Owner manual

11
Section 4
Resin Conversion
Table 5 outlines common techniques for converting
ion exchange resins from one ionic form to another.
Resin conversion is most efficiently carried out in the
column mode. However, when choosing a column,
remember that the resin may shrink, or it may swell as
much as 100%, depending on the conversion.
10
Table 5. Techniques for Resin Conversion
Volumes of Linear Test for Rinse:Vol. Test for
Conversion Sol’n/Vol. Flow Rate
(4)
Type of Completeness Dl Water/ Completion
Resin From→To
(1)
Reagent Used of Resin cm/min of Bed Exchange
(3)
of Conversion Vol. Resin of Rinsing
AG 1 and Cl
–
→ OH
–
1 N NaOH
(2)
20 IX Cl
–(5)
4 pH<9
AG MP-1 OH
–
→ formate 1 N formic acid 2 2 N pH<2 4 pH>4.8
Resins Cl
–
→ formate Use Cl
–
→ OH
–
and 20 IX-N pH>4.8
then OH
–
→ formate 2 pH>4.8
Cl
–
→ acetate same as formate except IX-N pH<2 4 pH>4.8
use 1 N HAc
AG 2 Resin Cl
–
→ OH
–
1 N NaOH
(2)
2 2 IX Cl
–(5)
4 pH>9
Cl
–
→ NO
3
–
0.5 N NaNO
3
5IXCl
–
(
5)
4
1. Typical conversions are listed. The same reagents can be used to con-
vert from other ionic forms. Two steps regeneration, ion exchange fol-
lowed by neutralization, is included because of ease of conversion and
saving on expensive reagents.
2. Use U.S.P. or C.P. grade (low chloride).
3. N = Neutralization; IX = Ion exchange; IXN = two step process: Ion
exchange to acid or base form followed by neutralization with appro-
priate base or acid of salt, example (Step 1) Resin-Cl
–
+ NaOH →
Resin-OH (IX); (Step 2) Resin-OH + H-formate → resin-formate +
H
2
O (neutralization).
4. For 50-100 or finer mesh resin. For 20-50 mesh about
1
⁄5 the flow rate
is recommended
5. Test for Cl
–
in effluent: Acidify sample with a few drops of conc.
HNO
3
. Add 1% Ag NO
3
solution. White ppt indicates Cl
–
, yellow Br
–
or too basic.
LIT212C 6/17/98 12:25 PM Page 10