Ore Logwasher Scrubbing Baths.

Logwasher scrubbing baths are used in magnesite processing to break down and remove clay, soil and other surface contaminants from the mined ore before further crushing, screening or beneficiation. Counter-rotating paddle shafts agitate and scrub the material within the bath, creating attrition between particles and separating softer waste from the harder magnesite.

The system must maintain controlled material flow and retention time while withstanding high torque, heavy impact loading and continuous abrasive service.

MEA has supported QMAG's Kunwarara Mine for more than 30 years with the maintenance, refurbishment and continuous improvement of its magnesite logwasher scrubbing baths. Initially engaged to supply replacement paddle shafts, MEA's involvement has progressively expanded to include the engineering, manufacture and refurbishment of the major mechanical components and supporting structures for the complete logwasher system.

Through ongoing inspection, failure analysis and operational feedback, MEA has implemented numerous design and material improvements aimed at increasing component service life and reducing unplanned maintenance, completing the design and manufacture of paddle shaft assemblies, timing bull gears, flame-hardened drive pinions, reduction gearboxes, drive motors, grease-box covers, cast paddles and associated structural components.

One of the most significant projects involved the complete redesign of the logwasher non-drive-end stub assemblies, which had required refurbishment as frequently as every two months due to severe contamination ingress and repeated bearing failures. MEA developed a new arrangement incorporating positive grease displacement to continuously purge contaminants away from the bearing cavity and provide an effective barrier against water, clay and fine ore particles, along with forged stub shafts, improved wear-resistant interfaces, brass-cage bearings, revised bearing selection and fully machined bearing housings.

These combined improvements have dramatically increased the service life and reliability of the assemblies, reducing refurbishment frequency and improving the overall availability of QMAG's logwasher operations.