Yuhang Che,Wei Chen,Sheng Liu,Guangsheng Zeng,Guangyi Liu
Talc has long been a problematic gangue mineral in sulfide ore flotation due to its natural hydrophobicity. The as-investigated anionic depressants which reacted with the Mg sites on the edge plane of talc always exhibited limited effects because the negatively charged talc particle at pH > 5.0 showed electrostatic resistance for the anion adsorption. Thus, an electrically neutral reagent, fenugreek gum, was introduced as a highly efficient talc depressant in comparison with the sodium carboxymethylcellulose and sodium alginate, coupled with the surface detections on the selective depressant mechanism between chalcopyrite and talc. The micro-flotation results showed that fenugreek gum could selectively depress the talc flotation at lower dosage and wider pH range than sodium carboxymethylcellulose and sodium alginate, suggesting a more efficient depressant role. Surface detection implied that fenugreek gum selectively interacted with the basal plane of the talc surface and remarkably decreased its hydrophobicity mainly through physical adsorption originated from the hydrogen-bonding between the OH group and the [SiO 4 ] tetrahedron. Fenugreek gum adsorbed onto talc with much larger capacity than on chalcopyrite, and had little influence on the adsorption density of collector adsorption on chalcopyrite, indicating the highly efficient selectivity of fenugreek gum toward talc depression.
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.
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）