We carry out continuous environmental work where we set specific targets for the more efficient use of resources and reduced impact on the environment.
We establish an environmental management program every year. The general purpose of the program is to create a plan and targets to work actively to reduce the company’s environmental impact. The program highlights and values facts about and around all environmental aspects in order to identify the factors that have the greatest impact on the environment. The result of this work is then used as a basis when we adopt the environmental objectives for the following year.
Large aspects of our continuous efforts are focused on reducing energy consumption (measured in energy per produced tonne), reducing the amount of waste that goes to landfills and incineration, and how we use raw materials as optimally as possible.
Besides working with, for example, improving energy performance in general in the processes, we regularly investigate opportunities to use alternatives and/or supplementary fuels to our existing fuels.
Our continuous efforts to achieve lower energy consumption per tonne of produced aluminium are enabling a more resource-efficient production process and thus creating even more environmental benefits. They are also leading to increased profitability due to lower energy costs per tonne. We currently use LPG as the sole source of energy for the smelting and alloying furnaces, and all work vehicles are powered by electricity or environmental diesel. When we replace work vehicles, as far as possible, we always aim to replace them with non-diesel powered vehicles.
We work continuously with the waste generated by our operations. We strive to reduce the volume of waste and residual aluminium content and return elements to our processes. As an aspect of this work, we started to recycle aluminium from salt slag. This is accomplished by a slag cooling facility that utilizes rapid cooling to separate the metal content. The metal content are sorted by machine. Non-aluminium materials go to recycling while the aluminium is returned to the smelting process. The slag cooling facility was put into service in 2016 and employs a new, innovative technique.
Salt is added during the smelting process, which increases metal yield during smelting and leads to more efficient use of our resources, raw materials and energy. During 2016, we initiated a collaboration with a new recipient of salt slag, which cleans the salt slag and returns the salt to the plant so that it can be reused in the smelting process. This recycling contributes to the lower environmental impact. Previously, only potassium was extracted from the salt slag, and the rest was deposited in landfills.
Flue gases are formed in the process and are purified in an advanced flue gas unit.
As an example, the addition of salt and chlorine in the smelting process generates hydrogen chloride emissions. By adding bicarbonate in flue gas purification, the hydrogen chloride is absorbed in the filter. The flue gases that have passed through the filter also include other substances regulated by emissions regulations associated with the environmental permit. Stena Aluminium measures and checks all the substances in accordance with the emission regulations and inspection programs.
Minimizing noise from all parts of the plant is an important focus area for both the plant surroundings and the working environment.
Handling of raw materials often produces noise in some form and is a highly prioritized area. A strategic decision was consequently made in 2016 to construct material handling structures to enable raw materials to be handled in a more isolated fashion. This investment will create many benefits for both operations and the neighboring area, in among other ways, by minimizing noise and making raw material handling more efficient.
The first phase of construction was completed in June 2017.