The mining method currently used by Codelco’s El Teniente Division for the extraction of the ore body (Panel Caving), facilitates the filtration of surface water that accumulates in subway productive sectors. These tend to flow towards the extraction points increasing the percentage of humidity of the mineral in a range of 5% to 10%. The mentioned condition generates an adverse impact on the transfer systems, since the fine material tends to compact, consolidate and even cement on the walls of the ore pass and hoppers, resulting in the phenomenon known as “blockage”. The ore pass have a free diameter of 3 meters and up to 30 meters in length, including a vertical section of 25 meters and a subvertical section of 5 meters with an inclination of 40°. The ore pass are internally reinforced with a layer of concrete followed by steel. Each transfer system could have a maximum flow rate of 4,000 tpd, and the maximum size of a rock could be 1 meter long (reference information). The ore pass has access both from the upper part, at the production level, and from the lower part, at the transport level, through the unloading bin, a mechanical structure for loading and unloading trucks. In the north mine there are more than 40 ore pass systems, but the ones with relevant blockage are in the order of 10%.

Permanently, due to the increase in the percentage of humidity of the mineral.

Lower rate of ore pass unloading to the haul truck due to reduced section in the ore pass, leading to non-compliance (or non-adherence) to the production plan. Operational stoppage of the pit for ore pass blockage, in one or more shifts, leading to non-compliance with the production plan. Possible exposure to people due to ore pass unblocking tasks.

Through mechanized tools.

Mechanized tools, explosives, water.

– Consultancy, advice and engineering studies. – Solutions that do not prevent the formation of blockages and/or do not unblock the already affected ore pass.

Preventing the formation of blockages and/or unblock of underground mining ore pass and hoppers at Codelco’s El Teniente Division, which transport primary ore. The problem is generated due to the filtration of surface water that accumulates in productive sectors, increasing the percentage of humidity in the ore in a range of 5% to 10%.

1. The solution must prevent the formation of blockages and/or unblock of already affected ore pass.

2. Solution should mitigate or eliminate the exposure of people to risks.