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plante1999
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i think you must go to the dollar store and buy spoon , it is cheap and you wont scrap something that is interessing. ammonium hydroxide make a good
test , if nikel is present a green prec. form and it disolve in exec ammonia , you will get a distinctive pink color. if no nikel is present , you
sould see nothing , but befor peforming this test ad small amount of H2O2 for oxidising compound II to III.
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plante1999
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sorry for the double post.
finnaly no-iron chromium compound.
procedure:
3spoon disolved in 100ml 31%HCl .
than boil the solution to get the calcined oxide.
than take a ss beaker and ad green crystal drano, melt the mixture at 600-800 for 15minute.
disolve the chromite in water , ad small amount of zinc chloride (((catalist)a yellow precipitate form) chrome yellow) than ad HCl and you have green
chromium III chloride.
picture for later.....
[Edited on 30-3-2011 by plante1999]
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cyanureeves
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what would they use instead of steel? or iron and make it cheap?zinc? you have to melt the drano?anyway dichromate in solution with a little sulfuric
acid and using a lead anode will leave a wonderful yellow crossedge pattern on metal.just like you see on the inside of a new tin can. it's not what i
was after but after seeing this i was not dissapointed.next time i'll look you up for metal composite instead of google.this was like c.s.i.
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plante1999
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finnaly i decided to make a large amount of zinc chromate with my zinc chloride solution. i precipitate it and than wash it with ammonia , i think it
is very pure and , can i use zinc chromate to make chromium , via thermite reaction.
it is probably made of aluminium or zinc with a brass plating.
3 ZnCrO4 + 8 Al === > 3 Zn + 3 Cr + 4 Al2O3
i think it will probably need an oxidizer.
no battery for making picture , sorry.
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
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plante1999
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photo!
finally whe have done!!!
first , the beaker with the rust residu . the filter paper with zinc chromate . erlenmeyer with ammonia and chromium hydroxide , my test tube for
precipitation and finnaly , the spoon. I think an improuvement is to precipitate lead chromate and than add HCl to the dry product to make nearly
insolube lead chloride and chromium III chloride.
check my homemade clamp !!
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
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plante1999
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Extraction of lead chromate from 18/0 Stainless steel
by plante1999
First this is a guide for extration of a realy pur chromium compond for futur prossesing , the lead chromate produced can be aded to 0 degree celcius
31% hydrochloric acid to precipitate lead chloride and keep in solution chromium III chloride. Picture will be aded later.this is a prepublication of
the futur prepublictation that i eill post on prepublication forum.
Warning: Hydrochloric acid is corrosive to the skin , the fume are toxic and corrosive. Molten sodium hydroxide is incredibly corrosive lead chromate
is probably a cancerigen.
Part:1 Lead Acetate
For this part you will need:
Lead metal , can be found at the scrap yard
copper acetate , different way of synthesis include : copper carbonate + vinegar (acetic acid) or cleaning vinegar(10% acetic acid) + hydrogen
peroxide + copper.
800ml beaker
hot plate
filter paper
funnel
erlenmeyer for filtering
Take an exes of lead and ad it to a 800ml beaker with 500ml of 10% copper acetate solution. After a certain amount of time the lead will react and
form lead acetate.
This is the equation:
Pb + Cu(C2H3O2)2 → Pb(C2H3O2)2 + Cu
Filter the solution. You have around 10% solution , boil it to 120ml. Lets the solution hot for one of the last step. Repeat this 3 time.
Part:2 Make the oxide of the 18/0 Stainless
First you need to get Stainless steel spoon from the dollar store. This type of spoon is alway 18/0 stainless steel , 18% chromium , 0% nickel and 82%
iron.
I have found 2 way to make the oxide , here a resume of each way:
Way:1 disolve spoons in hot Hcl and boil the solution to get the calcined oxide.
Way:2 electrolisis of the spoon in NaCl solution and boil the solution to get the oxide.
Way:1 Disolving in HCl
You will need:
3x166ml of 31% Hcl
250ml beaker
3 spoon or 105g of 18/0 Stainless
Hot plate
Fist take 166ml of 31% HCl per 35g of Stainless steel (use 105g of stainless) Heat the HCl to boiling in glass beaker and ad the stainless. 2 reaction
take place at the same time.
Fe + 2HCl -> FeCl2 + H2
2Cr + 6HCl -> 2CrCl3 + 3H2
After most of the Stainless eacted , boil the solution in a Stainless beaker to get the calcined oxide. Lets it hot for the next step.
Way :2 The electrolisis
You will need:
A 12Volts 15amps power supply
400ml of 5% NaCl solution
3 spoon or 105g of 18/0 Stainless
Hot plate
Take 400ml of 5% NaCl solution and electrolise the spoon as an anode in a steel beaker that is use as an cathode. After certain amount of time the
hydroxide will precipitate , this way have an adventage , but falloig this guide you need to disolve 105 g of 18/0 stainless, you could disolve the
amount of spoon you want. When it is done boil the solution to get the calcined oxide. Lets it hot for the next step.
Part:3 Make sodium chromate
You will need green crystal drano. Ad 70g drano to the mixed oxide made in the part 2 per 105g of Stainless and heat with a blow torch to melt the
hydroxide with the chromium oxide , mix it with a Stainless spoon. Stop after 15-20min the heating.
This reaction take place :
Cr2O3 + 4NaOH + 3NaNO3 -> 2Na2CrO4 + 3NaNO2 + 2H2O
Part:4 Make Lead chromate
You will need :
100ml of distill water
2x500ml beaker
300ml of hot acetate solution
The melt from the part:3
2 filter paper
Buchner funnel
Vacuum pomp
500ml buchner funnel
3-5% ammonia solution
Digest the melt in 100ml of distill water for 12hour. Now filter it in 500ml beaker , you will get yellow sodium chromate solution. Per 105g of
Stainless ad 300ml of the hot lead acetate solution.
This is the equation of the reaction :
Pb(C2H3O2)2 + Na2CrO4 -> PbCrO4 + 2Na(C2H3O2)
A heavy yellow precipitate form, vaccum filter it and wash it with dilutew ammonia.
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
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blogfast25
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Quote: Originally posted by plante1999  |
i think it is very pure and , can i use zinc chromate to make chromium , via thermite reaction.
it is probably made of aluminium or zinc with a brass plating.
4Al + 3ZnCrO4 -> 2Al2O3 + 3Zn + 3Cr
i think it will probably need an oxidizer.
no battery for making picture , sorry.
[Edited on 30-3-2011 by plante1999] |
Oxidiser?? What do you think ZnCrO4 is, huh?
But using Zn chromate will mean you’re making an alloy of Zn and Cr, not pure Cr:
ZnCrO4 + 8/3 Al === > Zn + Cr + 4/3 Al2O3 is correctly balanced (yours isn’t). Multiply both sides with 3 if you don’t like fractions (LOL):
3 ZnCrO4 + 8 Al === > 3 Zn + 3 Cr + 4 Al2O3
When you got the sodium chromite, why not carefully neutralise to pH ≈ 7? Cr(OH)3.nH2O drops out. Filter, wash and dry (semi-calcine) to Cr2O3.
Then Cr2O3 + 2 Al === > 2 Cr + Al2O3
Industrially, aluminothermic reduction of Chromite ore is used to produce ferrochomium:
FeCr2O4 + 8/3 Al === > Fe + 2Cr + 4/3 Al2O3.
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plante1999
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in fact i think the zinc will volatilise. and i already tested the ph 7 but it doesn work for my. Probably because i have no chromite but chromate ,
because of the 25%NaNO3
[Edited on 30-3-2011 by plante1999]
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cyanureeves
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excuse me plante1999. in step #3 where does the chromate come from? the spoon used to stir or the s.steal container in which you melted it? or did i
miss a step? if 18% chromium and 82% iron were 18% nickel and 82% iron,wouldn't that be good quality s.steel? go for chromium metal now!unless you got
to do all that dry calcium burning stuff you googled.
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plante1999
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when drano is added to the beaker it melt and react with the chromium oxide in the mixed oxide of iron and chromium to make the chromate.
This reaction take place :
Cr2O3 + 4NaOH + 3NaNO3 -> 2Na2CrO4 + 3NaNO2 + 2H2O
cheap stainless contain 18% chromium 0%nickel and 82% of iron.
the guide is edited.
[Edited on 30-3-2011 by plante1999]
[Edited on 30-3-2011 by plante1999]
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cyanureeves
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the oxide step is very short in detail and i overlooked it even though its the most important. sorry about the 18% nickel crap i said. i used to work
with s.steel sheets alot and all this time i thought nickel was a bigger component than chromium in s.steel. you use the term calcined, does that mean
cooked dry after evaporation or will just evaporation do?the term calcined is used alot in chemistry lit and so is dry over and passed through. as
passed through a stream of hot charcoals.confusing terms!by the way lead in vinegar will bleed white lead acetate too wont it?but it will take longer
i bet. cool work man.
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plante1999
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when i said calcined i want to said heated on a hotplate to decompose the chloride or the hydroxide tho the oxide , like you said it need to be cooked
, evaporation wont decompose the chloride to the oxide and hydroxide will take a long time. Lead in vinegar take so long time that it is not usefull.
Thanks!!!
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blogfast25
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| Quote: Originally posted by plante1999 | in fact i think the zinc will volatilise. and i already tested the ph 7 but it doesn work for my. Probably because i have no chromite but chromate ,
because of the 25%NaNO3
[Edited on 30-3-2011 by plante1999] |
Yes, my bad, chromate needs to be reduced first to chromite, of course.
ZnCrO4 thermite is likely to near-explosive, possibly flash powder. You MUST use Cr2O3.
By calcining here i mean heatinng to 500 C or more, so not 'proper'calcination (1000 C and above)
[Edited on 31-3-2011 by blogfast25]
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Magpie
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I like your clamp. Did you use a coat hanger?
I have just made a nickel crucible/liquid metal bath assembly from a Mr Bartender cocktail shaker. But I'm not ready to show it off yet.
The single most important condition for a successful synthesis is good mixing - Nicodem
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blogfast25
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Yeah, the clamp is good, very professionally looking! But I doubt if coat hanger wire would be rigid enough. And how is it attached to the lab stand?
A broad and fairly crude estimate of the reaction enthalpy for the aluminothermic reduction or ZnCrO4 with Al came out as somewhere in the region of -
800 to - 850 kJ/mol of Cr produced. For the reduction of Cr2O3 the value is - 270 kJ/mol of Cr produced. A whopping difference!
[Edited on 1-4-2011 by blogfast25]
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blogfast25
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About 6 mmol (expressed as [Cr3+]) of blue-green chromium [III] oxide hydrate in a large test tube:
Obtained as a by-product of oxidising K2Cr2O7 with methylated spirits.
3 chromium metal nuggets (11.2 g), obtained from Cr2O3 thermite (and a 1 p coin):
[Edited on 3-4-2011 by blogfast25]
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plante1999
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| Quote: Originally posted by blogfast25 | Yeah, the clamp is good, very professionally looking! But I doubt if coat hanger wire would be rigid enough. And how is it attached to the lab stand?
[Edited on 1-4-2011 by blogfast25] |
thanks! it is made from large coat hanger plated nickel wire.
it is attached be 2 stainless steel bolt.
nice chromium from the oxide!
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plante1999
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does methanol work for oxidising ammonium or sodium dichromate?
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blogfast25
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You mean reducing (Cr [+VI] === > Cr [+III])? Yes. All primary alcohols are oxidised to their carboxylic acids, all secondary alcohols to their
ketones... Methanol works to reduce dichromate to Cr [+III].
Strangely enough, in acid conditions dichromate can also oxidise H2O2 to water. So, in alkaline conditions H2O2 is an oxidiser for Cr3+, in acid
conditions Cr2O7 (2-) oxidises H2O2 to H2O!
[Edited on 6-4-2011 by blogfast25]
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Lambda-Eyde
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I'd use isopropanol in place of methanol, as both methanol and formic acid are toxic and not exactly fun to handle. Acetone, on the other hand, is a
walk in the park.
This just in: 95,5 % of the world population lives outside the USA
You should really listen to ABBAPlease drop by our IRC channel: #sciencemadness @ irc.efnet.org
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blogfast25
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| Quote: Originally posted by Lambda-Eyde | | I'd use isopropanol in place of methanol, as both methanol and formic acid are toxic and not exactly fun to handle. Acetone, on the other hand, is a
walk in the park. |
Both methanol and formic acid really are of quite low toxicity: avoid spills, imgestion and wash your hands on contact. I've seen formic acid being
used in kettle descaler sachets.
[Edited on 6-4-2011 by blogfast25]
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ScienceSquirrel
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The standard reagent for making chrome alum from potassium dichromate is sulphuric acid and methylated spirits.
I have done it and it works really well, the other product is mainly acetaldehyde.
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plante1999
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2 CrCl3 + Cr → 3CrCl2 , does anyone can test if it work? i think the iron cannot react because it is more noble than chromium, some patent said
for extract iron from ore to conssentrate the use of FeCl3 is good.
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blogfast25
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| Quote: Originally posted by plante1999 | | 2 CrCl3 + Cr → 3CrCl2 , does anyone can test if it work? i think the iron cannot react because it is more noble than chromium, some patent said
for extract iron from ore to conssentrate the use of FeCl3 is good. |
Check the reduction potentials for Cr3+ == > Cr2+ and Cr(0) == > Cr3+. Add Ered + Eox. If Ered + Eox > 0 the reaction can proceed...
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cyanureeves
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plante1999 you did very well with chromium extraction and i think you would have been useful in the nickel from cupro-nickel extraction thread. that
thread has many methods but i dont know if all were actually done because alot of theory was in place.The belt buckle i dissolved turned out to be
cupro-nickel i dont know why i forgot about that s.steel looking alloy.electrolyzing and plating out the copper onto the annode is the best i could
do.nichrome wire has a bit of chrome in it,i took some from inside of heating coil. i electrolyzed some in sulfuric acid solution and some in hcl
solution and dont understand why i cant seperate nickel solution from chromium by adding sodium hydroxide. i thought i would get insoluble nickel
hydroxide and chromium in solution but it all precipitates as a black cloud.both also go into carbonate together and when turned into acetate it turns
red(chromium acetate?)by the way nichrome wire made a great nickel anode for nickel plating. i electrolyzed some nichrome wire in sodium carbonate for
three solid days i got a yellow solution and a bit of orange precipitate but spilled that solution. all was not lost because the acetate solution
mixed well with my homemade nickel watts plating bath. which consists of nickel sulfate, nickel chloride and boric acid and now nickel acetate. i
cant believe canadians used solid nickel in coins, so it is common to find these coins in circulation still isnt it?
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