[count-your-change]

Stories from early settlers told of burning rocks and like any material in a fire the oil would cook out and support combustion. But as with using a retort to remove the oil burning the oil shale leaves behind the rock as an “ash” that has to be disposed of in some manner. Other countries may not have the problem of deciding what to do with it as the U.S. does. Since new coal fired plants face opposition because they “aren't clean enough”, a shale fired plant isn't likely to be accepted. Note the “low grade”.
The in situ removal of the oil would be/is possible if,IF restrictions are lifted. A natural resource that should be in use already for oil and leave the coal for electrical generation.

[edzo4]

Fly ash from coal is added to concrete to make it stronger and water resistant.

http://www.ecosmartconcrete.com/facts_what.cfm

Fly Ash

One of the most commonly used pozzolans in concrete is fly ash, a by-product from coal-fired power plants. Using fly ash in concrete generally decreases permeability, improves sulphate resistance and other durability aspects of concrete, and allows lower water content in the mixture. Using fly ash improves the plasticity and workability of fresh concrete, and produces a warmer colored concrete. The annual production of fly ash in the US and Canada is 60 million tonnes per year, and there will be an estimated 600 million tonnes produced worldwide by the end of this year. Currently, about 80 % of the fly ash produced ends up in landfills. In North America, fly ash is typically used to replace an average of 8 % of the cement in concrete, while in many European countries, the replacement rate is greater than 25%.