Methods for removing metals from plating operation
View Patent ↗The present invention relates to compounds and methods for removing metals, e.g., ionic cobalt from an electroless plating operation, preferably to levels less than 5 ppm. The metals can then be either landfilled or regenerated for electrowinning and reuse. The invention utilizes an ion exchange media comprised of a silica backbone and functionalized with phosphonate groups.
1. A method of removing metals from an electroless plating operation, comprising adding to said operation a composition including a compound of Formula 1:
wherein R and R 1 are each independently hydrogen, a linear or branched C 1-40 alkyl, C 2-40 alkenyl or C 2-40 alkynyl group, an aryl or C 1-40 alkylaryl group or optionally a complex metal ion M n+ /n wherein n is an integer from 1 to 8; the free valences of the silicate oxygen atoms are saturated by one or more of: silicon atoms of other groups of Formula 1, hydrogen, a linear or branched C 1-12 alkyl group or by cross-linking bridge members R 3 q M 1 (OR 2 ) m O k/2 or A1(OR 2 ) 3-p O p/2 or R 3 A1(OR 2 ) 2-r O r/2 ; where M 1 is Si or Ti; R 2 is a linear or branched C 1-12 alkyl group; and R 3 is a linear or branched C 1-6 alkyl group; k is an integer from 1 to 4 and q and m are integers from 0 to 2; such that m+k+q=4; and p is an integer from 1 to 3; and r is an integer from 1 to 2; or other oxo metal bridging systems; x, y and z are integers such that the ratio of x:y+z, varies from 0.00001 to 100,000 with the fragments [O 3/2 SiCH(CH 2 PO(OR)(OR 1 ))CH 2 CH 2 SiO 3/2 ] x and [O 3/2 SiCH 2 CH 2 PO(OR)(OR 1 )] y always present while the integer z varies from 0 to 200y.
2. The method as recited in claim 1 , wherein the amount of compound is from about 0.5-5 mmole/g.
3. The method as recited in claim 1 , wherein the metals are removed from the electroless plating operation to levels less than 5 ppm.
4. The method as recited in claim 1 , wherein said metals include cobalt.
5. The method as recited in claim 4 , wherein the cobalt can be regenerated for reclamation.
6. The method as recited in claim 1 , wherein the particle size of the compound utilized is from 5-500 um.
7. The method as recited in claim 6 , wherein the particle size of the compound utilized is from 20-100 um.
8. The method as recited in claim 1 , wherein the compound is used in conjunction with a nanofilter.
9. The method as recited in claim 1 , wherein the pH of treatment is from 6-10.
10. The method as recited in claim 9 , wherein the pH of treatment is ftom 7.5-9.