The following case study details the use of Pilbara Standards’ coarse CRM in identifying the malfunction of a crusher.
This example showcases the effective use of coarse CRM in identifying sample preparation performance, and demonstrates the effective use of control charts to monitor performance over time, in conjunction with thorough record-keeping.
Pilbara Standards’ expertise and experience in the manufacture of CRM for the iron ore mining industry provides our clients with peace of mind.
Our client runs an automated laboratory preparing fusion XRF analysis of iron ore, and sought the assistance of Pilbara Standards in supplying coarse CRM to monitor crusher performance.
In the analysis of iron ore samples by fused bead XRF, course CRMs are used to monitor the entire system: from sample preparation, to bead fusion and XRF analysis.
The graphs below display data for Fe, SiO2, Al2O3 for a coarse CRM run daily through a three-crusher sample preparation system.
These charts show four samples – numbers 7, 10, 13 and 16 – failing with high Fe, i.e. greater than expected value + 3 times standard deviation of expected value.
The same samples also fail at the low end for both SiO2 and Al2O3.
The fines of this CRM are known to contain elevated concentrations of both SiO2 and Al2O3 compared to that of the entire sample.
Interrogation of the prep logs showed that all of the samples failing QC passed through the same crusher – No.2.
Investigation of this crusher showed that a valve was damaged and not fully closing while processing the sample, causing loss of fines in the sample, leading to depression of SiO2 and Al2O3 and elevation of Fe.