The study looked at the sulfur content in coal from Hongyang Third Mine in Shenyang. They found that most of the sulfur in the coal is mineral sulfur, which is evenly spread throughout the samples. This sulfur is not affected by the size of the coal particles, their density, or the amount of ash present. Pyritic sulfur, found in small grains of coal, is hard to remove using common methods. Organic sulfur makes up 20% of the total sulfur in the coal.