DESIGN OF A MODERN WASTE PAPER DEINKING PROCESS

In 1989 Australian Newsprint Mills Ltd began to consider the introduct ion of secondary fibre into the furnish used for the manufacture of ne wsprint. The issues of waste minimization, resource and energy conserv ation and the escalating concerns about the difficulty of finding adeq uate landfill sites were important motivating factors. The likely prod uct quality changes as a result of using secondary fibre were also imp ortant. The principal aims of the project team were to design a proces s which would produce high quality deinked pulp and so minimize the im pact of the new furnish on paper machine and printing press operations , to operate the new plant without increasing the mill's water consump tion and to have minimal environmental impact as a result of the plant 's operations. The problems of specks, 'stickies' and chemical consump tion are addressed in this paper and the rationale behind the process design and layout is discussed. Some commentary is given on the types of process equipment available and the selection of particular units i s discussed in detail where the plant is considered to be innovative i n its approach.