CO2 emissions and recycling
The production of different metals and alloys from primary raw materials generates different amounts of carbon dioxide (CO2) depending on the technology used, the energy source and other factors.
Below are estimates of CO2 emissions for the production of selected metals:
- Aluminium: The production of aluminium using the electrolytic method (Hall-Héroult method) is very energy-intensive and can generate between 9 and 12 tonnes of CO2 per tonne of aluminium produced.
- Copper: CO2 emissions in copper production depend on the extraction method. For the traditional smelting method (e.g. the copper-sulphate process), emissions can range from 2 to 3.5 tonnes of CO2 per tonne of copper. In contrast, for modern technologies such as hydrometallurgy, emissions can be lower, ranging from 0.5 to 2 tonnes of CO2 per tonne of copper.
- Lead: Lead production from an ore deposit generates between 1.5 and 2.5 tonnes of CO2 per tonne of lead.
- Zinc: CO2 emissions in zinc production can range from 1.2 to 2.5 tonnes of CO2 per tonne of zinc, depending on the process used.
- Tin: Information on CO2 emissions in tin production is limited, but it is estimated that the CO2 emissions in the production of 1 tonne of tin are between 0.5 and 1.5 tonnes.
- Steel: Steel production is a complex process that involves various steps and technologies. CO2 emissions in production range from 1.8 to 2.3 tonnes of CO2 per tonne of steel. However, the use of modern technologies, such as steel production using hydrogen as a reducing agent, can significantly reduce CO2 emissions.
- Nickel: CO2 emissions in nickel production using traditional processes, such as the Caron process, are around 15-35 tonnes of CO2 per tonne of nickel produced. However, there are also modern technologies, such as hydrometallurgy, that can reduce CO2 emissions.
It is worth noting that the above values are estimates and may vary depending on the specific production conditions and technologies used at individual plants. CO2 emissions can also be reduced by using low-carbon technologies, increasing energy efficiency and using renewable energy sources.
Recycling of non-ferrous metals
Recycling of non-ferrous metal scrap contributes to a significant reduction in CO2 emissions compared to the production of metals from virgin raw materials. The exact CO2 reduction figures depend on a number of factors, such as the type of metal, the recycling process and the composition of the raw material.
Below, data showing energy savings, CO2 reductions in scrap recycling:
- Aluminium recycling: The production of aluminium from secondary aluminium can result in energy savings of up to 95% compared to production from bauxite ore. As a result, the CO2 emissions associated with aluminium recycling are significantly lower.
- Copper recycling: Copper recycling can result in energy savings of approximately 85-90% compared to production from copper ore. This energy saving contributes to a reduction in CO2 emissions.
- Lead recycling: Recycling lead can result in significant energy savings. It is estimated that recycled lead production can save between 60% and as much as 75% of energy compared to lead production from lead ore.
- Zinc recycling: Zinc recycling can result in energy savings of approximately 60-75% compared to production from zinc ore. This leads to a significant reduction in CO2 emissions.
- Tin recycling: Recycling tin contributes to energy savings, although not as significant as for other metals. It is estimated that tin recycling can save between 5% and 10% of energy compared to producing tin from tin ore. Nevertheless, any energy savings are important for sustainability.
- Steel recycling: Recycling steel is significantly energy efficient. Producing recycled steel can save between 50% and as much as 75% of energy compared to producing steel from iron ore.
- Nickel recycling: Recycling nickel also has energy benefits. It is estimated that nickel recycling can save between 40% and 75% of energy compared to producing nickel from ore. The energy savings depend on the specific recycling process and the quality of the nickel scrap used.
It is also important to note that the recycling of scrap non-ferrous metals contributes to the saving of natural resources, the reduction of water consumption and the reduction of other negative environmental impacts, such as soil and groundwater pollution.
With the above in mind, it seems that the following slogans are not just words but real support for a green revolution in the world:
"Your action, our future - collect scrap metal!"
"Your small steps, big benefits - collect scrap metal and reduce CO2 emissions!"
"Collect scrap metal, save resources, protect our heritage!"
"Your scrap, your contribution - collect and be part of the green revolution!"
Elaboration: Rafał Matyasik