Ore is trucked from the open mine pit to the processing plant where it goes through three stages of crushing and screening, pre-concentration via heavy media separation followed by flotation, oxidative leaching and dewatering.
During crushing operations the ore is crushed down to rock sizes of 9 mm through three stages of crushing, commencing with a jaw crusher, followed by secondary and tertiary crushing using cone crushers. After crushing, low grade ore moves through to the Heavy Medium Plant to upgrade the ore to the target process feed grades while high grade ore moves directly through to the primary grinding stage.
Crushing operation equipment generates large amounts of dust and results in a hazardous working environment. Controlling dust within crushing operations is critical to keep equipment working effectively and protect the health and safety of workers.
As part of Stage 3 of the MRM site expansion works, a tender was issued for a dust extraction system to manage dust created by two secondary and tertiary cone crushers and three screening plants.
Grydale were awarded the contract to design, manufacture and install a Grydale JMS F-Series dust extraction system. This unit provided 38,000m3/hr of air flow at -2.0kPA, which offered the capacity to extract dust from the two secondary and tertiary cone crushers and three screening plants. The customised unit consisted of a centrifugal fan, filter house, hopper assembly, support legs, rotary valve discharge and maintenance platform.
The duct run was designed to collect dust from key points of processing works and fed into a common duct run back to the JMS F-Series dust extraction system.
An air flow meter on the dust extractor turns up the Variable Speed Drive (VSD) when additional air volume is required. Equally the air flow meter will turn down the VSD so the dust extractor uses less kW for the same amount of volume depending on the temperature and conditions. This results in significant power savings.
The JMS F-Series dust extractor has a filtration efficiency of 99.99% at 0.067microns and air is exhausted via the clean air stack. Dust (primarily lead concentrate) is discharged using stainless-steel rotary valves onto a conveyor and back into production for the next stage of processing.
The dust extraction system not only minimises health, safety and environmental risks but also ensures that operational efficiency is maintained by recovering product.
Grydale certified technical installation team were responsible for installing ducting and the JMS F-Series dust extraction system and associated ducting onsite. Working with the onsite project team and external contractors installation was completed within a short site shut down window and commissioned onsite.