Technical Bulletin No. 0074: A Description and Critical Discussion of Selected Methods Applied or Being Applicable to the Dehydration of Hydrogels Similar to Those Obtained on Clar

After a number of years of laboratory and pilot plant investigation by the National Council in cooperation with a number of mills it was concluded that existing methods are not adaptable to dewatering some of the residues obtained from the clarification of white waters. Where these residues cannot be returned to the process, disposal will prove a costly, arduous, and, in some cases, an impossible task until they can be at least partially dehydrated. Some, such as ground wood fines, are so highly hydrated that one-half percent consistencies are the best obtainable by existing methods. In order to solve this problem a fresh approach was indicated. In  accordance with this thought, the Council established a project at Syracuse University. The task assigned this project was to examine critically the literature on the dehydration of hydrogels and to select from it methods not now generally applied toward application to this problem but worthy of further study. The attached bulletin is a complete report of this investigation, While some of the methods discussed in the report do not appear worthy of pursuit, others may prove of merit. These will be investigated in the laboratory in accordance with approval for continuance of the project by the Operating Committee of the National Council.