Sciencemadness Discussion Board - Identification of this metal

Identification of this metal

CHRIS25 - 24-4-2014 at 07:40

Had this for years, there is 3/4 kilogram here, when dropped on one another you get a firework display. But only now I thought to question whether it is ferro titanium or raw titanium. I read something by the by, quite by accident, and then thought Oh, I may not have pure titanium after all. Apart from some rainbow oxidation on some other piece it is relatively silver-grey all over except for the blue you see here on this piece. So I thought I would post the image to ask what others may think.

aga - 24-4-2014 at 07:55

Chuck it in a measuring jug of water and find it's volume (by displacement) then you can calculate the density, which should help identify it.

Depending on it's purity, it should be around 4.5 g/cc if it's titanium

[Edited on 24-4-2014 by aga]

CHRIS25 - 24-4-2014 at 09:03

Placed 664g in 400mLs water. 140mLs displaced density = 4.7

blogfast25 - 24-4-2014 at 09:59

Aha, I rather love these problems.

It rather looks like titanium. The blue thin layer diffraction you see can be seen on Ti too. And Ti sparks easily.

The density points strongly to a Period IV element or alloy thereof.

As luck would have it there's a simple and colourful test for Ti and you happen to have the reagents needed.

File (or break) off a bit of the chunk and drop it into conc. HCl. Heat gently if possible. Ti reacts with hot conc. HCl fairly vigorously. After 1/2 - 1 h your solution should be blue/purple, caused by Ti3+ ions.

Allow to cool and add a few drops of H2O2 (6 % is fine). This immediately oxidises the Ti (III) to Ti (IV) and forms a Ti(IV) peroxo complex that is vivid red in colour. The test is unmistakable.

This test will work also on ferrotitanium.

Where did you get this specimen? It's beautiful, congrats!

[Edited on 24-4-2014 by blogfast25]

Bert - 24-4-2014 at 10:09

What color are the sparks? Pure Ti sponge makes silver/white, Fe/Ti sparks are gold.

Pure Ti should be around 4.5g/cc density.

You can see the bubbles- I'd expect this sample to come in LESS dense than pure Ti due to the voids. How precise was your scale and volumetric flask?

CHRIS25 - 24-4-2014 at 10:54

Bert - How precise was your scale and volumetric flask? It was just a normal measuring jug. I will do the test again in a more gradated jug. The sparks are very difficult to say, I just dropped them a few times and multiple opinions go for more gold looking than pure white.

Blogfast - Where did you get this specimen? I used to be an international trucker, I got it in Germany when I was delivering 24 tons of it to a huge smelting works, when you tip 20 tons onto the floor in the factory - Wow, did I see some sparks. I will do the test tomorrow, but will the test indicate if it is alloyed

DraconicAcid - 24-4-2014 at 10:58

Quote: Originally posted by blogfast25

Aha, I rather love these problems.

It rather looks like titanium. The blue thin layer diffraction you see can be seen on Ti too. And Ti sparks easily.

As luck would have it there's a simple and colourful test for Ti and you happen to have the reagents needed.

File (or break) off a bit of the chunk and drop it into conc. HCl. Heat gently if possible. Ti reacts with hot conc. HCl fairly vigorously. After 1/2 - 1 h your solution should be blue/purple, caused by Ti3+ ions.

Allow to cool and add a few drops of H2O2 (6 % is fine). This immediately oxidises the Ti (III) to Ti (IV) and forms a Ti(IV) peroxo complex that is vivid red in colour. The test is unmistakable.

This test will work also on ferrotitanium.

Where did you get this specimen? It's beautiful, congrats!

[Edited on 24-4-2014 by blogfast25]

That will tell you if the piece contains titanium, but I get the impression that the OP is trying to decide if it's pure titanium or not. You could test for iron by adding thiocyanate to the solution (Vogel assures me that titanium doesn't interfere with this test).

CHRIS25 - 24-4-2014 at 11:06

Just placed 400mLs water in a fine gradated jug. Different Titanium piece weighed 405 grams. Water displaced = 86mLs, this was measured by extracting water from a jug with a syringe until level was down to 400mLs again. And guess what, Density is exactly 4.7 again.
Thanks Draconic, pity, I don't have any thiocyanate. and I am certainly not going make that one. (sulphur and cyanide)

DraconicAcid - 24-4-2014 at 11:36

I checked Vogel's Quantitative analysis to see if there was a way to figure out what % of your metal is titanium, but none of the procedures there lend themselves to home chemistry.

blogfast25 - 24-4-2014 at 11:39

You could test for iron by allowing the solution of Ti/FeTi (?) to sit in a shallow dish for a couple of days. Air oxygen will oxidise both Fe (II) and Ti (III) to Fe (III) and Ti (IV). Chances are that by then Fe(OH)3 will start precipitating.as a reddish brown precipitate.

[Edited on 24-4-2014 by blogfast25]

CHRIS25 - 24-4-2014 at 11:59

Thanks Draconic. Blogfast just did this, we'll see.

blogfast25 - 24-4-2014 at 12:13

Quote: Originally posted by CHRIS25

Just placed 400mLs water in a fine gradated jug. Different Titanium piece weighed 405 grams. Water displaced = 86mLs, this was measured by extracting water from a jug with a syringe until level was down to 400mLs again. And guess what, Density is exactly 4.7 again.

Are you aware of this neat little trick to determine displaced volume:

http://oxfordchemserve.com/density-of-solid-objects-archimed...

Magic: no syringe!

CHRIS25 - 24-4-2014 at 13:25

I weighed the titanium = 405grams. I zeroed the scales with water and dipped the piece into the water attached to thin copper wire. The scales measured 76 grams. 405/76 = 5.3. that is one huge difference.

Bert - 24-4-2014 at 13:31

If you were delivering by the multi ton to a steel works, this is almost certainly ferro Titanium. They use it to remove certain impurities out of molten Iron- Sulfur, Nitrogen, Oxygen and Carbon react with the Ti and end up as slag floating on the melt.

"Titanium, the nymphomaniac of metals- Get it hot enough and it'll combine with ANYTHING!"

CHRIS25 - 24-4-2014 at 13:40

Oh, that makes sense then.

blogfast25 - 25-4-2014 at 04:05

With Fe at 7.87 and Ti at 4.5, 5.3 would make sense for a FeTi.

The vacuoles in the metal would be consistent with aluminothermic preparation (thermite), as is used for ferrotitanium.

I'm reasonably sure that ferrotitanium is also used as 'master batches', to spike certain alloys with small amounts of Ti (property enhancement of alloys).

[Edited on 25-4-2014 by blogfast25]

CHRIS25 - 25-4-2014 at 04:45

Absolutely. And this method you pointed out is a more accurate measurement for density. Thankyou.

blogfast25 - 25-4-2014 at 07:31

The error with the first method arises when you use a fairly large cylindrical vessel. A small uncertainty in the exact level is magnified by multiplying it with π R2, the surface area of the water. Since as reading the exact level is difficult, measuring error tends to be quite large. But I'm sure you figured that out by now.

[Edited on 25-4-2014 by blogfast25]