Material input and output
The main output from the paper mills is of course paper. This includes about 2 kg of cores and plugs per tonne paper, which are considered and weighed as part of the net saleable product. The corrugated board plants produce corrugated board and boxes.
The average moisture content of the saleable product is 9% for Semichemical Fluting and 8% for Kraftliner, 7,5% for Testliner and Wellenstoff, 7-8% for corrugated board.
The main saleable by-products from the production of Kraftliner are tall oil and turpentine. These are included in the report.
All residues are reported as wet weight, separated according to their basic nature. Residues are reported irrespectively if they are deposited internally within the site or externally, in the latter case normally at a deposition cost.
The waste treatment was not reported by all mills.
From the residues of the recycled paper mills, which are mainly rejects from the pulp preparation, about 75% consist of waste that is not due to the previous use of the paper. The previous use of the paper and properties of paper cause the other 25% of the rejects: paper clips, tags, adhesive labels, fibres etc. The average dry mass of the rejects is about 50%.
Primary sludge from wastewater treatment in mills producing Testliner and Wellenstoff are mostly recycled in the process and do not leave the site.
|fibre primary sludge||29%||18%||0%||0%||0%||52%||1%|
|biological treatment sludges||7%||9%||9%||3%||0%||70%||3%|
Ashes, green liquor sludge and lime mud are commonly reported residues from the production of primary fibre based paper. They are usually landfilled (LO), but lime mud is also used as fertilizer.
For corrugated board the main waste stream is paper for recycling, which is recycled and thus should not be called waste but recyclable material.
Allocation of residues to paper grades when a mill produces more than one paper grade
Data for material outputs are based on measurements. These have to be done because the mills have to pay for landfill and incineration, or get paid for residues that are reused or recycled, like lubricants, according to the weight. When allocation was necessary, this was done according to mass of the different paper production.
There is no technical reason for differences in residues between Testliner and Wellenstoff. However the weighted averages for each paper grade do show differences because different mills are included in the samples. To prevent misunderstanding, the same amounts of residues for both paper grades are reported as their weighted average.