Coal breaker

[4][5][6] At least one source claims that, in 1873, coal breaking plants were found only at anthracite mines in Pennsylvania.

[2][8] Chunks of coal which were too large were then crushed (sometimes several times) in the tipple until it passed through the screen (e.g., was of acceptable steam size or smaller).

Raw coal often contains impurities such as slate, sulphur, ash (or "bone"), clay, or soil, which requires that it be cleaned before shipment to market.

[2][8] Slate, sulphur, and ash have a higher relative density than coal, and will sink in agitated water.

[9] The coal fell into a second screen, where it was shaken (by hand, animal, steam, or water power) and the smaller lumps sorted.

[10] Shortly after the start of the 19th century, experiments in the United States showed that if anthracite coal lumps were more uniform in size and air flowed more evenly around the fuel, anthracite would burn hotter, more cleanly, and for a longer period of time than bituminous coal.

His method and 'discovery' in Wilkes-Barre, PA in 1808 led to the widespread use of coal as the fuel source that helped to foster America's industrial revolution.

[11][13] Efforts were soon made to discover ways to process anthracite coal to achieve the desired uniformity.

[4] Larger chunks of coal, falling inside the cylinder as it rotated, broke up and eventually passed through the screen.

[9] A fellow Pennsylvanian, Gideon Bast, licensed the technology from Battin, and erected the first commercial coal breaker in Schuylkill County, Pennsylvania, on February 28, 1844.

[4][9] A number of coal processing machines—such as rollers, crushers, washers, and screens—were developed in Europe and later utilized in the United States.

[1] By 1866, the coal breaker in the United States had taken the form most recognized today, with multiple stories and numerous screening processes and mechanical sorting devices.

[3][19] The breaker boys would sit on wooden seats, perched over chutes and conveyor belts, picking slate and other impurities out of the coal.

[9][15][16][21] The "dry" coal kicked up so much dust that the breaker boys sometimes wore lamps on their heads to see, and asthma and black lung disease were common.

[19][20] But the law was poorly enforced, and many employers and families forged birth certificates or other documents so children could work.

[16][25] The practice of employing children in coal breakers largely ended by 1920 because of the efforts of the National Child Labor Committee, sociologist and photographer Lewis Hine, and the National Consumers League, who educated the public about the practice and succeeded in passing child labor laws.

In the United Kingdom, the government enacted a law in the mid-19th century requiring that coal breakers be built away from mine entrances.

But in 1871, a fire destroyed the wooden breaker built over a mine opening in West Pittston, Pennsylvania, trapping and killing 24 miners.

[1] In these wet separators, a very dense medium (such as magnetite) is introduced into an agitated mixture of coal and water.

[34] The dense media drops to the bottom of the tank, sending water and the lighter material (such as coal) over the top for collection and drying.

[35] Automation led to very significant reductions in the number of people needed to run plants, with smaller modular facilities sometimes requiring only a single operator.

[3][4] In the typical coal breaking plant at the beginning of the 20th century, the coal entered the plant at the upper floor and slid down a gently inclined "picker table" where breaker boys removed obvious impurities such as rocks and large pieces of slate and threw them down chutes to the culm pile.

Here, a series of interlocking, toothed crushers or rollers would break lump coal into progressively smaller sizes.

[2] At this level, the use of conveyor belts (with or without paddles or scoops) was necessarily in order to move the smaller grades of coal, with most belts moving at about 33 feet per minute for pea coal and 50 feet per minute for larger grades.

Dry culm was taken away from the coal breaker by conveyor belt or rail car and dumped nearby.