What are the benefits of higher quality anthracite?
Since anthracite occurs in the form of laminates in rock formations, its specific gravity, solubility, and hardness are variable and in relation to the impurities found with it. Research has shown that these impurities contribute to friability along the cleavage planes. Experience has shown that coal having the properties listed below is more resistant to size reduction because its density and hardness comes from the number of carbon to carbon bonds, rather than from its inherent rock. 1. Specific gravity 1.6-1.7 2. Acid solubility<2.0% 3.Moh's hardness>3.0 4.Volatile content<7.0% (dry basis) 5.Carbon content>80%(dry basis) Intermixing of sand and coal is also more readily controlled if the anthracite is of a high quality. High quality anthracite is more uniform in specific gravity because there is less rock. Particle size degradation is less prevalent because sand abrasion acts upon a smaller percentage of coal particles, and these particles are more durable because they have less coa
