WORLD PROSPECTS
Leveraging clean diesel engines in underground mines
Limiting emissions to mitigate
environmental impact and comply with regulations is key to most mining operations and paramount for underground mines . Ventilating deep mines is both challenging and costly , but it is necessary to ensure people can work safely and comfortably – and to keep air temperatures suitable for equipment operation .
“ We know carbon reduction , air quality and safety are huge issues for our customers , and we are always looking for ways to help them meet those challenges ,” Paul Bitter , Product Manager for Cat hard rock vehicles , says .
Caterpillar offers several solutions to reduce diesel engine emissions , including retrofittable filtration options and engines meeting the strictest emission standards . “ One of the most effective solutions we offer for lowering emissions is EU Stage V compliant engines in our machines ,” Bitter says .
Stage V emissions packages are available for several Cat underground hard rock loading and hauling machines , including the R1700 and R2900 LHDs and the AD45 and AD63 trucks . The AD45 emissions package is also available as a retrofit for the older AD45B , Cat says .
The R1700 underground loader was Caterpillar ’ s first machine equipped with an EU Stage V engine . According to Bitter , the R1700 was redesigned in 2018 with a focus on reducing emissions , improving fuel efficiency , upgrading hydraulic performance and increasing machine capacity .
“ Our emissions controls start inside the engine – where air management , high-pressure fuel injection particle size , pre-ignition injections and our NOx reduction system play a part in reducing emissions ,” he says . Complementing these engine controls is the Cat Clean Emissions Module ( CEM ), an aftertreatment solution that includes a diesel
oxidation catalyst and a diesel particulate filter ( DPF ). The CEM system also uses diesel exhaust fluid ( DEF ) to further reduce NOx emissions . Cat engines with aftertreatment have operated nearly 170 million hours in the field , according to the company .
The R2900 uses the same system design as the R1700 , but it required some upscaling to work with the larger engine . “ To accommodate the aftertreatment package , we adopted an upsized , modular R1700 engine-end frame design to accommodate the Stage V engine ” Bitter said . “ The R2900 represents a very important size class in Europe , so it was critical that we bring this machine up to Stage V compliance early .”
Caterpillar also offers EU Stage V engines for two underground trucks , the first of which was the new AD45 . “ In developing our new AD45 , we also found a way to retrofit the engine and aftertreatment solution to the AD45B ,” Bitter said . “ This represents a substantial benefit for
Cat AD63 underground truck with particulate filter above front tyre
our customers running this earlier-generation truck .”.
For one mine in Western Australia , retrofitting its existing fleet with emission controls saved millions of dollars and is enabling its existing fleet to complete its lifecycle , according to Cat .
“ One of the best opportunities for upgrading emission controls is during a machine rebuild ,” Bitter says . “ Cat machines are built to be rebuilt , and there ’ s no better time to upgrade the machine than when it ’ s already scheduled for downtime .”
Caterpillar ’ s largest and newest underground truck , the 63-t-payload AD63 ( pictured ), also offers a Stage V solution . Its Cat C27 engine , which produces 588 kw of power and is approved by CANMET for use in underground mines , makes use of the same engine controls and NOx reduction system found in the smaller LHD engines . Additional design work was done to meet Stage V standards without the use of a DPF or DEF .
Cat diesel exhaust aftertreatment system
Filters reduce particulates
In addition to EU Stage V solutions , Caterpillar offers a diesel particulate matter reduction solution called the Wall Flow Filter . This filter captures particulate matter and reduces it to below US EPA Tier 4 Final levels – greater than a 98 % reduction – without any impact on machine performance , according to the company .
Wall Flow Filters are available as retrofit kits and are integrated with each machine ’ s health monitoring system . The filters can operate for as long as 3,000 hours between cleanings under normal operating conditions , while service life is 10,000 hours . www . mining . cat . com
6 International Mining | OCTOBER 2020