Sciencemadness Discussion Board - Mortar And Pestle Composition

Mortar And Pestle Composition

MadHatter - 17-10-2007 at 15:26

I'm curious as to what your favorite mortar and pestle compositions are ?
I have 5 of them: porcelain, stainless steel, onyx, glass, cast iron. The cast iron
model is the most recent. With its very heavy pestle, grinding down materials
is almost effortless. Of course, my ballmill is preferred for any large amounts.
When it comes to very fine powdering, my glass model is probably the best.
I keep the onyx(Smithsonian Institute - Museum Of Natural History gift shop) for
display purposes only.

Any thoughts or flames ?

Magpie - 17-10-2007 at 16:33

I use my big Coors (4-5") porcelain mortar & pestle quite often. I would use a small onyx or agate set (if I had one) for preparing samples for melting points. I also have an iron set that I bought for pulverizing gold bearing quartz. But I still had to ball mill the powder before doing the fire assay.

I just like the looks of them also. I suspect you do too.

Ozone - 17-10-2007 at 17:06

Ditto with the Coors. I use a small, highly polished agate model for mixing KBr and sample prior to pellet pressing for IR. The smooth surface does not take up particles like the rougher porcelain.

I must agree and add that nothing (except maybe a Jacob's Ladder) evokes "science" more strongly than a retort sitting next to a mortar and pestle

.

Cheers,

O3

chemrox - 17-10-2007 at 21:38

Ditto ditto a big Coors pestle and bigger mortar (to fit my hand) for grinding reagents and a small agate one for KBr mixing. No glass ... no metals ... I wish I had a retort ..Just for looks .. I do have a sidearm flask ...

Sauron - 18-10-2007 at 04:19

Apart from the typical lab types as listed above, I have made use of large (like 8-10" stone mortars and pesters and wooden ones for pulverizing herbs. These are common kitchen implements in Thailand. In fact the kitchen pestle is the Thai housewife's domestic weapon, equivalent to an American wife's rolling pin. For braining the errant husband as an object lesson.

not_important - 18-10-2007 at 04:55

I echo much of what has already been described. I have a copy of stainless steel M&P made in India, one reserved for spices, and a stone M&P like Sauron's that is great for grinding chilies as well as preliminary crushing of cassia bark and turmeric root. I've also a small set made from synthetic sapphire that is intended for sample prep, it resembles the agate morters favored for IR sample prep.

Phosphor-ing - 18-10-2007 at 05:41

Quote:

Originally posted by Sauron
In fact the kitchen pestle is the Thai housewife's domestic weapon, equivalent to an American wife's rolling pin. For braining the errant husband as an object lesson.

LOL *ducks, as flying plates crash against the wall and shatter, just in time to catch the flying pestle on the back of the head! Pop knots ensue.*

I have 2 small porcelain M&P, about 2" & 3", and a large porcelain one, 6"+ with the wooden pestle Sauron mentions above. Pop knots included!

Sauron - 18-10-2007 at 06:10

Indeed it is mainly for chilis that Thai cooks use the M&P and when they do the Thai kitchen assumes a most interesting atmosphere indeed.

The familiar pok pok pok of a Thai girl sitting on the floor with M&P between her thighs...

Phosphor-ing - 18-10-2007 at 06:38

I use the large mortar w/ wooden pestle to grind up Glucosamine and Chondroitin tables to be spread over the dogs food in the evening. She wont take the pills whole, but ground up and mixed in a can of dog food and she devours it.

Mr. Wizard - 18-10-2007 at 07:42

I have a large and small cast iron mortar and pestle; lucky acquisitions from a second hand store. They are more suitable for grinding mining samples than chemistry, as any product will have a healthy dose of iron added. I also have a small Coors porcelain one for when purity is an issue. It can also be cleaned more thoroughly.

The mortar and pestle is also the recognized sign for pharmacies here in the US. The Alembic, even though most don't know what it's called, is a more recognized chemistry symbol. The test tube and Erlenmeyer flask are also very recognized.

Fleaker - 18-10-2007 at 10:24

I have a 320mm diameter Coors one, and then a small 85mm one from agate.

Anyone ever got to use one of those tiny little alumina mortar and pestles? They're pinkish in colour and fairly expensive, but they grind very well!

Panache - 26-2-2008 at 21:41

i have one made out of dry ice glass but i find it really impractical to use. Firstly it burns the crap out of your hands then it sublimes to nothing after first condensing water all over your sample, so annoying.

MagicJigPipe - 26-2-2008 at 21:51

What? You can't be serious. I have never heard of that. I mean, I suppose I can see what it would be useful for but... like you said, the sublimation, condensation and subsequent freezing of water vapor, the extreme cold. Not to mention you would have to replace it every time it was used.

Am I missing something? Is the joke on me or does that actually exist?

chemrox - 26-2-2008 at 22:58

I have a large Coors for the lab .. mortar is over sized relative to the pestle for grinding ease. I have a 55 mm agate set for melting pint mixes, KBr pellets and making mulls. In my kitchen I have a medium size porcellain one since the Coors went to the lab and I have an extremely hard bamboo one as well. Came from Thailand.

Panache - 27-2-2008 at 15:43

Quote:

Originally posted by MagicJigPipe
Am I missing something? Is the joke on me or does that actually exist?

It was a very dry joke.

HA!! A PUN!!!!

However i think this thread should now include ridiculous suggestions for inconvenient materials to construct mortar and pestles out of. Points if you actually construct it and post a photograph.

PHILOU Zrealone - 28-2-2008 at 03:26

Quote:

Originally posted by Panache

Quote:

Originally posted by MagicJigPipe
Am I missing something? Is the joke on me or does that actually exist?

KClO3/P2S5 mortar

bfesser - 28-2-2008 at 05:53

Quote:

Originally posted by Fleaker
Anyone ever got to use one of those tiny little alumina mortar and pestles? They're pinkish in colour and fairly expensive, but they grind very well!

I've got a very tiny very hard and smooth mortar and pestle that might be made out of alumina. It seems too smooth to be made out of porcelain. It's not pinkish though, just sorta off-white. It's probably only an inch or so wide. I can post a picture if you like.

I also have a large marble, a medium sized brass, and a standard Coors ceramic. Used to have two others for cooking, but I gave them away. Mortars and pestles are as indispensable in the kitchen as in the lab.

garage chemist - 28-2-2008 at 08:08

I have one porcelain mortar, and I don't really understand why one would need more than one mortar in the home lab.
I have never needed a different one, ever.
Iron is attacked by some substances, agate is not good for tough materials like chlorine tablets. Porcelain seems universally useable for everything.

bfesser - 28-2-2008 at 08:17

Porcelain cross contaminates samples because of it's porosity, which is why agate mortars come in handy--especially for IR prep. Having more than one mortar and pestle is like having more than one flask. You need to have the right size, shape, and material for the job. You wouldn't want to use an iron mortar and pestle to prepare an IR sample, just as you wouldn't want to use a plastic flask to boil a high-boiling organic.

That being said, porcelain is probably the best for all around grinding work--if you only have a choice of one material. It's got the porosity problem, but it's hard enough to grind hard materials without issue (also has a slightly rough surface, which makes fine grinding easier), it's cheap enough to be expendable under certain conditions (not like agate), it's not as fragile as glass, and not prone to attack from acids like metal mortars.

Personally, I'd really like to get my hands on an agate mortar and pestle, but they're out of my price range for now.

[edit]
I forgot to mention that you will have issues with loss of product when grinding very small quantities (perhaps a few mg) in a medium or large-sized porcelain mortar. And, porcelain makes working with sticky compounds more difficult.

[Edited on 2/28/08 by bfesser]

Phosphor-ing - 28-2-2008 at 08:26

I also only have a porcelain mortar and pestle. I do have 2 sizes medium and small. I agree with garage chemist there really is no reason, I can think of, to have anything but porcelain in a home lab setting. Maybe for aesthetics but that's it.
@bfesser not to many amateur chemist have IR available to them.

bfesser - 28-2-2008 at 08:32

Quote:

Originally posted by Phosphor-ing
@bfesser not to many amateur chemist have IR available to them.

We can dream, can't we?

[Edited on 2/28/08 by bfesser]

Magpie - 28-2-2008 at 19:24

I needed to grind up a gold bearing quartz ore. For that I bought an iron mortar & pestle. I would have been afraid to attempt this grinding with my Coors porcelain set.

[Edited on 28-2-2008 by Magpie]

domaani - 15-3-2008 at 17:33

Quote:

Alkuperäinen lähettäjä bfesser

Quote:

Originally posted by Phosphor-ing
@bfesser not to many amateur chemist have IR available to them.

We can dream, can't we?

Oh yes we can.

I got a Perkin Elmer 1600 FTIR unit for a Christmas present last year. I just had to get one after finding out the value of the similar unit I demolished for parts many years ago (found it from a local junkyard). What a tragedy, although I'm now almost getting over it.

I asked a friend to manufacture an agate M&P for IR sample preparation, he's a member of a local Stone Club. It'll cost me a bottle of liquor. Shopping for a new one was never an alternative, the prices seem to be quite awkward.

microcosmicus - 15-3-2008 at 18:51

For most purposes, I do just fine with a small porcelain mortar and pestle which I
picked up at the dollar store around the corner.

As for why anyone might legitimately want something other than
porcelain in a home laboratory, one answer is if they happen
to do chemistry at high temperatures and want to grind up things like
calcium aluminate or make glass frit form pieces of broken glass. Hard
materials like that (basically the same stuff the geologists encounter
in their mineral samples) can chew its way right through porcelain, so I
instead powder it using a hammer on a steel plate. One of these years,
I plan to make a mortar and pestle of tool steel or cast iron for tasks like this.

As for fantasies, mine would be a mortar and pestle made of diamond.

Another thought, not so fantastic, is to tie this discussion in with the
thermite thread --- make molten titanium using blogfast's reaction
and cast a mortar and pestle. Both the physical toughness and the
chemical resistance of titanium sound like they would suit
it to this task.

12AX7 - 15-3-2008 at 19:04

Eh, titanium's strong, but steel has the edge (-holding capability).

What you want is manganese steel (about 5-15% alloy, IIRC), for abrasion resistance. They use that shit for *backhoe* buckets and teeth. Actually I'm not sure what the teeth are, I imagine they are something directly from the gates of hell! That's what you really want.

A similar proposition (i.e., a case of favorite alcoholic beverage) might get a tool and die maker to carve you one from a block around the shop.

Tim

bfesser - 15-3-2008 at 19:05

Tungsten, anyone?

12AX7 - 15-3-2008 at 19:07

OOH! Let's get together and carve one for Theodore Gray and/or Oliver Sachs!

Tim

Zinc - 26-3-2008 at 17:43

I have two M&P made from porcelain (one smaller and one larger). They have a rough interior. I also had one with a smooth interior but it fell

TDCFMOG - 5-4-2008 at 23:39

Quote:

Originally posted by FleakerAnyone ever got to use one of those tiny little alumina mortar and pestles? They're pinkish in colour and fairly expensive, but they grind very well!

I was looking at mortar and pestles online and the alumina ones I've found don't seem to be pinkish but are expensive.

However the Diamonite mortar and pestle listed on Fisher's website is pink and painfully expensive.

Edit: On Fisher's website they claim the Diamonite mortar and pestle is good for "grinding materials not easily reduced in porcelain or metal mortars".

https://www1.fishersci.com/wps/portal/PRODUCTDETAIL?productI...

[Edited on 6-4-2008 by TDCFMOG]

Neil - 9-4-2008 at 17:23

Quote:

Originally posted by 12AX7
Eh, titanium's strong, but steel has the edge (-holding capability).

What you want is manganese steel (about 5-15% alloy, IIRC), for abrasion resistance. They use that shit for *backhoe* buckets and teeth. Actually I'm not sure what the teeth are, I imagine they are something directly from the gates of hell! That's what you really want.

A similar proposition (i.e., a case of favorite alcoholic beverage) might get a tool and die maker to carve you one from a block around the shop.

Tim

AR400 IIRC

I use a cast iron M&P great wear considering it's felt nothing but Mn/Ti, Al2O3 and raw Si...

cbfull - 16-6-2008 at 18:29

Hah! I was waiting for someone to mention the "Diamonite" or sintered sapphire mortar and pestle. I was lucky enough to find one of the BIG ones at work literally a couple months before they threw everything away! This fool who was working in our glassware washroom thought it would be a good idea to take all the boxes and shelves of old condensers and such (this M&P was with this stuff) and put it in the garbage crusher.

He didn't get fired but they did move him back to maintenance.

I imagine that diamonite thing would've destroyed the crusher anyway.