Stuff floating in new coolant

[Sunnyinhollister]

At work we use coolant in our industrial chillers. These are the ones we use:

http://tek-tempinstruments.com/tektemp_product/nrd-550-liquid-to-liquid/

The chillers run at about 28C - 33C. At first we were using Dexcool. The problem we ran into was that our flow meters started leaking and we also had a few pump seal failures. So we switched over to Zerex original green. This eliminated the leaks but soon afterwards we started plugging the 50 micron water filters that are on the output of the chillers. At first we suspected that the original Dexcool was not flushed adequately so we flushed again, and again, and again. Then we figured out that there was some type of organic bacteria or slime growing inside the reservoir of the chiller so we started cleaning out the reservoir, flushing the system with 30% H2O2 and refilling with a mix of the Zerex original green 50/50 and Distilled water. Upon refilling the clean reservoir we noticed the new coolant had a lot of stuff floating in it. We checked some other new sealed containers and they had the same stuff in it. Here's a picture:

https://www.dropbox.com/s/dnz8lf0gd8kawc3/DSC01305.JPG?dl=0

I sent it off to Valvoline and they said it was magnesium. I didn't know that magnesium was used in coolant. Anyone know what exactly it does in coolant?

Thx

 

[Falken]

Dexcool used to not play nice with other coolants, would create a jelly or "mud".

Huge problems in the past with Dexcool.

Maybe I am wrong, but I would say flush immediately and use Dexcool again and be careful with mixing Dexcool with anything else.

 

[Sunnyinhollister]

We are trying to figure out the next step, but we are also curious as to what is floating around in the brand new unopened coolant. We also have to figure out what is growing in our system. What you are seeing is from sealed containers and I can't find a reference for magnesium being used in coolant.

 

[KGMtech]

Time to call the manufacturer of the coolant.

 

[Sunnyinhollister]

I did that and sent them a sample. They are saying it is magnesium. It does not look like magnesium.

 

[Xrs2zz]

I bought two gallons of Zerex Asian a few months ago and saw the same white flakes in both jugs. I didn't notice them until I had used almost the whole first gallon. I put a sample in a jar and heated it up. After I stirred the sample the flakes dissolved. I have no idea why they formed, but thankfully they seemed to dissolve.

Looking back, I probably should have dumped and flushed out the system, and returned the jugs for new coolant. But after a few months in the car those flakes are gone and no issues have popped up.

 

[camrydriver111]

Originally Posted By: Sunnyinhollister
I did that and sent them a sample. They are saying it is magnesium. It does not look like magnesium.


It's not going to be elemental magnesium.

When heated the flakes will dissolve. They must be some additives that are precipitating. I wouldn't worry about it myself.

 

[KrisZ]

I would contact the manufacturer of these chillers and see what they recommend instead of guessing and experimenting with different coolants.