Brazil’s iron ore major Vale continues to make progress with its autonomous mining journey. Looking at blasthole drilling, some are already running fully autonomous while a number of other drills are currently operated in assisted mode, as part of the commissioning phase. Carajas has three autonomous drills in operation and seven more will be operational by the end of the year. Throughout Vale the company is expanding from 11 to 21 autonomous drills in 2021 across Carajas, Brucutu and Itabira. Another ongoing project is to automate stockyard machines, which has already been completed in Malaysia and is being implemented in four Brazilian states.
In drilling the main focus has so far been on retrofitting existing drills at Carajas and Itabira with FLANDERS ARDVARC automation technology including Epiroc DML and Pit Viper units plus Caterpillar MD6420 machines. Semi autonomous Cat MD6310 drills with OMA (Operator Mission Assist) have also been deployed at S11D working with Cat dealer Sotreq.
As for autonomous haul trucks, 13 of them (Cat 793F CMD) have been operating in Brucutu mine since 2018 while a second fleet (which will eventually total 37 Komatsu 930E-AT) is being tested in Carajás. Ten of these trucks are now operational in Carajás.
The Brucutu fleet recently passed a major milestone, completing in June 2021 100 Mt of material moved at the Brucutu mine. Since the beginning of the project’s implementation in 2016, there have been no accidents caused by autonomous trucks, carbon emissions have been reduced due to lower fuel consumption and the mine’s productivity has increased. With a capacity to transport 240 t, the trucks are controlled by computer systems, GPS, radar and artificial intelligence, covering the route between the mining front and the unloading area. The result of six years of research and testing, autonomous vehicles began to be used in 2016 in test mode. In 2019, all 13 trucks circulating in Brucutu were already using the new technology, making it the first mine in Brazil with 100% autonomous operation. The trucks have already covered 1.8 million kilometres.
Over the last five years, it has been proven that the fuel consumption of autonomous trucks is 11% lower than that of crewed trucks, resulting in a reduction of 4,300 t of CO2 per year in the atmosphere. The maximum speed of the trucks, which was 40 km/h, reached 60 km/h. Hourly productivity, measured by the amount of iron ore transported per hour, increased by 11% – five percentage points more than expected. The autonomous operation also favours the maintenance of equipment. Tyres, for example, had a 35% increase in their useful life – ten percentage points more than expected. In addition to saving the company, this number generates less waste disposal.
Operators who used to stay in the cabin received training and were relocated to other functions, one of them being the operation in the control rooms – with air conditioning, without vibration and noise – many kilometers away from the mining front. With this, risk situations involving truck operators, such as tipping and collision, were eliminated.
“There are many results and lessons learned to be celebrated with the current level of maturity of the autonomous mine,” explains the Executive Manager of the Brucutu and Água Limpa Complex, Jefferson Corraide. “Certainly the most important advance provided by the implementation is the reduction of people’s exposure to risk. The mine was made safer both by the embedded technology and by the discipline required to make the process sustainable and fluid. The autonomous operation optimisation processes go beyond the truck and encompass the complex as a whole.”
The Operation and Infrastructure Manager in Brucutu, Kléber Gonçalves, explains that within the mining area, manned and autonomous vehicles are in constant interaction and, in order for it to be safe, all vehicles are adapted. This allows autonomous trucks to plot their routes and, preventively, reduce speed or even interrupt their route, avoiding accidents. “The equipment also has sensors that continuously map and identify the terrain, objects and people, so that the autonomous technology can paralyze the operation of one or more trucks in case of changes that were not foreseen in the path determined by the centre control,” he says.
People continue to play an important role in the autonomous operation. The teams that oversee the entire process can be comfortably installed miles away from the vehicles. Equipment operators from Brucutu were transferred to other functions at the mine itself or at other Vale units in the region. Part of the team was used in the management and control of autonomous equipment, after having gone through training courses. The trend, with the greater use of autonomous technology, is for Vale to create more opportunities for highly qualified professionals in the technical and engineering areas of automation, robotics and technology within the operation.