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:
Jul. 28, 1992
Filed:
Feb. 28, 1991
Ankur Purohit, Darien, IL (US);
Ahnal A Purohit, Darien, IL (US);
Anshal, Inc., Darien, IL (US);
Abstract
The invention teaches a deep boiling process for refining diamonds, be they raw or cut and polished. The process provides for initially precleaning the diamonds with solvents including alcohol, acetone, sulfuric acid, hydrogen peroxide, and/or water, to remove surface oils, hydrocarbons and other common surface impurities therefrom. The process then provides the use of separate sealed vessels wherein the diamonds are respectively submerged in strong caustic and acid solvents, and heated to between 220.degree. and 500.degree. C. with associated high vaporous pressures, for durations of possibly more than a day. The caustic solvent comprises potassium hydroxide and/or sodium hydroxide and possibly also potassium nitrate, and breaks down and removes the 'glassy' structures and other complex oxides in the diamonds; while the acid solvent comprises Aqua Regia [hydrocholoric acid and nitric acid] and possibly also sulfuric acid, and removes metallic traces in the diamonds by forming water soluble chlorides and nitrates. The diamonds are rinses, between exposures to the caustic and acid solvents and after the last exposure to either, with solvents including water, acetone and/or alcohol. Vessels suited to preform this process are also disclosed.