# Making a tumbler for refining operations



## 4metals (May 16, 2022)

Often there are refining processes which benefit greatly from movement to agitate the load or move the solution. I am using this thread to solicit descriptions of our own members systems and give details of one I have used successfully.

For the process of both reducing silver chlorides by the caustic / corn syrup method or the 10% sulfuric iron method this system is effective. It is also effective for cyanide stripping as well.

The crux of the mixer is a small bucket called an odd job mixer. It is used to hold a bag of pre mix concrete and roll it on the floor to mix it. It has lifters to mix the load as it spins. It is pictured below in the attachment.

But laying it on the floor and rolling it about is great for mixing fluxes, it is best while processing chemicals that it be rotated at an angle of about 45° to keep the liquid contained

That is done by buying one of these small inexpensive cement mixers, taking out the paddles and removing the top half so the odd job mixer will fit inside and rotate. I used some wood shims to lock it in place so it stays put. It rotates at about 35 rpm so it’s good to keep the lid screwed on the odd job mixer when using it. Simply set the angle to about 45° and let it spin.

I have used similar tumblers and controlled the speed much slower to get slow speeds like 10 rpm and used this for aqua regia digestions. Some of the motors on these can be slowed by a simple rheostat and others cannot for electrical reasons I don’t understand. Perhaps some of our electrically inclined members could explain that for us.

By controlling the speed and making the odd job mixer removable, I have used separate odd job mixers for aqua regia, cyanide, and silver chloride reductions. I always reserved a separate odd job cylinder for each type of processing for safety reasons.

For aqua regia, with a slow spin, I added a small (1 1/2”) hole to the lid and put an exhaust drop to run the NOx through the scrubber.

All in all this simple setup can be quite versatile for a refining operation.


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## Ohiogoldfever (May 16, 2022)

Thanks for the post. I wasn’t aware of these odd job mixers. I was envisioning heating a bucket and pressing a lines into several places allowing for something close but more rudimentary.


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## snoman701 (May 16, 2022)

Here it is looking all pretty. This was long long ago. 

To the right you can see a miniature rotary converter as well.


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## Shark (May 16, 2022)

snoman701 said:


> Here it is looking all pretty. This was long long ago.
> 
> To the right you can see a miniature rotary converter as well.


You beat me to it. 

I was just reading the thread where you first posted that picture.


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## 4metals (May 16, 2022)

What are the RPM's and how do you regulate it?

Anyone who has had on of these rotating buckets in their shop can surely attest to their versatility and usefulness. Thanks for posting another option for the same concept.


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## snoman701 (May 16, 2022)

The motors speed is 1750 RPM, the gearbox brings it down by a factor of 10, or 175 RPM, which is way too fast. That is a 90 volt dc motor controlled by a dc motor controller. I have another lab tumbler planned, and am working around a variable frequency drive and a 3 phase motor.


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## Shark (May 16, 2022)

This is what I used to build one out of. It recently had motor problems and I am in the middle of redesigning it for a rebuild.


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## snoman701 (May 16, 2022)

Are those odd job mixers always $100+ ea or did I only find the overpriced one?


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## 4metals (May 16, 2022)

I remember $30 but that was pre pandemic. So……Maybe that’s right 



Scepter ODJOB Mixer | Toolmonger


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## Shark (May 16, 2022)

I found this one at a junk store, less the motor and motor mount for $5 At the time I had no idea what to use it for but the price was to good to pass up.


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## PeterM (May 17, 2022)

Shark said:


> This is what I used to build one out of. It recently had motor problems and I am in the middle of redesigning it for a rebuild.



Great Find...


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## kurtak (May 17, 2022)

4metals said:


> That is done by buying one of these small inexpensive cement mixers


The cement mixer (from harbor freight) you have pictured is one of the best investments I ever made (paid $150 on sale)



4metals said:


> For the process of both reducing silver chlorides by the caustic / corn syrup method or the 10% sulfuric iron method this system is effective. It is also effective for cyanide stripping as well.


Besides using a cement mixer for those processes it also works VERY WELL as a ball mill - at least for milling IC chips - over the course of 4 years (at the peak of my refining days) I ran something like 2500 pounds of IC chips through that little cement mixer milling IC chips

The first 50/60 pound batch of chips *WAY MORE* then paid for the cement mixer

also used it for milling larger batches of gold plated pins that were in their plastic housings (after incinerating them - like IC chips) as well as mixing (ball milling) flux in with material going to smelting

That little cement mixer (that only cost $150 on sale) did nothing but make money for me from the first day I bought it

Kurt


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## snoman701 (May 17, 2022)

4metals said:


> I remember $30 but that was pre pandemic. So……Maybe that’s right
> 
> 
> 
> Scepter ODJOB Mixer | Toolmonger



Yeah, a majority of the things I like are on the "2x4" inflation schedule. 

Except silver, it has largely left us unimpressed during this time of high inflation. Where's a hunt brother when you need one.


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## Shark (May 17, 2022)

snoman701 said:


> Are those odd job mixers always $100+ ea or did I only find the overpriced one?


The only one I have found so far is $127. $30 would be great.


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## 4metals (May 17, 2022)

I think the company that made them Scepter is in the rotational molding business and they don’t make it anymore. Too bad, I’ll keep looking but it isn’t looking good.


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## snoman701 (May 18, 2022)

Pretty much all rotational moulding tanks are on a ridiculous backorder right now, so it's hard to say.


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