• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.137-144
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• 2015

The present paper deals with the extractive separation and selective recovery of nickel and lithium from the sulfate leachate of cathode scrap generated during the manufacture of LIBs. The conditions for extraction, scrubbing and stripping of nickel from lithium were optimized with an aqueous feed containing $2.54kg{\cdot}m^{-3}$ Ni and $4.82kg{\cdot}m^{-3}$ Li using PC-88A. Over 99.6% nickel was extracted with $0.15kmol{\cdot}m^{-3}$ PC-88A in two counter-current stages at O/A=1 and pH=6.5. Effective scrubbing Li from loaded organic was systematically studied with a dilute $Na_2CO_3$ solution ($0.10kmol{\cdot}m^{-3}$). The McCabe-Thiele diagram suggests two counter-current scrubbing stages are required at O/A=2/3 to yield lithium-scrubbing efficiency of 99.6%. The proposed process showed advantages of simplicity, and high purity (99.9%) nickel sulfate recovery along with lithium to ensure the complete recycling of the waste from LIBs manufacturing process.

• Korean Journal of Materials Research
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• v.19 no.12
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• pp.661-666
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• 2009

Froth flotation has been carried out in order to produce roasting-molybdenite concentrate from molybdenite ore in the Shin-yeomi mine. In our study, roasting-molybdenite (Mo 0.43%) from Shin-yeomi mine was recovered by varying the conditions of regrinding time, dosage of collector and alkalinity. Liberation and flotation efficiency more were effective at regrinding time of six minutes than at single grinding. Mo recovery curves increased considerably as dosage of kerosene increased, whereas Mo grade curves decreased gradually. The separation efficiency of molybdenite was effective when the dosage of collector (kerosene) was adjusted to 300 g/t. The molybdenite concentrate was agglomerated in the range of pH 5-7 and its separation efficiency increased to pH 9-10. The concentrate of 49.5% Mo grade ($MoS_2$, 82.6%) with 81.5% recovery from Shin-yeomi molybdenite ores was obtained under conditions of 20% pulp concentration, 300 g/t kerosene 325 g/t frother (AF65), 2.5 kg/t depressant ($Na_2SiO_3$), pH 9-10 and four cleaning times. In the future, a trial run that can separate up to 50% Mo grade from Shin-yeomi molybdenite ores will be performed.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.590-597
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• 2003

Processing and smelting of copper containing sulphide concentrates result in the accumulation of impurities into various process streams. All primary copper smelters and refineries around the world produce significant amounts of slag, dust, sludge, residues and others, which contain copper and precious metals. The recovery of these valuable metals is essential to the overall economics of the smelting process. Physical, chemical and mineralogical characterization of particular slag and Cottrell dusts from primary smelters and $Dor\'{e}$ furnace (TBRC) slag and Pressure Leached Anode slimes from a copper refinery have been carried out to understand the basic behind the recovery processes. Various process options have been evaluated and adapted for the treatment of slag from different smelting furnaces and Cottrell dusts as well as the intermediate products from copper refineries. Besides the hydro- or pyro-metallurgical treatments, the above mentioned physical separation options such as magnetic, gravity separation, flotation and precipitation flotation processes have been successfully identified and adapted as the possible process options to produce a Cu-rich or precious metal-rich concentrates for in-house recycling and other valued by-product for further treatment. The results of laboratory, pilot plant and production operations are presented, and incorporation of several alternative flowsheet is discussed in this paper.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2003.10a
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• pp.22-34
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• 2003

Processing and smelting of copper containing sulphide concentrates result in the accumulation of impurities into various process streams. All primary copper smelters and refineries around the world produce significant amounts of slag, dust, sludge, residues and others, which contain copper and precious metals. The recovery of these valuable metals is essential to the overall economics of the smelting process. Physical, chemical and mineralogical characterization of particular slag and Cottrell dusts from primary smelters and Dore furnace (TBRC) slag and Pressure Leached Anode slimes from a copper refinery have been carried out to understand the basic behind the recovery processes. Various process options have been evaluated and adapted for the treatment of slag from different smelting furnaces and Cottrell dusts as well as the intermediate products from copper refineries. Besides the hydro- or pyre-metallurgical treatments, the above mentioned physical separation options such as magnetic, gravity separation, flotation and precipitation flotation processes have been successfully identified and adapted as the possible process options to produce a Cu-rich or precious metal-rich concentrates for in-house recycling and other valued by-product for further treatment. The results of laboratory, pilot plant and production operations are presented, and incorporation of several alternative flowsheet is discussed in this paper.

• Resources Recycling
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• v.29 no.6
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• pp.15-26
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• 2020

In recent years, there is an increasing interest in environmental friendly treatment of waste-plastics in terms of the generation of microplastics. Accordingly, the recycling of waste-plastics is very important because it provides advantages of volume reduction, mitigation of carbon dioxide emission, and reproduction of value-added products. In particular, in order to recycle the eco-friendly waste-plastics, it is necessary to use a physical separation methods, and among them, flotation separation, which can separate material (i.e., polymer component) in waste-plastics is well known as a very effective separation method in terms of material recycle. Therefore, in this review, the research trend of flotation separation for effective separation of mixture waste-plastics was investigated. In addition, through the reported research results, approaches to use as new functional materials from polymers, which are raw materials for waste-plastics, are summarized.

• Membrane Journal
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• v.33 no.4
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• pp.222-232
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• 2023

In this study, a hollow fiber support membrane was prepared by a non-solvent induced phase separation (NIPS) method using a polysulfone (PSf). The prepared hollow fiber support membrane was coated with PDMS and Pebax to prepare a hollow fiber composite membrane. The prepared composite membrane was measured for permeance and selectivity for pure CO₂, H₂, O₂ and N₂. Gas separation performance of the module having the highest selectivity (CO₂/H₂) among the prepared composite membrane modules was measured according to the change in stage cut using simulated gas. The composition of the simulated gas used at this time was 70% CO₂ and 30% H₂. In the 1 stage experiment, it was possible to obtain values of about 60% of H₂ concentration and 12% of H₂ recovery. In order to overcome the low H₂ concentration and recovery, 2 stage serial test was performed, and through this, it was possible to achieve 70% H₂ concentration and 70% recovery. Through this, it was possible to derive a separation process configuration for CO₂/H₂ separation.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.33-39
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• 1989

Pure separation of various leukocytes is required for the assessment of their roles in immunological and phisiological function. In this study, pure separation of monocytes from canine peripheral blood was attempted. At first, mononuclear cells (PBMC) were separated by ficoll-hypaque gradient method and then monocytes were recovered from PBMC suspensions in sucrose gradient Sol. (PBMC-Sucrose), autologous plasma (PBMC-Plasma) and autologous serum (PBMC-Serum) incubated at $37^{\circ}C$ for 2 hours. 1. In the separation of PBMC by ficoll-hypaque gradient method in canine blood, higher relative centrifugal force (RCF) was required, as high as more than 1,300xg RCF for 40 minutes, for clear formation of PBMC layer than that in human blood as usually used 400xg RCF for 40 minutes. 2. In monocytes-separation from three PBMC suspensions following PBMC separation, recovery-, purity- and viability-rate of monocytes showed better results in PBMC-Plasma and PBMC-Serum than in PBMC-Sucrose suspension, particulary showing better results from PBMC suspensions performed by centrifugation at 1,500xg RCF for 40 minutes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.1
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• pp.69-75
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• 2009

This paper studies the aerodynamic performance that the vent mixer-new conceptual supersonic mixer-showed with its geometric characteristics. The hole is 2 mm with 2 mm's distance from the wall in case 1 and with no distance in case 2. In case 3 die hole is 1 mm. Case 1 and case 2 showed the same total pressure recovery ratio, of which the case 3 was lower than that. While cases 1-3 had the same reattachment length, the shear layer was thicker in cases 1 and 2 than in case 3. Within the recirculation zone, cases 1 and 2 had lower pressure loss and higher velocity gradient difference than case 3-they enhance mixing between air and fuel. Separation bubble which is developed by the inflow into the recirculation zone has a significant effect on the total pressure recovery ratio in the combustor. Also separation bubble influences pressure distributions and recirculation flows in the recirculation zone. Therefore, inflow rate of air into the recirculation zone mainly affects the performance of vent mixer.

• Membrane Journal
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• v.23 no.2
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• pp.176-184
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• 2013

To investigate the performance of VOC separation, composite hollow fiber membrane was prepared which composed of poly (ether imide) support prepared by phase separation method and poly (dimethylsiloxane) coating active layer. The performances of the membranes for the application of recovery process in terms of their morphology, gas permeance test for $N_2$ and $O_2$ gases. Durability against benzene, toluene and xylene was also investigated. And permeation test for multi-component VOCS through the membrane with different feed concentration and stage-cut were investigated. Permeance of PEI supported membrane and the membranes coated with PDMS decreased from 45,000 GPU to 63 GPU and 49,450 to 30 GPU for $N_2$ and $O_2$, respectively. Recovery efficiency and concentration of VOCs in permeate increased with decreasing stage-cut. VOCs concentration in permeate proportionally increased with increasing feed concentration but concentration ratio and recovery efficiency showed any noticeable changes with feed concentration change.

• Membrane Journal
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• v.22 no.1
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• pp.54-61
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• 2012

To separate and recover of VOCs, supporting membranes using PEI were prepared by phase separation method and it was coated with PDMS to prepare PEI-PDMS hollow composite membrane. To investigate characteristic of prepared membrane, pure gas permeability was measured using oxygen and nitrogen, the stage cut and permeance property with feed concentration were evaluated using xylene, ethyl benzene, toluene and cyclohexane. Also, to check solvent resistance on VOCs, stress-strain property of membrane with immersion time in solvent were measured by DMA. The permeance value of $O_2$ and $N_2$ showed 63 GPU and 30 GPU respectively. Permeated VOCs concentration was decreased with increasing stage cut. But, conversely, recovery efficiency that was increased with increasing stage cut. As a result of DMA test, the stress and strain were 11.93 MPa and 13.52%, respectively.