Potassium permangante mixing

[ashtree]

I am having trouble with a potassium permanganate dosing system. The system is operating from a solution batch tank that has a concentration of 25kg/1000 liters with a water temperature of about 20 degrees C. This should be well under the solubility limit at this temperature which is about 63kg/1000 liters.

We seem to end up with a lot of solids in the batch tank which goes on to block up the dosing lines and dose pumps. The batch tank is typically mixed for several hours but is not normally mixed again until re-batching is required. This worked well for some time(5 months of continuous operation) but we then started having trouble with regular blockages.

The chemical being used is dry granules/powder that is packed in buckets. They may not have all been from the same batch but have come from the same manufacturer and supplier.

I have done this in other plants without problems, but am interested on other peoples experience on the need for mixing continuously or whether it is common to have insoluble residue from the permanganate powder.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[bimr]

"Potassium permanganate products are pure granular products used in applications where less concentrated levels of permanganate are needed to oxidize specific contaminants. Sodium permanganate products are sold as water soluble solutions in varying concentrations where ease of handling is a criterion for use. While there is no significant difference between the chemical properties of sodium and potassium permanganate, there is a significant difference in the physical property between both permanganates, specifically their solubility in water. The potassium permanganate, although available as a 97% solid, can only be applied as a 3-4% solution because of the solubility limits. Sodium permanganate is soluble up to 40%, providing a solution that can be applied in much higher concentrations."

http://www.caruscorporation.com/res...ssium-permanganate-product-safety-summary.pdf

 

[QualityTime]

I would double check if the batching process is accurate. Things could go out of calibration