Bitumen

Before feeding, sample has been embrittled in liquid nitrogen.

For grinding the total amount of sample, about 3 minutes will be required.

A grinding of higher amounts is still possible.

Pre ground sample of result 1 has been used for this test. Previously, sample has been embrittled in liquid nitrogen again.

After only 15g of sample which have been fed, grinding sound indicates that bitumen started to melt between the disks.

Grinding has been aborted after totally 60 seconds.

Sample has been pre ground analogue result 1. Afterwards, sample of < 1cm has been fed into the grinding bowl and liquid nitrogen has been filled into the bowl to chill the sample.

It is important waiting until all liquid nitrogen has been evaporated before the bowl will be closed (overpressure will cause a leakage – sealing will become pressed out).

After evaporation of nitrogen, sample has been ground for only 2 minutes. Because sample becomes hot rapidly, it is also possible interrupting the grinding process each minute and chilling the sample again with liquid nitrogen.

After 2 minutes of grinding, about 95% of particles use to be < 315µm.