Decarbonization approaches in mining and metal production

The metal and mining industries contribute to roughly 8% of the global carbon footprint. The steel industry, in particular, produces enormous quantities of CO₂, because up to 70% of coal and coke are burned to produce steel in blast furnaces₁. 1.85 tons of carbon dioxide are currently created per ton of steel produced₂. Using alternative fuels in mining and steelworks is one way to lower the emissions. How this works, and which sensors from SICK help with this process, is described in the following article.

Welcome to part five of our series on decarbonization where we focus on mining and metal production.

Decarbonization of the mining industry on the path to a sustainable future

To ensure a more environmentally friendly and sustainable extraction and processing of raw materials, mining companies are taking significant steps to reduce their environmental impact.

The most important strategies include:

• Improving the energy efficiency
• Electrifying the vehicles and machines
• Using alternative fuels
• Optimizing processes
• Using automation solutions
• Integrating themselves into the upstream and downstream supply chain

Mining companies are pursuing a holistic approach and implementing measures to reduce emissions in every phase of their business. This includes direct emissions from their mining operations, indirect emissions from purchased energy, and emissions along the entire value chain.

Mining 4.0 plays an important role in this context, whereby 75% of companies will have retrofitted their important machines and vehicles with intelligent sensors by 2027. The digital transformation in the mining sector means more safety, higher productivity, more efficiency and profitability, as well as a more sustainable operation.

Improving the energy efficiency

Energy efficiency is one of the most important drivers for decarbonization. Investment in advanced technologies and better methods for minimizing energy consumption and reducing greenhouse gas emissions are essential. By optimizing processes and using more energy efficient equipment such as high efficiency motors, batteries and intelligent control systems, companies are achieving significant energy savings and reducing their carbon footprint.

In large mines, for example, it is particularly important to pinpoint the exact position of individual vehicles and tools. Ultra-wideband tags in combination with a TDC (Telematic Data Collector) gateway system offer an ideal solution for localizing equipment in extensive mining facilities. The system sends the space-time coordinates to a central database and transmits the monitoring data in real time, regardless of whether the equipment is located above or below ground.

Dump trucks are used in surface mining for transporting large volumes of overburden, coal or ore. The volume on the load bed needs to be maximized without overloading the vehicle. The load bed is also monitored to ensure it has been fully emptied before the truck is reloaded. Using LiDAR technology, the volume of the load is measured directly. A load volume measurement system mounted above the vehicle scans the loaded bed and determines the volume based on the time-of-flight principle without requiring the dump truck to stop. The time difference between the emission and receipt of a signal by the LiDAR sensor provides the necessary information for the volume measurement. LiDAR sensors from SICK are rugged, reliable and accurate and therefore ideally suited for the harsh conditions in mining.

Electrification and alternative fuels

Electrification is a transformative trend in the mining industry. By replacing diesel-operated machines with electric alternatives, companies can significantly reduce their emissions. Furthermore, the use of alternative fuels such as natural gas and renewable energy sources is also gaining in importance. These clean fuels contribute to lowering carbon emissions and, at the same time, ensuring a reliable energy supply for mining. Automation also plays an important role in this transition.

Process optimization for greater efficiency

Process efficiency plays a decisive role in reducing emissions. Mining companies are continuously improving their operations by introducing innovative technologies and methods. Advanced automation solutions, including sensors and systems for predictive maintenance, devices for monitoring dust, and device status monitoring enable problems to be detected early, downtimes to be reduced, and the overall efficiency to be improved. These technologies improve productivity while at the same time minimizing energy waste and emissions.

For security and productivity reasons, mining companies want to be able to localize their vehicles within the mining area. To this end, a rugged RFU630 RFID reader on the roof of mining vehicles continuously searches the surroundings for tags. These are installed throughout the entire mine site. When a vehicle drives past a tag, the sensor records the exact position data of the vehicle.

The MINESIC700 GHG continuously records GHG emissions from underground coal mines using the S715 extractive gas analyzer and the FLOWSIC100 flow measurement technology. High-precision sensors also measure temperature and pressure. Humidity measurement can also be integrated as an option. Customized reporting software can be used to create emission reports that are approved for submission to the tax authorities.

LD-MRS and LMS LiDAR sensors are important prerequisites for autonomous transport vehicles. The MAX® position sensor allows real-time condition monitoring and predictive maintenance for the hydraulic cylinders of mining machines. It can withstand high mechanical loads such as shock and vibration.

Integration into the upstream and downstream supply chain: steel production

More and more mining companies are collaborating with downstream and upstream partners to create a more sustainable and better networked supply chains. We will now consider the steel industry more closely.

Steel is the most versatile industrial material in the world. It therefore plays an important role in society. The energy transition projects, and the infrastructure needed to produce steel, require thousands of tons of industrial raw materials, so the demand for steel continues to increase. Efficient steel recycling and decarbonization are therefore essential.

The production process of high quality iron ore pellets, for example, has proven to be an environmentally friendly solution. These pellets provide a superior alternative for the direct reduction of iron (DRI) process by reducing emissions and increasing the efficiency of steel production. Furthermore, by replacing the sinter material in traditional steel production with lump ore or pellets, the emissions and waste generation can be substantially reduced.

The switch from coke and coal burned in blast furnaces to the direct reduction process (Direct Reduced Iron, “DRI”) using hydrogen as the reduction agent is the biggest trend when it comes to plans to decarbonize iron and steelmaking. The huge quantities of hydrogen required are produced by electrolysis. The electricity required for this is ideally supplied from renewable energy sources.

The sensors from SICK support iron and steel producers in optimizing their processes, with safety aspects in production, and in meeting emission requirements.

Example 1: Monitoring of process gases in direct reduction plants

In direct reduction plants, it is necessary to reduce the oxygen in shaft furnaces. A preheated reduction gas mixture is therefore introduced into the furnaces. A combination of different extractive gas analyzers with ATEX certifications simultaneously measure all gas components relevant to this process. The analyzers with hot/wet extractive measurement technology detect up to six components – including those such as H₂O that condense at low temperatures. The analyzers with cold/dry extractive measurement technology, however, are connected to different sensors to measure, among other things, H₂, CO and CO₂. The gas analyzers also check the quality of the various process gas streams in the shaft furnaces. The devices also check the ratio of hydrogen to carbon monoxide in the finished syngas mixture. SICK offers several variants of the analyzers to suit the different explosion protection requirements of the ATEX Directive. This enables numerous applications in many different sectors to be catered for.

Example 2: Gas flow measurement in direction reduction plants

A direct reduction plant is filled with iron ore pellets. Reduction gas with a high concentration of carbon monoxide and hydrogen simultaneously fed into the plant removes oxygen atoms from the iron ore. This creates solid iron sponge. Thanks to their ultrasonic technology, the rugged FLOWSIC100 Flare-XT gas flow measuring instruments precisely and reliably measure the speed, volume and flow of the contaminated, humid and explosive gas mixtures. Throttle valves allow the device to be cleaned and serviced without interrupting the gas flow. The intelligent device monitoring of the FLOWSIC100 Flare-XT also enables predictive maintenance. This improves plant availability.

Sources

₁ https://www.futurecoal.org/coal-facts/

₂ https://www.carbonclean.com/blog/steel-co2-emissions

Read the other parts of our series on decarbonization

Read more in part one of our series on decarbonization

Read more in part two of our series on decarbonization

Read more in part three of our series on decarbonization

Read more in part four of our series on decarbonization