Excelsior remains on-schedule for first copper production in the December 2019 quarter.

The Gunnison copper project has six major ponds represented by five types: Pregnant leach solution (PLS), raffinate, evaporation, utility and draindown ponds. Some ponds are retrofits of existing ponds, while others are completely new constructions.

Stephen Twyerould, president and CEO of Excelsior Mining, said: "The successful installation of all the ponds signifies the completion of a major construction milestone. We are pleased with our progress to date and we look forward to unlocking the incredible economic benefits for local and state communities as we bring our project into production later this year."

Together, the PLS and raffinate ponds provide a closed-loop system for circulating mining fluids between the JCM production facilities and the wellfield. Excelsior recently completed the pipeline corridor that contains 18in (45.7cm) and 20in (50.8cm) diameter PLS and raffinate lines.

Excess solution will be transferred to the evaporation pond. Excelsior's federal operating permit requires a bleed in excess of recovered solutions in order to maintain hydraulic control of wellfield operations. This bleed will be delivered to the evaporation pond for mechanically assisted evaporation.

Additionally, there is a new utility pond that will be able to accept either raffinate or PLS solutions to give operational flexibility; and there is also a newly constructed pipeline draindown pond that will capture any solutions should we need to perform maintenance on the pipeline.