It isn’t uncommon to have various problems that could be associated with machinery and equipment in the mining industry. The environments in which they operate can be incredibly harsh often leading to the need for repair and maintenance. A primary crusher is a great example of a machinery subject to the effects of harsh environment.

In a past blog, Mining & Quarrying: Belzona’s Top 5 Application Areas, we highlighted the common issues associated within the mining industry.

These include:

• Abrasion
• Chemical Attack
• Corrosion
• Impact
• Wear

These can all have a major impact on processing and productivity. Ultimately leading to a shutdown and costly downtime.

A common cause of wear can be vibration. This can cause eventual fatigue, resulting in cracks and a loss of material. Inherent vibration from the operational equipment can cause premature failures in areas such as concrete foundations and their anchoring systems. Generally speaking, concrete can be considered too brittle and weak to absorb such constant impact and vibration transferred from the equipment. Once the concrete has failed, anchor bolts in the foundations can loosen, further aggravating the effects of the vibration on the foundation.

A copper mine in Marabá, Brazil, found this to be the case with their primary crusher. The base of the primary crusher needed to be rebuilt due to being weakened by vibration. The primary crusher weighs 336 tonnes and is 9.5 metres high and 5.6 metres wide, contributing further to the amount of stress being put on the foundations.

Continuing under such damaged conditions would have eventually led to serious consequences, including a significant financial loss. A solution was required that could rebuild the foundation and bases of the primary crusher, whilst being able to withstand high dynamic and impact loads without shattering and breaking. Excellent mechanical properties and a fast curing time were also critical in ensuring the primary crusher would return back to service in as little time as possible. The solution presented was Belzona 4111 (Magma Quartz), a high-performance concrete repair and rebuild composite.

Using an impact hammer drill, the first two layers of concrete were removed to reach the steel reinforcement structure. Particularly with concrete repairs, surface preparation is critical in its success. The substrate needs to be free from contamination, free from excess moisture and any loose material needs to be removed. The area was therefore cleaned and degreased with solvent and compressed air was used to remove the entire repair area of loose debris and dust. Belzona 4911 (Magma TX Conditioner) was then applied to ensure an optimum bond between the substrate and repair materials.

The perimeter of the repair area was initially built up, later acting as a mould for a slurry mix of Belzona 4111. The material was able to level evenly to recreate a foundation at the base of the primary crusher. The implemented solution offered resistance to high vibrations and dynamic loads due to its high mechanical strength. The excellent adhesion of the system to both metal and old concrete allowed for a homogeneous load distribution, without weak spots during the anchoring/grouting procedure and service.

The curing time of the system allowed the assembly of the machine to commence in as little as 4-6 hours after application and a full return to service was possible in approximately 16 hours. The fast turnaround time allowed the copper mine to continue its processes without a majorly disruptive or costly downtime. The chosen solution allows for long term protection, as opposed to a quick fix with a lower quality and a significantly shorter life.

Since the application, the repair continues to perform well and was visited a few months after the application. Hita Comércio e Serviços Ltda, the Belzona Distributor in Brazil, has performed over 100 foundation and anchor bolt repairs in the past 3 years using a Belzona 4111 mould/slurry mix solution.

Despite the harsh environment the repair is facing, it is still fulfilling expectations, showcasing the long-term solutions Belzona can offer over cheaper “quick-fix” repair methods.

Hita Comércio e Serviços Ltda is a Belzona Authorized Distributor, supplying solutions and services across Brazil with a team of more than 35 technical consultants. Since founding in 1995, Hita have been providing engineering solutions across several industries such as Mining, Oil and Gas, Petrochemical, Marine and many more.

The consulting team associated with the application consisted of:

• Wilson Santos – Mechanical Technician/Coordinator
• Eder Sacramento – Electromechanical Technician/Consultant
• Matheus Werten – Civil Engineer/Consultant

In the video below, Belzona’s polymeric concrete repair and protection solutions are put to the test to demonstrate their capabilities.