Back to results
US 5,211,215 AGranted
Process for neutralizing regenerated sand
OwnerHermann W. Sommerinventor
Life of this patent
Estimating the term…
Abstract
Sand containing clay binder after regeneration is neutralized with NH.sub.4 OH as a base or sulfuric acid or hydrofluoric acid depending on its pH-value determined after regeneration by a measuring procedure, so that it subsequently has a pH-value between 6 and 8.
Claims11
A process for neutralizing regenerated sand, comprising the steps of:
- measuring the pH of regenerated sand, the regenerated sand containing a clay binder;
- and,
- neutralizing the regenerated sand with a neutralizing agent being either an acid or a base and selected from the group consisting of sulfuric acid, hydrofluoric acid and NH.sub.4 OH, said neutralizing agent being said acid if the pH of the regenerated sand, as determined during said measuring step, is basic and said neutralizing agent being said base if the pH of the regenerated sand, as determined during said measuring step is acidic, the regenerated sand having a pH-value of between 6 and 8 following said neutralizing step.
Dependencies are inferred from the claim text.