Restoration and Protection of Equipment and Metal Structures
RECONSTRUCTION AND STRENGTHENING OF DRUM BALL MILL BODIES, VENTILATION DUCTS, METAL STRUCTURES, AND OTHER EQUIPMENT TO DESIGN STANDARDS USING FRP AND ULTRA CERAMIK LINING SYSTEMS
MShTs-type mills are used for grinding ore to sizes suitable for extracting valuable minerals from the overall rock mass. The primary protection of the mill bodies, including the main cylinder and end walls, is provided by standard protective elements designed to minimize the impact of shock and dynamic loads. However, these elements cannot protect the metal body from erosion, cavitation, corrosion, and abrasive wear from fine particles. The continuous production process complicates timely inspection and assessment of wear, as well as performing scheduled maintenance.
The Weartech LLP team has integrated the FRP strengthening system and Ultra Ceramik lining to restore the original strength of metal structures and protect them from abrasive, corrosive, and chemical damage.
Developed by engineers, the system is designed to reinforce metal structures. It includes high-strength composite materials with excellent tensile strength and elasticity, as well as high adhesion to the reinforced surfaces, preventing delamination. The system uses carbon fiber with a tensile strength of at least 4850 N/mm² and an elasticity modulus of at least 230,000 N/mm².
In laboratory tests with I-beams No. 10 (st. 3ps), non-reinforced samples were compared with those reinforced with carbon fiber. The maximum load at which strength was maintained was 76 kN. In an experiment with a 75 kN load, the non-reinforced beam showed a maximum deflection of 8.21 mm (critical at 8.33 mm), while the carbon fiber reinforced beam had a deflection of only 3.97 mm.
Based on the above, the application of a single layer of the reinforcement system up to 3 mm thick increases tensile strength by 48-50%. Moreover, even with increased mechanical loads, defects in the form of delamination or peeling were not observed.
The reinforcement system components include:
- High adhesion primer for polymers;
- Two-layer high-strength putty to protect the carbon fiber;
- Medium-density epoxy adhesive for reliable carbon fiber bonding;
- Epoxy resin saturation of the carbon fiber to increase the strength and rigidity of the structure;
- Finishing high-strength putty to protect the fiber structure.
Ultra Ceramik Lining System
The Ultra Ceramik lining system consists of tiles made from zirconium and aluminum oxides, measuring 20x20 mm and at least 4 mm thick. Thanks to their compact size, impact and dynamic loads are evenly distributed across the surface, reducing the likelihood of damage.
The tiles, based on zirconium oxides, are highly resistant to abrasive wear, as well as corrosion and chemical attacks.
Tile installation is carried out using a special thixotropic adhesive with high adhesion to polymers, ensuring the integrity and monolithic nature of the coating.
The advantages of the proposed reinforcement and lining systems include:
- The ability to perform quick repairs using cold welding methods, reducing costs and equipment downtime.
- Strengthening and protecting casings, extending their service life compared to traditional repair methods using overlay welding.
It is important to note that the overlay welding method does not restore the load-bearing capacity of the structure, but only increases the wall thickness, maintaining the risk of further wear and increasing overall equipment operating costs.