|
Process step |
% |
Products |
°C |
Running Time |
Remarks |
|
Pre-soak |
300 |
water |
28 |
|
|
|
|
0.2-0.3 |
Negahdar Ist-WB |
|
|
|
|
|
0.2 |
Rockol 642 |
|
run 30 mins. |
|
|
|
|
|
|
rest 30 mins |
|
|
|
|
|
|
run 30 mins. |
|
|
Drain |
|
|
|
|
|
|
Main soaking |
200 |
water |
28 |
|
|
|
|
0.3-0.4 |
soda ash |
|
|
|
|
|
0.3-0.5 |
Negahdar IST-WB |
|
|
|
|
|
0.1-0.2 |
Rockol 642 |
|
run 30 mins. |
|
|
|
|
|
|
leave automatic |
|
|
|
|
|
|
rest 45 mins. |
|
|
|
|
|
|
run 5 mins. |
|
|
|
|
|
|
total time 16-18 hrs |
pH= 9.2-9.5 |
|
|
|
|
|
|
Be < 3.5 |
|
Drain |
|
|
|
|
|
|
Liming |
70 |
water |
28 |
|
|
|
|
1.5 |
sodium hydrosulphide,72% |
|
run 30 mins. |
|
|
|
|
|
|
rest 30 mins. |
|
|
|
1.0 |
sodium sulphide,60% |
|
|
|
|
|
1.0 |
hydrated lime |
|
run 30 mins. |
|
|
|
|
|
|
rest 30 mins. |
|
|
|
1.5 |
sodium sulphide,60% |
|
|
|
|
|
1.5 |
hydrated lime |
|
run 30 mins. |
|
|
|
|
|
|
rest 30 mins. |
|
|
|
1-1.5 |
sodium sulphide,60% |
|
|
|
|
|
1.0 |
hydrated lime |
|
run 30 mins. |
|
|
|
|
|
|
leave automatic |
|
|
|
|
|
|
run 5 mins |
|
|
|
|
|
|