PAPER CHEMISTRY LABORATORY, INC.
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SCAVENGER EVALUATION
Purpose:
A number of cationic chemicals were evaluated for their effectiveness as scavengers of anionic trash. Anionic dispersions of ground calcium carbonate (GCC) were introduced as a source of anionic trash, at three levels: 15, 25 and 50%.
Method:
1.5 liters of bleached 50:50 HWD:SWD Kraft at 0.5% consistency was introduced to a 2 liter beaker for measurement with the Lab Zeta Datatm. The appropriate amount of GCC was added.
The cationic chemical under test was added incrementally until a zeta potential of +5 mV was reached. The percentage of added chemical was recorded as Cationic Demand, %.
After ten minutes, 0.3% of a bentonite dispersion was added and the drainage before (A) and after (B) was recorded, with the increase expressed in per cent.
Discussion:
In principle, the greater the increase in drainage, the greater the process efficiency. Very significantly, this corresponds to a commensurately greater increase in retention, at a good level of formation.
Conclusion:
The most effective cationic scavengers are the two highest on the list, when used at the 50% GCC level: Polymin SKA (BASF) and Alcofix 109 (Allied Colloids).
John G. Penniman
January 26,
1995
SCAVENGER EVALUATION
15% GCC Slurry
<![CDATA[
Cationic
Product ZP, mV Demand,% Drainage, ml
A B A B Incr.,%
Polymin SKA -14 -5 0.26 67 137 104
Alcofix 109 -16 -5 0.08 63 111 75
Alcofix 159 -19 -2 0.22 72 113 58
PR 971L -19 -3 0.22 78 113 57
Alcofix 131 -15 -6 0.09 66 76 15
Alcofix 169 -16 -4 0.12 69 79 14
Polymin PL -17 -2 0.18 75 124 66
Nalco 7607 -17 -7 0.03 72 108 49
Cypro 514 -18 -3 0.23 76 103 35
PAC -15 +3 15.5 69 45 -35
]]>
SCAVENGER EVALUATION
25% GCC Slurry
<![CDATA[
Cationic
Product ZP, mV Demand,% Drainage, ml
A B A B Incr.,%
Polymin SKA -15 -4 0.31 60 100 66
Alcofix 109 -15 -5 0.09 67 94 40
Alcofix 159 -19 -2 0.24 70 93 34
PR 971L -15 -3 0.21 66 95 43
Alcofix 131
Alcofix 169 -16 -4 0.12 69 79 14
Polymin PL -17 -3 0.18 75 100 34
Nalco 7607 -16 -2 0.04 75 85 14
Cypro 514 -16 -2 0.24 75 92 23
]]>
SCAVENGER EVALUATION
50% GCC Slurry
<![CDATA[
Cationic
Product ZP, mV Demand,% Drainage, ml
A B A B Incr.,%
Polymin SKA -17 +1 0.38 61 92 50
-18 +2 0.34 61 85 39
Alcofix 109 -17 +1 0.15 60 85 43
Alcofix 159 -19 +2 0.31 65 74 13
PR 971L -16 0 0.24 64 66 3
Alcofix 131 -19 ñ0 0.24 64 74 17
Alcofix 169 -18 +1 0.24 64 67 4
Polymin PL -18 0 0.22 69 70 2
Nalco 7607 -17 +1 0.06 68 68 --
Cypro -18 +1 0.32 71 77 8
]]>
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