• Title/Summary/Keyword: Hydrochloric acid

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Caustic Soda Decomposition and Leaching of Monazite in Hong-Cheon Area Deposit. (홍천산 모나자이트의 가성소다 분해 및 침출)

  • Kim Joon-Soo;Yoon Ho-Sung;Kim Sung-Don;Kim Chul-Joo;Lee Jin-Young
    • Resources Recycling
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    • v.13 no.4
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    • pp.11-16
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    • 2004
  • In this study, treatment conditions for monazite concentrate in Hong-Cheon area deposit were studied with NaOH fritting decomposition and HCl leaching experiments. At condition of NaOH fritting decomposition, it was appropriate to adopt particle size of -200 mesh monazite, reaction temperature of about $460^{\circ}C$ and NaOH/TREO mole ratio of 6. In case of HCl leaching for decomposed product, it was appropriate to use hydrochloric acid of above 8N with leaching temperature of above $80^{\circ}C$, leaching time of 2 hrs and pulp density of about 10%. A rate of decomposition and leaching for monazite was above 90% under optimum conditions. Sodium phosphate compound was effectively recovered from NaOH decomposed solution, and mixed rare earth chloride solution was prepared with HCl leaching of decomposed product.

Fabrication of EPDM Rubber/Organo-bentonite Composites: Influence of Hydrochloric Acid on the Characteristics of Modified Bentonite and Final Products (EPDM 고무/유기 벤토나이트 복합체의 제조: 개질된 벤토나이트와 최종 생성물의 특성에 대한 염산의 영향)

  • Ge, Xin;Li, Mei-Chun;Cho, Ur Ryong
    • Polymer(Korea)
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    • v.38 no.1
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    • pp.62-68
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    • 2014
  • To improve the compatibility of bentonite with rubber matrix, organo-modified bentonite was synthesized with a silane coupling agent, [3-(2-aminoethylamino)propyl]trimethoxysilane (AEAPTMS) in the suspension of bentonite. The structure and characteristics of organo-modified bentonite were investigated using FTIR-spectroscopy, thermogravimetric analysis (TGA) and X-ray diffraction (XRD). Ethylene-propylene-diene monomer (EPDM) rubber/organo-bentonite composites were compounded by a two-roll mill. The vulcanization and mechanical properties were studied. Results showed that the concentration of hydrochloric acid and $H_2O$ in the synthesis had significant influence on the modification of bentonite, which further contributed to the properties of the composites. Filled with 20 phr modified bentonite, the tensile strength and elongation at break of the rubber increased from 1.95 to 4.8 MPa and 300% to 500%, respectively.

A Study on the Cation Extraction and Separation in Cement Industrial By-products for Applications to the Carbonation Process (탄산화 공정 적용을 위한 시멘트 산업부산물 내 양이온 추출 및 분리 연구)

  • Lee, Ye Hwan;Han, Dong Hee;Lee, Sang Moon;Eom, Han Ki;Kim, Sung Su
    • Applied Chemistry for Engineering
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    • v.30 no.1
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    • pp.34-38
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    • 2019
  • A cement industrial by-product was used as a Ca source for the carbonation process. It was confirmed that the most of cement industrial by-products was composed of CaO and KCl through ICP and XRD analyses. The optimal extractant type and concentration was 1.5 M of hydrochloric acid, and the solid/liquid ratio was 0.1 g/mL. It was assumed that the cation extraction efficiency was dependent of the pair ions and their binding formation and also the solubility from extraction efficiency results by varing extractants. After extraction process, it was also confirmed that the cation could be selectively separated from the solution with respect to the kind of additives and the injection order. When NaOH was injected into the solution to control pH values ranging from 9.5 and 13, impurities and $Ca(OH)_2$ were precipitated, whereas the separated K ion was precipitated in the form of KCl under the injected $C_2H_5OH$.

Leaching of Smelting Reduced Metallic Alloy of Spent Lithium Ion Batteries by the Mixture of Hydrochloric Acid and H2O2 (과산화수소를 혼합한 염산용액으로 폐리튬이온배터리의 용융환원된 금속합금의 침출)

  • Moon, Hyun Seung;Tran, Thanh Tuan;Lee, Man Seung
    • 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℃.

Direct Preparation of Dichloropropanol from Glycerol over Acetin Catalyst (아세틴 촉매상에서 글리세롤로부터 디클로로프로판올의 직접 제조)

  • Song, Sun-Ho;Park, Dong-Ryul;Woo, Sung-Yul;Song, Won-Seob;Kwon, Myong-Suk;Song, In-Kyu
    • Clean Technology
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    • v.15 no.1
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    • pp.42-46
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    • 2009
  • Solvent-free direct preparation of dichloropropanol (DCP) from glycerol (by-product of bio-diesel production) and hydrochloric acid gas was carried out over acetin catalyst in a gas-liquid batch reactor. For this purpose, acetin mixture and triacetin were used as a homogeneous acetin catalyst. Performance in the acetin-catalyzed reaction was compared to that in the non-catalytic reaction under the same reaction conditions ($110^{\circ}C$, 3 bar, 3 h). Conversion of glycerol in the acetin-catalyzed reactions was ca. 3% higher than that in the non-catalytic reaction, and selectivity for dichloropropanol in the acetin-catalyzed reactions was ca. 50% higher than that in the non-catalytic reaction. It was also revealed that the catalytic performance of triacetin was ca. 2% higher than that of acetic mixture.

Corrosion Inhibition Performance of Two Ketene Dithioacetal Derivatives for Stainless Steel in Hydrochloric Acid Solution

  • Lemallem, Salah Eddine;Fiala, Abdelali;Ladouani, Hayet Brahim;Allal, Hamza
    • Journal of Electrochemical Science and Technology
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    • v.13 no.2
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    • pp.237-253
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    • 2022
  • The methyl 2-(1,3-dithietan -2- ylidene)-3-oxobutanoate (MDYO) and 2-(1,3-dithietan-2-ylidene) cyclohexane -1,3-dione (DYCD) were synthesized and tested at various concentrations as corrosion inhibitors for 316L stainless steel in 1 M HCl using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface analysis techniques (SEM / EDX and Raman spectroscopy) and Functional Density Theory (DFT) was also used to calculate quantum parameters. The obtained results indicated that the inhibition efficiency of MDYO and DYCD increases with their concentration, and the highest value of corrosion inhibition efficiency was determined in the range of concentrations investigated (0.01 × 10-3 - 10-3 M). Polarization curves (Tafel extrapolation) showed that both compounds act as mixed-type inhibitors in 1M HCl solutions. Electrochemical impedance spectra (Nyquist plots) are characterized by a capacitive loop observed at high frequencies, and another small inductive loop near low frequencies. The thermodynamic data of adsorption of the two compounds on the stainless steel surface and the activation energies were determined and then discussed. Analysis of experimental results shows that MDYO and DYCD inhibitors adsorb to the metal surface according to the Langmuir model and the mechanism of adsorption of both inhibitors involves physisorption. SEM-EDX results confirm the existence of an inhibitor protective film on the stainless steel surface. The results derived from theoretical calculations supported the experimental observation.

Deterioration Properties of Shotcrete as Tunnel Supporter was Exposed to Harmful Ions (터널 지보용 숏크리트의 유해이온에 대한 열화특성)

  • Jung, Ho-Seop;Kim, Dong-Gyou
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.5
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    • pp.55-64
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    • 2008
  • Shotcrete have become a deterioration which was exposed to harmful environments. In this study, in order to evaluate the deterioration properties of shotcrete, visual examination, compressive strength, adhesive strength, microstructural analysis were investigated up to the 60th weeks of exposure. The attack solutions for test are sodium sulfate and hydrochloric acid solution with different concentrations, respectively. From the results, although the compressive strength of shotcrete specimens and the adhesive strength between specimens and rocks were high at the early immersion age, they rapidly dropped in the subsequent phases, especially in 5% sodium sulfate and pH1 hydrochloric acid solution. With continued exposure, various harmful ions penetrated into the shotcrete specimen, reacted with the cement hydrate, and generated expansion substances. It was verified that the shotcrete specimens suffered a serious deterioration by chemical attack.

Synthesis of CHBM-DVB Ion Exchanger and It's Ion Exchange Behavior (CHBM-DVB 이온교환체의 합성과 그의 이온교환작용)

  • Dong Won Kim;Kong Soo Kim;Nam Kee Lee
    • Journal of the Korean Chemical Society
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    • v.29 no.2
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    • pp.164-171
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    • 1985
  • The salicylic acid-formaldehyde condensed copolymer (SAF) and the 3-carboxy-4-hydroxy benzyl methacrylate divinylbenzene copolymer (CHBM-DVB) were synthesized. The capacities of SAF and CHBM-DVB ion exchangers were 4.6meq/g and 3.9 meq/g, respectively. The adsorption of several heavy metal ions on these weakly acidic ion exchangers and the property of ion exchanger were discussed. The distribution coefficients in hydrochloric acid solution and the elution behavior of several heavy metal ions were also discussed.

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Indirect Spectrophotometric Determination of Trace Quantities of Hydrazine

  • Haji Shabani, A.M.;Dadfarnia, S.;Dehghan, K.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.213-215
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    • 2004
  • An indirect, sensitive and accurate method for the determination of trace amounts of hydrazine is described. The method is based on the oxidation of hydrazine by a known excess of iodate in the presence of hydrochloric acid. The unreacted iodate is used in the oxidation of hydroxylamine to nitrite. Sulfanilic acid is diazotized by the nitrite formed. The resulting diazonium ion is coupled with N-(1-naphthyl)ethylenediamine to form a stable azo dye, which shows an absorption maximum at 540 nm. Hydrazine can be determined in the range of 20-400 ng $mL^{-1}$ with a detection limit of 3.1 ng $mL^{-1}$. The relative standard deviation for 50, 200 and 400 ng $mL^{-1}$ of hydrazine is 2, 1.5 and 1.3%, respectively (n = 10). The method was applied to the determination of hydrazine in water samples.

Studies on Isolative Determination of dl- Methylephedrine hydrochloride from Complex Preparation (복합제제(複合製劑) 성분중(成分中) dl-Methylephedrine hydrochloride의 분리정량(分離定量))

  • Kim, Byung-Hi;Yong, Jae-Ick
    • Journal of Pharmaceutical Investigation
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    • v.3 no.1_2
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    • pp.5-15
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    • 1973
  • Fluorometric determination of dl-Methylephedrine hydrochloride from complex preparation were studied. According to the experimental results and considerations obtained the results for the following. (1) dl-Methylephedrine hydrochloride in Hydrochloric acid media occurs the fluorescens by Picrolonic acid and Cuppric acetate. (2) The maximum absorption fluorescence wave length of dl-Methylephedrine hydrochloride standard solution is $365m{\mu}$. (3) The relationship between the fluorescence proportions to concentration of standard solution at range of $4.2{\times}10^{-4}\;M$. $6{\times}10^{-4}M$. (4) dl-Methylephedrine hydrochloride was precisely determined even in the presence of various components, especially Chloropheniramine maleate, Dextromethorphan hydrobromide and Diphenylhydramine hydrochloride. (5) This method has high sensitivity and is simple in precedure. (6) This method be applicable with 99.79% accuracy and was 99.5% in complex preparation.

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