大理岩型石墨矿中固定碳的测定方法

用稀王水溶解样品，过滤，洗涤，以消除碳酸盐，硫化物，可溶性铁，浮炭，有机物和化合水对测定固定碳的干扰。在６００℃灰化滤纸并线化固定碳９０ｍｉｎ称重，然后在１０００℃灼烧至恒重，前后两次重量之差值为固定碳的结果。与原用８５０℃灼烧重量法相比较，该法避免了固定碳在第一次灼烧中被氧化损失，分析结果的准确度与吸收重量法和气体体积法相符。

A Method for Determination of Fixed Carbon in Marble Graphite Ores

A method for the determination of fixed carbon in marble graphite ores was reported in this paper. The sample was decomposed by dilute aqua regia. The solution was filtered and the precipitant was washed to remove the interferences from carbonates, sulfides, soluble iron ions, floating carbon, organisms and chemically combined water on the determination of fixed carbon. The precipitant with filter paper was ashed in a furnace at 600 for 90 mins and weighted after cooling, then ignited at 1000 to constant weight. The fixed carbon content in the sample can be calculated from the difference between two weightings. The method exhibits more reliable over the original gravimetric method with 850 ignition temperature, due to the avoiding oxidizing loss of the fixed carbon in original method. The results are in agreement with those provided by absorptiongravimetry and gas volumetry with precision of 2.0% RSD (n=12).\=\=