Effect of particle size on the surface oxidation and flotation behavior of galena particles in lime system

ABSTRACT

In this research, the effect of particle size on the surface oxidation and flotation behavior of galena in the lime system was studied. Coarse (?0.074 + 0.038 mm), intermediate (?0.038 + 0.025 mm) and fine (?0.025 mm) galena particles were used in the experiment. The dissolution tests, flotation tests, and sorption tests were accomplished. Through further analysis by XPS, the effect of particle size and lime was observed. The decrease of mineral particle sizes increased the adsorption ratio of collector and the dissolution of galena, while the hydrophilic product OH^?/Ca(OH)⁺ produced by dissolution occupied the dominant position, which led to the minerals hydrophilic.     

局部颜色特征与工艺参数融合的铜浮选入矿类型识别

针对铜浮选过程中矿源变化频繁而造成的浮选工况难以识别、生产过程不稳定等问题,在分析铜浮选流程特点的基础上,提出了一种局部颜色特征与关键工艺参数融合的铜浮选入矿类型识别方法.首先采用多元图像处理方法提取泡沫图像局部颜色特征,然后采用混合滤波、时间配准算法将其与关键工艺参数进行数据融合,最后用融合后的混合特征进行模糊聚类,得到隶属度矩阵和聚类中心.工业数据仿真结果验证了本文所提方法的有效性.     

稠油污水的有机组成及可生化性研究

采用物化-厌氧-好氧法处理稠油污水,对物化生化处理各阶段出水的有机组分进行定性分析,并对稠油污水的可生化性进行了进一步研究。研究结果表明:不同处理工序出水的有机成分差异较大,经过气浮、厌氧处理后,稠油污水可生化性逐步提高,有利后续好氧生物处理。     

基于预测与优先级缓存的MIPv6切换算法

为了提升移动IPv6的切换性能,保证实时性要求高的音频、视频等业务的服务质量,针对去除DAD过程的RDMIPv6方案未考虑在传输速率相对较慢的无线信道中,移动节点向NAR本地注册所产生的时延以及切换过程中引入的丢包问题,提出一种优化方案PCRD-MIPv6。PCRD-MIPv6方案结合基于L2触发的切换预测和数据包优先级缓存机制,在L2切换完成之前向移动节点MN维护的接入路由器缓存列表T_AR中的所有AR发送MOA实现本地注册,与此同时,将切换过程中的数据包按优先级缓存在PAR中,在切换完成后发往移动节点,从而减少切换过程中的丢包率。NS-2仿真结果表明,PCRD-MIPv6方案有效地减少了切换时延,降低了切换过程中的丢包率。     

Assessment of Bitumen Re c overy from the Athabasca Oil Sands Using a Laboratory Denver Flotation Cell

A methodology was developed in this study to evaluate the effect of operating parameters on the processability of oil sands using small‐scale laboratory experimental devices. By subtracting bitumen recovered to the froth by entrainment with water, the concept of “true flotation recovery” is proposed to describe bitumen recovery resulting from bitumenbubble attachment. The experimental results indicated that “true flotation recovery” is a more sensitive and meaningful marker than overall bitumen recovery to evaluate the processability of oil sands using small‐scale laboratory test units.     

Reliability analysis of a repairable duplex system

We analyse the survival time of a repairable duplex system characterised by cold standby and by a pre-emptive priority rule. We allow general probability distributions for failure and repair. Moreover, an important realistic feature of the system is the general assumption that the non-priority unit has a memory. This combination of features has not been analysed in the previous literature. Our (new) methodology is based on a concatenation of a Cauchy-type integral representation of the modified Heaviside unit-step function and a two-sided stochastic inequality. Finally, we introduce a security interval related to a security level and a suitable risk-criterion based on the survival function of the system. As a practical application, we analyse some particular cases of the survival function jointly with the security interval corresponding to a security level of 90.     

Hydrogen and Oxygen Bubble Attachment to a Bitumen Drop

Air bubble – bitumen attachment is a critical step in the flotation of bitumen from mined oil sand. In this study, single bubble – bitumen drop attachment was observed directly using a novel experimental technique. Induction time is determined and used as an indication of bubble‐bitumen attachment potency for both hydrogen and oxygen bubbles. The attachment tests were conducted in deaerated municipal water (City of Edmonton tap water) at temperatures ranging from 22–50°C. Induction times measured for hydrogen bubble attachment were shorter than those for oxygen bubbles. Coalescence tests were also conducted in the absence of bitumen, and showed that hydrogen bubbles coalesced more rapidly than oxygen bubbles in both deaerated municipal water and clear (solids‐free) process water.     

FJCR12-4型喷射式浮选机在太西选煤厂的应用

介绍太西选煤厂将XJX T12型机械搅拌式浮选机改造为FJCR12 4型喷射式浮选机的过程,分析了这两类浮选机清水性能试验和生产试验的结果。实践表明,FJCR12 4型浮选机处理量大,动力和浮选药剂消耗少,能回收大于0 5mm及0 5～0 25mm的粗粒煤,具有良好的经济效益。     

用唐钢石人沟铁精矿生产超级精矿

以石人沟铁矿精矿粉为原料生产超级铁精矿，进行了磨矿—反浮选、分级—反浮选和分级—低磁场磁选等试验，并按磨矿—反浮选方案建成了生产超级铁精矿的选矿厂。实践证明阳离子反浮选是生产低硅高纯铁精矿的可靠工艺。     

Modelling Gas Holdup in Flotation Column Froths

A one‐dimensional steady‐state model is developed for the prediction of axial variation of the gas holdup in flotation column froths. Froth is considered as an inverse fluidized bed of bubbles and hence the frictional pressure gradient is obtained based on the energy balance. Pressure gradient can also be obtained from the Ergun equation with adjustable constants. The model correctly captures the effect of superficial gas velocity, superficial liquid velocity and bubble diameter on the variation of the gas holdup along the froth height. The predictions of the model are in agreement with the experimental data from the literature.