玻璃水配制磁悬液的可行性研究

磁粉检测湿法是利用磁粉和分散剂按一定比例混合而成的磁悬液,喷洒到磁化工件的表面来检测工件的缺陷。按分散剂分为:水磁悬液和油磁悬液常规配比磁悬液的载体通常是水基或是油基。水基配比的磁悬液在冬季会结冰,油基配比的磁悬液在冬季黏稠比也会上升,造成磁悬液流动性变低,影响检测灵敏度,容易造成漏检。因此,冬季无法使用水基或油基磁悬液进行室外磁粉检测。     

全尾砂絮凝沉降特性实验研究

采用均匀法进行室内实验设计,研究絮凝剂单耗、絮凝剂溶液浓度和给料浓度三因素对固液分离技术中沉降速度和沉降浓度的影响.对实验数据进行回归分析后认为,各因素对沉降速度的影响程度从大到小为:给料浓度 > 絮凝剂单耗 > 絮凝剂溶液浓度.沉降速度与絮凝剂单耗、絮凝剂溶液浓度正相关,与给料浓度负相关;对沉降浆体浓度影响程度从大到小为:给料浓度 > 絮凝剂单耗 > 絮凝剂溶液浓度.沉降浓度与絮凝剂单耗、给料浓度正相关,与絮凝剂溶液浓度基本无关.利用非线性规划寻找最优配比,预测值与验证实验的实测值误差小于8%.推荐的深锥浓密机运行参数为絮凝剂单耗5 g·t^-1,絮凝剂溶液浓度0.05%,给料浓度5.233%.     

安徽某铁精粉细度控制因素研究

以安徽某铁矿选矿厂的生产数据为依据,分析了铁精粉细度合格率与选矿过程中自磨浓度、球磨浓度、溢流浓度以及铁矿石品位之间的关系;利用正交试验分析了对铁精粉细度影响的主次因素。试验发现,铁精粉细度合格率均随着自磨浓度、球磨浓度、溢流浓度以及铁矿石品位增大而减小,在这些因素中对铁精粉细度影响最大的是溢流浓度、球磨浓度,其次是自磨浓度和铁矿石品位。     

400kA系列铝电解槽区域氧化铝浓度时空分布研究

以400kA系列铝电解槽为试验槽研究了大型预焙铝电解槽区域氧化铝浓度分布情况。结果表明,铝电解槽不同区域的氧化铝浓度在不同的时间点均发生较大的波动,越靠近两端头位置处的氧化铝浓度的波动性越大;氧化铝浓度呈现先减少后增加的趋势,在靠近两端头位置氧化铝浓度出现最大值,在槽中间位置氧化铝浓度出现最小值;进电侧和出电侧对称分布位置上的氧化铝浓度分布曲线具有相似性,出电侧氧化铝浓度总体高于进电侧氧化铝浓度;氧化铝浓度保持在1.00%~2.00%之间的时间分布比例大,实现了区域低氧化铝浓度控制。     

钒离子浓度和硫酸浓度对负极电解液电化学性能的影响

为了改善负极电解液的电化学活性,提高其能量密度,研究了钒离子浓度和硫酸浓度对电解液粘度、电导率和电化学活性的影响。结果表明,钒离子浓度和硫酸浓度通过改变电解液中的氢离子浓度和钒离子的聚集状态而影响电解液的粘度、电导率和电化学活性。负极电解液的粘度随着钒离子浓度和硫酸浓度的增加而增大;电导率随着硫酸浓度的增加而增大,但增加钒离子浓度降低溶液电导率。合适的硫酸浓度可以改善电解液的电化学活性,而提高钒离子浓度抑制了电解液传质和电荷传递过程。当钒离子浓度为2.0 mol/L,硫酸浓度为2.0 mol/L时,电解液的电化学活性和可逆性最好,其传质速率为(1.39～2.25)×10~(-7) cm~2/s,电荷传递速率为1.74×10~(-5) cm/s。     

硫代硫酸钠浸出贵州卡林型金矿

研究了用硫代硫酸钠从贵州卡林型金矿中浸出金,考察了Na2S2O3浓度、乙二胺浓度、Cu2+浓度、Na2SO3浓度和溶液pH值等不同因素对金浸出率的影响.试验结果表明:Na2S2O3浓度为0.35 mol/L,乙二胺浓度为0.1 mol/L,Cu2+浓度为0.075 mol/L,Na2SO3浓度为0.1 mol/L,溶液...     

Phanerochaete chrysosporium降解碳质金矿中元素碳高关联度变量的筛选

采用Plackett-Burman设计法对Phanerochaete chrysosporium降解碳质金矿中元素碳的高关联度变量进行筛选。通过前期的单因素试验确定影响真菌降解碳质物的8个变量,分别为愈创木酚浓度、糊精浓度、吐温-80浓度、草酸浓度、过氧化氢浓度、矿浆浓度、真菌浓度和作用时间。通过两水平的Plackett-Burman设计法确定影响真菌降解元素碳的高关联度变量,分别为愈创木酚浓度、草酸浓度和矿浆浓度。愈创木酚是一种诱导剂。低浓度时,愈创木酚通过提高酶活性和诱导一些酶产生,促进元素碳的降解。高浓度时,酶产生和酶活性受抑制,不利于元素碳的降解。草酸通过调节降解体系的pH值影响菌体生长及酶活性。矿浆浓度会影响元素碳和真菌的有效接触面积以及降解体系的剪切力和传质效率。     

原地浸矿工艺浸出液浓度控制技术研究

针对目前离子型稀土矿山生产过程中普遍存在的浸出液浓度低、基建成本及动力费用高等问题,通过开展浸矿剂浓度对浸出液浓度的影响、注液强度对浸出液浓度的影响、渗透率对浸出液浓度的影响、整合各项影响因素、参数,有效控制浸出液浓度等一系列研究,指导离子型稀土低耗高效开采。     

正硅酸乙酯包覆铝银粉抗蚀性的研究及表征

采用溶胶-凝胶法制备了正硅酸乙酯(TEOS)包覆的铝粉颜料。通过设计正交试验研究了反应时间、反应温度、催化剂浓度、蒸馏水浓度及TEOS浓度对包覆铝粉耐酸效率的影响,得出最佳工艺方案并对包覆产物进行了表征。极差分析结果表明:各反应条件对包覆铝粉耐酸效率影响的主次顺序为:反应时间反应温度TEOS浓度蒸馏水浓度氨水浓度。最佳工艺方案为反应时间4 h,反应温度35℃,TEOS浓度63.4%,蒸馏水浓度29.3%,氨水浓度35.4%。包覆粉末SEM、EDS、FT-IR及XRD结果表明铝粉表面成功包覆了一层二氧化硅包覆膜。     

直筒式脉冲电旋风除尘器内颗粒浓度分布实验研究

在脉冲电旋风除尘器研究的基础上,对直筒式脉冲电旋风除尘器内的颗粒浓度场进行测试分析,得出在一定入口风速、工作电压、入口粉尘浓度下除尘器内颗粒浓度分布规律及实测回归方程;进行不同供电方式下除尘器内颗粒浓度分布对比实验,研究表明脉冲供电可有效地降低除尘器内粉尘浓度,使除尘器内粉尘浓度分布趋向均匀。     

连续式磁性颗粒去除器永磁分离机理及其影响分析

文章就连续式磁性颗粒去除器中磁性悬浮颗粒在磁场中受力分析，从而获得磁性悬浮颗粒最小捕获粒径的计算公式，进而指导试验，提出提高捕获率的措施．     

Preparation of Dysprosium Ferrite／Polyacrylamide Magnetic Composite Microsphere and Its Characterization

Researchofmagneticpolymermicrospherehasbeenstudiedsincethe 1970s .Themagneticpolymermicrospherecombinesthepropertyofmagneticparticlewiththatofmacromoleculeparticle .Itnotonlycanbeseparatedfromthemediumeasily ,butalsocanbesurface modifiedinorderthatthesurf…     

Analysis of Initiation of Sediment Suspension from Bed Load

A theoretical analysis of the initiation of sediment suspension is performed based on the concept of probability of suspension. The proposed condition for the initiation of sediment suspension from the top of the bed-load layer is comparable with most existing empirical relationships for large particle Reynolds numbers. The study shows that a constant Rouse parameter can be used as the critical condition for sediment suspension only for large dimensionless particle diameters. When the probability of suspension is taken to be an infinitesimal value (P = 10?7), the derived relationship of the Shields parameter and the particle Reynolds number is in good agreement with the updated Shields diagram.     

Particle size determination of a flocculated suspension using a light-scattering particle size analyzer

Microscopy is a useful and direct method for measuring the particle size of a suspension because, in addition to the particle size and size distribution, it provides visual detection of the shape and state of aggregation of the particles in the suspension. However, this method suffers from the shortcomings of being tedious and time consuming. In this study, a light-scattering particle size analyzer was used to determine the particle size and size distribution of a flocculated suspension. The sonication of the sample prior to and during measurement was found to be critical in ensuring that data are representative of the size distribution of the primary particles of the suspension. The light-scattering results were further confirmed by data generated using a polarized light microscope equipped with an image analyzer.     

Particle suspension in (air-agitated) pachuca tanks

Particle suspension is an important parameter in the design of an energy-efficient Pachuca tank. Unfortunately, very little attention has been focused on the suspension behavior of air-agitated Pachucas. In the present investigation, therefore, extensive experiments have been carried out in three laboratory-scale Pachuca tanks to examine the effect of design and operating parameters, as well as scale-up, on particle suspension. A mathematical model that combines the Bernoulli’s equation and the theory of transport of particles in the horizontal flow of a liquid has been developed to predict the critical gas velocity for particle suspension in Pachuca tanks. Some important results, crucial to the design and scale-up of Pachuca tanks, have emerged. Full-center-column (FCC) Pachuca tanks with a draft tube-to-tank diameter ratio (D _d/D_t) on the order of 0.1 are found to be energetically more efficient in suspending particles than free-air-lift (FAL) and stub-column (SC) Pachuca tanks. It is also observed that taller tanks require lower air flow rates for particle suspension than shallower tanks. Finally, it is explained why industrial Pachuca tanks operate at lower air velocities than laboratory-scale tanks.     

粉末粒度对注射粘结磁体性能的影响

实验分析了粉末粒度对制得的注射粘结磁体密度、取向度和磁性能的影响,得出了磁粉粒径太大和太小均不利于磁体磁性能的提高的结论．同时,通过搭配不同比例的粉末,可以提高磁体的装载量,从而达到提高磁性能的目的．     

Particle suspension in air-agitated pachuca tanks: Investigation of hysteresis and a novel split air injection technique

Particle suspension is an important parameter in the design of an energy-efficient Pachuca tank. The objectives of the present investigation are to (1) establish the phenomenon of hysteresis, (2) examine the effect of a novel split air injection technique on the critical velocity for particle suspension, and (3) determine the optimum state of suspension in full center column (FCC) Pachuca tanks. Extensive investigations have been carried out in three laboratory-scale Pachuca tanks with a maximum slurry density of 25 wt pct solids. Results that have a bearing on the design of energy-efficient Pachuca tanks have emerged. The magnitude of hysteresis in FCC Pachuca tanks is of the order of 20 pct, which is about 10 times less than in bubble columns. Split air injection, with 30 pct air injected into the annulus from the top and 70 pct air injected into the draft tube from the bottom, lowers the critical air velocity for particle suspension by 37 pct, with respect to bottom-blown Pachuca tanks.     

一种磁性内核锐钛型TiO2光催化剂的制备与研究

在水处理技术领域,TiO2光催化水处理技术因具有效率高、能耗低、适用范围广、反应条件温和等优点而被认为是最有前景的有机污染废水处理技术之一。直接应用TiO2悬浮体系处理污水要比基体负载固定TiO2体系有更高的处理效率,但是悬浮态的TiO2存在着回收困难的问题。对此,首先采用了共沉淀-水浴法制备了具有较好形貌的MnxZn1-xFe2O4软磁体颗粒,该软磁体颗粒能够在700℃以内保持良好的磁响应性;采用溶胶-凝胶法在颗粒上包覆SiO2中间层,得到了单分散球形的SiO2/MnxZn1-xFe2O4;采用水热法在其上包覆纳米锐钛型TiO2,最终得到了TiO2/SiO2/(MnxZn1-xFe2O4)磁性光催化剂,采用XRD、SEM、VSM等对其分析,结果表明:该催化剂呈单分散球形,粒径约在500 nm左右,具有明显的壳-核结构,磁性内核被SiO2严密包覆,锐钛型TiO2均匀负载其上,有灵敏的磁响应性。对毛用活性黄废水的降解实验证明了其较高的光催化活性。     

The Influence of Surface Chemistry on the Rheology and Flow of Flocculated Particulate Suspensions

Abstract

The role of the surface chemistry of particles in controlling the rheology of flocculated particulate suspensions is discussed. The case is developed for the measurement of the shear yield stress of a suspension of alumina particles and a theoretical interpretation of the yield stress is presented which is able to describe the effect of particle size distribution, solid loading, pH and hence, electrokinetics of the suspension. Scaling of the data to the maximum yield stress at a given volume fraction provides a means of removing particle size and volume fraction related effects and gives information as to the mode of failure in yielding of suspensions and the mode of action of molecular additives.     

磁性液体磁特性的Monte Carlo方法模拟研究

探讨了利用Monte Carlo方法模拟研究磁性液体磁性能的物理模型与计算方法;并通过对一个含有32个磁性颗粒三维体系相对磁化强度的模拟与计算,定量地分析了磁性液体浓度、温度及所分散磁性颗粒的大小对磁性液体磁性能的影响。