This is the 11114th most frequent Russian word.
горнодобывающей
"Mining" or "related to mining industry."
The word "горнодобывающей" is used here as an adjective describing "промышленности" (industry), referring to activities involved in mining.
Горнодобывающей промышленности требуется современное оборудование.
The mining industry requires modern equipment.
The word "горнодобывающей" is used here to describe "инфраструктуры" (infrastructure), indicating the sector related to mining.
Компания занимается развитием горнодобывающей инфраструктуры.
The company is involved in developing mining infrastructure.
Here, "горнодобывающей" modifies "техники" (equipment), signifying that the equipment is used for mining activities.