Mission Copper Mine Complex

Project Overview

The ASARCO Mission Mine Complex is located in East Central Pima County, approximately 18 miles southwest of Tucson, Arizona. The mine complex extends over an area of approximately 19,000 acres and includes the Mission integrated open pit, crushing, grinding, and flotation facilities; tailings facilities; waste rock dumps; and warehouse, maintenance, and administrative areas.

Project Role

Knight Piésold was retained by ASARCO-Mission to produce an assessment and alternatives evaluation for selection of a new tailings disposal area. Six tailings disposal options were developed and analyzed. A preferred option was selected by the client for further analysis in a pre-feasibility study (PFS). After completion of the PFS, Knight Piésold performed detailed design for an expansion of Tailings Storage Facility (TSF) No. 4 and has become the Engineer of Record for that facility.

Services provided by Knight Piésold include:

• Permit requirements review and analysis
• Development of a decision matrix and fatal flaw analysis
• Site-specific characteristics evaluation
• Analysis of social and environmental constraints
• Conceptual design development and cost estimates for each option
• Pre-feasibility study
• Detailed design of TSF No. 4 expansion
• Tailings deposition modeling using Muck 3D
• Geotechnical stability analyses
• Site investigations including CPT and piezometer installation
• Engineer of Record services including TSF inspections