K2CO3 첨가에 따른 H2S 제거용 무기계 흡착제의 흡착성능 영향에 관한 연구

장길남,송영상,홍지숙,유영우,황택성 한국청정기술학회 2017 청정기술 Vol.24 No.3

The goal of this paper was to improve the performance of the adsorbent to remove H2S. Pellet type adsorbents were prepared by using four kinds of materials (Fe2O3, Ca(OH)2, Activated carbon, Al(OH)2) for use as a basic carrier. As the results of H2S adsorption tests, Fe2O3 and Activated Carbon improved the adsorption performance of H2S by 1.5 ~ 2 times, and Ca(OH)2 and Al(OH)2 showed no effect on H2S adsorption performance. Four basic materials were as carriers, and 5 wt% of KI, KOH and K2CO3 were added on the carriers, respectively. As the results of H2S adsorption tests, adsorbent containing K2CO3 showed thebest performance. As a result of H2S adsorption test with varying K2CO3 content from 5 to 30 wt%, it was confirmed that adsorption performance was increased up to 20 wt% of K2CO3 and adsorption performance decreased to 30 wt%. The H2S adsorption performance was modeled by using Thomas model with varying K2CO3 contents and the results were used for the adsorption tower design. It was shown that the experimental values and the simulated values were in good agreement with the contents range of K2CO3 up to 20 wt%. Based on these results, it is expected that not only the adsorption performance of H2S adsorbent is improved but also life time of the adsorbent is increased. 본 연구는 악취가스 물질(바이오가스의 불순물)의 하나인 H2S를 제거하기 위한 흡착제의 성능을 향상시키기 위해 수행하였다. 기본 담체로서 4가지 물질(Fe2O3, Ca(OH)2, 분말 활성탄, Al(OH)3)을 혼합 사용하여 pellet 형태의 흡착제를 제조하였다. 또한, 4가지 물질의 H2S 흡착에 미치는 영향을 평가한 결과, Fe2O3와 분말활성탄은 H2S 흡착성능이 각각 1.5, 2배로 증가하는 것으로 나타났으며 Ca(OH)2와 Al(OH)2는 H2S 흡착성능에는 영향이 없는 것으로 나타났다. 또한 4가지 물질을 기본혼합 담체로 한 후, 활성물질로 KI, KOH, K2CO3를 선정하여 각각 5 wt% 첨가한 후에 H2S 흡착성능을 시험한 결과 K2CO3를 첨가한 흡착제가 가장 성능이 우수한 것으로 나타났다. 또한 K2CO3를 5 ~ 30 wt%까지 변화시키면서 흡착성능을 확인한 결과, K2CO3 함량이 20 wt%까지는 함량과 비례하여 H2S 흡착성능이 증가하는 것을 확인할 수 있었으나 30 wt%에서는 H2S 흡착성능 급격히 떨어지는 것을 확인하였다. 또한 K2CO3 첨가 함량에 따른 H2S 흡착성능을 바탕으로 Thomas model을 이용하여모델링을 실시한 결과에서도 K2CO3 함량이 20 wt%까지는 실험값과 모사값이 잘 일치하고 있음을 보여주었다. 이러한 결과들을 바탕으로, 본 연구에서 확인된 활성물질의 종류와 활성물질의 함량을 흡착제 제조에 이용한다면 H2S 흡착제의 흡착성능 개선뿐만 아니라 흡착제의 사용수명 증대를 기대할 수 있었다.

H₂S 독성가스감지기가 필요한 정량적 공정설비 기준 및 비상시 안전을 위한 위치선정 방안에 대한 연구

최재영(Jae-Young Choi),권정환(Jung-Hwan Kwon) 한국가스학회 2018 한국가스학회지 Vol.22 No.2

천연가스 및 석유를 정제 및 가공하는 화공플랜트에서 원료에 함유된 황화수소(H₂S)의 누출로 인한 피해를 최소화시키기 위한 설계 기법들이 세계적으로 널리 연구되어왔다. 그러나 국내에서는 화공플랜트에서 H₂S 가스 피해 최소화를 위한 별도의 뚜렷한 설계 지침 및 규제가 없는 실정이다. 그러므로 본 연구는 H₂S 독성가스감지기를 설치해야 할 공정설비의 H₂S 가스 함량의 정량적 기준을 500 ppm으로 제시하고 타당한 근거를 설명하였다. 또한 ALOHA 프로그램을 사용하여 과거 H₂S 가스 누출 사고를 재구성하여 IDLH 값인 100 ppm까지의 확산 반경을 산출하였다. 모델링의 기상 조건은 국내 3대 석유화학단지가 위치한 울산, 여수, 대산의 조건을 각각 적용하였으며, 울산, 대산, 여수 순서로 긴 반경이 도출되었다. 비상시 안전을 위해서 본 연구에서 얻은 H₂S 가스의 100 ppm까지의 확산 반경을 고려한 추가적인 H₂S 독성가스감지기가 설치되어야 하고, 이때는 반드시 지역별 기후조건이 고려되어야 할 것이다. Design techniques for minimizing the damage caused by leakage of H₂S gas, contained in natural gas and petroleum, have been widely studied abroad in chemical plants that purify and process natural gas and petroleum. However, there is no domestic engineering practice and regulation of H₂S. In accordance with the circumstances, this study proposes the quantitative criteria of process equipment to install H₂S toxic gas detector as 500 ppm and explains the valid basis. The H₂S gas dispersion radius up to IDLH 100 ppm is calculated by ALOHA under previous H₂S gas leak accident scenario. The weather conditions of modeling include the conditions of Ulsan, Yeosu and Daesan, the three major petrochemical complexes in Korea. The long radius up to 100 ppm was derived in order of Ulsan, Daesan, Yeosu. For emergency safety the dispersion radius up to 100 ppm of the H₂S gas obtained in this study should be extended to apply the additional H2S toxic gas detector, and local climate conditions should be considered.

H₂S 독성가스감지기가 필요한 정량적 공정설비 기준 및 비상시 안전을 위한 위치선정 방안에 대한 연구

최재영,권정환,Choi, Jae-Young,Kwon, Jung-Hwan 한국가스학회 2018 한국가스학회지 Vol.22 No.2

Design techniques for minimizing the damage caused by leakage of $H_2S$ gas, contained in natural gas and petroleum, have been widely studied abroad in chemical plants that purify and process natural gas and petroleum. However, there is no domestic engineering practice and regulation of $H_2S$. In accordance with the circumstances, this study proposes the quantitative criteria of process equipment to install $H_2S$ toxic gas detector as 500 ppm and explains the valid basis. The $H_2S$ gas dispersion radius up to IDLH 100 ppm is calculated by ALOHA under previous $H_2S$ gas leak accident scenario. The weather conditions of modeling include the conditions of Ulsan, Yeosu and Daesan, the three major petrochemical complexes in Korea. The long radius up to 100 ppm was derived in order of Ulsan, Daesan, Yeosu. For emergency safety the dispersion radius up to 100 ppm of the $H_2S$ gas obtained in this study should be extended to apply the additional $H_2S$ toxic gas detector, and local climate conditions should be considered. 천연가스 및 석유를 정제 및 가공하는 화공플랜트에서 원료에 함유된 황화수소($H_2S$)의 누출로 인한 피해를 최소화시키기 위한 설계 기법들이 세계적으로 널리 연구되어왔다. 그러나 국내에서는 화공플랜트에서 $H_2S$ 가스 피해 최소화를 위한 별도의 뚜렷한 설계 지침 및 규제가 없는 실정이다. 그러므로 본 연구는 $H_2S$ 독성가스감지기를 설치해야 할 공정설비의 $H_2S$ 가스 함량의 정량적 기준을 500 ppm으로 제시하고 타당한 근거를 설명하였다. 또한 ALOHA 프로그램을 사용하여 과거 $H_2S$ 가스 누출 사고를 재구성하여 IDLH 값인 100 ppm까지의 확산 반경을 산출하였다. 모델링의 기상 조건은 국내 3대 석유화학단지가 위치한 울산, 여수, 대산의 조건을 각각 적용하였으며, 울산, 대산, 여수 순서로 긴 반경이 도출되었다. 비상시 안전을 위해서 본 연구에서 얻은 $H_2S$ 가스의 100 ppm까지의 확산 반경을 고려한 추가적인 $H_2S$ 독성가스감지기가 설치되어야 하고, 이때는 반드시 지역별 기후조건이 고려되어야 할 것이다.

나노 크기 칼슘-실리케이트-하이드레이트(C-S-H) 결정이 시멘트 수화에 미치는 영향 분석

김경태,우수지,유성원,최영철 한국건설순환자원학회 2023 한국건설순환자원학회 논문집 Vol.11 No.2

In this study, nano-sized C-S-H crystals were synthesized using the liquid phase reaction method and their properties were investigated. The synthesized C-S-H crystals were added to the cement composite in suspension form to determine their effect on the hydration properties of the cement. The amount of chemical admixture was varied to obtain nano-sized C-S-H crystals with optimal agglomerated morphology, and SEM photographs were analyzed. A cleaning process was added to remove h armful s ubstances other than t he s ynthesiz ed C -S-H c rystals. I t was found that t he c oncentration of h armful substances was reduced in the case of C-S-H crystals subjected to the cleaning process. The synthesized C-S-H suspensions were prepared with and without the cleaning process, and cement composites were prepared with the cement weight content as the main variable. The effect of C-S-H crystals on the initial hydration properties of the cement was confirmed by microhydration heat analysis. In addition, mortar specimens were prepared to measure the compressive strength over time. The test results showed that the nano-sized C-S-H crystals act as nucleation sites in the cement paste to promote the early hydration of the cement and increase the early compressive strength. 본 연구에서는 액상반응법을 이용하여 나노 크기의 C-S-H 결정을 합성하고 그 특성을 조사하였다. 합성한 C-S-H 결정을현탁액 형태로 시멘트 복합체에 첨가하여 시멘트의 수화특성에 미치는 영향을 확인하였다. 최적 응집 형태의 나노 크기C-S-H 결정을 도출하기 위해 화학혼화제의 양을 변수로 제조하였으며, SEM 사진 분석을 하였다. 합성된 C-S-H 결정외유해물질을 제거하기 위해 세척 과정을 추가하였다. 세척과정을 거친 C-S-H 결정의 경우 유해물질의 농도가 낮아짐을 확인하였다. 합성된 C-S-H 현탁액은 세척 과정 유무에 따라 제조하였으며, 시멘트 중량대비 함유량을 주요 변수로 하여 시멘트복합체를 제조하였다. 미소수화열 분석을 통해 C-S-H 결정이 시멘트의 초기 수화특성에 미치는 영향을 확인하였다. 또한, 모르타르 시험체를 제작하여 시간에 따른 압축강도를 측정하였다. 실험결과 나노 크기의 C-S-H 결정이 시멘트 페이스트내에서 핵 생성처 역할을 하여 시멘트의 초기 수화를 촉진시키며, 초기 압축강도 또한 증가하는 것을 확인하였다.

Biocompatible silica nanoparticles conjugated with azidocoumarin for trace level detection and visualization of endogenous H₂S in PC3 cells

Rajalakshmi, Kanagaraj,Nam, Yun-Sik,Youg, Sumin,Selvaraj, Muthusamy,Lee, Kang-Bong Elsevier 2018 Sensors and actuators. B Chemical Vol.259 No.-

<P><B>Abstract</B></P> <P>The silica nanoparticles (SiO<SUB>2</SUB>NPs) conjugated with azidocoumarin (Cy-N<SUB>3</SUB>) was applied for the selective and sensitive H<SUB>2</SUB>S detection, even when H<SUB>2</SUB>S was present in 1000-fold excess of other bio thiols and ions. In the silica nanoprobes, azide in the Cy-N<SUB>3</SUB> group acted as the recognition element, and the probe was biocompatible. The nanoprobe displayed blue emission at 456 nm and excitation at 367 nm. After introducing H<SUB>2</SUB>S into the probe solution, the fluorescent intensity at 456 nm increased linearly as a function of H<SUB>2</SUB>S concentration (correlation coefficient, 0.9970), and the limit of detection was 6 nM. The enhanced fluorescent emission intensity was due to H<SUB>2</SUB>S-mediated reduction of the electron-withdrawing azide into electron-donating amine. The SiO<SUB>2</SUB>NPs@Cy-N<SUB>3</SUB> and its reaction products with H<SUB>2</SUB>S (SiO<SUB>2</SUB>NPs@Cy-NH<SUB>2</SUB>) were characterized by <SUP>1</SUP>H NMR and TEM. The probe also showed low cytotoxicity and could trace endogenous H<SUB>2</SUB>S in physiological pH. We therefore then successfully utilized it to detect H<SUB>2</SUB>S in living PC3 cells. The probe was also successfully employed for detection of H<SUB>2</SUB>S gas using Whatman papers coated with SiO<SUB>2</SUB>NPs@Cy-N<SUB>3</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Biocompatible chemosensor for H<SUB>2</SUB>S detection was developed using silica nanoparticles. </LI> <LI> H<SUB>2</SUB>S detection was achieved even in 1000-fold excess of other interferents. </LI> <LI> The lowest LOD was 6 nM under physiological conditions. </LI> <LI> The probe was successfully applied for H<SUB>2</SUB>S detection in live PC3 cells. </LI> <LI> The paper strip probe coated with silica nanoparticles successfully detected H<SUB>2</SUB>S. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

K<SUB>2</SUB>CO<SUB>3</SUB> 첨가에 따른 H<SUB>2</SUB>S 제거용 무기계 흡착제의 흡착성능 영향에 관한 연구

장길남(Kil Nam Jang),송영상(Young Sang Song),홍지숙(Ji Sook Hong),유영우(Young-Woo You),황택성(Taek Sung Hwang) 한국청정기술학회 2017 청정기술 Vol.23 No.3

본 연구는 악취가스 물질(바이오가스의 불순물)의 하나인 H2S를 제거하기 위한 흡착제의 성능을 향상시키기 위해 수행하였다. 기본 담체로서 4가지 물질(Fe2O3, Ca(OH)2, 분말 활성탄, Al(OH)3)을 혼합 사용하여 pellet 형태의 흡착제를 제조하였다. 또한, 4가지 물질의 H2S 흡착에 미치는 영향을 평가한 결과, Fe2O3와 분말활성탄은 H2S 흡착성능이 각각 1.5, 2배로 증가하는 것으로 나타났으며 Ca(OH)2와 Al(OH)2는 H2S 흡착성능에는 영향이 없는 것으로 나타났다. 또한 4가지 물질을 기본혼합 담체로 한 후, 활성물질로 KI, KOH, K2CO3를 선정하여 각각 5 wt% 첨가한 후에 H2S 흡착성능을 시험한 결과 K2CO3를 첨가한 흡착제가 가장 성능이 우수한 것으로 나타났다. 또한 K2CO3를 5 ~ 30 wt%까지 변화시키면서 흡착성능을 확인한 결과, K2CO3 함량이 20 wt%까지는 함량과 비례하여 H2S 흡착성능이 증가하는 것을 확인할 수 있었으나 30 wt%에서는 H2S 흡착성능 급격히 떨어지는 것을 확인하였다. 또한 K2CO3 첨가 함량에 따른 H2S 흡착성능을 바탕으로 Thomas model을 이용하여 모델링을 실시한 결과에서도 K2CO3 함량이 20 wt%까지는 실험값과 모사값이 잘 일치하고 있음을 보여주었다. 이러한 결과들을 바탕으로, 본 연구에서 확인된 활성물질의 종류와 활성물질의 함량을 흡착제 제조에 이용한다면 H2S 흡착제의 흡착성능 개선뿐만 아니라 흡착제의 사용수명 증대를 기대할 수 있었다. The goal of this paper was to improve the performance of the adsorbent to remove H2S. Pellet type adsorbents were prepared by using four kinds of materials (Fe2O3, Ca(OH)2, Activated carbon, Al(OH)2) for use as a basic carrier. As the results of H2S adsorption tests, Fe2O3 and Activated Carbon improved the adsorption performance of H2S by 1.5 ~ 2 times, and Ca(OH)2 and Al(OH)2 showed no effect on H2S adsorption performance. Four basic materials were as carriers, and 5 wt% of KI, KOH and K2CO3 were added on the carriers, respectively. As the results of H2S adsorption tests, adsorbent containing K2CO3 showed the best performance. As a result of H2S adsorption test with varying K2CO3 content from 5 to 30 wt%, it was confirmed that adsorption performance was increased up to 20 wt% of K2CO3 and adsorption performance decreased to 30 wt%. The H2S adsorption performance was modeled by using Thomas model with varying K2CO3 contents and the results were used for the adsorption tower design. It was shown that the experimental values and the simulated values were in good agreement with the contents range of K2CO3 up to 20 wt%. Based on these results, it is expected that not only the adsorption performance of H2S adsorbent is improved but also life time of the adsorbent is increased.

스마트폰 비즈니스의 구성요인이 고객만족과 고객충성도에 미치는 영향

이중배(Joong-Bae Lee),백동현(Dong-Hyun Baek) 한국전자거래학회 2017 한국전자거래학회지 Vol.22 No.2

스마트폰 비즈니스 환경이 H/W 중심에서 S/W 경쟁으로 변화하고 있고 기업의 경쟁기반도 H/W에서 서비스로 패러다임이 변화하고 있다. 이에 본 연구에서는 스마트폰 비즈니스 구성요인을 H/W, S/W, 통신서비스로 구성하였다. 본 연구의 목적은 비니지스 구성요인이 고객만족과 고객충성도에 미치는 영향관계를 파악하고, 전환비용이 고객충성도에 미치는 영향을 분석하는 것이다. 연구분석 결과, 고객 만족에 유의한 영향을 미치는 요인은 H/W 요인임이 밝혀졌고, S/W 요인과 통신서비스는 영향을 미치지 않는 것으로 확인되었다. 고객층성도에 영향을 미치는 요인은 H/W 요인과 S/W 요인임이 입증되고 통신서비스는 영향을 미치지 않는 것으로 분석되었다. 고객만족이 H/W 요인과 고객충성 간에 매개역할을 하는 것으로 나타났다. 전환비용은 선행연구와 동일하게 고객충성도에 유의한 영향을 미치는 것으로 분석되었다. 본 연구가 기존의 연구와의 차별점은 기존의 연구가 H/W, S/W, 통신서비스를 각각 나누어 분석하였으나, 본 연구에서는 H/W, S/W, 통신서비스의 통합된 3차원이 고객만족과 고객충성도에 미치는 영향을 규명하였다는데 의의가 있다. 본 연구 결과는 학술적, 실무적으로 성장이 정체된 스마트폰 산업에 시사점을 제공할 수 있으리라 본다. The core of the smartphone business environment is changing from H/W to S/W and with it the paradigm of an enterprise’s base of competition is changing from H/W to service. In accordance with this paradigm, in this study we have determined H/W, S/W and telecommunication service as smartphone business factors. The purpose of this study is to first analyze the influence business factors has on consumer satisfaction and customer loyalty. Secondly, to analyze the influence switching cost has on customer loyalty. As a result, the factor that has a notable influence on customer satisfaction turned out to be the H/W factor. On the other hand S/W factor and communication service turned out to have very little influence. In addition, the factors influencing customer loyalty turned out to be H/W factor and S/W factor. Telecommunication service did not have much of an influence. Customer satisfaction turned out to act as mediation effect between H/W factor and customer loyalty. Like the result of other preceding researches, switching cost turned out to have a significant influence on customer loyalty. This study differs from other studies in that while other existing studies analyzed H/W, S/W and communication service separately, this study analyzed the influence H/W, S/W and communication service as a whole has on customer satisfaction and customer loyalty. We speculate that the results of this study would provide some insight both in an academic and practical level for stagnant smartphone industry.

CONTROLL OF HYDROGEN SULFIDE GENERATION OCCURED IN LANDFILL SITES BY EXERTING OXYDIZING AGENTS

( Toshihiro Takeshita ),( Sotaro Higuchi ),( Masataka Hanashima ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.1

Although the generation of hydrogen sulfide, H₂S, in landfill sites often occurs throughout Japan, the practically applicable methods for controlling H₂S generation are very few. Hence, the effective method for solving the issue should be urgently developed. For the purpose of dealing with this matter we made use of the oxidizing agents such as hydrogen peroxide, H₂O₂, and bleaching powder, its principal ingredient was calcium hypochlorite, Ca(ClO)₂. We found out that the use of the chemicals effectively degraded H₂S as mentioned later in the results. Experiments were carried out in a 300 ml silicone-plug fitted conical flask containing a 200 ml of the leachate in which H₂S was dissolved. Then the headspace gas was taken out and the H₂S concentration was analyzed by GC-FPD. When 0.2 ml of H₂O₂, its concentration was certified up to 31%, was added, the H₂S concentration rapidly decreased and finally no H₂S was detected in 20 minutes. In this experiment, the initial concentration of H₂S in the headspace was ca. 200 ppm. In addition, when 0.2 ml of the solution containing 1.0 mg/L of Fe²⁺ was added concomitant with 0.2 nil of H₂O₂, the time for H₂S disappearance was shorten by ca. 5 minutes as compared to the result obtained without adding Fe²⁺. The effect of the addition of bleaching powder on H₂S degradation was next investigated. In the case of the addition of 20 mg of bleaching powder, the H₂S concentration could reach to the undetectable level in 4 minutes. No volatile chlorinated organic compound was detected in this treatment as far as the headspace gas was analyzed by GC-ECD. From the results obtained in the experiments, we concluded that the H₂S gas could be effectively degraded by the treatment of H₂O₂ or bleaching powder when appropriate amount of the chemicals were exerted. Finally, in order to find out the causal organic substances refer to the generation of H₂S in landfill sites, we selected the chemicals used in the materials. When 20 mg of the identified organic material that belong to admixture for cement or mortar, plasticizer and monomer for plastics and raw material for rubbers was added in a conical flask containing a 200 ml leachate and incubated at 35°C.

Gadolinium-Doped CeO2 Gas Sensor for H2S Sensing

진창현,Sangwoo Kim,김동응,Ali Mirzaei,Jong Wook Roh,최선우,최명식 대한금속·재료학회 2023 대한금속·재료학회지 Vol.61 No.6

Dihydrogen sulfide (H2S) gas has a flammable nature and is one of the most toxic and dangerousgases. Even small concentrations can be fatal to humans. Herein, we investigated the H2S gas-sensingfeatures of commercial pristine cerium oxide (CeO2) and gadolinium (Gd)-doped CeO2 (GDC) nanoparticles. First, the sensing materials were well-characterized using various methods including X-ray photoelectronspectroscopy, transmission electron microscopy and X-ray diffraction to gain insight into their chemicalcomposition, morphology, phases, and crystallinity, respectively. In the next step, gas sensors were fabricatedusing a top electrode (Au/Ti) configuration. Preliminary H2S-gas-sensing studies revealed that GDC gas sensorhad a superior gas response to H2S gas than the pristine CeO2 gas sensor at 350°C. The responses of thepristine CeO2 gas sensor to 20 ppm H2S gas was 1.542, while the response of the GDC gas sensor to theaforementioned H2S concentration was 3.489. In addition, the GDC sensor exhibited good selectivity to H2Sgas among C2H5OH, C7H8 and NH3 gases. Also, we investigated the response of the sensor in up to 60%relative humidity. The enhanced response of the GDC gas sensor to H2S gas was mainly related to theformation of oxygen defects as a result of Gd-doping in CeO2. Also, good selectivity to H2S was related to thesensing temperature, the higher reactivity of H2S relative to other gases and the small bond energy of H-SH. This study demonstrates the promising ability of Gd-doping to enhance the H2S gas-sensing characteristicsof CeO2, which can be applied to other similar systems based on semiconducting metal oxides.

H₂O/N₂/H₂S 혼합가스 분위기 900℃에서 캐스타블 내화물의 부식

신민,윤종원,김창삼,Shin, Min,Yoon, Jong-Won,Kim, Chang-Sam 한국결정성장학회 2017 한국결정성장학회지 Vol.27 No.2

저급탄을 가스화하는 반응기에 사용되는 내화물은 고온에서 부식성이 강한 $H_2S$ 가스에 노출되며, 경도나 내마모성과 같은 기계적 특성이 가스에 노출되는 시간이 길어짐에 따라서 떨어진다. 그러나 $H_2S$ 가스에 의한 내화물의 기계적 특성 약화 원인이 아직 잘 알려져 있지 않다. 본 실험에서는 내화도가 다른 두 종류의 케스터블 내화물을 $H_2S$ 농도가 높은 $H_2O/N_2/H_2S$ 혼합가스에 100시간 동안 $900^{\circ}C$에서 노출시키고, 미세구조, 결정상과 내마모 특성 변화를 비교하였다. 혼합가스에 노출되면서 내화물 시편의 무게는 감소하였다. 노출 후 기공률은 감소하고, 내마모 특성은 현저하게 떨어졌다. 부식에 의해서 내화물을 구성하는 상에 변화가 일어났는데, $CaAl_2O_4$와 일부의 $SiO_2$는 사라지고 $CaSO_4{\cdot}2H_2OS$와 $Al_2Si_2O_5(OH)_4$ 상이 나타났다. 내화물의 내마모 특성이 $H_2S$ 가스에 노출된 후에 감소하는 주 원인은 캐스터블 내화물에서 결합제 역할을 하는 $CaAl_2O_4$가 사라지고 기계적 특성이 나쁜 $CaSO_4{\cdot}2H_2OS$가 생성되기 때문인 것으로 생각되었다. Refractories used in low-rank coal gasification reactors are usually exposed in a highly corrosive $H_2S$ gas at less than $1000^{\circ}C$, and their mechanical properties such as erosion resistance and fracture strength decline with the exposure time. However, the cause of the degradation of the mechanical properties has little reported yet. In this paper, two kinds of castable refractories with different refractoriness had been exposed in a $H_2O/N_2/H_2S$ mixed gas with high $H_2S$ content for 100 hours at $900^{\circ}C$, and the changes of microstructure, crystalline phases and erosion resistance were compared before and after the corrosion test. The weight of the refractories decreases due to the elution of silica in the specimens after the corrosion test. The capillary porosities of the samples are reduced, but the erosion resistance of the samples is fatally weakened after the corrosion test. There also are changes in constituent phases; dmitryivanovite ($CaAl_2O_4$) and amorphous silica ($SiO_2$) disappear, and gypsum ($CaSO_4{\cdot}2H_2OS$) and kaolinite ($Al_2Si_2O_5(OH)_4$) newly appear after the corrosion test. It is obvious that the phase change from dmitryivanovite that works as a binding agent in the castable refractory to gypsum is the main reason of the degradation of the erosion resistance, because the mechanical properties of gypsum are much poorer than those of dmitryivanovite.