磷酸鹽分解鉬酸鈣的熱力學

張剛; 趙中偉; 曹才放; 黃少波

doi:10.13374/j.issn1001-053x.2009.11.029

磷酸鹽分解鉬酸鈣的熱力學

doi: 10.13374/j.issn1001-053x.2009.11.029

張剛^1,2,3,
趙中偉^1,2,
曹才放^1,2,
黃少波^1,2

1. 中南大學冶金科學與工程學院, 長沙 410083;
2. 稀有金屬冶金與材料制備湖南省重點實驗室, 長沙 410083;
3. 湖南航天管理局高新材料與裝備技術研發中心, 長沙 410205

基金項目:

國家高技術研究發展計劃資助項目(No.2006AA06Z122)

湖南省國土資源廳礦產資源與合理開發利用科研專項計劃資助項目(No.2006K06)

詳細信息

作者簡介:
張剛(1979-),男,博士研究生;趙中偉(1966-),男,教授,博士生導師,E-mail:zhaozw@mail.csu.edu.cn

中圖分類號: TF841.2
計量
- 文章訪問數: 147
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- PDF下載量: 5
- 被引次數: 0
出版歷程
- 收稿日期: 2009-01-12
- 網絡出版日期: 2021-08-09

Thermodynamic analysis on phosphate decomposition of calcium molybdate

1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Changsha 410083, China;
3. Research and Development Center of Advanced Materials & Equipment Technology, Hunan Aerospace Administration Bureau, Changsha 410205, China

摘要

摘要: 針對磷酸鹽分解鉬酸鈣的過程,根據同時平衡原理和質量守恒定律,繪制了25℃時Ca-Mo-P-H₂O體系溶解組分的lg_C-pH圖,以及不同總磷濃度條件下溶液中總鈣、總鉬的lg_C-pH圖和鉬酸鈣穩定區.結果表明,在溶液中總磷濃度一定的條件下,隨著pH的增大體系中會依次出現H₂MoO₄(s)、CaMoO₄(s)、Ca₅(OH)(PO₄)₃(s)和Ca(OH)₂(s)穩定存在的區域.總磷濃度直接影響到鉬酸鈣的分解過程,隨著總磷濃度的增加,鉬酸鈣的穩定區域不斷減小甚至消失,使得鉬酸鈣更加易于分解,因此溶液中總鉬濃度不斷增大,而總鈣濃度不斷降低;但總磷濃度過高會導致溶液中殘留游離含磷離子過高.從熱力學角度來看,在鉬酸鈣分解過程中,添加磷酸鹽比碳酸鹽更加有利于鉬酸鈣的分解.
- 磷酸鹽 /
- 鉬酸鈣 /
- 熱力學 /
- 分解
Abstract: According to the laws of simultaneous equilibria and mass conservation, the logarithm concentration-pH diagram of a Ca-Mo-P-H₂O system, the logarithm eoncentration-pH diagrams of total calcium and total molybdenum at different total phosphate concentrations, and the stabile area of calcium molybdate at 25℃ were obtained on the basis of thermodynamic data. The results show that the stabile areas of H₂MoO₄(s), CaMoO₄(s), Ca₅(OH) (PO₄)₃(s) and Ca(OH)₂(s) are distinguished orderly with increasing pH values at a constant total phosphate concentration. Calcium molybdate can be easily decomposed since the stabile area of calcium molybdate shrinks or even disappears with increasing total phosphate concentration; at the same time, the total molybdenum concentration increases, and the total calcium concentration decreases. However, high phosphate concentration is unnecessary for calcium molybdate can be decomposed at a very low phosphate concentration. Compared to carbonate, phosphate is more propitious to the decomposition of calcium molybdate.
- phosphate /
- calcium molybdate /
- thermodynamics /
- decomposition