Improving the pozzolonic character of fly ash for use in Portland cement concrete - 0789
- *Abstract
-
Overview
Therole of pozzolan in Portland cement concrete is to react with excessportlandite to improve the strength of the resulting concrete. Previous proceduresexist which effectively enhance the pozzolatic qualities of fly ash forsubsequent use in portland concrete cement, but these procedures are high-maintenance and require the use of capital intensive equipment to complete. Tocombat these issues, UK researchers are developing a method for improvingthe pozzolanic character of fly ash so that it is a commercially useful productas an admixture for Portland cement concrete.
Invention
UK researchers are developing a method for improving thepozzolanic character of fly ash. The method includes the combined efforts ofhydraulic classification and spiral concentration, which allow for all iron,pyrite and marcasite particles to be removed from the fly ash without utilizingexpensive magnetic field generating equipment. Furthermore, the ability toprocess ponded material, as opposed to only land filled or dry material, allowspozzolanic production to be controlled by normal market demand rather than bythe rate of power generation, as it is at the present. The resulting enhancedpozzolan may command a higher price in the cement admixture market,significantly improving the economics of fly ash processing.
Advantages
- highly efficient use of hydraulicclassification
- can be used with any class of fly ash--ponded, land filled or dry
- enhanced pozzolan commands higherprice in cement admixture market
IP Status: U.S. Patent No. 5,817,230
- Country/Region
- USA
