Natural Metals unOxidised?

[YT2095]

One of my Hobbies is extracting metals (rare types where possible).

I did an experiment this summer whilst camping by the Sea.

I have 8 powerfull ring magnets from microwave ovens, strung together with nylon zip ties, that I then attatched to a lage rock while the Sea was out, I waited till it came in and went out again then collected my magnets,,, they were covered in manetic metal particles. When I got back home I washed it off in clean water then dried these particles (about an once), then let them sit in a flask with Hydrochloric acid. surely enough, the liquid went a golden yellow color indicative of Iron Chloride.

here`s the snag though, How is it possible that these iron filings didn`t oxidise in the sea?

we all know that salt water rusts cars and iron very quickly as it works as an oxygen ion carrier, and the sea if full of oxygen too. so they shouldn`t exist really?

 

it`s got me baffled?

[wolfson]

Chlorine changes the comples potential of Fe, so maybe the oxidization took longer, was the sample fully submerged if so then the oxidising reactant potential can take longer or stop, try fractional distillation on the substrate/solute (looking for other surfactants) or maybe an experiment of FeCl submerged for 3 days in sea water solution to see what occurs...gl

[YT2095]

well the product that my magnets picked up were mainly (about 95%) Iron.

this was obtained as particulate matter in ranging sizes from micro to sand sized grains.

 

my question is largely based upon how this can be possible? surely the Sea water would have "rusted" all these?

and where did they come from in the 1`st place?

 

 

 

seriously try this for yourself next time at a beach, get a small magnet and in a little pool (rock pool even) dig up a few handfulls of "sand" under water and let it fall over yer magnet, you`ll find magnetic particles adhere to it

 

 

[aman]

Maybe you could try a control experiment with pure Iron filings you've produced poured into seawater. See if they rust over time

Just aman

[wolfson]

Yes that wold be ideal to see if the potential was changed by the submerged Fe in Salt Water solution

[VendingMenace]

YT, i may be able to help out some here. DO you know what Iron Chloride this is?

 

If memory serves, some of the Iron chloride comlexes are actually three dimensional matrixes. Each iron has 6 Chlorides attached to it, and some of the chlorides (i think three) serve are bridging ligands to other iron centers. Thus, the irons are all sharing chlorides. Because the chlorides are contained in an matrix it is much harder for them to exchange with potienial ligands in teh environment (including oxygen). Thus, they are given additional stability (iron complexes are usaully quite labile) beyond the little they normally have. This could be the answer to your question.

 

Of course there could be others. It may just happen that chlorine is more stabalizing or a ligand than is oxygen. (though i doubt that this is a major cause). As such, once iron binds cholrine it is less likely to switch for an oxygen. But i must stress this is most liekly not the case, as i said earlier iron is quite labile.

 

hmmm...it is an interesting question. I would imagine that it has to do with the 3-D structure of the complex. But of course i would have to know what iron chloride it is to be sure. Anyways, yeah.

 

 

One last thing. you sai above...

How is it possible that these iron filings didn`t oxidise in the sea?

 

Well, the iron in iron chloride is oxidized. The word oxidized does not nessessarily mean "combined with oxygen." It can also reffer to the number of electrons that an atom currently has as compaired to the number it has in its elemental form. Thus, an atom that has 2 less electrons than in its elemental form carries a charge of +2 and, similarely, we say that it is in a +2 oxidation state. If an atom has more electrons than it does in its elemental form, then we assign it a negative oxidation state. For convienince we call atoms that have positive oxidation states "oxidized" and ones that have negative oxidation states "reduced".

 

In a neutral iron cholride complex, we know that each chloride has an oxidation state of -1 so the iron nessesarily has a positive oxidaton state. SO we find that in a iron chloride complex, the iron is indeed oxidized.

 

 

I am not sure whether you knew this or not, so i thought i would err on the side of telling you things you already konw, instead of letting you live in ignorace. Please do not take my telling you this as an insult if you already know. I just thought that if you didn't know this you would like to know. Thats all.

[YT2095]

LOL, non taken, and yes I was aware about oxidation. I meant it quite literaly. they hadn`t been oxidised as in they`re still metalic particles and unaffected (somehow).

the iron chloride obtained was the FeCl3 variety, with FeCl2 traces.

roughly 80:20 ratio (or 4:1 if ya wanna be fussy LOL).

I`ve performed a simple displacement reaction and obtained a purer version of the original metalic particles.

but no such luck yet as to obtaining the Cobalt metal I was after originaly. darn pity they have the same displacement factor.

cheerz anyway guys, if I find a way, You`ll all be the second to know

[Pleiades]

I’m a bit late but lemme take a crack at it. Magnetite, Fe3O4, is a very common compound found in sand in many parts of the world. I was not aware that any of iron’s other compounds were very magnetic. Magnetite is a black solid that tends to come in little grains, apparently it contains both FeII and FeIII, so the acid/base analysis tests may give you some strange colored results. All this business of chloride confuses me; wouldn’t most iron compounds be displaced into iron chlorides when put in HCl?

[YT2095]

it did make iron chloride(s), and the color was (is) a yellow orange liquid. and yes when placed in my magnetic "bottle" and displaced hith Alu foil, it gave pure iron as a result

 

Magnetite as small grain, black compound found in sand, is exactly what it looked like (although there were some propper metalic parts) is the answer is was looking for

 

Cheerz

[Pleiades]

I was pretty sure it was magnetite, good to know I got it right, the past 2 popular science How2.O columns; July and August, have mentioned it. Now, I could make thermite if only I could find a good source of powdered aluminum, cause ball milling takes weeks.

[jowrose]

Yeah, I have recently been experimenting in the fun world of thermite. Bought some aluminum powder and iron oxide on the internet (not as fun as making it all, i know, but i didn't feel like taking a month to make enough rust; tried that before, was a wee bit too frustrating... ). I used magnesium ribbon to light it, and i could get the thermite to light on the first try, every time. I put a piece of solid steel along with the mixture and in about 15 seconds it was liquified. Amazing stuff, that thermite.

 

I have also heard that Fe3O4 was a more stable replacement to the Fe2O3 commonly used in the thermite reaction; it also seems like a more practical solution as it is more easily obtained (in my opinion). However, I have also heard reports of it actually burning hotter than rust thermite. Chemically, does that make sense? Would more energy be released with the splitting of more elements in the compound? I must admite my knowledge of chemistry is somewhat minimal, I plan on taking it this year in high school and going for the AP class senior year. It all just fascinates me. Well, anyways, I am planning on heading out to lake michigan tomorrow, so i'll bring some powerful magnets and see if i can pick myself up a coupla pounds of magnetite. I'll post again in a coupla days with the results of my venture.

[Externet]

Can you discern if the black sand picked is not Ti binding with Fe?

It's one of those things heard as a kid; the local portland cement factory uses black sand collected from beaches as part of the recipe to improve the clinker.

Miguel

[YT2095]

IIRC, "Black sand" is actualy a lucky find! many prospectors seek this as it`s frequently rich in Gold deposits

[Externet]

This black sand at a Pacific seashore (not on fresh water rivers) is highly abundant, but has never been tied with precious metals. But its titanium content is large, as heard from knowledgeable people.

A good way to magnetically pick soils is by putting the magnets at the bottom of a plastic bag, and removing the bag to collect, the material falls off leaving the magnet clean.

Surprisingly, if you look closely with magnifier, many transparent grains of sand are equally attracted by the magnet.

Don't know if differs from the black sand composition found on gold bearing areas.

Miguel

[Tetrahedrite]

IIRC, "Black sand" is actualy a lucky find! many prospectors seek this as it`s frequently rich in Gold deposits

Absolutely correct. Magnetite is formed in high temperature, hydrothermal systems. These systems often contain gold and other valuable metals such as tin, tungsten, moly and PGE's.

 

When gold panning in a creek or stream, often the last phase of the process is removing the residual magnetite with a magnet to hopefully leave your gold nuggets!

[Thomas Kirby]

Some oxides of iron are magnetic. Magnetite can be created by bacteria or chemical action.

[Crazy4It2]

I noted several references to FeCl3 but none to FeCl2.

 

I have a need for FeCl2 and have no idea how to synthesize it, if it differs from that already mentioned...which from what I gathered does not create FeCL2.

 

Frankly I have no idea what the difference is other than that mentioned already which I don't readily assimilate.

 

My purpose is the precipitation of gold from AquaRegia, which according to the process I have found requires FeCl2.