Extraction of lithium and aluminium from bauxite mine tailings by mixed acid treatment without roasting

2021 ◽  
Vol 404 ◽  
pp. 124044
Author(s):  
Yusong Zhang ◽  
Jie Zhang ◽  
Lin Wu ◽  
Lin Tan ◽  
Fei Xie ◽  
...  
2015 ◽  
Vol 15 (3) ◽  
pp. 2552-2555 ◽  
Author(s):  
J. M. Zhao ◽  
W. U. Park ◽  
K. H. Hwang ◽  
J. K. Lee ◽  
S. Y. Yoon

2011 ◽  
Vol 306-307 ◽  
pp. 1444-1449
Author(s):  
Rui Li ◽  
Yuan Zhong Hu ◽  
Hui Wang

This paper investigates mechanism of tribological behavior of carbon nanotubes by using universal tribometer-II and molecular dynamics simulations. The experiment results indicate that multi-walled carbon nanotubes film with mixed acid treatment has better surface quality and less impurities but higher friction than pristine carbon nanotubes film. The reason is that mixed acid treatment introduces carboxyl group and more defects which increases dangling bonds of carbon nanotubes. Breaking of dangling bonds increases friction force when sliding and shearing occurs. Molecular dynamics simulation of shearing between silicon surfaces and single-walled carbon nanotube bundles without defect shows low lateral forces because only van der walls force exists between silicon surfaces and carbon nanotubes owing to no dangling bonds. The result is consistent to the conclusion inferred from experiment. Therefore excellent performance is expected when carbon nanotubes treated with little defects are used as lubricant or addictives.


2013 ◽  
Vol 295-298 ◽  
pp. 1768-1775
Author(s):  
Hai Wei Ren ◽  
Jin Ping Li ◽  
Fei Zhang

Waste distiller's grains (WDG),a co-product of brewing industry, was an abundant source of biomass that could be hydrolyzed to yield fermentation sugar for the production of fuel ethanol. In this study, hydrolysis of WDG using mixed acid as catalysts was examined with the indices of the concentration of reducing sugar and furfural. The structural characteristics of WDG before and after acid treatment were also discussed by means of SEM, FTIR and XRD. The results indicate that there are 59.32gL-1 reducing sugar under the conditions of 100°C, solid-liquid ratio of 1:12 gmL-1, acid concentrations of 2.0% and time of 120 min, with the conversions rate of 77.38% and 62.50% for hemicelluloses and cellulose, respectively. SEM photographs show that the structural modifications after acid treatment are pronounced in comparison to that of WDG, which present a rigid and compact morphology. A lot of large irregular pores with different sizes and shapes are formed and the structures are also severely distorted resulting in the increasing surface exposure and porosity. Instrumental analyses with FTIR and XRD indicate that the strength of characteristic peaks for corresponding typical functional groups of each component are changed compared with the feedstock, and there is an increase of the crystallinity index when WDG is subjected to the MACH treatment.


2019 ◽  
Vol 85 (874) ◽  
pp. 19-00029-19-00029
Author(s):  
Kouichi OKUMO ◽  
Yui TAKAHASHI ◽  
Taesung KIM ◽  
Hidefumi NIKAWA ◽  
Atsushi HOSOI ◽  
...  

Carbon ◽  
2008 ◽  
Vol 46 (4) ◽  
pp. 611-617 ◽  
Author(s):  
Dong Young Kim ◽  
Cheol-Min Yang ◽  
Hiroshi Noguchi ◽  
Masahiro Yamamoto ◽  
Tomonori Ohba ◽  
...  

2011 ◽  
Vol 493-494 ◽  
pp. 787-790
Author(s):  
Toshiyuki Kawai ◽  
Mitsuru Takemoto ◽  
Shunsuke Fujibayashi ◽  
Masashi Neo ◽  
Deepak K. Pattanayak ◽  
...  

We previously found that a positively charged Ti metal has a higher apatite forming ability in vitro than a non-charged Ti metal. For in vivo analysis using a rabbit model, two types of Ti metal were examined: porous Ti metals heat-treated subsequent to a mixed acid treatment (MHs) and porous Ti metals not heat-treated subsequent to the same mixed acid treatment (MOs). Although MHs and MOs had the same macro- and micro-structure, they had different surface charges. MHs, considered positively charged, had significantly higher bone ingrowth than MOs, considered charged zero. Similarly, MHs had significantly higher percentages of bone–implant contact than MOs at 3- and 6-week. A simple heat treatment made acid-treated porous titanium implants more osteoconductive. These results suggest that a positive charge obtained by a heat treatment enhances bioactivity of acid-treated titanium implants.


Author(s):  
George F. Leeper

Polysaccharide elementary fibrils are usually fasciated into microfibrils of from one hundred to a few hundred Angstroms wide. Cellulose microfibrils when subjected to acid treatment dissociate into component elementary fibrils. For pectic acid it was observed that variations in pH could cause a change in the fasciation of the elementary fibrils.Solutions of purified pectic acid and sodium phosphotungtate were adjusted to various pH levels with NaOH or HCl and diluted to give a final concentration of 0.5 and 1% for the polysaccharide and negative stains respectively. Micrographs were made of the samples after drying on a carbon film covered grid. The average number of elementary fibrils was determined by counting the number of elementary fibrils in each fascicle intersected by lines drawn across the micrograph.


2020 ◽  
Author(s):  
M Kreuter ◽  
F Bonella ◽  
N Blank ◽  
E Siegert ◽  
J Henes ◽  
...  

2006 ◽  
Vol 37 (06) ◽  
Author(s):  
M Rauchenzauner ◽  
E Haberlandt ◽  
S Scholl-Bürgi ◽  
D Karall ◽  
E Schönherr ◽  
...  

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