Ball mill design

[Mad Machinist]

A friend and I drew this up today. It's a cheap solution to the whole need to find a way for the small miner to quickly and cheaply process low grade ore.

This centered around a propane tank. Now before anyone blows a gasket over the propane tank idea, look here, Manchester Tank & Equipment Steel DOT Vertical Liquid Propane Cylinder Equipped with POL Valve, 100 lb. - Tractor Supply Co. Available new, rather cheaply and easily. Let me know what you think and I clean it up with some dimensions.

 

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[gold tramp]

we had a rod mill that was similar to your drawing, it worked well was a thru put system, 8 x 3 foot squared ends.

I became partial to the mixer ball plant as most of the pockets i dug were just a few buckets, the ball is your best bet for getting a good uniform classified material, and can be set up inline with an impact or jaw crusher, and finish on a table,
your idea is a good one thanks.
GT..............

 

[Mad Machinist]

gold tramp,

Good to hear from you.

The plan is to combine it with something like this:

dewatering screw - Yahoo Image Search Results


This way instead of hauling many tons of low grade ore, one can just haul a few tons of high grade.

Found the augers cheap at tractor supply. The just need either hard face or a sacrificial plate bolted to the augers.

 

[Mad Machinist]

I'm trying to keep the design both modular and cheap. So this way if a part wears out it can be easily and cheaply replaced. Or if the mill would need to be longer or shorter for a given situation it can be easily modified.

And on top of that, I am also trying to keep this highly mobile. Mount it on a trailer and go. When your done, clean it up, hook it up, and roll down the road to the next one.

Need a bigger mill?

Cheap Tanks: 100 gallon ASME propane tank for sale

 

[Oakview2]

Thanks for the research, where are you sourcing the steel balls, and what size will use in this size tank?

 

[Mad Machinist]

Thanks for the research, where are you sourcing the steel balls, and what size will use in this size tank?

1 - 3 dia. forged steel ball, 1 - 2 dia. forged steel ball items in ToolSupply store on eBay!

I also have several tons we found on an old mill site here.

As for size, I am not sure at this point, but I am thinking with the length of a 100 lb propane cylinder (15.1" dia by 70" long, I might be able to get away with using 2" balls if I crush the material down to 1/16" minus. I am hoping to get away with about 100 2" balls.

I might end up with a mix of 1" and 2" balls depending on performance and the exact length of the mill with the discharge cone in it.

The feed outlet slots in the discharge cone will be around .040". That's the kerf width of my plasma cutter. So I am thinking that maybe a trammel with 100 to 200 mesh screen needs to be put in line with this as a way to classify out larger material to be reground.

 

[Mad Machinist]

Ok, bringing this one back to the front again as I have a better idea of where to take this.

A 120 gal propane tank is 24" in diameter on the O.D. A 330 gal tank is 30" on the O.D. Now there are pipe flanges available to be welded on these. There are also blind flanges available for the end plates. With a little machining at your local job shop, the blind flanges could very easily be set up to hold a "trunion" for the bearings.

As for the "wear plates", these scrap propane tanks have a shell .321" thick and can be bought for next to nothing. They won't last like a manganese steel liner but you won't running 24/7 at 80 tons an hour like we do at work and you won't have the cost either.

The Allis Chalmers ball mills from back in the day used both composite rubber and high carbon steel liners so I am thinking that if one wanted, the tread off of used tires would work as a wear liner too. Bolt some high carbon steel lift bars in with carriage head bolts or mill some slots in the lift bars and trim two sides of a grade 8 bolts to form a T-bolt and away we go.

The lift bars would be used to hold the "tread liners" in place.

Or on the other hand as I was saying about the "propane tank liners":

Cut another propane tank into strips and use the lift bars to hold them in place by the lift bar clamping down on the edges.

Like I said, scrap propane tanks are cheap and they CAN be safely cut up by flooding the tanks with nitrogen or argon for the first cut. Once the first cut is done, the explosion hazard is gone. Alternatively, they can be filled with water if you don't have the inert gases available, it is just ALOT messier.

 

[SaltwaterServr]

I was just going to have a 1/4" piece of 4x8 plate rolled and welded into a cylinder would give us a 30" diameter. Slice an inch or two (to be calculated precisely) off another sheet, roll it, and it'll nest inside the outer shell. Use pass through carriage bolts to hold the inner shell in place with rubber gaskets and it'll be water tight. When the inner wears out, unbolt the outer cylinder from the flanges, knock out the inner, and slide in a new one.

That said, I had planned to go rod mill versus ball mill.

 

[Mad Machinist]

Last I checked, a 4'x8' sheet of 1/4" inch was around $300, plus the cost of having it rolled. Here's some prices on salvage propane tanks. These are about average and the place local to me wants $100 for a salvage 250 gallon.

Salvage Tanks | BLT Tanks

Some places may have them already cut so they cannot hold pressure again.

 

[SaltwaterServr]

Last I checked, a 4'x8' sheet of 1/4" inch was around $300, plus the cost of having it rolled. Here's some prices on salvage propane tanks. These are about average and the place local to me wants $100 for a salvage 250 gallon.

Salvage Tanks | BLT Tanks

Some places may have them already cut so they cannot hold pressure again.

I've worked steel for Dad since the day I turned 18. Learned to weld around 14 or so. This is the first time in my 42 years that I knew what a sheet of 1/4" 4x8 cost. I always just went and picked up whatever I needed from the stuff we had at the farm. Too dang bad it is a 2000 mile round trip.

I'm gonna be really damn attentive to your metal working ideas from here on out for sure.

 

[Mad Machinist]

I hear you on the 2000 mile round trip. Mine is 4500 round trip.

I know what metal prices are now and it is ridiculous since we have been flooded with imports. I remember when I could buy a 4'x8' sheet of AMERICAN made 1/4" steel for $100.

Here's another good one for ya. Most people hit some place like Home Depot for MIG welding wire at $80 for a ten pound spool. If ya save a little longer and buy a little bigger 220 volt MIG, you can get a 25 pound spool of MIG wire at your local welding supply place for just over $100. Tractor Supply usually has good deals on the Hobart line (made by Miller in the same factory). It will last longer and be a lot less frustrating to use as there is a more room for operator error on the 220 volt versus the 110 volt machines.

I used to drive my wife nuts with my "scrap pile of metal" until she realized what some of this stuff costs. To this day, I still run around the desert picking up the scrap metal people throw out.

 

[SaltwaterServr]

I don't buy a single thing related to metal working at a box store. I did pick up a 4' piece .25" 2x2 angle one day at a Home Depot without looking at the price. I about hit the floor when it rang up. IIRC it was just a dollar or two less than a full 40' stick.

I haven't picked up a welding machine yet but I did just now look at the Hobart line. For the price, this is hard to beat right here:

Hobart Champion 145 Welder/Generator - For Life Out Here

 

[Mad Machinist]

Not a bad little welder. If in your travels you happen to find a Lincoln SA200 or SA300, grab it. If it needs rebuilt, pay to rebuild it. You can sell those welders for a hell of a lot more than you would pay for it plus the cost of the rebuild. Get a couple of pipeline guys together and you'll have your own UFC style fight in your front yard over it.

Might have to make a trip down that way.

trailer and miller gas welder

Decent little set up. Hard rock mine in a trailer.

 

[SaltwaterServr]

Not a bad little welder. If in your travels you happen to find a Lincoln SA200 or SA300, grab it. If it needs rebuilt, pay to rebuild it. You can sell those welders for a hell of a lot more than you would pay for it plus the cost of the rebuild. Get a couple of pipeline guys together and you'll have your own UFC style fight in your front yard over it.

Might have to make a trip down that way.

trailer and miller gas welder

Decent little set up. Hard rock mine in a trailer.

I bet Dad's company had 15-20 of those 200 and 300's at the main office in San Antonio. They probably got shipped to Houston once we moved manufacturing to Mexico after he retired.

That is a dang nice little trailer there, now ain't it? For $2K no less

 

[SaltwaterServr]

Question now that I'm thinking about it again, how much material are you estimating you'll run with the ball mill you're looking to build? Weekend hobby kinds of runs or actually building up to go into mining for all your own? From what I'm gathering, you're looking to be your own boss at the end of the day.

 

[Mad Machinist]

Question now that I'm thinking about it again, how much material are you estimating you'll run with the ball mill you're looking to build? Weekend hobby kinds of runs or actually building up to go into mining for all your own? From what I'm gathering, you're looking to be your own boss at the end of the day.

Not sure on the material. Probably 1-2 tons an hour on the weekends for me. I am trying to set it up for continuous production as that is actually easier on the liners. 75% of the wear on ball mill liners comes from an empty startup or a grind out for shut down. That's when you basically have steel beating on steel. Not a pretty sight.

I actually ran my own exploration company part time on the side. Had my own core rig and a lot of ancillary equipment that was dissolved and liquidated due to a disagreement with my so called partners at the time.

I would either stake or buy claims and then core drill them to prove a resource to sell or lease it to the highest bidder. Made a lot of money doing that, more than enough to retire right now at 41. Funny thing about it is the fact that after the bills were paid, we split everything equally. I have my share, they blew their shares and accused me of stealing. This time around I sit in an office and yell at people. No more getting down and dirty with the crew when they need help. No more partners either, just employees who can be fired.

I would have liked to mine a few of the ones I cored but there is absolutely no reasonably priced equipment out there. I refuse to pay $20K for a beat to crap 4' diameter ball mill that would need at least another $40K in refurb to make it operational. Same thing with Sub "A" flotation cells. Most want more for old equipment now than it cost new back when it was new.

So now I'll use every bit of skill and knowledge that I have to fid a way for the small miner to build the equipment they need to PROFITABLY mine small pockets of minerals.

 

[Mad Machinist]

I'm sorry ladies and gentlemen, I beat this around worse than a rented mule. I've been on the phone with people from Motion Industries, Kaman, SKF, and a whole host of other ones.

There is no other way to do this any cheaper as far as the bearings are concerned. The radial loads are just too high for anything like casters or such. This is as cheap and as simple as it gets and about as small as one could go on the bearings. Hold on to your hats:

http://www.ebay.com/itm/Royersford-...0400?hash=item1a193457a0:g:IbcAAOSwQTVV9uP O

If you think this is bad, then you DON'T want to know what it would cost to do a ball bearing set up. Even if I could get you all my prices, it would still cause a few myocardial infarctions.

These do have an upside though. The lubrication is dirt simple. No muss, no fuss. Pull the pipe plug at the top and:

 

[SaltwaterServr]

I'm sorry ladies and gentlemen, I beat this around worse than a rented mule. I've been on the phone with people from Motion Industries, Kaman, SKF, and a whole host of other ones.

There is no other way to do this any cheaper as far as the bearings are concerned. The radial loads are just too high for anything like casters or such. This is as cheap and as simple as it gets and about as small as one could go on the bearings. Hold on to your hats:

http://www.ebay.com/itm/Royersford-...0400?hash=item1a193457a0:g:IbcAAOSwQTVV9uP O

If you think this is bad, then you DON'T want to know what it would cost to do a ball bearing set up. Even if I could get you all my prices, it would still cause a few myocardial infarctions.

These do have an upside though. The lubrication is dirt simple. No muss, no fuss. Pull the pipe plug at the top and:

My limited knowledge working with Baldor/Dodge is anything 3" plus is going to set you back a good used truck. We used to keep those monsters locked up in the parts department at Dad's shop for our really large ship loading/unloading and rail loading conveyor systems. Someone in that ebay company really doesn't like New Yorkers.

 

[Mad Machinist]

My limited knowledge working with Baldor/Dodge is anything 3" plus is going to set you back a good used truck. We used to keep those monsters locked up in the parts department at Dad's shop for our really large ship loading/unloading and rail loading conveyor systems. Someone in that ebay company really doesn't like New Yorkers.

Babbitt material contains small amounts of lead. And we know how they feel about lead.

They make your standard heavy duty type pillow blocks up to six inches at the low, low price of $3200 a piece. After that, your pretty much stuck with going the split housing route and that is when it gets real expensive real fast.

The link form Royersford also has a bronze type shell bearing listed. If it burns up, just pop it out and replace it like you would a rod bearing in a motor. And the radial load capacity with the bronze shell bearing is around 15,000 lbs. each. Way more than we would need, but the added capacity just means it would take severe service much better.

 

[solarsmith]

i have made one just like it a 100 lb tank and 1.1 lb ball from a wrought iron fence supply. My biggest problem is the noise over 100 db at 4 ft. im going to try to wrap the tank with rubber floor mats . I welded the small spare tires to the ends and they ride on garage door rods one side idles and the other side drives . I can do about 300 lbs an hr maby more. and get 80% passing 200 mesh witch is perfect because the 20% does not contain gold. Bryan In Denver Colorado