铜铅分离有机抑制剂FCLS的研究

研究了不同pH值和矿浆电位下有机抑制剂FCLS对黄铜矿和方铅矿的抑制作用。结果表明, 未添加FCLS时, 方铅矿和黄铜矿都具有良好的可浮性。FCLS存在时, 黄铜矿的浮选回收率略有降低, 方铅矿受到强烈的抑制。随着pH值增大, 矿浆电位逐渐降低, 矿浆电位对这两种矿物浮选回收率几乎没有影响。通过红外光谱研究了FCLS与矿物的作用机理, 结果表明, FCLS在方铅矿表面发生了强烈的吸附而在黄铜矿表面发生了微弱的吸附。     

Preparation of a tubular palladium membrane by photocatalytic deposition

A novel photocatalytic deposition method for the preparation of a thin tubular palladium membrane is presented in this paper. The membrane is prepared on a porous asymmetric TiO₂ support by photocatalytic reaction of palladium ion, followed by electroless plating. Gas permeation results show that the membrane exhibits increased hydrogen permeance with the increase of temperature. The hydrogen permeance and selectivity to nitrogen at 773 K are about 1.43×l0⁻⁶ mol m⁻² s⁻¹ Pa⁻¹ and 17, respectively, when the pressure in the feed side is 0.1 MPa. The activation energy of hydrogen permeation is 11.06 kJ/mol at the temperature range of 573–773 K.     

超临界CO2萃取丁香花蕾的工艺研究及对萃取物的GC—MS分析

本文应用超临界二氧化碳技术 ,研究了丁香花蕾的最佳萃取工艺。结合温度、压力、堆积密度、CO2 流量等因素对丁香花蕾提取物的萃出率的影响 ,采用四因素三水平的正交设计 ,得出丁香花蕾油萃取的最佳工艺条件为 :压力30MPa ,温度 4 5℃ ,CO2 流量 10L/h ,低堆积密度。作者还对萃取出的丁香花蕾油进行了GC—MS成分分析     

Design of a super-hydrophilic/super-oleophobic g-C3N4/Ti(OH)4/PFOA nanocomposite coated mesh as a smart nanofilter with robust anti-fouling properties for separation of oil and water emulsions

The design and development of efficient approaches for water–oil separation have had widespread interest. This study aimed to synthesize nanocomposites based on Ti(OH)₄ and g-C₃N₄ nanosheets (CN-NS) to show experimentally that the inclusion of Ti(OH)₄ nanoparticles of 9.2 nm size into CN-NS leads to an improved oil-water separation efficiency and anti-fouling performance. So, a novel, reusable, and recyclable super-hydrophilic/underwater super-oleophobic CN-NS/Ti(OH)₄ nanocomposite-coated stainless steel mesh was developed to separate oil-in-water emulsions. Super-wettability was obtained in the CN-NS/Ti(OH)₄ nanocomposite with WCA = 0° and UOCA = 154°, respectively, showing significant super-hydrophilicity and underwater super-oleophobicity. Surface hydrophilicity increased after anchoring Ti(OH)₄ on the CN-NS surface, resulting from oxygen-containing functional groups and consequently making defects on the mesh surface. Enhanced underwater oleophobicity of nanocomposite coated mesh is attributed to its higher surface roughness, which is a result of its micro-nano meter and mesoporous hierarchical structure. Moreover, the self-cleaning property of the as-prepared mesh was demonstrated by visible light irradiation on the contaminated mesh. In addition, perfluorooctanoic acid (PFOA) reduced energy in CN-NS/Ti(OH)₄/PFOA mesh, resulting in a super-hydrophilic/super-oleophobic mesh. The CN-NS/Ti(OH)₄/PFOA nanocomposite-coated filter was observed to separate water from a 1 wt% water-in-oil emulsion at 0.2 bar pressure with a filtration flux of 317.2 L m⁻² h⁻¹ and 95% separation efficiency.     

Model-based Scale Up of Solid Bowl Centrifuges Using Experimentally Determined Material Functions

The scale up of solid bowl centrifuges is a major challenge as the process and material behavior are complex and difficult to describe. A common approach to forecast the process behavior is to use analytical models and transfer the experience gained from the lab to the industrial scale. In this context, time-consuming and cost-intensive pilot scale experiments are necessary. This paper presents a methodology to improve the scale up process and make it more sustainable by using a numerical model that allows the real-time tracking of the process and a more reliable scale up process. For this approach, the material behavior is derived from laboratory experiments whereby the scalability is given. Here, the determination of material functions allows an accurate representation of the material behavior for solid bowl centrifuges of different scales. The focus of this paper is the detailed explanation of material related functions for the scale up of decanter centrifuges.     

Local solidosity of microcrystalline cellulose during dead-end filtration and sedimentation

Solid–liquid separation by filtration and sedimentation are important operations used in a wide range of industries. One important characteristic of both the filtration and sedimentation processes is the solidosity of the filter cake/sediment that is formed, affecting the efficiency and design of the separation. In this study local solidosity was investigated using a γ-attenuation method during both filtration and sedimentation experiments for microcrystalline cellulose, a highly crystalline cellulose with particles of about 2–80 μm in diameter. Constitutive relationships for the solidosity were investigated using both filtration (i.e. cake build-up and expression) and sedimentation data for experiments at different pH and suspension concentrations. The sedimentation behaviour under these different conditions was also investigated. It was found that a three parameter empirical model could be used to describe the constitutive relationship between local solidosity and local solid compressible pressure for the sediment formed and the filter cake after both cake build-up and expression. This correlation worked well for the material investigated even at low solid compressible pressures.     

Tailored surface roughnesses for enhanced deposition of fine liquid droplets from a flowing gas

Separating fine liquid droplets from a gas stream is an important operation in many industrial applications. In this paper, the effect of surface roughness on the deposition of droplets was investigated in a series of wind tunnel experiments. The roughness was modelled by 2-D rectangular ridges oriented at 45° to the flow direction. The rate of droplet deposition onto the surface was measured by a conductivity method. It was found that the deposition of droplets onto the roughened surface was enhanced by the roughness and the enhancement increased with ridge size-based Reynolds number. The maximum enhancement of droplet deposition on roughened surfaces over that of the smooth surfaces was observed to be around 150%. Data obtained for droplets with different sizes also indicated that the deposition rate of fine droplets was more dependent on the Reynolds than that of the large droplets. For relatively larger droplets, the enhancement of deposition is mainly caused by momentum-dominated impact. However, for fine droplets this is mainly due to the enhancement of local turbulence.     

Mechanism of Particle Separation in Small Hydrocyclone

The mechanism of particle separation in a small hydrocyclone is analyzed in this study. The separation efficiency of particles is affected by two major effects, the centrifugal and underflow effects. The fundamentals of these effects on the selectivity curve are derived from the theories of hydrodynamics. Three JIS particulate samples are separated in a 10-mm hydrocyclone. The proposed mechanism can be demonstrated by the available data. An increase in split ratio leads to an increase in the separation efficiency only for fine particles; consequently, a decrease in the separation sharpness results in a remarkable fishhook phenomenon. When the feed rate is increased by increasing the pressure drop through the hydrocyclone, the entire partial separation efficiency will be improved, but the separation sharpness and fishhook depth have no substantial varieties. The proposed mechanism can be used for explaining these phenomena, for the selection of optimum operating conditions, and for the hydrocyclone design.     

A TBP/BTBP-Based GANEX Separation Process – Part 3: Fission Product Handling

A Group ActiNide EXtraction (GANEX) separation system for transmutation has been developed, combining CyMe₄-BTBP with TBP and cyclohexanone. This new GANEX solvent has proven efficient in actinide extraction but also been found to extract some undesired fission products and corrosion products. Three major fission products were primarily selected for the study: Mo, Zr, and Pd. There are three main strategies for handling the extraction problem, all of which have been investigated and discussed; these are Pre-extraction, Suppression, and Scrubbing. The only strategy that was found to control the behavior of all three main fission products was suppression by the combination of two water-soluble complexing agents bimet and mannitol.     

Effect of Solvent Content on the Separation and the Energy Consumption of Extractive Distillation Columns

This article sets out to evaluate the effect of solvent content in the extractive section on the separation efficiency and energy consumption of extractive distillation columns. Contrary to the classical approach, the proposed approach enables a simultaneous evaluation of the effect of the major decision variables (reflux ratio, solvent flow rate, and the number of stages of the extractive section [NSE]). The procedure allows calculating the minimum solvent flow rate for the separation and the minimum specific energy consumption. The results show that the minimum specific energy consumption is obtained for the minimum reflux ratio and not for the minimum solvent flow rate. Moreover, the results show that it is not always the case that a larger NSE results in lower energy consumption. Due to its industrial importance, the dehydration of aqueous mixtures of ethanol using ethylene glycol as solvent has been chosen as a case study.