The Evaluation of Paper Sludge (PS) for Zeolite Synthesis (Part 2)

We have been investigating zeolite synthesis from paper sludge (PS) ashes. This technique is essential from the viewpoint of recycling of wasting materials.In our previous study, the PS ashes from 20 paper mills in Fuji area of Shizuoka Pref. were examined on suitability for starting materials in the zeolite synthesis, and they were classified into 4 types of compositional ranges in terms of talc-kaolinite-calcite composition ; that is, ranges (A) and (B) were suitable for the zeolite synthesis and ranges (C) and (D) were not suitable.In this study, we selected representative 4 mills that had discharged PS corresponding to the above 4 types of compositional ranges, and the chemical and mineralogical compositions of PS from these 4 mills were analyzed for 5 days. As a result, the following conclusions were obtained.The PS samples from the mills that had initially discharged PS belonged in the ranges (A) and (B) did not change into the ranges (C) and (D) for the period of 5 days. The samples belonged in (A) and (B) showed again being suitable for the zeolite synthesis.PS discharged from a paper mill that makes products including a lot of kaolinite is suitable for the zeolite synthesis. However. PS containing too much calcite is not suitable.