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題名 | 高嶺石與滑石熟料對堇青石之生成熱行為影響=Thermal Behavior of Cordierite Formation Affected by Calcined Kaolinite and Talc Powders |
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作者 | 范馨文; 林逸歆; 顏富士; 郭明錦; 林逸歆; | 書刊名 | 臺灣鑛業 |
卷期 | 71:1 2019.03[民108.03] |
頁次 | 頁1-11 |
分類號 | 458.6 |
關鍵詞 | 堇青石; 高嶺石; 滑石; 熟料; 固態反應法; Cordierite; Kaolinite; Talc; Calcined powder; Solid-state reaction; |
語文 | 中文(Chinese) |
中文摘要 | 以分別於700℃及900℃煆燒過的高嶺石與滑石熟料、與氧化鋁粉末依堇青石化學式計量混合作成配方,粉末混合均勻後,在1,135℃至1,350℃溫度作熱處理,瞭解以固態反應法(Solid State Reaction)合成堇青石時採用熟料原料的特點。主要訊息透過DTA及XRD分析技術對熱處理試樣所作測試取得。研究發現熟料最大的功能在於可提供較高活性的非晶質氧化矽。對700℃及900℃二溫度所獲得之熟料,前者呈現較高活性SiO_2的效果。此活性氧化矽在熱反應初期,即可與由高嶺石及滑石熟料轉換來的富鋁紅柱石及頑火輝石快速結合生成β-堇青石。此一過程因消耗SiO_2形成缺SiO_2環境,而使富鋁紅柱石及頑火輝石的反應改變為產生尖晶石及放出活性SiO_2。此SiO_2顯然在1,250℃與Al_2O_3反應生成富鋁紅柱石,而使整體反應重回初期熱合成堇青石的環境,重複生成堇青石及尖晶石與活性SiO_2,而此時堇青石極可能為α-相,尖晶石則與前1,200℃出現者一起於1,350℃與SiO_2反應生成α-堇青石。 |
英文摘要 | Kaolinite and talc powders that calcined at 700℃ and 900℃, respectively were mixed with alumina powders in the stoichiometric composition of cordierite. The mixtures then were thermal treated at temperatures ranging from 1,135℃to 1,350℃ to examine the characteristics of cordierite formation via solid state reaction using different calcined powders. Experiments results were analysized mainly by DTA and XRD. It is found that the basic function provided by the calcined powders in synthesizing cordierite was possibly introducing amorphous, or more precisely higher active state silica, especially from kaolinite calcined at 700℃. The silica was easier to react with mullite and enstatite to form β-cordierite firstly. And because the reaction consumes SiO_2, a SiO_2-lean environment will result in, leading to form spinel +SiO_2 from the reaction between mullite and enstatite. The temperature will be above 1,200℃. The reaction brings about the presence of active silica again that subsequently reacts with alumina to form mullite. It is obvious that the mineral assembly mullite-enstatite now is similar to that at 1,000℃ or lower, except the induced cordierite formation from mullite and enstatite now is α-phase instead. Moreover, the spinel generated will react with SiO_2, combined with that formed earlier above 1,200℃, to form α-cordierite at ~1,350℃. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。