EXPLOSIVES & BLASTING
quarrying applications across five continents were factored into this study , together with theoretical analysis and laboratories tests run in USA and Spain , according to MAXAM .
The study compared the performance of RIOFLEX with that of standard bulk emulsion explosives documented by MAXAM and authors in peer-reviewed literature during the last 35 years . The studies carried out in mines and quarries in Africa , Australia , Europe and South America , and in laboratory scale evidence , repeated the advantages of RIOFLEX technology , the company said .
The theoretical characterisation of RIOFLEX and emulsion in different densities and nonideal conditions – from its ideal thermodynamic characteristic to its non-ideal performance – demonstrated that RIOFLEX-based formulations have more energy to break and move rock than formulations based on emulsions , MAXAM said .
“ The energy of non-ideal ammonium nitratebased explosive depends on the water content of that explosive ,” it explained . “ While RIOFLEX usually has less than 13 % of water , some commercial emulsions can have up to 23 % water . The amount of water negatively affects the total energy of the explosive .”
Underwater energy tests and confined velocity of detonation ( VOD ) measurements carried out highlighted that , under identical conditions , 100 % RIOFLEX has a higher VOD than 100 % standard emulsion . On average , the VOD of RIOFLEX was found to be 15 % higher than that of standard emulsions , MAXAM said .
More than 30 full-scale production blasts were carried out in three different mine operations to evaluate the outcomes of RIOFLEX versus different emulsion products regarding rock fragmentation , environmental effects and downstream impacts . All these blasts were carried out under similar rock and ground conditions , according to MAXAM .
The main results and conclusions obtained from the analysis were summarised as follows : n Rock blasted with RIOFLEX had a smaller size than rock blasted with standard bulk emulsion as measured by the X80 fraction . The reduction ranged from 15-38 %; n Using RIOFLEX also allowed a powder factor reduction of 10-18 %, depending on the baseline , without compromising rock fragmentation and digging rates ; n Better fragmentation facilitated 11-18 % faster digging rates and lowered truck cycle times . One study found that truck cycle times dropped by 8 %; and n In ore milling , significant improvements of up to 13 % in throughput rates and energy consumption were observed . The study also demonstrated the theoretical models of the blasting results only predict a fraction of the actual observed benefits of RIOFLEX , MAXAM said .
“ Real overperformance of RIOFLEX goes beyond the theoretical difference in energy ,” it said . “ This unique feature relies on the different nature of RIOFLEX when compared to other products , due to the higher density of the matrix and mechanical sensitisation and cross-linking technology .”
An autonomous future
Reviewing the past , present and future of blasting technologies at the MassMin 2020 conference , Danko Morales , Enaex Manager of Underground Mining , covered a lot of ground – from the transition to mechanised charging using pumpable emulsions , to alternative preconditioning solutions for dynamic weakening with explosives , to the ongoing shift towards emulsions or other water-based explosives in the blasting process .
Morales stated : “ In the near future … all operations will be mechanised , and explosives will become completely on-site manufactured . After the massive application of water-based explosives , the industry ’ s next step will be the full automation of the rock blasting sequence , including priming , manufacturing , charging and initiation .”
In 2019 , simulation studies were carried out to evaluate the potential performance of an autonomous charging process in an important block caving mine in central Chile , Enaex said .
With the incorporation of autonomous equipment and emulsion , the exposure for personnel could be reduced from more than 25,000 hours to zero , with six additional effective hours potentially added to available daily working time , according to the company . Given the number of metres to develop , autonomous charging would allow preparation time to be reduced from 90 to 82 months ( 10 % less ), and , without interference , it could be achieved in just 41 months ( 55 % less ).
Beyond the use of autonomous activities and emulsions , further developments in robotics are projected in underground mines in the short term . These advances will transform many highrisk human activities into more secure , remote , autonomous and robotised tasks , Enaex said .
While this is yet to be realised underground , Enaex is closing in on this achievement in openpit mining .
Robotic solutions , which include RoboMiner ® , Mine-iTruck ® and Stemming-iTruck ® , can form a complete family of equipment for performing full remote blasting in open-pit mines , it claimed .
RoboMiner is a humanoid unit mounted on four wheels that can moor and prime the blastholes ; Mine-iTruck is a “ sophisticated ” truck to transport raw materials , manufacture
explosives on-site and load them ; and the Stemming-iTruck can plug the blastholes with gravel .
“ Mine-iTruck was first used in 2018 for the first tele-operated charging of ANFO in the world , carried out in a large Chilean open-pit mine ,” Morales said . “ Mine-iTruck , together with Stemming-iTruck and RoboMiner , were used for the first full remote blasting in mining history . Today , this package that includes the full set of robotic solutions is the only one of its kind in the market , and it is being successfully implemented in an important operation in northern Chile .”
He added : “ From the point of view of open-pit mines , tele-operated , robotic and autonomous activities will increasingly define the future . Teleoperation and robotics are technologies already in use by Enaex and they have helped gain access to places that are difficult and / or dangerous to reach . Since 2019 , Enaex has demonstrated that complete tele-operated and robotised blasting is possible in open-pit mines using RoboMiner , Mine-iTruck and StemmingiTruck . The next step will be to automate all activities .”
Today , Enaex units can drive autonomously thanks to Mobius ® software , which is part of the partnership between Enaex and Automated Solutions Inc , but there are special tasks still requiring remote control .
As in underground mines , Enaex seeks to go further in open-pit mining to achieve fully automated blasting in the short term .
On the digitalisation front , Morales highlighted Enaex Bright ® as one of the company ’ s key projects . This digital platform can provide recommendations on blasting agent types , optimal mixtures and quantities based on data analysis , machine learning and artificial intelligence .
He explained : “ Today , Enaex Bright is working on step one . It is collecting information from manufacturing trucks , saving design data like blasting geometry and rock type , and also saving operational parameters such as quantities of explosive and depth of the drill holes .”
The digital network
Becker Mining Systems ’ newest product in its line of networking solutions , smartblast ® LTE , is designed specifically to help a remote firing system work in conjunction with mine LTE communication systems .
Just one of the benefits that comes with applying smartblast LTE units in a drill and blast setting is the reduction in misfires due to the minimal infrastructure requirements and easeof-use that come with applying smartblast LTE , the company claimed .
100 International Mining | AUGUST 2021