论文部分内容阅读
铝酸钠溶液的分解反应是拜耳法生产氧化铝的重要基础。研究分解反应,必须研究分解速度与分解产物的质量。本文仅就反应温度及溶液组分对分解速度的影响加以闡述。根据基础試验和中間試驗的結果并参考了文献中的試驗示例,对影响分解速度的問題做了研究,得出如下結論。1.分解初期,于高温下分解速度最快,分解后期轉变为于低温下分解速度較快。2.降温温度斜率愈大,分解速度愈快。此种現象尤以高温时最显著。3.在某一碱濃度下,有一最大析出速度。这是因为愈接近析出末期,濃度亦愈大的缘故。4.分解初期克分子比愈大,分解速度亦愈快,但經过一段分解过程后,由于溶液中殘存的Al_2O_3阵低,分解速度反而变慢。
The decomposition reaction of sodium aluminate solution is an important basis for the production of alumina by Bayer process. To study the decomposition reaction, the speed of decomposition and the quality of decomposition products must be studied. This article only on the reaction temperature and solution components on the decomposition rate are described. Based on the results of the basic and intermediate tests and with reference to the experimental examples in the literature, the problems affecting the rate of decomposition are studied and the following conclusions are drawn. 1 early decomposition, the decomposition of the fastest speed at high temperatures, decomposed into late at low temperatures decomposition faster. 2. cooling temperature, the greater the slope, the faster decomposition. This phenomenon is especially noticeable at high temperatures. 3. At a certain alkali concentration, there is a maximum rate of precipitation. This is because the closer to the end of precipitation, the greater the concentration of the reason. 4. The larger the molar ratio of decomposition, the faster the decomposition rate, but after a period of decomposition process, due to the low Al 2 O 3 array in the solution, the decomposition rate is slower.