“Coal” is often described as though it is one simple material. Today, the term is most frequently associated with the type of material that is used as a fuel in power generation. That concept brings to many minds the ideas of dirty, messy, polluting processes that contribute mightily to the debate on global warming and other air quality issues.
The fact is that the word “coal” is used to define a broad spectrum of carbon-rich materials that are present in the earth as a result of the deposit and decay of carbonaceous materials over long periods of geologic and atmospheric changes. Everything from peat to meta-anthracite is broadly defined as “coal,” and spoken of as though all of the spectrum had the same properties and uses.
There are many ways that anthracite is different from the coal that is the topic of most discussions in our world today. Here are a few of those differences:
- Anthracite is relatively rare, representing only about 1 percent of the world’s coal resources. It is similarly true for the U.S.
- Even anthracite is not a monolith in terms of quality. Some large deposits in the Far East, primarily China and some of the Eastern European material is semi-anthracite, a lower quality mineral with less carbon, higher ash and volatile content and often significantly higher sulfur content. The anthracite mined in Pennsylvania is of the highest rank and overall quality of any found in the world.
- Carbon is the key ingredient in all forms of coal. Anthracite has a higher carbon content than any other grade. Typical anthracite contains 85 percent or more carbon.
- Anthracite contains less volatile material than other forms of coal. This lower volatile content promotes the clean, smokeless burning qualities of anthracite. This lower volatile content also minimizes the potential for “auto-ignition” of anthracite, as is at times an issue with bituminous piles.
- When compared to other forms of coal, anthracite has very low ash content, resulting in a more complete combustion in fuel uses.
- Anthracite is typically low-sulfur, allowing a more flexible application set.
- Anthracite is not used as power plant fuel in the developed world. Primary uses are space heating for homes and commercial applications, steelmaking in electric arc furnaces, municipal water filtration, contamination cleanup applications, and as a reducing agent and heat source in kilns. These applications take full advantage of anthracite’s prime characteristics.
- When used in steelmaking, anthracite is ready-to-use and, unlike metallurgical coal, does not require “coking.” This results in anthracite having a more favorable carbon footprint than coke when used in this application.
- In the United States, all anthracite mining is performed in areas that were previously mined both underground and from the surface. Continued mining promotes the completion of the job ‒ removing the coal and reclaiming the surface for future use, and restoring the water quality in the region’s streams.
- Anthracite has a unique chemical and pore structure that could promote emerging uses in specialty carbon applications, many of them non-fuel uses.
We have a slogan that goes like this:
“It’s not just coal, it’s Anthracite.”
This is NOT like other forms of coal. It is harder, hotter, clean burning and highly useful in filtration and, has an interesting chemical and surface structure that we believe will make it an attractive resource in other emerging applications.
Posted on 01/11/18
By Greg Driscoll