When Anglo American Platinum’s Mogalakwena mine in South Africa’s Limpopo province wished to increase the damage lifetime of shaft sleeves in its Warman® pumps, Weir recommended the applying of the J221 premium wear-resistant overlay hardened shaft sleeve.
Testing was carried out on a Warman MCR® 450 slurry pump on the North Concentrator to enhance sleeve and packing put on life underneath situations of contaminated or sub-optimal flush water. The J221 shaft sleeve’s trial efficiency was distinctive, lasting 14,240 hours underneath situations of each common operations and intensive pump sliming, Weir famous. This was an nearly 10-fold enchancment on the usual shaft sleeve. The answer has led to financial savings in each downtime and spare elements.
Following the profitable outcomes, LeRoux Esterhuyse, Engineering Supervisor on the Mogalakwena North Concentrator, reported: “Excited concerning the trial efficiency of the hardened shaft sleeve; allow us to roll it over to all major and secondary mill discharge Warman pumps.” The J221 sleeves have since been applied throughout all major and secondary mill discharge pumps at Mogalakwena.
Because the world’s pre-eminent open-pit platinum mine, Mogalakwena prides itself on its low working prices and its dedication to initiatives that bolster throughput whereas curbing bills. Platinum ore mined on the varied Anglo American Platinum operations is milled on the new Mogalakwena North Concentrator – in operation since 2007 – and the older Mogalakwena South Concentrator.
The problem confronted was that the first and secondary mill discharge pumps – a mixture of Warman AH® 20/18 and Warman MCR 450 slurry pumps – had been being overhauled ceaselessly as a result of excessive put on on the C23 shaft sleeves. The pumps needed to be stopped month-to-month to vary out the shaft sleeve, with providers carried out by the Weir on-site service group. Weir has had a service settlement with Mogalakwena Complicated – comprising the Mogalakwena North and South concentrators – for 14 years, with a area service group reporting day by day to each websites.
The Weir group decided that the damage lifetime of the C23 shaft sleeve was 3,864 hours underneath customary working situations and just one,440 hours underneath situations of intensive pump sliming. This happens when there’s insufficient gland water stress within the pump stuffing field, inflicting slurry to breach the packing between the shaft sleeve and the packing rings.
When the gland packing is compromised like this, the slurry erodes grooves into a normal shaft sleeve. As soon as these grooves develop, the packing can not kind an efficient seal on the shaft sleeve. This example requires the shaft sleeve to get replaced, decreasing the tools’s availability.
The J221 premium wear-resistant overlay is right for extremely abrasive and erosive put on setting, as a result of excessive density of the tungsten carbide particles within the matrix. The overlay boasts uniform carbide distribution with low porosity, and hardness ranges as much as 70 HRC, Weir says.
