Paper recycling processes can use either chemically or mechanically produced pulp; by mixing it with water and applying mechanical action the hydrogen bonds in the paper can be broken and fibres separated again. Most recycled paper contains a proportion of virgin fibre for the sake of quality; generally speaking, de-inked pulp is of the same quality or lower than the collected paper it was made from.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): What type of processes can only use mechanically produced pulp?
unanswerable