A study on the low-temperature wet synthesis of hydrofluoric acid from synthetic calcium fluoride and waste sulfuric acid

Bentonites are aluminosilicate minerals which, due to their porosity, layered structure and composition have a wide application. Structural and textural characteristics of bentonite may be improved by different modification procedures. The aim of this study was to investigate compositional, structural and textural characteristics of domestic bentonite in place Gerzovo, before and after the activation with sulfuric acid. These characteristics were investigated by analytical methods, X-ray diffraction (XRD) and the method of low-temperature nitrogen adsorption (BET). Characteristics of acid-activated bentonite were compared with the characteristics of commercial active clay. The obtained results showed that the activation of bentonite with sulfuric acid leads to a significant improvement in structural and textural characteristics. Using these results it can be assumed that this bentonite will have good adsorption characteristics and can serve as an alternative in comparison with imported commercial aluminosilicate-based adsorbents.

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Coupled heating/acidification pretreatment of chemical sludge for dewatering by using waste sulfuric acid at low temperature

Chemosphere ◽

10.1016/j.chemosphere.2018.04.120 ◽

2018 ◽

Vol 205 ◽

pp. 260-266 ◽

Cited By ~ 10

Author(s):

Bo Bian ◽

Limin Zhang ◽

Qin Zhang ◽

Shaopeng Zhang ◽

Zhen Yang ◽

...

Keyword(s):

Sulfuric Acid ◽

Low Temperature ◽

Chemical Sludge

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Electropolishing valve metals with a sulfuric acid-methanol electrolyte at low temperature

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2018.04.082 ◽

2018 ◽

Vol 347 ◽

pp. 150-156 ◽

Cited By ~ 7

Author(s):

Pete Barnes ◽

Andreas Savva ◽

Kiev Dixon ◽

Hailey Bull ◽

Laura Rill ◽

...

Keyword(s):

Sulfuric Acid ◽

Low Temperature ◽

Valve Metals

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Condensation Characteristic of Sulfuric Acid Vapor on Low-Temperature Surface of Tube Heat Exchanger

10.1007/978-981-16-1657-0_70 ◽

2021 ◽

pp. 911-928

Author(s):

Ke Sun ◽

Yu Yan ◽

Fangfang Hu ◽

Lei Deng ◽

Defu Che

Keyword(s):

Sulfuric Acid ◽

Heat Exchanger ◽

Low Temperature ◽

Acid Vapor ◽

Tube Heat Exchanger ◽

Temperature Surface

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The calcium fluoride effect on properties of cryolite melts feasible for low-temperature production of aluminum and its alloys

10.1063/1.4989946 ◽

2017 ◽

Author(s):

O. Tkacheva ◽

A. Dedyukhin ◽

A. Redkin ◽

Yu. Zaikov

Keyword(s):

Low Temperature ◽

Calcium Fluoride

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Modification of Solvolytic Sol-Gel Synthesis for Low Temperature TiO2 DSSC Photoelectrode

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.979.39 ◽

2014 ◽

Vol 979 ◽

pp. 39-42

Author(s):

Saran Kalasina ◽

Taweechai Amornsakchai ◽

Udom Asawapirom

Keyword(s):

Low Temperature ◽

Tin Oxide ◽

Hydrofluoric Acid ◽

Sol Gel ◽

Cell Efficiency ◽

Dye Sensitized ◽

Degussa P25 ◽

Main Component ◽

Sol Gel Synthesis ◽

Dry Film

Solvolytic sol-gel synthesis was applied for the low temperature production of photoelectrode for dye-sensitized solar cell (DSSC). In this study, commercial TiO2 standard (Degussa P25) was used as the main component in the preparation of photoelectrode film. Addition of TiO2 gel prepared from a solvolytic sol-gel method reduced cracking in the dry film while still maintains porosity. Further modification by simply adding hydrofluoric acid (HF) and ammonia (NH3) increase porosity and improve interconnection between fluorine doped tin oxide (FTO) layer on the substrate and the coated TiO2 layer even under low temperature baking condition (<150°C). The modified TiO2 electrode showed significantly better electrical and electrochemical properties. Furthermore, the DSSC cell with modified TiO2 film also showed higher cell efficiency when compared with the controlled cell that used only Degussa P25.

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