NORDIC SUPPLIERS
The “ trick ” with both systems is that , as the system is continuously analysing , it does not matter how much cuttings are being conveyed on the belt towards the XRF unit . With dense online analysis from the holes , it is still possible to calculate an accurate 3D grade control map of the blast bench , according to the company .
When integrated with GPS systems on new drills , the drill hole , sample and rig can all be tracked back to an exact location , according to Auranen . This is especially important for mines monitored from remote operations centre .
Automating the sampling and analysis process allows miners , at the most basic level , to know where the ore and waste is coming from within the drill hole itself . Companies are then free to use this data as they see fit .
One option is to , post-blast , accurately assign the waste and ore piles to the loading and haulage team . Another option is to adjust the amount of explosives inside the hole based on the location of the ore and waste – more explosives for the ore and less for the waste in the majority of operations . A third is to use timed blasting to ensure the waste rock and ore fly in different directions for definitive separation .
More uses of this data are bound to arise when the first use cases are established , which Auranen is hopeful are not too far away .
“ We have tested the system in large rotary rigs and down-the-hole rigs in real world mines ,” he said . “ This has seen it operate in conditions from -30 ° C to + 54 ° C .
“ With a commercial product now established and discussions with miners ongoing , we could install a system in six months from an order .”
Auranen was happy to provide an update on its XRF ore sorting efforts when in conversation with IM too .
Referencing its latest pilot project in open pit and underground mines with its IMA XRF-Bucket Scanner – which sees a sensor solution positioned at a specific location where LHDs and wheel loaders can check the grades of their bucket loads by positioning said bucket underneath the sensor – Auranen said the company is now incorporating RFID tags into the equation to achieve close to real-time ore tracking .
“ We have a system where we put RFID marker tags in the ore to understand where that ore originally came from – from the blast hole in the mining bench or the stope – then we use tag readers to read the tags travelling with the ore , first , on the conveyor belt using an IMA XRF analyser after primary crushing to connect the analysis results with the tag and , second , at the destination on the concentrator feed belt ,” he said .
The first benefit is immediate feedback to mining operators of the ore grade . This data is combined with the concentrator results and reconciled with the mine ’ s block model to , Auranen says , increase the efficiency of mining , reduce waste rock dilution and ore losses , and act as a quality control and quality assurance ( QA / QC ) tool between the mine and concentrator .
“ In these trials , we have noticed that some 10- 15 % of mill feed going to the concentrator is below the cut-off grade ,” he said . “ Of course , this is not zero grade material , but the financial impact is very big . We are talking about $ 40-50 million a year with some of the larger mines .”
There is an argument for using the IMA sensors with IMA BOSS bulk ore sorting systems and an RFID tagging system for separating clean waste from acid forming waste when placed in waste piles , potentially tracking future revenue sources ( dependent on commodity prices and technology ) and eradicating the risks associated with acid rock drainage , Auranen added .
Wireless blasting
IMA has previously carried out an ore sorting report for Outokumpu ’ s Kemi chromite mine , in Finland , as part of an Oulu Mining Schoolbacked study , and this underground mine continues to act as a testbed for new innovations .
One such innovation is wireless blasting where the mine , together with blasting and explosives specialist Forcit , recently introduced centralised wireless blasting via Wi-Fi using Davey Bickford Enaex technology . Forcit , with its partner Davey Bickford Enaex and Kemi Mine , co-operated to implement the DaveyTronic ® UG system to ensure safe and economical blasting at the underground operation , it said .
The centralised blasting system enables controlled implementation of blasts using the Wi-Fi network of the mine . No personnel need to be present in the mine during the blast because
Forcit , with its partner Davey Bickford Enaex and Kemi Mine , co-operated to implement the DaveyTronic ® UG system to ensure safe and economical blasting at the chromite operation
all fields in one blasting window are fired from a centralised blasting place in a controlled manner .
The system also enables the ignition of fields using non-electronic detonators and fields using electronic detonators in the same blasting window . Non-electronic detonator fields are ignited using an electronic detonator via the DaveyTronicUG system .
“ DaveyTronicUG enables two-way communication with all blasting fields up to the moment they are blasted , which increases quality and safety ,” Forcit said . “ It is possible to implement the whole procedure with just a push of a button , in which case all fields are verified and charged to be ready for a blast . The actual blast can be done automatically , field by field , at pre-agreed intervals or , if wanted , manually , field by field .”
Arto Palokangas , Production Engineer at Kemi mine , says the new system will first and foremost increase safety .
“ To carry out the blasts in one blasting window nowadays several groups of blasters have to move to several locations in the mine in a pre-agreed order in a short window of time ,” he said . “ With the DaveyTronicUG system , blasting can be carried out centrally from a single location when the mine is empty . In the future , centralised blasting will also enable the shortening of the blasting window and , this way , increase the efficiency of working time .”
The commissioning of the system and training of the staff were implemented towards the end of 2020 . The training covered several topics : the commissioning of the devices , attaching the devices to the mine ’ s Wi-Fi network and training blasters to use the system .
At the beginning of 2021 , the system has
46 International Mining | MAY 2021