Are coal logs wear-resistant in pipe?
Some are and some are not, depending on how you made them, and what kind of coal is used. The worst coal logs we made break up readily upon leaving the compaction mold; they are unsuitable for transport by pipeline. On the other hand, very strong logs can be and have been made. During the field test in Conway, Kansas, the worst logs broke up in the pipe but did not clog the flow, and the best logs lost only about 0.5% of weight during a 5-mile run through the pipe. In the laboratory, the strongest small logs (1.91-inch diameter) were circulated through a 2-inch-diameter pipe loop for a distance of 200 miles with 5% weight loss. Generally, the strongest logs are made from subbituminous coal mined at the Powder River Basin, Wyoming. The weakest coal logs made (i.e., the most difficult to compact) are compacted from anthracite coal.
