Silver Mining in the Mexican Heartland

The mines around Fresnillo are type localities for epithermal silver deposits. Due to the narrow type of mineralization, multiple development drives need to be installed to enable enough ore output to feed the mill on surface.

Requirements

Rapid early strength development
High final strength
Dense matrix to counter acid mine drainage
A minimum dosage of accelerator
Excellent yielding properties pf the shotcrete liner
Extended open time to allow long haulage distance of concrete to the point of use
High Energy absorption of the shotcrete liner
Trouble free application of the shotcrete

Sika's market-leading Sigunit® and Viscoflow® technology are key for the shotcrete and concrete works at the Fresnillo operations. Highly effective and versatile dry shotcrete mixes and powder accelerators are used at different mine sites. At the Fresnillo operations, wet shotcrete is applied mainly by SPM 4210 wet spray rigs. The dry mixes are sprayed using Sika Aliva rotary machines. For the shotcrete, the mine relies on the proven Sika Fiber® technology with excellent load-bearing capacity at a low fiber dosage.

Sika is involved with a number of special projects such as lightweight concrete for void filling and HPC concrete for special reinforcement and ground slab designs. As the concrete is supplied by a batch plant outside the mine perimeter, the long transport and haulage distances to the point of use require effective retardation of the concrete and hence well-adjusted mix design using powerful Sika admixtures. Sika is at the forefront when implementing best-demonstrated mining practices from case studies around the world with its customers and is sharing this knowledge frequently with Fresnillo and DICOM.

Sika Viscoflow® superplasticizer / slump retainer
Plastiment liquid consistency stabilizer
Sigunit® L50 AFX alkali-free, high-performance shotcrete accelerator
Sika Fiber® polypropylene macro-fiber
Sika PM 4210 wet shotcrete spray units
Sika Aliva Dry spray shotcrete equipment