- 期刊
臺灣鋯砂以苛性鈉熔融法試製二氧化鋯
Preparation of Zirconium Dioxide by Fusing Zircon with Caustic Soda
摘要
本試驗係利用臺灣產之鋯砂(Zircon)與苛性鈉熔融^(4, 10, 13, 15, 20, 24, 25)，先製成鋯酸鈉(Sodium zirconate)與矽酸鈉(Sodium silicate)，次將此混合固體置于水中，溶去大部份矽酸鈉及未反應的苛性鈉，再將鋯酸納濾出，鋯酸鈉經烘乾後，與鹽酸共熱製成氧氯化鋯(Zirconium oxychloride)^(5, 13, 14, 19, 25)，繼續加熱趕去多餘之鹽酸並將二氧化矽固化。鹽酸蒸乾後，加水將氧氯化鋯溶解並過濾之，除去二氧化矽及未反應之鋯砂，濾液加硫酸或硫酸納及亞硫酸或亞硫酸氫鈉後，加大量熱水，氧氯化鋯則水解成鹽基性硫酸鋯(Zirconium basic sulfate)沈澱，經過濾，洗滌，烘乾後，焙燒得二氧化鋯(Zirconium dioxide)，純度可達98%以上。
關鍵字
無資料並列摘要
Zircon was fused with caustic soda in a nickel crucible in a muffle furnace. The fused products contained, besides some unreacted zircon and caustic soda, a mixture of sodium silicate and sodium zirconate. The mixture was leached out severely so as to remove the sodium silicate and the unreacted caustic soda. Sodium zirconate was recovered as a residue. On drying the sodium zirconate and heating it with hydrochloric acid, zirconium oxychloride was thus obtained. Heating was continued so as to expel the excess hydrochloric acid and to solidify the silicon dioxide. After all the hydrochloric acid had been expelled, water was added to the residue to dissolve the zirconium oxy chloride. The solution was filtered to remove any silicon dioxide or unreacted zircon which might be remaining in it. To the filtrate, sulfuric acid(or sodium sulfate and sulfurous acid or sodium hydrosulfate) was added. By adding large amount of hot water to the filtrate, the zirconium oxyehloride was hydrolyzed into zirconium basic sulfate and separated out as a precipitate. It was filtrate out, washed and calcined. Zirconium dioxide of about 98% purity could be obtained by such method. The experiment showed that natural occurred zircon could be fused directly with caustic soda without any disadvantage. Preferably, the amount of caustic soda should be 1.5 times that of the zircon; the temperature should be above 700°C; fusion for 40 minutes was found to be adequate.