Process mineralogy of copper-nickel sulphide flotation by a cyclonic-static micro-bubble flotation column

In our study we investigated a refractory copper-nickel sulfide ore separation by using a cyclonic-static micro-bubble flotation column (FCSMC). The process mineralogy of the main products was studied. Using a scanning electron microscope-energy dispersive system (SEM-EDS) and an X-ray spectrometer the mineral category and content of samples were analyzed. By using a mineral liberation analyzer (MLA) the mineral liberation characteristics were revealed. It is shown that in roughing feed the monomers liberation degree of nickel pyrite and chalcopyrite take up 84.11% and 88.82%, respectively. In tailings, the lost nickel pyrite and chalcopyrite are mainly monomers. Therefore, strengthening the micro-fine particle recovery capacity is the key to increase recovery.

Experimental study on flow control of the turbulent boundary layer with micro-bubbles

The effect of micro-bubbles on the turbulent boundary layer in the channel flow with Reynolds numbers (Re) ranging from 0.87 × 105 to 1.23 × 105 is experimentally studied by using particle image velocimetry (PIV) measurements.The microbubbles are produced by water electrolysis.The velocity profiles,Reynolds stress and instantaneous structures of the boundary layer,with and without micro-bubbles,are measured and analyzed.The presence of micro-bubbles changes the streamwise mean velocity of the fluid and increases the wall shear stress.The results show that micro-bubbles have two effects,buoyancy and extrusion,which dominate the flow behavior of the mixed fluid in the turbulent boundary layer.The buoyancy effect leads to upward motion that drives the fluid motion in the same direction and,therefore,enhances the turbulence intense of the boundary layer.While for the extrusion effect,the presence of accumulated micro-bubbles pushes the flow structures in the turbulent boundary layer away from the near-wall region.The interaction between these two effects causes the vorticity structures and turbulence activity to be in the region far away from the wall.The buoyancy effect is dominant when the Re is relatively small,while the extrusion effect plays a more important role when Re rises.

Micro-bubble Drag Reduction on a High Speed Vessel Model

Ship hull form of the underwater area strongly influences the resistance of the ship. The major factor in ship resistance is skin friction resistance. Bulbous bows, polymer paint, water repellent paint （highly water-repellent wall）, air injection, and specific roughness have been used by researchers as an attempt to obtain the resistance reduction and operation efficiency of ships. Micro-bubble injection is a promising technique for lowering frictional resistance. The injected air bubbles are supposed to somehow modify the energy inside the turbulent boundary layer and thereby lower the skin friction. The purpose of this study was to identify the effect of injected micro bubbles on a navy fast patrol boat （FPB） 57 m type model with the following main dimensions： L=2 450 ram, B=400 mm, and T=190 mm. The influence of the location of micro bubble injection and bubble velocity was also investigated. The ship model was pulled by an electric motor whose speed could be varied and adjusted. The ship model resistance was precisely measured by a load cell transducer. Comparison of ship resistance with and without micro-bubble injection was shown on a graph as a function of the drag coefficient and Froude number. It was shown that micro bubble injection behind the mid-ship is the best location to achieve the most effective drag reduction, and the drag reduction caused by the micro-bubbles can reach 6%-9%.

Velocity distribution of the flow field in the cyclonic zone of cyclone-static micro-bubble flotation column

Laboratory experiments have been conducted to study the flow field in a cyclone static micro-bubble flotation column. The method of Particle Image Velocimetry (PIV) was used. The flow field velocity distribution in both cross section and longitudinal section within cyclonic zone was studied for different circulating volumes. The cross sectional vortex was also analyzed. The results show that in cross section as the circulating volume increases from 0.187 to 0.350 m 3 /h, the flow velocity ranges from 0 to 0.68 m/s. The flow field is mainly a non-vortex potential flow that forms a free vortex without outside energy input. In the cyclonic region the vortex deviates from the center of the flotation column because a single tangential opening introduces circulating fluid into the column. The tangential component of the velocity plays a defining role in the cross section. In the longitudinal section the velocity ranges from 0 to 0.08 m/s. The flow velocity increases as does the circulating volume. Advantageous mineral separation conditions arise from the combined effects of cyclonic flow in cross and longitudinal section.

Optimization of rheological parameter for micro-bubble drilling fluids by multiple regression experimental design

In order to optimize plastic viscosity of 18 mPa·s circulating micro-bubble drilling fluid formula,orthogonal and uniform experimental design methods were applied,and the plastic viscosities of 36 and 24 groups of agent were tested,respectively.It is found that these two experimental design methods show drawbacks,that is,the amount of agent is difficult to determine,and the results are not fully optimized.Therefore,multiple regression experimental method was used to design experimental formula.By randomly selecting arbitrary agent with the amount within the recommended range,17 groups of drilling fluid formula were designed,and the plastic viscosity of each experiment formula was measured.Set plastic viscosity as the objective function,through multiple regressions,then quadratic regression model is obtained,whose correlation coefficient meets the requirement.Set target values of plastic viscosity to be 18,20 and 22 mPa·s,respectively,with the trial method,5 drilling fluid formulas are obtained with accuracy of 0.000 3,0.000 1 and 0.000 3.Arbitrarily select target value of each of the two groups under the formula for experimental verification of drilling fluid,then the measurement errors between theoretical and tested plastic viscosity are less than 5%,confirming that regression model can be applied to optimizing the circulating of plastic-foam drilling fluid viscosity.In accordance with the precision of different formulations of drilling fluid for other constraints,the methods result in the optimization of the circulating micro-bubble drilling fluid parameters.

Application of Air Floatation in Water Quality Maintenance of Ecolandscape Pool in Zhongxing Mangrove Bay

The invasion of various pollutant sources and lack of water circulation may easily lead to the eutrophication and deteriorated water quality of the landscape water system.This study focuses on the application of air floatation method in water quality maintenance with the eco-landscape pool of Zhongxing Mangrove Bay as the study object,so as to provide a scheme for maintaining the water quality of artificial lakes.

Research on Performance of a Rectangular Floatation Cushion with High Stiffness for a Pneumato-static Slideway

In this paper, a high stiffness rectangular floatation cushion with a variable-section pressure equalizing groove of an elastic membrane for a pneumato-static slideway is presented and designed in order to increase stiffness of the floatation cushion. Gas film pressure distribution and carrying capacity of the floatation cushion are studied through theoretical analysis and by using the overlapping stitching technique. The carrying capacity and stiffness were obtained by using the coupling procedure of the gas lubrication governing equation and elastic deformation of the membrane governing equation. The results of theoretical calculations can obtain a conclusion that the effect of the gas pressure makes the annular elastic membrane elastically deform that brings about changes of throttling area and pressure groove depth of the floatation cushion. It makes carrying capacity and stiffness of the new style floata- tion cushion markedly improve over the conventional flotation cushion. The new floatation cushion has a wider ap- plication and popularization of space. Key words： floatation cushion; variable-section pressure equalizing groove;stiffness

Indirect Determination of CTMAB with Sodium Chloride and Ammonium Thiocyanate by Floatation and Separation of Zinc

A new method for indirect determination of cetyl-trimethyl ammonium bromide (CTMAB) with NaCl and NH4SCN by floatation and separation of zinc has been studied. The study shows that Zn(II) can associate with NH4SCN and CTMAB to form insoluble ternary ion-association complex, and the precipitate can float on the surface of the liquid phase. A good linear relationship is observed between the floatation yield (E%) of Zn(II) and the amount of CTMAB. On the ground, CTMAB can be indirectly determined by determining E% of Zn(II). The results were satisfactory.

AQUEOUS TWO-PHASE GAS FLOATATION SPECTROPHOTOMETRIC DETERMINATION OF TRACE TETRACYCLINE IN ENVIRONMENTAL WATER SAMPLE

A green method for separating and enriching trace tetracycline （TC） in environment water by Aqueous Two-phase Gas Floatation Spectrophotometry has been proposed, the principium was discussed. In this paper, the hydrophobic complex composed of Mg（II） and TC was floated into organic phase under the optimal conditions： pH=10, the floatation equipment is home-made, n-propyl alcohol as the organic solvent, sodium chloride as the separating phase reagent. The data were obtained by spectrophotometry after floatation; The linear regression equation is A=2.33×10^5C（mol/L）＋0.2179, linear range is from 3.77×10^-7mol/L to 6.32×10^-5 mol/L, respectively, with thecorrelation coefficient （r） better than 0.9997, relative recoveries is 99.7% to 100.3%, limit of detection was 4.29×10^-5mol/L, The method can be applied to analyse the trace TC in water sample, the result is better.

卧式紧凑型旋流气浮装置旋流筒结构优化数值模拟研究

由于油田开发采出液含水率上升和海上平台空间的限制,亟需紧凑型污水处理设备用于对海上油田含油污水处理。对此设计了卧式紧凑型旋流气浮装置,通过Fluent数值模拟方法对该装置旋流筒区域的流场分布及油水分离性能开展了系统研究,探究了旋流筒结构、入口管径、含油污水入口速度和入口含油率等因素对油水分离效果的影响。结果表明,在入口管径为20 mm,含油污水入口速度为2 m/s时,采用导流叶片的旋流筒结构能获得较好的流场分布;含油污水入口速度越大切向速度衰减越严重;旋流筒在高度为100~300 mm时切向速度衰减较大,在高度为300~650 mm内衰减较小;相同含油污水入口速度下,增大入口管径能使旋流筒内油相体积分数增大;增大含油污水入口速度反而会导致旋流筒内油相体积分数减小;旋流筒内油相体积分数呈“U”型分布,且随入口含油率增大而增大,与入口含油率成正比。

基于气泡雾化喷嘴的低能耗含油污水处理实验研究

微气泡气浮技术在低能耗下对含油污水的高效处理是目前的研究热点。利用气泡雾化喷嘴作为微气泡发生器,搭建了低能耗微气泡射流气浮处理含油污水的实验系统,系统研究了气液质量流量比(ALR)和工作压力(p)对微气泡群尺度分布特征和除油效果的影响,并计算了气泡雾化喷嘴的能耗。实验结果表明,利用气泡雾化喷嘴形成液下射流可以产生大量微气泡,其中尺度小于150μm的气泡数量占比在55%以上、小于600μm的气泡数量占比在98%以上;随着ALR的增加,微气泡数量整体呈现先增后减的变化趋势,最佳ALR=0.15;当p=0.2 MPa、ALR=0.15时,微气泡群的索特尔平均直径可降低至238μm,出水含油质量浓度为29.73 mg/L,微气泡射流气浮装置处理1 kg含油污水时能耗仅为6.53×10^(-4) kW·h,较溶气气浮能耗降低35%以上。

红外照相机的热浮法湍射流流态转捩机理探究

为了探究湍射流3种流动状态的转捩机理,设计并搭建了可控式湍射流实验仪,利用热浮法红外拍摄了3种流态,实现了湍射流的可视化及精确测量。通过实验观察和分析了包络态中流体转捩速度与雷诺数的关系,确定了转捩临界雷诺数大小范围,并推导和验证了涡环态中推进力与流体流速的半经验公式;同时通过颜色仿真展示了喷口截面处的压强分布图像;利用网格剖分的方式分析了涡环转捩机理,完善了流体运动过程的精细测量,为实验室测量雷诺数提供了一种可行方法。

碳酸盐型胶磷矿浮选抑制剂种类机理研究进展

磷矿位于四种非金属战略性矿产资源之首,战略意义重大。但我国磷矿资源禀赋差、可选性难度大,高效回收属行业难题。浮选法是回收磷矿资源最常用的方法,因此,本文以浮选理论为基础,重点综述碳酸盐型胶磷矿正浮选抑制剂分子结构及其与矿物的作用机理、影响浮选性能等内容,并结合药剂的性质、成本、环保等因素预测胶磷矿正浮选抑制剂未来的研究及发展方向。

内蒙古某硫化铜矿石浮选工艺矿物学研究

为了查明矿石性质对选矿指标的影响,对内蒙古某铜矿石采用BPMA工艺矿物学自动测量仪、化学多元素分析、物相分析、扫描电子显微镜-能谱分析等,研究了矿石的矿物组成、嵌布特征、粒度分布、赋存状态等工艺矿物学特征。研究表明,原矿中铜主要以硫化铜形式存在,主要铜矿物是黄铜矿,主要分布在0.038mm以下粒级范围内,累计含量为90.10%,单体解离度为71.59%,未解离颗粒中黄铜矿主要与脉石矿物边缘或被包裹镶嵌连生。影响选矿指标的工艺矿物学因素主要有粒度分布、嵌布特征和铁矿物的影响。基于工艺矿物学研究分析,原矿铜矿物粒度分布较细,与脉石矿物紧密连生,在原工艺流程的基础上,主要提出铜粗精矿再磨新工艺,试验在磨矿细度-0.074mm含量占75%的条件下,采用“一次粗选、三次精选、两次扫选、粗精矿再磨”的工艺流程。在原矿含铜1.04%的条件下,可以获得含铜24.25%、回收率95.24%的铜精矿。通过工艺矿物学进行产品检查,可知铜精矿中石英、闪石等矿物主要与铜矿物边缘连生或被包裹镶嵌在铜矿物间隙,影响铜精矿品位。损失在尾矿中的黄铜矿主要以微细粒单体及贫连生体形式存在,且这部分贫连生体的铜矿物主要呈不规则状、斑点状、星点状等嵌布在脉石矿物间隙。

沉淀-气浮-深度处理联用工艺排泥水处理系统设计

吉林省某水厂工程近期设计规模为2.5×10^(5)m^(3)/d,远期设计规模为5×10^(5)m^(3)/d。采用沉淀-气浮-深度处理联用净水工艺,根据原水水质灵活组合。文章介绍了多运行模式排泥水系统设计,主要包括集泥池、排渣池、排水池、回流水池、浮动槽排泥池、浓缩池、上清液收集池、平衡池、脱水机房及废水调节池。该系统具有运行灵活、水资源利用率高、药剂运行成本低、回流冲击负荷小的优点。砂滤池反冲洗排水静沉后上清液回用,底泥排至排泥池处理。炭吸附池反冲洗排水回用方式根据水质确定。设计废水调节池及废水排出管道,解决了厂外部无市政污水管道的问题。排泥水处理系统工程费为7900万元。

波浪环境下带助浮装置航行体落水冲击流场及运动特性研究

为探究波浪环境下带助浮装置航行体下落冲击过程中的流场以及运动演化特性,基于CFD(computational fluid dynamics)数值模拟技术,在方法上耦合了VOF(volume of fluid)多相流模型、k-ωSST湍流模型、Schnerr-Sauer空化模型以及Stokes五阶非线性波理论,建立了一套针对入水冲击问题的数值计算方法,并采用速度边界法进行造波。经验证,试验与数值结果在下落位移上对比差异较小,该数值方法可靠有效,且造波结果与Stokes五阶非线性波理论吻合较好。然后,基于构建的数值方法,在不同波浪环境下对带助浮装置航行体下落入水冲击过程进行了数值模拟,计算带助浮装置航行体冲击过程的位移、速度、加速度以及助浮装置受力情况,分析冲击过程中航行体的运动学参数、动力学参数以及入水空泡流场演化过程,总结了波浪环境下带助浮装置航行体的入水冲击特性。结果表明,波浪环境对下落冲击过程的影响主要体现在运动衰减段,水平方向的冲击相较于垂直方向的冲击受到波浪环境的影响要大得多,不同海况对航行体的水平冲击造成的影响主要是通过影响入水空泡的形成与溃灭过程实现的。

超低灰无烟煤选择性絮凝浮选试验研究

以宁煤集团某选煤厂的重选精煤为研究对象,对磨矿至小于45μm的细粒煤样进行浮选试验;在矿浆浓度为60 g/L时,以柴油作为捕收剂,仲辛醇作为起泡剂,聚丙烯酰胺作为絮凝剂,研究了捕收剂、起泡剂和絮凝剂用量对浮选指标的影响,同时分析了非离子型、阳离子型和阴离子型聚丙烯酰胺的选择性絮凝作用。结果表明,浮选精煤灰分随着捕收剂柴油用量的增加而增加,精煤产率和浮选完善指标出现相同的趋势,在柴油用量为3000 g/t时,精煤产率达到最大93.10%,浮选完善指标也达到最大46.82%,此后精煤产率和浮选完善指标逐渐下降。随着起泡剂仲辛醇用量的增加,浮选精煤灰分先稳定在1.43%,产率呈缓慢降低的趋势,在仲辛醇用量为200 g/t时,精煤灰分和产率同时达到最低,分别为1.35%和88.77%,此时的浮选完善指标最大,为47.29%,此后精煤产率和灰分逐渐增加,浮选完善指标呈现下降的趋势。相比于非离子和阳离子型聚丙烯酰胺,阴离子型聚丙烯酰胺PAM的浮选效果更好。当PAM用量为90 g/t,捕收剂用量为3000 g/t,起泡剂用量为200 g/t时,浮选精煤灰分为1.24%,回收率为88.75%,浮选完善指标为50.93%。

某堆存铜渣中回收铜金属的选矿试验研究及生产应用

对某堆存铜渣开展了工艺矿物学及选矿试验研究,并确定了回收其中铜金属的选矿工艺流程及参数。在原矿含铜0.81%条件下,以Z-200为捕收剂、2#油为起泡剂,磨矿细度为-0.038 mm粒级占85%,采用快速浮选产出高品位铜精矿,再经一粗两扫两精优先浮选得到低品位铜精矿产品,可获得铜品位26.40%的高品位精矿和铜品位3.58%的低品位精矿,总铜精矿铜品位13.03%、铜回收率76.47%。该回收工艺已成功应用于工程化生产实践,实现了堆存铜渣中铜金属的回收利用。

污水厂“准Ⅲ类”排放标准提标改造设计探讨

针对昆明市出台的《DB 5301/T 43—2020城镇污水处理厂主要水污染物排放限值》要求,滇池南岸某污水处理厂需要提标改造至昆明A限值排放。综合分析了污水厂现有工艺和运行情况,得出提标改造的重点及难点是TN和TP的去除,需要对现状生化系统挖潜改造和新增深度脱氮、超级限除磷工序实现提标改造目标。根据污染物去除机理和相关工程实例分析,生化系统挖潜改造采用多点进水、加大回流比、缺氧区加碳源、多点化学除磷、控制溶解氧等措施,深度脱氮单元采用上向流反硝化生物滤池工艺,超级限除磷单元采用溶气气浮+过滤工艺;并介绍了各单元设计参数,将各工艺段有机结合,使整个系统稳定运行,最终出水达标排放。

刺梨饮料加工废水处理工艺论证

以六枝特区某刺梨饮料加工企业产生的废水为例,根据废水浓度及下游污水处理厂接纳浓度要求,论证“气浮+水解酸化+AO”工艺是否可以满足污染物削减要求。采用完整的工艺流程为“格栅+沉砂+调节+中和、气浮+水解酸化+AO+竖流式二沉池”,由于刺梨饮料废水的具有周期性,生产周期为每年的8-10月,此时正值当地气温最高,反硝化速率最快之时,在此条件下该工艺流程能够有效去除废水中的COD_(Cr)、氨氮、总氮、悬浮物等污染物,系统运行稳定可靠、抗冲击负荷能力强、占地面积小;如其他水质一样的废水,但其产生周期在温度较低时段,受制于反硝化速率的影响,采用工艺需重新论证。