Barrick turns to Belzona for coating solution on Pueblo Viejo slurry tanks

The mining industry is notorious around the world for its difficult operational conditions which require specialist equipment to suit the environment. This can include both big, heavy machinery for extracting ores and minerals, and also complex equipment to process and purify them. To maintain the integrity and longevity of these assets, specialised coatings are applied to machinery and equipment.

The world’s largest gold mining corporation, Barrick Gold Corp, recently turned to Belzona solutions to repair and protect a slurry tank in their Dominican Republic mine, Pueblo Viejo. The slurry tanks are a crucial part of the separation and purification process of gold from the mined ore. This particular tank was used to neutralise acidic sludge to a higher pH but was performing inefficiently due to its high levels of erosion-corrosion.

Corrosion was developing from a number of sources including the tank’s high temperature, abrasion (from rocks and abrasive sludges in the slurry), bacterial attack and chemical attack. Ultimately, the mine’s corrosion engineers did not know how to counter all of these damage mechanisms. Moreover, time was of the essence as some of the other slurry tanks’ flooring were already failing due to similar circumstances.

One option considered was to install a rubber lining to the slurry tank’s interior, however, logistically this was far from a simple application. It was then that a Belzona system was suggested to the corrosion engineers as an alternative solution. This system comprised:

  • Belzona 1121 (Super XL-Metal) – a versatile, paste-grade, epoxy material for rebuilding the damaged areas of the slurry tank
  • Belzona 1381 – a solvent-free material designed to operate under continuous immersion of up to 95°C (203°F) which would be used to coat the tank and provide ongoing erosion resistance and protection

Not only did this system meet the operational conditions but it was also three times less expensive than the cost of the rubber lining. Beyond this, the Belzona 1381 could be spray applied, making it easy and quick to coat the whole 940 m² (10,118 ft²) surface. The Pueblo Viejo Mine was no stranger to Belzona, having previously used several solutions to repair pumps, secondary containment areas and damaged concrete. Therefore, they knew they could rely on Belzona materials’ capabilities and durability.

Another reason Belzona was chosen was because the mine’s engineers had never performed such a large spray application before, and therefore it was decided that members of Belzona’s Technical Department would be present throughout the project. Beginning on the 8 April, Belzona was given a 20-day time frame to complete the specified application. This began with grit blasting to prepare the tank’s surface, however, soon heavy rain prohibited blasting because there was a risk it would cause the metal to rust. Additionally, one of the mine’s security protocols stated that every time there was lightning, work was required to be halted immediately for two hours.

The fast cure times and ability to be complete within 20 days was one of the main selling points of the Belzona system and so the members of the Technical Department on site were eager to complete the application. But continuous stormy weather meant that only minimal amounts of work were possible at a time.

Another issue arose when it was discovered that the base and floor of the tank had experienced more severe pitting and deterioration than previously expected. However, because of Belzona 1381’s excellent protection against erosion-corrosion, when coating the second layer, only a thicker build was applied near to the damaged areas to restore them.

When the weather finally cleared on the 24 April, the spray application was able to commence. With only four days until the 28 April deadline, the entire slurry tank was sprayed including the areas where a second coat was required.

After the application, the customer was highly impressed with Belzona both in terms of the materials and support from the Technical department. Despite the problems faced, the system was installed within the 20 allotted days thanks to the fast spray application and is so far performing perfectly.

Noelia Diaz Tavarez, an Asset Integrity Engineer at the mine, stated that: “For technical support, Belzona has been one of our best partners to date on information, support, improvements and applications. In this particular case, these were key factor for the execution of the work on time. As of August, we are fully confident in the products.”

Going forward, the Engineers at the gold mine have stated that Belzona will be their first choice for repair and protection projects, and already a second slurry tank has been coated with a Belzona system. The mining industry can be a difficult industry to protect against but once again Belzona has proven itself to be a golden solution.