Abstract: A method for inhibiting the formation of scale in waters having a high barium content and low pH comprises the addition of an aqueous solution of a phosphonate of formula:
wherein
Z=—CHR1PO3R2
R=H, CH3, C2H5 or M
R1=H, CH3, CR3, C6H5, SO3H2
M=alkali metal or ammonium ion
n=2-6, preferably 2-4
m=2-6, preferably 2-4
a=2-10, preferably 2-4
b=2-10, preferably 2-6
x=0-6, preferably 0-3
y=0-6, preferably 0-2
provided that when y=o at least one of n or m is greater than 2.
Type:
Grant
Filed:
September 15, 1993
Date of Patent:
March 4, 2003
Assignee:
Solutia Europe NV/SA
Inventors:
Nevin John Stewart, Patrica Alexandra Mary Walker