• Journal of Environmental Science International
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• v.24 no.1
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• pp.9-15
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• 2015

Sustainable and eco-friendly polymers, natural polymers, bio-based polymers, and degradable polyesters, are of growing interest because of environmental concerns associated with waste plastics and emissions of carbon dioxide from preparation of petroleum-based polymers. Degradable polymers, poly(butylene adipate-co-terephthalate) (PBAT), poly(propylene carbonate) (PPC), and poly(L-lactic acid) (PLLA), are related to reduction of carbon dioxide in processing. To improve a weak mechanical property of a degradable polymer, a blending method is widely used. This study was forced on the component separation of degradable polymer blends for effective recycling. The melt-mixed blend films in a specific solvent were separated by two layers. Each layer was analysed by FT-IR, DSC, and contact angle measurements. The results showed that each component in the PPC/PLLA and PPC/PBAT blends was successfully separated by a solvent.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.719-724
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• 2001

The objective of this investigation was to separate silicon and silica for recycling by the liquid-liquid separation technique. In the preparation of silicon (Si) single crystal, a small amount of silicon is fixed on the surface of silica (quartz, $SiO_2$) crucible. The used crucible is crushed for recycling both silicon and silica in a high purity from the mixed powder. Zeta-potential of silicon and silica are almost the same at pH higher than 3. Their separation by simple flotation is ruled out. However, their hydrophobic characteristics are different in several different organic solvent from the measurement of contact angle. Therefore, the liquid-liquid extraction is employed to separate silicon and silica. The result indicates that the organic solvent mixed with dodecyl ammonium acetate could extracted the silicon powder at high purity (97-100%) with high recovery from the silica powder in the water phase.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.548-552
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• 2001

This study was designed to find optimum conditions of four different factors (ratio of solvent to cholesterol-$\beta$-cyclodextrin complex, mixing speed, mixing temperature, and mixing time) for cholesterol dissociation in cream. Using the ratio of 6 to 1 (solvent to the complex) showed the highest cholesterol dissociation rate (82.50%) when mixed at 100 rpm at $50^{\circ}C$ for 1 h. Mixing speed did not significantly affect the cholesterol dissociation. Also, mixing time appeared to be insignificant. The optimum mixing temperature was $50^{\circ}C$ and mixing at $40^{\circ}C$ resulted in a significantly lower rate, compared with that at $50^{\circ}C$. In a subsequent experiment, using recycled $\beta$-cyclodextrin only showed 75.07% of cholesterol removal in cream, while the mixture of recycled to unused $\beta$-CD with the ratio of 6 to 4 increased cholesterol removal to 95.59%, which is highly close to that of 100% unused $\beta$-CD.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.218-226
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• 2004

Solvent extraction and stripping experiments were conducted to separate iron from a spent $FeCl_3$ etching solution containing nickel. In the extraction, PC88A, MIBK and Alamine336 were tested as an extractant in various diluents. Alamine336 salt in toluene led to the highest extraction percentage of iron. Stripping percentage of iron from the loaded organic by Alamine336 increased with decreasing HCl conentration of stripping solution and with increasing volume ratio of aqueous to organic. In the operation of bench scale mixer-settler, 7 extraction stage with 1.0M Alamine336 salt in toluene and 10 stripping stage with 0.01M HCl solution resulted in a stripped solution with 133g/L of iron and in a raffinate with most of nickel together with a small amount of iron when the flow rate ratio of organic to aqueous was 7.

• Resources Recycling
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• v.7 no.2
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• pp.9-15
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• 1998

Recovery af molybdenum in spent desulfuriring catalyst of petrochemical industries was studied from MfGnatc solulion which is a resultant of firstly remvercd vanadium by wet processes. In order to separate and recover molybdenum from upper mentioned rafinatz solution containing several mctal ions, such as molybdenum (1,100 ppm), vanadium (150 ppm), aluminium (19 ppm), and nickel (33 ppm), either adsorption technique by chelate resin or solvent extr~ction by tertiary amine as extractant was applied. In case of adsorption method, palyamine type chelate resin showed the highest selectivily far molybdenum ion up lo 60 ddm' of ancentration aftcr eluting with 3.0 rnolld~n' of NH,OH. On the othcr hand. molybdenum ion wa cffectlvely cxtractcd in Ule whole ranges of equilibrilrm pR by solvent extraction method with 10 ~01%-alamine 336 which was pretreated with 2N-HCI

• Resources Recycling
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• v.14 no.5 s.67
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• pp.40-44
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• 2005

The purified phosphoric acid was recovered from crude phosphoric acid with high contents of aluminium and molybdenum ions to reuse the acid as an etchant. In this work, solvent extraction was applied to recover the phosphoric acid from crude phosphoric acid. Phosphate was used as an extractant. Further cleaning and removing processes on the recovered phosphoric acid were conducted to eliminate the metallic ion impurities in the acid. The process parameters were successfully optimized, so that the finally purified acid contained less than 1 ppm of aluminium and molybdenum ion.

• Resources Recycling
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• v.6 no.3
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• pp.9-14
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• 1997

A study has been made of the rccovery of copper (11) by solvent extraction with Alamine336 (Tri-n-oclylamine) as a extractant from hydrochloric etching solutions. The effect of extractant concentrations, hydrochloric acid, chloride Ion concentrations and phase ratio (organiclaqueaus) on copper extraction were studied. Experimental results showed that the concenl~atiano f extractant and the phase ratio strongly influenced the copper extraction, and the extraction percent of capper Increased at higher hydrochloric acid and chloride ion mncmhation. We proposed that the optimum extrachon stages of copper for continuous extraction process by analysidng thc McCabe-Thielc diagram. Stripping of copper from the loaded organic phases wn be accomplished by pure water (H, O) as a dripping reagent effectively. As the tcmpcrature is increased, thc stripping of copper is enhanced.

• Resources Recycling
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• v.20 no.2
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• pp.60-66
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• 2011

Solvent extraction experiments were carried out to recover and separate Ru(III) from aqueous hydrochloric acid media using TBP and Cyanex923. The efficiency of the extraction was studied under various experimental conditions, such as concentration of HCl and NaCl, concentration of extractant in the organic phase and temperature. The extraction behavior of metal impurities, such as Pt, Bi, Sn, Fe, Pb and Cu in mixed solutions was examined. From the experimental studies, it was found that the Cyanex923 resulted in higher extraction percentage of Ru than TBP. However TBP was more effective for the separation of Ru and Pt, Bi, Sn in mixed solutions than Cyanex923.

• Resources Recycling
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• v.30 no.5
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• pp.32-37
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• 2021

Thorium extraction and possible separation from monazite leaching solution was studied. Primary amine Primene JM-T was select ed for t horium ext ract ion processing. Various experiment s were t est ed and est ablished for t he t horium liquid -liquid extraction process. The screening of extractant, lower pH conditions, extractant variation and extraction isotherms construction, and finally, stripping studies were established.

• Resources Recycling
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• v.29 no.6
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• pp.79-87
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• 2020

The extraction and stripping of HCl from aqueous solutions by commercial extractants like LIX 63 and its mixture with TEHA/ Cyanex 923/ Aliquat 336 and ionic liquids like ALi-SCN, ALi-PC in kerosene was investigated. Among these extractants, ALi-PC showed the best extraction effectivity (above 80%), but it was difficult to strip HCl from the loaded phase. Although the extraction percentage of HCl by LIX 63 was not high, the stripping performance was above 81%. The addition of octanol to the organic phase led to negative effect on the extraction performance of HCl. The addition of C2H5OH into aqueous solutions significantly increased the extraction and stripping percentage of HCl by LIX 63, ALi-PC and ALi-SCN.