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 derived by force analysis. Results obtained in this study provide a theoretical foundation for the design and scale-up of the FCSMC.     

矿物浮选过程的耗散结构分析

利用耗散结构理论分析了矿物浮选过程热力学和动力学特征．结果表明，进行浮选的矿浆体系是一个开放系统，矿浆处于湍流状态，系统的熵较大．随着浮选药剂和空气的不断输入，系统从环境吸入负熵流，悬浮矿粒与浮选药剂作用，使系统的熵降低，最后稳定在新的有序状态，形成耗散结构，有利于提高矿物回收率．以回收某镍尾矿为例，由于层流态的浮选柱有效泡沫层厚，底部的旋流力场赋予颗粒动能，能够容易地克服颗粒与气泡间的能垒，形成耗散结构．与浮选机相比，利用浮选柱回收的镍尾矿精矿品位提高0．29％，回收率提高3．02％．     

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 m³/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.     

胶磷矿柱式双反浮选工艺研究

针对我国西南地区难选硅-钙质胶磷矿,采用旋流-静态微泡浮选柱对其进行了柱式双反浮选工艺的研究.以硫酸和磷酸作为磷矿物抑制剂,脂肪酸类药剂PA-64作为碳酸盐矿物捕收剂,胺类药剂GE-601作为硅酸盐矿物捕收剂,考察了磨矿细度、药剂用量、循环泵工作压力等因素对浮选指标的影响.研究结果表明,采用旋流-静态微泡浮选柱双反浮选工艺,可以得到精矿P_2O_5品位30.49%,MgO含量0.73%,磷回收率81.03%的浮选指标,简化了胶磷矿浮选工艺流程.     

旋流-静态微泡浮选柱净化含油废水试验研究

为了提高含油废水处理效果、简化处理工艺,提出了以旋流一静态微泡浮选柱为核心的水处理工艺,在自行研制的试验装置系统上,研究了循环泵压力、柱体过流速度、混凝剂种类及投加量、表面活性剂投加量、油水pH值等主要工艺参数对模拟含油废水除油效果的影响.结果表明:以上因素均对脱油率有较大影响,在优化条件下,除油率可达95.7%,旋流-静态微泡浮选柱对含油废水有较高的净化能力.     

中低品位铝土矿浮选柱短流程分选研究

我国铝土矿绝大多数为中低铝硅比的一水硬铝石型,矿物嵌布粒度细,分选困难.在分析铝土矿矿石性质的基础上,利用旋流-静态微泡浮选柱对中低品位铝土矿进行分选,考察了捕收剂用量、循环压力、处理量等因素对浮选效果的影响.研究结果表明:铝土矿易泥化,微细粒级含量高,其有效分选是关键;随着捕收剂用量、循环泵压力、处理量的增大,氧化铝回收率增加、精矿铝硅比下降;当捕收剂用量1000g/t,循环泵压力0.17MPa,处理量4.0t/(m2.h)时,精矿铝硅比8.02～8.13,氧化铝回收率88.77%～90.01%.采用"一粗一精"两段浮选柱分选可以完成浮选机"一粗两精两扫"五段分选作业,分选流程短,工艺简洁.     

Experimental investigation and modeling of flotation column for treatment of oily wastewater

A unique cyclonic static microbubble flotation column was developed for oily wastewater separation. The separation efficiency was found to be highly dependent on gas holdup and bubble size distribution. By changing the circulation pressure, gas flow rate, frother concentration, the effect of operation parameters on gas holdup and oil removal efficiency were attained. A mathematical modeling between the kinetic constant and the gas holdup was established for oily water separation process. The results show that higher gas holdup and smaller microbubble sizes are beneficial to improve oil removal efficiency.     

FCMC—3000旋流微泡浮选柱计算机监控系统的研制

分析和阐述了FCMC－3000旋流微泡浮选柱监控系统的控制方法，硬件和软件系统，采用两点压力法，监测和控制浮选柱内液位，确立了加药量与入料流量的函数关系，编制的Windows3.X或Widows95/98应用软件实现了浮选柱的动态检测与控制，数据存贮与打印。     

A honeycomb-tube packing medium and its application to column flotation

We address problems in the development of large-scale flotation columns that use short cylinders. As a starting point, we investigated the packing medium to identify a highly efficient internal packing for the flotation column. The chosen packing was a honeycomb structure with an aperture diameter of 80 mm, a web thickness of 0.80 mm, a film height of 1000 mm, packed into a 400 mm diameter space, which completely filled the vessel at optimal cost. The column consisted of a modular ring of single-hole hexagonal honeycomb tube packing made from atactic polyproplene (PP-R). The packing was tested in a cyclonic, static mi-cro-bubble flotation column. Computational fluid dynamic modeling was used to analyze the flotation fluid in a honeycomb tube packed flotation column. Our results show that the fluid axial movement was maximized and that the transverse fluid velocities were zero in the vicinity of axial flow. Using the honeycomb tube packing for copper sulfide flotation we observed that the average concentration in the product was increased to 25.41%, from an average feed concentration of 0.729%, with an average recovery of 92.92%. The demands of on-site industrial production were met.     

浮选柱反浮选胶磷矿的影响因素

浮选柱是一种高效的细粒物料分选设备,但应用于胶磷矿浮选仍然受诸多因素制约.为考查浮选柱结构特征、工作参数和操作条件等因素对其分选效果的影响,采用试验室浮选柱对贵州瓮安磷矿进行了单一反浮选试验,重点研究了矿浆浓度、药剂用量、筛板充填方式和充气量对浮选柱反浮选效果的影响.结果表明,在磨矿细度为-0.074 mm占88％、矿浆浓度为25％（质量分数）、油酸钠用量为1.8 kg/t、硫酸用量为5 kg/t和充气量为400 L/h时,反浮选的分选效果较好.由于浮选柱可以通过充填筛板来改善其分选环境,因此在较优条件下,其分选效率比用浮选机时高1.57％.     

Process mineralogy of copper-nickel sulphide flotation by 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 micro-scope-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.     

紧凑型旋流气浮一体化技术的国产化研究进展与主体结构浅析

作为一种新型高效的油田采出水处理技术,紧凑型旋流气浮一体化技术近10年来在国外得到了商业化应用,国内虽然已经对该热点技术予以关注,但总体上尚处于产品放大试验阶段。笔者根据不设内筒式、内筒内旋式、内筒外旋式3大类,对国内业已公开的12家单位的结构方案进行系统介绍,针对旋流气浮一体化主体设备的内筒外旋流式气旋浮结构方案、微孔介质产生的微细气泡发泡方案、微细气泡与含油污水混合的罐外混合方案进行深入的理论或实验研究,以尽快推动该技术国产化和工业应用进程。     

Nanobubble generation and its applications in froth flotation (part Ⅲ): specially designed laboratory scale column flotation of phosphate

Froth flotation is used widely for upgrading raw phosphate. The flotation recovery of coarse phosphate (-1.18+0.425 mm) is much lower than that achieved on the -0.425+0.15 mm size fraction. Enhanced recovery of coarse phosphate particles is of great economic and environmental importance for phosphate industry. In this investigation, four different phosphate samples were aquired, characterized and tested in a specially designed laboratory-scale flotation column. Significant recovery improvement of coarse phosphate flotation was achieved using cavitation-generated nanobubble though its effects differ among the four testing phosphate samples. The laboratory-scale flotation column test results indicate that nanobubble increased P2O5 recovery by up to 10%-30% for a given Acid Insoluble (A.I.) rejection, depending on the characteristic of phosphate samples. The improvement ef-fect of nanobubble on the hard-to-float particles was more significant than that on easy-to-float particles, especially at lower col-lector dosages. Nanobubbles reduced the collector dosage by 1/3 to 1/2. Nanobubbles almost doubled the coarse phosphate flotation rate constant and increased the flotation selectivity index by up to 25%.     

反应条件对DEA吸收CO_2的影响研究

在自行设计的化学吸收-热解吸中试实验系统上,以DEA(二乙醇胺)水溶液为吸收液,CO2为处理对象,分别考察了吸收液体积分数、液气体积比、CO2体积分数和空塔气速对CO2脱除效率的影响,并计算了吸收液CO2摩尔负荷、总传质系数和填料层单位压降的变化。实验结果表明,液相传质阻力即吸收液浓度和液气体积比增加对CO2脱除起促进作用效果,最佳操作条件为DEA吸收液体积分数10%～20%、液气体积比为0.125;而气相传质阻力即CO2体积分数和空塔气速增加对吸收效果有负影响。此外,气相条件对CO2脱除效果的影响远比液相条件小得多,说明传质阻力主要在液相侧。     

射流浮选柱气泡发生器及其充气性能的研究

根据射流泵原理设计了一种浮选柱气泡发生器，并对其充气性能进行了试验，研究了气泡发生器结果参数、流体压力、负压与柱内含气率的关系；探讨了浮选过程中浮选药剂浓度、矿浆浓度变化对含气率的影响．结果表明：气泡发生器的射流面积比对含气率有较大影响，最佳面积比为6～10；含气率随压力增高而增加，压力升到一定程度后，含气率趋于平稳；当气泡发生器吸气室负压达到一定数值后，含气率也将趋于饱和；随起泡剂用量加大，含气率呈上升趋势；随矿浆浓度的增加，含气率则呈下降趋势．研究结果为射流浮选柱气泡发生器的设计和结构优化提供了依据。     

苯-甲苯双效精馏的优化计算

建立了苯－ 甲苯单塔精馏的ＭＥＳＨ 方程组,采用分割技术用计算机进行迭代求解,得到了塔内各理论板的气液流量、温度和浓度分布及塔顶和塔底热负荷,并计算了该过程的热力学效率为１３ ．９７ ％ 。在此基础上,提出了苯－ 甲苯的并流型双效精馏流程,并对该流程进行了工艺分析,确定了高压塔塔顶采出量及回流比为两个塔的协调变量。在规定各塔压和高压塔塔底流量的条件下,以综合效益为优化目标,以两塔的回流比为决策变量,采用一维定步长搜索给出决策变量改进值的方法进行优化计算,确定了双效精馏流程的工艺操作条件。优化计算结果表明,高压塔压力为３４ ．３４ Ｎ／ｃｍ ２ ,回流比为１ ．１ ,低压塔压力为常压,回流比为３ ．２ 的双效精馏比单塔精馏可节约供热量３２ ％ ,节约蒸汽用量２８ ％ ,且双效精馏过程的热力学效率可提高４ ．３９ ％ ,是一种非常有效的节能措施     

Recovery and grade prediction of pilot plant flotation column concentrate by a hybrid neural genetic algorithm

Today flotation column has become an acceptable means of froth flotation for a fairly broad range of applications, in particular the cleaning of sulfides. Even after having been used for several years in mineral processing plants, the full potential of the flotation column process is still not fully exploited. There is no prediction of process performance for the complete use of available control capabilities. The on-line estimation of grade usually requires a significant amount of work in maintenance and calibration of on-stream analyzers, in order to maintain good accuracy and high availability. These difficulties and the high cost of investment and maintenance of these devices have encouraged the approach of prediction of metal grade and recovery. In this paper, a new approach has been proposed for metallurgical performance prediction in flotation columns using Artificial Neural Network (ANN). Despite of the wide range of applications and flexibility of NNs, there is still no general framework or procedure through which the appropriate network for a specific task can be designed. Design and structural optimization of NNs is still strongly dependent upon the designer’s experience. To mitigate this problem, a new method for the auto-design of NNs was used, based on Genetic Algorithm (GA). The new proposed method was evaluated by a case study in pilot plant flotation column at Sarcheshmeh copper plant. The chemical reagents dosage, froth height, air, wash water flow rates, gas holdup, Cu grade in the rougher feed, flotation column feed, column tail and final concentrate streams were used to the simulation by GANN. In this work, multi-layer NNs with Back Propagation (BP) algorithm with 8-17-10-2 and 8-13-6-2 arrangements have been applied to predict the Cu and Mo grades and recoveries, respectively. The correlation coefficient (R) values for the testing sets for Cu and Mo grades were 0.93, 0.94 and for their recoveries were 0.93, 0.92, respectively. The results discussed in this paper indicate that the proposed model can be used to predict the Cu and Mo grades and recoveries with a reasonable error.     

化学工程方法在浮选机放大中的应用

以磷块岩为例,阐述浮选过程中的化学工程问题,依据动量传递、质量传递和化工动力学的有关概念提出用两区综合模型描述浮选机,以传质系数表征浮选动力学常数并以传质系数相等为比拟放大准则。借用whitman,w.G.,的膜理论与矿物双电层理论相结合,将浮选动力学建立在多相扩散传质基础上,为浮选动力学的应用及浮选机(柱)的开发探索了一种新方法。     

Treatment of Wastewater Containing Heavy Metals Using Dissolved Air Released Flotation Column

A new type of dissolved air released flotation column is developed to treat wastewater containing Cr（Ⅵ） based on advantages of both dissolved air floatation and column floatation. By using a column with a diameter of 50 mm and a specially made dissolved air releaser, micro-bubbles inside the column can be formed. N2H4H2O was used as reductant, AlCl3 as flocculant, C12H25SO3Na（SDS） as surfactant in the experiment. The effects of pH of wastewater, pressure of dissolved air, ratio of return water, and concentration of flocculant and surfactant on the removal efficiency are studied. The results show that the efficiency of dissolved air released flotation column is much higher than that of other approaches after the operation parameters are optimized, with the reduction ratio of Cr（Ⅵ ） in wastewater reaching 98%. So this technique can be widely used in wastewater treatment     

新型柱浮选泡沫输送装置及固液两相流动特性

针对高含气率、高黏性柱浮选泡沫输送的需要,设计了一种新型柱浮选泡沫输送装置,并进行了固液两相流动特性模拟.结果表明,漩涡多靠近叶片工作面,其方向与叶轮旋转方向相反;叶轮内各流道压力分布较为均匀,叶轮中心区域为低压力区;颗粒直径越大,叶片工作面和轮缘处分布的颗粒越多,磨损程度越重;颗粒浓度越大,流体的全速度越高,叶轮出口附近处颗粒速度梯度越大,叶轮受局部磨损程度越重.基于数值模拟的优化设计结果表明,采用后倾叶片、扩大出料管径和增加出料管数量,有利于改善输送效果.