• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2005.10a
• /
• pp.168-172
• /
• 2005

동일한 추출제가 함유된 3종의 추출레진을 대상으로 중희토류인 Gd의 추출특성을 비교하였다. 실험조건은 $20^{\circ}C$에서 평형 pH, Gd 농도, 추출시간으로 하여 다음과 같은 결과를 얻었다. 추출레진에서 추출시간 5분이내에 $Gd^{3+}$ 이온이 90%이상 추출되며, 추출시간 30분 이후에 변화가 거의 없어 추출반응이 종결된 것으로 판단된다. 평형 pH. 2.2이하에서 분배비는 평형 pH에 대해 선형적으로 감소하였다. Freundlich's 흡착등온식을 도입하여 3종의 추출레진에 대해 적용해 본 결과 결정계수$(R^2)$ 0.95이상으로 나와, Freundlich's 흡착등온식에 부합됨을 알 수 있었다.

• Korean Chemical Engineering Research
• /
• v.53 no.1
• /
• pp.39-45
• /
• 2015

We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity $Fe^{3+}$ solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of $Mg^{2+}$ and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-orewastewater treatments, as well as in the economic production of the nano-adsorbent.

• Korean Journal of Metals and Materials
• /
• v.47 no.5
• /
• pp.297-303
• /
• 2009

Solvent extraction experiments of cupric and cuprous chloride with Alamine336 have been performed from HCl solution. In order to identify the solvent extraction reaction, distribution diagram of cupric and cuprous species with HCl concentration was obtained by considering complex formation reaction and the activity coefficient of solutes with Pitzer equation. Analysis of the solvent extraction data by graphical method together with the distribution diagram of copper indicated that solvent extraction reaction of copper with Alamine336 depends on HCl concentration. In strong HCl solution of 3 and 5 M, ${CuCl_4}^{2-}$ and ${CuCl_3}^{2-}$ took part in the solvent extraction reaction as Cu(II) and Cu(I), respectively. When HCl concentration was 1 M, ${CuCl_2}^-$ was extracted into the organic phase in the case of Cu(I) while adduct formation between $Cu^{2+}$ and Alamine336 was responsible for the solvent extraction reaction of Cu(II).

• Resources Recycling
• /
• v.27 no.5
• /
• pp.69-76
• /
• 2018

For the purpose of optimizing the counter current extraction process for separation of [Sm] and [Pr, Nd] group in hydrochloric acid solution using Cyanex 572 as an extractant, the theory of Xu Guangxian was derived for calculating the optimized extraction factors. From the basic batch test result, the separation factor of [Sm]/[Pr, Nd] was 14.59 at pH 1.75 in extraction process and 14.61 at 0.01 M HCl in scrubbing process. The process parameters can be calculated using a theory of optimum extraction ratio. From the result of calculation, the total extraction and scrubbing stage numbers at counter current process were 11 and for maintain extraction ratio the flow rate ratio of feed solution, solvent solution, scrubbing solution was 6.25 : 1.74 : 5.80 using 0.1 M HCl.

• Natural Product Sciences
• /
• v.19 no.4
• /
• pp.303-310
• /
• 2013

Velvet deer antler (VDA) is well known oriental medicine claimed to have tonic activities as improving bone mineral density (BMD), immune-enhancing, rejuvenating and many other medicinal activities. Ossified deer antler (ODA) is bony product produced by over-calcification of deer antler due to late harvesting. The extraction efficiency of ODA by conventional boiling in water must be very poor due to bony nature, hence the reputations for the medicinal efficacies of ODA has been highly under-evaluated compared to that of VDA without any experimental evidences. Employing our new efficient water extraction process ($135^{\circ}C$), the extracts of ODA and VDA were analysed to compare the contents of bioactive components and the potencies of pharmacological activities. The results showed that; 1) The $135^{\circ}C$ extraction (autoclaving) of ODA gave highly increased amount of biomass, 120% more than the conventional extraction by 100-boiling, whereas the same treatment for VDA showed only 15% increased amount of biomass. 2) Feeding the ODA- or VDA-extracts to oophorectomized rats showed very potent BMD-recovering activity. 3) During the ossification of deer antler, the total collagen content was found to be increased by addition of type-1 to pre-existing type-2 collagen, but not replacement of type-2 to type-1 collagen. High titer of peptide hormones like growth hormone and IGF-1 were detected in the ODA- and VDA-extracts and also in the serum of ODA- or VDA-treated oophorectomized animals dose-dependently. Present experimental data will give a conclusion that folkloric poor reputations on ODA must be concerned only with poor extraction efficiency of conventional $100^{\circ}C$ water extraction and not based on the composition of bioactive substances of ODA.

• Korean Chemical Engineering Research
• /
• v.46 no.3
• /
• pp.512-515
• /
• 2008

The removal of iron from neodymium chloride solution was carried out by solvent extraction using Alamine 336 in kerosine. The effect of Alamine 336, hydrochloric acid and chloride ion concentrations on the extraction of Fe were studied. The results showed that Alamine 336 as an extractant for removal of iron was effective and the extraction percentage of iron was increased with increasing hydrochloric acid and chloride ion concentration in aqueous solution. The extraction of 99% of iron is attained at a ratio of A/O = 4 by distilled water. The stripping yield of iron from loaded Alamine 336 decreased with decreasing hydrochloric acid concentration in stripping solution.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2006.05a
• /
• pp.95-99
• /
• 2006

• Journal of the Mineralogical Society of Korea
• /
• v.26 no.2
• /
• pp.129-138
• /
• 2013

River bank filtration has been considered as a promising alternative water management scheme, in which groundwater is extracted from an aquifer near a river after infiltration of the river water into the aquifer, thereby improving and maintaining the quality of water recovered. Iron (Fe) associated with sediment in contact with groundwater and infiltrating surface water is an important factor in determining the quality of water recovered from the pumping wells in river bank filtration. This study reports the results of Fe speciation in the aquifer sediment samples collected from different depths at the river bank filtration site in Changwon, studied using four different chemical extraction methods, namely, ferrozine, oxalate, HCl, and DCB methods. Overall, the results show that Fe(II) as well as the total Fe content decreases with depth down to ~20 m and then increases further below. This trend is consistent with the redox characteristics suggested by visual observation. The silt/clay size fraction (${\phi}$ < 62.5 ${\mu}M$) has up to 2~10 times more Fe compared with the sand size fraction (62.5 ${\mu}M$ < ${\phi}$ < 2 mm), depending on the extraction method. Of the four extraction methods, DCB solution extracted the most Fe from the sediment samples. The amounts of Fe extracted by the different extraction methods can be a good indicator of the redox conditions along the depth of the aquifer.

• Resources Recycling
• /
• v.27 no.4
• /
• pp.50-56
• /
• 2018

For the purpose of optimizing the counter current extraction process for separation of [Pr, Nd, Sm] group and [La] in mixed solution using Cyanex 572 as an extractant, the theory of Xu Guangxian was derived for calculating the optimized extraction factors. From the basic batch test result, the separation factor was 16.80 at extraction process and 21.48 at scrubbing process, and the loading capacity of 1.0 M Cyanex 572 was 0.12 M of rare earth element. The process parameters such as the stage number at extraction and scrubbing process, the flow rate ratio of feed and solvent solution can be calculated using an equation of optimum extraction ratio proposed by Xu Guangxian. From the result of calculation, 7 extraction stages and 4 scrubbing stages were required for rare earth separation, and the flow rate ratio of feed solution, solvent solution, scrubbing solution was 25 : 5.67 : 12.27.

• Journal of the Korean Ceramic Society
• /
• v.31 no.11
• /
• pp.1401-1413
• /
• 1994

The synthesis of kaolinite mineral from domestic diatomite for silica resource, commercial vailable gibbsite or alumina for alumina resource were made under various hydrothermal treatment, and the sythetic effect of acidic mineralizers, temperature treatment with time duration, particle size of alumina on formation of kaolinite mineral and the plastic properties of synthesized kaolinite were investigated. The various acidic mineralizers which are HCl, HNO3, H2SO4 and Oxalic acid were employed for hydrothermal reaction in the range of 0.01 mol/ι to 2 mol/ι concentration of each mineralizers. It was found that HCl in the level of 1 mol/ι solution produced highly yields of well-crystallized and platy form kaolinite mineral and gave the most effective extraction of iron oxide, compared to that of others, that HNO3 produced highly yield of kaolinite but lower extraction of iron oxide, that H2SO4 produced low yield of kaolinite and formed alunite mineral, and that oxialic acid formed spherical crystalline kaolinite and gave low extraction of iron oxide. Moreover, it showed that kaolinite minerals were well synthesized in a wide range of less than 2 mol/ι acids, but were poorly synthesized at more than 2 mol/ι acids. However, boehmite and kaolinite were coexistently formed in the temperature range of 18$0^{\circ}C$ and 20$0^{\circ}C$ when the calcined diatomite and gibbsite were involved. The well-ordered kaolinite mineral as a platy form was highly synthesized in the temperature range of 220 and 24$0^{\circ}C$, when the same marterials as above were used with treatment of 1 mol/ι HCl solution. The results also revealed that the size of crystalline platy form kaolinite, synthesized from alumina and calcined diatomite with treatment in 1 mol/ιHCl solution at 24$0^{\circ}C$, was much larger than that of gibbsite and calcined diatomite shown previously, and that kaolinite and corundum minerals were coexistently formed under any hydrothermal treatment conditions. The plasticity of synthesized kaolinite from under 2 ${\mu}{\textrm}{m}$ alumina and calcined diatomite was very poor, and that of the synthesized kaolinite from raw diatomite and gibbsite gave higher than that of calcined diatomite and gibbsite.