Editing Anthracite (section)

===High grade===
High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles).

High grade and ultra high grade anthracite are harder than standard grade anthracite, and have a higher relative density. An example of a chemical formula for high-grade anthracite would be C<sub>240</sub>H<sub>90</sub>O<sub>4</sub>NS,<ref>{{cite web|title=Coal characteristics: Indiana Center for Coal Technology Research Basic Facts File #8|url=http://www.purdue.edu/discoverypark/energy/assets/pdfs/cctr/outreach/Basics8-CoalCharacteristics-Oct08.pdf|publisher=Indiana Center for Coal Technology Research|access-date=15 May 2012}}</ref> representing 94% carbon.<ref>{{cite web|url=http://www.webqc.org/molecular-weight-of-C240H90O4NS.html|title=Molar mass of C240H90O4NS|website=www.webqc.org}}</ref> UHG anthracite typically has a minimum carbon content of 95%.

They also differ in usage from standard grade anthracite (used mainly for power generation), being employed mainly in metallurgy as a cost-efficient substitute for [[coke (fuel)|coke]] in processes such as [[sintering]] and [[Pelletizing|pelletising]], as well as [[Pulverized coal injection method|pulverised coal injection]] (PCI) and direct injection into [[blast furnace]]s. They can also be used in [[water purification]] and domestically as a [[smokeless fuel]].

HG and UHG anthracite account for a small percentage of the total anthracite market. The major producing countries are Russia, Ukraine, Vietnam, South Africa and the US.

{| class="wikitable" style="clear:left"
|+Standard classifications by size
!Name     !!Imperial (inches) !!Metric (mm)
|-
|Chestnut || {{convert|7/8|-|1+1/2|in|mm|disp=table|abbr=on}}
|-
|Pea      || {{convert|9/16|-|7/8|in|mm|disp=table}}
|-
|Buckwheat|| {{convert|3/8|-|9/16|in|mm|disp=table}}
|-
|Rice     || {{convert|3/16|-|3/8|in|mm|disp=table}}
|-
|Barley   || {{convert|3/32|-|3/16|in|mm|disp=table}}
|}

The primary sizes used in the United States for domestic heating are Chestnut, Pea, Buckwheat and Rice, with Chestnut and Rice being the most popular. Chestnut and Pea are used in hand fired furnaces while the smaller Rice and Buckwheat are used in automatic stoker furnaces. Rice is currently the most sought-after size due to the ease of use and popularity of that type of furnace.

In [[South Wales]], a less elaborate classification is adopted, but great care is exercised in hand-picking and cleaning the coal from particles of pyrites in the higher qualities known as best malting coals, which are used for kiln-drying malt.{{sfn|Bauerman|1911|p=106}}<!-- Likely obsolete information -->

Anthracite dust can be made into [[coal briquette|briquettes]] and is sold in the United Kingdom under trade names such as [[Phurnacite]], Ancit and Taybrite.