The invention relates to a preparation method of low temperature sulfur-free and heavy metal-free expandable graphite, which relates to the preparation method of expandable graphite. It is to solve the technical problems of heating, long reaction time and heavy metal impurities in the production process of sulfur-free expandable graphite. In this method, flake graphite and perchloric acid solution were mixed at temperatures of 25 ~30 C to obtain primary expansible graphite, and then alcohol was added to the flake graphite and stirred evenly to obtain expansible graphite. The preparation process does not produce waste water. The expandable graphite has a shelf life of more than one year at room temperature, is convenient for transportation and storage, and is conducive to expansion in different places. The expanded graphite is expanded at 420 - 1100 (?) C to obtain sulfur-free and heavy metal-free expanded graphite. The expansion process does not produce smoke and is environmentally friendly. The volume of expanded graphite can be controlled within 280ml/g-800ml/g, and the quality of the product is excellent. It can be used in the fields of petrochemical industry, aviation, machinery and nuclear industry.
【技术实现步骤摘要】
一种低温无硫、无重金属可膨胀石墨的制备方法
本专利技术涉及可膨胀石墨的制备方法。
技术介绍
膨胀石墨,也称柔性石墨,它是一种疏松的、似蠕虫的炭材料,在石油、化工、航空、机械、核工业有广泛的应用,并且其应用范围在不断扩大。膨胀石墨的原料是鳞片石墨,鳞片石墨具有石墨的层状晶体结构,层内的碳-碳(C-C)以sp2杂化相互结合、键角为120o形成六方结构,C-C间还有π-π键相连,形成超大层状结构,由于层内超大的离域π的存在,使其层内具有良好的导电性。同时,鳞片石墨中C-C间的σ键和离域大π键的共同作用结果,使其具有超高的稳定性。石墨层间以较弱分子间力相互结合,所以层间可以剥离或插层。因为层间的作用力较弱,在力的作用也可以使鳞片石墨膨化至数百倍至上千倍。现有的可膨胀石墨的制备方法有电化学法、化学氧化法等。申请号为200410027920.9的中国专利公开的一种可膨胀石墨的制备方法,该方法是将鳞片石墨放置在反应槽中平行的电极板之间,将石墨浸泡于由有机酸、浓硝酸、KMnO4和FeCl3配制而成的混合液中,在两电极之间加直流电流,进行反应,然后取出水洗,干燥,制得可膨胀石墨。再 ...
【技术保护点】
1.一种低温、无硫、无重金属可膨胀石墨的制备方法,其特征在于该方法按以下步骤进行:一、将鳞片石墨与质量百分浓度为50%~78%的高氯酸溶液在温度‑25℃~30℃的条件下混合搅拌均匀,得到初级可膨胀石墨;二、将多元醇或多元醇溶液加入到初级可膨胀石墨中,在温度‑25℃~30℃的条件下搅拌均匀,得到可膨胀石墨;其中多元醇为乙二醇或丙三醇,醇溶液是将质量百分数为10%~30%的水、甲醇或乙醇加入多元醇中配制而成的溶液。
【技术特征摘要】
1.一种低温、无硫、无重金属可膨胀石墨的制备方法,其特征在于该方法按以下步骤进行:一、将鳞片石墨与质量百分浓度为50%~78%的高氯酸溶液在温度-25℃~30℃的条件下混合搅拌均匀,得到初级可膨胀石墨;二、将多元醇或多元醇溶液加入到初级可膨胀石墨中,在温度-25℃~30℃的条件下搅拌均匀,得到可膨胀石墨;其中多元醇为乙二醇或丙三醇,醇溶液是将质量百分数为10%~30%的水、甲醇或乙醇加入多元醇中配制而成的溶液。2.根据权利要求1所述的一种低温无硫、无重金属可膨胀石墨的制备方法,其特征在于步骤一中所述的鳞片石墨的粒度为30目~100目。3.根据权利要求1或2所述的一种低温无硫、无重金属可膨胀石墨的制备方法,其特征在于步骤一中1g鳞片石...
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