Tag Archives: Buriticá

Doppelmayr ropeway tackles mine backfill task at Buriticá gold operation

A Doppelmayr ropeway is now up and running at the Buriticá underground gold mine in northwest Colombia, navigating mountainous terrain to transport backfill material from the bottom of the valley to the mouth of the mine.

In October 2017, Austria-based Doppelmayr was awarded the contract to build a 1.4 km long ropeway with material buckets for a transport capacity of 175 t/h. The system was conceived as a continuous bi-cable ropeway, with a fixed tensioned track rope for the material buckets with their carriage to travel on. The buckets are driven by the continuously moving haul rope loop to which they are attached via detachable grips.

The area where the mine, owned by Zijin Mining, is located is mountainous and therefore logistically challenging. The reusable residues of the gold extraction process are used as underground backfill, which is why they must be taken from the bottom of the valley to the mouth of the mine at 1,700 m above sea level, thereby covering a difference in altitude of approximately 646 m. What would be an arduous and long journey for trucks, with plenty of exhaust emissions, becomes a swift and efficient job if a material ropeway is used, Doppelmayr says.

To allow for the haul rope to be run at a constant speed, the buckets are detached from the loop in the stations and slowed down before they are loaded via a chute. Once a bucket has been filled, it is accelerated to running speed again and re-attached to the haul rope before leaving the station.

In the unloading station, the bucket is once more taken off the haul rope. At the designated unloading point a special mechanism unlocks the latch on the bucket, the bucket is tipped, and the material is safely transferred onto another chute. The bucket then returns to its original position. It is locked again and re-attached to the haul rope before travelling back into the valley empty.

In the past, continuous bi-cable ropeways have often been used for material transport applications, the company explained.

“For the Buriticá project, Doppelmayr’s engineers have revised the design and mechanics of continuous bi-cable ropeways from scratch and optimised it for the transport of material in buckets,” it said. “The system complements Doppelmayr’s portfolio of material transport solutions.”

Put into service in February 2021, the solution has a transport capacity of 175 t/h of gold residues, a running speed of 6 m/s, and comes with 20 carriers and one tower.

TERRATEC helps bring fresh air to Buriticá gold project

TERRATEC has celebrated the successful completion of a 300 m deep, 4.1 m diameter ventilation shaft at the Continental Gold-owned Buriticá gold project, in Colombia.

Peruvian mining contractor INCIMMET deployed a custom-built TR2000 Raise Boring Machine (RBM) to excavate the shaft in what TERRATEC said were challenging ground conditions. This put the machine through its paces during its first bore at the mine, the company said.

Located approximately two hours’ drive northwest of Medellin, Buriticá is a large high-grade gold deposit encompassing an area of about 75,000 ha in Antioquia. 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 by the Colombian government, in November 2015. When in production, it is expected to be Colombia’s largest gold mine, producing 253,000 oz/y of gold. First gold is expected by the end of the year, according to Continental.

TERRATEC said: “Arguably the biggest challenge for the mine development project is the area’s geology. Ground conditions at the Buriticá complex largely consist of andesite-porphyry, diorites and monzodiorites with intrusive hydrothermal gaps within the volcanic and sedimentary sequences. These mixed and fractured conditions provided a challenge both to the integrity of the reamer and the capability of this robust machine.”

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 in this difficult terrain, according to the company.

“Not all raiseboring equipment is capable of working with such robustness in these conditions,” TERRATEC Regional Raiseboring Operations Manager, John Alejos, said. “Without doubt, this changing terrain is almost impossible to drill at such depths and such diameters. Only a team as strong as this, with the technical support of our on-site staff, is able to carry out such a task successfully and not without difficulties.”

Custom manufactured at TERRATEC’s workshop in Tasmania, Australia, the TR2000 RBM was designed for ease of operation and maintenance, while providing a high level of reliability. The unit is designed to “comfortably” execute raises of up to 500 m at 2.4 m diameter and larger ones up to 4.1 m diameter (of shorter depths), according to TERRATEC. It has a maximum pilot drilling torque of 42,000 Nm, a reaming torque of up to 209,000 Nm and breakout to 236,000 Nm. The maximum down thrust force is 665 kN with upthrust being 4,150 kN. The total installed power on the machine is 360 kW.

TERRATEC has numerous machines currently working in the Americas in Canada, USA, Mexico, Colombia, Peru and Argentina. These include the company’s entire range of vertical mining drilling equipment, including RBMs, Down-Reaming Machines and Box Holing Rigs, as well as a combination of these in the form of Universal Boring Machines.

Continental Gold keeps Buriticá project on track for debut pour in H1 2020

The latest update from Continental Gold on its Buriticá project in north-western Antioquia, Colombia, indicates the company is on track to pour gold in the first half of 2020.

The company said overall construction was 44% complete, with detailed engineering over 93% advanced.

At the same time, underground development was tracking ahead of plan at 44% completion, with 6,274 m finished to date. Process plant earthworks were 76% finished and mechanical installation was scheduled to begin in early 2019, the company said, while powerline installation was advancing rapidly and set for completion early in the September quarter.

This all bodes well for commercial production ramp-up of Buriticá taking place six months after the first gold pour.

Since completing the feasibility study for the Buriticá project in 2016, the company has been optimising the mine design and rescheduling development. This work has resulted in a reduction in total pre-production lateral development (horizontal and inclined jumbo development) from 19 km in the feasibility study to 14.3 km in the current mine plan, a reduction of approximately 25%.

In terms of underground development, monthly advance rates have consistently exceeded planned development this year. Crews continue advancing daily at the Yaraguá and Veta Sur ramps and the Higabra tunnel and upper and lower drifts connecting the Yaraguá and Veta Sur vein areas are advancing well. Additionally, definition drilling continues to provide information required for stope design and mine production scheduling.

Drill chambers continue to be extracted proximal to planned stoping areas as development advances; monthly definition drilling has been and will continue to increase through the balance of the year and into 2019 as development accesses additional drilling areas, the company said.

The feasibility study for the Buriticá project highlighted the potential to host an economically robust, high-grade underground gold mine, which includes a mineral reserve for the combined Yaraguá and Veta Sur vein systems totalling 3.7 Moz of gold and 10.7 Moz of silver at grades of 8.4 g/t Au and 24.3 g/t Ag. When in production, it would be Colombia’s largest gold mine, producing 253,000 oz/y of the yellow metal.