PCC6 is an extremely concentrated acid pickle based on Inhibited Phosphoric Acid. It is similar to PCC10, and as such is designed especially for the removal of Millscale and Rust from steel surfaces. However the product contains additional surface active agents which impart good de-greasing properties. PCC6 contains an inhibitor to prevent corrosion, coupled with low foaming characteristics.
The product is diluted with water prior to use. The dilution rate is dependent upon the type and amount of contamination involved. It has been found that for removing rust a dilution of 10%-15% v/v is sufficient. For removing millscale a higher concentration of 20%-25% v/v is ideal.
PCC6 is operated in the pre-treatment tank at temperatures up to 800C.
To test the product the following instructions should be followed: –
In a conical flask (250cm3) place a sample (10cm3) of the diluted PCC6. Add a few drops of Bromocresol green indicator the titrate with Sodium Hydroxide solution (N). The end point is reached when the colour changes from yellow to blue.
When first setting up a tank, it may be found advantageous to use Phenolphthalein as indicator as this gives a clearer colour change. However, twice the amount of Sodium Hydroxide solution has to be used and this method of checking becomes inaccurate once the tank has been in use.
DILUTON AMOUNT OF SODIUM HYDROXIDE
BROMOCRESOL GREEN PHENOLPTHALEIN
12.5% v/v 15 cm 3 30cm 3
22.5% v/v 26 cm 3 52cm 3
Use these figures for “In use” testing and Setting up Use these figures for “In use” Setting up only