Comparison of some laboratory wear tests and field wear in slurry pumps

Abstract

A number of different laboratory wear tests have been undertaken to measure the wear resistance of a natural rubber and a eutectic and hypereutectic white iron under abrasion and erosion conditions. Laboratory work included two different slurry jet erosion tests, a Coriolis test and an ASTM dry sand rubber wheel test.The laboratory results were compared with wear of the same materials in a centrifugal slurry pump application in a mineral processing plant. The pump application has been monitored for over 2 years and over 40 parts run to destruction. Analysis of the wear data shows a factor of almost 3 difference in wear rate between the rubber and the best white iron. Coefficient of variance of the data was in line with typical wear results from the field.The laboratory wear tests were conducted with a silica sand slurry and average particle size range of 300–500μm to match the field conditions. The Coriolis and one of the jet erosion tests showed order of magnitude similarity with the field test results for the metals, but the other tests gave very different trends. The jet and Coriolis erosion tests on the rubber showed a much lower wear rate than seen in the field, while the DSRW test found that the eutectic white iron wear rate was lower than that of the hypereutectic iron (all opposite of the field test).Explanation for the different wear rates between the laboratory and field tests was postulated to be non-representative wear mechanisms. This is compounded by the lack of understanding of specific wear conditions in the pump (local velocity, concentration, particle size, size distribution and particle shape) as well as microstructure of the samples.