Tyrone Mine Facility Permit Renewal


Freeport-McMoRan Copper & Gold Inc.


Tyrone, NM

CEC Services

  • Air Dispersion Modeling
  • Air Quality Permitting

Owner Objective

Freeport-McMoRan Copper & Gold Inc. needed to obtain an operating permit for the Tyrone Mine that would allow for facility operation, expansion, and reclamation activities to proceed over the five-year life of a new permit with limited or no permit revisions. The Tyrone Mine is an open-pit copper mining complex, located approximately 10 miles south of Silver City, New Mexico. The Tyrone Mine is a porphyry copper deposit. Mineralization is predominantly secondary sulfide consisting of chalcocite with leachable oxide mineralization consisting of chrysocola. Tyrone’s copper processing facilities consist of a solution extraction/electrowinning (SX/EW) operation and ancillary operations.

CEC Approach

CEC provided air dispersion modeling services and assistance with the preparation of a Title V / New Source Review permit application. CEC’s activities included an initial review of data and information, as well as regulatory requirements pertinent to the portions of the permit application.

CEC developed an air dispersion modeling protocol relative to use of the USEPA AERMOD model, calculated the emissions, and compiled modeling input data. Following several meetings with the regulatory agency and subsequent revisions of the modeling protocols and application plans, CEC conducted air modeling with multiple iterations for maximized mine throughput taking into consideration a buffer zone within the site boundaries.

Based upon modeling results and the need for operations and reclamation planners (including optimization of haul road designs), CEC was able to meet Freeport-McMoRan goals without exceeding ambient air quality standards and a complete permit application, including dispersion modeling report, was submitted for Agency approval.