I'm not a coal miner, but I do have problematic skin. I think general skincare would be the most important starting place. Making sure you are using the most gentle soaps that will do the job, and never failing to moisturise after doing so. What does your skin care routine look like right now?
An alum block does wonders for my face after a shave. It's shave with red hot water > rinse with cold water > alum block, leave for 20 seconds > rinse with cold water > lotion. Takes away any razor burn, etc. I couldn't shave regularly without it. This is unrelated to working in a coal mine, though.
You're going to have to find products that work for you personally. My routine is pretty similar. I use Cerave facial cleanser and Cerave facial moisturiser. My electrologist is always gushing over the skin on my face, so I can't be doing that bad.
I don't have a whole lot of advice for coal mining itself, other than trying to keep a barrier between you and the filth. Less filth means losing less oil to washing, which will likely be your real problem.