FLOTATION SEPARATION OF DIASPORE AGAINST ALUMINOSILICATE MINERALS
USING N-(4-(HYDROXYAMINO)-4-OXOBUTYL)ALKYLAMIDE SURFACTANTS AS
COLLECTORS
Lanqing Deng, Hong Zhong*, Gang Zhao, Shuai Wang, Guangyi Liu
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
ABSTRACT
Three novel surfactants containing double reactive centers(-CONHOH and –CONH-), double
hydrophobic groups were designed and synthesized as collector for separation of diaspore and
aluminosilicate minerals, such as N-(4-(hydroxyamino)-4-oxobutyl)octanamide (HA-8), N-(4(hydroxyamino)-4-oxobutyl)decanamide (HA-10) and N-(4-(hydroxyamino)- 4-oxobutyl)-dodecanamide
(HA-12). The adsorption mechanism of N-(4-(hydroxyamino) -4-oxobutyl)alkylamides (HA) onto diaspore
was also investigated by FTIR spectra, zeta potential measurement and DFT. The flotation results
demonstrated that three collectors all exhibited superior collecting power to diaspore and selectivity against
kaolinite and illite, and could effectively realize flotation recovery of diaspore from bauxite ores contained
aluminosilicate minerals under neutral conditions. Moreover, HA-12 was a superior collector than other
two collectors for bauxite separation. The results of FTIR spectra and zeta potential illustrated that at
around pH 6.0, HA might chemisorb on diaspore surfaces through Al-O coordination bonds formed by
binding its –C(=O)NHOH or –C(=O)NH– chelate groups with aluminum atoms on diaspore surfaces. HA’s
unique properties, such as characteristic bond patterns onto diaspore surfaces, double hydrophobic groups,
and intermolecular hydrogen bonds between neighboring HA molecules coated on diaspore surfaces,
rendered it to be a superior flotation collector for diaspore.
100
100
a
HA-10
HA-8
HA-12
80
Recovery/%
80
Recovery/%
kaolinite
b
60
40
60
40
diaspore
20
HA-8
HA-12
HA-10
0
2
4
6
8
10
12
20
0
2
4
6
8
10
12
pH
pH
Figure 1 –Recovery of diaspore (a) and kaolinite (b) as a function of pH by using HA-8, HA-10, or HA-12
as collectors (100 mg/L)
KEYWORDS
Flotation, Diaspore, Aluminosilicate mineral, Hydroxamic acid
*
Corresponding author: Tel & Fax number: +86-731-88830654, E-mail: zhongh@csu.edu.cn.