PAH free products
By developing products that do not contain PAHs, Elkem Carbon aims to minimise PAH emissions both from its own production and from its customers’ production. Elkem Carbon has developed ELSEAL® Type G as an alternative to coal tar pitch based ramming paste. ELSEAL® Type G contains neither PAHs nor other hazardous substances. There are no emissions of PAHs during use, and workers will not be exposed to these potentially harmful compounds.
To avoid unnecessary disposal of waste containing PAHs, scrap production is recycled in the production of new products. The rejected products are crushed, sieved and fed in controlled quantities into the production process through a separate silo.
Reduction of PAH emissions to air
Elkem Carbon Fiskaa, Norway, aims to keep its emissions of PAH under 50 per cent of what is permitted in their environmental permit, even with increased production. A stable production process in a well-maintained facility is important to reach this goal. PAH emissions to air from the plant and in the working environment have been greatly reduced, and the positive trend has continued in 2015. Systematic work to reduce dust has had a strong impact on Elkem Carbon’s PAH emissions to air. As part of the program Elkem Carbon has done a comprehensive mapping of exposure to dust and PAH for all employees. The vast improvements have given room for less use of personal respiratory protection as the air in the working environment is safe to breath.
Elkem Carbon, Fiskaa, Norway is also participating in a national survey on moss quality in the areas around Norwegian production facilities. This includes determination of PAHs and metals in moss and PAHs in air.
Reduction of PAH emissions to water
Efforts are ongoing at all Elkem Carbon plants worldwide to reduce the amount of water used in production. PAH emissions to water from Elkem Carbon Fiskaa, Norway have been heavily reduced from around 650 kg to around 10 kg per year. Extensive maintenance has been carried out on the water pipes to avoid leaks, and new piping has been installed, in order to separate water streams into clean cooling water and contaminated water. This makes it possible to treat the contaminated surface water and measure emissions. Since 2010 Elkem Carbon Fiskaa, Norway has been monitoring the water and sediment quality for PAHs in the neighbouring fjord (Kristiansandsfjorden).
Elkem Carbon Ferroveld in South Africa has an integrated process water treatment system on site. Contaminated water from the extruder facility is transferred to process water used for cooling chrome slag at another production facility in the industrial park. In this process contamination is destroyed and water evaporated instead of being discharged. In tropical regions, biological methods for water purification can be used to remove PAHs and other contamination from rainwater and other storm water.
At Elkem Carbon’s plant in Brazil, water that may be contaminated is fed through three basins: one containing old wood materials, one containing plants, and one containing bacteria. This purification method will also be adopted at Elkem’s new plant in Malaysia.
Elkem Carbon uses coal tar pitch as a binder. Coal tar pitch contains polycyclic aromatic hydrocarbons (PAHs). These are a group of over 100 different chemicals that are formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances like tobacco or charbroiled meat. Some of these chemicals have been defined as carcinogenic, meaning exposure to them may cause cancer. Industry, road run-off and sewage are typical sources of PAH emissions.