scholarly journals Facile preparation of ZrO2 whiskers by LiF-KCl molten salts synthesis

2021 ◽  
Vol 15 (3) ◽  
pp. 219-225
Author(s):  
Quan Zhang ◽  
Guo Feng ◽  
Feng Jiang ◽  
Jianmin Liu ◽  
Lifeng Miao ◽  
...  
Keyword(s):  
Molten Salt ◽  
Lithium Fluoride ◽  
Slow Rate ◽  
Molten Salts ◽  
Treatment Temperature ◽  
Molten Salt Method ◽  
Monoclinic Zirconia ◽  
Zirconyl Chloride ◽  
Aspect Ratios ◽  
Dissolution And Precipitation

Monoclinic zirconia (ZrO2) whiskers were made via the molten salt method using zirconyl chloride octahydrate (ZrOCl2 ? 8H2O) as zirconium source, potassium chloride (KCl) as molten salt and lithium fluoride (LiF) as a mineraliser. DSC-TG, XRD, FE-SEM, Raman and TEM were performed to study the effects of heat treatment temperature, holding time and heating rate on the synthesis of zirconia whiskers. The results indicate that zirconia whiskers with diameters of 50-80 nm and aspect ratios of 10-30 can be obtained by heating the precursor at slow rate (3?C/min) to 718?C for 1 h and then at faster rate (7?C/min) to 950?C for 3 h. The whiskers have a smooth surface and grow in [001] direction. The key to the ZrO2 whiskers growth is the controlled dissolution and precipitation of the ZrO2 in a LiF-KCl molten salt solution environment.

Low Temperature Preparation of Mullite Whisker via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

2014 ◽  
Vol 936 ◽  
pp. 975-980 ◽  
Author(s):  
Kai Lin Fu ◽  
Wei Hui Jiang ◽  
Guo Feng ◽  
Jian Min Liu ◽  
Qian Wu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Molten Salt ◽  
Sol Gel ◽  
Growth Direction ◽  
Treatment Temperature ◽  
Molten Salt Method ◽  
Low Temperature Preparation ◽  
Sol Gel Process ◽  
Temperature Preparation

Mullite whisker was prepared at low temperature via non-hydrolytic sol-gel (NHSG) process combined with molten salt method. The influence of heat treatment temperature was studied on the morphology and the microstructure of whisker, and its growth mechanism was also described. The results show that the mullite whisker appears at the lowest temperature of 750 °C, and optimized mullite whisker can be prepared at 850 °C with the growth direction of [00, whose diameter is in the range of 170~300 nm with the aspect ratio of >30.

Synthesis of Pure Bi12SiO20 Powder by Molten Salt Method

2012 ◽  
Vol 182-183 ◽  
pp. 52-56
Author(s):  
Jun Que Lu ◽  
Xiu Feng Wang ◽  
Hong Tao Jiang
Keyword(s):  
Particle Size ◽  
Molten Salt ◽  
Molten Salts ◽  
Raw Materials ◽  
Reaction Medium ◽  
Processing Parameters ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Phase

Pure Bi12SiO20powder was successfully prepared by a molten salt method using Bi2O3and SiO2as raw materials and using KCl-K2CO3as flux at 635°C with the heating rate of 5°Cmin-1. The phase composition and microstructure of these products were analyzed by X-ray diffraction and scanning electron microscopy, and the effects of the processing parameters, such as the ratio of Bi2O3/SiO2, calciniation temperature, isothermal time and relative amount of salt, on the composition and particle size were investigated. The results indicated that regardless of changing the ratio of Bi2O3/SiO2, calciniation temperature, isothermal time or relative amount of salt the reaction only yielded Bi12SiO20without Bi2SiO5and Bi4Si3O12. Henceforth, KCl-K2CO3molten salts may be considered as an ideal reaction medium to synthesize pure phase of Bi12SiO20. The particle size of Bi12SiO20phase can be determined by changing the temperature, isothermal time and relative amount of salt.

Zeolite Synthesis Using Sewage Sludge by Molten-Salt Method

2008 ◽  
Vol 569 ◽  
pp. 329-332
Author(s):  
Yeong Seok Yoo ◽  
Kyeong Ho Cheon ◽  
Jae Ik Lee ◽  
Beom Suk Kim ◽  
Woo Seob Shin ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Thermal Treatment ◽  
Molten Salt ◽  
Sodium Hydroxide ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Zeolite Synthesis ◽  
Molten Salt Method ◽  
Synthesis Time ◽  
Zeolitic Materials

This study was conducted to synthesize zeolitic materials using sewage sludge by molten-salt method the effective method was investigate to reduce the thermal treatment time by adding zeolite seed and excessive sodium hydroxide. To synthesis zeolitic materials, sewage sludge was used as Si and Al sources, also Na2SO4 and NaOH were added as stabilizer and mineralizer respectively. Sewage sludge was prepared by calcination at 550°C/3hr to remove organic materials. As a result of thermal treatment at 950°C for 6~24hrs, more than 18 hours was required to synthesize zeolitic materials without adding zeolite seed. On the other hand, it is observed that hydroxyl-sodalite was synthesized in 9 hours thermal treatment and Na-P1 also in 12 hours when zeolite seed was added, but no other differences were observed when excessive sodium hydroxide was added. Consequently, the overall reaction time required could be reduced by adding zeolite seed and changing thermal treatment temperature. However, addition of NaOH does not show significant effect on the reduction of zeolite synthesis time.

Effect of Molten Salts on Synthesis and Upconversion Luminescence of Ytterbium and Thulium-Doped Alkaline Yttrium Fluorides

2018 ◽  
Vol 766 ◽  
pp. 34-39 ◽  
Author(s):  
Thanataon Pornpatdetaudom ◽  
Karn Serivalsatit
Keyword(s):  
Visible Light ◽  
Molten Salt ◽  
Ultraviolet Light ◽  
Laser Diode ◽  
Molten Salts ◽  
Upconversion Luminescence ◽  
The Other ◽  
Ultraviolet Region ◽  
Molten Salt Method ◽  
Lower Intensity

Upconversion luminescence materials have recently received attentions because of theirs light conversion ability from infrared into visible and ultraviolet light. In this work, alkaline yttrium fluoride doped by ytterbium and thulium (AYF4: 20%Yb3+, 0.5%Tm3+) were synthesized by molten salt method at 400 °C for 2 hours with different eutectic molten salts, i.e. NaNO3-KNO3, NaNO3-LiNO3, KNO3-LiNO3, and NaNO3-KNO3-LiNO3. Pure hexagonal NaYF4 microrods were successfully synthesized using eutectic NaNO3-KNO3 molten salt. Under 980 nm laser diode excitation, upconversion luminescence in both visible and ultraviolet region was clearly observed. On the other hand, for the use of other eutectic molten salts containing LiNO3, the mixed phases of tetragonal LiYF4 and orthorhombic Y6O5F8 were obtained. These powders emitted only visible light with 10 times lower intensity than the hexagonal NaYF4 microrods synthesized using NaNO3-KNO3.

Sintering of Ba1-XSrXTiO3 Powders Prepared Using KOH-KNO3 Molten Salt Method

2009 ◽  
Vol 421-422 ◽  
pp. 235-238 ◽  
Author(s):  
Tomohiko Kishiki ◽  
Masashi Higuchi ◽  
Takashi Asaka ◽  
Yasuo Azuma ◽  
Keiichi Katayama
Keyword(s):  
Electrical Properties ◽  
Molten Salt ◽  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Molten Salts ◽  
Sintering Behavior ◽  
Molten Salt Method ◽  
Barium Strontium ◽  
Perovskite Type ◽  
Perovskite Type Structure

Barium strontium titanate (BST), which has a typical perovskite-type structure, shows excellent electrical properties. BST powders were synthesized by heating mixtures of commercial reagents with an excess of TiO2 in molten salts of KOH and KNO3, and the sintering behavior of the resulting powders was evaluated. The sample with the highest density of 95% was obtained by sintering of the BST powders.

Study on Mullite Whiskers Preparation via Non-Hydrolytic Sol-Gel Process Combined with Molten Salt Method

2016 ◽  
Vol 848 ◽  
pp. 295-300 ◽  
Author(s):  
Kai Lin Fu ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Guo Feng ◽  
Mu Pan
Keyword(s):  
Molten Salt ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Molten Salt Method ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Anhydrous Aluminum Chloride ◽  
Oxygen Donor ◽  
Sol Gel Process ◽  
Mullite Whiskers

Mullite whiskers were prepared via non-hydrolytic sol-gel process combined with molybdate molten salt using tetraethoxysilane and anhydrous aluminum chloride as precussor, anhydrous ether as oxygen donor, molybdate as molten salt. The effects of heat treatment temperature, molten salt amount, holding time on synthesis and morphology of mullite whiskers were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The results show that the mullite whiskers appeared at the lowest temperature of 800°C, and optimized mullite whiskers could be prepared at 900°C for 8 h with the mass ratio of xerogel and molybdate as 1:2, the diameter of the whiskers was in the range of 0.15-0.22 μm with the aspect ratio of more than 40.

scholarly journals Magnetic and morphological properties of Ca substituted M-type hexaferrite powders synthesized by the molten salt method

AIP Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 055310
Author(s):  
Minyeol Kim ◽  
Kwiyoung Lee ◽  
Cheoljun Bae ◽  
Jongryoul Kim
Keyword(s):  
Molten Salt ◽  
Morphological Properties ◽  
Molten Salt Method

scholarly journals Concentrated Solar Power Plants with Molten Salt Storage: Economic Aspects and Perspectives in the European Union

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Andrzej Bielecki ◽  
Sebastian Ernst ◽  
Wioletta Skrodzka ◽  
Igor Wojnicki
Keyword(s):  
Molten Salt ◽  
Molten Salts ◽  
Power Plants ◽  
Solar Power ◽  
Economic Aspects ◽  
The European Union ◽  
Concentrated Solar Power ◽  
Eu Legislation ◽  
Solar Power Plants ◽  
Concentrated Solar Power Plants

Concentrated solar power plants belong to the category of clean sources of renewable energy. The paper discusses the possibilities for the use of molten salts as storage in modern CSP plants. Besides increasing efficiency, it may also shift their area of application: thanks to increased controllability, they may now be used not only to cover baseload but also as more agile, dispatchable generators. Both technological and economic aspects are presented, with focus on the European energy sector and EU legislation. General characteristics for CSP plants, especially with molten salt storage, are discussed. Perspectives for their development, first of all in economic aspects, are considered.

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