• Resources Recycling
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• v.9 no.3
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• pp.29-36
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• 2000

A study on the recovery of gallium from leaching solutions is carried out by solvent extraction in order to produce gallium oxide of high purity. The results show that the extraction of gallium is found to be increase with acidities of aqueous solution up to 7.4 M/L when pure isopropyl ether is used. And the extraction of iron also increases with increasing acidity of aqueous solution. It appears that the separation of gallium from iron cannot be satisfactorily accomplished with isopropyl ether. But, in the case of extaction with D2EHPA, almost complete extraction of iron is achieved-leaving all the gallium in the aqueous solution-by maintaining the acidity of aqueous solution at 2 M/L. Accordingly, $Ga_2O_3{\cdot}H_2O$ of more than 99wt.% in purity can be produced from zinc residues through the processes comprising of alkali leaching, precipitation by neutralization and solvent extraction using isopropyl ether and D2EHPA as extractants.

• Resources Recycling
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• v.19 no.6
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• pp.70-76
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• 2010

It was to investigate the optimum leaching conditions for the NaOH hot digestion and hydrochloric acid leaching of Monazite. The optimum condition for NaOH hot digestion was that the concentration of NaOH/TREO mole ratio was 15, the temperature of decomposition $140^{\circ}C$, and reaction time 2 hrs. And the optimum condition for the hydrochloric acid leaching of NaOH hot digestion product was that the concentration of hydrochloric acid was 6N, leaching time 2 hrs and pulp density about 15%. The yield of rare earth oxide was above 90% on the above experimental condition.

• Resources Recycling
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• v.30 no.2
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• pp.24-30
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• 2021

Dismantling tests were performed to separate components from waste printed circuit boards (PCBs) using HCl solution with Sn4+. Then, the effects of agitation speed, reaction temperature, initial Sn4+ concentration, and HCl concentration on the dismantling of components were investigated. No significant effect on the dismantling speed was observed upon changing the agitation speed from 100 to 300 rpm. However, the dismantling rate increased with increasing reaction temperature, Sn4+ concentration, and HCl concentration. In the all-component dismantling tests, when the dismantling ratio increased to 100%, no solder was observed on the boards, and the Sn4+ concentration was ~1,500 mg/L. The dismantling ratio of the components from the PCB increased to 100% within 2 h when 1 mol/L HCl solution with 10,000 mg/L Sn4+ was used at an agitation speed and temperature of 200 rpm and 90 ℃, respectively.

• Resources Recycling
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• v.30 no.5
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• pp.25-31
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• 2021

Smelting reduction of spent lithium-ion batteries results in the production of metallic alloys in which reduced cobalt, nickel and copper coexist. In this study, we investigated the leaching of the metallic alloys containing the above three metals together with iron, manganese, and silicon. The mixture of hydrochloric acid and hydrogen peroxide as an oxidizing agent was employed, and the effect of the concentration thereof, the reaction time and temperature, and pulp density was investigated to accomplish the complete leaching of cobalt, nickel, and copper. The effect of the hydrogen peroxide concentration and pulp density on the leaching was prominent, compared to that of reaction time and temperature, especially in the range of 20 to 80℃. The complete leaching of the metals present in metallic alloys, except silicon, was accomplished using 2 M HCl and 5% H₂O₂ with a pulp density of 30 g/L for 150 min at 60℃.

• Resources Recycling
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• v.31 no.3
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• pp.73-80
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• 2022

Reduction smelting of spent lithium-ion batteries at high temperature produces metallic alloys. Following solvent extraction of the leaching solutions of these metallic alloys with either sulfuric or hydrochloric acid, the raffinate is found to contain Ni(II), Co(II), Mn(II), and Si(IV). In this study, two cationic exchange resins (Diphonix and P204) were employed to investigate the loading behavior of these ions from synthetic sulfate and chloride solutions. Experimental results showed that Ni(II), Co(II), and Mn(II) could be selectively loaded onto the Diphonix resin from a sulfate solution of pH 3.0. With a chloride solution of pH 6.0, Mn(II) was selectively loaded onto the P204 resin, leaving Ni(II) and Si(IV) in the effluent. Elution experiments with H₂SO₄ and/or HCl resulted in the complete recovery of metal ions from the loaded resin.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.183-184
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• 2003

어류를 채란채정, 표지, 계측 및 수술하기 위하여 공기 중에서 취급할 때 받는 스트레스를 최소화하기 위해서나, 일정 용기로 다량의 어류를 장시간에 걸쳐 효율적으로 운반하기 위하여 마취는 매우 중요시 된다. 본 연구는 쥐노래미 Hexagrammos otakii (Jordan and Starks)의 공기중에서의 효과적인 취급과 쥐노래미를 대상으로 한 양식생물학적 연구시 간편한 취급을 위하여, 쥐노래미를 대상으로 인체에 무해하여 안전성이 높은 염산리도카인-중탄산나트륨(lidocaine HCl/NaHCO$_3$)을 사용시 그 수온별 마취 효과를 조사하였으며, 일정 마취수온에서의 염산리도카인-중탄산나트륨과 MS-222(methanesulfonate)의 마취 효과를 비교 평가하였다. (중략)

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.147-155
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• 2004

Freeze dried antler, heat dried antler, antler were extracted through processing step by water, protease and hydrochloric acid(HCl). Extraction rate of freeze dried antler at 50$^{\circ}C$ by water was 9.01％(8.82, absorbance at 280 nm), that of heat dried antler was 9.01％(4.45, absorbance at 280 nm), and that of antler was 1.10％(0.31, absorbance at 280 nm), respectively. Extraction rate of freeze dried antler by bacterial protease was 16.89％(4.50, absorbance at 280 nm), and that of heat dried antler was 17.29％(5.62, absorbance at 280 nm), and that of antler was 18.22％(0.64, absorbance at 280 nm), respectively. Extraction rate of freeze dried antler by 0.8N HCl was 72.25％(4.60, absorbance at 280 nm), that of heat dried antler was 71.14％(4.70 absorbance at 280 nm), and that of antler was 79.82％ (2.80, absorbance at 280 nm), respectively. Extraction rate of freeze dried antler through three processing steps was 98.15％, that of heat dried antler was 97.35％, that of antler was 99.14％, respectively. The result of analysis by HPLC shows that high molecular pe which appears in young antler and antler extraction was changed into a small molecular peak of about 1,000 by the reaction of protease, and protein of about MW 70,000 was extracted from their remaining residue by 0.8N HCl. The above result shows that water extraction and protease extraction in the freeze dried young antler, protease extraction and HCl extraction in dried young antler, and HCl extraction in antler are most effective.

• Resources Recycling
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• v.19 no.5
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• pp.25-30
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• 2010

Leaching of CMSX-4 superalloy was done in hydrochloric acid solutions. The leaching behaviors of main alloy components, such as Ni, Co, Cr, Al, was investigated by controlling acid concentration, temperature, leaching time and pulp density. Increasing acid concentration enhanced the leaching rate till the rate decreased over 3 M acid concentration. Raising temperature increased the leaching amount of the metal components. After the leaching for 60 minutes at $90^{\circ}C$ and 10 g/L pulp density in 4 M acid solution, 93.2% nickel, 89.9% aluminum, 80.4% cobalt, and 79.1% chromium were leached. Nickel and aluminum were preferentially leached out, while the leaching rate of cobalt and chromium were relatively high only after 60 minutes, Increasing pulp density lowered the leaching rate and especially serious on cobalt and chromium, The optimum leaching condition for CMSX-4 was obtained at $90^{\circ}C$, 120 minutes, and less than 125 g/L in 4 M hydrochloric acid solution.

• Resources Recycling
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• v.27 no.6
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• pp.53-58
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• 2018

Solvent extraction of Li(I) from weak HCl solution was investigated by the mixture of TBP/MIBK with other neutral extractants such as Cyanex 923, TOPO and TOP. The TBP/MIBK organic phase was loaded with 0.1 M $FeCl_3$ at different HCl concentrations (1-9 M). Extraction of Li(I) from weak HCl solution is related to the stability of $FeCl_3$ in the organic mixture. As HCl concentration increased in preparing the loaded TBP phase, the stripping percentage of Fe(III) during the extraction of Li(I) became reduced and thus Li(I) could be extracted by ion exchange reaction with hydrogen ion in the organic. The concentration of TBP in the extractant mixture affected the stability of $FeCl_3$. Compared to TBP, Fe(III) was easily stripped from the loaded MIBK and thus no Li(I) was extracted by the mixture with MIBK. The nature of neutral extractant with TBP/MIBK showed little difference in the extraction of Li(I) and stripping of Fe(III).

• YAKHAK HOEJI
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• v.7 no.2_3
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• pp.36-41
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• 1963

Cobalt thiocyanate ion에 미치는 영향을 연구하였다. Cobalt ion이 $NH_{4}CNS$ 용액에 의해서 생성되는 ion의 색의 transmittance는 확산에 의하여 적어지며, 황산존재하에서는 황산의 양과 Transmittance 사이에 비례적 관계가 있다. 염산 및 질산도 역시 Transmittance의 값에 영향을 미치기는 하나 염산의 경과에는 이 착 ion이 황산존재하보다 다소 불안정하며 질산에 의해서는 안정화가 극히 적어서 단시간내에 Perthiocyanuric acid로 인정되는 물질로 분해한다. 또한 그 Transmittance가 과량의 광산존재하에서 적어지는 현상으로 부터 $Co(SCN)^{2-n/_{$ n/의 n의 값이 커지는 것은 ether에 이행하는 SCN-을 Volhard 씨법으로 정량함으로서 확증하였다.