Sulfur-retention Characteristics of Different Coal Mixtures

To study the sulfur-retention characteristics of different coal mixtures, experimental tests were carried out by blending Pingshuo mid-sulfur coal with 3 typical low-sulfur coals in different proportions. Results indicate that the efficiency of sulfur-retention has relations with the molar ratio of (Ca+Mg)/S in coal and the content of (CaO+MgO) in ash. When the mid-sulfur coal of low (Ca+Mg)/S ratio is blended with a low-sulfur coal of low (Ca+Mg)/S ratio, the utilization rate of (CaO+MgO) will decrease with rising (Ca+Mg)/S ratio in the coal mixture, in which case, the sulfur removal effect mainly comes from the dilution of sulfur by the blending coal; whereas when the mid-sulfur coal of low (Ca+Mg)/S ratio is blended with a low-sulfur coal of high (Ca+Mg)/S ratio, the utilization rate of (CaO+MgO) will reach the highest at a (Ca+Mg)/S molar ratio of 0.8-1, in which case, the sulfur removal effect comes from both the sulfur dilution and sulfur retention by the blending coal.