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Specialty Chemistry Forums => Citizen Chemist => Topic started by: yyttr3 on July 29, 2013, 05:25:57 AM

Title: Purification of manganese dioxide
Post by: yyttr3 on July 29, 2013, 05:25:57 AM
I've become interested in experimenting with chemistry and setting up a small lab at my house. I've extracted the carbon rods , zinc casings, and manganese dioxide from a few batteries. I've put the MnO2 through gravity filtration and I was wondering if there was any other method of purifying it. Thank you
Title: Re: Purification of manganese dioxide
Post by: yyttr3 on July 29, 2013, 05:55:08 PM
Sorry to repost but I thought of a way. Please keep in mind I've never taken a chemistry course before I'm just trying to self teach right now.

I was thinking of a process similar to separating sodium from contaminants by placing water in a bowl with mineral oil above it.

This would be similar but with hydrogen peroxide at the bottom. I know MnO2 is only a catalyst but I'm hoping it might work. I can't test me thought right now but I will the first chance I get.
Title: Re: Purification of manganese dioxide
Post by: sophotect on July 29, 2013, 09:58:49 PM
According to the wiki, MnO2 catalyzes the decomposition of hydrogen peroxide, but in your original post you said you want to purify the MnO2. Is this a single step in a multi-step process or do you just want to purify the MnO2?

MnO2 is insoluble in water, carbon & zinc more so, zinc is also a Lewis acid & could be expected to hydroxylate & thus solubize carbon, so I would think you could filter & dry aqueous solutions to wind up with successively purer concentrations, up to a point.

You can also buy relatively pure MnO2 at ceramic stores. 
Title: Re: Purification of manganese dioxide
Post by: yyttr3 on July 29, 2013, 10:45:51 PM
Then I should already have fairly pure MnO2, thank you. I'm just finding hard to figure out how pure something is. I didn't know anything about Lewis acids or hydroxylation and I did not think of the solubility of the other substances.
Title: Re: Purification of manganese dioxide
Post by: sophotect on July 29, 2013, 11:27:29 PM
It can be difficult, if not impossible, for the amateur chemist to challenge industrial grade yields. Unless you have access to good instruments, you usually have to settle for a 'good enough' separation based on the known qualities of the compound & the expected adulterants. There is always the chance of unknown or even unstated ingredients in a trade formula so never use for medications or consumption.
Title: Re: Purification of manganese dioxide
Post by: Leiem on August 26, 2013, 05:51:50 AM
I have a book. It says that β-MnO2 can be produced by heating manganese(II) nitrate hexahydrate at 150~190'C in the air.
Title: Re: Purification of manganese dioxide
Post by: billnotgatez on August 27, 2013, 01:44:10 AM
http://www.fishersci.com/ecomm/servlet/msdsproxy?productName=AC193460010&productDescription=MANGANESE%28II%29+NITRATE+TE+1KG&catNo=AC19346-0010&vendorId=VN00032119&storeId=10652

The MSDS for manganese(II) nitrate hexahydrate
states
Quote
Strong oxidizer. Contact with other material may cause a fire. Causes eye, skin, and respiratory tract irritation.
Target Organs: Respiratory system, eyes, skin.

Note
The original post was talking about extracting manganese dioxide from  batteries