Process mineralogy of copper-nickel sulphide flotation by 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 micro-scope-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.     

浮选柱反浮选胶磷矿的影响因素

浮选柱是一种高效的细粒物料分选设备,但应用于胶磷矿浮选仍然受诸多因素制约.为考查浮选柱结构特征、工作参数和操作条件等因素对其分选效果的影响,采用试验室浮选柱对贵州瓮安磷矿进行了单一反浮选试验,重点研究了矿浆浓度、药剂用量、筛板充填方式和充气量对浮选柱反浮选效果的影响.结果表明,在磨矿细度为-0.074 mm占88％、矿浆浓度为25％（质量分数）、油酸钠用量为1.8 kg/t、硫酸用量为5 kg/t和充气量为400 L/h时,反浮选的分选效果较好.由于浮选柱可以通过充填筛板来改善其分选环境,因此在较优条件下,其分选效率比用浮选机时高1.57％.     

A honeycomb-tube packing medium and its application to column flotation

We address problems in the development of large-scale flotation columns that use short cylinders. As a starting point, we investigated the packing medium to identify a highly efficient internal packing for the flotation column. The chosen packing was a honeycomb structure with an aperture diameter of 80 mm, a web thickness of 0.80 mm, a film height of 1000 mm, packed into a 400 mm diameter space, which completely filled the vessel at optimal cost. The column consisted of a modular ring of single-hole hexagonal honeycomb tube packing made from atactic polyproplene (PP-R). The packing was tested in a cyclonic, static mi-cro-bubble flotation column. Computational fluid dynamic modeling was used to analyze the flotation fluid in a honeycomb tube packed flotation column. Our results show that the fluid axial movement was maximized and that the transverse fluid velocities were zero in the vicinity of axial flow. Using the honeycomb tube packing for copper sulfide flotation we observed that the average concentration in the product was increased to 25.41%, from an average feed concentration of 0.729%, with an average recovery of 92.92%. The demands of on-site industrial production were met.     

Group separation and analysis of a carbon disulfide-soluble fraction from Shenfu coal by column chromatography

A carbon disulfide-soluble fraction (CDSSF) from Shenfu coal was separated into five fractions by silica-gel column chromatography using hexane and n-hexane/ethyl acetate binary eluent. The five fractions include four clear group fractions and a nonpolar fraction. All the fractions were analyzed by GC/MS. A total of 204 compounds were detected from the original CDSSF and its further separated fractions, with 173 compounds more than those detected by studying the original CDSSF directly. The results demonstrate a clear group separation by column chromatography in coal organic components and a more accessibility to coal components compared with the solvent extraction only.     

Desulfurization of coal by an electrochemical-reduction flotation technique

The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCI solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied.The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2 and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.     

Prediction of operational parameters effect on coal flotation using artificial neural network

Artificial neural network procedures were used to predict the combustible value (i.e. 100-Ash) and combustible recovery of coal flotation concentrate in different operational conditions. The pulp density, pH, rotation rate, coal particle size, dosage of collector, frother and conditioner were used as inputs to the network. Feed-forward artificial neural networks with 5-30-2-1 and 7-10-3-1 arrangements were capable to estimate the combustible value and combustible recovery of coal flotation concentrate respectively as the outputs. Quite satisfactory correlations of 1 and 0.91 in training and testing stages for combustible value and of 1 and 0.95 in training and testing stages for combustible recovery prediction were achieved. The proposed neural network models can be used to determine the most advantageous operational conditions for the expected concentrate assay and recovery in the coal flotation process.     

Numerical simulation of a self-absorbing microbubble generator for a cyclonic-static microbubble flotation column

The Cyclonic-Static Microbubble Flotation Column (FCSMC) is currently a widely used, novel type of flotation device. The self-absorbing microbubble generator is the core component of this device. The structure of the microbubble generator directly influences flotation column performance by affecting bubble size and distribution as well as gas holdup in the column. However, the complicated flow inside the generator results in high R&D costs and difficulty in testing. Thus, the CFD software, FLUENT, was used to simulate the gas-liquid two-phase flow inside a self-absorbing microbubble generator. The effect of area ratio, a key structural parameter, was studied in detail. Critical flow-field parameters including velocity, turbulent kinetic energy, minimum static pressure and gas holdup were obtained. The simulation results demonstrate that the optimum area ratio is 3.     

细粒煤重介质离心分选脱硫试验研究

在重介质条件下利用Falcon离心重力分选系统,研究了-500μm不同窄粒级南桐细粒煤的脱硫降灰效果.采用可燃体回收率、脱灰率、脱硫率、脱硫效率4个指标,对比分析了Falcon重介离心分选和常规浮选对南桐细粒高硫煤各粒级的分选效果,结果表明:对于-500μm细粒级煤,脱灰率低于常规浮选,而其余3个指标均高于浮选.125μm是分选效果的显著分界粒度,500～125μm粒级煤的脱硫率、脱灰率高于浮选,而可燃体回收率低于浮选.-125μm粒级煤的脱硫率、脱灰率低于浮选,而可燃体回收率高于浮选.     

新型柱浮选泡沫输送装置及固液两相流动特性

针对高含气率、高黏性柱浮选泡沫输送的需要,设计了一种新型柱浮选泡沫输送装置,并进行了固液两相流动特性模拟.结果表明,漩涡多靠近叶片工作面,其方向与叶轮旋转方向相反;叶轮内各流道压力分布较为均匀,叶轮中心区域为低压力区;颗粒直径越大,叶片工作面和轮缘处分布的颗粒越多,磨损程度越重;颗粒浓度越大,流体的全速度越高,叶轮出口附近处颗粒速度梯度越大,叶轮受局部磨损程度越重.基于数值模拟的优化设计结果表明,采用后倾叶片、扩大出料管径和增加出料管数量,有利于改善输送效果.     

A comparison of anionic and cationic flotation of a siliceous phosphate rock in a column flotation cell

Flotation performance of a de-slimed (-150 + 53 μm)Jordanian siliceous phosphate was evaluated in a batch laboratory flotation column 100 cm high and 5 cm inside diameter. The collector used during anionic flotation was sodium oleate while an amine acetate (AEROMINE 3100C) was used for cationic flotation. Flotation comparison at different collector dosage, superficial gas velocity, and frother concentration showed that the maximum difference in performance between cationic and anionic flotation was obtained with these flotation parameters: 30 × 10 6 (mg/L) frother concentration, 250 g/tcollector concentration, and 3.4 cm/s superficial gas velocity. At these operating conditions amine (cationic) flotation gave 7% higher flotation recovery, a 6% cleaner concentrate grade, and was 6% more efficient at removing silica.     

加压溶气气浮法处理矿井水中悬浮物的研究

对加压溶气气浮法处理矿井水中悬浮物的处理效果进行了试验研究。研究结果表明,当悬浮物浓度小于500mg L时,反应时间为6-8min,溶气压力为0.30MPa,回流比为10-15%,分离负荷为5-7m3 m2·h,投加0.1-0.3mg L的表面添加剂后,处理后的水质可满足工业回用水要求。该工艺去除效率高,运行管理方便,占地少,投资省,投药量少,是一种经济实用可行的处理工艺。     

Physical properties and ?lter cake structure of ?ne clean coal from flotation简

In order to improve the dewatering rate and the effect of fine clean coal (FCC), the advanced method of fine coal (−0.5 mm) dewatering and the correlated basic theory were investigated in this study. It was found that the dewatering by sleeve type press filter was an efficient way of FCC dewatering. On the other hand, the results also proved that particle size distribution, volatile matter, ash content, pore size distribution and specific surface area of coal particles of FCC samples, as well as viscosity and density of FCC slurry, were important parameters in determining the process of efficient dewatering. Especially, wet mass to dry mass, specific resistance of average mass, compressibility factor and microstructure of filter cake explained the reasons and mechanisms of fine clean coal efficient dewatering.     

A single-phase turbulent flow numerical simulation of a cyclonic-static micro bubble flotation column

Improved fluid dynamics can enhance the separation efficiency of flotation methods.A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-stat...     

Parametric study of electrostatic separation of South African fine coal

The fact that water requirements are a major problem for present and future developments in material beneficiation, and the construction of a new power plant in South Africa, forms the basis for the utilization of a Rotary Triboelectrostatic Separator (RTS) for beneficiation of South African pulverized coal. The cleaning potential of Majuba and Koorfontein coal was first evaluated using kinetic froth flotation tests on the -177μm coal fraction. The RTS tests were conducted under varied process parameters. Parameters such as applied separating voltage, air injection velocity, particle feed rate and splitter position were investigated. Two stage separation results show that the RTS reduced Majuba coal initially containing about 30% ash to a clean product of 14.30%, or 19.46%, ash at a combustible recovery of 15.10%, or 53.02%, respectively. Similar separation performance was also achieved with the Koorfontein coal. The mineral and organic compositions in the feed, after single stage and after the second stage separations were characterized using X-ray diffraction analysis. The results show a better separation for the second stage coal products.     

AN EFFICIENT ACTIVATIOR ON FLOTATION OF FINE ANTIMONY OXIDE

Recoveryoffineantimonyoxidewithfrothflotationisoneofthemostdifficultproblems.Theoxidemineralisnotonlytobeslimedeasily,butalsotendstoformcolloidinwatersolution,andtoitshydrolysis,onitssurface,thereexistsSbO,inalkalinesolutionandSbO inacidicsolution.UPtonow,traditionalgravityconcentrationmethodhasbeenuniversallyusedtorecoverantimonyoxide.Nowsomeantimonymillsstilluseshakingtabletechnique,buttherecoveryisonlyabout20%.Inflotationsystem,thecolloidofantimonyoxideiseasilyadheredonthesurfaceofsilicif…     

用大地电磁频谱测量法探测煤矿区陷落柱

根据大地电磁频谱测量法的基本原理和特点,确定了相关的探测区大地电阻率模型,校正系数,将所得频率的标定直接转换为探测深度的刻度.通过探测实例,说明了大地电磁谱测量法在煤矿区探测陷落柱和识别煤层等的应用效果和应用前景.     

水质硬度对煤泥浮选的影响

用循环水和自来水作为浮选试验用水,用石膏和硫酸钾作为水质调整剂,通过实验室和工业试验,研究水质硬度对煤泥浮选的影响．结果表明：水质硬度是影响煤和黏土颗粒之间分散稳定性的关键因素．随着水质硬度的升高,浮选精煤灰分提高了1％～2％,但精煤产率没有明显变化．水质硬度小于35。DH时,水质硬度越高,煤和黏土颗粒之间的凝聚作用越强,精煤灰分越高;水质硬度大于35°DH时,这种凝聚作用不再增强,精煤灰分也不再提高．     

Coal flotation using wash oil as a new type of collector

The use of wash oil as a coal collector is proposed to overcome the disadvantages of regular collectors in coal slime flotation. These disadvantages include high price, limited sources and high consumption. The effect of additives on flotation was studied and an innovative "one rough separation-one cleaning separation" flotation technology was developed. The experimental results show that the clean coal ash content decreases by about 1.36% and the clean coal yield declines by around 10% with the application of the depressant. There is an increase of 3.76% in the yield of clean coal and a decrease of 0.40% in the ash content caused by utilizing a dispersant. An ultimate product having an ash content of 10.78% and yield of 70.12% can be attained using a combination of dispersant and depressant. The use of this new technology decreases the ash content by 1.21%, decreases the yield by 2.80% and an increases the coal flotation perfect index by 2.03%. Compared to common flotation, the utilization of the new technology reduces ash by 0.17%, increases yield by 5.3% and increases perfect index by 4.18%.