Abstract
Process safety officials often place great emphasis on the results from tests to define various fire and explosion hazards inherent in dusts. These include the flammability, the autoignition temperature, the lower explosive limit, and sometimes the K~st~‐value which is a characteristic equivalent to the maximum pressure rise in a 1 m^3^ vessel of an optimally combined substance/air mixture when the temperature is 20°C and pressure was 100 kPa before the explosion. It is also important to know if there is any electrostatic hazard. Tests of the specific volumetric resistance, the minimum ignition energy, the electrostatic chargeability, the relative permittivity and the discharge time contribute to determining this specific hazard.
If the substance is also subjected to elevated thermal conditions, the safe process temperature should be tested by the help of thermoanalytical techniques [1, 2, 3, 4]. If the dust indicates the characteristics of an explosive in such tests, its sensitivity to impact should be tested, and if the substance is sensitive to impact, its sensitivity to friction should also be tested [5, 6, 7]. Note: many of the tests used for process safety studies in the chemical industry have been adapted from the explosives industry.
The significance of friction testing for expert decisions regarding grinding operations on non‐explosive chemicals when the test results of the sensitivity to impact were negative is introduced in this paper.