Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: 1952 soviet dentist amalgam composition
DrScrabs
Hazard to Others
***




Posts: 123
Registered: 13-3-2018
Location: Laputa
Member Is Offline

Mood: Still evaporating..

[*] posted on 12-8-2019 at 01:44
1952 soviet dentist amalgam composition


So I went to a flea market and got some amalgam, I think it is yet to be mixed with Hg, and was wondering about the composition.
Wiki says that in the first half of the 20th century they used mostly premixed copper amalgam, wich had to be heated to use it. Nowdays it has a composition of about 40% Silver, max 32% Tin, max 30% Copper, max 5% Indium, maxi 3% Mercury and max 2% Zinc.
I hope it to be Silver amalgam of course :)
Sadly I dont speak or read russian and nobody was able to help me yet with the instructions that were included. Maybe here is somebody who is able to help. But the photos of the instruction are horrible so I will post scans when I am home on thursday.

Thank you!
DrScrabs

DSC08051.JPG - 1.6MB
View user's profile View All Posts By User
DrScrabs
Hazard to Others
***




Posts: 123
Registered: 13-3-2018
Location: Laputa
Member Is Offline

Mood: Still evaporating..

[*] posted on 12-8-2019 at 01:55


Managed to get the photos right :)

DSC08052.JPG - 2.7MB

DSC08053.JPG - 2.3MB

DSC08054.JPG - 2.3MB

DSC08055.JPG - 2.4MB
View user's profile View All Posts By User
Ubya
International Hazard
*****




Posts: 770
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline

Mood: I'm a maddo scientisto!!!

[*] posted on 12-8-2019 at 04:11


you could try the app version of google translate, it has a camera function that can translate live writings on things (thats how i found out in the Netherlands that the milk carton i bought was porridge, ans not chunky expired milk)




---------------------------------------------------------------------
feel free to correct my grammar, or any mistakes i make
---------------------------------------------------------------------
View user's profile View All Posts By User
TheMrbunGee
National Hazard
****




Posts: 260
Registered: 13-7-2016
Location: EU
Member Is Offline

Mood: Phosphorising

[*] posted on 12-8-2019 at 06:59


the text is all instructions on use for filling cavities, but it is called "copper amalgam" ,so I suspect there is copper.

My rusty russian would use more time than I got right now, but running trough it I did not see any indigents listed. But I am sure that it is premixed copper amalgam you mentioned.

edit:

Silver ones comes in 2 parts, silver + other metals powder and Hg. You mix them right before filling cavity.

[Edited on 12-8-2019 by TheMrbunGee]




View user's profile Visit user's homepage View All Posts By User
teodor
Hazard to Others
***




Posts: 164
Registered: 28-6-2019
Location: Heerenveen
Member Is Offline


[*] posted on 13-8-2019 at 05:52


This instruction clearly says that this is a"copper precipitated from a solution by chemical or electrical way already mixed with mercury. The first part describes the preparation of a dental filling with removing excess of mercury which should appear on the surface of bricks after heating as drops.

Well, you can U2U me if need some translation from Russian :)


[Edited on 13-8-2019 by teodor]

[Edited on 13-8-2019 by teodor]
View user's profile View All Posts By User
DrScrabs
Hazard to Others
***




Posts: 123
Registered: 13-3-2018
Location: Laputa
Member Is Offline

Mood: Still evaporating..

[*] posted on 14-8-2019 at 11:43


Thanks teodor.
Good to know its the copper amalgam, now I just have to find a way to get the mercury :D
I think I will dissolve all in nitric acid and displace the Hg(II) with some copper.
Or does somebody have a better idea?
View user's profile View All Posts By User
egret
Harmless
*




Posts: 9
Registered: 22-2-2018
Member Is Offline

Mood: No Mood

[*] posted on 14-8-2019 at 18:29


I am afraid you get the copper amalgam back. Or the mercury will be contaminated by copper. The comosition of this amalgam is 32—37% Cu, 59—66% Hg, 2—4% Zn

View user's profile View All Posts By User
DrScrabs
Hazard to Others
***




Posts: 123
Registered: 13-3-2018
Location: Laputa
Member Is Offline

Mood: Still evaporating..

[*] posted on 15-8-2019 at 00:50


I don´t think I will get the amalgam again. I will use 1-2mm copper wire and immerse it into the liquid without going to the bottom of the beaker.
That way the mercury wick forms on the surface will drip off. It will be contaminated wirth copper of course but the contamination is much less Cu than the starting amalgam, so to clean the mercury, I will have to stir it in KMnO4 soln to oxidise the Cu, then wash with dilute acid to get rid of the oxides.
But hey, i payed like 15 Eur for it, if I get 60g of Hg, that was worth it for me.


[Edited on 15-8-2019 by DrScrabs]
View user's profile View All Posts By User
DrScrabs
Hazard to Others
***




Posts: 123
Registered: 13-3-2018
Location: Laputa
Member Is Offline

Mood: Still evaporating..

[*] posted on 17-8-2019 at 02:06


I got an good idea how to seperate the copper and mercury without distillation. As I need the Hg as Hg(II) this may be the best way for me.
First dissolve the amalgam in excess azeotropic HNO3.Then dilute with some water and boil the soln for a few minutes to get rid of dissolved NOx. There will be a soln of Cu(NO3)2 and Hg(NO3)2. Then the minimum amount of aq ammonia is added to precipitate Cu(OH)2. Hg(NO3)2 is not affected by aq ammonia if I remember right. The presence of Cu(II) can be easily determined by the colour of the solution.
Filter and then boil dry and decompose the Hg(NO3)2 to HgO. Then proceed with the acid of your choice to get Hg(II).

What do you think about?
View user's profile View All Posts By User
teodor
Hazard to Others
***




Posts: 164
Registered: 28-6-2019
Location: Heerenveen
Member Is Offline


[*] posted on 19-8-2019 at 05:59


Well, I think that upon addition HNO3 will react with Cu first and then with Hg (based on reactions between Cu metal and Hg salts - it always deposits Hg).

The main problem with any method of separation I think is volatility of Hg salts. I have no experience with that so probably would do heating/boiling of Hg salt solution with the same precautions as actual distillation of Hg.

Also, there is reaction between mercuric salt and formic acid, if I remember it correctly, that reduces Hg2+ to Hg metal, which probably could be separated by gravity after boiling the water suspension. But I didn't try that.


[Edited on 19-8-2019 by teodor]

[Edited on 19-8-2019 by teodor]

[Edited on 19-8-2019 by teodor]
View user's profile View All Posts By User
icelake
Harmless
*




Posts: 48
Registered: 9-10-2017
Member Is Offline

Mood: No Mood

[*] posted on 19-8-2019 at 06:45


Quote: Originally posted by DrScrabs  
Hg(NO3)2 is not affected by aq ammonia if I remember right.


Apparently aqueous ammonia produces insoluble amido salts (mercury amidonitrate in this case).

https://chem.libretexts.org/Bookshelves/Analytical_Chemistry...

Aqueous ammonia produces white amido salts whose composition depends on the mercury(II) salt present in the solution:

HgCl2(aq)+2NH3(aq)↽−−⇀HgNH2Cl(s)+2NH+4(aq)+Cl−(aq)

These salts are not soluble in excess aqueous ammonia, but do dissolve in acids.
View user's profile View All Posts By User

  Go To Top