used to compare the quench performance of a conventional sodium nitrite (NaNO2) eutectic mixture and the proposed alternative medium at different bath temperatures. For the Inconel probe, the heat extraction rate was higher in the eutectic LiNO3 mixture maintained at 150°C. At elevated bath temperatures of 200°C, 250°C, and 300°C, the heat extraction rate was higher in the eutectic NaNO2 mixture. AISI 52100 steel probes quenched in eutectic LiNO3 quench medium at 150°C and 200°C showed higher hardness. At bath temperatures of 250°C and 300°C, the hardness of AISI 4140 steel probes quenched in both media was comparable. Wettability studies on Inconel and steel surfaces revealed the occurrence of nonuniform dilation of a LiNO3 eutectic mixture droplet. On the steel surface, the phenomenon occurred at lower temperatures, which resulted in an extended boiling stage and increased hardness.

Adapting the MgO-CO2 Working Pair for Thermochemical Energy Storage by Doping with Salts: Effect of the (LiK)NO3 Content

The MgO-CO2 working pair has been regarded as prospective for thermochemical energy storage (TCES) due to its relatively high heat storage capacity, low cost, and wide availability. This study is aimed at the optimization of the molar salt content, α, for the MgO modified with the eutectic mixture of LiNO3 and KNO3 (Li0.42K0.58NO3) which was earlier shown to provide high conversion, Δx, in heat-storage/release processes at 300–400 °C. The composites that have different salt content were prepared and carbonation kinetics was investigated under various conditions (carbonation temperature, Tcarb., is 290–360 °C and CO2 pressure, P(CO2), is 50–101 kPa). Significant accelerating effect was revealed at α ≥ 0.05, and the Δx value was maximized at α = 0.10–0.20. The largest conversion of 0.70 was detected at α = 0.10 and Tcarb. = 350 °C that corresponds to the specific useful heat (Qcomp.) is 1.63 MJ/kg-composite. However, the salt content of 0.20 ensures the high conversion, Δx = 0.63–0.67 and Qcomp. = 1.18–1.25 MJ/kg-composite in the whole temperature range between 290 and 350 °C. The (LiK)NO3/MgO composite with an optimal salt content of 0.20 exhibits reasonable durability through cyclic experiment at 330 °C, namely, the stabilized reacted conversion Δx = 0.34 (Qcomp. = 0.64 MJ/kg-composite). The studied (Li0.42K0.58)NO3 promoted MgO-CO2 working pair has good potential as thermochemical storage material of middle temperature heat (300–400 °C).

Boiling Heat Transfer Coefficients in a Falling Film Helical Coil Heat Exchanger for the NH3–LiNO3 Mixture

This paper reports the experimental data of boiling heat transfer coefficients for the ammonia–lithium nitrate mixture in a laminar falling film. The analyzed heat exchanger consists of a shell with an internal helical coil. More than one hundred test runs were carried out in steady-state conditions to determine the boiling heat transfer coefficients at generation temperatures, concentrations, and mass flow rates typical of absorption cooling systems of capacities between 5 and 10 kW. Ammonia vapor was produced at generation temperatures between 80 °C and 105 °C obtaining boiling heat transfer coefficients between 85 and 340 W/m2K. Semi-empirical correlations were used by diverse authors to correlate the experimental data. A new correlation was proposed with which the best adjustments were obtained. Also, the influence of the heat flux, the refrigerant solution mass flow rates, and the exit vapor qualities were analyzed in the boiling heat transfer coefficients.

Molten Salt Synthesis of Bi2WO6 Powders and its Visible-Light Photocatalytic Activity

Bi2WO6 powders were synthesized by the molten salt method at 250-350 oC using the mixture of Bi(NO3)3·5H2O and Na2WO4·2H2O as a precursor, and the mixture of LiNO3 and NaNO3 with a molar ratio of 27:33 as a molten salt, respectively. The effects of temperature and salt amount on the phase composition, morphology and photocatalytic activity under the visible light irradiation were investigated. The results revealed that pure phase Bi2WO6 powders could be synthesized at 350 oC as the weight of molten salts were 2‒5 times as many as the precursor. Bi2WO6 powder synthesized with lower salt amount exhibited larger surface area, more abundant pores, narrower bandgap and lower PL intensity, all of which contributed a higher photocatalytic activity. The synthesized Bi2WO6 powder could degrade 0.01 mol/L Rhodamine-B solution by 97% after irradiation under visible light for 60 min. The obtained Bi2WO6 powder had a good photochemical stability and reusability, revealing potential application in environmental treatment.

CO2 absorption properties of lithium sodium orthosilicate in the presence of water vapor at room temperature

We discovered that water vapor enhanced the CO2 absorption capacity of sodium orthosilicate (Li3NaSiO4) at as low as room temperature (RT) and the CO2 absorption property of Li3NaSiO4 in the presence of water vapor was larger than that of Li3NaSiO4 under a dry CO2 flow at high temperatures. Li3NaSiO4 powders were synthesized by heating a mixture of LiNO3, NaNO3, and amorphous SiO2 at 800 °C for 5 h in air. Thermogravimetry analysis shows that CO2 absorption of Li3NaSiO4, at RT, increased as a function of relative humidity and CO2 concentration. CO2 absorption of Li3NaSiO4 in the presence of water vapor resulted in the formation of NaHCO3 and Li2SiO3, as observed by X-ray diffraction (XRD), whereas >300 °C, Li3NaSiO4 reacted with CO2 to produce LiNaCO3 and Li2SiO3 under a dry CO2 flow. The CO2 absorption capacity of Li3NaSiO4, at RT, was enhanced in the presence of water vapor compared with Li3NaSiO4 under a dry CO2 flow at high temperatures. XRD determined that Li3NaSiO4 was regenerated by the heat treatment of the CO2-absorbed Li3NaSiO4 at 600 °C.

CO2 absorption property of Li4SiO4 in the presence of water vapor at room temperature

Lithium orthosilicate (Li4SiO4) powders were synthesized by heating a mixture of LiNO3 and amorphous SiO2 at 800 °C for 5 h in air. The formed powders were applied to capture CO2 in the presence of water vapor at room temperature (RT). Thermogravimetric (TG) analysis showed that the CO2 absorption reaction of Li4SiO4 was promoted even at RT as the relative humidity increased, whereas little absorption occurred under a dry CO2 flow. X-ray diffraction measurements, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy clarified that an amorphous phase and Li2CO3 were produced on the Li4SiO4 surface after the CO2 reaction in the presence of water vapor. The adsorption of water vapor resulted in the formation of a basic solution on the surface of Li4SiO4 particles. This solution promoted CO2 absorption to Li4SiO4 even at RT. As a result, the CO2 absorption capacity of Li4SiO4 in the presence of water vapor at RT was greater than that of Li4SiO4 in the presence of dry CO2. Gas chromatography and TG revealed that the Li4SiO4 absorbed CO2 in the presence of water vapor and released CO2 over two temperature regions, namely a region below 500 °C and one above 600 °C. The single phase of Li4SiO4 was regenerated by heating the CO2-absorbed Li4SiO4 at 700 °C.

Combined Modification of Dual-Phase Li4Ti5O12-TiO2 by Lithium Zirconates to Optimize Rate Capabilities and Cyclability.

The low electrical conductivity and ordinary lithium-ion transfer capability of Li4Ti5O12 restrict its application to some degree. In this work, dual-phase Li4Ti5O12-TiO2 (LTOT) was modified by composite zirconates of Li2ZrO3, Li6Zr2O7 (LZO) to boost the rate capabilities and cyclability. When the homogeneous mixture of LiNO3, Zr(NO3)4·5H2O and LTOT was roasted at 700 °C for 5 h, the obtained composite achieved a superior reversible capacity of 183.2 mAh g-1 to the pure Li4Ti5O12 after cycling at 100 mA g-1 for 100 times due to the existence of a scrap of TiO2. Meanwhile, when the composite was cycled by consecutively doubling the current density between 100 and 1600 mA g-1, the corresponding reversible capacities are 183.2, 179.1, 176.5, 173.3, and 169.3 mAh g-1, signifying the prominent rate capabilities. Even undergoing 1400 charge/discharge cycles at 500 mA g-1, a reversible capacity of 144.7 mAh g-1 was still attained, denoting splendid cyclability. From a series of comparative experiments and systematic characterizations, the formation of LZO meliorated both the Li+ migration kinetics and electrical conductivity on account of the concomitant superficial Zr4+ doping, responsible for the comprehensive elevation of the electrochemical performance.

Improvement of the corrosion properties in ternary molten nitrate salts for direct energy storage in CSP plants

The corrosive effects of a molten nitrate mixture composed by 20% LiNO3+28% NaNO3+52% KNO3 were appraised at 390°C on a low-Cr alloy steel (T22) and a carbon steel (A1). The corrosion rates were determined using gravimetric analysis, which measures the weight gain over 2000h in order to identify the corrosion products with scanning electron microscopy (SEM) and X-ray diffraction (XRD).The observed behavior was compared with the corrosion ability produced by 58% KNO3+11% Ca(NO3)2+31% LiNO3 mixture. The results shown improved behavior in the ternary molten salt with calcium nitrate content due to the reduction of chloride ion levels and the superior diffusion and formation of protective spinels, such as MgCr2O4 and FeCr2O4, which were detected in ternary molten salt with Ca(NO3)2 content.The formation of certain stable compounds with salt impurities, such as carbonates and sulfates, was also observed.

ChemInform Abstract: Synthesis and Electrochemical Properties of Spinel Li(Li0.05Cu0.05Mn1.90)O4 by a Flameless Combustion Method.

AbstractThe title material is prepared by a flameless combustion method from a stoichiometric mixture of LiNO3, LiOAc, Mn(NO3)2, Mn(OAc)2, and Cu(NO3)2 (500 °C, 3 h) followed by calcination (700 °C, 6 h).

Kinetic Studies on the Synthesis of Monoclinic Li3V2(PO4)3 via Solid-State Reaction.

The data obtained by thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (XRD) measurements of the stoichiometric mixture of LiNO3, NH4VO3, and NH4H2PO4 were analyzed by both the Flynn-Wall-Ozawa (FWO) and Friedman-Reich-Levi (FRL) methods. The whole solid state reaction process could be divided into four stages corresponding to α values of 0.03-0.20, 0.30-0.60, 0.70-0.80, and 0.90-0.99. The nucleation of LiVP2O7 (α = 0.70-0.80) is a determining step of the four-reaction processes, for which the mechanism of random nucleation and subsequent growth, described by the Avrami-Erofeev equation (n = 4) G(α) = [-ln(1-α)]4, was assumed. Moreover, the Gibbs free energy of activation ΔG*, enthalpy of activation ΔH*, and entropy of activation ΔS* at maximum temperature of the peak for the determining step were 99.24 kJ·mol-1, 199.97 kJ·mol-1, and 136.30 J·mol-1·K-1, respectively. Finally, XRD analyses confirmed that the Li3V2(PO4)3 synthesized by the precursor route is a pure phase.

Comparison of the performance of single-effect, half-effect, double-effect in series and inverse and triple-effect absorption cooling systems operating with the NH3–LiNO3 mixture

This paper presents the performance comparison of five different configurations of absorption cooling systems operating with ammonia–lithium nitrate. The configurations are: i) single-effect, ii) half-effect, iii) double-effect in series, iv) double-effect inverse and v) triple-effect. Mathematical models were developed for each one of the systems. Coefficients of performance are reported for the systems as function of their main operating temperatures, such as: generation, absorption, condensation, and evaporation. The results showed that the lowest evaporator temperatures can be achieved with half-effect systems at the lowest generator temperatures with coefficients of performance around 0.3. The single-effect system is the simplest configuration since it requires fewer components in comparison to the other systems. Its coefficients of performance are almost twice higher than those obtained with half-effect systems but requiring higher generator temperatures. With double-effect systems it is possible to obtain coefficients of performance as high as 1.12 at condenser temperatures of 30 °C but they need generator temperatures higher than 140 °C to reach evaporator temperatures as low as −5 °C. The highest coefficients of performance can be achieved with triple-effect systems but they are the most complex, they require the highest generator temperatures and they should be mainly used for air conditioning.

ChemInform Abstract: Li0.5Al0.5Mg2(MoO4)3.

AbstractThe title compound is prepared by solid state reaction of a stoichiometric mixture of LiNO3, (NH4)2Mo4O13, and Mg(NO3)2 (porcelain crucible, 853 K, 7 d).

Preparation and Mechanism of Spherical [Ni1/3Co1/3Mn1/3]Ox Precursors for Li [Ni1/3Co1/3Mn1/3]O2 by an Ultrasonic Atomization Method

The spherical precursors - [Ni1/3Co1/3Mn1/3]Ox and Li [Ni1/3Co1/3Mn1/3]O2 were synthesized by an ultrasonic atomization method via two routes. The [Ni1/3Co1/3Mn1/3]Ox and Li [Ni1/3Co1/3Mn1/3]O2 powders were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results show that the initial concentration of the raw solution would affect the size of precursor [Ni1/3Co1/3Mn1/3]Ox particles. The Li [Ni1/3Co1/3Mn1/3]O2 particles which were prepared from the mixture of LiNO3 and [Ni1/3Co1/3Mn1/3]Ox were much larger than the precursor particles and those prepared from the LiNO3-[Ni1/3Co1/3Mn1/3]Ox may maintain the size of the precursor particles.

ChemInform Abstract: Synthesis, Structural Characterization and High Pressure Phase Transitions of Monolithium Hydronium Sulfate.

Abstract(H3O)LiSO4 is solvothermally synthesized from a mixture of LiNO3, 1,5‐naphthalenedisulfonic acid tetrahydrate, and NH4F dissolved in DMF (autoclave, 100 °C, 4 d, 50% yield).

Energy analysis of a diffusion absorption cooling system using lithium nitrate, sodium thiocyanate and water as absorbent substances and ammonia as the refrigerant

A diffusion absorption cooling system is analyzed to determine the appropriate fluid for the unit, based on the coefficient of performance (COP) and operating conditions, by comparing lithium nitrate (LiNO3), sodium thiocyanate (NaSCN) and water (H2O) as absorbent substances and by using ammonia (NH3) as the refrigerant. The presence of crystallization in the system is analyzed as a function of the generator and absorber temperatures. Additionally, the effects on the efficiency of the system from adding the inert gas helium (He) or hydrogen (H2) are studied. A mathematical model is developed and compared to experimental studies reported in the literature. At an evaporator temperature of −15 °C, a generator temperature of 120 °C and absorber and condenser temperatures of 40 °C, the results show that the best performance is achieved by the NH3–LiNO3–He mixture, with a COP of 0.48. This mixture performs 27–46% more efficient than the NH3–NaSCN mixture. The NH3–H2O mixture is 52–69% less efficient than the NH3–LiNO3 mixture. However, when the evaporator runs at 7.5 °C, the NH3–H2O–He mixture achieves a more efficient COP than does the NH3–LiNO3–He mixture, and the NH3–NaSCN–He and NH3–LiNO3–He mixtures achieve the same COP when the evaporator is at 10 °C. At temperatures below 7.5 °C, the NH3–NaSCN–He mixture achieves a higher COP than does the NH3–H2O–He mixture. The NH3–LiNO3 mixture shows crystallization at higher temperatures in the generator than does the NH3–NaSCN mixture. Moreover, at the same evaporator temperature, the NH3–LiNO3 mixture works at activation temperatures lower than does the NH3–NaSCN mixture.

A simple one-step synthesis of ZnS nanoparticles via salt-alkali-composited-mediated method and investigation on their comparative photocatalytic activity

ZnS nanoparticles have been successfully synthesized via salt-alkali-composited-mediated method (SACM) for the first time, using a mixture of LiNO3 and LiOH (LiNO3/LiOH=60.7:39.3) as a reaction solvent, sodium sulfide and zinc nitrate as reactants at temperature of 210°C for 24h in the absence of organic dispersant or capping agents. X-ray diffraction, environment scanning electron microscopy (ESEM) and Transmission electron microscopy (TEM) indicated that the as-synthesized products were well crystallized and belonged to nano-scale. Their UV–vis absorption spectrum demonstrated a band gap of 3.6406eV corresponding to the absorption edge of 340nm. The experimental result of photocatalytic degradation on methyl orange by the nano-ZnS showed much better photocatalysis than that by the commercial ZnS powder under the irradiation of ultraviolet light and visible light, respectively.

Novel fast and easy growth of highly crystalline, idiomorphic fluorapatite crystals via an atmospheric pressure plasma-assisted flux coating method

Idiomorphic and one-dimensional (1-D) Ca5F(PO4)3 (fluorapatite, FAp) crystals were successfully, directly, and densely grown on silicon and poly(ethylene terephthalate) (PET) substrates via an atmospheric pressure plasma-assisted flux coating (APP-FC) method. To achieve a low-temperature crystal growth, a KNO3–LiNO3 mixture was chosen as the flux.

Preparation and electrochemical characteristics of a new Li-Mn-V-O system formed from heat-treatment of a MnO2, NH4VO3 and LiNO3 mixture

New quarternary oxides (Li2O) x · MnO2 · yV2O5 (x = 0.125 ∼ 0.25, y = 0.125 ∼ 0.25), formed by heating mixtures of MnO2, NH4VO3 and LiNO3 at various Li/Mn and V/Mn atomic ratios and at different temperatures (300 ∼ 400 °C in air, have been characterized by X-ray diffraction, X-ray photoelectron spectroscopy (ESCA) and infrared spectroscopy. The quarternary oxide with x = 0.25 and y = 0.25 showed a discharge capacity of 220 A h (kg oxide)−1 and an energy density of ca. 600 W h (kg oxide)−1 at a current density of 0.20 mA cm−1 in 1 m LiClO4-propylene carbonate at 25 °C. When charge-discharge cycling with the (Li2O) · MnO2 · 0.25V2O5 electrode was performed at a constant capacity of 30 A h (kg oxide)−1 and at a constant current density of 0.10 0.20 mA cm−2, the electrode sustained over 100 cycles at a high mean discharge potential of ca. 3 V vs Li/Li+.