Separation of Oil from Wastewater by Column Flotation

A new type of device,a dissolved-air flotation column,was developed for separation of oily wastewater. The unique design idea of the dissolved-air flotation column is the combined use of dissolved-air flotation and column flotation. The dissolved air release occurred within the column separation system. As a potential application the column was investigated for its performance in separating emulsified oil droplets in oily wastewater. A high separation efficiency was obtained in a series of tests. The aeration performance of the bubble generator used in the dissolved-air flotation column was also studied in particular.

Comparison of mechanical and column flotation performances on recovery of phosphate slimes in presence of nano-microbubbles

Fine particle flotation has been one of the main problems in many mineral processing plants.The bubble particle collision rate is very low for fine particles,which reduces flotation efficiency.Also,the existence of slimes is,generally,detrimental to the flotation process,affecting the selectivity and the quality of the concentrates.Besides,it causes an increase in reagents consumption.Hence,in most of processing plants,some of these particles are transmitted to the tailing ponds to reduce the effects of these problems and increase the selectivity of the process.Esfordi phosphate plant in Iran loses more than 30%of its capacity as particles with d 80 finer than 30μm.These fine particles with 15.9%P_(2)O_(5)content are transferred to tailing dam.Processing of fine particles is very important for phosphate industry from economic and environmental aspects.This study addressed the processing of fine tailings(slimes)from a phosphate ore concentrator via flotation,despite the traditional view that ultrafine particles do not float.Phosphate flotation performances in the presence and absence of nanobubbles(NBs)in both mechanical and column cells were compared according to the metallurgical results of the process.NBs(generated by hydrodynamic cavitation)have interesting and exclusive properties such as high stability,durability and high surface area per volume,leading to increase of their utilization in mining-metallurgy and environmental areas.The results of this study revealed that,in the absence of NBs,a concentrate containing 26.9%P_(2)O_(5)with a recovery of 29.13%was obtained using mechanical cells in comparison to 31.6%P_(2)O_(5)with a recovery of 32.74%obtained using column flotation.In the presence of NBs,the recoveries of the concentrate of the mechanical and column flotation increased to 40.49%and 41.26%with 28.47%and 30.43%P_(2)O_(5)contents,respectively.Comparative study showed that the column flotation was almost more efficient for processing the phosphate ore in the presence of the NBs,and had thicker froth layer compared to the mechanical flotation.

Particle Residence Time in Column Flotation Based on Cyclonic Separation

The cyclonic static micro-bubble column flotation (FCSMC) is an effective separation device for fine particle treatment. The high mineralization rate and short flotation time of this equipment can be attributed to its unique cyclonic force field. It also has been observed that the presence of a cyclonic force field leads to a lower bottom separation size limit and a reduction of unselective entrainment. The collection zone of the column is considered to consist of two parts,a column separation zone and a cyclonic zone. Total recovery of the collection zone was developed. For our study,we analyzed the particle movement in the cyclonic zone. Particle residence time equations for the cyclonic zone were de-rived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.

Cyclonic separation process intensification oil removal based on microbubble flotation

The cyclonic-static microbubble flotation column has dual effects including the cyclonic separation and floatation separation with the characteristics of the small lower limit of the effective separation size, short separation time, large handling capacity, and low operation cost. It shows significant advantages in the oily wastewater treatment field, especially the polymer flooding oily wastewater treatment aspect. In this paper, the cyclonic separation function mechanism of the cyclonic-static microbubble flotation column was studied, the impact of the parameters including the feeding rate, aeration rate, circulating pressure, and underflow split ratio on the cyclonic separation efficiency was investigated, and the cyclonic separation efficiency model was established as well. In addition, by applying the Doppler Laser Velocimeter (LDV) and Fluent simulation software, the test and simulation to the single-phase flow velocity field of the cyclonic separation section of the cyclonic-static microbubble flotation column were carried out, and the velocity distribution rule of the cyclonic separation section was analyzed under the singlephase flow conditions.

Semi-industrial experimental study on bauxite separation using a cell-column integration process

The cyclonic-static micro-bubble flotation column （FCSMC） is a highly efficient mineral processing equipment. In this study, a cell-column （FCSMC） integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon （A/S） mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of ＂fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns＂. Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-coltmm integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

Adsorption mechanism of sodium oleate and styryl phosphonic acid on rutile and amphibole surfaces

A reagent combination of sodium oleate(NaOl)and salicyl hydroximic acid was employed as the roughing and scavenging collectors,whereas styryl phosphoric acid(SPA)and octanol were employed as the cleaning collectors.Results of bench-scale flotation demonstrate that the dosage of SPA can be reduced by about 80%,and that a better flotation index can be obtained using the proposed reagent system.The results of adsorption amount and contact angle measurements indicate that the rutile surface adsorbed not only a large amount of residual NaOl but also SPA and a small amount of NaOl remained on the amphibole surface in strong acidic solution.The hydrophobic difference between rutile and amphibole surfaces was therefore amplified in cleaning,and their further separation became much easier consequently.

金矿选矿技术研究进展

为助力国内金矿选矿技术攻关,实现金矿资源的高效、合理化开发利用,通过梳理国内金矿资源分布情况及典型黄金矿山的重选法、浮选法、联合工艺和预处理选矿工艺的研究现状,针对性地总结了含碳高砷、高硫、难处理金矿的研究方向,为实现难选金矿资源的高效、合理化开发利用提供了思路。

弓长岭某磁铁矿高效制备超级铁精矿研究

超级铁精矿作为一种高附加值的新型材料,具有巨大的发展潜力。弓长岭某磁铁矿TFe品位45.62%,SiO_(2)是其主要的脉石成分,含量为33.21%,有害元素P、S含量较低。矿石中的铁主要赋存在磁铁矿中,占全铁的95.05%。矿石中磁铁矿粒度较粗,主要分布在+0.074mm,分布率为82.37%。磁铁矿主要以单体形式产出,部分微细粒石英以包裹、反包裹和细脉状嵌布于磁铁矿中,较难完全解离。为实现该矿石的高值化利用,开展了超级铁精矿制备工艺研究。结果表明,采用阶段磨矿—阶段磁选—反浮选工艺处理该磁铁矿石,在一段磨矿细度为-0.074mm占65%、二段磨矿细度为-0.025mm占90%、反浮选工艺中粗选和精选的捕收剂用量均为25g/t的条件下,可以获得TFe品位72.35%、回收率为81.03%、SiO_(2)含量为0.17%、酸不溶物为0.19%、其他杂质含量微量的高品质超级铁精矿,以及TFe品位71.37%、回收率为6.07%的高纯铁精矿和TFe品位60.26%、回收率为6.71%的普通铁精矿,为磁铁矿的高附加值和梯级化利用提供了技术依据。

基于苯甲羟肟酸的三元组合捕收剂浮选分离钛铁矿与橄榄石机理研究

钛铁矿与橄榄石表面金属位点性质高度相似而难以分离。采用三氯化铝(Al)、苯甲羟肟酸(BHA)、油酸钠(NaOL)组装新型三元组合捕收剂(ABN),用于浮选分离钛铁矿和橄榄石。单矿物浮选实验表明,在Al、BHA和NaOL的摩尔比为2∶3∶1、pH值=8的条件下,钛铁矿回收率达90.4%,橄榄石回收率为25.9%。相比单一BHA,钛铁矿回收率提升了58.17百分点。表面Zeta电位测定和XPS分析表明,ABN在Ti(OH)、Fe(OH)位点发生化学吸附导致其表面电位正移了47.32 mV,在橄榄石表面只有少量电性吸附。粉末接触角测量结果显示,ABN使钛铁矿与橄榄石的表面接触角差异由1.01°提升至20.41°。ABN在钛铁矿表面的选择性吸附,增大了其与橄榄石的润湿性差异,利于实现两种矿物的浮选分离。

低品位胶磷矿重选中矿浮选试验研究及重浮联合分选工艺

低品位胶磷矿经强化离心重选抛尾后得到了部分合格精矿,但其重选中矿的量仍然较大、品位仍然较高。为更充分地回收磷矿,基于对重选中矿的元素组成、矿物组成和嵌布情况分析,进行了浮选试验,并通过FTIR分析了反浮选的机理,最后将强化离心重选与浮选研究结果加以整合,确定采用重浮联合工艺。研究结果表明:重选中矿的P_(2)O_(5)品位为17.12%,主要矿物为磷灰石、白云石和石英,其细粒级解离相对较充分,但粗粒级(>0.074mm)仍有部分未解离。对重选中矿进行磨矿后浮选,正浮选中随着碳酸钠用量的增加,精矿品位逐渐上升、产率逐渐下降,随着捕收剂ZF-1用量的增加,精矿产率不断上升、品位不断下降,两者最佳用量分别为3.0,1.5kg/t,此时精矿产率和品位分别为67.81%和21.41%;反浮选中随着硫酸用量的增加,精矿产率不断下降,品位则先升高而后趋于稳定,随着捕收剂ZF-2用量的增加,精矿产率不断下降,但下降速度逐渐减小,精矿品位则先升高而后趋于平稳,两者最佳用量分别为5,0.9kg/t,此时精矿产率和品位分别为60.49%和26.97%。FTIR测试发现,最佳试验条件下ZF-2与胶磷矿未发生CO_(3)^(2-)明显吸附,而在白云石表面则发生了化学吸附,并对白云石本身的起到了良好的遮蔽效果,因而起到了反浮选脱除碳酸盐类矿物的目的。将重选与浮选整合,得到重浮联合的最终精矿和最终尾矿,产率和品位分别为39.06%和25.12%,60.94%和8.51%,整体效果良好。

袁家村微细粒难选磁赤混合铁矿石提铁降硅试验研究

袁家村铁矿选矿厂原生产工艺流程获得的铁精矿TFe品位仅65%左右、SiO_(2)含量达4%~5%,难以满足市场对高品质铁精矿的需求。为此,在详细分析生产流程中混合磁选精矿性质的基础上,采用卧式搅拌磨机细磨—弱磁选+强磁选—反浮选工艺流程开展了提铁降硅试验研究。对TFe品位42.44%、SiO_(2)含量35.42%的混合磁选精矿,在磨矿细度为-0.045 mm占97%情况下,全流程试验获得了产率53.87%、TFe品位67.87%、SiO_(2)含量1.96%、TFe回收率86.15%的高品质铁精矿;磨矿细度为-0.045 mm占94%情况下,适当增大捕收剂RA用量,可获得产率54.76%、TFe品位67.14%、SiO_(2)含量2.09%、TFe回收率86.63%的高品质铁精矿。研究结果可作为选矿厂提铁降硅工艺流程优化决策依据,对类似性质难选铁矿石的高效开发利用具有参考价值。

河北某普通磁铁矿制备超纯铁精矿试验研究

河北某普通磁铁矿TFe品位为65.25%,矿石性质结构简单,具有制备超纯铁精矿的潜力。研究采用多元素及X射线衍射图、物相分析等方法对原矿进行了工艺矿物学研究,并在此基础上对其进行了提纯试验。结果表明,原矿经过弱磁选粗选后,在磨矿细度-0.038 mm占85%的条件下经弱磁选再选、磁选柱精选得到TFe品位为71.31%的磁选柱精矿以及TFe品位68.12%、产率为3.32%的磁选柱铁尾矿。通过进一步考察药剂制度和工艺流程对铁矿精矿品位、回收率等选别指标的影响,确定了合适的药剂制度。而后磁选柱精矿经1粗3精反浮选降硅工艺试验流程,最终可获得含TFe品位71.95%、综合回收率为80.50%的超纯铁精矿,浮选尾矿TFe品位68.17%符合普通铁精矿标准。通过对选别产品进行试样化学成分分析及残余药剂测定,进一步证明该工艺流程可以实现超纯铁精矿的制备。该工艺在抛尾率为10.79%条件下,将原矿样的73.04%转化为超纯铁精矿,对这一地区超纯铁精矿的制备具有重要的指导意义,也为国内其他地区磁铁矿制备超纯铁精矿的研究提供了一定的参考价值。

新疆某锂钽铌铍多金属矿选矿试验研究

对新疆某锂品位0.68%的锂钽铌铍多金属矿进行了选矿试验研究。工艺矿物学研究结果表明,该矿石中锂矿物以锂辉石为主,钽铌矿物含量较低。采用磁选-重选回收钽铌、浮选回收锂的工艺流程,可得到Ta_(2)O_(5)品位17.110%、Nb_(2)O_(5)品位19.670%,回收率分别为41.69%、42.63%的钽铌精矿和Li2O品位5.12%、Li2O回收率75.21%的锂精矿。

陕南某铁尾矿中重晶石的高效回收工艺

陕南某铁尾矿中含有12%左右的重晶石,常规选别工艺难以回收。结果表明:重选-浮选联合流程是高效回收该尾矿中重晶石的有效途径之一,通过螺旋溜槽+摇床联合的重选工艺可预先抛除90%以上的尾矿,该技术大幅简化了工艺流程和设备台(套)数。重选精矿采用“一粗四精二扫中矿顺序返回”的浮选分离后可获得BaSO4品位为93.2%、回收率为75.3%的最终精矿产品,该产品达到HG/T 3588—1999优等品级别。

刚果(金)某锂辉石选矿试验研究

刚果(金)某锂辉石Li_(2)O品位0.86%,属于低品位难选锂矿石。为实现该锂辉石高效综合利用,对其开展浮-磁联合试验研究。研究结果表明:在磨矿细度-0.074 mm占比75.0%,碳酸钠用量500 g/t,氯化钙用量140 g/t,氢氧化钠球磨机内用量700 g/t、浮选槽内用量200 g/t,捕收剂组合A(氧化石蜡皂与油酸质量比为1∶3)用量1650 g/t条件下进行一粗两扫三精一磁闭路试验,可获得Li_(2)O品位为5.67%、Li_(2)O回收率为77.71%的脱磁产品,Li_(2)O品位为4.51%、Li_(2)O回收率为10.51%的磁性产品。试验指标良好,为锂辉石资源综合利用提供重要参考依据。

浮选柱法从浮选尾矿中回收微细粒级白钨矿的研究

为提高钨资源利用效率，针对湖南安化湘安钨业公司白钨浮选尾矿中微细粒级在浮选机中未能有效分选的特点，利用微泡技术开发了CMPT微泡浮选柱，利用专家系统控制浮选柱关键参数，确保浮选柱处于较好的工作状态。半工业试验和工业试验表明，微泡浮选柱能从浮选尾矿中回收微细粒级白钨。通过半工业试验获得了浮选柱的较优的工作参数，工业试验表明其平均精矿质量和回收率分别为：24．52％和43．41％，富集比35．03。水析试验表明5～10μm，10～19μm，19～38μm3个粒级的回收率均达到65％。

浮选技术的发展现状及展望

随着我国矿产资源特点日趋复杂、贫、细,浮选技术的发展对于选矿业的发展显得尤为重要。通过总结浮选技术的发展现状,论述了浮选工艺流程的更新,浮选新技术、高新柱分选设备和新浮选药剂的研发以及矿物分选新理念几个方面的内容,并对今后浮选技术的发展方向进行了展望。

组合捕收剂回收某钨矿的试验研究

采用由广州有色金属研究院自主研发的钨矿捕收剂GYB与ZL,对含WO30.81%的原矿,进行黑钨矿和白钨矿的混合浮选,发现GYB与ZL的组合存在正协同作用,并获得了含WO330.07%、回收率为88.79%的粗精矿。对粗精矿进行加温精选获得白钨精矿中WO3品位为68.24%,回收率为60.02%;精选尾矿经摇床选别获得黑钨精矿中WO3品位为66.17%,回收率为13.74%;次钨精矿中WO3品位为32.72%,回收率为10.79%;钨精矿中WO3总回收率为84.55%,获得了较好的选矿指标。

柱浮选优化充填的动力学分析

充填是提高浮选柱分选效率和降低浮选柱高度的有效途径之一.以筛板充填为基础,对旋流-静态微泡浮选柱浮选段进行充填方式优化,提出了筛板充填和蜂窝管充填的高效混合充填模式.基于气泡-矿粒碰撞概率理论分析了蜂窝管充填的优越性,并推导出气泡与矿粒碰撞概率的动力学方程.应用轴向扩散模型分析混合充填在保证回收率中的作用,导出了捕集区轴向无量纲扩散模型.混合充填使浮选柱下部保持矿浆高紊流的同时,上部浮选段形成"静态化"环境.

浮选柱技术的研究现状及发展趋势

简要论述了国内外浮选柱技术的研究现状及发展趋势,指出浮选柱技术是进行微细物料分选的先进技术,主要表现为:①柱分选技术成为研究重点;②柱分选设备的研制成绩显著;③柱分选工艺取得重大突破;④浮选柱自动控制迈上新台阶;⑤柱分选技术应用领域不断拓展。