Thread: Chromium Oxide 1.0?

Originally Posted by hi_bud_gl

chro2 will be only 1 size.

I've done a fair amount of research on chromium oxide. The kind we use is Chromium (III) Oxide CR2O3. It's a non-toxic version of chromium oxide.

I recall receiving a spec sheet after much back and forth from a Chromium Oxide manufacturing rep which listed an average particle range of different grades of chromium oxide. The largest average particle range in one of the available grades in descending order was 1.7 micron, .8 micron, .7 micron and .6 micron with different purity levels even within those four categories.

I guess that means that chrome ox is available in different particle ranges other than ".5 micron". I put the quotes around the .5 micron for a reason since it would be inaccurate for any supplier or manufacturer of any abrasive to state that ALL particles in an abrasive media would be guaranteed to be the exact same particle size. In our beloved ".5 micron" chrome ox, we've come to believe, we'd like to believe or we think we're certain that we're using a powder that contains only .5 micron particle chrome ox. That's only an average no matter where it comes from.

Chris L

I will try to make this simple.
Water is H20
doesn't matter where or how you get water -it will be H20.
Now you could join salt etc and by doing so you can change weight, consistency etc but water will be same H20 .Will never ever change.
hope this helps.

CR2O3 doesn't matter where or how and when you get CR2O3 you should end up CR203. You can add different ingredients and change weight etc.

I'm confused, Sham. The manufacturer I received information from back then made reference in their materials to milling, separating and sifting CR203 to different particle sizes. My point was that it's apparently possible to purchase chromium oxide in different average particle size other than .5 micron.

Chris L

ChrisL of course you can buy in different sizes but that differences made not by chro2. it has been made what other ingredient has been added to it.
Lets say chr02 is 0.5 size you can add a larger ingredient and make size 1.0 etc.etc.
Actual chro2 will never change.
hope this is clear.

I'm embarrassingly ignorant in this area, Sham. I'm afraid I still don't understand. A CR203 molecule would be smaller than .5 micron, wouldn't it?

This is where my ignorance is limiting: I think of chromium oxide as a substance. I think of "diamond" as a substance. Diamond particles can be different sizes and it doesn't take other ingredients added to the "diamond" to change the particle size.

Any additional help would be appreciated.

Thanks.

Chris L

ok lets try a little different way.
example .
CO2. HAS weight 1 kg.
now we can get CO2 IN many different ways right? burning,chemical reactions etc etc.
and we get get in in different countries example
usa gets it by chemical way
Russia by burning woods etc etc.
end result is CO2

right. CO2 never changes still same CO2.

Now you can mix is with different helium etc gases and get a little lighter or heavier gas but clean CO2 WILL be always CO2.

Originally Posted by hi_bud_gl

I will try to make this simple.
Water is H20
doesn't matter where or how you get water -it will be H20.
Now you could join salt etc and by doing so you can change weight, consistency etc but water will be same H20 .Will never ever change.
hope this helps.

CR2O3 doesn't matter where or how and when you get CR2O3 you should end up CR203. You can add different ingredients and change weight etc.

Hmm, Oxygen is O2 but there's O3 and O5 too. And what about heavy water?

The ore for chrome is Chromite which is Cr2O4 with added iron and magnesium depending on purity.

Most chrome oxide is made for lapidary work so it can be ground to different grits according to need no different than alumina is.

I don't see any reason why the formula can't be artificially adjusted no different than iron oxide has several variants as long as the compound is stable and will bond together.

I would assume that .5 microns refers to the size of a single molecule of CR2O3 (two chromium atoms and three oxygen atoms).. which I intuitively agree with hi_bud_gl that it would always remain constant.

I guess this would leave the rest up to level of purity?

I've come across some chromium oxide on the internet, being sold for cosmetic value - as a green pigment. Though I have already arranged with Chris for him to send me some of his, I'm curious how pure this cosmetic chromium oxide would be, just as a general rule. I mean, it does say "chromium oxide"... I wonder if it would be 0.5 microns as well.

lets try this

Originally Posted by thebigspendur

Hmm, Oxygen is O2 but there's O3 and O5 too. And what about heavy water?

Code:

O2 =oxygen,when you O3= NAME CALLED ozone

The ore for chrome is Chromite which is Cr2O4 with added iron and magnesium depending on purity.
YES you are saying added this is a key key

I will jump in here, being a chemist I am sorry I have to disagree with you Hi-bud-gl,
I hope yo don´t take offense.

Chromium Oxide (ie Cr2O3) is the name of a pigment that is green in color.
Like ANY other pigment or cristalline structure there are many, literally infinately many variations
depending on how much time the crystalls had to bind each other
and some other variables like temperature and pressure I guess.
That´s why one could think of a single chromium oxide piece as big as the hope diamond.
Cr2O3 is a bad example for this, but how about Alumoxyde.
Al2O3 is available in any grit size, even as big as a palm
in the form of jade!
Believe me the molecular size of Cr2O3 is WAAAAAAAAAY smaller than 0.5 micron.

Cr2O3 has been commonly used as polishing compounds before,
that´s why 0.3 to 0.5 micron particles were mainly produced.
But if you buy some chromium oxide you don´t have a clue what grain size it actually has!
That´s why we in germany use Lukas Acrylic Color with the Pigment PG17 (wich is Cr2o3),
it definitly has a grain size of 0.3 to 0.5 micron.
There are however many other grain sizes like 12 micron.

btw: this can not be solved by adding or taking some elements out of the compund.
Cr2O3 is Cr2O3 or its not our chromium oxide.
Being crystalline however we "could" say (Cr2O3)n
n being the number of molecules in one cluster.
But still this would not lead anywhere.

but to answer the original question: I don´t know of any source for chromium oxide
in 1 micron.
You should go for Al2O3 or Diamond