1x Lignite Coal (the "ingot", not the powder) can be crafted into 1x Lignite Coal Block. However, 1x Lignite Coal Block can be crafted into 9x Lignite Coal.
I think the intent was to have a "storage block" for large amounts of lignite coal. Unfortunately, this crafting loop allows for acquiring an arbitrarily large amount of lignite coal after you acquire the first one just by spending some time crafting on a 3x3 grid.
It's not a big deal, as fuel isn't exactly hard to come by, but I thought it should be reported anyway.
stephen-smith
commented
2 years ago 
Pack Version 1.15
1x Lignite Coal (the "ingot", not the powder) can be crafted into 1x Lignite Coal Block. However, 1x Lignite Coal Block can be crafted into 9x Lignite Coal.
I think the intent was to have a "storage block" for large amounts of lignite coal. Unfortunately, this crafting loop allows for acquiring an arbitrarily large amount of lignite coal after you acquire the first one just by spending some time crafting on a 3x3 grid.
It's not a big deal, as fuel isn't exactly hard to come by, but I thought it should be reported anyway.