Electro-flotation and collision-attachment mechanism of fine cassiterite

In order to discuss the particle-bubble interaction during the electro-flotation of cassiterite,the recovery of cassiterite with different particle sizes was investigated,and the collision mechanism between the cassiterite particles and H2 bubbles was explored.The flotation tests were carried out in a single bubble flotation cell.The results show that cassiterite particles 10 μm,10-20 μm,20？38 μm and 38-74 μm match with bubbles with size of 50-150 μm,about 250 μm,74 μm and 74 μm,respectively,and a better recovery can be obtained.It is demonstrated that the recovery of cassiterite is influenced by the size of cassiterite particles and bubbles.Furthermore,the probabilities of collision,adhesion,detachment and collection were calculated using the collision,attachment and collection models.Theoretical calculation results show that the collision probability decreases sharply with decreasing particle size and increasing bubble size（below 150 μm）.The attachment probability would increase from the effective collision,leading to the increase of recovery.

Modeling of fine coal flotation separation based on particle characteristics and hydrodynamic conditions

Flotation is a complex multifaceted process that is widely used for the separation of finely ground minerals. The theory of froth flotation is complex and is not completely understood. This fact has been brought many monitoring challenges in a coal processing plant. To solve those challenges, it is important to understand the effect of different parameters on the fine particle separation, and control flotation performance for a particular system. This study is going to indicate the effect of various parameters （particle Characteristics and hydrodynamic conditions） on coal flotation responses （flotation rate constant and recovery） by different modeling techniques. A comprehensive coal flotation database was prepared for the statistical and soft computing methods. Statistical factors were used for variable selections. Results were in a good agreement with recent theoretical flotation investigations. Computational models accurately can estimate flotation rate constant and coal recovery （correlation coefficient 0.85, and 0.99, respectively）. According to the results, it can be concluded that the soft computing models can overcome the complexity of process and be used as an expert system to control, and optimize parameters of coal flotation process.

Nano-microbubble flotation of fine and ultrafine chalcopyrite particles

As is well known to mineral processing scientists and engineers, fine and ultrafine particles are difficult to float mainly due to the low bubble-particle collision efficiencies. Though many efforts have been made to improve flotation performance of fine and ultrafine particles, there is still much more to be done. In this paper, the effects of nano-microbubbles （nanobuhbles and microbubbles） on the flotation of fine （-38 ＋ 14.36 μm） and ultrafine （-14.36 ＋ 5μm） chalcopyrite particles were investigated in a laboratory scale Denver flotation cell. Nano-microbubbles were generated using a specially-designed nano- microbubble generator based on the cavitation phenomenon in Venturi tubes. In order to better under- stand the mechanisms of nano-microbubble enhanced froth flotation of fine and ultrafine chalcopyrite particles, the nano-microbubble size distribution, stability and the effect of frother concentration on nano- bubble size were also studied by a laser diffraction method. Comparative flotation tests were performed in the presence and absence of nano-microbubbles to evaluate their impact on the fine and ultrafine chalcopyrite particle flotation recovery. According to the results, the mean size of nano-microbubbles increased over time, and decreased with increase of frother concentration. The laboratory-scale flotation test results indicated that flotation recovery of chalcopyrite fine and ultrafine particles increased by approximately 16-21% in the presence of nano-microbubbles, depending on operating conditions of the process. The presence of nano-microbubbles increased the recovery of ultrafine particles （-14.36 ＋ 5 μm） more than that of fine particles （-38 ＋ 14.36 μm）. Another major advantage is that the use of nano-microbubbles reduced the collector and frother consumptions by up to 75% and 50%, respectively.

An effective approach for improving flotation recovery of molybdenite fines from a finely-disseminated molybdenum ore

An effective flotation approach is proposed for improving the recovery of molybdenite fines from a finely-disseminated molybdenum ore. To maximize the flotation recovery of molybdenum, process mineralogy of raw ore, contrast tests, optimization of operation conditions and particle size analysis were systematically investigated. Process mineralogy suggests that in the raw ore, 61.63% of molybdenite particles distribute in the 〈20 pm size fraction, and intergrow with muscovite and pyrite as the contained and disseminated type. Contrast tests indicate that conventional flotation responds to poor collection efficiency for particles less than 25 pm. Oil agglomerate flotation （OAF） process demonstrates an obvious superiority in improving the flotation recovery of molybdenite fines. Furthermore, the flotation results of OAF process reveal that the dosage of transformer oil plays a critical role on the average size of collected mineral particles （d（0）, agglomerates （d^0） and the molybdenum recovery. In addition, industrial tests illustrate that compared with the Mo-S bulk flotation approach, OAF process not only increases Mo recovery and grade of molybdenum concentrate by 22.75% and 17.47% respectively, but also achieves a sulfur concentrate with a superior grade of 38.92%.

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.

Collision and attachment behavior between fine cassiterite particles and H_2 bubbles

Particle-bubble interaction during electro-flotation of cassiterite was investigated by determining the recovery of cassiterite and the collision mechanism of cassiterite particle and H2 bubble. Flotation tests at different conditions were conducted in a single bubble flotation cell. The recovery of cassiterite was found to be affected by cassiterite particle and bubble size. A matching range, in which the best recovery can be obtained, was found between particle and bubble size. Collision, attachment, and detachment of the particle-bubble were observed and captured by a high-speed camera. Particle-bubble collision and attachment were analyzed with the use of particle-bubble interaction theory to obtain the experimental results. An attachment model was introduced and verified through the photos captured by the high-speed camera. A bridge role was observed between the bubbles and particles. Particle-bubble interaction was found to be affected by bubble size and particle size, which significantly influenced not only the collision and attachment behavior of the particles and bubbles but also the flotation recovery of fine cassiterite particles.

Observation of fine particle aggregating behavior induced by high intensity conditioning using high speed CCD

The aggregating behavior between bubbles and particles induced by high intensity conditioning (HIC) was studied using high speed CCD technique. Bubble size measurement was conducted, and the attachment behavior between bubbles and particles in HIC cell and flotation cell were observed. The results show that in HIC cell, high intensity conditioning creates an advantage environment for the formation of small size bubble due to hydrodynamic cavitations, and these fine bubbles have high probability of bubble-particle collision, which will enhance fine particle flotation. The bubble-particle attachment experiments indicate that in high intensity conditioning cell, a lot of fine bubbles are produced in situ on the surface of fine particles, and most of fine particles are aggregated under the bridging action of fine bubbles. The observation of bubble-particle interaction in flotation cell illustrates that aggregates created by HIC can be loaded more easily by big air bubble in flotation cell than those created by normal conditioning.

Effect of high intensity conditioning on aggregate size of fine sphalerite

High intensity conditioning(HIC)was used as a model to study the fundamental of fine sulphide particle flotation.The effect of impeller design,mechanical energy input,and agitation speed on aggregate size of fine sphalerite was tested.The aggregate size of fine sphalerite was measured with the Malvern Hydro 2000 Mastersizer.The results show that the size of aggregates of sphalerite particles ground for 3 min can be enlarged significantly with the activator and collector addition in HIC using the high energy impeller.The improved particle aggregation by using the high energy impeller is not directly related to a higher energy input into the system.With the same energy input into HIC,the aggregate size obtained with the high energy impeller is much coarser than that obtained with the low energy impeller.With the new impeller in HIC,the sphalerite aggregate size decreases with increasing agitation speed from 700 to 2 500 r/min.However,the recovery does not decrease until the agitation speed reaches 2 500 r/min.

微细粒矿物浮选综述:增大颗粒表观尺寸与减小气泡直径

微细粒矿物的浮选回收是世界性难题,增大颗粒表观直径与减小气泡尺寸为解决该难题的有效途径。论文综述了增大颗粒表观直径的四种方法:疏水絮凝浮选、载体浮选、选择性絮凝浮选和剪切絮凝浮选,详细阐述了其在矿物加工领域中的应用及机理,尤其是增大颗粒表观粒径过程中新药剂的最新研究进展及应用领域。从减小气泡尺寸角度出发,以微纳米气泡在矿物加工领域的应用研究为落脚点,阐述了微纳米气泡现有的稳定性机理,为后续微纳米气泡稳定性机理的深入研究提供参考;系统介绍了微纳米气泡在不同种类微细粒矿物浮选中的应用现状;从微纳米气泡与颗粒间界面作用机理出发,详细阐述了微纳米气泡在界面作用中的角色;举例介绍了微纳米气泡浮选设备的研究进展。提出微纳米气泡强化细粒浮选的机理需要进一步明确,基于微纳米气泡、矿浆精准可控的微纳米气泡浮选设备是微细粒矿物浮选的重要研究方向。

甘肃某细粒铅锌矿工艺优化试验研究

甘肃某铅锌矿中铅品位为0.74%,锌品位为3.72%,为了实现该矿产资源的高效回收利用,针对铅锌矿物嵌布关系紧密,粒度较细,造成铅锌精矿互含量较高,影响浮选指标的问题,在原矿性质研究的基础上,进行了4种不同方案的工艺流程对比试验。试验结果表明:采用铅锌优先浮选—铅、锌粗精矿均再磨的工艺流程,最终获得的铅精矿铅品位为58.42%,铅回收率为79.95%,锌精矿锌品位为56.27%,锌回收率为93.05%。相较于方案2,锌精矿锌品位提高了3.03个百分点,锌回收率提高了2.75个百分点;相较于方案1现场生产工艺,铅、锌主品位提高,铅、锌互含量显著降低,锌回收率提高了4.15个百分点。

筛分—反浮选联合脱杂法制备精光卤石工艺研究

针对察尔汗盐湖产出的高杂质光卤石矿质量差、难以生产利用的情况,本研究以该光卤石矿为原料,采用反浮选工艺和筛分脱除细粒级—反浮选联合工艺分别进行脱除杂质试验研究。结果表明:相比反浮选工艺,联合工艺可以通过脱除-0.088 mm/-0.074 mm细粒级,预先脱除56.36%/41.22%的钠杂质及92.56%/87.79%的钙杂质,再联合一次粗选,两次扫选,粗选精矿与扫选精矿合并的反浮选工艺流程,使Na^(+)、Ca^(2+)脱除率均达到90%以上。脱杂后精光卤石中的K^(+)品位较原矿提高了1.1倍,精光卤石品质能够满足后续生产要求,可以实现该矿正常生产利用,并且该工艺能够显著降低药剂用量,在产品品质及选矿成本上具有较大优势。

纳米气泡浮选过程强化研究进展

浮选是低品质矿及煤分选提质的有效手段,其中微细粒浮选难题突出,而纳米气泡则是解决该难题的重要途径,但关于纳米气泡浮选过程强化的诸多基础科学问题仍未解决。为促进微细粒纳米气泡浮选过程强化技术的开发,重点围绕浮选过程中纳米气泡的界面选择性成核动力学、界面纳米气泡超常稳定性机理及纳米气泡强化颗粒-气泡捕获效率微观作用机制等三个关键科学问题,介绍了笔者团队在纳米气泡浮选过程强化方向的最新研究进展。研究结果表明:纳米气泡的选择性成核是纳米气泡浮选过程强化的关键,而纳米气泡的稳定性则是纳米气泡浮选过程强化的前提;纳米气泡浮选过程强化的机制主要包括促进颗粒絮团与缩短诱导时间,其内在作用机制来自纳米气泡长程疏水引力与边界滑移的协同作用。笔者团队的研究阐明了纳米气泡固-液界面选择性成核的能量作用机制,提出了基于界面高密度气层自动补偿的界面纳米气泡稳定性机理,建立了微纳力学-边界滑移协同驱动的纳米气泡强化浮选界面作用机制,进一步丰富发展了现代浮选基础理论,为开发微细粒纳米气泡浮选过程强化技术提供了一定的指导。

云南某细粒铜钼混合精矿分离工艺优化及工业应用

云南某细粒硫化铜钼混合精矿中主要有价金属元素为铜和钼,矿石中主要矿物为黄铜矿和辉钼矿,脉石矿物主要是石英和云母,铜、钼矿物嵌布粒度较细,与脉石矿物复杂共生。针对混合精矿分离难度大、分离指标较差、药剂单耗用量大、药剂成本高的现状,结合混合精矿含钼品位的上升,在工艺矿物学研究基础上,开展了选矿试验研究。通过对原有工艺及药剂制度进行优化试验,研制了新型铜钼分离药剂D117和D118,其中D117为铜抑制剂,D118为调整剂。在原矿铜品位20.75%、钼品位0.47%的条件下,采用“抑铜浮钼”、一次粗选、四次精选、一次扫选浮选工艺,获得钼品位45.15%、铜品位1.03%、钼作业回收率85.65%的钼精矿及含钼0.069%、铜品位20.92%、铜作业回收率99.96%的铜精矿,取得了良好的实验室选别指标。将研究成果应用于工业生产后,浮选浓度由18%提升至33%,系统台效由17.4 t/h提高至25.9 t/h,钼作业回收率由66.11%提升至80.55%,年产钼金属由286 t提高至710 t。同时,D117、D118新型小分子药剂的使用取消了水玻璃的添加,并大幅降低了硫化钠用量,硫化钠粗选用量由设计之初125000 g/t降至6000 g/t,降幅达95.20%。通过药剂制度的持续优化,进一步压缩了硫化钠用量,硫化钠单耗由13.4 kg/t降至7.53 kg/t,D117单耗由6.18 kg/t降至3.98 kg/t,在药剂成本大幅度降低的前提下,实现了铜钼分离系统处理量及生产指标的双提升。

MO捕收剂对煤气化细渣浮选性能的影响

这是一篇矿物加工工程领域的文章。煤气化细渣的综合利用是现阶段的一大发展方向。煤气化细渣孔隙发达且含氧基团丰富,使得煤油等传统捕收剂难以回收其中的残炭。将油酸甲酯和煤油复配得到的药剂MO进行浮选实验,并通过激光粒度仪、红外光谱分析、接触角分析、XPS分峰拟合等手段进行机理探讨。结果表明,当MO药剂用量提高到16 kg/t时,尾矿烧失量降低到7.12%,可燃体回收率超过95.63%。MO药剂引入了极性基团酯基,其可以降低煤油表面的界面张力,增强捕收剂在水中的分散作用,从而增加残炭颗粒与捕收剂液滴的接触面积与碰撞概率,进而提高残炭颗粒的疏水性和可浮性。通过接触角分析不同药剂作用下残炭表面的疏水性,解释其与精矿产率的关系。通过XPS分析说明,MO与残炭表面的含氧官能团作用,能够在残炭的亲水位点形成有效的覆盖层,使得疏水部分朝外,降低了水化作用,增加了接触概率,增加该煤气化细渣的表面疏水性。MO药剂的使用为煤气化固体废弃物的综合利用提供了一种新途径。

某微细粒伴生银萤石矿选矿试验研究

某萤石矿伴生少量黄铁矿、自然银和辉银矿,且萤石矿、黄铁矿、自然银和辉银矿等有用矿物的嵌布粒度极细,需细磨方可有效解离。针对该矿石特点,进行细磨(-0.074mm占92.59%),经“优先选银—再选萤石(碱性粗选、再磨弱酸性精选)”流程,可获得银品位1934.79g/t、银回收率70.31%的银精矿和萤石品位97.35%、萤石回收率78.72%的萤石精矿,萤石精矿含CaCO_(3)仅0.77%,取得了较好的选矿效果。

微细粒浮选技术与装备研究进展及其发展趋势

随着矿产资源的开发和利用,贫、细、杂的矿物资源将越来越成为资源的主体来源,人们面临着如何高效利用这部分资源的问题;同时,为了使低品位的矿床能够经济开采,微细颗粒的浮选显得尤为重要。本文分析了微细粒矿物浮选过程中遇到的瓶颈问题,在此基础上分析并归纳了近年来人们针对微细粒难以浮选的问题采用的新技术和新方法。最后,分析了微细粒浮选装备需要满足的流体动力学条件,总结了近年来微细粒浮选装备的发展,并对未来微细粒浮选技术和装备的发展趋势进行了展望。

镍钼矿选矿工艺分析

镍钼矿选矿是有价元素提取的关键过程,会为后续矿产资源开发奠定基础。本案例中的镍钼矿中镍含量为0.52%、钼含量0.74%,呈现出集合产出形态。为实现对矿产资源的良好开发,按照工艺流程脱质后,将CMC作为抑制剂,使用浮选工艺处理,选矿实验得到的镍、钼回收率,分别为81.22%、72.55%,有利于降低后续矿产焙烧投入的成本,提高镍钼矿冶炼效率。

微细粒矿物载体浮选技术研究进展

微细粒矿物由于其特殊的物理化学性质,采用常规选矿方法浮选效率低。载体浮选作为一种有效的微细粒矿物浮选技术,通过采用合适的载体,可显著提高微细粒矿物的浮选效率。阐述了微细粒矿物的表面性质与浮选行为,以及载体浮选的基本原理,载体与微细粒矿物的相互作用机制。分析了微细粒矿物载体浮选技术的研究及应用现状,对载体浮选的影响因素进行了归纳。针对同类载体、异类载体和分支载体三种载体浮选,指出了各类载体浮选的特点和优缺点,并展望了其未来发展趋势,旨在为载体浮选的进一步工业应用提供参考。

新疆某含羟硅铍石矿分选实验

这是一篇矿物加工工程领域的论文。以新疆某次火山岩型铍矿石为研究对象,进行矿物组成、元素组成分析,查明有用矿物的嵌布粒度及赋存状态,并进行系统的浮选实验。在磨矿过程加入活化剂氟化钠,对磨矿细度、浮选药剂制度进行了优化,当磨矿细度为-0.074 mm 85%、pH值调整剂碳酸钠、抑制剂硅酸钠、捕收剂油酸钠用量分别为1500、1000、2000 g/t时,可以获得粗选精矿BeO品位6.03%、回收率97.02%的粗选指标。将粗选精矿再磨至-0.045 mm 90%,通过两次精选实验,精矿BeO品位达到8.40%,精矿BeO回收率为78.09%,粗选尾矿经过一次扫选实验,尾矿BeO含量可降至0.003%。“一粗一扫三精、中矿集中返回粗选”的浮选闭路实验,获得了精矿BeO品位8.12%、回收率80.99%的浮选指标,可以实现羟硅铍石的较好富集,满足我国当今铍冶炼工艺对原料BeO含量的要求。

疏水-亲水分选研究进展

这是一篇矿物加工工程领域的论文。疏水-亲水双液分选相较于泡沫浮选在微细粒(煤30~50μm、非煤矿物10~20μm)回收方面有较大优势。基于油团聚、奥蒂斯卡工艺、驱替脱水、双液浮选和低沸点非极性液体回收等开发的新型疏水-亲水双液分选技术(Hydrophobic-hydrophilic Separation)能够促使超细粒团聚体在双相系统中充分破碎再分配,从而达到驱水除杂的双重目的。从HHS选煤过程、团聚体破碎理论、疏水液体回收可行性、相较于泡沫浮选和油团聚的技术优势以及细粒煤脱水技术等方面对疏水-亲水分选近些年的发展进行梳理比较,以期能够为下一步发展提供参考建议。