Laser clad wear-resistant titanium hardfacing
Corrosion and erosion are major challenges in the mining industry’s high pressure acid leaching (HPAL) environment to separate nickel from laterite ores. The process involves mixing crushed ore, water and concentrated acid at elevated temperatures (255° C) and pressures (725 psi) to create a slurry in an autoclave vessel. The slurry is then washed and the nickel recovered. In these conditions, agitator blades are exposed to a combination of high shear, tip speed and temperature, in the effective mixing of abrasive solids, acid and solution. Increasing the service life of these blades will reduce shutdowns and lower production costs.
Brenco worked with the mining operation to understand the wear characteristics of the agitator assembly. This understanding enabled Brenco to develop a proprietary hardfacing solution—a laser clad titanium—which was put to the test in a 16-month trial campaign.
In Campaign 1, Brenco applied 3 mm of their proprietary laser cladding to the high wear areas of the agiator blades, and the impeller was installed in an HPAL autoclave compartment. An unplanned shutdown seven months later allowed an inspection of the blades, which were still in good operational condition.
In Campaign 2, as a trial comparison, an impeller with 5 mm PTA-applied Ti-Ox reaction overlay from a competitor was installed in the adjacent compartment of the same autoclave. The Brenco impeller was also put back into service.