Tag Archives: Belzona

Belzona provides long-term protection at Australia uranium operation

Belzona has helped a uranium mining operation in Australia protect its exchange vessels using corrosion resistant epoxy coatings and repair composites.

The operation, which uses a unique extraction technology to produce high purity uranium, was after a solution with good chemical resistance that was able to withstand high operating temperatures after, a planned upgrade revealed issues with the existing rubber lining of the exchange vessels.

The lining failure had caused corrosion of the steel substrate (which had continued to go unnoticed behind the rubber) and now had the potential to severely impact production and ultimately shut them down completely, according to Belzona.

“The exchange vessels measure at around 2.5 m in diameter and 5 m in height and are considered the lifeblood of their business,” Belzona said. “The process conditions meant that there was a strong chemical presence and high operating temperatures further contributing to the corrosion of the lining.”

Two of the vessels were able to be viewed, due to being out of service, helping to understand the process conditions.

The existing rubber internal lining had to be removed using a high temperature, ultra-high-pressure jet water operating at 150°C and 40,000 psi pressure. This stripped back the rubber lining, leaving a bare steel shell with only small amounts of rubber remaining. This was then whip blasted and any sharp angles, burrs and weld defects were identified and prepared to a minimum R5 radius suitable for coating, according to Belzona.

Following on from the pre-surface preparation, the vessel was degreased using high-pressure water jetting at 6,000 psi followed by a solvent wash using MEK before being blasted.

Before the new internal linings were applied, nozzle inserts were fitted with a stripe coat of Belzona 1391T to the circumferential welds and bracket details. Nozzle inserts manufactured using Belzona 1511 (Super HT-Metal) were initially dry fitted into the appropriate nozzle where they were then marked and cut to size before being bonded in place using Belzona 1391T.

Small areas of pitting around the welds were filled at the same time and allowed to cure. After the required length of time and within the overcoat window of Belzona 1391T, the stripe coat was applied to the welds and large nozzles. Spraying of the new internal linings began once the stripe coatings were cured.

Belzona said: “To provide a full turnkey solution without any delays, blasting of the second vessel began whilst the first vessel was being coated. The original coating was then left to cure overnight with a second coat to follow the next day. Heat was applied to the vessels to assist in providing a fast cure time and return to service.”

Thanks to effective time management throughout, the overall application was able to be completed very quickly, with each vessel taking a few days to complete, Belzona said. The vessels have now gained long-term protection against corrosion and a longer service life.

Belzona 1814 to protect chutes, hoppers and screw conveyors

Belzona has released a new epoxy-based material to, it says, resist the harshest abrasive environments typically found in the mining, cement, pulp & paper, biomass and other industries.

Belzona 1814 can be applied with a brush or a float to protect assets preventing metal loss and subsequent downtime, either on its own or as part of a system with alumina tiles, the company says.

Supplied in 30 kg units, compatible with mechanical mixers and boasting a long working life, Belzona 1814 is most suited for application to large assets, including chutes, hoppers and screw conveyors, according to Belzona.

Belzona R&D Manager, Jason Horn, said: “There was a need for a lasting abrasion protection system, which can be easily mixed in large volumes and applied over sizeable areas.

“Our second objective was to create a formulation with performance equal to our existent abrasion resistant materials, while keeping the costs down – the benefit of which could then be passed onto our end users.

“We believe, with Belzona 1814, we have produced a high performance and cost-effective system.”

Belzona reinforces crusher foundations at Brazil copper mine

Belzona has used its own concrete repair and rebuild composite to keep a primary crusher operational at a copper mine in Brazil.

A common cause of wear in the mining industry can be vibration. This can cause eventual fatigue, resulting in cracks and a loss of material in operational equipment. It can also lead to 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,” Belzona said. “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 its primary crusher, according to the company, with the base of the primary crusher needing to be rebuilt due to weakening caused by vibration. The 3,000 t/h primary crusher weighs 336 t, is 9.5 m high and 5.6 m wide, contributing further to the amount of stress being put on the foundations, Belzona said.

“Being one of the biggest copper crushers in South America, and with copper being traded at around $6,000/t, every hour of shutdown can result in a loss of almost $20 million,” the company said.

A solution was required that could rebuild the foundation and bases of the primary crusher, while being able to withstand high dynamic and impact loads without shattering and breaking, according to Belzona. “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 used 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,” Belzona said. ”The substrate needs to be free from contamination, free from excess moisture and any loose material needs to be removed.”

The area was cleaned and degreased with solvent and compressed air was used to remove the entire repair area of loose debris and dust. A 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, according to Belzona.

“The implemented solution offered resistance to high vibrations and dynamic loads due to its high mechanical strength. The system adhered to both metal and old concrete allowing for a homogeneous load distribution, without weak spots during the anchoring/grouting procedure and service,” the company said.

The assembly of the machine to the structure commenced in as little as four to six hours after application, according to Belzona, with a full return to service possible in some 16 hours.

“The fast turnaround time allowed the copper mine to continue its processes without a majorly disruptive or costly downtime,” the company concluded.

Specialising in erosion, corrosion and chemical protection, Belzona calls itself a world leader in the design and manufacture of repair composite materials and protective coatings for machinery, equipment, buildings and structures.