2019-12-30_REVISION - M2019054 (44)

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Exhibit J Skull Creek Sand Project Mining Methods Earthmoving Equipment Fleet Mining at the Skull Creek Project will be accomplished using open pit methods and heavy earthmoving equipment. The equipment will consist of large tracked excavators, an in-pit pick breaker, large off-the-road haul trucks, bulldozers, and various support equipment. An approximate list of required equipment is provided below in table D-1. Table D-1. Earthmoving & Support Equipment Excavation Equipment Komatsu 1250 Excavator In-pit Pick Breaker+ Genset Haulage Equipment Komatsu HD 605 Haul Trucks Support Equipment Cat D9 Dozer Cat 988 Loader Cat 980 Loader Cat 140M Grader F750 Water Truck (3,000 gal) This equipment has been sized and selected to provide yearly production of approximately 1.0 Million tons of sand product from the processing facility. Open Pit Mining Maps D-1 and D-2 illustrate the size and extent of the open pits. Each pit is approximately 500 feet long and 100 feet wide at the pit bottom, with final depths around 200 feet. The pit walls will follow the Dakota-Cedar Mountain contact on the north at around 50 degrees and follow an overall pit angle of 45 degrees on the south. These dimensions will allow for ingress-egress of the pit equipment at the final depth as well as direct loading of the over-the-road semi- trucks for shipment to the processing facility. At times the overburden or sandstone may require ripping or preparation by the dozer to facilitate loading by the excavator. The large excavator will mine both sandstone and overburden, with Dakota Sandstone being placed in the in-pit pick breaker hopper for sizing and overburden loaded onto pit trucks or pushed by dozer to backfill. Product from the open pits will either be directly hauled from the pit to the processing facility or hauled by the mine fleet to the Product Stockpile (shown on Map D-3) for storage. Overburden spoil from the pits will either be placed in the Spoil & Product Rejects Stockpile (SPRS) or directly into the pit backfill as described below. Product rejects from the processing facility will be return-hauled to the Skull Creek Project and placed in either the SPRS or directly into pit backfill. 7 12/23/19