对于GB/T 15716-2005《煤用筛分设备工艺性能评定方法》中临近粒度物含量的质疑

根据传统难筛粒含量的基本概念,对比分析了GB/T 15716-2005《煤用筛分设备工艺性能评定方法》中,用临近粒度物含量作为工艺效果评定指标的不妥之处;以精煤泥弧形筛使用和不使用击打器的对比试验案例,对两者之间的差异进行了分析比较;同时引用该标准中的数据,揭示了临近粒度物含量并未随分配粒度增大而减小的事实。     

0.15mm筛缝精煤泥弧形筛工艺指标分析

凤凰台选煤厂对引进国外加工技术和材质的精煤泥弧形筛进行了工业性试验,不锈钢筛条筛缝为0.15 mm,在采用气动式击打器和单位处理量为4.3 t/(h·m~2)的条件下,获得了多项工艺指标,其中按指定粒度0.15 mm所计算的筛分效率为82.40%,使得进入浮选作业的煤泥量比原采用0.4 mm筛缝时减少了近一半。     

煤泥二次浮选、精煤泥两段回收流程在梗阳选煤厂的应用

根据生产系统检测的数据,分析并评述了梗阳选煤厂煤泥二次浮选、精煤泥两段回收流程中粒度控制、煤泥粗选、粗精煤泥脱水回收、煤泥部分精选四个主要作业的效果;该流程整体工艺分选指标效果好,能有效回收煤炭资源,解决浮选精煤灰分普遍偏高的问题。     

振动击打弧形筛在斜沟煤矿选煤厂的应用

针对斜沟煤矿选煤厂弧形筛脱水效率差,混煤水分偏高的问题,通过在筛面上加装击打装置和振动电机对弧形筛进行改造,并对改造后的应用效果和经济效益进行分析。结果表明,弧形筛上安装的击打器能适时击打筛网,及时清除筛网缝隙内的细粒物料。弧形筛上安装的振动电机能使筛网产生一定频率的振动,实现筛网上物料的均匀分布和输送通畅,顺利完成弧形筛的脱水、脱泥和分级作业。改造完成后,振动击打弧形筛脱水效率由32%提高至55.5%,粗煤泥水分由14%降至10%,混煤水分降低了0.2%,发热量增加了0.48 MJ/kg,降低了分选成本,提高了混煤综合产率,每年可节省费用372万元。     

煤泥浮选最佳粒度的探讨

利用大量的生产和实验资料 ,分析了煤泥粒度对浮选的影响、粗煤泥分选的有效设备及细煤泥的分选方法。提出煤泥浮选最佳粒度范围为 0 .2 5～ 0 .0 74mm;+ 0 .2 5mm的煤泥应采用加工费用低的重选设备 ;- 0 .0 74mm细煤泥应根据煤泥特性采用更有效的处理方法     

两种粗精煤泥回收工艺的分析与比较

对临涣选煤厂的两套粗精煤泥回收工艺流程,即弧形筛—煤泥离心机组合和水力旋流器—弧形筛—煤泥离心机组合,按同一粒度组成的入料用各作业的粒度分配率进行了数质量计算,结果表明,前者更适用于粗精煤泥回收工艺。     

选煤厂煤泥压滤工艺优化及成本控制研究

分析了朱集东选煤厂煤泥压滤生产过程中的试验数据,结合煤泥灰分、入料粒度及浓度、聚合氯化铝、过滤压力等因素对压滤周期的影响,根据优化的生产工艺参数,构建了吨煤泥成本控制模型,有效降低了生产消耗,实现了压滤生产成本最小化。     

龙固选煤厂煤泥浮选试验研究

论述了煤泥浮选原理。通过小筛分试验和分步释放试验对煤泥性质进行分析,说明入浮原煤平均粒度较粗,生产中要控制入浮粒度。通过对煤泥初步探索浮选试验和正交试验的研究,确定了最佳浮选条件为：捕收剂1330 g/t,起泡剂266 g/t,质量浓度60 g/L,得到精煤产率75.06%,精煤灰分8.70%,浮选完善指标59.03%。     

煤泥分选技术现状分析及展望

分析了国内外粗煤泥、细煤泥分选技术特征,阐述了主要设备的工作原理和发展现状,提出各分选技术的最佳使用条件。粗煤泥分选设备主要有煤泥重介质旋流器、螺旋分选机、水介质旋流器组、干扰床分选机,其中煤泥重介质旋流器发展迅速,有效降低了重介选煤的分选下限。细煤泥分选技术核心设备是浮选机,浮选柱对细粒物料有更好的分选效果。煤泥分选工艺主要有煤泥一级浮选、精煤泥一段回收、浮选精煤精选、煤泥分级浮选流程。最后提出粗煤泥分选技术应优化原煤分选工艺,进行不同工艺组合,提高综合分选效率。细煤泥分选应改进浮选设备以适应更宽的入料粒度范围,结合浮选准备作业和浓缩压滤作业,优化浮选工艺,设计出一套指标先进、成本低的高效细煤泥分选工艺。     

临涣选煤厂煤泥过滤性能的实验研究

针对临涣选煤厂煤泥粒度较细、泥化现象严重的特点,实验确定了最佳过滤方案:即选择滤腔深度约40mm,入料压力为0.8MPa,压榨压力为1.2~1.5MPa,并加入LAC2005-A药剂后过滤,可取得最好的过滤效果。     

Protein and lipid films at equilibrium at air-water interface

The surface activity of β-casein, caseinate, and a whey protein isolate in aqueous solutions has been investigated over a range of protein concentrations (1·10⁻⁵ to 5% w/w) at pH 5 and 7. The surface pressure data were determined by the Wilhelmy plate method. Surface pressure data at low protein concentration indicate a low surface activity that rises to a plateau as the monolayer is saturated at higher protein concentrations. The protein concentration and the surface pressure at the plateau depend on the pH and the type of protein in the aqueous phase. Protein-monoglyceride interactions were investigated by spreading an insoluble monoglyceride (monopalmitin, monoolein, or monolaurin) on a film of protein previously adsorbed on the interface at equilibrium. The existence of protein-monoglyceride interactions depends on the interfacial composition and on the protein/monoglyceride ratio. The surface activity of mixed protein-monopalmitin and protein-monoolein films is determined by the lipid as the surface pressure of the mixed film is the same as the monoglyceride equilibrium spreading pressure, and the monolayer is not saturated by the protein. However, the protein determines the surface activity of mixed protein-monopalmitin and protein-monoolein films as the protein saturates the monolayer. For protein and monolaurin mixed films, protein determines the surface activity over the range of protein-monolaurin compositions due to monolaurin dissolution in the bulk aqueous phase.     

Looking at Heterogeneous Catalysis at Atmospheric Pressure Using Tunnel Vision

This paper addresses the “pressure gap” between traditional surface science experiments and catalysis under practical conditions. We review high-pressure, microflow experiments at elevated temperatures during the catalytic oxidation of CO. Using a specially constructed “Reactor-STM” we simultaneously determine the surface structure of a model catalyst by scanning tunneling microscopy and the reaction kinetics by online mass spectrometry. For both Pt(110) and Pd(100) we find that under O₂-rich conditions surface oxides are formed on the otherwise metallic surfaces. The presence of the oxide is correlated with a superior catalytic activity. Whereas the reaction on the metal surfaces shows traditional Langmuir–Hinshelwood kinetics, the reaction on the oxides follows the Mars-Van Krevelen oxidation–reduction mechanism, as we conclude from the reaction kinetics and the reaction-induced roughening of the surface. We emphasize that in addition to a pressure gap there can also be a temperature gap, requiring experiments to be performed not only at high pressures but also at sufficiently high temperatures.     

爱护从"皮毛"开始

谁都希望自家的宠物皮毛干净亮泽,要做到这点,只靠洗澡是远远不够的。平时注意对狗狗皮毛的梳理和护理,不仅可以保护宠物的皮毛,还可以加深与宠物的感情。护理狗狗的体毛最基本的方法是梳理。每天对爱犬体毛的梳理,既可以起到去除体毛里的脏物、刺激皮肤、促进血液循环的作用,也能使狗狗的体毛更加整齐。     

看着我

意大利艺术家布鲁诺用精湛的技艺和独特的绘画方式为木头注入灵魂,传神的表情和细腻的肢体线条甚至比真人还美。走进意大利木雕艺术家布鲁诺·沃尔普思（Bruno Waipoth）的工作室,迎面扑来木屑的清香,屋顶上的大天窗把工作室照得透亮。几位全身涂得粉白的＂模特＂或坐或站,似在为艺术杂志拍摄封面,却见不着摄影师的踪影。它们就是布鲁诺闻名世界的木雕作品,传神的表情和细腻的肢体线条像极了真人,甚至比真人还美。正是这些惊人的作品,让布鲁诺将木雕艺术推向另一个境界。     

Copolymers at Interfaces

Abstract

New phosphorous and chlorine containing oligomeric and polymeric products are synthesized and their potential as inhibitors of burning for polymeric materials demonstrated.