scholarly journals Activation Mechanism of Lead(II) to Ilmenite Flotation Using Salicylhydroxamic Acid as Collector

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 567
Author(s):  
Hang Liu ◽  
Wenqing Zhao ◽  
Jihua Zhai ◽  
Xiaolong Lu ◽  
Pan Chen ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Adsorption Mechanism ◽  
Lead Ions ◽  
Activation Mechanism ◽  
Salicylhydroxamic Acid ◽  
Benzohydroxamic Acid ◽  
Adsorption Analysis ◽  
Potential Shifts ◽  
Lead Species

In this study, salicylhydroxamic acid (SHA), which exhibits superior flotation performance to conventional collector benzohydroxamic acid (BHA), was first introduced in ilmenite flotation. The addition of lead(II) can significantly increase the recovery of ilmenite using SHA as collector. Thus, the adsorption mechanism of SHA on lead(II)-activated ilmenite surface was systematically studied using micro-flotation tests, adsorption analysis, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Micro-flotation results revealed that SHA had stronger collecting ability than BHA, and ilmenite floatability could be activated by lead ions with either SHA or BHA as collector. Ilmenite showed good floatability at pH 6–8 (over 90% recovery) in the presence of Pb2+ and SHA. In such conditions, the main lead species of Pb(OH)+ and Pb2+ acted as active sites and caused positive surface potential shifts, thereby increasing the adsorbed amounts of negatively charged SHA on the surface of the mineral. FTIR and XPS analyses suggested that the lead species was chemically adsorbed on the surface of ilmenite to form active sites chelated by SHA. Moreover, the free lead ions in solution might form the Pb–SHA complexes to adsorb on the mineral surface, thereby increasing the floatability of ilmenite.

scholarly journals Activation Mechanism of Lead Ions in Perovskite Flotation with Octyl Hydroxamic Acid Collector

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 341 ◽  
Author(s):  
Yu Zheng ◽  
Yating Cui ◽  
Weiqing Wang
Keyword(s):  
Zeta Potential ◽  
Photoelectron Spectroscopy ◽  
Hydroxamic Acid ◽  
Relative Content ◽  
Lead Ions ◽  
Activation Mechanism ◽  
X Ray ◽  
Ft Ir ◽  
Acidic Conditions ◽  
Ir Analysis

The activation mechanism of lead ions (Pb2+) in perovskite flotation with an octyl hydroxamic acid collector was systematically investigated using microflotation experiments, zeta-potential measurements, adsorption tests, Fourier transform infrared (FT-IR) analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The results of microflotation experiments and adsorption tests indicate that the presence of Pb2+ can promote the adsorption of octyl hydroxamic acid (OHA) on the perovskite surface and enhance the flotability of perovskite under weakly acidic conditions. The maximum recovery of 79.62% was obtained at pH 6.5 in the presence of Pb2+, and the maximum recovery of 57.93% was obtained at pH 5.7 without Pb2+. At pHs below 7, lead species are mainly present as Pb2+ and PbOH+ in the solution; besides this, the relative content of titanium increases on the perovskite surface. The adsorption of Pb2+ and PbOH+ on the perovskite surface makes the zeta-potential of perovskite shift positively, and increases the number of activated sites on the perovskite surface. FT-IR and XPS analyses confirm that OHA chemisorbs on the surface of Pb2+-activated perovskite and forms hydrophobic Pb-OHA complexes, which improve the flotability of perovskite.

scholarly journals The Performance and Adsorption Mechanism of a Novel Collector, Dodecyl Dimethyl Betaine (BS-12), for the Flotation Separation of Ilmenite and Titanaugite

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 116 ◽  
Author(s):  
Pan Chen ◽  
Xujian Chai ◽  
Mengjie Tian ◽  
Wei Chen ◽  
Si Wan ◽  
...  
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Adsorption Mechanism ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Xps Analysis ◽  
Spectroscopy Analysis ◽  
Ft Ir ◽  
Ph Range

In this paper, a novel collector, dodecyl dimethyl betaine (BS-12), was used in the selective separation of ilmenite from titanaugite. The flotation performance and associated adsorption mechanism were studied by micro-flotation experiments, particle size analysis, Fourier-transform infrared (FT-IR) spectroscopy analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The micro-flotation results indicated that BS-12 exhibited a stronger collecting ability towards ilmenite than titanaugite within an acidic pH range, and that the recovery of ilmenite was about 50% higher than that of titanaugite under the optimum flotation conditions. Particle size analysis demonstrated that BS-12 could selectively agglomerate ilmenite to a certain extent and then contribute to the flotation difference between ilmenite and titanaugite. FT-IR results showed some characteristic bands of BS-12 on treated ilmenite, and on titanaugite with BS-12. The XPS analysis further confirmed that BS-12 chemisorbed onto ilmenite and titanaugite in a similar way, but the limited active sites on titanaugite in comparison with ilmenite accounted for their differences in flotation.

scholarly journals A Highly Selective Reagent Scheme for Scheelite Flotation: Polyaspartic Acid and Pb–BHA Complexes

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 561
Author(s):  
Zhao Wei ◽  
Junhao Fu ◽  
Haisheng Han ◽  
Wei Sun ◽  
Tong Yue ◽  
...  
Keyword(s):  
Crystal Chemistry ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
High Selectivity ◽  
Selective Adsorption ◽  
Mineral Surfaces ◽  
Polyaspartic Acid ◽  
Benzohydroxamic Acid ◽  
Successful Separation ◽  
Selective Reagent

Previous studies have proved that the lead complexes of benzohydroxamic acid (Pb–BHA) are effective collectors of scheelite flotations; however, the separation of scheelite from calcite needs depressants with high selectivity. In this study, we reported a novel depressant for calcite minerals, and Pb–BHA served as the collector of scheelite. The flotation behavior of polyaspartic acid (PASP) in a scheelite and calcite flotation that uses Pb–BHA was determined via flotation experiments. Furthermore, the selective adsorption of PASP on the mineral surfaces and the effect of PASP on the adsorption of Pb–BHA on the mineral surfaces were investigated through zeta potential measurements, X-ray photoelectron spectroscopy (XPS), crystal chemistry calculations, and Fourier transform infrared spectroscopy (FTIR) measurements. Thus, PASP demonstrated high selectivity in both scheelite and calcite and contributed to the successful separation of scheelite from calcite. PASP exhibited a higher adsorption capacity and stronger chemisorption with the active sites of calcium atoms on the calcite surface. The crystal chemistry calculations indicated that the distance of the PASP functional groups matched with the calcium distance of a calcite mineral surface, which can be attributed to the selectivity of PASP. Furthermore, the adsorption of PASP impeded the adsorption of Pb–BHA on the calcite surfaces, whereas the opposite was the case for scheelite. The mutually reinforcing selectivity of PASP and Pb–BHA considerably contributes to the efficient flotation separation of scheelite from calcite.

Adsorption Mechanism Study of Magnetic EDTA-Chitosan on Cu (II) Ions of Solution

2014 ◽  
Vol 937 ◽  
pp. 218-223
Author(s):  
Run Hua Qin ◽  
Feng Sheng Li ◽  
Wei Jiang ◽  
Ling Yun Hao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Adsorption Mechanism ◽  
Influence Factor ◽  
Adsorption Property ◽  
Chelating Agent ◽  
Magnetic Adsorbent ◽  
Mechanism Study ◽  
X Ray ◽  
Adsorption Mechanisms

A novel magnetic adsorbent, magnetic EDTA/chitosan nanobeads was synthesized. The adsorption mechanisms of magnetic EDTA/chitosan nanobeads for removal of Cu (II) ions from aqueous solution were investigated in this paper. The interaction mechanisms of Cu2+ adsorption onto magnetic EDTA/chitosan nanobeads and active sites were interpreted by fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. Uniting the analysis results of FTIR and XPS, the functional groups of participating in chelating were confirmed, and the results indicated that Cu2+ adsorption was mainly through interactions with electron donating atom N and O. This adsorption property was similar to N·O-type chelating agent and the adsorption mechanism was put forward. This work was very significant to control adsorption influence factor and improve adsorption capacity of magnetic EDTA-chitosan nanobeads, and then succeed to apply to magnetic adsorption fields.

scholarly journals Selective Flotation of Cassiterite from Calcite with Salicylhydroxamic Acid Collector and Carboxymethyl Cellulose Depressant

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 316 ◽  
Author(s):  
Mengjie Tian ◽  
Zhiyong Gao ◽  
Bin Ji ◽  
Ruiying Fan ◽  
Runqing Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carboxymethyl Cellulose ◽  
Lead Nitrate ◽  
Gangue Mineral ◽  
Similar Response ◽  
Spectroscopy Analysis ◽  
Salicylhydroxamic Acid ◽  
Benzohydroxamic Acid ◽  
Tin Deposit ◽  
Difficult Issue

Cassiterite is the most common and important tin-bearing mineral, and calcite, a primary gangue mineral is generally found in tin deposit. The flotation separation of cassiterite from calcite remains a challenge due to their similar response to traditional reagents. In cassiterite flotation, sodium oleate (NaOL) and sodium silicate (SS) have been widely used as a collector and a depressant, respectively. However, the low selectivity of NaOL and the large amount of SS required (which leads to serious problems in wastewater treatment) remain a difficult issue. In this study, a novel reagent scheme using lead nitrate as the activator, salicylhydroxamic acid (SHA) as the collector and carboxymethyl cellulose as the depressant was employed to improve the separation selectivity of cassiterite from calcite. Results of the flotation experiment using this new reagent scheme showed that compared with the previously reported scheme using benzohydroxamic acid (BHA) as the collector, the separation of cassiterite from calcite exhibited a higher selectivity and selectivity index (SI). The mechanism of the selective separation was investigated by zeta potential measurements, Fourier transform infrared and X-ray photoelectron spectroscopy analysis.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

scholarly journals Multiplicity of Active-Site in Heterogeneous Ziegler-Natta Catalyst and Its Correlation with Polymer Microstructure

1970 ◽  
Vol 46 (4) ◽  
pp. 487-494
Author(s):  
ATM Kamrul Hasan
Keyword(s):  
Molecular Weight ◽  
Computer Simulation ◽  
Active Site ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Chain Structure ◽  
Surface Complexes ◽  
Polymer Microstructure ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst

Multiplicity of active-site in heterogeneous Ziegler-Natta catalysts and its correlation with polymer microstructure was studied through the surface structure analysis of catalyst by computer simulation of X-ray Photoelectron Spectroscopy (XPS) data and microstructure investigation of polypropylene chains based on the deconvolution of the molecular weight distribution curves by multiple Flory most probable distributions using Gel Permeation Chromatography (GPC) method. The number and relative intensities of these peaks were found correlated to the distribution of multiple active sites. In this investigation, four individual categories of active sites were identified, each of which yields polypropylene with unique properties of molecular weight and chain structure different from other active sites. The reason of the multiplicity of active sites was determined by the presence of different locations of surface titanium species coordinated with other surface atoms or molecules. These different surface complexes of active species determine the multiple active site nature of catalyst which replicates the microtacticity, molecular weight and chain microstructure distribution of polymer. Keywords: Ziegler-Natta catalyst; Multiple active sites; Flory components; Computer simulation; Deconvolution; MWD. DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9596 BJSIR 2011; 46(4): 487-494

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