The image I have of coal processing in the late 1800's and early 1900's is simple - a few young miners standing on both sides of a picking table sorting the "wheat from the chaff" if you will. It's either good or bad, right? Following is a photo dating back to 1902 showing a picking table at Franklin.
Photo courtesy Washington State Historical Society, 1943.42.1056, Asahel Curtis photographer, circa 1902
Well, it wasn't quite so simple. Each mine and coal seam was different and a lot more complex. To illustrate, following are profiles of several mines in Pierce County contained in a 1914 report titled The Coal Fields of Pierce County prepared by Joseph Daniels and the State of Washington.
There was a whole lot of material in the mix and not a simple matter of mining just the good stuff and leaving all the bad stuff. Some seams like the following one at Carbonado contained less shale, sandstone and other contaminants and a greater percentage "coal", but it was still incumbent on men in the mines to load cars with highest percent cleanest coal possible. Despite miners best efforts, unusable material was inevitably included in what they hauled out of the mine.
According to the report, refuse in eastern mines could be as low as just 6 percent. In Washington, the figures were from 15 to 20% refuse with some mines operating at even higher levels waste. This placed even greater importance on sorting and washing operations. As we can see, the size of processing facilities could be quite large and complex.
Fairfax was a coke plant requiring more processing but the size of above ground operations was quite large for the size of the mine.
The picking table was a small part of the process and washing facilities design could be quite complex and vary significantly from mine to mine. Following is the flow chart for American Coal Company's facility at Spiketon.
In contrast, following is the washing plant process design at Carbon Hill Coal Company in Carbonado.
Note the difference in processing depending on jig.
No wonder the Carbonado plant was so large for being precariously perched along the Carbon River.
Photo courtesy Washington State Historical Society, 2011.0.158, circa 1898
Nothing simple or easy here.