Sciencemadness Discussion Board - oh my god! 2900$ for a mortar???

oh my god! 2900$ for a mortar???

pneumatician - 12-4-2021 at 16:29

I need a mortar for grind some rocks of around 7 in mohs scale and a mortar of iron is destrolled with this material! so I check to buy a mortar of Titanium and... wft!! 2900$ for this toy??? a bit expensive, no?

someone used one of titanium?? the area of impact in pestle is smooth after use with really hard rocks?? or lose some bits, is full of scraches...??

Tungsten Carbide is no good for heavy metals?

so others options "a bit" more cheap??

https://axel-search-e.as-1.co.jp/asone/global/g/NC3-7613-01/

https://www.samaterials.com/tungsten-carbide/2750-tungsten-c...

violet sin - 12-4-2021 at 18:07

That looks like a fancy lill thing ... PRICEY though.

On a more reasonable note, could you not throw a facing sheet in the bottom of something durable? A thin sheet bent up or tube sleeve for the bore length.

Kinda feel like you could beat the piss outta some hard rocks in an improvised device: section of galvie pipe nipple and end cap with a titanium disk 1/4" thick and a thin sheet sleeve. Really depends on how much material, will it be often used and such. But for a short run you may be able to cheat.

I've got two slabs of Ti( 6Al4V ) that would definitely crush stuff.. finding it would be the trick, hahahhaha.

pneumatician - 12-4-2021 at 19:17

oh yeah, good redneck idea! :-) but titanium can be welded with steel?

DraconicAcid - 12-4-2021 at 20:15

I can only see paying that much for a mortar if it's the artillary kind.

Fyndium - 12-4-2021 at 23:46

Titanium is challenging to machine and somewhat expensive as an alloy, and it also comes with huge premium being a specialty product.

You might wanna look into materials that are unreactive. Second to that, acceptable impurities should be considered, if the material is not for analytical purpose. Also, if the impurities are inert, like glass, it doesn't matter. Using too soft or unsuitable materials for small amounts and short time is usually not a problem. For example, I just pumped HCl gas through PU tube - it corrodes and is already nasty yellowish-green, but it still lasts several hours and doesn't affect the process. PU tube costs 50c per m, while PTFE cost 10€.

rockyit98 - 13-4-2021 at 00:55

try alumina mortar s .

zed - 13-4-2021 at 06:52

Ball Milling? Let the rocks, beat-up on the other rocks. That, is how time, made our beaches.

Your milling jar, can be ABS plastic. It's kinda soft, and durable. While stones are hard and brittle.

It's like a game of Rock, Paper, Scissors. The container endures, while the rocks are reduced to dust.

At some point, the addition of some Ball Bearings, might be helpful. Same principle as a Rock Tumbler.

https://www.samaterials.com/tungsten-carbide/2749-tungsten-c...

You just set things up. Pour yourself a beer, and go watch a soccer match on TV. If your rocks aren't powder when yer done, just leave things running, and go to sleep. Check again in the morning.

https://en.wikipedia.org/wiki/Ball_mill

[Edited on 13-4-2021 by zed]

[Edited on 13-4-2021 by zed]

[Edited on 13-4-2021 by zed]

Fulmen - 13-4-2021 at 07:12

Titanium would be a poor choice for a mortar. Contrary to common belief titanium isn't particularly hard. It has excellent strength-to-weight-ratio, but it's not stronger or harder than tool steel. If hardened steel won't cut it I would start looking at ceramics.

violet sin - 13-4-2021 at 10:23

@Fulmen
What about it's work hardening property. From my LIMITED experience and fair amount of reading, it gets really pissy about heat and pressure.

Look at the YouTube vids on cutting it with cold temps and single pass w/ tons of lubricant. It's said if you forge forward with too high a feed rate, it will start eating blades left and right. You can drill it as long as there's not too much dwell time. But might as well pick a new spot to drill if it f's up there (normal drill bits). Metal forums said it's hard to deal with and thick sections are ideally cut by water jet. Last time I inquired it was 30$/in to do that in california.

My stiletto hammer will beat the piss outta steel brackets and has done so for years. It's just too light to proper F them things. Really annoying when every joist hanger is low and in the way for drywall.

Perhaps the internet lies or exaggerates the facts, but it sure becomes less than profitable to blow through a whole bunch of cutting tools for something small. So maybe it's just from metal fabricators love of profits, rightfully so, that gives it such a bad name.

I've included no references, sorry. No time for that presently.

Morgan - 13-4-2021 at 10:43

That brought to mind some "pestle shapes" I bought at some industrial supply store for cheap. They were large titanium ball joints for hip replacements still in the package. The finish of course was mirror smooth and they had a long angled spike on them. They were probably an alloy though?

zed - 13-4-2021 at 10:58

Morgan, those are expensive. Very expensive. Sellable.

When my Aunt Died, they recycled her Titanium Hip transplant.

Fulmen - 13-4-2021 at 11:37

Steels can work harden too you know. The workhorse of the industry, Ti6Al4V, has an ultimate tensile strength of 950MPa. That's nothing, I can buy fasteners that are 1200Mpa at the hardware store. And tool steel can reach twice of that.

But titanium machines like crap, that's for sure. It work hardens like nothing else, and I suspect the low Youngs Modulus makes everything just that much worse.
Steels can work harden as well, 316L is somewhat infamous in that respect. Not as bad as Ti though.

Fyndium - 13-4-2021 at 11:46

Umm, yeah, about that hardness..

Titanium doesn't exactly cut it. Pun intended. It is PITA to work with, as it work hardens like nothing, and there are those who work with titanium, and then the rest of us who don't. Only inconels are comparable to the unmanageability of titanium.

But titanium isn't hard. It's very good structural material, as it's light and strong. But the HRC of it lacks, and even if it gets higher with some alloys, it's pretty much like using gold nuggets as shotgun pellets instead of lead or steel. Titanium isn't that expensive as material, as it's one of the most common elements on earth, but whatever's made of it, costs a lot because of it's difficulty in machining it, hence it's preserved for purposes it's most suitable, and that is aerospace and transplants due to biocompatibility.

If you need HARD mortar, get ceramic or hardened tool steel one. The ceramics do not have upper limit in hardness, but tool steels easily cross way over 60HRC and you will need some effort to put a dent in that. If what you are grinding is so hard that tungsten carbide, diamond and cubic boron nitride get scratched by it, then you will need to consider some other working methods, like laser cutting.

And, like I said, many times it's better to use expendable materials for some purposes. I've even discarded pots after boiling lead or some other nasty stuff because they were cheap and I didn't bother going through the trouble of cleaning them.

Fulmen - 13-4-2021 at 12:02

Titanium might be abundant, but the refining process (Kroll) is exceedingly inefficient and therefore costly.

RogueRose - 13-4-2021 at 14:30

I think you could make this pretty easily if you found a machine shop that will turn down a Titanium rod(s) for you.

https://www.ebay.com/itm/3-5-X-2-TI6-4-titanium-round-stock-...

This seller has tons of good Ti cheap. I think he even has up to 6" diameter round's and you can get it by the inch.
https://www.ebay.com/itm/Titanium-Round-Bar-6AL4V-1-375-x-12...

All you need for the pestel is various diameters turned down to a 1/2 sphere and tapered up maybe 1/2 inch. Then drill a hole, tap it, and make a steel handle with a screw coming out of it, so you could change the pestle head when you want or need to. You could make small ones to larger ones and vary the curve.

Fyndium - 13-4-2021 at 23:43

Quote: Originally posted by Fulmen

Titanium might be abundant, but the refining process (Kroll) is exceedingly inefficient and therefore costly.

Yes, compared to other metals, it's quite expensive. At cheapest, you can prepare to pay 10-50€/kg of the stuff, depending on form, alloy, quantity and other factors, like location. The mere materials cost for such mortar can be in order of 100-300€ depending on size, and as true socialists we do not count any added value for the work needed to turn that ingot into a mortar and a pestle.

pneumatician - 14-4-2021 at 04:53

well, thinking a bit about this subject after reading all this opinions... no matter if a mortar-pestle is mega hard, the problem arise when the material to crush is near or very near as hard like the combo mortar-pestle. So with a iron mortar can reduce to dust egg shell without any scrache or fear of losing shattered bits that contaminate the thing you want to crush, but with rocks... near hard as mortar the contamination by erosion and small chipped pieces is inevitable.

well to try this "theorie" I need to spend a lot of money buying a lot of mortars of every material on sale and inclusive making my own!!! :-(

redneck tech here do not work because too much contaminants and I want only the material crushed

https://www.youtube.com/watch?v=Rg6WrRzknWY

Morgan - 14-4-2021 at 07:16

I wonder if you could press/stamp form a bowl or mortar shape if you bought a round sheet or plate of titanium, maybe heating the metal to prevent cracking.
There're a lot of inexpensive camping titanium bowl shapes for sale if you could form a support mold or cladding underneath the titanium for strength.

Here's an expensive rice bowl however that has a somewhat appealing design.
https://www.eatingtools.com/home/80-ti-rice-bowl-titanium-by...

Speaking of insane pricing, it occurs to me my brother bought a pair of Van Staal titanium pliers/corrosion proof for fishing offshore in the gulf.

Fulmen - 14-4-2021 at 10:44

First off: Forget about titanium, it's not the solution even if the cost isn't an issue.

And it's not like you need something harder than the material you're grinding. I've crushed and milled a lot of quartz with steel jaw crushers and disk mills. Of course there is some wear, but it's not as bad as you might think. The reason is that steel is ductile while rock is brittle.

zed - 14-4-2021 at 21:11

Ummm. I'm thinking shock. Sledge hammer impact.

Thermal Shock, is a possibility too.

Or, lapidary equipment. Grind it up via Carbide (or Diamond) Grinding wheel.

You don't like tumbling/ball milling?

[Edited on 15-4-2021 by zed]

Praxichys - 15-4-2021 at 05:28

As Fyndium mentioned: titanium is falsely portrayed as some kind of miracle material; the truth is that steel beats the pants off it any day of the week in almost all applications.

Typical grades are on par with only mild steel (50-70ksi), and a well-selected grade of steel wins in all aspects - toughness, hardness, yield strength, and fatigue resistance. High strength titanium involves expensive alloys and typically requires forging; that is not what you'll get buying a bowl or a bar from eBay. You'll find that consumer products are made from the worst play-dough-grade Ti to keep manufacturing costs low and are more of a gimmick than anything.

Something as simple as off the shelf AISI 4140 steel bar stock with a little heat treatment is FAR tougher - the core somewhere around 130ksi and the surface HRC 63-65 - and everyone and their brother can machine it for you. (I'm a development engineer in the bearing industry, by the way - this is my wheelhouse)

Titanium shines in aerospace and defense because it is about 56% as dense as steel and stronger than most grades of aluminum (especially at higher temperatures), which makes it attractive for aircraft use. This unfortunately earns it the moniker of a "Military Grade" material, and salespeople will eagerly ram that down the throat of anyone who doesn't know much about why titanium is a terrible choice in any situation where weight is not of maximum importance.

To weigh in on the crushing issue, just wrap the rocks in a newspaper packet and go to town with a good hammer until you get the size you want. Otherwise, a ball mill is the obvious choice - very hard ceramic media is widely available should you need rock flour for some reason.

rockyit98 - 15-4-2021 at 09:24

if you can do this, epoxy bonded alumina or silicon carbide sand layer inside in a normal mortar (even wood) will give best of both world.as it's hard and not brittle, even when you hit it. just think of composite abrasive grinding wheels .I think the best way to do this is by applying medium viscosity take long time to harden epoxy and coating the inside of the mortar and out side of the pestle and filling and pressings the mortar with said sand and pushing the pestle in it. then let it cure and pure the excess sand and washing to clean it thoroughly. if you feeling adventures you can also now coat with low viscosity clear epoxy to make sand more secure.

unionised - 15-4-2021 at 10:05

Buy or make a percussion mortar.
https://www.ascscientific.com/geology-laboratory-equipment/j...

Steel is just fine.

[Edited on 15-4-21 by unionised]

Morgan - 15-4-2021 at 12:23

I remember telling a pulsejet enthusiast titanium wouldn't be a good choice for making a pulsejet. He went ahead and made one out of grade 2 titanium anyway but found it started flaking badly from reacting with the air.

"Testing out R/C control of a new 6" titanium valveless pulse jet. This Ti jet is about half the weight of an equivalent stainless jet at 2.4lbs. Too bad titanium can't take the heat. The combustion chamber began to ablate as soon as the jet got up to temp. Oh well. Back to stainless I guess

" https://www.youtube.com/watch?v=y8sxbw8u3e8

Grade 2 or chemically pure titanium forms cracks in automotive exhaust systems and the oxidation resistance is insufficient a Porsche article says at around 700 C or 1292 F.
Maybe because the SR-71 uses it people think it's good for "high" heat in air or that it excels in all areas or the best choice for strength or hardness.

Tidbit
https://www.amt-advanced-materials-technology.com/materials/...

[Edited on 15-4-2021 by Morgan]

pneumatician - 15-4-2021 at 14:08

Quote: Originally posted by Fulmen

First off: Forget about titanium, it's not the solution even if the cost isn't an issue.

And it's not like you need something harder than the material you're grinding. I've crushed and milled a lot of quartz with steel jaw crushers and disk mills. Of course there is some wear, but it's not as bad as you might think. The reason is that steel is ductile while rock is brittle.

Yuo are right but I search "pharma purity", ok I use steel, and with a magnet separate the pieces of mortar-pestle chipped... ha ha ha, the problem here?? ha ha ha, the rocks I want to reduce to dust are ferro-magnetic!!! :-)

pneumatician - 15-4-2021 at 15:03

Quote: Originally posted by zed

Ummm. I'm thinking shock. Sledge hammer impact.

Thermal Shock, is a possibility too.

Or, lapidary equipment. Grind it up via Carbide (or Diamond) Grinding wheel.

You don't like tumbling/ball milling?

[Edited on 15-4-2021 by zed]

thermal shock is the LAST option for me and maybe useless for the end result I are searching...

tumbling/ball milling I already say:

https://www.sciencemadness.org/whisper/viewthread.php?tid=15...

Morgan - 15-4-2021 at 15:08

I tried to find specific uses for a titanium mortar and pestles but couldn't locate any information. But I wonder what buyers are using them for as surely it's not just for the novelty?
However I did run across this unusually hard alloy of titanium and gold though and another ratio that's magnetic.
"When we tried to grind up titanium-gold, we couldn't," she recalled. "I even bought a diamond (coated) mortar and pestle, and we still couldn't grind it up."
https://phys.org/news/2016-07-lab-titanium-gold-alloy-harder...

Tidbit
https://www.sigmaaldrich.com/catalog/product/aldrich/z553328...

[Edited on 15-4-2021 by Morgan]

barbs09 - 16-4-2021 at 04:51

I assume the material you are crushing is quartz (Mohs =7), potentially for gold extraction?? Make a Dolly pot. Old timers (and not so old timers) use to use them to crush quartz vein material prior to panning for presence / absence of gold. These don't need to be a highly technical affair.

Cheers AB

unionised - 16-4-2021 at 05:18

Quote: Originally posted by pneumatician

I need a mortar for grind some rocks

Why?
If you tell us what rocks, and why you want them powdered it will help us to help you.

Fulmen - 16-4-2021 at 09:51

Quote: Originally posted by Morgan

https://phys.org/news/2016-07-lab-titanium-gold-alloy-harder...

I smell marketing BS.

- "It is about 3-4 times harder than most steels,"

Big deal, most steels aren't very hard. In fact this could be said of any tool steel and even plain carbon steel with the proper heat treatment.

- "It's four times harder than pure titanium"
Titanium Grade 1 (commercially pure, 99,5% Ti) has an ultimate strength of around 250MPa. So we're talking of 1500MPa or thereabouts. Now don't get me wrong, that's pretty impressive for a titanium alloy. But considering the price and density of gold I don't expect it to leave the lab anytime soon.

[Edited on 16-4-21 by Fulmen]

pneumatician - 16-4-2021 at 13:59

Quote: Originally posted by unionised

Why?
If you tell us what rocks, and why you want them powdered it will help us to help you.

why? why in the labs technicians want to reduce to dust rocks??

Gold and Silver ores, platinium sulfites, Gold sand... The Silver ore of the pic is fucking hard. The white dots are impacts with a heavy hammer and the tool bounce back! So I need to go outside or destroy the floor of the house :-)

RogueRose - 16-4-2021 at 15:28

Quote: Originally posted by pneumatician

Quote: Originally posted by unionised

Why?
If you tell us what rocks, and why you want them powdered it will help us to help you.

why? why in the labs technicians want to reduce to dust rocks??

Gold and Silver ores, platinium sulfites, Gold sand... The Silver ore of the pic is fucking hard. The white dots are impacts with a heavy hammer and the tool bounce back! So I need to go outside or destroy the floor of the house :-)

Are you being serious or are you trolling? You can't crush hard rock on a soft surface, even if you are using a hard hammer. Much of the energy is being absorbed by the softer material which is why the hammer bounced back.

Second, that rock looks like limestone.

So is your plan to extract PM's from ore? What quantites are you looking to process - couple lbs, hundreds or tons?

Anyway you look at it, the best option would be to find a piece of hard steel to place the rock on and then either hit it hard with something like a pic-axe or a sledge hammer. I'd suggest a hammer & hit it as hard as you can. If you need to contain it, get some plastic bags and put the rock inside that then smash it. I've done this before with rocks, boro glass & quartz glass and it works well. I used about 8-10 plastic bags from the grocery store. Nest the bags, put rock in, twist bag closed, turn bag inside out (while twisted closed) and repeat. You should be able to get 3-4 layers for each bag this way.

If you are going to be crushing lots of ore, look into some AR400 or AR500 steel.

[Edited on 4-16-2021 by RogueRose]

pneumatician - 17-4-2021 at 10:03

Quote: Originally posted by RogueRose

Are you being serious or are you trolling? You can't crush hard rock on a soft surface, even if you are using a hard hammer. Much of the energy is being absorbed by the softer material which is why the hammer bounced back.

Second, that rock looks like limestone.

So is your plan to extract PM's from ore? What quantites are you looking to process - couple lbs, hundreds or tons?

Anyway you look at it, the best option would be to find a piece of hard steel to place the rock on and then either hit it hard with something like a pic-axe or a sledge hammer. I'd suggest a hammer & hit it as hard as you can. If you need to contain it, get some plastic bags and put the rock inside that then smash it. I've done this before with rocks, boro glass & quartz glass and it works well.

If you are going to be crushing lots of ore, look into some AR400 or AR500 steel.

[Edited on 4-16-2021 by RogueRose]

Are you being serious or are you trolling?

"find a piece of hard steel to place the rock on and then either hit it hard" :-) this is what I make, with a piece of girder (steel).
Are you being serious or are you trolling?

the rock is a silver ore from a mine in open air.

not lb not tones, you not have idea of what I are doing or try to do?

conclusion until now, nobody here try to make a dust from a sample whitout any pollution fromm the mortar, etc used.

Color is important to detect what is in the sample, but a lot of "foreing" matter from the sample can inducce to error & and not being able to know that there is exactly, basically because i'm not testing with pounds or tons, and well, the quantity here is not important, more quantity more pollution from the method of reducing to dust, no?

pneumatician - 17-4-2021 at 14:33

Quote: Originally posted by Morgan

I tried to find specific uses for a titanium mortar and pestles but couldn't locate any information. But I wonder what buyers are using them for as surely it's not just for the novelty?
However I did run across this unusually hard alloy of titanium and gold though and another ratio that's magnetic.
"When we tried to grind up titanium-gold, we couldn't," she recalled. "I even bought a diamond (coated) mortar and pestle, and we still couldn't grind it up."
https://phys.org/news/2016-07-lab-titanium-gold-alloy-harder...

Tidbit
https://www.sigmaaldrich.com/catalog/product/aldrich/z553328...

[Edited on 15-4-2021 by Morgan]

so Ti + Pt = 16? times harder?

& Ti + Pt with a bit of Sb, 44? times more harder???

[Edited on 17-4-2021 by pneumatician]

Morgan - 17-4-2021 at 14:48

I really don't know how they are measuring hardness, just what I read.

"The team measured the hardness of the beta form of the crystal in conjunction with colleagues at Texas A&M University's Turbomachinery Laboratory and at the National High Magnetic Field Laboratory at Florida State University, Morosan and Svanidze also performed other comparisons with titanium."
https://phys.org/news/2016-07-lab-titanium-gold-alloy-harder...

Apparently there're some steels that are 4 times harder than others if you go by this Vickers hardness chart at the bottom.

"The fact that there are many ways to measure hardness, producing different numbers for the same specimen, graphically demonstrates that each method has it pros and cons. I won't go into that, however. As far as steel is concerned, numbers are usually given in either Vickers or Rockwell. With the figure from before you can easily convert from one scale to the other."

"Once more: No hardness test can compete with a tensile test; the latter gives far more information and numbers useful for calculations. But hardness tests are relatively cheap, easy to do, and in particular applicable to very small samples and samples with weird shapes."

"Just to put hardness in perspective, the following table gives the Vickers hardness of some common materials. Note that there are variations for one and the same material not only for steel but for almost everything. The number given thus must be seen as a typical harness."
https://www.tf.uni-kiel.de/matwis/amat/iss/kap_3/backbone/r3...

zed - 18-4-2021 at 05:32

Your response was in another string.

Ball Milling will reduce that stuff to dust. It might take a while.

Just turn it on, and let it tumble.

Don't even need ball bearings or carbide balls really.

Just the broken-up stones falling on each other, until they have ground each other into dust.

[Edited on 18-4-2021 by zed]

pneumatician - 18-4-2021 at 05:41

I send a email to Emilia Morosan here:

https://www.morosan.rice.edu/contact-me

maybe if not is an industrial secret come here to explain something about this alloy.

barbs09 - 19-4-2021 at 05:29

Its not clear to me whether you have pounds or tons of ore to crush: but prior to fire assay or digestion an analytical lab will likely use a jaw crusher to do an initial size reduction. Any tungsten or Fe contamination will be negligible and is likely not considered important for precious metal assays. Industrial scale gold processing plants will often also have a jaw crusher in its primary crush circuit prior to introducing the ore to a ball or SAG mill.

Just a quick google search found an inexpensive example of such a jaw crusher

https://www.911metallurgist.com/equipment/mini-rock-crusher/

Cheers, AB

OldNubbins - 19-4-2021 at 13:00

Contamination from processing equipment is magnitudes less than impurities already present in the ore.

Kind of like separating out the fly shit from the pepper.

Rock Tumbler

MadHatter - 19-4-2021 at 17:10

As stated, a rock tumbler, a.k.a. ball mill reduces to
dust if allowed to tumble for sufficient time. Even
at Moh's hardness 7 quartz will eventually reduce
to sand or something similar to diatomaceous earth.
It's a matter of patience.

As for mortar and pestles even the fused alumina
would take some time depending on how much
force is applied. Fused alumina can have a hardness
of 9 on the Moh's scale as this is basically corundum.
Comparable to ruby or sapphire.

Zed, you called it right.

[Edited on 2021/4/20 by MadHatter]