scholarly journals Relationship between Surface Characteristics and Floatability in Representative Sulfide Minerals: Role of Surface Oxidation

2017 ◽  
Vol 58 (7) ◽  
pp. 1069-1075 ◽  
Author(s):  
Gilsang Hong ◽  
Junhyun Choi ◽  
Yosep Han ◽  
Kwang-Suk Yoo ◽  
Kwanho Kim ◽  
...  
Keyword(s):  
Surface Oxidation ◽  
Surface Characteristics ◽  
Sulfide Minerals

Bioflotation of sulfide minerals with Acidithiobacillus ferrooxidans in relation to copper activation and surface oxidation

2012 ◽  
Vol 58 (9) ◽  
pp. 1073-1083 ◽  
Author(s):  
E.T. Pecina-Treviño ◽  
G.T. Ramos-Escobedo ◽  
P.M. Gallegos-Acevedo ◽  
F.J. López-Saucedo ◽  
E. Orrantia-Borunda
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Elemental Sulfur ◽  
Surface Oxidation ◽  
Surface Characteristics ◽  
Growth Media ◽  
Bacterial Cells ◽  
Sulfur Concentration ◽  
Key Factors ◽  
Culture Cells

Surface oxidation of sulfides and copper (Cu) activation are 2 of the main processes that determine the efficiency of flotation. The present study was developed with the intention to ascertain the role of the phenomena in the biomodification of sulfides by Acidithiobacillus ferrooxidans culture (cells and growth media) and their impact in bioflotation. Surface characteristics of chalcopyrite, sphalerite, and pyrrhotite, alone and in mixtures, after interaction with A. ferrooxidans were evaluated. Chalcopyrite floatability was increased substantially by biomodification, while bacteria depressed pyrrhotite floatability, favoring separation. The results showed that elemental sulfur concentration increased because of the oxidation generated by bacterial cells, the effect is intensified by the Fe(III) left in the culture and by galvanic contact. Acidithiobacillus ferrooxidans culture affects the Cu activation of sphalerite. The implications of elemental sulfur concentration and Cu activation of sphalerite are key factors that must be considered for the future development of sulfide bioflotation processes, since the depressive effect of cells could be counteracted by elemental sulfur generation.

scholarly journals Role of surface oxidation for thickness-driven insulator-to-metal transition in epitaxial MoO2 films

2018 ◽  
Vol 459 ◽  
pp. 92-97 ◽  
Author(s):  
Eunyoung Ahn ◽  
Taewon Min ◽  
Jaekwang Lee ◽  
Inwon Lee ◽  
Younghak Kim ◽  
...  
Keyword(s):  
Surface Oxidation

scholarly journals Effects of Titanium Surfaces on the Developmental Profile of Monocytes/Macrophages

2014 ◽  
Vol 25 (2) ◽  
pp. 96-103 ◽  
Author(s):  
Camilla Christian Gomes Moura ◽  
Darceny Zanetta-Barbosa ◽  
Paula Dechichi ◽  
Valessa Florindo Carvalho ◽  
Priscilla Barbosa Ferreira Soares
Keyword(s):  
Cell Viability ◽  
Colorimetric Assay ◽  
Initial Period ◽  
Critical Role ◽  
Surface Characteristics ◽  
Th2 Cytokine ◽  
Titanium Surfaces ◽  
Control Surfaces ◽  
Immunoenzymatic Assays

Due to the critical role of monocytes/macrophages (Mϕ) in bone healing, this study evaluated the effects of bio-anodized, acid-etched, and machined titanium surfaces (Ti) on Mϕ behavior. Cells were separated from whole human blood from 10 patients, plated on Ti or polystyrene (control) surfaces, and cultured for 72 h. At 24, 48 and 72 h, cell viability, levels of IL1β, IL10, TNFα, TGFβ1 inflammatory mediators, and nitric oxide (NO) release were analyzed by mitochondrial colorimetric assay (MTT assay) and immunoenzymatic assays, respectively. Real-time PCR was used to verify the expression of TNFα and IL10 at 72 h. The data were subjected to a Kruskal-Wallis analysis. IL1β, TNFα and TGFβ1 release were not significantly different between the Ti surfaces (p>0.05). The presence of NO and IL10 was not detected in the samples. Cell viability did not differ between the samples cultivated on Ti and those cultivated on control surfaces, except at 24 h (p=0.0033). With respect to the mediators evaluated, the surface characteristics did not induce a typical Th1 or Th2 cytokine profile, although the cell morphology and topography were influenced by the Ti surface during the initial period.

The role of surface oxidation on the degradation behavior of biodegradable Mg–RE (Gd, Y, Sc) alloys for resorbable implants

2014 ◽  
Vol 40 ◽  
pp. 407-417 ◽  
Author(s):  
Harpreet S. Brar ◽  
Ida S. Berglund ◽  
Josephine B. Allen ◽  
Michele V. Manuel
Keyword(s):  
Surface Oxidation ◽  
Degradation Behavior ◽  
Resorbable Implants

KT5331AS0 and 45 Steel Milling Comparison of Surface Characteristics

2011 ◽  
Vol 66-68 ◽  
pp. 2062-2068
Author(s):  
Jian Sheng Ding ◽  
Yang Ping Xu
Keyword(s):  
Mass Fraction ◽  
High Speed ◽  
Steel Surface ◽  
Surface Composition ◽  
Surface Hardness ◽  
Surface Oxidation ◽  
Surface Characteristics ◽  
Cutting Parameters ◽  
Machined Surface ◽  
Cooling Conditions

To study the surface composition, hardness, microstructure of the machined surface in KT5331AS0 and 45 steel at different cutting parameters and cooling conditions. The results show that: in the cutting process the mass fraction of W in KT5331AS0 steel surface were reduced to varying degrees, the basic chemical composition of 45 steel surface did not change; When KT5331AS0 steel in the high-speed, higher feed rate, it will be cause surface hardness increasing, however the hardness of 45 steel have no regular variation; 45 steel will have greater depth of the torn surface after milling, tearing a wider range, more obvious surface oxidation.

The role of Cu ion activation and surface oxidation for polymorphic pyrrhotite flotation performance in Strathcona Mill

2019 ◽  
Vol 134 ◽  
pp. 87-96 ◽  
Author(s):  
Chao Qi ◽  
Jing Liu ◽  
Jonathan Malainey ◽  
Lori J. Kormos ◽  
Julie Coffin ◽  
...  
Keyword(s):  
Surface Oxidation ◽  
Ion Activation ◽  
Flotation Performance
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