Controlling the final product with sampling

FLSmidth worked in conjunction with the Andina Division to design a revolutionary dual sampling system (DSS).

The Andina Division is the second most important copper producer for the Codelco Chile corporation. One of the main challenges for the plant is to effectively control the final copper product from the concentrates collected in the plant’s filter and warehouse.

To overcome the challenges of conveyor speed, space conditions, final product transport and reduced distances, FLSmidth worked in conjunction with the Andina Division to design a revolutionary dual sampling system (DSS).

The project was centered on replacing the current materials transport system with an automated system that would allow the plant to quantify the weight and grade of the concentrate before being dispatched to the port of Ventanas. Copper is the primary product of the Andina Division. The highest margin of error for calculations with the new system was 1% for 9-ton maximum weight containers with less than 50-second fill times. Weighing tables were linked to the equipment’s control center to ensure that the maximum weight of each container was not exceeded.

A weight meter was installed for each conveyor belt based upon its load capacities. The dual sampling system was then attached, enabling a single system to operate the sampling automatically when one of the two conveyor belts was running.

In the test phases of the new system, samples were taken by the dual cutter approximately every 60 seconds. That meant that for every 720 metric tonnes the equipment would take eight samples according to the 930 MT/h flow. With eight samples per lot, the margin of error was reduced to 0.18%
Using EMPV (effective management process variability) statistic software, the data from the chemical analyses and physical determinations of the samples were processed. The calculations showed that the average copper percentages of the final product was between 28.4% and 28.2%.

The ability to control and track ore grades is crucial to the client for product traceability and international sales departures. By using this new dual sampling system, FLSmidth was able to more accurately calculate the metallurgic balance of the final product for the Andina Division, both on site and at the port.

CONTACT: Vicente Esparza