Plomosas' ore will be processed through Grupo Mexico's Santa Eulalia concentrator as part of the deal, and concentrate will be sold and delivered to the company's San Luis Potosi smelter.

The company will run one to four lots of 2,500t per month beginning in September. It expects cashflow from its production will be seen in October.

Plomosas' mining will follow the schedule of Cube Consulting, and its mining contractor Servimin Sara has been mobilised to the Level 5 area, where it can immediately access Tres Amigos.

Over the first month Servimin Sara will mine 3,000 initial tonnes, then ramp up to 7,500t/m by the end of this year. October will be the first full month of delivery to the concentrator.

The Plomosas operation will use airleg stoping, and also possibly bord-and-pillar mining when and where feasible.

"The board's decision to commence mining, having secured toll treatment and concentrate offtake agreements is a low-risk, fast return option that will see mining re-established for a low capital cost," CEO Brad Marwood said, noting that additional exploration to boost reserves is ahead.

"Recent exploration success has been significant, and I anticipate that we will continue with more discoveries at Plomosas that will underpin CZL's future. The opportunities and several targets have been identified and can now be funded.

"We look forward to working with Grupo Mexico, which has an impressive record in Latin America, and hope to continue developing opportunities together."

Consolidated Zinc owns 51% of the Plomosas project.