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Wyszukujesz frazę "xanthate" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Adsorption mechanism of copper xanthate on pyrite surfaces
Autorzy:
Deng, Zhengbin
Cheng, Wanli
Tang, Yun
Tong, Xiong
Liu, Zhihong
Powiązania:
https://bibliotekanauki.pl/articles/1447276.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pyrite
cupric xanthate
cuprous xanthate
adsorption
surface
Opis:
The ratio of the hydrophobic to hydrophilic species and their distribution on mineral surfaces significantly influences the floatability of sulfide minerals. Through the flotation test, the influence of different reagents on pyrite flotation was examined. The interaction mechanisms between copper xanthate and pyrite were evaluated using advanced analysis technologies, including contact angle measurements, zeta potential analysis, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results show that the butyl xanthate in solution reacts with copper sulfate to form cupric xanthate, increasing the consumption of the collector butyl xanthate and resulting in lower floatability of pyrite. Cupric xanthate can be adsorbed on the pyrite surface through bonding with the sulfur sites. The adsorbed cupric xanthate on the pyrite surface undergoes redox reaction. The cupric xanthate is reduced to cuprous xanthate, and the sulfur on the surface will be oxidized. The adsorption products on the pyrite surface contain both cuprous xanthate and cupric xanthate. As the pH of a solution increases, the absolute value of the zeta potential of pyrite surface increased and the surface contact angle increased. Iron xanthate is also formed on the pyrite surface through a chemical reaction between the xanthate ions and pyrite, oxidation of xanthate ions to dixanthogen also takes place. Cuprous xanthate is the main hydrophobic substance on the pyrite surface, which can change the surface electrical properties and wettability of pyrite, and improve hydrophobicity of pyrite.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 3; 46-60
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of anionic, cationic and amphoteric collectors used in pyrite flotation
Autorzy:
Bulut, Gülay
Sirkeci, A. A.
Arı, Beril
Powiązania:
https://bibliotekanauki.pl/articles/1446764.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
pyrite
amine
collectors
xanthate
Opis:
In this study, flotation tests were conducted with purified pyrite and ore samples. The collectors employed were anionic and cationic type such as potassium ethlyl-amyl xanthate, Tomamine M73 and Resanol Bal. According to the flotation tests, it was found that pyrite floated at low pH and depressed at high pH values with xanthates. On the other hand, in the case of cationic collectors which are Tomamine M73 (alkyl ether amine, an amphoteric surfactant) and Resanol Bal (N-3-tridecyloxy propyl 1-3 diamine, branched acetate) pyrite floated at high pH values. It was shown that amine type collectors could be efficient to selectively float pyrite from chalcopyrite at alkali pH ranges in the case of ore samples.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 5; 15-22
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of alkyl chain length in the inhibitory effect n-alkyl xanthates on mushroom tyrosinase activities
Autorzy:
Saboury, Ali
Alijanianzadeh, Mahdi
Mansoori-Torshizi, Hasan
Powiązania:
https://bibliotekanauki.pl/articles/1041136.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mushroom tyrosinase
mixed inhibition
uncompetitive inhibition
alkyl xanthate
competitive inhibition
inhibition constant
Opis:
Sodium salts of four n-alkyl xanthate compounds, C2H5OCS2Na (I), C3H7OCS2Na (II), C4H9OCS2Na (III), and C6H13OCS2Na (IV) were synthesized and examined for inhibition of both cresolase and catecholase activities of mushroom tyrosinase (MT) in 10 mM sodium phosphate buffer, pH 6.8, at 293 K using UV spectrophotemetry. 4-[(4-methylbenzo)azo]-1,2-benzendiol (MeBACat) and 4-[(4-methylphenyl)azo]-phenol (MePAPh) were used as synthetic substrates for the enzyme for catecholase and cresolase reactions, respectively. Lineweaver-Burk plots showed different patterns of mixed, competitive or uncompetitive inhibition for the four xanthates. For the cresolase activity, I and II showed uncompetitive inhibition but III and IV showed competitive inhibition pattern. For the catecholase activity, I and II showed mixed inhibition but III and IV showed competitive inhibition. The synthesized compounds can be classified as potent inhibitors of MT due to their Ki values of 13.8, 11, 8 and 5 µM for the cresolase activity, and 1.4, 5, 13 and 25 µM for the catecholase activity for I, II, III and IV, respectively. For the catecholase activity both substrate and inhibitor can be bound to the enzyme with negative cooperativity between the binding sites (α > 1) and this negative cooperativity increases with increasing length of the aliphatic tail of these compounds. The length of the hydrophobic tail of the xanthates has a stronger effect on the Ki values for catecholase inhibition than for cresolase inhibition. Increasing the length of the hydrophobic tail leads to a decrease of the Ki values for cresolase inhibition and an increase of the Ki values for catecholase inhibition.
Źródło:
Acta Biochimica Polonica; 2007, 54, 1; 183-191
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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