An in situ ATR-FTIR study of mixed collectors BHA/DDA adsorption in ilmenite-titanaugite flotation system

This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investigated through in situ attenuated total reflectance Fourier transform infrared(ATRFTIR)spectroscopy combined with the two-dimensional correlation spectroscopy(2D-COS)and X-ray photoelectron spectroscopy(XPS).It has been found that BHA/DDA mixed collectors successfully separate ilmenite from titanaugite at a molar ratio of 8:1.Zeta potential experiments suggested that,in the presence of mixed collector system,the BHA-DDA complex adsorbed on the ilmenite surface via the chemically adsorbed BHA and the electrostatically adsorbed DDA,however,the complex adsorbed on the surface of titanaugite unstably.According to in situ ATR-FTIR combined with 2D-COS and XPS results,the interface assembly mechanism of BHA/DDA is summarized as:the function group of BHA molecules first binds to the metal sites on minerals to form bidentate ligand,then DDA co-adsorbed with BHA on the surface of minerals through hydrogen bonding.DDA may change the adsorption modes of some BHA on the ilmenite surface from four-membered ring to five-membered ring,while the modes on the titanaugite surface is true opposite.Finally,recommended adsorption configurations of the BHA/DDA complex on the two mineral surfaces are proposed.

Removal of dolomite and potassium feldspar from apatite using simultaneous flotation with a mixed cationic-anionic collector

This study aims to investigate the effect of a cationic-anionic mixed collector(dodecyltrimethyl ammonium bromide/sodium oleate(DTAB/NaOL)on the selective separation of apatite,dolomite,and potassium feldspar.Herein,several experimental methods,including flotation experiments,zeta-potential detection,microcalorimetry detection,XPS analysis and FTIR measurements,were used.The flotation tests showed that dolomite and potassium feldspar can be successfully removed from apatite simultaneously when the molar ratio of DTAB to NaOL was 2:1 with pH 4.5.Zeta-potential and microcalorimetry detection suggested that NaOL and DTAB were adsorbed on the surface of dolomite and potassium feldspar respectively,and part of NaOL and DTAB formed co-adsorption on the surface of potassium feldspar to enhance the floatability of potassium feldspar.The XPS and FTIR spectra analysis demonstrated that the cationic collector,DTAB,was first adsorbed on the surface of potassium feldspar through electrostatic attraction in the DTAB/NaOL mixture system.Subsequently,the anionic NaOL collector and cationic DTAB collector form an electron neutralisation complex,thereby resulting in co-adsorption on the surface of potassium feldspar.NaOL was chemically reacted and adsorbed on dolomite surface,but almost no collector was adsorbed on apatite surface.Finally,the adsorption models of different collectors on mineral surface were obtained.

Study on Mixing Power and Mathematics Model of Flotation Cell

The mixing mechanism of flotation cells is studied, and the mathematics model for mixing power is established. The model can be used to calculate the power consumption of the whole mechanism, as well as the power composition of each individual part. The power magnitude and the ratio between the macroscopic convection diffusion and the turbuleut diffusion, which are closely related to the performance of a cell, are also analyzed.

Recovery of molybdenum and copper from porphyry ore via iso-flotability flotation

A copper-molybdenum iso-flotability flotation process has been developed to efficiently improve the recovery ofmolybdenite from Duobaoshan porphyry Cu-Mo ores.The effects of flotation approach,type of collector,feed particle sizedistribution,rougher pH value and reagent dosage on the recovery of molybdenite were evaluated systematically.The results suggestthat compared with kerosene and diesel oil,transformer oil has stronger dispersion capability in water media and better flotationselectivity for molybdenite,providing a higher molybdenum recovery under low reagent dosage.Moreover,compared with bulkflotation approach,the iso-flotability flotation approach using transformer oil as a collector can obtain superior Mo recovery(90.77%)and grade(0.80%)in the cleaner concentrate,and increase the Mo recovery and grade by over18%and5%in the final Moconcentrate,respectively.The results of commercial flotation further indicate that the iso-flotability flotation approach is a rationaland effective route to beneficiate the porphyry Cu-Mo ores.

CFD simulation of single-phase flow in flotation cells:Effect of impeller blade shape,clearance,and Reynolds number

A series of numerical simulations of turbulent single-phase flows are performed to understand the flow and mixing characteristics in a laboratory scale flotation tank.Four impeller blade shapes covering a wide range of surface areas and lip lengths are considered to highlight and contrast the flow behavior predicted in the impeller stream.The mean flow close to the impeller is fully characterized by considering velocity components along the axial direction at different radial locations.Normalized results suggest the development of a comparatively stronger axial velocity component for a blade design with the smallest lip length,called big-tip impeller here.Normalized turbulent kinetic energy profiles close to the impeller reveal the existence of an asymmetric trailing vortex pair.The highest turbulence kinetic energy dissipation rates are observed close to the impeller blades and stator walls where the radial jet strikes the stator walls periodically.Furthermore,liquid phase mixing in the flotation cell is studied using transient scalar tracing simulations providing mixing time data.Finally,pumping capacity and efficiency of different impeller designs are calculated based on which the impeller blade design with a rectangular blade design is found to perform most efficiently.

STUDY ON MECHANISM OF MIXED COLLECTORS IN SEPARATION OF FELDSPAR AND QUARTZ

Acidless and fluoless flotation is a new method for sepa-rating feldspar from quartz at the natural pH value of tap water in the ab-sence of any acid and fluoride and other inorganic reagents. The paper discusses the mechanism of mixed collectors in separation of feldspar and quartz by means of mono-mineral flotation experiment, determination of surface-tension, analisis of fluorescence, infrared spectrum, Auger elec-tron sepectrum , and quantum chemistry calculation.

Flow of gas-liquid-solid system and its application in packed flotation column

A packed flotation column, which is packed with multiple board ripple packings, was described. Based on comprehensive steady state models, chemical reactor developed previously in chemical engineering subjects, have been extended to packed flotation column for mineral separation. The experimental results verify that tanks in series model is better than axially dispersed plug flow model to describe flow pattern in the collection zone of column by RTD (residence time distribution), and the error of experimental data and calculated data of both models are 0.07% ～ 0.1% and 0.18% ～ 0.45% respectively. And, RTD of gas phase was also considered, results also show that gas in the whole column appears plug flow. The cleaning process through adding wash water in froth zone of column was described, and the effect of superficial air velocity and superficial wash water velocity on the cleaning action of froth zone were discussed. Flotation experiment for single column was conducted for phosphate ores. The recovery for P 2O 5 was 85.8%, and the grade was 26.8%.

钾混盐粒度组成对其转化浮选的影响机制研究

硫酸钾对中国粮食生产至关重要,为加快硫酸钾的高效制备,保障中国农业的稳定发展,对合成硫酸钾的关键中间产物软钾镁矾的制备进行研究。首先针对罗布泊盐湖钾混盐粒度易随季节变化而差异显著导致软钾镁矾制取效率低的问题,通过磨矿-转化-浮选工艺探究钾混盐粒度组成对其转化浮选的影响机制,结果表明,钾混盐粒度越细,转化程度越高且转化产物粒度也越细。钾混盐磨矿3 min后对应的<0.074 mm转化产物占比达42.69%,且钾离子主要分布于该粒级物料中。同时,钾混盐粒度对软钾镁矾的浮选行为具有显著影响,其浮选效率随钾混盐粒度的减小呈先上升后下降趋势,当钾混盐<0.250 mm粒级占比为79.78%时,软钾镁矾制取效率最高。此外,还进行了转化产物粒度对软钾镁矾和氯化钠浮选分离的影响研究,结果表明,转化产物粒度越细,软钾镁矾和氯化钠浮选速率常数差值越小,在<0.074 mm时仅为0.0945 min-1,此时二者难以有效分离。研究结果对软钾镁矾生产工艺调控和优化具有重要的指导意义。

云南某难选氧硫混合铜矿石的新型药剂浮选试验研究

云南某氧硫混合铜矿石氧化率高、铜矿物嵌布粒度细、钙镁等易泥化脉石含量高,为充分利用该矿石资源,采用“铜硫混合浮选—混合精矿铜硫分离—混浮尾矿再选氧化铜”流程开展了新型药剂浮选试验研究。在磨矿细度为-0.074 mm占85%的条件下,应用新型捕收剂KM23和起泡剂730A选出混合铜硫精矿,应用组合抑制剂石灰+LY分离浮选出硫化铜矿物,应用组合活化剂硫化钠+氯化铵浮选出氧化铜矿物,最终获得铜品位为22.56%、铜回收率为42.91%的硫化铜精矿和铜品位为20.64%、铜回收率为27.18%的氧化铜精矿,铜综合回收率为70.09%。有价金属银在铜精矿中富集,硫化铜精矿含银145.7 g/t、氧化铜精矿含银91.17 g/t。研究结果可作为该矿石开发利用的依据。

内蒙古某含碳高硫锌锡矿石选矿试验研究

内蒙古某含碳高硫锌锡矿石锌品位1.02%、锡品位0.86%,硫和碳含量分别为14.02%、1.68%。矿石矿物组成较复杂,主要有用矿物为闪锌矿、锡石和黄铁矿,脉石矿物主要为石英、绿泥石和绢云母等。为确定矿石合理的开发利用工艺,采用预先脱碳—浮重联合工艺流程开展选矿试验研究。结果表明,矿石经预先脱碳、1粗1扫1精锌硫混选、1粗1扫3精锌硫分离浮选流程处理,闭路试验可得到Zn品位为45.16%、Zn回收率为71.19%的锌精矿,S品位为46.92%、S回收率81.91%的硫精矿;浮选尾矿采用摇床重选,经粗选、精选、复选和中矿再选,可获得Sn品位45.52%、Sn回收率81.99%的锡精矿,以及Sn品位3.13%、Sn回收率11.09%的锡中矿。所设计试验流程较好地解决了矿石中有机碳对浮选的不利影响,综合回收了有价矿物,可为同类矿石的开发利用提供理论借鉴。

选铁尾渣铜、钴、硫综合回收工艺研究及半工业调试

尾渣的二次资源化利用对缓解资源紧张、矿业可持续发展具有十分重要的意义。秘鲁某选铁尾渣量大,含有较高的Cu、Co、S等有价元素,其金属矿物在海水富离子介质条件下受溶解蚀变及上游选厂铁精矿脱硫降锌作业大量浮选药剂深度活化,分离回收难度较大。通过对矿石性质研究,采用阶段磨矿-混合浮选-铜与硫钴分离的工艺,在实验室小型试验的基础上进行半工业调试,取得较好的Cu、Co、S综合回收效果。

分子动力学模拟在矿物浮选中的研究进展

浮选药剂是实现矿物选择性分离的关键,尤其是组合药剂在矿物浮选中应用广泛。药剂性能的发挥与其在三相界面的微观吸附结构及组装行为密切相关,从微观层面探索药剂的作用机制成为近年来的研究热点。随着高性能计算的飞速发展,分子动力学模拟逐渐成为研究矿物浮选行为的有利工具。本文以硅酸盐矿物浮选体系为例,论述近年来组合捕收剂在硅酸盐浮选分离中的应用,阐述研究者对药剂在水溶液体系、气-水界面及矿物-水界面的分子动力学模拟研究进展,指出目前模拟研究中存在的问题,并对分子动力学在矿物浮选中的应用发展前景进行展望。

河南某含金银硫化铜矿选矿试验研究

对河南某含金银硫化铜矿开展了工艺矿物学和选矿试验研究。结果表明:矿石中主要有用元素铜含量为0.82%,伴生的有益组分为硫、金和银,主要有用金属矿物为黄铜矿、辉铜矿和黄铁矿,脉石矿物主要为石英。试验以新型药剂TB1021为铜硫分离捕收剂,采用混合浮选—铜硫分离工艺获得铜精矿和硫精矿,硫精矿再经摇床重选回收部分微细粒铜精矿。混合浮选采用丁基黄药和丁铵黑药组合捕收剂,总药剂用量为120 g/t,采用一粗两精三扫工艺流程;铜硫分离浮选采用新型捕收剂TB1021,采用一粗三精三扫工艺流程。最终获得铜品位为15.21%、铜回收率为80.13%,金品位为3.02 g/t、金回收率为66.51%,银品位为160.43 g/t、银回收率为41.82%的铜精矿,以及硫品位为49.13%、回收率为54.34%的硫精矿。

组合捕收剂协同增效机制及其在浮选中的应用进展

组合捕收剂的协同增效对改善单一捕收剂性能缺陷有着重要作用,通过广大研究者针对组合捕收剂的最新研究,详细阐述了组合捕收剂协同增效的具体机制和原理,主要分为共吸附机理、电荷补偿机理、疏水强化机理和捕收剂性质互补机理。针对组合捕收剂在浮选中的不同应用,分类描述了不同种类组合捕收剂在浮选中的最新使用情况。针对组合捕收剂协同增效现有研究的不足,提出建立理论计算与分析表征相结合的捕收剂间协同增效机制研究平台,发展新的分析表征技术,加强捕收剂间促溶、促分散等方面的基础研究,建立对应的构效关系,并使用大数据、机器学习和人工智能,这将对高效组合捕收剂的研究有着重要意义。

四川大陆槽稀土尾矿回收萤石实验

这是一篇矿物加工工程领域的文章。本文以德昌大陆槽稀土选矿尾矿为研究对象,开展了萤石回收的选矿实验研究,确定了该尾矿中萤石回收的“浮选脱硫-混合浮选-萤石、锶钡浮选分离”选矿工艺流程和药剂制度,在浮选实验中使用了新型捕收剂MQY与高效抑制剂DC-2,在对萤石高效捕收的同时实现了萤石与脉石矿物的精准分离,最终全流程实验获得了CaF_(2)品位94.39%,回收率51.41%的萤石精矿,实验指标较为理想。本文验证了从大陆槽稀土尾矿中回收萤石具有较好的可行性,最终确定的选矿工艺流程较为合理,实验指标较为良好,可作为大陆槽稀土尾矿中萤石资源利用回收的技术依据。

云南某贫细硫化铜矿石选矿工艺优化研究

云南某低品位细粒嵌布的铜矿石铜、硫品位分别为0.161%和9.704%,有价铜矿物嵌布粒度细,铜硫分离富集难度较大。为实现该硫化铜矿石资源的高效开发利用,在选厂原选矿流程及原矿工艺矿物学研究基础上,进行了系统的磨浮试验。结果表明:矿石采用磨矿—1粗2扫铜硫混合浮选—混浮粗精矿再磨—1粗3精2扫铜硫分离浮选闭路流程处理,可获得铜品位14.69%、铜回收率63.15%的铜精矿,硫品位29.16%、硫回收率75.10%的硫精矿,试验铜精矿品位较现场提高近3个百分点,铜回收率提高15个百分点以上,显著优于现场生产指标,达到了理想的综合回收铜硫效果。研究结果可作为工艺流程优化的依据。

十二醇对黑龙关难浮煤泥浮选的强化作用研究

为提高难浮煤泥的精煤回收率,以黑龙关煤泥为研究对象,选用正癸醇、十二醇、十四醇三种长链脂肪醇,采用直接添加和与煤油复配的方式,进行了浮选试验。借助接触角、XPS、润湿热,分析了长链脂肪醇的作用机理。结果表明,无论是单独添加还是配制成复合捕收剂,十二醇的浮选效果最好,复配可以节省药剂用量。在捕收剂用量2 kg/t时,与煤油相比,15%比例复配药剂可将精煤产率提高23.89%,尾煤灰分提高9.53%,可燃体回收率提高28.23%。此外,十二醇处理过的煤泥接触角增加12.44°,润湿热降低5.37 J/g,亲水基团O—C=O含量降低3.25%。十二醇通过降低煤粒亲水性官能团含量,提高煤粒表面疏水性,十二醇复配药剂通过十二醇极性成分和煤油非极性成分的协同作用增大煤表面疏水面积提高浮选效果。

HYIC捕收剂强化鞍千混合磁选精矿反浮选效果试验

鞍千选矿厂为了优化选别工艺中的反浮选效果,取浮选入选的混合磁选精矿进行浮选试验,进行了抑制剂、活化剂、捕收剂用量及常规捕收剂TD-Ⅱ与新型捕收剂HYIC浮选效果对比试验。试验结果表明:固定矿浆pH值为11.5、抑制剂淀粉用量1200 g/t、活化剂CaO用量500 g/t、粗选捕收剂用量800 g/t、精选捕收剂用量300 g/t,采用常规捕收剂TD-Ⅱ时,闭路试验获得了精矿铁品位68.20%、铁回收率88.73%的选别指标;采用新型捕收剂HYIC时,闭路试验获得了精矿铁品位68.25%、铁回收率90.04%的选别指标;使用捕收剂HYIC比采用捕收剂TD-Ⅱ所获得的浮选精矿产率、铁品位、铁回收率分别高0.91,0.05,1.31个百分点,捕收剂HYIC可以强化反浮选效果,提高选厂的经济效益。

微波预处理对中性条件下石英和长石浮选行为的影响研究

针对石英与长石难以有效浮选分离的问题,试验采用微波预处理的方法增大石英和长石表面性质的差异。研究在中性条件下油酸钠和十二胺为混合捕收剂、六偏磷酸钠为抑制剂条件下微波预处理分别对石英与长石浮选回收率的影响。试验结果表明,微波后的浮选回收率差值提高了11.87%。药剂吸附试验和Zeta电位测定结果表明,微波后石英对药剂的吸附能力下降,Zeta电位上升;而长石对药剂吸附能力上升,Zeta电位下降。说明微波预处理改变了矿物对药剂的吸附量,并增大了石英与长石表面性质的差异,提高了分选效果。

焙烧预处理强化钼铜分离试验及机理研究

为解决钼铜混合精矿的铜钼浮选分离难题,以某选厂钼铜混合精矿为研究对象,探究了焙烧预处理对钼、铜浮选分离效果的影响。结果表明:焙烧预处理能有效改善钼铜混合精矿的浮选分离效果,确定的适宜焙烧预处理条件为焙烧温度250℃,焙烧时间30 min。预处理产品采用1粗2精1扫浮选流程处理,可获得钼精矿钼品位为44.30%、钼回收率为36.58%,铜精矿铜品位为14.23%、铜回收率为69.62%。焙烧产品的XRD和SEM-EDS分析结果表明,样品在焙烧过程中,主要矿物辉钼矿和黄铜矿均可发生氧化反应;当焙烧温度为250℃时,黄铜矿的表面氧化程度远高于辉钼矿,从而增大了两者可浮性差异,为有效分离铜、钼矿物分离创造了条件。