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:
Sep. 06, 1983
Filed:
Nov. 10, 1981
Adriano Mattera, Novara, IT;
Marino Quaglino, Novara, IT;
Pasqualino Spighi, Ancona, IT;
Massimo Stolfi, Milan, IT;
Istituto Guido Donegani S.p.A., Novara, IT;
Abstract
Disclosed is a process for removing boron compounds from aqueous effluents. The effluents are contacted, under stirring, with a divalent metal sulphate Me.sub.I SO.sub.4 and a divalent metal hydroxyde Me.sub.II (OH).sub.2, the sulphate-hydroxyde couple being selected from the group consisting of BeSO.sub.4 --Ba(OH).sub.2 ; BeSO.sub.4 --Sr(OH).sub.2 ; BeSO.sub.4 --Ca(OH).sub.2 ; MgSO.sub.4 --Ba(OH).sub.2 ; MgSO.sub.4 --Sr(OH).sub.2 ; MgSO.sub.4 --Ca(OH).sub.2 ; CaSO.sub.4 --Ba(OH).sub.2 ; CaSO.sub.4 --Sr(OH).sub.2 ; SrSO.sub.4 --Ba(OH).sub.2 ; ZnSO.sub.4 --Ba(OH).sub.2 ; ZnSO.sub.4 --Sr(OH).sub.2 ; ZnSO.sub.4 --Ca(OH).sub.2 ; CdSO.sub.4 --Ba(OH).sub.2 ; CdSO.sub.4 --Sr(OH).sub.2 and CdSO.sub.4 --Ca(OH).sub.2. The sulfate Me.sub.I SO.sub.4 and the hydroxide Me.sub.II (OH).sub.2, by reaction with each other, cause the sulphate Me.sub.II SO.sub.4 and the hydroxide Me.sub.I (OH).sub.2 to precipitate. The amount of Me.sub.II (OH).sub.2 is at least stoichiometric in respect of the amount of Me.sub.I SO.sub.4 and the precipitation pH is within the range of 7 to 10 when Me.sub.I SO.sub.4 is ZnSO.sub.4, and 10 to 13 in the other cases. At the end of the precipitation the mixture is subjected to decantation and to filtration or centrifugation, thus separating the boron-containing precipitate from the purified effluents.