ima engineering

What is the ore grade in the loading piles today? Which piles to feed into the crusher and at what ratio? These are among the questions a miner asks themself every day. Can we trust grade control estimates of the muck piles?

Blasted ore grade is not always as estimated, but no worries, IMA can now offers a solution for every miner and a grade control geologist.

A new version of IMA Innovative Mineral Analyzers’ fast conveyor analyzer, the FCA, will analyse ore grade accurately at the first crushing stage. Primary crushed ore with a lump size of up to 400mm does not affect the analysis, and the analysis is instant minute-to-minute, so each dumper load is analysed accurately.

The new FCA analyser system shows the analysis results on a trend in the control room. It sends an alarm to the grade control geologist’s mobile phone if ore lower than the cut-off enters the crusher.

The grade in the piles can be checked anytime from the instant trend display, also 30mins, 1h and longer time averages are calculated. Run of mine ore in piles can be verified by dumping two loads into the crusher and then by checking the grade from the trend, easy and fast (real-time analysis in minutes).

The beauty of the new FCA analyser is its simplicity when installing and calibrating. The performance was tested in a copper mine after the FCA was installed on a conveyor (ROM ore with -250mm top-size) before the grinding mills and flotation cells, where the mine already had an OUTOTEC CourierTM installed analysing the flotation feed.

The FCA and CourierTM analysis was monitored and compared for several weeks. Correlation of the two analyser systems was at 92% for copper.

Based on shift averages, the mine can calculate half-month and full-month averages for reconciliation, which can also be checked in real-time.

Should there be a need to calculate the averages in the muck piles or ROM piles, this can also be done based on the FCA readings.

One dump load (200t) goes through the crusher in ten to 12 minutes and each time the dump grade can be seen from the screen. It is very easy to prevent the wrong ore type from getting into the crusher.

Image: The grade in the ore piles can be checked in real-time. Photo: courtesy of IMA Engineering.