Coal Mining Market Size, Share & Industry Analysis, By Mining Method (Surface Mining and Underground Mining) By Grade (Low-Grade Coal (Lignite), Medium-Grade Coal (Sub-bituminous), High-Grade Coal (Bituminous), and Ultra-High-Grade Coal (Anthracite)), By End User (Power Generation, Steel Manufacturing, Cement Production, Chemical & Synthetic Fuels, Paper & Pulp, and Others) and Regional Forecast, 2026-2034