FLOTATION SEPARATION OF WOLLASTONITE FROM DIOPSIDE

The floatabilities of single mineral samples of wollas-tonite and diopside have been studied with addition, of a cationic collector,dodecyoamine hydrochloride (DDA·HCl) , and,modifiers. A mixture oftwo minerals was successfully separated,when DDA·HCl and tannicacid (as depressant)were used together. The interaction between tannicacid and wollastonite and diopside in the pulp and the adsorption of tannicacid on the surface of the two minerals was studide with the help of ultra-violet (UV) spectroscopy and X-ray photoelectron spectroscopy (XPS) ,re-spectively.     

Novel polyhydroxy cationic collector N-(2,3-propanediol)-N-dodecylamine: Synthesis and flotation performance to hematite and quartz

To enhance the performance of traditional cationic collector, a novel polyhydroxy amine collector N-(2,3-Propanediol)-N-dodecylamine(PDDA) was designed by introducing one propylene glycol group into dodecylamine(DDA). It was prepared by a nucleophilic substitution reaction, which showed better solubility and hydrophobicity than DDA and was firstly employed as the collector for the separation of hematite and quartz. Flotation tests showed that PDDA had an excellent flotation performance and signi...     

Selective depression action of taurine in flotation separation of specularite and chloriteOA

Chlorite, as the most representative gangue mineral associated with specularite, of which the separation of these two minerals is difficult. This paper investigated the depression effect of taurine on specularite/chlorite separation via flotation experiments, adsorption tests, contact angle measurements, Zeta potential detection, FT-IR measurements, and XPS analyses. The results of single mineral flotation indicated that chlorite could be depressed selectively by taurine with the recovery of les...     

Depression behaviors of N-thiourea-maleamic acid and its adsorption mechanism on galena in Mo-Pb flotation separation

In present study, a novel organic depressant N-thiourea-maleamic acid (TMA) was synthesized and applied as a galena depressant in the flotation separation of Mo-Pb ores. The depression behaviors of TMA were tested through flotation experiments. A wider separation window for single minerals over 90.0% was obtained at 30.0 mg/L TMA, confirming that TMA could depress galena significantly, while effected molybdenite floatability slightly. An effective separation was obtained for artificially mixed minerals and actual Mo-Pb ores. The adsorption mechanism on galena was revealed by UV–Vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR) analysis, contact angle tests and X-ray photoelectron spectroscopy (XPS) analysis. The zeta potentials of galena became more negative and the contact angle of galena dropped from initial 74.36° to 57.8° with 30.0 mg/L TMA depressant, inferring that TMA had adsorbed on galena surface. The analysis results of UV–Vis spectra, FT-IR and XPS gave further evidence that TMA might chemisorb on galena surface via Pb sites on galena surface and the thiourea group in TMA molecular structure, while the carboxyl group played a role of hydrophilicity.     

Studies of benzyl hydroxamic acid/calcium lignosulphonate addition order in the flotation separation of smithsonite from calcite

Flotation separation of smithsonite from calcite is difficult due to their similar surface properties. In the present study, a reagent scheme of depressant calcium lignosulphonate (CLS) and collector benzyl hydroxamic acid (BHA) was introduced in the flotation of smithsonite from calcite. Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS, which was opposite to the widely-used order that adding depressant prior to the collector. The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface, then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance, thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS. As a result, the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value, leading to the optimal flotation separation performance.     

Collecting property of diphosphonic acid for niobite

The effect of several collectors on the niobite synthetized under the condition of varying pH values and dosages were studied. The collecting property of several representative collectors was also investigated. The experimental result shows that diphosphonic acid is a good collector for niobite. Its recovery is about 84.24%-91.17% when the pH value of the pulp is less than 5.0 and the dosage of diphosphonic acid is 140 mg/L. The sequences of the selectivity and collecting capacity of the collectors were compared. Infrared absorption spectrum (IAS) and X-ray photoelectron spectroscopy (XPS) were used to detect and analyze the adsorption mechanism of diphosphonic acid on the surface of niobite. The IAS result indicates that diphosphonic acid is indeed adsorbed on the surface of niobite, and the XPS result shows that the binding energy of P2p peak of niobite treated by diphosphonic acid has changed 2.85 eV. It confirms that the adsorption belongs to a chemisorption type.     

Effect of hydroxamic acid polymers on reverse flotation of bauxite

The effect of hydroxamic acid starch (HAS) and hydroxamic acid polyacrylamide (HPAM) on the flotation of diaspore and kaolinite was investigated by flotation test. It is found that HAS depresses diaspore but activates kaolinite in acidic pulp,while HPAM activates both diaspore and kaolinite in the pH range of 2.0 - 10.5. The measurement of zeta potential shows that both HAS and HPAM can increase zeta potential of negatively charged diaspore, which indicates the existence of chemical bonding or hydrogen bonding between the reagents and diaspore.By covering the collector dodecyl amine(DDA) on diaspore surface, HAS increases the hydrophilicity of minerals and depresses the flotation of diaspore,however HPAM activates the flotation of diaspore by increasing the adsorption of DDA on diaspore surface.     

胍基阳离子捕收剂反浮选磷矿的性能与机理分析

为了研究磷矿反浮脱硅过程中,胍基阳离子磷矿捕收剂的作用机理,以N-椰油基-1,3-丙撑二胺、单氰胺、乙酸为原料制得一种阳离子表面活性剂,并用于傅里叶红外光谱仪表征,测试了该药剂与3种矿物作用前后的接触角、Zeta电位、红外光谱,进行了石英、白云石、胶磷矿的纯矿物浮选试验等。结果表明:该合成药剂属胍基阳离子表面活性剂,在广泛pH值范围内,对石英的捕收能力较强,对白云石次之,对胶磷矿较弱;在弱碱性下,对白云石捕收性能有所提高;相较白云石、胶磷矿,该药剂更易与石英产生吸附作用,使矿物表面呈现疏水性;接触角、Zeta电位、红外光谱测试结果说明与3种矿物的吸附主要是物理吸附。试验结果说明该胍基阳离子表面活性剂可以作为磷矿反浮脱硅捕收剂。     

Experimental and MD simulation of 3-dodecyloxypropanamine and 3-tetradecyloxypropylamine adsorbed onto quartz (1 0 1) surface

In this paper, two surfactants, 3-dodecyloxypropanamine (DOPA) and 3-tetradecyloxypropylamine (TOPA), were synthesized and used as collectors in the quartz micro-flotation in the laboratory. Micro-flotation tests, FT-IR, XPS measurements, and ab initio Molecular Dynamics (MD) simulations were conducted to research DOPA, TOPA, and dodecylamine (DDA)'s adsorption mechanisms onto quartz (1 0 1) surfaces. The results of micro-flotation show that the adsorption of DOPA and TOPA onto quartz surface is more robust than that of DDA. The zeta-potential result shows that the DOPA/TOPA was adsorbed on quartz through electrostatic attraction. Then, MD simulation adsorption models were built to compare the computational properties of the three surfactants, such as the radial distribution function, and the interaction energies between the collectors and the quartz cleavage surface. The interaction energies of surfactants (RNH₃⁺ or RNH₂) on the quartz surface explained why the pH range of DOPA/TOPA is wider than that of DDA. XPS analyses and MD simulations confirmed that DOPA bonded with the (1 0 1) surface of quartz through three types of hydrogen bonds between the NH₂ of DOPA and the O atom of quartz. The hydrogen bonds of type A and type C were the most likely type and more potent than those of type B.     

Effects of diphosphonic acid on ilmenorutile collecting property and research of action mechanism

The effects of several collectors and their dosage on pure ilmenorutile at different pH values were studied and the collecting strength of several representative collectors was investigated. The experimental results indicate that diphosphonic acid is a good collector for ilmenorutile and the recovery of ilmenorutile ranges from 90.87% to 91.70% when the pulp pH value is 2.0-4.0 and the dosage is 75 mg/L. The sequence of collecting ability for several collectors is as follows: diphosphonic acid > TF279 > cyclic alkyl hydroximic acid > benzyl arsenic acid > salicylic hydroximic acid > alkyl hydroximic acid. Meanwhile, IAS (infrared absorption spectrum) and XPS (X-ray photoelectron spectroscopy) were used to detect and analyze the action mechanism of diphosphonic acid on ilmenorutile. IAS results showed that the characteristic absorption peak relating to P = O as well as P-O vibration occurred between wave numeberl 140 and 1 032 cm ', and diphosphonic acid had adsorbed on the surface of ilmenorutile. XPS re     

Flotation performance of a novel Gemini collector for kaolinite at low temperature

How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing. In this work, a novel amino-based Gemini surfactant butadiyl-1, 4-bis (dimethyl dodecylammonium bromide) (BBDB) was prepared and first utilized as a novel collector for kaolinite flotation. Its flotation performance for kaolinite was compared with that of the common monomolecular surfactant 1-dodecylamine (DDA) by micro-flotation tests. The tests results indicated that 95% kaolinite recovery was obtained using 2.0 × 10⁻⁴ mol/L BBDB at 25 ℃, which was half of the dosage when DDA obtained the maximum kaolinite recovery of 81%. At extremely low temperature (0 ℃), 3.0 × 10⁻⁴ mol/L BBDB could still collect 91% kaolinite, while DDA showed a frustrating ability. The contact angle tests indicated that BBDB could still significantly improve the hydrophobicity of the kaolinite surface (contact angle 71.7°) than DDA (contact angle only 25.8°) at 0 ℃. The Krafft point comparison tests indicated that BBDB had a much lower Krafft point (below 0 ℃) than DDA. Fourier transform infrared spectroscopy (FTIR)-spectrum analysis and zeta potential measurements showed that BBDB was physically adsorbed on the surface of kaolinite through electrostatic interaction.     

Flotation of niobite, fersmite, and ilmenorutile

The flotation of niobite, fersmite, and ilmenorutile was studied using 3 collectors with various concentration and pulp pH. The collecting property of different representative collectors was investigated. Experimental results show that diphosphonic acid is an effective collector for valuable niobium-containing minerals. A flotation recovery of 90.87%-91.7% is obtained with 75 mg/L diphosphonic acid at pH 2-4. The chemical adsorption of diphosphonic acid on these 3 minerals’ surface might lead to the high re...     

SYNERGISTIC EFFECT OF MINERAL SURFACE CONSTITUENTS IN DEXTRIN ADSORPTION

Abstract:As part of a systematic research on the interaction mechanismbetween polysaccharides and mineral surfaces,we extend the studies ondextrin adsorption to real minerals such as oxides and salt-type minerals,based on previous studies of model systems(surface-modified quartz).Theminerals tested include hematite,rutile,fluorite,calcite,apatite,etc.Itis obseroed that dextrin adsorption on these minerals is strongly pH-depen-dent,with adsorption maxima appearing at pH values around the isoelec-tric points of the minerals,indicating interactions with surface metal hydroxide species.X-ray photoelectron spectroscopy(XPS)measurements re-veal electronic binding energy shifts or Auger parameter changes Of miner-al surface elements after dextrin adsorption,pointing to a chemical mecha-nism of interaction.Furthermore,it is observed that the reaction of miner-als with moderate amounts of fatty acids prior to dextrin addition resultsin an increase in dextrin adsorption,whereas excessive fatty acids do theOpposite     

铌钙矿的有效捕收剂及IAS和XPS光谱分析

研究了几种捕收剂在不同pH值和不同用量条件下对人工合成的铌钙矿的捕收效果，考察了苄基胂酸，苯乙烯膦酸，双膦酸，环烷基异羟肟酸，C7～9烷基异羟肟酸等几种代表性的捕收剂的捕收性能．用IAS和XPS检测和分析了双膦酸对铌钙矿的作用机理．试验结果表明双膦酸是铌钙矿的良好捕收剂，而且铌钙矿的回收率在双膦酸用量为20mg／L且矿浆pH值为2．5～5．0时，达到了83．27％以上．指出了这些捕收剂的选择性和捕收性能的顺序．IAS检测结果显示双膦酸在铌钙矿表面发生了吸附．同时XPS检测结果表明经双膦酸处理后的铌钙矿的P2p峰位键合能变化了3．85eV，证明了该吸附主要为化学吸附．     

Physical chemistry mechanisms of CDR system in sulphide mineral flotation

The flotation tests,zeta potential measurements,and Fourier transform infrared spectroscopy(FTIR) analysis on galena,sphalerite,and pyrite were studied in a collecting-depressing-reactivating(CDR) system.In this system,sulphide minerals were first collected and acti-vated by the collector,and then depressed strongly by Ca(OH)2 in a strong alkaline solution.Finally,they were reactivated by H2SO4.The flotation tests of pure minerals showed that in the Ca(OH)2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector.Hence,the flotability differences between them were reduced.However,in the H2SO4 re-activating process considerable differences in the flotability between galena and sphalerite/pyrite were produced.That is to say,galena was relatively easy to be reactivated by H2SO4,but sphalerite and pyrite were not reactivated at pH 11.The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values.The results of the FTIR spectra analysis indi-cated that the collectors already adsorbed on the mineral surface were removed partially by Ca(OH)2.     

Microscale insights into the influence of grinding media on spodumene micro-flotation using mixed anionic/cationic collectorsOA

Here, the influence of grinding media with different shapes on the flotation performance of spodumene and its potential mechanism from microscale insights was investigated using a single mineral flotation experiment, X-ray diffraction(XRD) test, scanning electron microscopy combined with energy dispersive spectrometry(SEM-EDS), atomic force microscope(AFM) and X-ray photoelectron spectroscopy(XPS).The flotation data indicated that under anionic/cationic(sodium oleate(Na OL)/DDA) collectors syste...     

Study of the interfacial interactions in the molybdenite floatation system

Interfacial interactions involving Van der Waals force, hydrophobic attractive force and hydration exclusive force were investigated in this paper. The interfacial interactive free energy of a series of interfaces occurring between minerals, water, collectors and bubble was calculated. The results show that a Van der Waals attractive force and a hydrophobic attractive force exist between each mineral and water interface. The hydrophobic attractive force between molybdenite and water is markedly weaker than the hydrophobic attractive force between gangue and water. The hydrophobic attractive force between collector molecules and water is the main driving force that causes the collectors to become dispersed in the pulp. The strong hydrophobic attractive force between molybdenite and the bubble interface is the basic reason for the natural floatability of molybdenite. The Van der Waals force between molybdenite and the collectors is attractive in water solution, but it is not the cause of the main force between them. The main force that results in the collection effect is a hydrophobic attractive force caused by the Lewis acid-base interaction at the molybdenite surface. A floatation experiment shows that the adsorption intensity of the collector on the molybdenite surface is not the crucial factor for molybdenite floatation. Rather, the dispersing capability of the collector in the water phase and its selectivity for the various minerals in the floatation system are more important.     

大豆球蛋白吸附在空气-水界面上的流变学研究

采用轴对称滴形分析法研究了大豆球蛋白吸附在空气-水界面上的界面流变特性，主要检测了在有代表性的浓度和pH值条件下其表面张力和表面膨胀特征参数随吸附时间的变化。试验表明，随着吸附时间的延长，大豆球蛋白吸附在空气-水界面上的表面张力降低，膨胀模量增大而相角减小，这主要与蛋白质在界面上的吸附、展开和（或）蛋白质间的相互作用有关。大豆球蛋白在空气-水界面上的吸附随着初始体相蛋白浓度的增加而加快，受体相pH值的影响很大。从流变学的角度分析，大豆球蛋白吸附到空气-水界面上所形成的粘弹性的吸附膜实际上是弹性的。     

含钙矿物浮选中的本体沉淀及其对矿物可浮性的影响

通过浮选实验和富里叶变换红外光谱及X光电子能谱的测试表明,在含钙矿物浮选体系中,矿物表面的吸附物与本体沉淀的性质是有差别的,本体沉淀没有粘附于矿物表面起疏水化作用,它对浮选没有贡献。但在过饱和体系中的吸附密度测定时,本体沉淀的干扰是不容忽视的。     

A new synthetic chelating collector for the flotation of oxidized-lead mineral

A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective collector for the flotation of cerussite mineral. The synthetic method utilized the Mannich-type reaction of an N-monosubstituted thiourea, an aldehyde, and triphenyl phosphate in glacial acetic acid solution. The experimental results of flotation of the cerussite mineral show that the collector has stronger collecting ability and higher selectivity in a neutral and a slightly alkaline medium, especially in the pulp of pH=8. Using the measurements by infrared spectroscopy （IR） and X-ray photoelectron spectroscopy （XPS） of the cerussite mineral, the collector, as well as the cerussite treated with the collector, the flotation mechanism of cerussite has been discussed. It is concluded that the adsorption of collector on cerussite is a chemical adsorption through the electron donor atoms of the collector chelating the Pb （ Ⅱ ） of cerussite to form chelate.