摘要 |
In a process for the recovery and re-use of raw materials from paper mill waste sludge, the sludge is subjected to a preliminary cleaning treatment at a relatively low consistency, thickened to a consistency of 10 to 30%, heated to at least 100 DEG C. and then passed through a disperser in the thickened heated state before being passed to a papermachine for re-use. Papermaking fibre from at least one other source is mixed with the sludge before and/or after treatment as just described, so that the final paper product typically contains up to 30% of raw materials recovered from sludge. The action of the disperser is to break up dirt and other debris, and as a result, the recovered raw materials can be re-used in the manufacture of high quality fine papers.
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