煤泥浮选泡沫图像分割与特征提取

针对在煤泥浮选泡沫图像中的煤泥气泡互相粘连、边界模糊的情况,根据分水岭变换模拟浸水原理,提出一种新的、有效的分割算法,同时应用数学形态学中的腐蚀和膨胀算法,解决了经典分水岭算法不能处理的过分割和欠分割问题,使得粘连的煤泥气泡得到了有效的分割.然后计算出各个煤泥气泡的横截面积、周长、形状等物理特征参数,这些参数是实现自动控制浮选过程的重要依据.     

Estimation of platinum flotation grades from froth image data

Features extracted online from froth images on flotation plants are potentially useful to the development of advanced control for flotation systems, provided that these features can be related to the key indicator variables of the plant, such as valuable metal loadings and recovery. Although such relationships have been established in a number of base metal plants in industry, this is not the case in the platinum industry. In this paper, estimation of flotation grades and recoveries from froth image data is therefore considered based on laboratory and industrial plant data. It is shown that grades and recoveries can be reliably estimated from a number of different features by use of linear and nonlinear models. This includes simple colour information that on the industrial plant showed a strong correlation with grade measurement.     

Zircon mineral solids concentrated from Athabasca oil sands froth treatment tailings: Surface chemistry and flotation properties

Zircon mineral solids concentrated from Athabasca oil sands froth treatment tailings were compared by X-ray photoelectron spectroscopy, infrared spectroscopy, and collector-assisted froth flotation before and after surface cleaning in a low temperature, radio-frequency oxygen plasma. Plasma cleaning was effective at removing a surface bound layer of organic matter having chemical markers consistent with bituminous fractions. Specifically, the observation of long-chain aliphatics, ester and ether linkages, aromatic indicators, and hydroxyls in the absence of carboxylic acid groups, suggested the surface organic layer was representative of asphaltene or resin. Supporting this interpretation was the identification of pyrrolic and thiophenic chemical states. Plasma degradation of the hydrocarbon component transformed the zircon particles from hydrophobic to hydrophilic as evidenced by their recovery in water/ethanol froth flotation tests. The cleaned zircon particles were subsequently collected in the froth using dodecylamine. This work explains the surface conditions responsible for the reporting of zircon to the froth treatment tailings and demonstrates the efficacy of plasma cleaning as a means to condition zircon for coupling with collector agents. A physical model of surface adsorption is discussed and process implications are considered.     

煤泥浮选泡沫图像灰度行程及其统计纹理特征

针对煤泥浮选泡沫灰度图像统计纹理特征问题,通过实验室浮选柱试验,采集了大量的煤泥浮选泡沫图像,分析了泡沫图像的类别及特征,提出了描述浮选泡沫纹理特征的灰度行程矩阵提取算法,并进一步提取灰度行程矩阵的行程因子特征参数来描述浮选泡沫的视觉纹理特征,分析了各特征参数随浮选时间的变化关系.研究表明,泡沫灰度行程因子特征参数能够表征浮选泡沫图像纹理特征,并与特定的泡沫状态相关,可为煤泥浮选视觉监控系统提供泡沫状态信息.     

A new SEM-EDS based automated mineral analysis solution for PGM-bearing ores and flotation products

Reliable automated PGM identification is a consistent challenge on SEM-EDS based automated mineral analysis systems. The main reason for this is the size of the PGM grains, which are often smaller than 3 μm in diameter, particularly in chromitite ores of the Bushveld Complex. This leads to “mixed” X-ray (EDS) spectra, in which the relative PGM: gangue elemental contribution is variable. This is further complicated by the fact that PGM species often occur in the form of a solid solution series, and ideal chemical formulae of these minerals cannot be relied upon for automated mineral identification. These conditions make it difficult to automatically identify PGM species based on spectral matching or “windowed” elemental EDS X-ray analysis schemes.Mintek’s Mineralogy Division has developed and tested an algorithm that can identify PGM species from raw EDS spectral data, and largely overcomes the problem of mixed spectra. This PGM identification algorithm is being integrated as a plug-in into the Carl Zeiss SmartPI™ particle analysis software by the Carl Zeiss software team in Cambridge, UK, to provide a reliable automated PGM analysis system.     

基于像素匹配和卡尔曼滤波的运动估计在浮选泡沫流速特征提取上的应用

为了解决传统特征匹配算法难以准确提取浮选泡沫流速特征的问题,本文提出一种基于像素匹配和卡尔曼滤波相结合的算法。该算法首先综合考虑前后两帧图像上面像素点的流动,在基于理想情况下的灰度值不变、梯度时空不变以及运动连续性假设,提出使用欧拉-拉格朗日方程与计算数学最小化约束能量方程,得到的结果作为卡尔曼预测的观测值参与测量更新,从而在状态更新中得到最优的泡沫流速特征向量。实验结果表明,该算法计算准确,平稳性高,实时性好,可以很好地作为浮选机优化控制的原始参数。     

Assessment of the floatability of chalcopyrite,molybdenite and pyrite using biosolids and their main components as collectors for greening the froth flotation of copper sulphide ores

Biosolids and representative compounds of their main components – humic acids, sugars, and proteins – have been tested as possible environment-friendly collectors and frothers for the flotation of copper sulphide ores. The floatability of chalcopyrite and molybdenite – both valuable sulphide minerals present in these ores – as well as non-valuable pyrite was assessed through Hallimond tube flotation tests. Humic acids exhibit similar collector ability for chalcopyrite and molybdenite as that of a commercial collector (Aero 6697 promoter). Biosolids show more affinity for pyrite. The copper recovery (85.9%) and copper grade (6.7%) of a rougher concentrate obtained using humic acids as main collector for the flotation of a copper sulphide ore from Chile, were very similar to those of a copper concentrate produced by froth flotation under the same conditions with a xanthate type commercial collector. This new and feasible end-use of biosolids and humic acids should be new environment-friendly organic froth flotation agents for greening the concentration of copper sulphide ore. Now, further research is needed in order to scale current laboratory assays to operational mining scales to determine efficiencies to industrial scale.     

泡沫图像分析仪在浮选控制中的应用

本文回顾了国内外泡沫图像产品的应用情况,介绍了北京矿冶研究总院在泡沫图像产品方面取得的进展,提出了一种以泡沫图像处理系统(BFIPS)为主要检测单元,结合浮选机液位充气控制系统,稳产率调泡沫厚度的新浮选控制方案。该方案具有易调试,维护量少,效果显著的优点。