How to check flake graphite impurity?

Flake graphite contains certain impurities, then flake graphite carbon content and impurities are how to measure it, the analysis of trace impurities in flake graphite, usually the sample is pre-ash or wet digestion to remove carbon, ash dissolved with acid, and then determine the content of impurities in the solution. Today we will tell you how the impurity of flake graphite is determined:
The determination method of flake graphite impurities is the ashing method, which has some advantages and some difficulties.

1. the advantages of ash method.
Ashing method does not need to use pure acid to dissolve ash, so as to avoid the risk of introducing elements to be measured, so it is used more.

2. the difficulty of ash method.
It is also difficult to detect the ash content of flake graphite, because the enrichment of ash requires high temperature burning, and at high temperature the ash will stick to the sample boat and is difficult to separate, which leads to the inability to accurately determine the composition and content of impurities. The existing methods take advantage of the fact that the platinum crucible does not react with acid, and use the platinum crucible to burn the flake graphite to enrich ash, and then directly heat the sample with acid in the crucible to dissolve the sample, and then determine the components in the solution to calculate the impurity content in the flake graphite. However, this method has certain constraints, because the flake graphite contains a large amount of carbon, which can make the platinum crucible brittle and fragile at high temperature, easily causing the rupture of the platinum crucible. The detection cost is very high, and it is difficult to be widely used. Because the impurities of flake graphite can not be detected by the conventional method, it is necessary to improve the detection method.

Post time: Aug-06-2021