Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Preparation of Calcium Sulfate Hemihydrate Using Stainless Steel Refinery Sludge and Waste Sulfuric Acid
In this study, calcium sulfate(gypsum) powder was obtained using waste sulfuric acid and stainless steel refinery sludge by-produced from chemical reagent and the iron industry, by the neutralization of waste sulfuric acid. As variables for the experiment, the molar ratio of the H2SO4: Ca(OH)2, the pH, the reaction temperature and time, the amount of catalyst were used. The crystal shape and microstructure of obtained powder were observed by XRD and SEM, and the thermal property was investigated by DTA. As the NaCl is added 0–20 wt.% as a catalyst to the H2SO4-Ca(OH)2 system, it can be found that the crystal shape goes through the processes as follows; gypsum dehydrate gypsum → gypsum hemihydrate + gypsum dihydrate → gypsum hemihydrate. And gypsum hemihydrate is δ-type as the result of DTA. As waste sulfuric acid and stainless steel refinery sludge were used, the pH of reacted solution (which was 0.8) was rapidly raised up to 8–9 by the addition of stainless steel sludge and gypsum dihydrate was produced as a by-product. Therefore, it was found that stainless steel refinery sludge is sufficiently applicable for the neutralization of waste sulfuric acid.
Preparation of Calcium Sulfate Hemihydrate Using Stainless Steel Refinery Sludge and Waste Sulfuric Acid
In this study, calcium sulfate(gypsum) powder was obtained using waste sulfuric acid and stainless steel refinery sludge by-produced from chemical reagent and the iron industry, by the neutralization of waste sulfuric acid. As variables for the experiment, the molar ratio of the H2SO4: Ca(OH)2, the pH, the reaction temperature and time, the amount of catalyst were used. The crystal shape and microstructure of obtained powder were observed by XRD and SEM, and the thermal property was investigated by DTA. As the NaCl is added 0–20 wt.% as a catalyst to the H2SO4-Ca(OH)2 system, it can be found that the crystal shape goes through the processes as follows; gypsum dehydrate gypsum → gypsum hemihydrate + gypsum dihydrate → gypsum hemihydrate. And gypsum hemihydrate is δ-type as the result of DTA. As waste sulfuric acid and stainless steel refinery sludge were used, the pH of reacted solution (which was 0.8) was rapidly raised up to 8–9 by the addition of stainless steel sludge and gypsum dihydrate was produced as a by-product. Therefore, it was found that stainless steel refinery sludge is sufficiently applicable for the neutralization of waste sulfuric acid.
Preparation of Calcium Sulfate Hemihydrate Using Stainless Steel Refinery Sludge and Waste Sulfuric Acid
Ahn, Ji Whan (Autor:in) / Eun, Hee Tai (Autor:in) / Kim, Hyung Seok (Autor:in) / Kim, Jang Su (Autor:in) / Sung, Ghee Woong (Autor:in)
Geosystem Engineering ; 4 ; 71-76
01.09.2001
6 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Unbekannt
Alpha calcium sulfate hemihydrate and preparation method thereof
| Europäisches Patentamt | 2021
Process for producing calcium sulfate by using waste sulfuric acid
| Europäisches Patentamt | 2021
Calcium sulfate hemihydrate activated low heat sulfate resistant cement
| Online Contents | 2002