Incimmet completes tough ventilation shaft

1 October 2019

Colombia – Peruvian mining contractor Incimmet has excavated a 30m-deep, 4.1m-diameter ventilation shaft for the Buriticá mine development project. Ground conditions at the Buriticá complex largely consist of andesite-porphyry, diorites and monzodiorites with intrusive hydrothermal gaps within the volcanic and sedimentary sequences.

A spokesperson said that the mixed and fractured conditions challenged the integrity of the reamer and that mineralised gaps, which are frequently associated with the development and alteration of clay minerals, required constant monitoring of the excavation and appropriate advance rates to provide good progress.

The machinery chosen was a Terratec TR2000 raise-boring machine designed to execute raises of up to 500m at 2.4m diameter and larger ones up to 4.1m in diameter, but to shorter depths. It has a maximum pilot drilling torque of 42,000Nm, a reaming torque of up to 209,000Nm and breakout to 236,000Nm. The maximum down thrust force is 665kN with upthrust being 4,150kN. The total installed power on the machine is 360kW.

Located approximately two-hours northwest of Medellin, Colombia’s second-biggest city, Continental Gold’s flagship Buriticá mining complex is one of the world’s largest remaining untapped high-grade gold deposits, encompassing an area of about 75,000 hectares in the Antioquia Department. The mining complex, which is in the early stages of development, is Colombia’s first modern underground mine and was designated as a Project of National Strategic Interest (PINES) by the Colombian government, in November 2015.