Efficiency Of Separation Process Research Articles

Совершенствование схемы и режима внутреннего водооборота пенной сепарации алмазосодержащих кимберлитов

The object of this study is the process of enrichment of diamond-containing kimberlites by foam separation. The subject of the research is the recycled water of the foam separation unit. The purpose of the study is to increase the foam separation process efficiency in the enrichment of diamond-containing kimberlites by improving the scheme and regime of internal water circulation. The objectives of the study are to study the effect of sludge on the surface condition and floatability of diamonds, to analyze the composition of sludge products and to establish the causes of the increase in the concentration of sludge in recycled water, to substantiate the approach to the choice of technologies and the development of schemes for desliming recycled waters of the foam separation cycle. To determine the degree of sludge influence on the surface composition and floatability of diamonds, the technique of electron probe X-ray spectral analysis has been used and experiments have been conducted on foam separation of a diamond-kimberlite mixture. Industrial tests of the modes and schemes of clarification of recycled water are carried out at the enrichment plant No. 3 of the Mirninsky Mining and Processing Plant (MPP). The results of X-ray electron spectroscopy show that there is a proportional dependence of the decrease in diamond floatability on the proportion of hydrophilic coatings on the diamond surface. For the destruction of organic-air-mineral aggregates, which are an essential source of sludge, it is proposed to use highly turbulent classification modes in a hydrocyclone, which allows separating grains of hydrophobic kimberlite minerals from drops of apolar collector. In the final stage of clarification of recycled water, it is proposed to use flotation classification technology in a three-product clarifier, which ensures the production of an aqueous phase purified from precipitating and surfacing fractions. The test results of the developed schemes and modes of recycled water desalination in the foam separation department of the processing plant No. 3 of Mirninsky MPP have showed a decrease in the concentration of sludge in recycled water by 2 times, a reduction in the consumption of flotation reagents by 7-10 % and an increase in diamond recovery by 1.2 %.

Integrated metal‐organic framework (MOF) and pressure/vacuum swing adsorption process design:MOFmatching

AbstractA two‐step integrated metal‐organic framework (MOF) and pressure/vacuum swing adsorption (P/VSA) process design has been recently established for gas separation. In the first step, selected MOF descriptors and process operating conditions are simultaneously optimized to maximize the process performance. Based on the obtained results, the second step (i.e., MOF matching) is addressed and exemplified by propene/propane separation in this work. Computational MOF synthesis and screening are explicitly carried out to find new advanced material candidates for enhancing the separation process efficiency. First, model‐based property‐performance relationships are developed for fast MOF screening. Then, MOF building blocks are extracted from 471 MOFs contained in the Computation‐Ready Experimental (CoRE) MOF database. With these building blocks, 45,472 hypothetical MOFs are created. After model‐based and molecular simulation‐based screening, six candidates are left and sent to P/VSA process optimization. Finally, three candidates are found to meet the predefined separation specifications and one candidate shows a better process performance than the best out of the 471 CoRE MOFs.

Current status in the copper ore processing (review)

The article provides the analysis of process flows used for sulfide and oxidized copper ore treatment, reagent schemes, process equipment, indicators of flotation concentration at a number of domestic and foreign concentrating mills and plants. Autogenous and semi-autogenous grinding mills are widely used at the ore preparatory processing at the first stage of grinding to eliminate medium and fine crushing stages. An alternative is the use of high pressure grinding rolls that can reduce electricity consumption as compared to autogenous and semi-autogenous grinding. There is an increase in the use of large-volume and high-performance ore-preparation and flotation equipment for maintaining the quality and quantity of the product. In addition to ball mills, fine and ultrafine regrinding mills of various configurations are widely used at the stage of rougher flotation concentrate regrinding. The analysis of flotation reagents used to improve separation process efficiency was conducted with domestic and foreign approaches to flotation reagent selection shown. It is noted that foreign concentrating mills often use a combination of main and additional collectors. The paper provides the data on flotation reagents used in the copper sulfide and oxidized ore concentration, and their consumption. A combined diagram of flotation-hydrometallurgical processing of mixed copper ore from the Udokan deposit is considered. Conclusions are drawn about current trends in the processing of copper ores including the choice of equipment.

Determination of the air separator circulation path parameters

The article discusses the separation process efficiency issue of the fine powders in an air separator. The aerodynamic scheme of the air separator is proposed and the schemes of the gas-material flow through the elements of the separator gas-material path are considered. The equations of the gas-material flow motion through the separator gas-material path elements are proposed. The calculation of the air separator various operating modes is proposed. The results of an approximate graphical-analytical calculation of the gas-material path of the proposed aerodynamic scheme for the air separator are presented. A high convergence of theoretical positions with the performed experiments is shown.

Dynamic Modeling Using Artificial Neural Network of Bacillus Velezensis Broth Cross-Flow Microfiltration Enhanced by Air-Sparging and Turbulence Promoter.

Cross-flow microfiltration is a broadly accepted technique for separation of microbial biomass after the cultivation process. However, membrane fouling emerges as the main problem affecting permeate flux decline and separation process efficiency. Hydrodynamic methods, such as turbulence promoters and air sparging, were tested to improve permeate flux during microfiltration. In this study, a non-recurrent feed-forward artificial neural network (ANN) with one hidden layer was examined as a tool for microfiltration modeling using Bacillus velezensis cultivation broth as the feed mixture, while the Kenics static mixer and two-phase flow, as well as their combination, were used to improve permeate flux in microfiltration experiments. The results of this study have confirmed successful application of the ANN model for prediction of permeate flux during microfiltration of Bacillus velezensis cultivation broth with a coefficient of determination of 99.23% and absolute relative error less than 20% for over 95% of the predicted data. The optimal ANN topology was 5-13-1, trained by the Levenberg–Marquardt training algorithm and with hyperbolic sigmoid transfer function between the input and the hidden layer.

A novel collector with wide pH adaptability and high selectivity towards flotation separation of scheelite from calcite

In this work, we synthesize a new type of Gemini surfactant (hexane-1,6-didodecyldimethylammonium bromide, HDDA) to be used for the first time as a collector for the froth flotation separation of scheelite from calcite. Micro-flotation experiments with HDDA show the recovery efficiency of scheelite greater than 91% (maximum value of 95%), while recovery efficiency of calcite observes at smaller than 40% (minimum value of 14%) over a wide range of pH (6–11). The best separation pH is found as 7. Moreover, the separation process efficiency in presence of HDDA is greater than that of conventional sodium oleate in the flotation of binary minerals. The tungsten trioxide (WO3) grade of concentrate based on HDDA can reach to 65% at pH 7, which is obviously larger than that when sodium oleate is used (40%), which is in accordance with the single mineral flotation results. The results indicate the superior selectivity, outstanding collecting capacity and excellent pH adaptability of HDDA in the flotation separation process.

Cefalexin crystallization residual liquor separation via nanofiltration based multistage process

Pharmaceuticals manufacture is of importance to human life and health. Great amount of pharmaceuticals crystallization residual liquor was produced in the pharmaceuticals manufacture, which lead to adverse influence on the green chemical engineering and environment. Herein, we proposed a multistage separation process based on nanofiltration technology to recover cefalexin crystallization residual liquor separation. The influence of membranes, pH value, concentration as well as separation stages on the separation performance was explored. The nanofiltration membrane (NF-200D) with strong electronegative charge showed a high rejection of 74.00% for 7-amino-3-desacetoxycephalosporanic acid (7-ADCA) and low rejection of 7.06% for D-phenylglycine in mixed solution. The increase in the electronegative charge of NF membranes could enhance the repulsion between membrane and solute molecules. The separation factor of nanofiltration membrane for 7-ADCA and D-phenylglycine reached a peak value of 3.06 at pH 8.0 and concentration of 10 mmol L−1. Using three stage separation, the concentrated 7-ADCA (C7-ADCA = 23.12 g L−1) and the permeate D-phenylglycine (CD-phenylglycine = 0.19 g L−1) were obtained. Further improved separation sequence should focus on the preparation of nanofiltration membranes with strong electronegative charge and acid-base tolerance, and the nanofiltration process design with enhanced efficiency of separation process.

Synthesis and Characterization of Cellulose Acetate Membranes with Self-Indicating Properties by Changing the Membrane Surface Color for Separation of Gd(III)

This study presents a new, revolutionary, and easy method for evaluating the separation process through a membrane that is based on changing the color of the membrane surface during the separation process. For this purpose, a cellulose acetate membrane surface was modified in several steps: initially with amino propyl triethoxysilane, followed by glutaraldehyde reaction and calmagite immobilization. Calmagite was chosen for its dual role as a molecule that will complex and retain Gd(III) and also as an indicator for Gd(III). At the contact with the membrane surface, calmagite will actively complex and retain Gd(III), and it will change the color of the membrane surface during the complexation process, showing that the separation occurred. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA-DTA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, demonstrating the synthesis of membrane material with self-indicating properties. In addition, in the separation of the Gd(III) process, in which a solution of gadolinium nitrate was used as a source and as a moderator in nuclear reactors, the membrane changed its color from blue to pink. The membrane performances were tested by Induced Coupled Plasma–Mass Spectrometry (ICP-MS) analyses showing a separation process efficiency of 86% relative to the initial feed solution.

Sorption of carbendazim and linuron from aqueous solutions with activated carbon produced from spent coffee grounds: Equilibrium, kinetic and thermodynamic approach

Spent coffee grounds (SCG) have been used for the production of activated carbon (AC) by impregnation with different ratios of phosphoric acid at 600 °C, Xp (H3PO4/coffee): 3:130%, 4:130%, 3:150% and 4:150%. The obtained AC was characterized by BET, FTIR and SEM. BET surface area corresponds to 803.422 m2 g−1. The influences of the main parameters such as contact time, the pesticides initial concentration, adsorbent dose, pH and temperature on the efficiency of separation process were investigated during the batch operational mode. Results were modeled by adsorption isotherms: Langmuir, Freundlich and Temkin isotherms, which gave satisfactory correlation coefficients. The maximum adsorption capacities calculated from the Langmuir isotherms were 11.918 mg g−1 for carbendazim and 5.834 mg g−1 for linuron at room temperature. Adsorption kinetics of carbendazim and linuron have been studied by the pseudo-first-order, the pseudo-second-order and the intraparticle diffusion model. The results of adsorption kinetics have been fitted the best by pseudo-second-order model. The resulted data from FTIR characterization pointed to the presence of many functional groups on the AC surface. SCG adsorbent, as an eco-friendly and low-cost material, showed high potential for the removal of carbendazim and linuron from aqueous solutions.

Improvement of the sunflower seed separation process efficiency on the vibrating surface

The study of the sunflower seed separation process during its movement on the vibrating surface has been carried out in two stages. The first (theoretical) stage has been implemented in the software package STAR-CCM + using the corresponding physical models. The second stage is the conduct of experimental research on a pilot sample with a base of vibrating pneumatic PVS table. As a result of numerical simulation and experimental studies of the sunflower seed separation process during its movement on the vibrating surface, we have determined the dependences of the change in the distribution coefficient, productivity and power consumed by the vibrating pneumatic separator from the seed supply, the inclination angles of the vibrating surface, the frequency and amplitude of its oscillation and the velocity of the airflow V. The statistical analysis has shown that the correlation coefficient between the theoretical and experimental dependencies in the variation of the values of the factors in the given range is 0.88-0.92. The technological and constructive scheme of the adaptive vibrating pneumatic separator with rationally defined regime parameters (seed supply, airflow velocity, deck oscillation frequency, deck inclination angle) has been developed basing of the obtained theoretical and experimental dependencies, using the software which is based on the created algorithm, allowing to perform the technological process of sunflower seed mixtures separating by volume density with higher productivity and quality.

H2S and CO2 capture from gaseous fuels using nanoparticle membrane

This work investigates the simultaneous removal of CO2 and H2S from natural gas by a novel PVDF membrane structure using CaCO3 nanoparticles aiming at increasing the efficiency of separation process. This work presents to what extent the CaCO3 nanoparticles improve the separation efficiency; proposes the optimum range of nanoparticle share in the membrane for achieving maximum separation in increased flow rates; and finally evaluating the effects of operational conditions such as temperature, flow velocity and species concentration on the system performance.A mathematical finite element model is developed to simulate the gas removal using a membrane module including both mass transfer equations and chemical reaction mechanism. A good agreement has been achieved between the modeling results and the measured data. It is found that 20% CaCO3 nanoparticle share in membrane gives the highest separation efficiency and any higher or lower nanoparticle concentration reduces the gas separation efficiency. Gas and fluid velocities have a high impact on separation efficiency. For example, increase in gas velocity from 5 m/s to 20 m/s leads to reduction in CO2 removal efficiency from 82% to 42% and H2S efficiency from 100% to 60%.

Modern sulfocationites for separation of lanthanides and transplutonium elements partitioning via displacement complexing chromatography

Separation of rare earth elements (REE) as a model system for transplutonium elements (TPE) partitioning via displacement complexing chromatography technique was investigated using sulfocationites commercially available from Purolite (UK), Dow Chemical (USA), Rohm and Haas (USA), and LLC SPA ‘Tokem’ (Russia). The specific volume, total mass and volume capacity of the sorbents were determined. Effects of the dispersity (monodispersed and polydispersed), grain size and cross-linking degree on the REE and TPE separation performance were discussed. Materials and conditions for the highest REE and TPE separation process efficiency were selected.

Influence of elements thickness of separation devices on the finely dispersed particles collection efficiency

This article presents a rectangular separator, developed by the authors, for purification of a multiphase gas flow from the finely dispersed particles with a diameter of up to 10 µm. In order to increase the separation process efficiency, a research was conducted to determine the optimum thickness of I-beam elements within the separator at different values of the flow inlet rate and length of I-beam elements. It was found that change in the wall thickness of elements leads to a change in the flow structure, which causes a decrease in the dust particles collection efficiency.

Applying CFD in the Analysis of Heavy Oil/Water Separation Process via Hydrocyclone

In recent years most of the oil reserves discovered has been related to heavy oil reservoirs whose reserves are abundant but still show operational difficulties. This fact provoked great interest of the petroleum companies in developing new technologies for increasing the heavy oil production. Produced water generation, effluent recovered from the production wells together with oil and natural gas, is among the greatest potential factors for environmental degradation. Thus, a new scenario of the oil industry appears requiring improvement in treatment units for produced water. Among the technological improvements in the facilities, the use of hydrocyclones has been applied in the treatment of the oily water. In this sense, this study aims to investigate numerically the separation process of heavy oil from a water stream via hydrocyclone, using the computational fluid dynamics technique. In the mathematical modeling was considered a two-phase, three-dimensional, stationary, isothermal and turbulent flow. Results of streamlines, pressure and volume fraction fields of the involved phases (oil and water) into the hydrocyclone, and mechanical efficiency and pumping power of the fluids are shown and analyzed. In conclusion, it seems that with increasing fluid input velocity in the device there is an increase in pressure drop, indicating a greater pumping energy consumption of the mixture, and greatly influences the separation process efficiency.

Experimental study of the application of rotating fluidized beds to particle separation

Rotating fluidized beds provide a unique opportunity to exploit fluidization under higher particle forces. The centripetal force in a rotating fluid bed is typically on the order of 10 times the force of gravity. Since the force keeping the particles in the unit is larger, the drag force can also be larger, allowing for higher gas and slip velocities. This operating regime provides intensified gas-solids contact through higher mass transfer, heat transfer, gas throughput, and bubble suppression.One application for using a rotating fluidized bed is in Chemical Looping Combustion (CLC). When solid fuels are used, oxygen carrier and ash are mixed in the process. In order to maintain high carbon capture efficiencies and recyclability of the oxygen carrier, the ash needs to be separated from the oxygen carrier. This separation can be done aerodynamically since the oxygen carrier is larger and heavier than the ash. It is theorized that rotating fluidized beds could improve both the gas-solid and solid-solid separation process efficiency and throughput as compared to conventional fluidized beds.A 43cm diameter, 2.5cm long vortex chamber has been designed and constructed to investigate the application to particle separation. A series of experiments have been performed to investigate the separation of different binary mixtures of solids. These experiments demonstrate the use of a rotating fluidized bed for high-G intensified particle separation that can be combined with high-G intensified gas-solids contact and gas-solids separation.

Radiation Influencing of the Extraction Properties of the CyMe4-BTBP and CyMe4-BTPhen Solvents with FS-13

The radiolytic stability of two ligands, CyMe4-BTBP and CyMe4-BTPhen in system with the FS-13 (phenyl trifluoromethyl sulfone) diluent was investigated under irradiation by accelerated electrons to study impact of the degradation products on the separation process efficiency and safety. Irradiation experiments were carried out up to the absorbed dose of 200 kGy. The irradiated samples were analysed by HPLC for the degree of extractant degradation. In addition, the effect of the presence of HNO3 during the irradiation was studied. Extraction properties of the irradiated solvents were evaluated and compared with the extraction properties of non-irradiated solvents to assess the impact of the degradation products on extractions properties.The results obtained show that the stabilities of these ligands are higher in FS-13 than in the cyclohexanone-type solvents. The extraction properties are significantly influenced by degradation products contained in these systems. Surprisingly, both the distribution ratios for americium and europium, and the Am/Eu separation factor increase with the absorbed dose for the system withCyMe4-BTPhen in FS-13. Obviously, the degradation products of this ligand are efficient extractants too. In the next phase, an attempt will be done to identify the main degradation products, synthesise them and study their extraction properties.

Flocculation and Separation of Oil Droplets in Ultrasonic Standing Wave Field

A new method for breaking oil in water emulsion based on flocculation of droplets in high intensity ultrasonic standing wave field was developed in this study and the effect of initial droplets size, type of disperse phase as well as the time of sonication and the height of emulsion in the chamber on the extent of interdroplet interactions were investigated. The results showed that type of disperse phase affects the efficiency of separation process through controlling the initial size of droplets. For the two types of disperse phase in question the efficiency of separation was calculated to be 42.7% for canola oil/water emulsion and 37% for sunflower oil/water emulsion. The time of sonication was found to have a positive contribution to the percent of flocculation and coalescence, so that the largest aggregates were formed after 30 minutes treatment. Also, the optimum height of emulsion in the treatment chamber was determined to be λ/4 at which the strongest flocculation and highest percent of coalescence took place. Increasing the height of emulsion did not significantly influence the course of aggregation and separation.

Velocity measurement in the hydrocyclone by oil droplet, doppler ultrasound velocimetry, and CFD modelling

AbstractTo develop the water treatment process, the hydrocyclone is now used as a unit to operate. Understanding hydrodynamics is a key step to improve the separation process efficiency. Recently, a new simple method called the oil droplet method was proposed by Bamrungsri et al. [Chem. Eng. Res. Design 86, 1263‐1270 (2008)] and applied to velocity measurements in a hydrocyclone.The Doppler Velocimetry measurements and computational fluid dynamics (CFD) have been proposed by many researchers as effective for studying the flow field of a hydrocyclone. This work presents a comparison of the experimental results from these two methods along with those obtained from numerical simulations. The numerical calculations of the 3D flow field were performed with FLUENT using the k‐ε model and the Reynolds stress model (RSM). Measurements and CFD simulations were performed for two hydrocyclone configurations (5 and 10 cm diameter).Doppler ultrasound velocimetry data and CFD–RSM results are in close agreement. The oil droplet method is less accurate for the continuous phase velocity profiles but is promising for the validation of Lagrangian tracking simulations.

Studies on Transport of Vanadium (V) and Nickel (II) from Wastewater Using Activated Composite Membranes

Third International Conference on Engineering for Waste and Biomass Valorization, May 2010, Beijing, China. The metals such as vanadium, nickel and iron are identified in the typical crude oils extracted from oil bearing rocks. The produced water contains salts, heavy metals, emulsified oil and other organics after the hot water extraction process (HWEP) of bitumen from oil sands. This is a serious environmental problem waiting for technically and economically feasible solutions. Membrane technologies such as ultra filtration, nanofiltration, and reverse osmosis are widely used in water purification and they are also applied for produced-water (wastewater stream in oil and gas production) purification. This study focuses on the transport of Vanadium (V) and Nickel (II) through activated composite membranes (ACMs) based on carrier Aliquat 336, in cyclohexane and dodecane. Reagents and materials, without further purification, and double distilled water were used. The UV-visible spectrophotometer and Atomic Absorption Spectrometer (FAAS) were utilised for measuring the concentrations of metal ions from aqueous solutions. Optimum conditions for both feed (pH 8) solutions, the influence of hydrodynamic conditions, the concentration of carrier on membrane (0.2, 0.5 and 0.7 M), the influence of aqueous feed acidity (4 < pH < 7), the influence of permeate reagents (NH3, HNO3, and Na2CO3) and the efficiency of separation process were established. The experiments were carried out at 20°C and low concentrations of V (V) and Ni (II), between 5 and 25 ppm, for modelling, as good as possible, one matrix of industrial wastewaters which contain V (V) and Ni (II) after HWEP. The coupled transport of vanadium from aqueous solutions following the reactions: $$ \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{Cl}}^{ - } } \right) \, _{\text{org}} \, + {\text{ VO}}_{ 2} \left( {\text{OH}} \right)_{ 2}^{ - } \rightleftarrows \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{VO}}_{ 2} \left( {\text{OH}} \right)_{ 2}^{ - } } \right)_{\text{org}} + {\text{ Cl}}^{ - } $$ $$ \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{VO}}_{ 2} \left( {\text{OH}} \right)^{ - }_{ 2} } \right)_{\text{org}} + {\text{ 2 OH}}^{ - } \rightleftarrows \left( {{\text{R}}_{ 4} {\text{N}}^{ + } {\text{OH}}^{ - } } \right)_{\text{org}} \, + {\text{VO}}_{ 3} {\text{OH}}^{ 2- } \, + {\text{ H}}_{ 2} {\text{O}} $$ The removal of V (V) and Ni (II) from wastewater samples was found to be governed by the carrier concentration used as well as the conditions of the aqueous feed and permeate solutions. The good efficiency of activated composite membranes separation was observed in case of V (V). The selectivity of Aliquat 336 based ACM toward V (V) and Ni (II) is presented and discussed. Selectivity demonstrated that vanadium ions were removable from mixtures due to the different extraction strength of Aliquat 336. Such selectivity is based on the difference of the dynamic behaviour of the metal ions transport.

Design of Optimal Process Flowsheet for Fractional Crystallization Separation Process

A procedure is presented that synthesizes fractional crystallization separation processes to obtain pure solids from multi-component solutions. The method includes a procedure to generate a network flow model to identify alternative process designs for fractional crystallization. The main advantage of this systematic procedure with respect to other reported procedures is using non-equilibrium solubility values for crystallizers and mixing tanks as process points. By employing an approach factor to show the distance from equilibrium, a non-linear programming model is obtained. Solving the non-linear programming model, optimal process flowsheet and the corresponding non-equilibrium solubility values for process points are presented. The proposed procedure is used to design an optimal flowsheet for production of sodium carbonate and sodium sulfate from Burkeite. The results show that when the approach factor goes to unity, the maximum efficiency of separation process is attained which corresponds to the minimum total flow rates and total cost of the process.