Liquid purification or separation – Processes – Ion exchange or selective sorption
Reexamination Certificate
2005-09-02
2009-08-11
Phasge, Arun S (Department: 1795)
Liquid purification or separation
Processes
Ion exchange or selective sorption
C210S681000, C210S687000, C210S688000
Reexamination Certificate
active
07572379
ABSTRACT:
The present invention relates to a process for removing dissolved metal ions from an onium hydroxide and/or salt solution, including providing a weak acid ion exchange medium; providing a solution comprising magnesium ions; forming a magnesium-loaded ion exchange medium by contacting the ion exchange medium with the solution comprising magnesium ions; contacting the magnesium-loaded ion exchange medium with an onium hydroxide and/or salt solution containing a first quantity of dissolved metal ions, wherein at least a portion of the dissolved metal ions are removed from the onium hydroxide and/or salt solution; and collecting the onium hydroxide and/or salt solution after the contacting, wherein the solution collected contains a second quantity of dissolved metal ions smaller than the first quantity. The onium hydroxide and/or salt may be tetramethylammonium hydroxide and/or salt, and the metal content may be reduced to about 1 part per billion or less by the process.
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Niinobe Takao
Wilson Wilfred Wayne
Phasge Arun S
Renner , Otto, Boisselle & Sklar, LLP
SACHEM, Inc.
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