Process for the preparation of common salt of high purity from brines in solar salt pans

US8021442B2 · kind B2 · utility

Assignee

• COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH · IN

Inventors

• Arvind Kumar · Atlanta, US
• Indrajit Mukhopadhyay · Sayla, IN
• Pushpito Kumar Ghosh · Bhavnagar, IN
• Vadakke Puthoor Mohandas · Bhavnagar, IN
• Jignesh Jasvantrai Shukla · Bhavnagar, IN
• Rahul Jasvantrai Sanghavi · Sayla, IN

Key dates

• Filing date: Sep 29, 2008
• Grant date: Sep 20, 2011
• Expiry date: May 2, 2029

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01D3/06
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The process of the invention is an improvement over the existing process of producing salt of high purity from alum-treated brine disclosed recently in the prior art. More particularly, the invention rectifies the ratio of Ca2+ to Mg2+ from a value <1 to a value in the range of 2-3 desired by chlor-alkali and soda ash industries. The improved process involves the adjustment of pH of clarified brine with aqueous HCl so as to carry out salt crystallization at a pH of 6.5 instead of at the natural pH of 7. The pH adjustment reduces the Mg2+ impurity in salt while slightly raising the Ca2+ impurity in the salt and thereby achieving the desired ratio.