利用细鳞片石墨制备膨胀石墨的研究

THE PREPARATION OF EXPANDED GRAPHITE USING FINE FLAKY GRAPHITE

采用化学方法制备了细鳞片膨胀石墨 ,并对其最佳工艺条件进行了探讨。结果表明 :将 10 0目～ 16 0目的细鳞片石墨置于硫酸∶硝酸 =5 .0～ 7.5∶1.0的主酸化液中酸化 ,并分步加入 6W/%～ 7W/%的强氧化剂(KMnO4) ,6W/%的插入剂 (FeCl3 )继续搅拌 2h以上 ,经水洗至pH =5～ 7,烘干后在 90 0℃～ 10 0 0℃的高温下膨胀 ,可制得膨胀倍数为 180倍～ 2 0 0倍 ,松装密度在 0 .0 12 5g/mL ,灰分为 2 .0 6 3W/%～ 2 .4 70W/% ,硫分为 0 .2 13W/%～ 0 .2 33W/% ,挥发分为 4 .5W/%～ 8.5W/%的优质膨胀石墨。与已有的方法相比 ,所使用硝酸的比例降低了 30%～ 6 0 % ,且一次性完成酸化处理 。

The preparation of expanded graphite from a fine flake graphite using a chemical method was studied to determine the optimum conditions. The results show that high-quality expanded graphite with an expansion ratio of 180 similar to 200, a bulk density 0.0125 g/mL, ash content 2.063 W/% similar to 2.470 W/%, sulphur content 0.213 W/% similar to 0.233 W/% and volatilization 4.5 W/% similar to 8.5 W/% can be attained by the following procedure. First, acidify 100 160 mesh fine flaky graphite in a mixture of sulphuric acid and nitric acid (5.0 similar to 7.5:1.0); then add 6 W/% similar to 7 W/% strong oxidant (KMnO4) and 6 W/% FeCl3, stirring it for over 2 h. Finally after washing in water to a pH 5 similar to 7 and drying, expand it in the temperature range 900 degreesC similar to 1000 degreesC. The method is simple and has advantages over present methods in that nitric acid used in the processing was reduced by 30 to 60 % and only one acidifying treatment was required.