Cut some of the Lead in 2*2 cm squares and place these in a glass heat resistant bowl with a loose lid. Some Nitric acid (53%) is added. Then the bowl is heated. Lot's of brown NO2 gas evolve when the Lead dissolves. White crystals form since it doesn't all dissolve. Try to keep it just below the boiling point. From time to time water is added to make up for what has evaporated. When NO2 is formed no longer the excess lead is picked out of the solution with large tweezers. Then the solution is boiled, and water is added in small amounts until all the white crystals have dissolved plus a little extra. (Bigger container needed.) Then the solution is allowed to cool.This will yield Lead Nitrate crystals. They are octahedral but look like triangles when they form on the bottom of the container (an octaeder lying on one face has a triangular upper face). That last recrystallisation step is necessary because the roof covering is actually an alloy. The main hazards of this are (besides hot, corrosive liquid etc): 1. the NO2 gas that evolves. It attacks your lungs and is poisonous. Do this outside and only in a breeze. Stand upwind. The other problem is the mist of droplets that forms because of the bubbling. You can't see it and it's extremely important that you don't even inhale tiny amounts. The Lead accumulates and will affect your nervous system. So don't omit the lid on the container and again, stand upwind. You are probably aware of this (the plating cells have the same problem) but it wont hurt to warn you anyway.
Lead Nitrate
Lead Nitrate is the most soluble Lead salt (55g/100g water), and is a popular choice for a plating bath when making PbO2 anodes. The following procedure was described briefly by "tentacles" in one of the anode making threads. The method is very useful as it does not require Nitric acid. The procedure is essentially the "Nitrate" version of the Copper Carbonate / Acetic acid method described by "MadHatter" earlier in this thread for producing Lead Acetate in that Pb is brought into solution by electrochemical replacement by Cu.
After a few initial hiccups, I found this Nitrate method to be both cheap, safe, elegant and relatively simple.
The method is based on making Copper Nitrate from two cheap and easily obtained agricultural chemicals (Calcium Nitrate and Copper Sulphate) and then reacting the Copper Nitrate with Pb metal, to form Lead Nitrate.
2) Cu(NO3)2 (187.6g) + Pb (207.2g) ---> Pb(NO3)2 (331.2g) + Cu
Equation 1 is a metathesis reaction in which CaSO4 is precipitated, and is a useful procedure for producing many different Nitrates. Unfortunately it can be difficult for the amateur as the CaSO4 precipitate is particularly thick and it can be difficult to separate from the desired Nitrate solution. In this situation, a vacuum or pressure filtration system is needed if one wants to work at reasonable concentrations. If you do not have adequate filtration, it may be possible to do this in a stepwise fashion at lower concentrations. Ensure that you have the correct starting material, do not use Calcium Ammonium Nitrate (CAN) as this is an Ammonium Nitrate - Calcium Carbonate mix.
Remember blue Copper Sulphate is in the form of the pentahydrate, so you will require 1.56 times the stoichiometric amount in equation 1. Use a slight excess of Ca(NO3)2 and remember that CaSO4 has slight but appreciable solubility (.21g/100g) some of this can be removed by concentrating the Cu(NO3)2 solution and cooling to 0 oC. The CaSO4 will crystallise out as very fine short aciculate crystals. If it is not removed it will react with the Pb++ to form insoluble PbSO4.
Once you have obtained your blue Cu(NO3)2 solution, place it in a beaker and hang excess strips of brushed and cleaned Lead sheet in the solution. Shot or other forms of Pb could be used, but may need stirring from time to time. Immediately, any shiny Pb surfaces will turn brown, after a minute or so, when a strip is removed, shiny specks of Cu will be seen, these may turn brown within a few seconds of being removed from the solution. After several minutes, a distinct plating of Cu will be observed on the Pb sheet, and it will become corroded as it goes into solution.
Leave the reaction to proceed for 24 hours in a ventilated place (some nitrogen oxides are produced). After this time all reactions should have ceased and the solution will be a very pale green colour. Filter out all the debris and insoluble material, add a few drops of Nitric acid, concentrate by boiling and allow to cool slowly to 0C. The Pb(NO3)2 crystallises out as snow white, well formed, octahedral crystals.
Litharge can be bought from ceramic supply stores.
If you have access to Lead Hydroxide or Basic Lead Carbonate(white lead) or Lead Carbonate then you can easily react it with Nitric acid to make Lead Nitrate.
If you have access to Red Lead (Pb3O4), also called Lead Tetroxide or Minium or Lead Orthoplumbite you can make Lead Nitrate. You need nitric acid
Into a beaker put some dilute Nitric acid and warm it. By means of a spatula, add Red
Lead a little at a time. Care must be taken not to add too much at a time or it will
contaminate the product. As the Red Lead is added a brown powder, Lead Dioxide, will ppt and Lead
Nitrate is formed in solution.
Pb3O4 + 4HNO3 ~~~> PbO2 + 2H2O + 2PB(NO3)2
Lead Carbonate You can make (pretty) pure PbCO3. From that, you can easily make some Lead Acetate with vinegar (or cleaning quality (=more concentrated) Acetic acid). I have not tried this exact procedure, but I use a similar procedure to purify my Lead foil. I start with Nitric acid instead, and the rest is the same as what I do to purify the Lead. I eventually convert the Carbonate to Nitrate with Nitric acid but if you have no Nitric acid I suppose you can use Acetic acid. If the dissolving part works, the rest will be a piece of cake. It only takes some time, but I am sure it will work just fine.
You will need:
Muriatic acid HCl
NaNO3
Lead/Tin mix
Sodium Carbonate
First, take some Muriatic acid, and dilute this to make a 10%
Hydrochloric acid solution.
In a liter of this solution, dissolve 244.7 grams of NaNO3 by heating
the solution. Watch
out for HCl fumes! They can ruin your lungs. At least for a while. When
the NaNO3 has
dissolved, don't stop heating.
Add 298 grams of your Pb/Sn mixture which you previously cut into as
many small
pieces as possible. Brown gas will evolve. This is NO2, and it's
something to watch out
for. It attacks the lungs (like HCl).[IT WILL GOOSE (KILL) YOU]
Stir every once in a while and keep the solution hot. The Lead/Tin will
dissolve and pretty
soon the solution will be saturated with PbCl2. It will crystallise.
Keep heating and
stirring the solution as long as the NO2 evolves. Dissolving Lead foil
in Nitric acid takes
me half an hour. It will take you somewhat longer, since the solution is
less concentrated.
Add some water every once in a while to make up for what has evaporated.
When the reaction has ended, let the solution cool to room temperature.
Then cool the
solution further to about 0 deg. C. Filter to obtain raw PbCl2.
Recrystallise this PbCl2 from a boiling saturated solution (cool it to 0
deg C to increase
the yield). This should produce pretty pure PbCl2.
Now, weigh the PbCl2 (You do not have to dry it first). Place the PbCl2
in a container
and to every 100 grams of PbCl2 add 50 grams of Sodium Carbonate. Add
300 ml's of
water (or more if it doesn't seem enough) and boil the mixture for about
15 minutes. Stir
well. Then, let the PbCO3 that has formed settle and decant the liquid.
Add 300 ml's of
fresh water and boil again. Let settle, decant and repeat one more time.
This should
remove any Na2CO3 that is left in the PbCO3.(lead carbonate)
The bicarbonate will work fine instead of carbonate. So will NaOH (but then you must make sure you don't add too much NaOH. If you do it will redissolve the lead hydroxide/oxide formed). Potassium salts can also be used if they are easier to find.
If NaCl ppt's you can always add a little extra water to redissolve it. That will only slow down the reaction between the Lead/Tin alloy and the NaNO3 in HCl solution a little.
The Sn dissolves. I don't know what that grey silt is exactly. That depends on so many factors (concentrations, temperature, pH). I guess you can filter it and use it. The Lead will be extracted if there is any in there.
The Tin dissolves, but won't precipitate. SnCl2 is quite soluble. PbCl2 is not , and this is what separates the Tin from the Lead. The Tin stays in solution and the PbCl2 crystallises.
The additional recrystallisation of the obtained PbCl2 below will purify the Lead further removing almost all the Tin that may be left
Will NaCl ppt? 39g/100ml @100C or 300 ml will hold 117g NaCl. I guess
there isn't that much there.
Indeed. There is 11.6 g NaCl per 100 ml of solution.
But even if the NaCl does precipitate it will be removed in the next step: the repeat washing of the precipitated PbCO3 with boiling water. That is supposed to remove any Na2CO3 left, but it will also remove the NaCl that may be left.
You now have pure PbCO3.
Make this into any Lead salt you need by adding the corresponding acid.
For instance, use
Acetic acid to make Lead Acetate, use Nitric acid to make Lead Nitrate,
Sulfuric-->Sulfate.
You can also make Lead Carbonate from the following recipe from an old book.
Two lead electrodes are put into a solution of sodium chlorate (15g) and sodium carbonate (5g) in about one liter of water. A DC voltage is applied to the cell and carbon dioxide gas is bubbled into the solution where clouds of Lead Carbonate are produced.
The Carbonate is washed and ready for use. Make sure there are NO CHLORIDES in the Sodium Chlorate that is used or if there is, make sure there are NO CHLORIDES in the finished product. Carbon dioxide can be generated using marble chips (builders suppliers) and a dilute solution of H2SO4 (car battery acid).
Pb --> Pb2+ + 2e-
Pb2+ + 2CH3COO- ---> Pb(CH3COO)2
3Pb(CH3COO)2 + 4NaC03 + 2H20 ---> 2PbCO3.Pb(OH)2 + 2NaHCO3 + 6CH3COONa
The process was operated by Anaconda White Lead Products, until abandoned because of
loss of markets, to give 26.4 tons/day. A full description of plant and process in ref.
82.
All white Lead manufactured was used as a pigment. The outstanding characteristics of
that produced electrolytically were its exceptional purity (only lead being dissolved in
the cell), uniformity, and brilliant whiteness.
81: E. W. Sperry, Brit. Pat.,144,819 (1919); US Pat., 1,452,620 (1922).
82: R. G. Bowman, Trans. AIME, 73 (1926) 146
The process is described in US Patent 1,308,948
Most of the above procedures are from people the author of this page has had conversation with.