By David Gambrel
International coal salesmen sometimes learn the hard way (quality penalties) the coal received by the foreign buyer is not the coal they intended to ship. Mysteriously, the coal became contaminated before it got to the customer. What happened, and will it happen again?
Raw coal is usually crushed and sized; it may include impurities found in situ, namely fire clay and various forms of slate and shale. Washed coal should be relatively free of impurities. The coal salesman should know the quality of the coal he is selling because his company’s laboratory should have tested many samples. Knowing the quality assumes, of course, that nothing has happened to the coal between the time it was tested and the time it was loaded into the ship. This can be a very naïve assumption.
How was the coal loaded into barges or rail cars? Did it go directly from a preparation plant into a coal silo and from the silo into a rail car or barge? If so, it doesn’t seem there would be much contamination. On the other hand, if the coal was stockpiled on muddy ground near a railroad track and loaded into rail cars with a front-end loader, there is a reasonable expectation it will become contaminated with mud. This would be un-intentional contamination. The mine operator might very well be saving the one-time cost of a concrete stockpile base, but getting repeated Btu penalties for contaminating his own coal.
What could possibly happen to rail coal on the way to the terminal? Occasionally railroad track crews have thrown old spikes and other waste into railroad cars and these are sometimes found clinging to the magnetic separators on the conveyor belts at terminals. One prominent rail-served terminal has reported finding such unusual items as a flattened 55-gallon drum, a set of deer antlers, and a dead man in silo-loaded trains. One could almost justify a flattened oil barrel and the deer could have been thrown in by anyone, but the dead man is a mystery.
Barge-originated exports are confined primarily to mines serving the Upper Ohio River and the Port of New Orleans, mines serving Southern Appalachia and the Port of Mobile, and to a lesser extent, western mines serving the Mississippi/ Ohio River Systems and the Port of New Orleans. Most of these mines will have an initial truck or rail haul to a barge terminal. In the context of ocean shipping, the Port of New Orleans extends from the Head of Passes to Baton Rouge, the final 200-mile stretch of the Lower Mississippi River. This stretch will accommodate vessels of Panamax and sometimes Capesize capacities.
One opportunity for unintentional contamination occurs right at the stockpile area of the barge loading terminal. In large modern terminals coal is dumped from rail cars or trucks into hoppers and conveyed out to a stockpile area via a system of conveyor belts. If the stockpile area has a compromised base (soil, waste coal, sea shells, etc.), one should expect to find some of these contaminants in the coal loaded into barges. Front-end loaders, bulldozers and other equipment used to push coal into the reclaim hoppers will inadvertently push in some of the base material, the amount being a function of how soft the base material has been made by precipitation, and how careful the equipment operator is. Some terminals avoid the addition of base contamination by having a concrete base.
Precipitation and leaky barges provide an opportunity to get rain or snow mixed in with the coal. Covered barges are used primarily for grain, but may also be ordered for coal shipments. They invariably cost more, but may be worth the additional cost to keep water out of the coal as it goes downriver. Modern terminals load barges so that coal almost fills the entire void, but crane-loading operations usually leave the coal in conical piles with parts of the barge bottom uncovered. The latter are much more likely to form water puddles around the base of the coal piles, a constituent of acid production and spontaneous combustion. Ship loading terminals on the Lower Mississippi River have reported barges arriving with small coal fires around the base of such poorly-loaded piles in barges.
Intentional Coal Contamination
Layer-loading is a serious and intentional method of selling inferior product to an unsuspecting broker. It can happen with railcars, trucks or barges, and it usually works like this. The broker may be shown a stockpile of clean coal and given a sheet of good “test results.” The broker signs a purchase agreement and goes back to his office, confident he has made a good deal. If the coal is to be hauled to the ship-loading terminal in railcars, the original coal seller has one main chance to do his dirty work. He loads the bottom of each rail car with coal waste, and puts good coal on top. He belie