Graduate Thesis Or Dissertation
 

Chemical equilibrium of nonprocess elements in the kraft recovery cycle

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/fq977x75n

Descriptions

Attribute NameValues
Creator
Abstract
  • Non-process elements are present in all kraft recovery systems. Non-process elements are defined as those elements which are not essential to the chemical process, i.e., are neither active pulping chemicals (e.g., NaOH and Na₂S in the kraft process), nor compounds present as a result of incomplete conversion of makeup chemicals to active pulping chemicals. Problems associated with the build up of these elements include scaling, fouling and corrosion of heat exchangers, and various operating problems in the preparation of pulping liquors. A better understanding of the solubility of these elements in solutions similar to recovery cycles would facilitate the elimination of these problems. The solubility of aluminosilicates was measured in aqueous solutions of high ionic strengths and hydroxide ion concentrations. Temperature, ionic strength, hydroxide ion concentration and Al/Si ratio were varied to determine their effect on the solubility of aluminum and silicon. Several cations (Ca,Mg,Mn,V,Fe,K) were also studied to determine their effect on the solubility of aluminum and silicon. The results show that the solubility of aluminum and silicon increases with increasing hydroxide ion concentration and temperature, and decreases with increasing ionic strength. The solubility of aluminum and silicon was found to be a complicated function of Al/Si ratio at varying hydroxide ion concentrations and ionic strengths. Magnesium salts were found to decrease the solubility of aluminum when no silicon was present, but increase it when silicon was present. The other salts had no effect on the solubility of aluminosilicates, although calcium aluminosilicates were formed under some conditions. A thermodynamic model was developed using parameters that were obtained from the experimental solubility data. The model gives a reasonable fit to the data at 0.1 and 1N hydroxide ion concentration and can be used to estimate the solubility of aluminum and silicon in aqueous solutions where data are not available. Limitations to the model are discussed.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details StreiselRobertC1988.pdf 2017-08-14 Public Download