One of the main contributors to GHG (Greenhouse Gas) emissions in mining is diesel. We are looking for transformational, economically viable technologies (or with medium-term prospects) that allow partial or total substitution of diesel by biogenic fuels without complex modifications for their use.

The proposed solutions should maintain or enable an improvement in vehicle performance and, in the case of partial substitution, be miscible with fossil diesel or not require complex modifications to the vehicles. Additionally, they should not compromise vehicle operability or increase stops and maintenance intervals. Solutions focused on underground mining vehicles should consider the specific industrial environment with moisture, vibration, dust, and limitations in data transmission. Moreover, should be observed the existing legislation for testing new fuels and the requirements for using fuels in underground mining. 

The evaluation indicators in this case are specific fuel consumption and GHG emissions reduction. For solutions involving liquid fuels, quality indicators should be like fossil diesel. We are not looking for solutions that pose contamination risks to internal combustion components or solutions that overload or increase the pressure drop in diesel oil filters.

Our mining units process the ore into zinc, copper, and lead concentrates. To obtain the concentrate it is necessary to process the ROM (run of mine), which is the ore before beneficiation, through several stages, including particle comminution, concentration, and finally thickening and filtration.

During these processes, water use is essential and must be treated subsequently. However, we face difficulties reusing the generated effluent due to the characteristics of the beneficiated material originating from volcanic massive sulfide, deposits with recurring carbonates, and quartz.

The generated effluent contains various metals in solution that must be reduced before disposal. In this challenge, we are looking for solutions that treat the effluent to promote water recirculation, reducing water intake and maintaining the parameters established by the regulations (reference standard: CONAMA Resolution No. 357/2005).

At Nexa, we are committed to safety in our operations. Consequently, we are constantly looking for more efficient ways to monitor and track the conditions of all our industrial processes. 

Currently, we have a level-by-level access control system in the mine through the leaky feeder network, where we transmit 120 kbps in a 20 kHz channel. 

We are looking for solutions that can use this data transmission infrastructure. The bandwidth is limited, and communication applications should consider this restriction. We want to add value and create other opportunities, such as monitoring geotechnical parameters, air quality (in all its parameters), temperature, noise, etc.

The solution should impact safety or productivity (e.g., optimizing the execution of preventive actions, reviewing ventilation systems, mine planning, team allocation, etc.). If the measured parameter is regulated, the solution must at least meet the standard criteria, with the potential to be accepted in an eventual inspection.

Geomechanical stability in underground mining is fundamental to ensuring safety and the continuity of operations. This stability is ensured through measurements of seismic activity, fracture position, rock quality and strength, and rock mass stresses, among other parameters. Measurements are made regularly, but there are opportunities to improve their precision and data granularity.

The challenge, therefore, is to capture geomechanical information and ensure the availability and accessibility of this information for decision-making. Due to difficult access and limited connectivity, solutions that are portable, widely deployed, fast and locally processed, ergonomic, continuous, low-cost, and reliable are desired. 

The project aims to allow the prediction of potential incidents, reduce the occurrence of unforeseen events, and increase the efficiency of our operations.