高选择性浮选机设计原理及分选效果

通过置于浮选分离区域的振荡分离器作用于周围介质产生谐脉冲运动,被夹带的亲水性矿粒获得足够能量游离为自由颗粒落回矿浆,从而减轻夹带污染.根据振荡浮选原理和相似理论,成功设计了FJG-S8型高选择性浮选机,在相同浮选尾煤灰分下,浮精灰分降低了1.42%,浮选完善指标提高了4.14%,为高灰难浮细粒煤提供了有效分选设备.     

浮选中振荡分离理论与实践

置于浮选槽分离区振荡分离器的机械振动 ,激励其周围介质振荡 ,当两个波动源之间最小局部振幅大于能够产生机械夹带的气泡表面间最大距离时 ,被气泡夹带的亲水性矿粒游离为自由矿粒 ,落回矿浆 ,从而减轻夹带污染。通过实验室试验 ,研究了振荡分离器的基本结构和参数。工业性生产实践表明 ,该法可有效降低浮精灰分 1 %～ 2 % ,提高浮选完善指标 3 %以上 ,突破了以往用冲洗水降灰的传统方法 ,为降低浮精灰分提供了新的途径。     

浮洗中振荡分离理论与实践

置于浮选槽分离区振荡分离器的机械振动，激励其周围介质振荡，当两个波动源之间最小局部振幅大于能够产生机械夹带的气泡表面间最大距离时，被气泡夹带的亲水性矿粒游离为自由矿粒，落回矿浆，从而减轻夹带污染。通过实验室试验，研究了振荡分离器的基本结构和参数。工业性生产实践表明，该法可有效降低浮精灰分１％￣２％，提高浮选完善指标３％以上，突破了以往用冲洗水降灰的传统方法，为降低浮精灰分提供了新的途径。     

气泡—矿粒脱附力与矿物浮选关系的研究

采用离心技术对方铅矿、石英的单矿物和混合矿的矿粒与气-黄药溶液界面的粘附强度进行了测定。对混合矿颗粒脱附和下沉时昕需的临界离心力与Nutt和Scheludko单个球粒模型的理论值进行了比较,研究了矿粒大小、初始捕收剂相分散剂浓度对粘附力和浮选效率的影响,并发现矿粒在气-液界面的粘附强度与浮选效率有密切关系。方铅矿-石英人工混合矿的脱附力测量和浮选试验的结果表明:方铅矿与石英矿粒的粒径比对方铅矿的脱附力和浮选选择性有重要影响,并发现力铅矿-石英体系的浮选选择性与混台矿中方铅矿颗粒在气-液界面的粘附强度有密切关系。     

用聚合物抑制剂减少黄铜矿浮选中夹带的细粒石英数量

亲水性脉石矿物的严重机械夹带会对微细矿粒浮选分离产生负面影响,而且目前没有有效可行的方法来消除细粒脉石夹带的影响.本研究探索了一种新的方法:即使用高分子聚合物抑制剂减少在黄铜矿浮选中细粒石英的夹带量.其原理是,使用具有絮凝作用的聚合物抑制剂,不仅可以使需要被抑制的矿物具有亲水性,而且还可以增大它们的颗粒尺寸,因而就能减少浮选气泡夹带和机械夹带.试验发现,某些聚合物在不影响黄铜矿浮选的情况下,能抑制和絮凝细粒石英.使用聚合物时的分选效果比不使用时有显著的改善.     

浮选矿浆紊流强度对矿物浮选的影响

从矿粒与气泡的碰撞、粘附和脱附过程，分析研究了包头白去鄂博磁铁精矿反浮选脱除萤石精选试验中紊流强度对浮选的影响。结果表明、降低矿浆紊流强度对浮选有利。     

细粒矿物絮团浮选的理论和应用

絮团浮选是一种分选细粒有用矿物的有效方法.这个方法的基础是,首先分散细矿粒,然后通过添加特效吸附的捕收剂使矿粒表面疏水,再在强裂剪切搅拌矿浆时,使有用矿粒选择性絮凝.添加少量非极性油来强化絮凝过程.本文首先简单叙述了絮团浮选法,再根据试验结果讨论了影响絮团浮选过程的参数,最后介绍了几个应用絮团浮选法分选细粒金银矿物、细粒硫化矿和细粒煤的实例.     

絮凝浮选氧化铅锌矿的理论与实践

研究了絮凝浮选分选细粒有用矿物的理论,包括分散细矿粒、加入有效絮凝剂、使氧化锌矿泥的粒度增大、可浮性增强;添加特效吸附捕收剂使矿粒表面疏水,强烈搅拌矿浆使有用矿粒选择性絮凝。根据试验结果讨论了影响絮凝浮选过程的参数,介绍了应用絮凝浮选分选细粒氧化铅锌矿的实践。     

DTAB 对石英-气泡间相互作用力的影响研究

为了研究(十二烷基三甲基溴化铵)DTAB 对石英-气泡间相互作用的 影响,采用黏附/脱附测试系统、接 触角测量仪和表面张力仪对 DTAB 体系下亲水性石英玻璃基板与气泡间相 互作用力、表面接触角以及溶液表面张力 进行了测量。 结果表明:在 DTAB 体系中,石英玻璃基板与气泡间的黏附力 /脱附力随着 DTAB 浓度的增加先增加后 减小,在 DTAB 浓度为 1 mmol/L 时,脱附力达到最大,为 129. 9 μN; 石英玻璃基板表面接触角也呈现类似的变化规 律,在 DTAB 浓度为 4 mmol/L 时,接触角达到最大,为 51. 8°,较石英 玻璃基板与气泡间黏附力/脱附力而言,接触角的 变化具有一定的滞后性。 这是由于黏附力/脱附力受石英玻璃基板表面 接触角和表面张力协同支配,在 DTAB 存在体 系下,当接触角达到最大时,溶液表面张力已下降至 35. 95 mN/m,导致 石英玻璃基板与气泡间黏附力/脱附力提前出 现下降趋势。 进一步用浮选动力学试验加以验证,浮选结果表明,当浮选体 系中加入 1 mmol/L DTAB 时可以获得精 矿产率为 97. 10%的指标。 浮选结果与黏附力/脱附力曲线得到的结果 保持一致。     

浮选精矿在进入磁选前的分散

浮选精矿高梯度磁选和湿式强磁场磁选的实验室试验证明，磁选的品位和回收率在很大程度上受到原给矿矿粒分散状态的影响。在本次研究中，以用脂肪酸捕收剂浮选后的锂辉石浮选精矿为例，当为改善矿粒的分散状况，把矿浆的ｐＨ值从７调节到２时，其回收率提高了１０％。对于用膦浮选后含有闪锌矿和黄铜矿的铅精矿产品，其品位和回收率在ｐＨ值为５左右时均为最佳，回收率提高约５％。     

粗细粒级差异化给矿对浮选柱选别性能的影响

粗细粒级矿物具有不同的浮选特性,浮选柱主要应用于精选作业的细粒级矿物分选,对粗颗粒矿物回收率较低,限制了浮选柱的应用。在泡沫层分选理论的基础上,以纯石英矿物(纯度大于99%)为代表矿样,将其分成150~280μm和-15μm粗细粒级两个组分,采用Ф100 mm×2 000 mm浮选柱开展试验考察粗细粒级差异化给矿对选别性能的影响。在一个试验中将粗细粒级矿物混合给入浮选柱泡沫层之下进行常规浮选,在另一个试验中将粗细粒级矿物差异化给入浮选柱泡沫层之上和泡沫层以下分别进行泡沫层分选和常规浮选。试验对比结果表明,粗细粒级差异化给矿提高了浮选柱精矿回收率,对粗颗粒矿物回收效果提升更为显著。     

Froth recovery measurements in an industrial flotation cell

The froth phase serves an important role in upgrading the final concentrate in flotation. At present, the techniques that are used in the mineral industry to determine the effect of froth phase on the metallurgical performance of plant scale flotation cells have limitations.The aim of this paper is to investigate the performance of the froth in an industrial flotation cell. A unique device has been developed which is able to decouple the froth zone from the pulp zone. The device consists of two concentric tubes. The inner tube acts as a dropback collection chamber or catcher. The particles that return from the froth phase fall directly into the catcher and are collected as froth dropback. This technique is capable of measuring plant scale flotation cell froth recovery as well as providing valuable information on froth dropback particles.The froth recovery measurements were carried out in a rougher bank of a copper concentrator treating sulphide minerals. The dropback device is designed so that it can be immersed into an industrial size flotation cell and plant froth recovery measurements can be taken at any given location. During the experiments, the bubbles laden with valuable mineral particles entered the device from the flotation cell, subsequently rising to form a froth layer at the top of the device. The particles that detached or drained from the froth zone were collected in the dropback collection chamber whereas the concentrate sample was collected through a launder. By sizing and chemical analysis of the concentrate and dropback samples, the froth recovery was estimated on the basis of the valuable component. The effect of air rate on the froth recovery was also investigated. Metallurgical grades of the froth dropback device samples for different particle size ranges were compared to those of the concentrator to better understand the froth dropback mechanism.     

浮选过程中的泡沫夹带研究进展

细粒矿物浮选过程中,亲水的脉石矿物泡沫夹带进入精矿中,导致精矿品位降低。揭示泡沫排液及排脉石过程中的相关理论,可以为浮选泡沫结构及泡沫夹带行为的研究提供理论基础。浮选过程中的脉石泡沫夹带是一种普遍现象,脉石夹带回收率与精矿水回收率呈线性关系;两相泡沫排液受重力、毛细作用力(表面张力)、黏滞力控制,不同含液率的两相泡沫排液遵循不同的排液公式;三相泡沫的排脉石过程遵循对流—扩散模型,脉石的夹带回收率受三相泡沫排液速率及脉石颗粒浓度分布控制。浮选操作条件、亲水脉石的特性、矿浆特性以及泡沫结构是影响泡沫夹带的主要因素;优化浮选操作条件,改变浮选流程结构和改变药剂制度可以有效降低脉石的泡沫夹带,提高浮选选择性。未来,还需开发表征浮选三相泡沫特征的方法、装置或仪器,三相泡沫的结构及形态、疏水矿物颗粒与亲水脉石颗粒在泡沫中的运动路径及分布规律、浮选三相泡沫排液及排脉石的数学模型还需要进一步的细致研究。另外,降低脉石泡沫夹带的技术对于部分浮选体系虽有一定效果,但脉石的泡沫夹带尚难以消除,须开发一些革命性的技术。     

Effect of particle size on flotation performance of complex sulphide ores

Flotation processes occurring in the bulk and froth phases have a characteristic influence on the structural features and dynamics of the flotation froth. It is recognized that the structure and texture of a mineral froth is a good indicator of flotation separation performance. The surface froth feature and dynamics are presented by three features extracted from the digitized images of the froths, i.e. SNE, a rough indication of the average bubble size of the froth, froth stability and the average grey level of the froth, an indication of mineral loading. Particle size is an important parameter in flotation operation. Nowadays, particle size is often measured and controlled in flotation concentrators. In this study the dependence of the froth structures on the particle size variation was investigated on the batch flotation of a sulfide ore from the Merensky reef in South Africa, and the size by size recovery curves were studied as well. In general medium particles produced bubbles smaller than those observed in the presence of fine and coarse particles, and the recovery rates were larger. Entrainment was a contributory mechanism to the recovery of fine particles. The fluctuation of flotation indices on the particle size change can be diagnosed and predicted by the froth structures change with a high degree of accuracy.     

Application of hydrophobic and magnetic plastic particles for enhanced flotation recovery

The effect of hydrophobic and magnetic plastic particles having a contact angle of around 83° on flotation performance was evaluated using coal particles of varying degrees of floatability. The magnetic plastic material were recovered by a low intensity magnetic separator and recycled back to the flotation feed for re-use. Flotation rate tests conducted on coal using a conventional cell proved that combustible recovery and flotation rate were significantly enhanced with the addition of the plastic particles, especially for difficult-to-float coals, which was corroborated by flotation column tests. Carrying capacity and particle size-by-size flotation tests further showed that the magnetic plastic particles preferentially increased the recovery of coarse particles by as much as 35 absolute percentage points due to froth stabilization which reduced the selective detachment of coarse and/or weakly hydrophobic particles. The enhanced flotation recovery was attributed to the influence on liquid drainage rate in the froth zone, froth stability, bubble coalescence and flotation rates.     

基于极限树回归的浮选泡沫层厚度预测研究

泡沫浮选是一种重要的选矿方法，不同表面物理化学性质的矿物颗粒在药剂的作用下借助浮选机实现分离。浮选机的控制变量包括充气量、泡沫层厚度和药剂添加量等。泡沫层厚度是影响浮选指标的一个重要控制参数，同样，泡沫层厚度的准确测量也至关重要。传统的泡沫层厚度测量方式一般是采用传感器等装置来实现的，由于这些传感器往往需要与矿浆直接接触，所以有时会因机械故障或信号干扰而造成测量值的误差。 针对传统测量手段存在的问题，本文提出了一种浮选泡沫层厚度的软测量方法。运用极限树回归ETR方法，以浮选过程中原矿品位、入料流量、入料浓度、入料粒度、充气量、泡沫稳定度和泡沫移动速度为输入变量，建立预测模型，实现了浮选泡沫层厚度的有效预测。     

贫连生体浮选机理及粗选用浮选机发展方向的探讨

笔者在闹述贫连生体矿物浮选机理的同时,引入了贫连生休矿物与脉石矿物在泡沫相中下落时间差的概念,由此而发展了一种适于粗选的浮选槽,以尽早丢弃最终尾矿。     

On the collection of valuable minerals along rougher flotation banks

The collection of valuable minerals along rougher flotation banks was evaluated using top-of-froth measurements, which consist of sampling the froth surface. Considering non-selective froths observed in rougher flotation circuits, it was found the top-of-froth grades were similar to the bubble load grades, which allowed for a direct estimation of the collected mineral characteristics (size distribution, mineralogy, and grade). Thus, the flotation process evolution can be characterized by analyzing the collection of valuable minerals by true flotation instead of the classical mass balances approach, which strongly depends on the reliability of the tailings grade data. In addition, comparison among different valuable minerals was observed without significant sampling disturbances caused by solid entrainment.It is expected the top-of-froth measurement will be a useful tool for evaluating the effect of operating variables such as pulp conditioning, air flowrate and solids percentage on the true collection process along a flotation bank.     

无机盐阳离子对粉煤灰浮选泡沫稳定性的影响研究

粉煤灰中矿物组成的自然属性使得浮选脱炭体系的泡沫稳定性较差,从而影响了未燃炭的有效脱除。通过添加无机盐阳离子的方式来改变粉煤灰浮选矿浆体系的液相性质,研究了不同离子种类和含量对两相泡沫和粉煤灰浮选三相泡沫稳定性的影响,并进行了浮选验证。研究结果表明：无机盐阳离子的添加提高了泡沫的稳定性,阳离子价态越高,这种稳定作用就越明显。利用泡沫稳定性调节中的离子效应,对采自湖北黄石的粉煤灰样品进行了浮选脱炭的验证试验,结果表明：Fe3+对泡沫的稳定作用有效提高了粉煤灰的浮选脱炭效果,与空白浮选体系相比,在Fe3+浓度为3 mmol/L的条件下,浮选低炭灰烧失量由8.85%降低至5.57%,炭脱除率由41.94%提升至74.55%;与添加Fe3+的浮选体系相比,Mg2+和Na+对浮选指标的提高作用依次减弱。     

浮选泡沫相中现象及机理研究进展

泡沫相(层)是浮选重要组成部分之一,决定了最终精矿品位和整体浮选效率。由于泡沫相中的气泡与颗粒的相互作用比较复杂,近些年国内外学者围绕浮选泡沫层开展了大量相关研究。本综述在介绍浮选泡沫的结构和性质后归纳了浮选泡沫失稳的机理,即排液、粗化和兼并在现阶段的研究进展。对颗粒强化泡沫稳定性的相关机理进行了分析和总结,且归纳出颗粒疏水性、粒度和形状是颗粒影响泡沫层稳定的主要因素。之后回顾了泡沫层中常见的泡沫夹带现象,分析总结了泡沫夹带的三个主要机理;颗粒物理性质、水回收率、湍流强度、矿浆浓度、泡沫层性质和表观气速是影响泡沫夹带的主要因素;夹带模型的建立对脉石夹带程度的有效预测以及浮选工艺流程的优化具有重要意义。最后提出在今后的研究中加强泡沫相流体力学研究和推进泡沫层颗粒追踪技术是浮选泡沫相研究的方向之一。