The same coal, I mean – if it’s good enough to make coke for a blast furnace (or whatever has replaced blast furnaces) is it too expensive for power plants?
How about decades ago? Did most met coal come from mines that just fed blast furnaces?
The Navaho Generation Plant at Page AZ is fed directly from a mine.
The mine had no other customers. I may be missing your point.
Generally, metallurgical coal and thermal coal are different in composition and not mined together, but there are some (usually multi-seam ones or complex mines) that do supply both - Grootegeluk mine in South Africa (been there), Curragh mine in Oz. I’m sure there’s others.
But it won’t be the same coal sold to both because yes, metallurgical coal is too valuable to just burn.
There are basically two types of coal in North America, eastern coal and western coal. Eastern coal is higher in sulfur content. Otherwise, coal is coal.
Both can be used in power plants or blast furnaces. The important thing for a steel mill is that it needs to have its own coke plant. Otherwise, the steel mill won’t be able to compete economically and will go out of business (as happened to Bethlehem Steel or whoever they became when they changed names a few times before they completely shuttered the Sparrows Point steel mill in Baltimore). Paying someone else to turn the coal into coke doesn’t work economically in the long term.
Power plants just burn coal, so they don’t need to turn it into coke first. But for power plants there is a huge cost difference in eastern coal vs. western coal due to economics and EPA regulations. Power plants on the eastern side of the U.S. have to play this balancing act with cheaper local eastern coal that costs more on the scrubber side after its burned (so that it meets EPA regulations) or more expensive western coal (since they have to pay more to ship it all the way across the U.S.) that doesn’t need as much scrubbing. The bean counters get paid big bucks to figure out exactly how much of each type of coal to use to minimize their costs and maximize profits.
Way back when, I worked in the largest coal fired plant in Ohio Edison (the plant is now closed). We had two piles of coal, eastern coal and western coal. Once the money folks figured out how much of each we were supposed to use, guys on bobcats shoveled the appropriate amounts from each pile into the hoppers.
I have done a lot of work in steel mills but not in the coke plant side of things. I assume that the coke plant has the same issues. It’s cheaper to buy local coal since it doesn’t have to be shipped as far but more expensive to burn it due to EPA regulations and sulfur content. I believe most coke plants prefer low sulfur coal, which is what I think @MrDibble is referring to with the term “metallurgical coal” but then again I could be wrong. Like I said, I didn’t work in that part of the mill.
Back in the old days, everyone just bought local coal. No one gave two hoots about sulfur content. Except of course for folks who lived in northeast U.S. since the acid rain from the high sulfur content would destroy the paint on their cars after a few years. And of course all of the other issues that acid rain caused to homes and the environment.
That is very much not the case. Sulphur is only one area of concern, there’s also ash content, other volatiles, just overall %C. All coal is not interchangeable, especially for coking.
Thanks for the info. Like I said, I didn’t work on that side of the mill and nobody ever told me there was a difference.
Anthracite?
Dan
Where was the plant? Avon? Lorain? Cleveland? That’s the ones I remember.
The Sammis plant in Stratton, OH.
This thread is a primary example of why we should not tolerate transphobia on the board, even a little. Because
@Una_Persson was a genuine expert in the field, and transphobes drove her off.
Similarly in NSW Australia Centennial Coal’s Springvale mine exclusively feeds the Mount Piper Power Station at Lithgow.
Victoria’s La Trobe Valley power stations eg Loy Yang A & B and Yallourn are exclusively fed from adjoining brown coal mines. Victoria has the world’s second-largest brown coal reserves
Anthracite coal (86%–97% carbon) has the highest heating value and burns the cleanest. It’s shiny and metallic. It comes from northeastern Pennsylvania, and was historically used for building heating and cooking to reduce air pollution in cities, and to limit the amount of storage space and ashes. Some railroads used it for their steam locomotives too, especially on passenger trains. Today it’s only really used in the metal industry, and I think for things like charcoal filters and such. It represents just 1% of US coal production today.
Bituminous coal (45%–86% carbon) accounts for nearly half of total U.S. coal production. It’s what you picture coal looking like, black with maybe a little sheen. It’s used to generate electricity and for making coke. West Virginia, Illinois, Pennsylvania, Kentucky, and Indiana produce most of it.
Subbituminous coal (35%–45% carbon) is the other half of total U.S. coal production, nearly all of which comes from Wyoming. It looks more like a charcoal briquette or lava rock, black and dull. Even though it has worse energy content than Bituminous coal, its low sulfur content means additional scrubbing of sulfur dioxide isn’t needed.
Lignite (25%–35% carbon) has the lowest energy content of all coal types. It’s brown, crumbly, and has high moisture content. It’s barely better than burning the dirt or peat that coal came from. North Dakota and Texas produce the most, but it’s only single-digit percentages of the U.S. total.
So the most likely candidate for delivering the same coal to both a coking/steel plant and a power plant would be bituminous.