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fluorite3377
Joined: 11 Feb 2015
Posts: 1
Location: ILLINOIS
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Posted: Feb 18, 2015 16:47 Post subject: Removing hematite from calcite |
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Could anyone help on how to remove hematite from calcite without damaging the calcite>
Thanks |
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GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
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Posted: Feb 18, 2015 17:08 Post subject: Re: Removing hematite from calcite |
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Super Iron Out. Try on a piece you don't mind destroying. |
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kushmeja
Joined: 28 Jul 2014
Posts: 244
Location: New Jersey
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Posted: Feb 18, 2015 17:10 Post subject: Re: Removing hematite from calcite |
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If you're referring to the actual mineral hematite, you're probably not going to be able to remove it.
If you're simply referring to a rusty coating of iron oxide, then you can use Super Iron Out or something similar that will break down and dissolve the iron into solution, thus allowing it to be more easily scrubbed off. Even then, if it's really bad iron staining, you're going to have issues getting it all off no matter what you use most likely. You can also use an ultrasonic cleaner or a spray cleaning gun if you have one. |
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GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
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Posted: Feb 18, 2015 17:23 Post subject: Re: Removing hematite from calcite |
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kushmeja wrote: | If you're referring to the actual mineral hematite, you're probably not going to be able to remove it.
If you're simply referring to a rusty coating of iron oxide, then you can use Super Iron Out or something similar that will break down and dissolve the iron into solution, thus allowing it to be more easily scrubbed off. Even then, if it's really bad iron staining, you're going to have issues getting it all off no matter what you use most likely. You can also use an ultrasonic cleaner or a spray cleaning gun if you have one. |
Agreed. A photo is always useful. And a locality, as folks may have some experience with the particular material to be cleaned. |
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lluis
Joined: 17 Nov 2006
Posts: 711
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Posted: Feb 19, 2015 01:33 Post subject: Re: Removing hematite from calcite |
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Good morning to all
If I am not wrong, IronOut is something acidic (Oxalic acid inside?). If so, not a good idea on calcite.
May you try the mixture of sodium citrate, bicarbonate and hydrosulphite?
A reductor to change hematite to a ferrous oxide/hydroxide, citrate to complex it, and bicarbonate to maintain solution slightly basic...
Takes time, but it does not damage calcite....
Maybe with sodiumborhydride, sodium citrate and bicarbonate would go quicker.... And I doubt it touches calcite.
First solution has a name. which I use do not remember... In an article of John Betts (hi, John!), it is explained.
Maybe John could help....
With best wishes
Lluís |
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Dehne
Joined: 27 Mar 2013
Posts: 11
Location: Hobart, Tasmania
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Posted: Feb 19, 2015 03:28 Post subject: Re: Removing hematite from calcite |
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lluis wrote: | Good morning to all
If I am not wrong, IronOut is something acidic (Oxalic acid inside?). If so, not a good idea on calcite.
May you try the mixture of sodium citrate, bicarbonate and hydrosulphite?
A reductor to change hematite to a ferrous oxide/hydroxide, citrate to complex it, and bicarbonate to maintain solution slightly basic...
Takes time, but it does not damage calcite....
Maybe with sodiumborhydride, sodium citrate and bicarbonate would go quicker.... And I doubt it touches calcite.
First solution has a name. which I use do not remember... In an article of John Betts (hi, John!), it is explained.
Maybe John could help....
With best wishes
Lluís |
Its called Wallers Method. The formula can be found searching on these words.
Cheers
dehne _________________ Dehne McLaughlin
Hobart
Tasmania
Australia |
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lluis
Joined: 17 Nov 2006
Posts: 711
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Posted: Feb 19, 2015 06:09 Post subject: Re: Removing hematite from calcite |
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Thanks a lot, Dehne!
With best wishes
Lluís |
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kushmeja
Joined: 28 Jul 2014
Posts: 244
Location: New Jersey
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Posted: Feb 19, 2015 07:34 Post subject: Re: Removing hematite from calcite |
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lluis wrote: | Good morning to all
If I am not wrong, IronOut is something acidic (Oxalic acid inside?). If so, not a good idea on calcite.
May you try the mixture of sodium citrate, bicarbonate and hydrosulphite?
A reductor to change hematite to a ferrous oxide/hydroxide, citrate to complex it, and bicarbonate to maintain solution slightly basic...
Takes time, but it does not damage calcite....
Maybe with sodiumborhydride, sodium citrate and bicarbonate would go quicker.... And I doubt it touches calcite.
First solution has a name. which I use do not remember... In an article of John Betts (hi, John!), it is explained.
Maybe John could help....
With best wishes
Lluís |
Super Iron Out isn't an acid, and it shouldn't damage the calcite. It's a white powder that you mix with water, and it's active ingredients are sodium metabisulfite and sodium hydrosulfite. I've personally used it on a wide variety of minerals and have no issues with it. That being said, you should always test out a small or poor quality piece first just to be sure. |
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lluis
Joined: 17 Nov 2006
Posts: 711
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Posted: Feb 19, 2015 10:36 Post subject: Re: Removing hematite from calcite |
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Hi, Kushmeja
I suppose that that is chemist things, but sodium metabisulphite *is* acidic, and can corrode calcite. So IronOut *is* acidic, unless carbonate or bicarbonate is added in recipee.
And, sodium hydrosulphite when oxidizes, produce sulphuric acid, that by sure attacks calcite. unless carbonate or bicarbonate is in the recipee.
But if basic pH is in the product, then, it would not remove iron unless a complexant is there..
So, if it is not a version of Wallers recipee, well, it would corrode calcite and any carbonate, if long time let, and big amount used (that, for the less reactive carbonates....)
With best wishes
Lluís |
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GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
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Posted: Feb 19, 2015 10:59 Post subject: Re: Removing hematite from calcite |
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SIO is slightly acidic, pH 5.5 to 6.0. It have been used effectively to clean carbonates, like Azurite and Calcite, but it depends on the particular locality. That is why you always test on a piece of rubble.
This whole issue was described in detail earlier -- https://www.mineral-forum.com/message-board/viewtopic.php?p=33250 |
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lluis
Joined: 17 Nov 2006
Posts: 711
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Posted: Feb 19, 2015 11:22 Post subject: Re: Removing hematite from calcite |
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Hi, GneissWare
Thanks a lot!
If pH is 5,5-6, it would turn far more acidic when working....and calcite would suffer.
To buffer it, bicarbonate powder would be enough.
But, and it is a big *but*, iron use to be difficult to remove in basic media, unless a complexing agent is in media. For that the Wallers formula...
Anyway, trying you can see what happens...
I would try directly in calcite or carbonate minerlas Wallers formula.... Say me prudent.
With best wishes
Lluís |
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