philddreamer
Well-known member
I haven't used any... for the water lines, I've used threaded couplings; the elbows are just fitted tight. They don't leak.
For the drain valves, I use threaded valves and Teflon tape, so no "glue" either.
Phil
Mild Carbon Steel Sulphuric Cell
- Thread starter philddreamer
- Start date
Help Support Gold Refining Forum:
I haven't used any... for the water lines, I've used threaded couplings; the elbows are just fitted tight. They don't leak.
For the drain valves, I use threaded valves and Teflon tape, so no "glue" either.
Phil
- Joined
- Apr 8, 2014
- Messages
- 52
Thanks Phil,
Here is the link to the compatibility listing:
https://www.calpaclab.com/pvc-polyvinyl-chloride-chemical-compatibility-chart/
Basically it says it OK as long as not too concentrated (less than 75%) and at low temperature (less than 22C).
Phil's system got good cooling so that is important. How about concentration?
The very old US patent 2,185,858 listed a minimum of 73%
Here is the link to the compatibility listing:
https://www.calpaclab.com/pvc-polyvinyl-chloride-chemical-compatibility-chart/
Basically it says it OK as long as not too concentrated (less than 75%) and at low temperature (less than 22C).
Phil's system got good cooling so that is important. How about concentration?
The very old US patent 2,185,858 listed a minimum of 73%
You need your sulfuric acid at around 95% give or take a few percent. At 75%, the acid will attack base metals.
Dave
Dave
philddreamer
Well-known member
Thank you, gentlemen!
I use LIQUID FIRE, it's 96% to 98%... I've found it at Ace Hardware, for about $25.00 /gal... they also have ROOTO, I don't recommend it... it has buffers and the acid will foam and makes things messy!
A WARNING!!! Be very careful when there's foam on top of the acid while de-plating!!! If there's a spark while connecting or disconnecting the terminals and it reaches the foam, it will BANG!!! :shock:
So use a face shield and safety gear!!
I once bought some sulphuric from a chemical outfit, $50.00/gal! :?
Needless to say, I now buy it at Ace! :mrgreen:
Phil
I use LIQUID FIRE, it's 96% to 98%... I've found it at Ace Hardware, for about $25.00 /gal... they also have ROOTO, I don't recommend it... it has buffers and the acid will foam and makes things messy!
A WARNING!!! Be very careful when there's foam on top of the acid while de-plating!!! If there's a spark while connecting or disconnecting the terminals and it reaches the foam, it will BANG!!! :shock:
So use a face shield and safety gear!!
I once bought some sulphuric from a chemical outfit, $50.00/gal! :?
Needless to say, I now buy it at Ace! :mrgreen:
Phil
- Joined
- Apr 8, 2014
- Messages
- 52
A followup on my questions about Sulfuric Acid and PVC compatibility.
I am testing compatibility of PVC and sulfuric acid at room temperature and at 65C.
I got samples of regular white plumbing PVC, gray electrical PVC, and a blue PVC piece from an 8" pipe.
The available sulfuric acid is very old and has absorbed some water. The density measured 1.74 = 81%
Both sample sets have been tested by now for 30 hours without any visible changes.
The acid on the hotplate presumably has been concentrated by now with water being driven off. Unfortunately the testing volume is too low for me to accurately retest the acid. (the test procedure requires 50ml). Regardless, I need to order some 98% acid.
I am testing compatibility of PVC and sulfuric acid at room temperature and at 65C.
I got samples of regular white plumbing PVC, gray electrical PVC, and a blue PVC piece from an 8" pipe.
The available sulfuric acid is very old and has absorbed some water. The density measured 1.74 = 81%
Both sample sets have been tested by now for 30 hours without any visible changes.
The acid on the hotplate presumably has been concentrated by now with water being driven off. Unfortunately the testing volume is too low for me to accurately retest the acid. (the test procedure requires 50ml). Regardless, I need to order some 98% acid.
kernels
Well-known member
Bertho, this is all secondhand information but . . .
I have dealt a bit with a company doing E-waste recovery in reasonable volumes, like 6000L reaction chambers. I was surprised to see them using PVC pipes to transfer concentrated Sulfuric Acid around, was told that their chemists had OK'ed it, even though both myself and the guy I was talking to were dubious about it.
I have dealt a bit with a company doing E-waste recovery in reasonable volumes, like 6000L reaction chambers. I was surprised to see them using PVC pipes to transfer concentrated Sulfuric Acid around, was told that their chemists had OK'ed it, even though both myself and the guy I was talking to were dubious about it.
- Joined
- Apr 8, 2014
- Messages
- 52
An update to my post from July 21 On PVC testing.
It is now 5 days without any effect.
I bought the suggested Liquid Fire from Ace Hardware and very carefully measured the density @ 25°C = 1.823 That translates to 93%.
How do people measure higher % Acid? Looking at density charts, the highest density is at 97%
100% density,1.8255 is the same as 94%
I am assuming my acid to be on the low side of the density peak since I doubt I received 100%.
It is now 5 days without any effect.
I bought the suggested Liquid Fire from Ace Hardware and very carefully measured the density @ 25°C = 1.823 That translates to 93%.
How do people measure higher % Acid? Looking at density charts, the highest density is at 97%
100% density,1.8255 is the same as 94%
I am assuming my acid to be on the low side of the density peak since I doubt I received 100%.
- Joined
- Apr 8, 2014
- Messages
- 52
I saw Phil's comment about filtering the acid and fine particles. I do not look forward to that phase.
Is there an alternative? In my case, with a PVC cell, I will have a separate electrode. Could it be "bagged" to catch the particles? Basically the reverse of the bag for a silver cell. Or maybe a cup or glass under/around it to catch the particles.
Is there an alternative? In my case, with a PVC cell, I will have a separate electrode. Could it be "bagged" to catch the particles? Basically the reverse of the bag for a silver cell. Or maybe a cup or glass under/around it to catch the particles.
