浮选机运输区结构及动力学特征分析

浮选机内各动力学分区的流动特征复杂,运输区是其要动力学分区之一,主要起矿化气泡的输送作用,但相关的研究较少。选取单槽容积0.2m~3 KYF型充气机械搅拌式浮选机为研究对象,采用PIV测试技术在单相环境中分析了运输区的结构特征和动力学特征。研究表明运输区在浮选机中心纵截面内呈左右对称的结构,其一半的轮廓形状呈近梯形结构。运输区边界处的动力学特征存在较为明显的差异。本研究对通过调控浮选机运输区的结构特征改善粗粒矿物回收效果具有一定的指导意义。     

200m~3充气机械搅拌式浮选机动力学研究

对目前国内单槽容积最大的浮选机——200m~3充气机械搅拌式浮选机进行了动力学研究,主要测量和分析了浮选机在4种叶轮转速、6个充气量水平下的充气量、空气分散度、转速、功率、空气保有量,气泡直径等参数,结果表明,当主轴转速为109r/min,200m~3充气机械搅拌式浮选机动力学测试效果最佳,浮选机性能优良。     

充气机械搅拌式浮选机放大方法的研究

随着世界经济及国内经济的持续迅速增长,浮选机大型化已成为必然趋势,但浮选机放大方法依然以经验放大为主。本文从充气机械搅拌式浮选机的原理入手,从形状和动力学两个方面研究了充气搅拌式浮选机的放大方法,其中:槽体的放大因子为槽体截面积与叶轮直径的比值,放大规则为SD=a1Vb1;叶轮形状的放大因子为叶轮直径,放大规则为D=a2Vb2;叶轮搅拌强度的放大因子为叶轮搅拌雷诺数,其放大规则为J=a5Vb5;浮选机动力学的放大因子为S/D倍的叶轮线速度,其放大规则为S/DV=a6Vb6。该放大方法也可用于自吸气机械搅拌式浮选机,对大型浮选机放大理论的研究有一定的促进作用。     

200m~3大型机械搅拌式浮选机槽体及定子结构特征对动力学的影响

通过在机械搅拌式浮选机槽体上增加稳流板,改变定子通道面积、形状,寻求机械搅拌式浮选机的最优动力学参数。通过调整叶轮转速、浸没深度来比较稳流板及定子通道对浮选机动力学的影响。试验结果显示,增加稳流板和改变定子通道形状可明显改善槽内浮选环境。     

搅拌叶轮尺寸对双叶轮浮选机性能的影响

通过对常规机械搅拌式浮选机进行改造,将其搅拌系统设计为2个转子(离心叶轮和搅拌叶轮)配1个定子的结构模式,开发了双叶轮浮选机.为了考察搅拌叶轮直径对双叶轮浮选机性能的影响,试验设计了直径为32、34和36 m m的搅拌叶轮,考察了直径对充气性能、悬浮性能和分选性能的影响.试验表明:浮选机的充气、悬浮和分选性能,与搅拌叶轮的结构特征和浮选机的转速有关.随着转速的增加,充气量越来越大,固体颗粒悬浮质量分数越来越小,而分选效率先增大后减小;在实验室现有搅拌叶轮尺寸条件下,叶轮直径为36 mm时,充气、悬浮和分选效果都达到最佳状态.     

第六讲 浮选机的使用与维修

目前在工业上使用的浮选机种类很多,一般按其充气和搅拌矿浆的方式,可以分为两大类,即机械搅拌式和气升式。(1)机械搅拌式浮选机,矿浆的通气是由搅拌器的搅拌作用而使空气进入矿浆内并分散成微小气泡。(2)气升式浮选机矿浆的通气是完全靠直接吹入压缩空气来搅拌矿浆和产生气泡。随着矿山生产的发展,为了适应浮选各种     

200m~3超大型浮选机入选科技部重大成就展

十一五期间,挂靠北京矿冶研究总院的无污染有色金属提取及节能技术国家工程研究中心承担的十一五国家科技支撑计划课题德兴铜矿资源高效开发利用关键技术研究成功开发了200m3大型充气机械搅拌式浮选机。该课题以浮选动力学理论研究为基础,对超大型浮选机内矿物与气泡碰撞、粘附、脱落过程及影响上述过程的原因进行了深入研究,确定了超大型浮选机的设计原则,提出了我国独特的基于趋势外推和逐步回归法的超大型浮选机相似放大理论和关键技术。     

机械搅拌式浮选机相似转换原理

浮选过程复杂,影响参数繁多,使得浮选机设计一度停留在经验设计阶段,目前国内外均未形成通用的科学设计方法.根据机械搅拌式浮选机的工作原理、结构特点和工艺要求,运用相似理论,阐述了机械搅拌式浮选机相似转换原理,制定了适用于选煤用机械搅拌式浮选机模拟放大设计的几何相似、动力相似和运动相似准则,用于保持浮选机相似转换后,具有相似的搅拌强度、充气速率和颗粒悬浮条件,为浮选机的科学设计奠定了理论基础.以此设计的XJM-S系列浮选机获得了满意的生产效果.     

K-FV50NS充气式浮选机的应用

介绍了普浮乐浮选机的工作原理及结构特点,并对普浮乐浮选机与传统机械搅拌式浮选机在工艺效果及经济效益等方面进行比较,证实了普浮乐充气式浮选机可作为机械搅拌式浮选机的重要补充或成为其替代产品.     

320m~3充气机械搅拌式浮选机工业试验研究

320 m3充气机械搅拌式浮选机是我国目前单槽容积最大的浮选设备,本文介绍了大型浮选机的结构特点、动力学试验和工业试验情况,试验表明浮选机搅拌力强,槽内矿粒分布均匀,浮选机单台富集比铜达20.62,硫达71.44,功耗较国外同类型浮选机节省5.88%。该浮选机的成功研制标志着我国完全掌握了浮选设备大型化关键技术。     

Gas dispersion properties: bubble surface area flux and gas holdup

Bubble surface area flux has been related to flotation performance and advocated as a key “machine variable”. Analysis of available data suggests that bubble surface area flux (S_b) and gas holdup (ε_g) are related by S_b ∼ 5.5 ε_g. This was the case for flotation columns and mechanical cells, both laboratory and plant scale, over the approximate range S_b < 130s⁻¹ and ε_g < 25%. A relationship is expected given their similar dependence on gas rate and bubble size (both increase as gas rate increases and bubble size decreases). Reasons that a relationship may be obscured, especially in full size units because of the difficulty in defining the overall S_b and ε_g, are discussed. The possibility to replace S_b by ε_g as the machine variable has the advantage that gas holdup is easier to measure.     

新型双叶轮浮选机离心叶轮结构设计与优化

通过有机结合离心叶轮与搅拌叶轮,前期设计了2+1结构模式的双叶轮控制系统浮选机。为了进一步优化双叶轮浮选机搅拌系统,设计了不同结构离心叶轮,分别对使用不同离心叶轮时浮选机充气、水力空化和磷矿浮选分选性能进行了研究。试验表明：浮选机的充气、空化性能与离心叶轮的结构特征有关。大叶轮直径和套筒结构有利于增大浮选机的充气量。直叶片中空轴打孔结构有利于增大离心叶轮水力空化强度。通过细粒难选胶磷矿浮选试验,发现分选性能受离心叶轮结构特征影响较大,叶轮直径较大、直叶片、带套筒、中空轴上部打孔的离心叶轮获得的浮选分离效果较好。与常规机械搅拌自吸式浮选机相比,双叶轮控制系统浮选机具有较好的分选性能,在最优条件下,浮选精矿P2O5的品位、回收率、选矿效率分别可以提高1.44%、8.95%和5.12%。     

某铜矿粗扫选泡沫流动特性研究

某铜矿生产中粗、扫选均采用130m3浮选机,自建厂以来,生产指标一直较为稳定,但随着矿石性质的变化,指标有恶化趋势.从浮选泡沫粒级产率、粒级铜品位、粒级铜金属分布率和泡沫铜品位等泡沫流动特性方面对浮选指标的影响进行了分析,并在泡沫流动特性分析的基础上提出了提高铜回收指标的途径,为下一步浮选指标优化提供了技术参考依据.     

基于试验和数值分析的浮选机停留时间分布特性研究

浮选机停留时间分布研究对于认识大型浮选机内短路和死区等异常流动具有重要意义。本文采用示踪试验的方法研究了实验室和工业浮选机的停留时间分布特性。电导率示踪法可以有效应用于实验室浮选机的RTD研究,而荧光示踪法可以解决工业浮选机三相体系下的RTD研究。应用CFD方法研究了动态体系下浮选机的流态特征,揭示了示踪剂在浮选机内的流动过程,CFD方法揭示出浮选机内的停留时间分布特征与理想搅拌反应器相似,说明具有很好的搅拌混合效果。在世界最大的680m3浮选机开展了停留时间分布特征研究,平均停留时间达到理想平均停留时间的89%,说明浮选机内短路和死区等异常流动较少。     

Simultaneous determination of collection zone rate constant and froth zone recovery in a mechanical flotation environment

This paper presents the results of an investigation in which the new JKMRC Flotation Cell was used to determine the collection zone rate constant and froth zone recovery of a copper rougher ore simultaneously.The determination of these two parameters has been based on the straight line relationship that exists between the overall flotation rate constant and the froth depth [1].Experimental work was conducted using a copper rougher ore with a P₈₀ of 200 μm. Operating variables such as air flow rate, impeller speed, feed percent solids, collector and frother dose, and wash water flow rate were investigated. Analysis for copper and iron minerals (chalcopyrite and pyrite, respectively) was carried out.The results indicate that the collection zone rate constant of both copper and iron minerals increased with increasing air flow. Froth zone recovery, on the other hand, decreased as air flow was increased, possibly as a result of increased detachment of particles from bubbles in the froth. Increasing the impeller speed also increased collection zone rate constant and decreased the froth zone recovery of both minerals.Experiments at different wash water flow rates have showed that events occurring in the froth zone do not affect the kinetics of the pulp zone. Moreover, and interestingly, the froth recovery of attached particles (wash water reduced entrainment to a minimum) was non-selective. The froth recovery curves for chalcopyrite and pyrite followed each other very closely in every instance studied.The work has proved that it is possible to measure both the collection zone rate constant and froth zone recovery simultaneously and continuously in a mechanical flotation environment. The results obtained to date are interesting and the work is continuing.     

Improving flotation energy efficiency by optimizing cell hydrodynamics

Flotation is not a particularly energy intensive process. Therefore, flotation optimization has traditionally been focused on grade and recovery performance improvements. However, with the growing need for energy efficiency and the dramatic increase in flotation cell size in recent years it is worth considering how well energy is utilised within flotation cells. In conventional flotation cells a certain amount of energy is required to meet the basic requirements for flotation (air dispersion, solids suspension and particle-bubble collision). This paper investigates how that energy is dissipated in the flotation cell to determine the most efficient use of the imparted energy. The distribution of turbulence and its effect on flotation kinetics are investigated in a mechanical 3 m³ flotation cell for a range of hydrodynamic conditions. The effect of the different conditions are evaluated considering the Power Number (N_P); a dimensionless number that is a useful hydrodynamic indicator as it represents the ratio of energy added to the flotation cell dissipated as shear to that used to generate bulk flow. Results show that flotation rate in the collection zone and the fraction of the cell with higher turbulence increases as more of the power drawn by the impeller is dissipated as shear in the impeller-stator region (higher Power Number). This should promote higher collision rates and more efficient use of the energy imparted in the flotation cell.     

680m3充气机械搅拌式浮选机工业试验及应用

低品位矿石入选比例和选矿厂规模的日益增大,都对超大型浮选装备的处理能力、单机性能、智能化水平提出了更高的要求。680m_³超大型浮选机作为目前世界上容积最大的充气机械搅拌式浮选机,它的研制成功代表了我国浮选装备的研发能力及其智能化水平。研制过程中,针对超大型浮选机大型化的技术需求及应用特点,围绕浮选动力学、设备结构、智能控制三个方面,开发出了六项主要浮选装备创新技术,包括：浮选动力学调控技术、气泡矿化技术、流场控制技术、泡沫富集调控回收技术、智能优化控制技术和云平台数据存储与可视化操控技术。新研制的680m_³超大型浮选机被应用于铜尾矿再选工业应用中,形成了超大型浮选机尾矿再选的短流程浮选新工艺,实现了对尾矿中粗粒连生体矿物的有效回收,泡沫产品中+74μm矿物含量达30%以上,单机富集比8以上,并获得整个选厂综合回收率提升1.48个百分点的显著效果。     

FJC喷射式浮选机在城郊选煤厂的应用

 介绍了FJC型喷射式浮选机的结构、工作原理和技术特点;对FJC型喷射式浮选机与机械搅拌式浮选机的分选效果进行了比较;介绍了喷射式浮选机的优越性及使用过程中所总结出的几点经验;喷射式浮选机为全厂带来了很大的经济效益和环境效益。