Recycling of waste papers: yield and quality of the ash-derived materials

Abstract

This research was designed to assess the yield and quality of ash prepared from different types of waste papers. Waste newspapers, writing papers, and cartons were selected for combustion to obtain the ashes and coded as WNPA, WWPA, and WCPA, respectively. The waste papers were incinerated simultaneously in separate but identical incinerators at 850 ℃. An experiment on the yield of the ashes was performed on two days before the ashes obtained were mixed based on the type of waste papers from which they were derived. The results showed that irrespective of the day and time, the WCPA was the most yielded (14.1%), followed by the WWPA (12.3%), and then the WNPA (11.9%). Also, it was found that all the ashes possessed flow properties acceptable for engineering applications. However, the WCPA would ensure the best performance if applied, especially as a partial replacement material for cement. While the WWPA was found to be richer than the WNPA, the WCPA was the richest in terms of the proportions of key oxides for strength development. In general, the percentages of various chemical components of each ash complied with the standard specifications for cement except in the case of losses on ignition of the WNPA and WWPA, which were about 0.53% and 0.02%, respectively, beyond the maximum stipulated value.