In the previous post, we discussed how the design of the MHC series helps to balance cost and performance of a grinding circuit. But how does it apply to a real-life operation? Based on extensive market research and industry feedback, the MHC Series Hydrocyclone was developed focusing on delivering improved process performance and maintainability. To make sure the designed features meet the targeted results in production, we launched an extensive validation process covering various hydrocyclone sizes and applications in both pilot and field trials.
Validating the design in a laboratory environment
The laboratory testing was performed in the Metso York Laboratory in Pennsylvania, US. The targets for the initial testing were to evaluate efficiency, sharpness, fines bypass, and cut size for a homogenous ore type (limestone).
The results from the laboratory test indicated very encouraging performance from the MHC internal geometry. At a reasonable operating pressure of 124 kPa, the cut size on a 250 mm hydrocyclone is below 30 microns. When operating in this condition, the cyclone efficiency is almost 90%. Efficiency is defined as the mass percentage of product size in the hydrocyclone feed that reported to the overflow (product size defined at the 80% passing point of the overflow).
Moment of truth in field trial
For the field trial, a Metso MHC650 (650 mm diameter) was installed in the grinding circuit at a copper concentrator in southwestern US in 2016. The goal of testing a production unit in a large-scale copper mine was primarily for wear component prototyping and continued process data collection.
Various grades of rubber and polyurethane have been tested within the different hydrocyclone components. Ceramic inserts into polyurethane was first introduced as an apex insert, and secondly at the bottom of the conical section. The ceramic components are still in operation and are the focus of current wear component development and prototyping.
To date, that field trial has been in operation for over 12,000 hrs. The data generated from the trial is being applied to Metso’s empirical hydrocyclone model used for sizing and simulation purposes. It has confirmed the MHC Series achieves the performance for industry leading hydrocyclone technology. The field trial also confirmed that the MHC performance is predictable and responds as expected due to changes in operating conditions. Testing in the field and on the pilot scale is an ongoing process as the Metso MHC product line continues to develop.
Conclusion: Significant advantages over previously available technologies
Based on the test program, the MHC Series performance is proving to be industry leading with an increased flow rate for a given pressure drop. Wear components within the individual units are optimized to promote even wear life throughout the entire assembly, resulting in increased overall wear life and consistent performance throughout the hydrocyclone lifecycle. These advancements have great potential to deliver long term benefits in improving classification efficiency while considering capital costs and operating costs.
Global Product Manager, Hydrocyclones