• Resources Recycling
• /
• v.22 no.5
• /
• pp.35-42
• /
• 2013

Solvent extraction experiments have been performed to investigate an optimum condition to separate Nd and Pr from chloride solutions using PC88A and D2EHPA. In our experimental ranges, the distribution coefficients of Nd were higher than those of Pr. In both of PC88A and D2EHPA extractant system, our results indicated that the increase in concentration ratio of extractant to metal had a great effect on the extraction and separation of the two metals. In extraction with saponified D2EHPA, the initial pH of the aqueous solution and saponification degree had some effect on the extraction of the two metals but little effect on the separation factor.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.48 no.3
• /
• pp.255-264
• /
• 2022

The active ingredients of Napttegi Kong(GML, Glycine max landrace), a type of native rare soybeans, were identified, and an ultrasonic extraction method was introduced as an eco-friendly extraction method. Through the component analysis of the Napttegi Kong extract, the epicatechin, which was not found in conventional soybeans, was identified. For effective extraction using ultrasonic, the main extraction conditions were optimized using the response surface analysis method. Through the Box-Behnken design process, 15 experiments were conducted with the extraction temperature, the ratio of extraction solvent/solution, and extraction time as key independent variables. A quadratic regression equation for the two dependent variables, epicatechin content and total isoflavone content, was derived, and the coefficients of determination were found to be high as R² = 0.9939 and R² = 0.9844, respectively, confirming that the correlation showed high significance. The extraction conditions satisfying the maximum expectations of these two dependent variables were predicted. to be 40.4℃ of extraction temperature, 19.3 times of extraction solvent/solution, and 91 sec of extraction time. The expected value and the actual experimental value of the epikatechin content and the total isoflavone content were similar, so it was confirmed that this experimental method is a highly reliable optimization model.

• Economic and Environmental Geology
• /
• v.38 no.6 s.175
• /
• pp.657-662
• /
• 2005

Extractions fro fertilizer and soil samples were performed to yield the operationally defined fractions 'soluble' chromate (extractable with $NH_4NO_3$), 'exchangeable' chromate (extractable with phosphate buffer pH 7.2), and these results were compared with the data obtained by extractions with ammonium sulfate, borate buffer pH 7.2, saturated borax pH 9.6, and polyphosphate (Graham's salt). In order to maintain the pH of extractant solution about constant, the concentration of extractant buffer had to be raised to at least 0.5 M. The results strongly depended on the kind of extractant, and the solid: liquid ratio. For most of the samples investigated, the extraction efficiency increased in the order borate-sulfate-nitrate-phosphate. Whereas the recovery of $K_2CrO_4\;and\;CaCrO_4$ added to the samples of basic slags prior to the extraction was about complete, the recovery of added $PbCrO_4$ was highly variable. In soil extracts, the color reaction was interfered from co-extracted humics, which react with the chromate in weak acid solution during the time period necessary for color reaction (1 hour). However, this problem can be overcome by standard addition and subtraction of the color of the extractant solution. In soil extract of about pH < 7, organic material reduced chromate during the extraction period also, and standard addition of soluble chromate is recommended to prove recovery and the stability of chromate in the samples. In admixtures of soils and basic slags, results for hexavalent chromium were lower than from the mere basic slags. This effect was more pronounced in phosphate than in nitrate extracts. As a proficiency test, samples low in organic carbon from contaminated sites in Hungary were tested. The results from $NH_4NO_3$ extracts satisfactorily matched the results of the Hungarian labs obtained from $CalCl_2$ extractants.

• Korean Journal of Human Ecology
• /
• v.21 no.5
• /
• pp.989-1004
• /
• 2012

The purpose of this study was to investigate the characteristics of the pigment and the dyeability of juniperus chinensis needles, berry, bark and heartwood extracts using distilled water, methanol, normal butanol and ethyl acetate as a solvent. Ultraviolet-visible absorption spectrum bands of the extracts were measured at around 280nm to 320nm in all the solvent extracts. The maximum absorption wavelength was able to determine tannin. All the solvent extracts except for distilled water extracts were able to confirm the presence of chlorophyll. Infrared absorption spectra (FT-IR) of all parts of the extracts showed broad absorption bands of OH due to phenolic-OH, benzene CH peak of phenol chemical structure, ether-based stretching vibration peak and the peak of flavonoid compounds that appeared in all the solvent extracts. The yield of juniper needles and heartwood in distilled water and methanol extraction were effective. Extraction of berry yields in distilled water was also effective. The yield of ethanol extraction from the bark showed better efficiency. As a result of using distilled water for the dye solution, the color of the fabrics dyed with all extracts of the needles and Y series berries generally showed light Y progression with a strong red tinge. By using a mixture of 20% ethanol and 80% distilled water for the dye solution, the color of the fabrics dyed with needles and berry extracts showed Y series dominantly. The color of the fabrics dyed with Bark and heartwood extracts were dominantly R series.

• Resources Recycling
• /
• v.24 no.3
• /
• pp.3-10
• /
• 2015

A study has been made on the recovery & separation of cobalt and copper from organic acid leaching solution by solvent extraction. The experimental parameters such as the equilibrium pH, concentration of extractant and phase ratio were observed. Copper was extracted using LIX 84 and Cobalt was extracted using cyanex 272 and versatic acid 10. Experimental results showed that extraction percent of copper was 99% at above eq. pH 2.0 and then more than 90% of cobalt were extracted by cyanex 272 in eq. pH 6.0 and versatic acid 10 in eq. pH 7.5. Stripping of copper and cobalt from the loaded organic phases can be accomplished by sulfuric acid as a stripping reagent and 120 ~ 150 g/L of $H_2SO_4$ was effective for the stripping of copper and cobalt respectively. Finially, the basic optimal process for recovery of copper and cobalt from the bio-leaching solution was proposed.

• Resources Recycling
• /
• v.24 no.5
• /
• pp.56-62
• /
• 2015

Solvent extraction experiments for the separation and recovery of Re from hydrochloric acid leaching solution of spent super alloy by Alamine 304-1 were carried out. The effects of some variables, such as the nature and concentration of the extractants, HCl concentration, and the presence of impurities were investigated. The synthetic solutions of Re were prepared by dissolving ammonium perrhenate (APR), Alamine304-1, Cyanex272 and $D_2EHPA$ were used solvent extractants distilled in kerosene. The extraction percentage of Re by Alamine304-1 was higher than the other extractants as Cyanex272 and $D_2EHPA$ and the percentage is about 99%. Only 99% of Re was extracted in the presence of Al, Co and V in HCl solution.

• Resources Recycling
• /
• v.23 no.2
• /
• pp.37-45
• /
• 2014

Solvent extraction experiments have been performed to separate Nd and Pr from chloride leaching solution of monazite sand using single Cyanex272 and mixed extractants as PC88A+Cyanex272 and PC88A+TBP. For this purpose, the effect of the concentration of extractants on the extraction and separation of the two metals were studied by varying the pH of aqueous solution. In the experimental ranges conducted in this study, the distribution coefficients of Nd were higher than those of Pr. In Cyanex272 system, our results indicated that concentration of extractant and initial pH did not affect distribution coefficients, but separation factor was increased with increasing initial pH. In binary extractant system, distribution coefficients were lower than those of single PC88A system, whereas separation factor was similar in both mixed and single extractant system.

• Resources Recycling
• /
• v.23 no.5
• /
• pp.21-27
• /
• 2014

A study on the solvent extraction for the recovery of Li from lithium-containing waste solution was investigated using $D_2EHPA$ as an extractant. The experimental parameters, such as the pH of the aqueous solution, concentration of extractant and phase ratio were observed. Experimental results showed that the extraction percentage of Li was increased with increasing the equilibrium pH. More than 50% of Li was extracted in eq. pH 6.0 by 20% $D_2EHPA$. From the analysis of McCabe-Thiele diagram, 95% of Li was extracted by four extraction stage at phase ratio(O/A) of 3.0. Stripping of Li from the loaded organic phases can be accomplished by sulfuric acid as a stripping reagent and 90 ~ 120 g/L of $H_2SO_4$ was effective for the stripping of Li. Finially, Li was concentrated about 11.85 g/L by continuous stripping process, and then lithium carbonate was prepared by precipitation method.

• Korean Journal of Microbiology
• /
• v.36 no.1
• /
• pp.69-73
• /
• 2000

Arthrobacter sp. A-6 was cultivated and DFA III(di-fructofuranose dianhydride) was produced with inulin fructotransferase from the chicory root. The specific growth rate, yield of cell mass and yield of enzyme from the culture in variable chicory root extracts were studied and the results compared. Standard inulin solution(10%) was treated with the crude enzyme solution of inulin fructotransferase from the cell culture, 1.14mg/ml of DFA III was produced. The enzyme reactions were processed with various preparations of chicory root extracts in the same conditions. The highest yield of DFA III production(2.29 mg/ml) was obtained from the chicory roots without washing or extraction. The yield of DFA III from the washed chicory roots without extraction was at lowest(0.44 mg/ml). The production process of inulin fructotransferase and DFA III from the chicory root without prewashing or extraction steps were more efficient.

• Resources Recycling
• /
• v.14 no.2
• /
• pp.33-42
• /
• 2005

Solvent extraction experiments have been performed to separate Nd and Sm from chloride solution with PC88A. The effect of the saponification of PC88A on the extraction and separation of the two metals were studied. In the experimental ranges conducted in this study, the distribution coefficients of Sm were higher than those of Nd and separation factor between them increased with the equilibrium pH of aqueous solution. Saponification of PC88A enhanced the distribution coefficients of Sm and Nd and the separation factor. A chemical model was developed to predict the distribution coefficients of metals and separation factor from the initial extraction conditions. The measured distribution coefficients of Nd and Sm with PC88A and saponified PC88A agreed well with those calculated in this study.