fwiw - rod-mill project start

Early stage "blagging" materials, and thoughts leading there.

Someone I know has a "stash" of good-assay tin ore. Plus other ores might be obtained.

Regards, Rich S

--------------------------------------- A hydraulic cylinder rebuilder may be a source of used or cutoffs of case-hardened steel rod, cylinders and end caps. The rods could be either hard chromed or nitrided, the used rods pitted and cylinders internally scratched.

The only cost to me was pretending to appreciate the owner's extensive cell phone photo album after I showed him pix of what I was building to prove my credibility.

Early stage "blagging" materials, and thoughts leading there.

Someone I know has a "stash" of good-assay tin ore. Plus other ores might be obtained.

Regards, Rich S

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Why is a rolling mill better than a stamping mill? Is it better?

I only ask, because many years ago a friend of my dad's had a lode claim (gold) with a pretty good assay, but it was all very fine wire and lens throughout the rock. They talked about the fact that they would have to haul basically unsorted raw ore several miles to set up a stamping plant due to proximity around the claim of a wildlife preserve and a military reservation. Looking at what you have there it seems like a rolling mill could be quite small compared to the sort of stamping plant they were talking about. I always wondered why they couldn't crush and partially sort on site. It was ultra fine gold though. You could pick up a rock the size of your fist and see tiny little glints all over it.

I don't know who holds that claim today, but at to day's price of gold I wouldn't be surprised if somebody who knows about the location isn't out there working it or jumping it. Gold was over $3000 spot as of yesterday when I was in a local buyer's office. I sold some silver yesterday. Not going to say what the assay numbers were, because I could misremember, its high and might incite rogues, and they could have been exaggerating to try and entice investors.

Thanks for hint. There's a lot of marine engineering around here - could be source of unserviceable rams, etc.

Thanks - I didn't spot this. "vanning" is what we are supposed to be doing - what I should be shown - when we do a small ore run "manually". I've seen videos of vanning at the nearby King Edward Mine museum - which is "the mill" kept by the Camborne School of Mines for tuition which had served the nearby mines. Vanning shovels "do exist" here in Cornwall...

Will return to it - very informative. Must search more of "911metallurgist" site.

BTW I loved when "911metallurgist" sent Dan Hurd - he has a Youtube channel and lives just over the border from you near the Fraser River in British Columbia - a "beautiful" laboratory for-samples jaw crusher. All nicely painted, chromed flywheel, etc. Dan Hurd is a prospector "through-and-through". Well, I can work out what "911metallurgist" was doing - if it could survive Dan Hurd's idea(s) of "giving it a try" on his prospecting mineral samples, anyone would know this machine is "the real deal". There it was, all shiny and chromed, with Dan Hurd dropping in samples of his "best rocks" - really notoriously hard ones which are problematic for crushers in general - going way up the scale where he was eulogising about how "excellent" these rocks were. He'd got the motor he'd rigged-up to it stalling-out with the resistance to crushing these "special samples" had, and so on. Have to laugh thinking of it. So yes - "911metallurgist" - knows what's what and who's who :-) Here it is "Jaw Crusher (Testing the 911MPE.com Jaw crusher with HARD rocks)" Dan Hurd (Dan Hurd Prospecting) "In this video I put the 911 Metallurgist Jaw crusher to the test and feed it the hardest rocks around trying to stall it or break it. it takes everything I can throw at it and survives."

Huge caveat

• I am sub-novice at mineral processing * !!!

I am *looking forward to* using a hammer and plate, then a vanning shovel, to separate black tin from know excellent ore, to put it in perspective.

There are rolls - which are a bit specialist - a nip angle which will grip means big rolls for small max. feed size and small reduction ratio.

Look up "rod-mill". They are usually bbiiiggggg!!! They come between the crushing stage - usually primary and secondary - and the fine-grinding stages. For an "artisan" mine - a size big enough to break up the run-of-mine ore would be a behemoth with a tonnes/hour which would swallow the year's production in minutes - infeasible. Grinding is usually done wet. Desert? Water scarce/expensive? Stamp mills are also usually used/done wet (?)

Taking it you've got to work "dry"... Grizzlies and sledgehammer (or dynamite) to break up rocks to manageable "feed size"

Crusher - likely jaw crusher. Small/manageable given feed passes through a grizzly. Even if can't separate at the mine, gives a dense self-packing load to transport.

Okay - I can see where this is heading... Every form of separation needs water... This is desert? Might be a reason which forces transporting the crushed no-separation run-of-mine ore.

I doubt the ore could be "overground" - so ball-mill "a lot", but could "pancake" the gold particles and make the likes of shaker-tables (need water!) less effective. So grind you could at the mine - but it doesn't get you anywhere if you can't separate there.

Then - all these considerations - where gold is very fine, this tends to send you to cyanide heap leeching. Okay now you need some water and you have to contain cyanide. Then even if you keep the same fluid circulating you need a cyanide destructor, which I understand uses a lot of hydrogen peroxide. So again, lot of transport on that alone.

I can't see where all this is going, apart from - I bet there were a lot of folk very knowledgeable and experienced processing gold, and they couldn't come up with any better than transporting the run-of-mine ore to a place with water, electricity, etc. As I said, my instinct is put it through a primary and maybe secondary crusher, which is done "dry" - so no problem of water to the mine if in a desert - to make the ore fine so it pours densely into containers, for transport.

Hope I've done more good than harm

Rich S.

------------------------------------- I don't remember if this ever came up, so here it is (again?).

Steel wire screen chips away the edge of broken glass fairly rapidly when swiped quickly across it, to shape it into a replacement for an old gauge for instance.

I haven't found which old book he copied from.

Water is a good argument.

Many years later and no longer a child I'm also open to the possibility that it was really a salted claim intended to try to bilk investors into buying shares.

The gold samples shown were real, but I never visited that site myself. I was a kid at the time, and I have become more cynical with many years experience in business.

On the other hand there were real working gold mines in the area. Many of which were encompassed by the wildlife refuge when it was formed. I think there are still one or two continuously worked claims within the refuge which are grandfathered in access and the right to continue mining. I myself found and worked out gold from a clay bank laying on a rock shelf downstream from where a small lens (20 feet long, 3 feet across and about 3 feet deep into the remaining mountain) had been worked out in the American gold rush or shortly thereafter. The clay bank was missed by the miner that discovered the lens, and by the Chinese crews that placered the sand wash bottom below down to the bed rock.

The claim might have been legit. There was definitely gold in the area. They claimed it was to costly to transport the ore off site to process.

I also have learned a bit about the primary person staking the person who held the claim. They were a fairly successful surplus and junk dealer. The type that would make an offer to sell, see how interested you are and then raise the price. Multiple times. I tried to deal with him a couple times in later years. He had long since alienated my father for that sort of moving the goal post, and he tried the same things with me. Somebody who negotiates that way can not in my opinion be trusted. Just before he died I think he still believed my dad was his friend, but my dad was the type who said, "Who you are in business is who you are. Its never, 'just business.'" They had not been friends for a very long time. I won't say he was a cheat or a chiseler, but I found his practices to be dishonest. I know one of the things I wanted to buy from him is still sitting in the salvage yard his surviving son is trying to clear out unsold. I stopped by to chat with his son, and quickly found he was the same way. I never went back.

The odds that is was a salted claim are 50:50 in my opinion.

Sorry for the turn of this post. My initial query was sincere on the subject. Its just that upon thinking about the practicality of processing ore many things came back from my memory's deep storage.

You are very welcome, regardless.

I have heard of "salted" claims. It can be a risky thing to do. In one jurisdiction known for probity, if falling out of a helicopter is surprising, for it to deny the chance for two people to explain themselves in court is an astonishing coincidence.

A rod-mill is often the precursor to a ball-mill. A rod-mill is valued for giving a very narrow size distribution - a consideration including that it will not "over-grind" friable components within a mineral. That size is "larger" - seemingly often like sand on a beach. A ball mill can go much smaller. Taking rod-mill output as the ball-mill input gives a good "level" starting point for ball-milling.

I will leave it at that. Neither experience nor hearsay enables me to go further.

Early stage "blagging" materials, and thoughts leading there.

Someone I know has a "stash" of good-assay tin ore. Plus other ores might be obtained.

Regards, Rich S

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When considering the size of lathe you need for long cylinders you must allow for the smaller clearance under the carriage. Mine for instance will turn 10" diameter work at the spindle but only 5" diameter over the carriage.

The ends of a larger tube could possibly be squared with the carriage beyond its end, if the tailstock spindle extends far enough to reach a plug jammed into the tube and still allow a little carriage travel. It's a tricky setup.

An old worn lathe may be good enough for the sort of projects you've mentioned. Your limit of accuracy is how closely you can measure more than what the lathe gives without extra effort. If it's an unsupported oddball you really need only a faceplate and a 4 jaw chuck. The Difference Engine shows what a fairly primitive lathe is capable of.

I am not sure a lathe is necessary at all if welded together (end-plates, etc.). Well, making rollers for the "barrel" to roll on would benefit from a lathe. The idea of a rope drive, from which the name "lathe" comes from - a lath, rope and plank for the foot-pedal - is hopefully also very achievable.

I am not sure a lathe is necessary at all if welded together (end-plates, etc.). Well, making rollers for the "barrel" to roll on would benefit from a lathe. The idea of a rope drive, from which the name "lathe" comes from - a lath, rope and plank for the foot-pedal - is hopefully also very achievable.

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Before I bought a house with shop space I used my father's wood lathe to make machine parts such as pulleys and rollers. Rings sawed from scrap water pipe reinforced the hubs. Unfortunately the dimensions of water pipe don't match available bearing sizes. Fitting them to a removable press fit is necessarily a metal lathe task. Wood was adequate for hand crank, wind and water power but doesn't last long on motorized equipment.

I found that multiple turns of cotton string made a pretty reliable outdoor rope drive. I boiled the wooden pulleys in molten canning wax to weatherproof them. The wax shrinks as it solidifies and pulls in from the surface, which then isn't slippery. The knot tends to ride smoothly on the outside of the strings. A taut-line hitch adjusts the tension without needing an idler or other means.

Comment about wooden pulleys appreciated. This is considering rigs which will likely be run for a few hours only.

I pretty much had to attach the larger wooden pulleys directly to the load, such as a windmill rock tumbler drum. Without a metal lathe I couldn't make a steel flange to attach the pulley to a strong steel shaft. Water pipe and floor flanges didn't work out very well, welded-seam pipe is never quite round and standard sized bearings don't fit it. I didn't try cast lead bearings because of the pipe's irregular surface.

Hardwood end grain bearings held up for a while under light loading, they needed to be easily and frequently replaced. I used oak from flooring scraps. Lignum Vitae propeller shaft bearings are an example.

Wood and steel machine frames can be made with hand tools or a bandsaw but power transmission components may be very difficult without a lathe, especially custom shapes for uncommon uses or used / surplus parts that are available because they don't fit standard sized shafts.

Purchased parts are expensive, one 3/4" shaft, jaw coupler, steel pulley and pillow blocks for my sawmill cost as much as the new gas engine. The jaw coupler protects the engine shaft and bearings from any misalignment or frame twist from the load; shaft and bearing alignment on a weld-distorted frame can be difficult. I studied the "Audel Millwrights and Mechanics Guide."

A cheaper zinc alloy pulley from the hardware store deformed loose in other use although the shaft connection to the hydraulic pump was a custom-broached 6 spline press fit instead of the usual single key. I replaced it with a lower flow pump run faster, the same power at lower shaft torque and belt tension.

Much of the backwoods engineering I could get away with for low HP electric motors failed with higher HP gas engines, I needed to understand and stay within components' ratings.

With the lathe I can make the hub adapters and roller and ball thrust bearings I want, a pipe sized solar array thrust bearing and wet location wheels made from stainless steel pipe and rod scraps. The lathe and milling machine add precision to weldments and off-sized scrap metal and largely eliminate filing and shimming. I needed to grind, file and shim only assembles too large to machine such as the weld-warped engine mount plate on my log splitter. jsw

The point of that rambling is that I could buy a good solution at substantial expense or build an adequate one with basic machine tools, without either my attempts at rotating machinery were necessarily pre-industrial and largely made of wood, more models than practical productive machines. The fit and alignment of shafts and bearings was the main limitation. My only partial success was assembling small air compressors before relatively inexpensive imported ones became available in the 1980's.

The Holtzapffel series and "De Re Metallica" show the state and difficulties of mechanical technology before Maudslay's precision lathe revolutionized it in 1797. "English and American Tool Builders" describes the rapid progress it enabled.

Getting a lathe again might come into view, if projects take-off. A reality I need to get through is processing some ore with a bucking hammer and a bucking plate - hit and grind with a flat-faced "hammer" on a flat hard plate. Then get a "Mark 1/2" rod-mill going. If this is "sofar so good" and progressing - workshop then comes into view.

"Jim Wilkins" snipped-for-privacy@gmail.com writes: ....

Getting a lathe again might come into view, if projects take-off. A reality I need to get through is processing some ore with a bucking hammer and a bucking plate - hit and grind with a flat-faced "hammer" on a flat hard plate. Then get a "Mark 1/2" rod-mill going. If this is "sofar so good" and progressing - workshop then comes into view.

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An inexpensive rock tumbler might serve as proof-of-concept within its limits of motor torque and roller friction. Adding pulleys to drive the second roller from the first helps with friction.

You could build a larger one with keyed shafting, hardware store pulleys and heater hose rollers. They are simple and imprecise enough to use pressed-in nylon sleeve bearings.

There are a lot of mineral processing experts around here, and it is indicated that I seem to be going along a promising path. That's the point - participate. I work at a "fabco" so accumulate steels for the project - and projects are okay... A lot of my work is making parts for mineral processing machinery, so an interest in the topic fits with everything about our trading environment.

There are a lot of mineral processing experts around here, and it is indicated that I seem to be going along a promising path. That's the point - participate. I work at a "fabco" so accumulate steels for the project - and projects are okay... A lot of my work is making parts for mineral processing machinery, so an interest in the topic fits with everything about our trading environment.

------------------------------- For home projects I do a fairly rough initial design to find the minimum size of each part, such as the splice plates for the gantry beam. Then when scrap steel is available I can quickly pick suitable pieces that are large enough for the task and small enough to trim on my bandsaw. I keep 4" dial calipers and a 1/4" wide tape measure in the car and truck, both are better pocket sizes than larger ones.

The calipers were useful yesterday after buying the HF off-road jack and load spreader bar, both on sale for $100 off. The lift pad attaching bolt has a 24 x 1.5 mm thread that I couldn't match in a hardware store, they had only 24mm coarse pitch. A custom bolt for attaching other accessories could be turned from 1-1/8" rod and I have the metric threading change gears for the lathe.