南桐细粒煤离心重力分选脱硫试验研究

分析了南桐细粒煤的硫分组成及其分布规律,通过对其煤岩特性研究,得出南桐细粒煤中黄铁矿嵌布特性及其物理法脱硫的可行性,通过在Falcon离心重力场中的分选脱硫试验,研究了微细粒级煤在离心重力场中的分选行为,以及不同窄粒度级的脱硫效果.结果表明:对>0.045mm煤炭,Falcon离心分选机可以有效分选脱硫,而由于微细粒在分选过程中随水流进入溢流量加大,Falcon离心机对<0.045 mm微细粒级煤炭的分选效果较差.     

细粒煤在Falcon分选机中的运动特性及其脱硫研究

简述了Falcon离心重力分选机的特点及工作原理,通过细颗粒在Falcon离心重力场中的受力分析和沉降末速的计算,得出了颗粒沉降时间与离心加速度的关系,结果表明：颗粒的离心加速度越大、固体颗粒与介质的密度差越大、颗粒直径越大,则沉降时间越短.通过对转筒内流膜运动特性分析,研究了处于转筒内不同流膜微层中的颗粒切向速度的变化规律,结果表明：流膜内各微层的切向流速沿径向递增.分析对比了Falcon离心分选和浮选分步释放试验脱硫效果,结果表明了细粒煤在离心重力场中的全硫脱除率要比基于颗粒表面性质分选的浮选过程平均高5%左右.     

极细粒煤选择性双向絮凝脱硫降灰实验研究

介绍了选择性双向絮凝分选原理，根据该原理研究了极细粒煤泥深度脱硫降灰技术，分析了煤样粒度、非极性油与分散剂用量对选择性双向絮凝分选效果的影响，结果表明：使用该技术对极细粒煤泥分选后，可使其灰分降到1％以下，可燃体回收率达90％以上(最高值达94．57％)，产率达69．77％．脱硫时，可将硫分从3％降到0．4％以下，而且脱硫的同时可以脱灰。     

基于BPMA预测的特低灰煤浮选制备效果

特低灰煤的制备对于煤炭提质增效与“碳减排”具有重要现实意义.本文通过工业分析、粒度组成、X射线衍射(XRD)及X射线荧光光谱(XRF)考察了长平选煤厂煤泥性质，借助工艺矿物学自动分析仪(BPMA)对脱泥后样品中灰分的嵌布特征及解离效果进行了分析，发现解离前矿样中的灰分主要为内灰，占有率为8.13%,碳质与脉石矿物的连生非常密切，解离后内灰的占有率为4.68%,脉石矿物多以单体形式存在，即特低灰煤的理想灰分为4.68%.利用常规浮选和絮团浮选验证了BPMA预测灰分的可靠性，并采用接触角、Zeta电位分布和扫描电镜(SEM-EDS)分析了细泥罩盖机理和聚合氯化铝(PAC)的作用机理.结果表明：常规浮选制备所得特低灰煤的灰分为5.01%,与理想值最接近，但是可燃体回收率较低，而絮团浮选制备所得特低灰煤的灰分为5.48%,可燃体回收率达86.30%.PAC在浮选试验中的添加增大了样品接触角，使样品疏水性增强，提高了精煤的选择性，同时通过电中和作用使高岭石发生团聚，降低了矿物质在煤表面的罩盖，使产品灰分降低.     

流化床煤颗粒分级试验研究

为了解决细煤粉污染焦炭及焦油的品质问题,基于气固流态化原理,搭建TG-100型悬浮式涡流筛分中试装置,进行煤颗粒的粒度分级试验研究.以500μm为目标粒径,考察不同流化风速对煤颗粒分级效果,监测分级前后煤颗粒的水分变化.结果表明:随着流化风速的提高,参与流化的颗粒直径不断增大,煤颗粒的干燥效果不断提高,当入口风速为55 m/s(流化风速为1.84m/s)时,分级效果最佳,细煤颗粒中500μm以下粒级含量高达99.7%,粗煤颗粒中500μm以下粒子含量仅为28.7%,分级后水分降低了44.58%,表明煤颗粒分级过程还具有一定的干燥效果.     

煤粉永磁强磁滤器的设计及磁场特性

针对传统永磁磁选设备磁场强度低的不足和微粉煤磁选脱硫的需要,基于多面挤压和磁铠装技术,研制出一种新型煤粉永磁磁滤器,并进行磁场特性模拟和分选试验研究.结果表明:软铁厚度为4mm,环径比为10:3时,磁场强度最高为3.298T,挤压导磁和铠装聚磁效果显著,磁场强度随着软铁与磁体厚度比的增加先增后减,最佳比例关系为1:5.环径比对磁场强度变化影响很小.磁场强度随软铁伸出分选空间长度的增加而增大,但趋势渐缓,软铁伸出0.5mm时,导磁效果明显.磁选脱硫和降灰率随粒度减小而增大,不同粒级煤粉的脱硫和降灰率随精煤产率增加而减小,0.074～0.15mm粒级的精煤产率为95.61%,脱硫和脱灰率分别达44%和43%.     

中低品位铝土矿浮选柱短流程分选研究

我国铝土矿绝大多数为中低铝硅比的一水硬铝石型,矿物嵌布粒度细,分选困难.在分析铝土矿矿石性质的基础上,利用旋流-静态微泡浮选柱对中低品位铝土矿进行分选,考察了捕收剂用量、循环压力、处理量等因素对浮选效果的影响.研究结果表明:铝土矿易泥化,微细粒级含量高,其有效分选是关键;随着捕收剂用量、循环泵压力、处理量的增大,氧化铝回收率增加、精矿铝硅比下降;当捕收剂用量1000g/t,循环泵压力0.17MPa,处理量4.0t/(m2.h)时,精矿铝硅比8.02～8.13,氧化铝回收率88.77%～90.01%.采用"一粗一精"两段浮选柱分选可以完成浮选机"一粗两精两扫"五段分选作业,分选流程短,工艺简洁.     

超声波预处理对稀缺难浮煤浮选的作用

为提高稀缺难浮煤的浮选效果,引入超声波对稀缺难浮煤矿浆进行预处理,利用Setar-amC80Ⅱ型微量热仪、DCAT21型接触角测定仪和752型可见光光度计研究了超声波预处理后的矿浆的浮选过程.结果表明:当超声波频率为40kHz,矿浆预处理4min后浮选,精煤灰分大致相同时,精煤产率、浮选完善指标和可燃体回收率分别比未经预处理的提高了19.47%,18.80%和24.14%.预处理促进了煤粒与矸石的解离,煤泥的粒度变细;超声波预处理使煤泥的疏水性增强,不同粒级煤泥与水的润湿热以及对煤油的吸附量均有不同程度的降低,煤与水的接触角有不同程度的升高.超声波预处理能提高稀缺难浮煤的浮选效果.     

极细粒煤泥分选新方法：选择性絮凝

采用选择性絮凝剂,对煤中可燃体与非可燃体进行分离,称为选择性絮 凝。笔者对大屯、八一、大武口等5个选煤厂和煤矿的极细粒煤泥进行了大量的 试验,证明该法可作为极细粒煤泥的分选方法,并具有较好的选择性。经分选, 一般精煤灰分为12-13％,最低为5.73％,可燃体回收率达90％以上,两产品 之间灰分差一般在50％左右,效果较好。因此,是一种较有前途的方法,可用 在分级浮选中,作为极细粒煤泥的分选方法。     

煤泥分级浮选工艺的研究

为了解决煤泥混合浮选工艺中分选粒度范围过宽、高灰细泥夹带污染精煤,导致浮选精煤灰分高、尾煤灰分低,严重影响精煤产品质量的问题,采用正交试验、小筛分、分步释放浮选实验方法,对影响浮选效果的因素进行深入的探讨,提出了分级浮选工艺：用分级旋流器组进行浮选入料粗、细煤泥分级,〈0.125mm细煤泥采用新型旋流微泡浮选柱-快速双隔膜压滤机处理,0.5～0.125 mm粗煤泥采用原有的浮选机-过滤机处理,实现粗、细煤泥高精度分选和高效脱水.结果表明：应用分级浮选工艺,浮选精煤灰分下降了1.08%,尾煤灰分提高了9.51%,精煤回收率提高了0.73%.     

Experimental Research on Desulfurization of Fine Coal Using an Enhanced Centrifugal Gravity Separator

A desulphurization experimental study under the effects of compounding physical force fields has been described for 〈 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of experiments was conducted to evaluate the effects of individual operating variables and their interactions on desulfurization of fine coal using an enhanced centrifugal gravity separator. A model describing the relation between desulphurization efficiency of pyrite sulfur and different operating variables has been designed. The interactions between different factors on the pyrite sulfur desulphurization efficiency have been analysed. The optimal test conditions for desulfarization are extracted from the Design-Expert 6.0 software. Finally, the pointed out. advantage of centrifugal gravity separation for fine coal is pointed out.     

Metals Recovery from Fine Printed Circuit Boards Using Falcon SB Concentrator

Physical methods show great potential and advantages on comprehensive reutilization of waste printed circuit boards （PCBs） because of lower investment and operation cost, higher efficiency and environment friendliness. However, metals contained in fine fraction of PCBs cannot be recovered effectively by conventional equipments such as high tension electrostatic separator or shaking table. In the paper, this conundrum was resolved successfully with the enhanced Falcon SB concentrator. The separation mechanism of Falcon SB concentrator was analyzed and main factors affecting separation efficiency such as magnitude of rotation frequency of bowl, water counter pressure and slurry concentration of feed were studied and interaction of factors above also were investigated using Design-Expert software. Experiment results show that complete liberation degree and great difference of density between metals and nonmetals are suitable to recover metals from -74μm PCBs using enhanced Falcon SB concentrator and 80.77 % integration efficiency can be achieved when slurry concentration of feed is 40 g/L with the water counter pressure of 0.01 MPa and rotation frequency of 50 Hz.     

微粉煤的电性质及摩擦带电研究

为了提高煤的摩擦电选脱硫降灰效率,应用同心圆筒测量法研究了煤及伴生矿物颗粒的比电阻、应用开尔文探针法研究了煤及伴生矿物与不锈钢的接触电位差、应用法拉第桶测量了煤及伴生矿物的摩擦带电荷质比.结果表明：净煤和高岭石与不锈钢间的接触电位差为正值,在与不锈钢摩擦时带正电,而黄铁矿和石英与不锈钢间的接触电位差为负值,在与不锈钢摩擦时带负电;小于1.6 g/cm^3各密度级和大于1.6 g/cm^3各密度级摩擦带电符号相反.温度升高或湿度降低使得颗粒的电阻率升高,有利于提高颗粒的摩擦带电量和分选效率.     

电解还原法强化高硫煤浮选脱硫机理研究

采用电解还原法对高硫煤预处理后，使煤表面的含氧官能团减少，疏水性增强；同时，黄铁矿表面初始氧化产物如单质硫和多硫化物被还原，亲水性增强．煤粒和黄铁矿颗粒两者的表面性质向相反的方向改性，从而实现强化浮选分离的目的，理论上分析了煤和黄铁矿表面的改性机理，并通过试验验证了电解还原法强化浮选能够明显地降低浮选精煤中的硫分．对不同煤样的浮选结果表明：北宿煤样的黄铁矿脱除率可达89％以上。     

采用Design-Expert设计进行优化Falcon分选试验

采用Design—Expert6．0软件对Falcon离心重力分选脱硫试验进行了方案设计和试验结果分析;讨论了脱硫试验效果的评价方法,给出了综合脱硫效率与试验影响因素之间的定量关系模型,给出了综合脱硫效率的残差分布以及不同操作变量之间的综合脱硫效率等值线和三维关系;利用Design—Expert6．0对Falcon分选试验条件进行了优化,获得了最佳综合脱硫效率的操作指标．     

Falcon选矿机的分选机理及其应用

Falcon选矿机是一种新型的离心分选机．为研究其分选机理，以Falcon SB离心分选机为例，建立了球形颗粒在离心分选机分层区和分选区的动力学方程．分析结果表明，在Falcon SB分层区，高强度离心加速度是实现微细颗粒快速沉降的关键因素；分选区内独特的流态化反冲水形成流态化床层，使得微细高密度颗粒穿过床层沉积到来复圈槽中，而低密度颗粒所受的离心力较小，加上难以克服反冲水的作用而进入尾矿，从而实现了不同密度微细颗粒的有效分选．采用Falcon SB40选矿机分选一0．074mm电路板的试验结果表明：在入料浓度为40g／L，给料速度为160L／h，反冲水压力为0．01MPa，滚筒旋转频率为50Hz时，一次分选获得金属富集体的品位为76．89％，回收率82．19％，综合效率80．77％．     

Coal petrology characteristics of middlings from Qianjiaying fat coal mine

The objective of this paper is to evaluate the coal petrology characteristics of slack middlings (13–0.5 mm) of dense media separation and flotation middlings from Qianjiaying fat coal preparation plant. Phase composition, macerals distribution, microlithotype and mineral occurrence of the two middlings were studied by XRD analysis and polarized light microscopy observation. Macerals distribution and wettability of the float-and-sink products separated from the middlings after grinding was investigated to determine the liberation degree. Studies show that there are more vitrinite and mineral, but less inertinite in slack middlings than in flotation middlings. Macerals associated with mineral in slack middlings is 69.85%, by volume, which is 17.86% higher than that in flotation middlings. Minerals in slack middlings are dominated by pyrite and clay, which are disseminated with the diameter less than 2 μm. The main mineral in flotation middlings is clay with size range of 2–20 μm. Single macerals in the slack middlings are difficult to liberate due to the fine-grained minerals. After grinding, macerals associated with minerals in the slack middlings decrease to 46.73%, by volume, which is higher than in flotation middlings by 25.89%, by volume. For slack middlings with poor liberation degree, density fractions below 1.8 g/cm³ is hydrophobic with contact angle above 71.5°. For the well liberated flotation middlings, there is significant wettability difference among the float-and-sink products. This research is the theoretical basis to realize re-separation of middlings.     

室式分离机转鼓结构的改进与液流分析

介绍了室式分离机的转鼓结构及工作过程．为提高这种机器的分离效率,重点对室式分离机的转鼓结构做了改进．通过对室式分离机改进型转鼓中悬浮液的流动速度进行分析,为实现不停机自动排渣提供理论基础．     

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.