Structure Relationship Between Polar and NonPolar Group in Collector Molecule
It is frequently seen that, for the collectors with various polar groups, there is a great difference in the size of nonpolar group.
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Structure Relationship Between Polar and NonPolar Group in Collector Molecule
5.1
Correlation Between Size of NonPolar Group and Variety of Polar Group
It is frequently seen that, for the collectors with various polar groups, there is a great difference in the size of nonpolar group. For different polar groups, the problem that what size of nonpolar group makes reagent own enough collecting capability is still not solved. For example, C.I. Mitrofanov proposed the minimum size of nonpolar group for common reagents, and the data are listed in Table 5.1. It can be seen that the results about the size of nonpolar group are not in agreement with the actual data. Especially for the collectors for oxide minerals, the discrepancy is more obvious. For the purpose of establishing the relationship between molecular weight of nonpolar group and variety of polar group, the related theory calculations of polar and nonpolar groups such as CMC, hydrophile–lipophile balance (HLB), and electronegativity will be carried on in the next Chapter. These calculations are not only based on the surface energy of groups but also on the hydrophilicity of mineral. The most basic condition of mineral being enough hydrophobicity after the adsorption of reagent, in fact, lies in that the surface energy of nonpolar group is larger than that of polar group. The following Tables 5.2 and 5.3 display the surface energies of various groups and metal ions at different conditions [1]. These data are only used to show the variation trend of the surface energy of various groups but can not be used to evaluate quantificationally flotation reagent.
© Metallurgical Industry Press, Beijing and Springer Science+Business Media Singapore 2016 D. Wang, Flotation Reagents: Applied Surface Chemistry on Minerals Flotation and Energy Resources Beneficiation, DOI 10.1007/978-981-10-2030-8_5
127
O
O
–SH
O
S
S
P
C
SMe
S
SMe
S
Category of polar group
4
2
1 2
1
1
2 2
Aromatic ring number
C atoms number in alkyl
–NH2
ONa
O
C
SO3Na
C
N SMe
S
Category of polar group
Table 5.1 Ideal size of nonpolar group for common reagents from C.I. Mitrofanov
8
2 3
2
C atoms number in alkyl
–
1 –
2
Aromatic ring number
128 5 Structure Relationship Between Polar and NonPolar Group …
W air/water
W oil/water
–COOH 4330 6820 –OH 24.6 3347.2 104.1 –NH2 2133.8 –CONH2 –CO– Where, W refers to the surface energy; eW refers to energy of –CH2–
Group
1255.2
–SO42− 7531.2
7531.2
W oil/water
7322
2092
eW
Alkyl oil nitrobenzene Air (weak solution) Air (strong solution)
–CH2– in water phase
3389 2448 2510 2920
Ф
3974.8 –N(CH3)+3 the surface energy of the adsorption of monovalent ion in electric double layer; Ф refers to the surface
1255.2
W air/water
–SO4
Group
Table 5.2 Adsorption energies of various groups on different interfaces from Davies (J/mol)
5.1 Correlation Between Size of NonPolar Group and Variety of Polar Group 129
5 Structure Relationship Between Polar and NonPolar Group …
130 Table 5.3 Adsorption energies of metal ions on
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