# Homemade Ball Mill



## Anonymous

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## Irons

Parting gift? Are they coming to take you away?


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## Barren Realms 007

I saw that when you posted it the last time. I like that one a lot.

What is this parting gift?


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## Anonymous

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## pinman

gustavus said:


> Irons said:
> 
> 
> 
> Parting gift? Are they coming to take you away?
> 
> 
> 
> 
> Those of us that are mentally handicapped are very fortunate, in Canada they let us roam free.
Click to expand...

 

Haha!


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## hemicuda

I am wondering if you could post a door picture of your ball mill,I am planning on building one as well (hopefully soon) I need to mush up some of my goodies!

Thank-you in advance,
Keith.


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## Anonymous

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## hemicuda

Thanks for the pictures straight forward and to the point! I will now have to go and have a chat with my old boss he owns a scrapyard in Kamloops,and get some material from him to build a smaller version.
I will be going down to Vancouver in the spring ( Mid March or April ).....eeeeep lol there will probably be snow up there still at that time of year.
I have never actually been to the mine itself soooooo...

I do know of the Savona used mill equipment yard, I go past there at least 3 times a year,and i was actually on thier web site the other day! Yeah i do agree with you about that bridge deck up there,they actually did finish it here a while ago nicely paved and smooth now.

Are you planning on setting up your new shop this year?


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## samuel-a

gustavus, really nice job.

i'm thinking of building one myself .

can you tell me about the noise a machine like that produce?
it look's like somthing like this will disrupt a residential neighborhood...


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## Barren Realms 007

It's really not as loud as you would think. It depends on what thicknes of tank you use a thicker tank will make less noise. And if you run it barely full charge verses a small charge the crushung media will hit the barrell more and make more noise. 

If it is a concern you can wrap the tank in foam as a sound dampener or you can build a box around the assembly to keep the noise contained.


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## samuel-a

Barren Realms 007, thank you for the info.
i taught about a foam coating, especially with regular drum which is quiet thin.

i had an idea of making a mill with no balls, but with a spinning chains in the middle at around 5K-10K rpm.
i'll finish the sckech in a few days and upload for brain storming...


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## Noxx

Nicely done !


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## Barren Realms 007

samuel-a said:


> i had an idea of making a mill with no balls, but with a spinning chains in the middle at around 5K-10K rpm.
> i'll finish the sckech in a few days and upload for brain storming...



You are talking around the lines of a hammer mill. Not as good of an idea as a ball mill IMHO. Your spinning chins will not have as much positive result as a ball mill. They will also create air turbulance in the drum and the smaller the particals the more they will want to float in the chamber rather than getting hit by the chains, the air will also find any small hole it can to get out ofthe tank along with your material. You will also have to make sure that the shaft and chain mecanisim is perfectly balanced, or it will toss the machine all over the place. A ball mill is easier to build, a lot less cost and mainteneance.

Imagine one of those chins coming off at 5,000 rpm. That can be a lot of force moving aound. And a chin reaction or\f the unbalancing and every thing desentagradeing.

You will have 100 times the noise volume as well.


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## Anonymous

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## Anonymous

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## Barren Realms 007

Under those conditions and material I can see it's use. I was just campareing it to the material you had in the bucket and him trying to produce something like that with one. If I'm correct that hammer mill you have contains metal slabs that are mounted to the shaft. There is more control over something like that than with chins. I used a hammer mill for 4-5 yrs it had a 16 wide mouth. Man you can run some material thru something like that. Your screen choice can make you or break you.


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## Anonymous

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## erogers36

i find this thread interesting, but being a newbee i'm asking myself whats the next step with the gray powder he's holding in his hands..or the process used next.


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## samuel-a

thank you guys for the insights about the mill.

erogers36 , i guess his powder was black IC's that ware incinirated, but as with other gold bearing components, the methodology remains the same, removing base metals before dissolving any values, therfor i belive next step is HCL leech or nitric leech.


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## Anonymous

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## Barren Realms 007

gustavus said:


> The drum for the ball mill I built is a discard from the oil and gas industry which I picked up at the scrap yard, the diameter is 16 inches and has a 3/8" inch wall thickness. The drum turns at 15 rpm, it take 2 hours to crush IC's into a fine powder. The motor used is 1/3 hp from an old blower motor running 3450 rpm
> 
> Using a motor that ran 1725 RPM would turn the drum half again slower than it does now,and would work but take twice the time to crush your IC's into powder.
> 
> The simplest form of ball mill drive would be to use a chain wrapped around the drum, welding a sprocket tooth every 3 or 4 inches, the end result would be a very large sprocket, and would also keep the weight down.
> 
> To align and space each tooth before welding use the chain for a pitch guide. You may have to cut the teeth from a sprocket but this is going to be far more economical for you than buying a sprocket that large.
> 
> For the motor end Browning makes semi finished blanks, both in gear and chain sprocket stock with an assortment of couplers and bushings, kind of an adults Mechano set
> 
> Belts may work, but remember a charged drum is going to be very heavy and belts have a tendency to slip, your best bet would be using a serpentine belt such as used on most automobiles of the last 20 or more years.
> 
> The first ball mill I built use a 5 HP DC motor directly coupled to the end of the drum, similar to what I have done with the latest mill. The beauty of the DC motor was that you could electronically control the RPM. I have one DC motor left that is going on my drill new drill press.




How many lbs of chips was in that batch that took 2 hrs?

The current motor you are using must have come out of a commercial blower. That 1750 RPM motor you could adjust the pully size. What kind of gear box was that on your's and do you know what it came off of?


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## Anonymous

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## pinman

Would the balls from old computer mice be suitable in a small ball mill? 5 gallon capacity.


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## 4metals

Considering how light a computer mouse is how much can the ball weigh? Your goal is to crush the material not caress it. Balls in a ball mill need to be heavy.


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## Barren Realms 007

You don't have to use balls. You can use steel bolts, pipe nipples with caps on them(you can pour lead in them to make them heavier).


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## leavemealone

Barren, I would not suggest pouring lead inside unless it is completly encased in grade 8 material.That includes making sure the nuts and bolts are grade 8 also.It was mentioned on another post about the softer metals also wearing down and you will be left with Fe contaminents.Grade 8 is hard enough where that shouldn't be a problem.

Gustavus,I am curious what you used to incinerate that much material at once.I use my kiln 2200F or my furnace 3000F but I can only run a few pounds at a time.
Johnny


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## pinman

Barren Realms 007 said:


> You don't have to use balls. You can use steel bolts, pipe nipples with caps on them(you can pour lead in them to make them heavier).



Good to know I was under the impression they had to be made of a specific material. Thank you.


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## pinman

I was in the middleof posting when leavemealone mentioned grade 8 material. Is there a way to determine it's grade by sight?


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## qst42know

http://www.rockcrawler.com/techreports/fasteners/index.asp


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## Barren Realms 007

leavemealone said:


> Barren, I would not suggest pouring lead inside unless it is completly encased in grade 8 material.That includes making sure the nuts and bolts are grade 8 also.It was mentioned on another post about the softer metals also wearing down and you will be left with Fe contaminents.Grade 8 is hard enough where that shouldn't be a problem.
> 
> Gustavus,I am curious what you used to incinerate that much material at once.I use my kiln 2200F or my furnace 3000F but I can only run a few pounds at a time.
> Johnny



I agree Johnny but some might not have access to these types of metals. I have about 4-5 5 gal buckets of wheel studs that I can use. I have a lot of pipe I can cut and thread and cap to use, not the best item I agree but some have no other choice. I have hundreds of lbs of lead I need to use some where. One of these days I'm going to have to post some pictures of my shop.


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## pinman

qst42know said:


> http://www.rockcrawler.com/techreports/fasteners/index.asp





Good link thank you.


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## leavemealone

> I agree Johnny but some might not have access to these types of metals.


Absolutely.If you (or anyone else) has no access or cannot afford grade 8 it's not that big of a deal.Simply make sure you check your material using a strong magnet.There are numerous methods for doing that here on the forum.
This entire forum is about accomplishing things with what we have available.In this case it's ok because the magnet will seperate the Fe.
I am fortunate enough to have access to pretty much anything here,and I tend to forget that when dealing with the members on the forums.Sorry about that.
Johnny


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## Anonymous

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## pinman

I have 1/2" x 2" long grade8 bolts how many do I use Ina 5gallon mill?


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## 4metals

The down side to using bolts is the ball mills that do not have dump doors and dust enclosures require you to dump the charge and the crushing media together. Then you have to clean the crushed powder off the media. I can imagine the threads becoming packed with crushed material and needing to be cleaned.

Time consuming, however use what you have, fill the mill half way with media.


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## Anonymous

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## Anonymous

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## Barren Realms 007

Man ya'll are tough on a guys ideas today :roll: .

I'm going to go put my dunce hat back on and sit in my corner.


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## 4metals

Not true 007

If you have a ball mill with a dump door and a dust enclosure, you tumble the charge with whatever heavy medium you have then stop the mill, change the door to a dump door, which has holes in it, and run the mill. The dust falls out into a tray, the dust enclosure keeps all of the dust inside, and the media cleans itself. Now bolts will take longer than balls to self clean but it is do-able. 

If you ball mill every day, multiple loads a dumping mill with a dust enclosure is the only way to go.


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## Anonymous

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## leavemealone

> Grade 8 will work but are going to wear quickly adding garbage


I must have read it wrong then.I thought one member had mentioned that grade 8 was hard enough.I probably read it backwards though,after reading about 100 posts a day my eyes start crossing... :roll: 
Johnny


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## Barren Realms 007

gustavus said:


> Barren Realms 007 said:
> 
> 
> 
> Man ya'll are tough on a guys ideas today :roll: .
> 
> I'm going to go put my dunce hat back on and sit in my corner.
> 
> 
> 
> 
> These worthless ideas could go on for pages and pages, and more worthless pages of drivel. You want to accommodate that type of dialog, you can not build a ball mill inside this forum.
> 
> Perhaps I should have included a list of the required shop tools one would need to build such a mill.
> 
> 1. A cloths dryer is not going to make the grade
> 2. For all the good mice balls would do, you could just as well fill the drum with paper clips.
> 3. A basic understanding of electricity.
> 4. If your skin is so thin, move along.
Click to expand...


Hold on sir it was a joke. I didn't mean for you to take it serious. I said the dryer wouldn't work, didn't comment on the mice balls and still won't :roll: . I have a Master electrical license. My skin is not real thin either. I liked your ball mill, only question I asked about it was the gear box I think. and a comment about the motor. And btw you probably will not find a motor in a residential HVAC unit that runs over 3,000 RPM most run around 1750 RPM or slower with a few exceptions, I have a master HVAC lic as well. I don't mean to question your abilities your photos show your ability for them selves and they are good. I enjoy your posts.


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## Anonymous

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## butcher

I think Gustavus, is just trying to get you to see that this needs a little more serious thought, a dryer is good to tumble clothes, a ball mill would need to be much stronger to do the job.

a tack hammer won't work if you need a sledge hammer to get the job done, look at the ball mill in the picture above, built from used junk,built well and strong, and the handful of fine dust proved it works, now that type of thinking is what you need to build a simple ball mill, forget the dryer or plastic 5 gallon bucket, if that is all you can come up with, get you a piece of 2"pipe say 12" long and a cap, then a 1" pipe 18" long with a cap on each end, crush your material with that untill you can come up with a better Idea.


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## pinman

I only asked about the mice because they have a 1/2" ball bearing beneath the rubber. Sorry to have stirred up such a stink.


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## Anonymous

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## Barren Realms 007

gustavus said:


> I'm 60 years old and find very little amusing, I thought the forum was an educational site where one could learn from reading then move on to practical, run into a problem there is help from the more experienced. Between the resident Pro's we have at our disposal my estimate 300 years of experience at our disposal - all for free.
> 
> The resident professional refiners have dedicated many hours answering our questions, sometimes , many times replying to the same questions written a bit differently from the last guy.



I agree the pro's do a great job and this forum would be nowhere without them. I really don't know how they do it day in and day out answering the same questions. I would like to think that you are included in this list because of your abilities and vast knowledge as well as your experience in diffrent fields.

I really didn't mean for this to get blown out of proportion about using a dryer. I thought it would have been dropped after my 1st reply but it wasn't and it has snowballed into a tense situation. I normally would have written a short answer and say this would not be a good idea and list the reasons why, I didn't do that I was being a smart ass and answered with a smart answer. Well it has gotten blown out of proportion and caused a wrinkle in a possability of a friendship developed betwen us and I really don't want that to happen. I would like to feel that I can ask you question and I know I will receive a mature and accurate answer that can be properly applied to the situation at hand



> If you got up each morning and all you read were the comic section and cartoons on the box, what an interesting person you would be. Have some mercy and respect for the Professionals donating their expert knowledge and time.



I really don't have enough of a sense of humor to get much out of reading the comics on a daily basis. It seems like that is what it is like here sometimes (reading the comics). I have all the respect in the world for the leaders, the knowledge they share here and thier time that is sacrificed answering the same things over and over.



> I would think that the Pro's have a rather high IQ level and here we are boring them to death, lets us try to keep their minds busy at work with intelligent questions
> 
> A good wine is known to mature with age, this forum has aged but not matured.



This is true, they shuld not be botherd with having deal with questions off in left field.



> If a guy is not able to at least change the spark plugs in his automobile, he should not be attempting to build a ball mill.



That a 100% corrct answer, someone with the lack of abilities to do such things are bound to get hurt or hurt other people and they should not be attempting to work with these chemicals. They can bee to dangerous.



> On a side note, the spelling from a couple of our members not naming anyone in particular is atrocious, MINE INCLUDED. I use firefox with a spellcheck every wrongly spelled word is underlined in a red drawing my attention towards it to make a correction, check the spelling then add to the dictionary.
> 
> If I'm not sure of the spelling of a word, I google it then copy and paste the correction into my post. You have probably heard that a lot of good deals can be found on ebay because some guy/gal cant spell worth a darn.
> 
> Perhaps I'm taking the spelling thing a bit far, but it relates to having _respect _for the Pro's donating their time.
> 
> People who repeatedly asks STUPID QUESTIONS should be directed to the lounge.
> 
> Sincerely Gill



I can admit that my spelling and grammer are not the best as well. It is not something I put a high reguard on I will try to do better in this area. It is not ment as a insult to anyone.




> Barren Realms 007 a man of your caliber, several trade TQ's.
> 
> I'll bet you an ounce of gold, anyone who asks you how to fix their washing machine and comes on with absolutely no knowledge in asking the questions gets short listed real quick.



I would say that is not completely true, If someone asks a question and they are sincere on learning the answers I will walk them thru fixing the problem as best I can in a step by step way to acomplish the task. I enjoy teaching people that want to learn and have little paitence for people that want to take short cuts and not follow instructions.



> So why do we have to entertain and encourage such nonsense by answering dumb questions, where others as or less knowledgeable jump in keeping the thread alive. This is the drivel I'm speaking of, and I can not for the life of me see how that would be entertaining or stimulating to a learned friend who has put in many years dues inthe art of refining.



You know as well as I do that there are going to be people that post stupid question's and some more than once about the same thing. I don't care for it any more than you do but it is going to happen. I'm sure most of the pros here just shake thire haeds and wonder where people come up with some of the off the wall ideas but they tolerate it and carry on. That is dedication and integrity that is beyond approach.



> It just never stops, had you tired that in trade school they would have written you a ticket alright, one back home. We have to give the Pro's what is rightfully due them, some respect in the type of questions we reply to keeping that thread alive until a questions has been properly answered or a problem resolved.



The teachers did come close a couple of times I think. I use to press the teachers on scinerios that were way out there, that was because I had been in the fields for a lot of time and liked messing with them. And generally knew they would not come up with a correct answer because of thier lack of experience.

Again let me offer my aplologies to you. I really wasn't trying to question you, your abilities or your judgement. And I didn't mean to have this get blown out of proportion. I offer my hand to you for a hand sake to show my sincerity, I hope we can let this be forgotten and ended and be friends.


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## Anonymous

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## Barren Realms 007

I agree with your above post 100%. I say we put a fork in it call it done and continue as friends.

We have all had our time of mis spent youth. Any one that can rise above that and make something of themselves is A-1 in my book.


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## butcher

been a long winter, we all need some sunshine. :lol:


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## erogers36

Will 5 of these work for a ball mill ?


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## leavemealone

Wow eric,thats a hell of an idea.I have a bunch of those and I have a chop saw that can cut the shafts off.
Gill do you think these would be hard enough to not wear down fast?
Johnny


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## Anonymous

leavemealone said:


> Wow eric,thats a hell of an idea.I have a bunch of those and I have a chop saw that can cut the shafts off.
> Gill do you think these would be hard enough to not wear down fast?
> Johnny



Not sure about the cheap chrome plating which is going to eventually peel off, otherwise they would be perfect for the hobby refiner. Ideally if you could get your hands on some cat or excavator track chains and cut the link to suit. The metal used for crushing does not have to be round like a ball, just heavy and wear resistant.


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## leavemealone

The father of one of my friends owns a large trackhoe maybe I'll see if he has any parts of the track that is useless to him.You will have to show me what part to use though.If I get anything from him I'll post a pic and let you decide.Thanks gil
Johnny


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## Anonymous

Here's a picture of some track chain, you could also use the the old bolts and nuts used to hold the pads in place also the old pads cut up into smaller pieces, all these parts are highly resistant to wear.


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## Barren Realms 007

gustavus said:


> you could also use the the old bolts and nuts .



I mentioned useing this earlier in this thread and people didn't like the idea.


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## Anonymous

Barren Realms 007 said:


> gustavus said:
> 
> 
> 
> you could also use the the old bolts and nuts .
> 
> 
> 
> 
> I mentioned useing this earlier in this thread and people didn't like the idea.
Click to expand...


Difference is Cat bolts are Fedalloy which are superior to grade 8


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## Barren Realms 007

gustavus said:


> Barren Realms 007 said:
> 
> 
> 
> 
> 
> gustavus said:
> 
> 
> 
> you could also use the the old bolts and nuts .
> 
> 
> 
> 
> I mentioned useing this earlier in this thread and people didn't like the idea.
> 
> Click to expand...
> 
> 
> Difference is Cat bolts are Fedalloy which are superior to grade 8
Click to expand...


Ok thanks. :mrgreen: Always a learning experience.


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## samuel-a

hi guys.

i have done some research on the web, which lead me to conclude that the bigger & heavier grinding media isn't always better.
particularly when grinding ceramics or fibrous matirial.

a study that i stumbled across on the web suggest that 1/2" to 5/8" balls as grinding media preform the best for... basiclly most of ball mills, regardless of their size and matter to be grinded. assuming that the mill is running on it's optimum RPM.

now, the only way i know of, to get that kind of steel balls are from bearings, but i do not know how they will preform over time as they are designed to wear and not to impact. (any suggestions?)

the optimum RPM for any given size of mill is 65%-75% of it's 'criticl speed' 
critical speed = the speed of which the cylinder becomes a centrifuge.

i'm currently working on the construction of 3.5 gallon mill from 8.5" steel pipe.
i'll update with pics when ready.


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## skippy

Ball bearings are usually 52100 steel, a high carbon steel. Looking it up, they are hardened to 59 Rockwell C hardness, which is just a little less hard than a file. 

Now I'm looking up grinding media, and these specs come up

► Chrome or chromium alloy steel.
AISI 52100 / SUJ 2 / En 31.

► High carbon steel.
AISI 1085 / C85.

Thorough hardened to 58 - 63 HRc,
Rockwell C.

So basically ball bearings are already nearly perfect grinding media. 8)


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## Harold_V

samuel-a said:


> a study that i stumbled across on the web suggest that 1/2" to 5/8" balls as grinding media preform the best for... basiclly most of ball mills, regardless of their size and matter to be grinded. assuming that the mill is running on it's optimum RPM.


 I suggest you research further. Large objects, such as extremely large pieces of ore, do not respond well to small balls. It is also well known that ball mills start with much larger balls, often as large as 6" in diameter, and have them replaced when they abrade to smaller sizes. It takes a given amount of energy to reduce the size of large objects efficiently----energy that simply isn't provided by small balls. 

I would agree with your assessment, assuming the feed was small in the beginning--perhaps 1/8"-. 

From personal experience----I ran my ball mill with balls that ranged from 3/4" up to 2" diameter, plus a percentage of old rollers, roughly 3/4" diameter and 1" long. Ore pieces larger than 3/4" were broken down by attrition only. A piece of gold bearing quartz roughly 1½" in size ran in the mill for days before it was reduced. My mill was something like 18" in diameter, and operated at the precise speed advised for the size. The feed I processed was sized 1/2"-, as I recall. 

Harold


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## samuel-a

skippy - thank you for the info, this is really helpful.

Harold - that kind of personal expirience is rare, i couldn't agree more about large pieces of ore or extremely hard matirial. it does make sense.
what ball size would you recommand if i'm to feed the mill only with processors, flat packs and quad black IC's ?
a mix of 1/2" - 5/8" looks sufficient for that task?

anuther question, when job is done, how did you seperated the balls from the fine powder? simple screen?

thanks


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## Harold_V

samuel-a said:


> skippy - thank you for the info, this is really helpful.
> 
> Harold - that kind of personal expirience is rare, i couldn't agree more about large pieces of ore or extremely hard matirial. it does make sense.
> what ball size would you recommand if i'm to feed the mill only with processors, flat packs and quad black IC's ?
> a mix of 1/2" - 5/8" looks sufficient for that task?


A gut feeling says no, it's not sufficient. The material from which they are made is very hard and tough. I'd suggest you would need at least 1" balls, and maybe larger. The shorter the distance the balls fall, the larger will be the requirement, too. I'm basing my opinion on the ball mill I built, which was about 18" in diameter. You may find that you require balls at least 2" in diameter in order to crush instead of abrade the feedstock. It's important that the balls crush----not just abrade. 



> anuther question, when job is done, how did you seperated the balls from the fine powder? simple screen?


if you build a batch mill, I have no clue. My ball mill was a constant feed, constant discharge, and was operated wet. Nothing large was able to escape the mill, and little that required further crushing was discharged. The discharge from my mill was transferred directly to a fine mesh stainless screen, with the small amount that didn't clear the screen simply added to the feedstock to be reprocessed. Discharge on my mill could be easily controlled by the volume of water that was added. The smaller the addition, the longer material remained in the mill before being discharged. 

Harold


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## 4metals

> how did you seperated the balls from the fine powder? simple screen?



Most batch ball mills are dumped by removing the crushing door and putting on the dump door. Of course you will need to have a dust enclosure over the mill to collect the cloud of fine dust dropping from the holes in the dump door. Most enclosures have a drawer for the dust to collect in.


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