Determination of Coarse Particles of Acetylene Black
Acetylene black, also known as channel black, is a black, non-graphitic, highly conductive and heat-resistant substance used for conductive coatings, propellants, carbon brushes, and other applications. The natural acetylene black consists of particles in size from 0.04 to several millimeters, with an extremely variable shape. Its compactness allows it to be easily compacted and used as an electrically electrically and thermally conductive electrode material. Acetylene black is an important raw material in some industries and the quality of the material is strictly controlled. Therefore, the determination of its particle size is essential for quality control.
This paper is about the determination of the coarse particles of acetylene black through a method defined in China’s GB/T3781.5-93 standard. This method applies to the determination of coarse particles in acetylene black with a particle size of 0.4 mm-4.0 mm.
According to the instructions, the sample needs to be placed and spread evenly on the screen at the top of the sieve mesh. Be sure to leave enough space between the sample and the wall, and shake the sieve until the sample passes through and is evenly distributed on the mesh. When the time is up (15 minutes as stated in the regulations), the sample which is retained on the sieve should be transferred to an appropriate container and then onto a flat bottom container with a dry cloth.
Weighing comes next. The sieve containing the sample should be weighed accurately using an electronic balance. The time of weighing should not be too long, otherwise the sample may settle, leading to inaccuracy. After that, the mesh will be shaken gently to make the sample stand on the mesh evenly and then weighted again.
The data obtained from the weighing process will be applied to a sieve-construction diagram. Sieving by weight is used to calculate the weight of each fraction. According to the above regulations, the respective value of weight-percentage of each fraction should be calculated and taken as the coarse particles size of the material.
It is important to note that standards may differ in each situation, and that different instruments may be required to determine the coarse-particles size of a particular material. Therefore, it may be necessary to consult with an experienced technician to further interpret the results in order to ensure that the sample is of the required specification.
To conclude, the method presented here is a useful guide to determining the coarse-particle size of acetylene black, however, more technical knowledge is likely needed when using this method in a practical setting. Operators should also be aware of the safety precautions applicable when using this type of materials as they may contain hazardous substances.
