In this paper, the flotation separation of quartz and feldspar was studied with CaCl 2 as activators and mixed sodium oleate/ dodecylamine (NaOL/DDA) collectors under alkaline condition, and the action mechanism of mixed NaOL/DDA collectors on the quartz and feldspar surfaces were systematically explored. The results of micro-flotation test showed that there were 90.98% quartz and 13.08% feldspar were floated with 0.5 mmol/L CaCl 2 and 2.8 mmol/L mixed NaOL/DDA collectors with molar ratio of 8/1 at pH 10.0. And the artificial mixed minerals flotation manifested these two minerals were able to efficient separation with CaCl 2 and mixed NaOL/DDA collectors at pH 10 ∼ 11. These outcomes indicated that DDA could increase recovery of quartz obviously and reduce about a half dosage of NaOL (from 0.5 mmol/L to 0.25 mmol/L) in flotation under alkaline condition; Meanwhile, mixed NaOL/DDA collectors were able to decreased the flotation separation pH from 12 to 10 on quartz and feldspar. Infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) results revealed that when NaOL collector was added alone, it could adsorb on activated quartz surface but hardly detected on feldspar surface at pH 10. However, they all were found on both quartz and felspar surface when mixed NaOL/DDA collectors were introduced as collectors. Quartz microcrystal balance with dissipation (QCM-D) experiment confirmed that mixed NaOL/DDA collectors showed a higher adsorption mass and more stable adsorption layer on quartz compared with NaOL was introduced as collector alone. In addition, whether CaCl 2 , NaOL or mixed NaOL/DDA, the adsorption mass on quartz sensor were larger than that on feldspar senor, which might cause difference of hydrophobicity on the surface of quartz and feldspar in flotation. The above experiments showed that the mixed NaOL/DDA collectors can significantly improve hydrophobic difference between quartz and feldspar after activating with CaCl 2 and expand the floated pH range of quartz compared with using NaOL as collector alone, which were efficient reagents to separate quartz and feldspar in flotation.
The structure–property relationship and adsorption mechanism of a novel collector for cassiterite, 2-carboxyethylphenylphosphinic acid (CEPPA), were comprehensively investigated and compared with those of styrene phosphonic acid (SPA) by density functional theory (DFT) calculations and flotation tests. The net Mulliken charge and frontier molecular orbital (FMO) theory study results indicated that CEPPA exhibited stronger electron-donating ability and higher chemical reactivity than SPA. The flotation test results demonstrated that CEPPA had stronger collecting ability for cassiterite in a much wider effective pH range than SPA. The adsorption simulation results confirmed that the CEPPA molecule was adsorbed on cassiterite (110) surface by two hydrogen bonds. CEPPA monoanion and dianion were adsorbed on cassiterite (110) surface by a series of O-Sn bonds, and the interactions between the O atoms in CEPPA phosphinic group with the Sn atoms on cassiterite (110) surface were stronger than those between the O atoms in CEPPA carboxyl group with the Sn atoms on cassiterite (110) surface. The formation of the O-Sn bonds was mainly contributed from the 2p orbital of O atoms and 5s and 5p orbitals of Sn atoms. The various adsorption configurations of CEPPA on cassiterite accounted for the better collecting ability of CEPPA for cassiterite than that of SPA. The quantitative analysis results were in good agreement with the qualitative experimental test results in a previous paper.
Wu Zhongxian,Tao Dongping,Tao Youjun,Jiang Man,Zhang Patrick
We analyzed a novel cationic collector using chemical plant byproducts, such as cetyltrimethylammonium bromide (CTAB) and dibutyl phthalate (DBP). Our aim is to establish a highly effective and economical process for the removal of quartz from collophane. A micro-flotation test with a 25 mg·L −1 collector at pH value of 6–10 demonstrates a considerable difference in the floatability of pure quartz and fluorapatite. Flotation tests for a collophane sample subjected to the first reverse flotation for magnesium removal demonstrates that a rough flotation process (using a 0.4 kg·t −1 new collector at pH = 6) results in a collophane concentrate with 29.33wt% P 2 O 5 grade and 12.66wt% SiO 2 at a 79.69wt% P 2 O 5 recovery, providing desirable results. Mechanism studies using Fourier transform infrared spectroscopy, zeta potential, and contact angle measurements show that the adsorption capacity of the new collector for quartz is higher than that for fluorapatite. The synergistic effect of DBP increases the difference in hydrophobicity between quartz and fluorapatite. The maximum defoaming rate of the novel cationic collector reaches 142.8 mL·min −1 . This is considerably higher than that of a conventional cationic collector.
Qinzhi Yuan,Guangjun Mei,Cheng Liu,Qian Cheng,Siyuan Yang
To improve the quality of the iron concentrate, the efficient separation of pyrrhotite from magnetite has always been an important beneficiation objective. In this paper, a novel collector of sulfur-containing ionic liquid (SCIL) was synthesized by using the isobutyl xanthic acid with N -tetrabutyl quaternary ammonium salt, and its molecular structure was characterized by 1 H NMR, 13 C NMR and FTIR analysis. The SCIL was used as a flotation collector for the first time to selectively separate pyrrhotite from magnetite by reverse flotation. Its flotation performance and adsorption mechanism on pyrrhotite or magnetite were investigated by microflotation tests, FTIR spectra, zeta potential measurement, XPS analysis and MDS. The microflotation results demonstrated that the SCIL has excellent collecting ability and selectivity for pyrrhotite against magnetite, compared with the traditional collector of sodium butyl xanthate (SIBX). Specifically. the flotation test results of mixed mineral shown that the S grade was reduced from 25.72 % of feed to 2.92 % of concentrate using SCIL as the collector, confirming its high efficiency. The analyses of zeta potential measurement and FTIR spectra indicated that SCIL was chemisorbed onto the pyrrhotite surface. The XPS results further confirmed that the C S bond of SCIL could be associated with S sites of the pyrrhotite surface, and Fe sites of the pyrrhotite surface might react with the C N or the C S bonds of SCIL. MDS further indicated that the adsorption of SCIL onto the pyrrhotite surface was much stronger than the SIBX.
危险品化学品经营许可证（带存储）