• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.1078-1091
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• 1994

Thermodynamic calculations have been made from existing literature data to show that it is reasonable to expect to recover metal chlorides from the chlorination of metal sulfides with chlorine gas. The reactions between 12 metal sulfides, such as, $Ag_2S$, $As_2S_3$, CdS, CuS, $Cu_2S$, FeS, HgS, $MoS_2$, $Ni_3S_2$, PbS, $Sb_2S_3$ and chlorine gas were investigated by means of thermogravimetric method. The theorical calculation and the experimental investigation showed that chlorination of sulfide is a better alternative process for the extraction metallurgical process of sulfide ores.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.132-136
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• 1992

The effects of chlorine treatment on the lipid composition of wheat flour were studied by treating flour with different amounts (1, 2 and 4 ounces per 100 pounds of flour) of liquidized chlorine gas. The contents of free lipid increased slightly while those of the bound lipid decreased at all levels of chlorine used. The contents of neutral lipid in the free lipid decreased while those in the bound lipid increased as the level of chlorine increased. The contents of triglycerides in the free and bound lipids decreased as the level of chlorine increased. As the level of chlorine increased, digalactosyl diglycerides in the bound lipid decreased, whereas those in the free lipid increased within the range of 1 to 2 oz of chlorine. The phosphatidylcholine content in the free and bound lipids decreased while the lysophosphatidylcholine increased in both free and bound lipids as the level of chlorine increased. The content of saturated fatty acids increased while that of unsaturated ones decreased as the level of chlorine increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.601-604
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• 2009

This study was conducted to examine the effect of aqueous chlorine dioxide treatment as a washing method on removal of pesticide residues. Three pesticides of chlorpyrifos, diazinon, and metalaxyl, which are commonly used in vegetable crops, were treated with 10, 50, and 100 ppm of aqueous chlorine dioxide and decomposition of the pesticides was determined using gas chromatography. Three pesticides used in this study were decomposed by aqueous chlorine dioxide treatment and removal rate was proportional to treatment time as well as concentration of aqueous chlorine dioxide. In particular, 100 ppm of aqueous chlorine dioxide treatment decreased the pesticides efficiently. In addition, lettuce was treated by dipping in distilled water and 100 ppm aqueous chlorine dioxide, respectively, and was compared regarding removal efficiency of the pesticides. The results revealed that washing with 100 ppm aqueous chlorine dioxide for 10 min was the most effective for removing the pesticides. These results suggest that aqueous chlorine dioxide can be used as a washing method of fresh produce to remove the residual of pesticides.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.816-823
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• 1996

Chlorine containing high density plasmas are widely used to etch various materials in the microelectronic device fabrication. In this study, the characteristics of inductively coupled $Cl_2(O_2/N_2$) plasmas and their effects on the formation of silicon etching have been investigated using a Langmuir probe, quadrupole mass spectrometry(QMS), X-ray photoelectron spectroscopy(XPS), and Scanning Electron Microscopy(SEM). The addition of oxygen for chlorine plasmas reduced ion current densities and chlorine radical densities compared to the nitrogen addition by the recombination of oxygen with chlorine. Also, when silicon is etched in $Cl_2/O_2$ plasmas, etch products recombined with oxygen such as $SiCl_xO_y$ emerged. However, when nitrogen is added to chlorine, etch products recombined with nitrogen or Si-N bondings on the etched silicon surface were not found. All the silicon etch characteristics were dependent on the plasma conditions such as ion density, radical density, etc. As a result sub micron vertical silicon trench etch profiles could be effectively formed using optimized etch conditions for $Cl_2/O_2\; and \;Cl_2/N_2$ gas combinations.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.65-65
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• 1999

Dry etching technique provides more easy controllability on the etch profile such as anisotropic etching than wet etching process and the results of lots of researches on the characterization of various plasmas or ion beams for semiconductor etching have been reported. Chlorine-based plasmas or chlorine ion beam have been often used to etch several semiconductor materials, in particular Si-based materials. We have studied the effect of He flow rate on the Si and SiO2 dry etching using chlorine-based plasma. Experiments were performed using reactive ion etching system. RF power was 300W. Cl2 gas flow rate was fixed at 58.6 sccm, and the He flow rate was varied from 0 to 120 sccm. Fig. 1 presents the etch depth of si layer versus the etching time at various He flow rate. In case of low He flow rate, the etch rate was measured to be negligible for both Si and SiO2. As the He flow increases over 30% of the total inlet gas flow, the plasma state becomes stable and the etch rate starts to increase. In high Ge flow rate (over 60%), the relation between the etch depth and the time was observed to be nearly linear. Fig. 2 presents the variation of the etch rate depending on the He flow rate. The etch rate increases linearly with He flow rate. The results of this preliminary study show that Cl2/He mixture plasma is good candidate for the controllable si dry etching.

• 한국연소학회:학술대회논문집
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• 2001.11a
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• pp.137-141
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• 2001

The behavior of Cl is important to prevent HCl exhausted by incineration of RDF. Because RDF is composed of municipal wastes, its calorific value is very various. Thus components of RDF are to be analyzed and elemental analyze and calorific value are to be done. And in order to find the behavior of Cl during RDF combustion, Cl included in exhaust gas and ash is captured and analyzed. RDF which made by municipal and $Ca(OH)_2$ with regular ratio(Ca/0.5Cl) is incinerated in fluidized bed combustor. Cl included in exhaust gas and fly ash is captured and analyzed. Finally the change of Cl concentration included in exhaust gas and ash is analyzed and the behavior of Cl is investigated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.74-78
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• 2003

The structural property of phenolic and non-phenolic lignin has an effect on the reaction rate of lignin by oxygen and chlorine dioxide respectively. Moreover, the undesirable degradation of cellulose followed by lignin degradation is influenced by chemical charge and reaction time. In this paper, several lignin model compounds were used to illuminate the interaction of oxygen and chlorine dioxide by varying the position of O and D(OD, DO, ODO and DOD), and gas chromatography method was used to investigate the degradation of lignin by determining the content of methoxyl groups in lignin. It was shown that structural properties of lignin models were more influential on the degradation and demethylation of lignin than the above combination. Combination of oxygen and chlorine dioxide, however, was more effective in degradation of lignin than only one stage, and three stages than two stages.

• Food Science and Preservation
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• v.30 no.2
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• pp.190-204
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• 2023

Because of their short harvest season, large quantities of persimmons must often be processed within a limited time. Therefore, new methods to extend their storage life are required. This study examined the effects of chlorine dioxide (ClO₂) gas fumigation for various treatment periods on the storage quality of astringent persimmons Cheongdobansi under low-temperature conditions. The conditions consisted of continuous treatment with ClO₂, treatment for 2 weeks with ClO₂, and no treatment, all of which are stored at low temperatures. Control samples (storage 0 days) without any treatment were prepared and all experiments were conducted for 10 weeks at two-week intervals. The ClO₂ gas treatment maintained the moisture content, color value, hardness, soluble tannin content, and sensory characteristics. However, ClO₂ gas treatment did not affect the soluble solids, pH, and total sugar content. In particular, continuous treatment with ClO₂ maintained the storage quality after 6-8 weeks of storage, particularly the hardness and weakness (sensory evaluation). The results suggest the potential of continuous treatment with ClO₂ as a highly effective method for maintaining the freshness of Cheongdobansi.

• Korean Journal of Environmental Agriculture
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• v.1 no.1
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• pp.53-58
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• 1982

A study was carried out to examine the effects of chlorine and hydrogen chloride gas with various concentrations (0.1, 0.25, 0.5 and $1.0\;g/m^3/hr)$ on rice and soybean plants. Symptoms, ratios of destroyed leaf, grain yield and chlorophyll contents in leaves were investigated. The results are as follows. 1) Hydrogen chloride gas damaged the margine parts of rice and soybean leaves, but chlorine appeared grayish subtle spots in whole parts of rice and soybean leaves. 2) Rice leaves showed higher damage ratio in hydrogen chloride fumigation than in soybean leaves, but less damage in chlorine. 3) Chlorophyll contents in rice leaves were higher in chlorine gas fumigated than hydrogen chloride fumigated. 4) The ratio of destroyed leaf was negatively correlated with chlorophyll contents.

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.1-5
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• 2017

In the event of toxic gas accidents, soil deposition is a main factor which has an effect on extent of the damage. In this study, it presents the influence of soil deposition properties according to the change of soil depth and the organic matter contents in soil. In this experimentation, the soil deposition device developed in Air Force Research Laboratory in USA is recreated. The tested samples of mixing soil have each value of the organic matter contents. After a variety of synthetic soil were exposed to constant Cl2 concentration, the chlorinity is measured using an anion exchange chromatography(ICS-1100) to quantify the mount of deposition. As the results, the increase of soil depth causes an decreased soil deposition and the increase of exposure time causes an increased soil deposition in surface. Also, the increase of soil deposition mainly depended on the organic matter contents in surface.