• Resources Recycling
• /
• v.20 no.6
• /
• pp.28-36
• /
• 2011

The adsorption of nickel(Ni) from sulfuric acid solution was carried out by ion exchange method. A series of batch tests in synthetic solutions were carried out using Lewatit Monoplus TP 220 resin. The following experimental parameters, such as temperature, shaking rate, reaction time, pH, resin dosage and concentration of nickel ions etc. were investigated to establish the effective optimum conditions of nickel adsorption. The solution pH(2.0~5.0) and shaking rate had little effects on the adsorption of nickel and adsorption time of 72hours was required to reach equilibrium. The experimental results show a good agreement with Feundlich isotherm and pseudo-second order reaction. The adsorption behavior of Ni obtained from synthetic solution was compared with that of waste electroplating solution. Elution of nickel from loaded resin increased with increase in $H_2SO_4$ concentration.

• Journal of the Mineralogical Society of Korea
• /
• v.23 no.3
• /
• pp.183-189
• /
• 2010

It is of importance to separate Ni(II) and Co(II) from Mg(II) in solution which was leached from nickel laterite ore. In order to investigate the possibility of separating Ni(II) and Co(II) from Mg(II), adsorption behavior of the three metals from individual and mixed sulfate solutions was investigated by using Diphonix resin. The concentration of each metal in solution was fixed at 100 ppm and the pH of the sulfuric acid solution was changed from 5 to 7. At ambient temperature, the adsorption behavior of the three metal ions followed Langmuir adsorption isotherm. The loading capacity of Diphonix resin for the three metal ions was obtained from the Langmuir isotherm. Since adsorption behavior of the three metal ions from the mixed solution was similar to each other, it was found to be difficult to separate Ni(II) and Co(II) from Mg(II) by using Diphonix resin.

• Resources Recycling
• /
• v.30 no.2
• /
• pp.31-38
• /
• 2021

To investigate the separation of La(III) from sulfuric acid solutions containing Fe(III), rare earth double salt precipitation experiments were performed by adding sodium sulfate. In this work, the effect of sodium sulfate, Fe(III), and La(III) concentrations; reaction temperature; and time was investigated. The extent of precipitation of La(III) was proportional to the concentrations of Na+ and SO42- in the solution. As the reaction temperature increased to 100 ℃, the extent of precipitation of La(III) increased. The extent of precipitation of Fe(III) decreased with increasing reaction time. The concentration ratio of Fe(III) to La(III) did not have a significant effect on the precipitation of La(III). Our results indicate that it is possible to separate La(III) from a ferric sulfate solution through selective precipitation by adding sodium sulfate.

• Resources Recycling
• /
• v.31 no.1
• /
• pp.12-20
• /
• 2022

The smelting reduction of spent lithium-ion batteries results in metallic alloys containing Co, Cu, Fe, Mn, Ni, and Si. A process to separate metal ions from the sulfuric acid leaching solution of these metallic alloys has been reported. In this process, ionic liquids are employed to separate Fe(III) and Cu(II). In this study, D2EHPA and Cyanex 301 were employed to replace these ionic liquids. Fe(III) and Cu(II) from the sulfate solution were sequentially extracted using 0.5 M D2EHPA with three stages of cross-current and 0.3 M Cyanex 301. The stripping of Fe(III) and Cu(II) from the loaded phases was performed using 50% (v/v) and 60% (v/v) aqua regia solutions, respectively. The mass balance results from this process indicated that the recovery and purity percentages of the metals were greater than 99%.

• Resources Recycling
• /
• v.31 no.1
• /
• pp.21-28
• /
• 2022

The smelting reduction of spent lithium-ion batteries results in metallic alloys of cobalt, nickel, and copper. To develop a process to separate the metallic alloys, leaching of the metallic mixtures of these three metals with H₂SO₄ solution containing 3% H₂O₂ dissolved all the cobalt and nickel, together with 9.6% of the copper. Cyanex 301 selectively extracted Cu(II) from the leaching solution, and copper ions were completely stripped with 30% aqua regia. Selective extraction of Co(II) from a Cu(II)-free raffinate was possible using the ionic liquid ALi-SCN. Three-stage cross-current stripping of the loaded ALi-SCN by a 15% NH₃ solution resulted in the complete stripping of Co(II). A process was proposed to separate the three metal ions from the sulfuric acid leaching solutions of metallic mixtures by employing solvent extraction.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.40 no.4
• /
• pp.16-26
• /
• 2008

It is of great importance to decrease sheet break at the size press to enhance the runnability of today's high speed paper machines. To achieve this purpose it is required to control the penetration of the starch solutions at the size press. Use of ASA sizing system provides diverse advantages in improving machine runnability since it allows us to get rapid sizing development at the size press. Domestic paper industries, however, has not enjoyed these benefits of ASA sizing system mainly because of the poor efficiency of domestic corn starches used for ASA emulsification. To improve the emulsion stability and ASA sizing efficiency, it has been pointed out that new cationic starches are needed. In this study two methods of starch modifications, i.e. esterfication of cationic corn starch with OSA (Octenyl Succinic Anhydride), and acid hydrolysis by sulfuric acid were employed as methods to improve ASA sizing efficiency. The effect of these modification was compared with conventional cationic starches.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.6
• /
• pp.209-215
• /
• 2015

Following the semiconductor industry's growing, various types of toxic gases and caustic chemicals, HF(Hydrofluoric acid), HCI (Hydochloric acid), $H_2O_2$ (Hydrogen peroxide), $H_2SO_4$ (Sulfuric acid), and Piranha, were using on the semiconductor manufacturing process. Therefore many gas leakage accidents that produce huge losses of lives were caused by the processes. This research deeply considers two basic solutions that the necessity of MSDS education on university for reducing damage of lives and protecting life from chemical leak accidents such as a HF accident in Gumi, Korea and the use of GHS, REACH and the comprehension of propriety about using MSDS for keeping safety from conflagrations by released poison chemical materials.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.1
• /
• pp.110-123
• /
• 2019

This work was conducted to examine the relationship between lignin content and the durability of larch (LAR) pellets. LAR sawdust was immersed in tap water (TW), sulfuric acid (AC) and sodium hydroxide (AK) solutions, and then the immersed sawdust was used for pellet fabrication. Klason lignin (KL) content of the immersed LAR, contents of soluble lignin (SL) and monomeric sugars liberated from the immersion of LAR, and durability of LAR pellets were measured. KL content decreased as the concentration of AC and AK solutions increased, but glucose content increased with increase in AC and AK concentration. Durability of wood pellets fabricated using non-immersed LAR sawdust was the highest, followed by those made using TW-, AK- and AC-immersed sawdust. LAR pellets became more durable as the concentration of KL and SL increased, but a significant positive correlation was found only between pellet durability and KL content. Through the fluorescent microscopic observation and SEM-EDX analysis, it was verified that lignin content of non-immersed LAR pellets was higher than that of AC- and AK-immersed LAR pellets. These results suggest that lignin might contribute to an increase in inter-particle bonding in wood pellets.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.3
• /
• pp.47-53
• /
• 1998

The polyimide film surface was modified with KOH aqueous solutions or sulfuric acid. The film thickness was increased by about 10% through the modification of film surface. Hydrolysis of amide bonds and hydration of water induced the increase. The polarity of the film surface increased and identified by contact angle measurement. The depth and roughness of modified was increased. After treatment of surface with water, alkyl and 4-pentyloxyaniline were introduced on the film surface by complex formation between anionic species formed on the imide surface and ammonium ion. The newly introduced alkyl group was identified by FT-IR spectroscopy. Surface polarity reduced dramatically and the roughness was increased after introduction of ammonium salt.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.459-462
• /
• 2000

The pretreatment of used newspaper for the enzymatic digestion preprocess was performed on a percolation reactor and a batch reactor. The test condition of percolation process was $170^{circ}C$, 60min, 1 mL/min, and 400psi, that of batch was $40^{circ}C$, 3hr. and latm Reaction solutions used in pretreatment process were aqueous ammonia, sulfuric acid, water, and hydrogen-peroxide as an oxidizing agent. As a result, the effect of pretreatment was similar to batch and percolation process, but the yield of enzymatic hydrolysis was higher in batch than percolation. This batch pretreatment enhanced enzymatic hydrolysis rate and increased glucose yield from about 15 to 20%. The inhibition factors influenced the rate of enzymatic hydrolysis was investigated, and the ink contented newspaper was the major factor.