The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 1993
Filed:
Oct. 05, 1990
Richard L Morris, Duncanville, TX (US);
James M Paul, DeSoto, TX (US);
Mobil Oil Corporation, Fairfax, VA (US);
Abstract
Barium sulfate scale is dissolved by contacting the scale with an aqueous solvent having a pH of about 10 to about 14, preferably about 12, and comprising a chelating agent comprising a polyaminopolycarboxylic acid or salt of such an acid, and a synergist anion. The solvent containing the dissolved scale is regenerated by acidifying the solvent in the presence of an anion which forms a precipitate of an insoluble salt of the alkaline earth metal of the dissolved scale. The precipitate is then removed from the solvent. Thereafter, the pH of the solvent is increased to a pH of about 10 to about 14, preferably about 12, to recover a regenerated solvent for reuse, in dissolving scale.