| Abstract: | Reducing fiber rejection loss in flotation deinking is very important to conserve natural resources and reduce the cost of secondary fibers in paper recycling. This study examined two aspects of the problem, fiber consistency in the rejection stream and rate of froth (or wet stream) rejection. Flotation experiments were conducted using both nylon and wood fibers in column and commercial bench‐scale flotation deinking cells. It was found that increased froth stability resulted in a lower fiber consistency in the wet reject stream. However, it also increased rejection rate of the wet stream. As a result, the total fiber rejection loss was increased with the increase of froth stability. The results obtained suggest that controlling froth stability through reducing frother application and froth rejection are effective ways to reduce fiber yield loss in flotation deinking. This study also experimentally measured water and fiber drainage in fiber suspended froth to explain the effect of froth stability on fiber consistency in the reject stream using froth drainage dynamics. |
