actually I already try for made that with precipitate methode combine FeSO4 with excess Na2CO3 and wash with that Na2Co3 and water but the result still dark green and after dried become black. I want that compound white.. thanks..
https://pubchem.ncbi.nlm.nih.gov/compound/ferrous_carbonate
https://en.wikipedia.org/wiki/Iron(II)_carbonate
Why excess Na2CO3? (pH !!)
"Care must be taken to exclude oxygen O2 from the solutions, because the Fe2+ ion is easily oxidized to Fe3+, especially at pH above 6.0."
Freeze drying?
I dont know, I just follow this patent http://www.google.com/patents/US20150267132 maybe they use that excess for made the precipitate, no.. I just dried that result after washing on ordinary oven.. and it become black and react with magnet I think it become FeO or Fe3O4..
Patents are often written without exact know-how. Excess FeSO4 maybe better, and slightly acidic pH is important, washing with pure water (and finally, possibly with methanol), and no oxygen.
Oh actually maybe I will give up with this method and change use hydrothermal from this paper http://pubs.acs.org/doi/abs/10.1021/cg060459q, just mix Fecl3.3H2O solution and Na2CO3 solution and hydrothermal 160 C 3 h, but still afraid with the result color because FeCl3.3H2O maybe will produce brown color, and I want white. If I can chang that FeCl3.3H2O to become FeSO4.7H2O it would be great because the color of that FeSO4 almost white than FeCl3
You can combine the methods and prep. from FeSO4 with some ascorbic acid to prevent the oxidation of Fe(II) to Fe(III), but the pH and exclude oxygen is important. And final washing with alcohol ... And "were dried at 50 °C under a vacuum oven for 12 h".
Oh yeah maybe it work, but maybe I not using AA because I'm not have it but if I read that paper AA is just for morphology so maybe no problem if I not use that, is that right? and yeah must dried at vacuum for not oxidation. And why with alcohol? not ethanol?
Maybe it works without AA, but I think - you must use FeSO4 excess instead of Na2CO3 excess. And perhaps some CO2 to the washing water. Ethanol or methanol both good - to remove water and lowering the drying temperature (because during drying, water + oxygen + heating = oxidation of Fe2+).
oh... so maybe I just wash with Ethanol not with water.. ok ok ok, thanks for your advice and can I ask your email? maybe if there is some problem I still can discuss with you haha...
First wash it with water (some CO2 in it) to remove excess FeSO4 and Na2SO4.
You find my e-mail addr. here: http://padre.uw.hu/index.html
Oh ok thanks... and I want to ask you about characteristic of that Fe 2+, is all of Fe 2+ if in room state is easly to become fe 3+ ?
Fe(II) compounds must store dry and well closed.
(But are some stable -> Siderite)
http://www.minerals.net/mineral/siderite.aspx
https://www.mindat.org/min-3647.html
https://en.wikipedia.org/wiki/Siderite
oh sir, actually have you ever take NIR measurement for FeCO3?
No. But there was crystalline siderite (about 20-30 g) in my hand, with a colour similar the honey.
oh... do you have NIR machine on there? because I just want to make sure of absorbance of FeCO3 at 900-1100 nm is good or not. because I still search Fe material with smooth color not black or dark or brown and have good absorbance at 900-1100 nm for laser material
ok ok thanks a lot sir, maybe if you finished for the NIR, can you inform me from this web or email me at [email protected] about the result of absorbance at NIR
Some literature:
http://www.asdi.com/getmedia/555ae1ce-a0b3-4850-b521-7e33ed09df19/Use-of-NIR-Spectroscopy-in-Mineral-Identification-of-Shale.pdf
http://www.minproc.pwr.wroc.pl/journal/pdf/ppmp52-2.620-633.pdf
https://www.researchgate.net/publication/294535420
http://rruff.info/Siderite/R050349
http://rruff.info/Siderite
Article Qualitative identification of copper bearing minerals using ...
Oh thanks for the literature, but all of them just check of reflectance from NIR and I want to know the absorbance..
https://www.researchgate.net/post/Does_anyone_know_a_good_and_free_online_database_of_IR_spectra
http://www.stjapan-usa.com/
ok ok I will search on that website, thank sir, very helpfully for my next work for search right compound with good absorbance at 900-1100nm.
https://www.researchgate.net/publication/316889678_Hydrothermal_synthesis_of_siderite_nano-particles_and_characterizations
Conference Paper Hydrothermal synthesis of siderite nano-particles and charac...
Hello Maulana,
Pannonian Uniform Lithospheric Infrared Spectral Database
It`s (perhaps) free, but need register, and perhaps you will find IR (NIR ??) spectra of siderite.
http://puli.mfgi.hu/
(From: https://www.mfgi.hu/hu/adatbazisok )