The reduction of “float” coal/rock dust contaminated with quartz along with toxic and radioactive metals must be minimized at its source, that is, at the rock/coal crushing cone directly under the bit-tip. Biochemical reduction and compaction concentrate the upper floodplain river mud-water load of toxic and radioactive metals into a thin coal layer adjacent to the seam boundary rock during the deltaic deposition period. Bit-tip distance to the rock boundary layer must be automatically controlled in real-time when mining in an undulating coal bed. The bit-tip force vector induces radiating fractures in the complex cleat-coal matrix. The next bit-tip strike must be in the radiated fracture zone of the first strike to minimize coal/rock crushing and “float” coal/rock dust generation. Horizon sensing on rotating cutting drums with bit-tip force vector data acquisition enables real-time signal processing algorithms to determine the drum-lacing pattern, bit-block orientation for minimum cutting energy, and “float” coal/rock dust generation