An experimental study of the recovery of hydrophilic silica fines in column flotation

This paper presents results of tests performed to investigate the effect of gas rate (1.2–2.5 cm/s), hydrophilic fines content (5–20% w/w silica) and froth depth (10–30 cm) on fines recovery in a laboratory-scale flotation column operating without wash-water addition and absence of floatable particles. A model was developed based on the entrainment coefficients presented by [Trahar, W.J., 1981. A rational interpretation of the role of particle size in flotation. International Journal of Mineral Processing 8, 289–327], which describes the mass contribution of the different size classes to the solids recovered in the concentrate. The entrainment model of [Zheng, X., Johnson, N.W., Franzidis, J.P., 2006. Modelling of entrainment in industrial flotation cells: water recovery and degree of entrainment. Minerals Engineering 19, 1191–1203] was also tested. The results show both models described well the dependence of the mass flow rate of hydrophilic solids in the concentrate.     

Arsenopyrite enrichment by column flotation

Arsenic-rich, gold-bearing pyrite concentrates may be further enriched in arsenic to assist subsequent Au beneficiation. Among several amines tested in refloating a local Chalkidiki pyrite concentrate, 2-coco 2-methyl ammonium chloride proved successful by raising the grade from 9% to 22%, although total solids recovery was low. The use of a froth-stabilizing frother was also benefecial to the process. Optimum hydrohynamic conditions were: intermediate pulp flowrate, low wash water and gas flowrate; the latter abated the mixing/dispersion process in the collection zone.     

煤粉粒度测试技术现状及发展

介绍了目前国内外有关煤粉粒度分布测试技术的各种手段和方法,综合评述了其技术现状和特点,比较了各种测试方法的优缺点.     

The mixing characteristics of solid and liquid phases in a flotation column

This paper presents results obtained in determining the residence time distribution (RTD) characteristics of the solid and liquid phases in a laboratory column and two industrial columns using radioactively labelled solid and liquid tracers. The dispersion model is shown to be superior to other models in describing the RTD in columns with diameter between 10cm and 150cm. Smaller diameter columns can be modelled using either the dispersion model or the tanks-in-series model and larger columns can be modelled using the latter model. Feed and gangue material produce similar tailings age distribution curves. The solid dispersion coefficient is larger than the liquid dispersion coefficient. The solid dispersion coefficient increases with increasing particle size in the laboratory column but remains constant with increasing particle size in the large columns. A modified correlation is proposed to predict the solid dispersion coefficient in large columns.     

浮选柱与浮选机分选煤泥的试验研究

旋流气泡浮选柱是近年来广泛推广使用的浮选设备,通过分析浮选柱的工作原理及优点,进行浮选柱与浮选机的对比试验研究。结果表明:细粒煤分选时,浮选柱比浮选机具有明显的优势。     

An evaluation of the role of particle size in the flotation of coal using different cell technologies

A large variety of new flotation cells has been introduced in the last few years, probably as a result of the successful introduction of column flotation in the minerals processing industry. In common with the column cell, a number of these new cells employ an essentially quiescent separation zone. However, a number of novel cell designs have been introduced that use agitation mechanisms similar to those employed on conventional flotation cells. The aim of this investigation was to evaluate flotation behaviour in both an agitated and non-agitated environment, particularly with respect to particle size. A hybrid ‘agitated’ column cell was designed for the investigation, and the operation of this unit was compared to that of a column cell, and to a batch flotation cell, on a laboratory scale. The testwork was conducted on coal fines, as problems with the flotation of coarse coal particles in a column cell had previously been identified. It was demonstrated that the addition of an agitated stage to a column cell can significantly improve the coarse particle recovery in comparison to the conventional column cell, while maintaining good selectivity in the fine sizes.     

旋流-静态微泡浮选柱用于铜精选的试验研究

为提高某斑岩型铜矿的精矿品位,引入旋流-静态微泡浮选柱进行精选工艺试验研究,以浮选柱两段替代原浮选机五段精选流程,可获得品位为26.45%的铜精矿,精选作业回收率达93.66%,并有利于金、银、钼等伴生金属的富集和回收.     

气肥煤浮选降灰试验研究

为考察山东济北矿区气肥煤煤泥降灰的可行性,分别以柴油和仲辛醇(分析纯)为浮选药剂,采用拓展化浮选试验的方法,重新设计浮选流程,对煤泥进行了粗选试验和一次精选试验.试验结果表明:最佳浮选药剂用量为1.0 kg/t、药剂比为5:1,矿浆浓度为80 g/L、搅拌速度为1 800 r/min,精选多次刮泡条件下,时间累计在15...     

Development of an index for the floatability of Indian coal fines

Batch flotation experiments were carried out on four different Indian bituminous coal samples in the size -74 μm at various levels of variables. It has been noticed from the results that at any flotation time, the yield of concentrate Y (t) follows a linear relationship of the following form with the amount of water W(t) reporting to the concentrate. Y(t)=F_w(t)+E_w(t)·W(t)The intercept value F_y(t) which is termed as the true flotation component of yield when hypothetically no water reports to the concentrate has been found to increase with flotation time as given by the equation F_w(t)=F_w(∞)·[1−exp(−k_w·t)]Based on these observations, an index called “floatability index (FI)” has been proposed to quantify the response of coals towards froth flotation. This index is defined as The floatability index varies from 0 to 100. Consequently, the higher the value of the index for any coal, the better is its response towards flotation. The floatability index has been found to be specific for a given coal and is independent of process variables like reagent dosages, solid content of feed slurry and flotation time.     

中心选煤厂煤泥浮选工艺改造

为解决新矿内蒙能源公司中心选煤厂精煤综合产率低的问题,决定采用FCMC型旋流微泡浮选柱对原生产工艺进行改造。实践结果表明:旋流微泡浮选柱分选工艺在该厂的应用不仅满足了精煤灰分≤8.50%的要求,提高了精煤综合产率,而且为企业带来丰厚的利润。     

浮选柱及精煤压滤机回收煤泥的实践研究

分析了兴发选煤厂煤泥水处理系统的改造原因,并介绍了改造后的工艺流程主要特点,指出在原料煤性质、入料浓度相同的情况下,采用以浮选柱与加压过滤机作为浮选精煤压滤机联合使用,可提高选煤厂煤泥水处理能力和精煤产率。     

煤泥浮选工艺参数对浮选指标影响的试验研究

采用XFDⅣ型浮选机对汾西紫金矿选煤厂浮选入料进行浮选试验,研究了浮选机充气量、叶轮转速和药剂配比及用量对煤泥浮选指标的影响。试验结果表明:当浮选机充气量为150 L/h、转速为1 800 r/min,捕收剂和起泡剂配比为4∶1,捕收剂和起泡剂用量分别为1 200 g/t和300 g/t时,浮选效果最好。     

王楼煤矿选煤厂煤泥浮选试验研究

为解决王楼煤矿选煤厂煤泥水系统存在的问题,对该厂煤泥进行了粒度分析和浮选试验。研究结果表明:煤泥中高灰细泥含量高,影响浮选效果;在相同药剂制度下,浮选柱在降低精煤灰分和提高精煤产率方面优势明显。经预测,该厂浮选系统改造后每年可增加毛利润5 000万元,经济效益可观。     

Reverse flotation of coal—A novel way for the beneficiation of coal fines

South African coals have a much higher ash content than European coals. Consequently, ash entrainment is often a problem in the flotation of South African coal, since it adversely affects the concentrate grade. It has thus been very difficult to produce a low ash metallurgical export coal by this process. This paper presents a novel method aimed at reducing entrainment, viz. reverse flotation. The method involves the simultaneous flotation of the ash and the depression of the coal using cationic amine surfactants. Initial flotation testwork on liberated coal/ash mixtures has shown the excellent ash collecting ability of quaternary amines. For example, a concentrate ash recovery of 92% was achieved from a feed “coal” with an ash content of 54%. The tailings (ie product) ash was 12%. Coal depression was less successful; in the same experiment coal recovery into the concentrates was 27%. Improving the coal depression by altering the pH is being investigated.     

浮选柱串联处理高浓度煤泥水效果初探

分析了浮选作业现状,阐述了浮选入料性质特别是入浮浓度对浮选柱分选效果的影响,提出了采用浮选柱串联解决高浓度浮选的新方法,并通过试验论证了该方法的可行性,对工业现场的浮选作业具有一定的指导意义.     

Supervisory control of flotation columns using multi-objective optimization

This work describes a method for supervisory control of flotation columns based on predictive trajectory generation of setpoints to be applied to the local controllers of the process. The system maximizes the profit while keeping quality constraints and engineering indices. It represents an advance over predictive supervisors using a single evaluation function or those that reduce a multi-objective problem to a single-objective one by means a weighted sum. The procedure is founded on multi-objective optimization using non-dominated genetic algorithms, and a new classification criterion of the Pareto optimal set. The system has been tested by simulation against usual perturbations affecting the flotation process and exhibits good performance, provided that the model properly represents the system operation.     

浮选精煤掺粗对其脱水效果的影响

浮选精煤粒度过细会造成浮选消泡困难、浮选精煤水分高等问题,而合理的向浮选精煤中掺入粗颗粒,改善其粒度组成,有利于解决这些问题。通过试验论证了浮选精煤掺粗有利于浮选精煤消泡,并可有效降低浮选精煤水。     

浮选柱分选-0.18mm细粒煤泥的实验室试验和工业应用

对古城选煤厂-0.18mm煤泥的浮选机和旋流微泡浮选柱进行了对比试验,试验结果表明,在细粒煤泥分选方面,旋流微泡浮选柱比浮选机更具有一定的优势,FCMC-4500型旋流微泡浮选柱在古城选煤厂取得了良好的工业应用效果。     

煤泥浮选工艺流程的探讨

概述了一次浮选、二次浮选、二次尾矿或中矿返回浮选三种典型煤泥浮选工艺流程,阐述了以煤泥可浮性试验结果为依据,合理选择和制定浮选工艺流程的设计思路和方法,指出大型选煤厂往往煤源广泛、煤质差异大,应采用可灵活转换一次浮选与二次浮选的工艺流程。     

浮选尾煤截粗系统在煤泥水系统中的应用

介绍了吕家坨选煤厂在回收浮选尾煤中的粗粒煤、降低煤泥水系统的处理压力和提高尾煤的经济效益等方面的经验,并阐述了在煤泥的深度处理、煤炭产业的产品结构方案优化与实践等方面的探索。