[Terry Gallentine]

As per another conversation in this forum, I have been attempting to increase the Ph of metal salt solutions that I use in my glasswork.  First I made up a close to saturated solution of cobalt (II) chloride then I tried to increase it's Ph by adding it to some 50% ammonium hydroxide solution.  Initially I added it in stages until the Ph was up to 6.3 (it started out at 3.3).  The result was that the solution clouded and increased in viscosity.  I then tried adding the same amounts of cobalt (II) chloride into the ammonium hydroxide solution in one step.  I got the same clouding and thickening.
I assume that this clouding and thickening is indicative of the salts falling out of solution.  Is this so?  I am now waiting to see if the solution will clear or thin with a little time.
Does anyone out there have any suggestions or techniques for mixing these two without the getting this clouding and thickening effect?

[Tetrahedrite]

Yes, the clouding is almost certainly due to the formation of very finely disseminated Co(OH)2 precipitate, possible as a colloidal solution which would explain the thickening. As I explained before (although everyone seemed to disagree) almost anything you use to increase the pH of the solution will decrease the solubility of the cobalt, causing the formation of hydroxides and/or oxides. There may be some complexing ligands that are stable at neutral pH's but these will probably be expensive.
How does the solution have to be delivered? Is it possible to deliver it as a colliod? If the low pH is a big problem maybe another solution (pardon the pun) to the problem needs to be found. With a quick browse over the internet I found that cobalt bases chemicals are often used in the printing industry, maybe one of these will be appropriate for what you are attempting to do

[Terry Gallentine]

Thanks for the response.  I have been observing settling of the solution during the last couple of days.  A clear solution seems to be on the top and a colloidal solution on the bottom.  The clear solution on the top tests out at a Ph that I was shooting for (6.5) and there is cobalt present in it but I do not know how much.  The colloidal solution on the bottom seems to remain freely soluble but I need to know that it will not continue it's settling process.  I need to know that it will not continue settling for it to be used in it's required delivery system (which is delivery by inkjet).

Is there a way to accelerate the settling process of this material?

[billnotgatez]

From this site <<http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA4/MAIN/COCL/PAGE1.HTM>>>

Aqueous Reactions: Cobalt(II) Chloride
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cobalt(II) chloride (CoCl2) is added to barium chloride (BaCl2). The result is no visible reaction.
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barium chloride (BaCl2) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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copper(II) nitrate (Cu(NO3)2) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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cobalt(II) chloride (CoCl2) is added to copper(II) nitrate (Cu(NO3)2). The result is no visible reaction.
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copper(II) sulfate (CuSO4) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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cobalt(II) chloride (CoCl2) is added to copper(II) sulfate (CuSO4). The result is no visible reaction.
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sulfuric acid (H2SO4) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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cobalt(II) chloride (CoCl2) is added to sulfuric acid (H2SO4). The result is no visible reaction.
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hydrochloric acid (HCl) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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cobalt(II) chloride (CoCl2) is added to hydrochloric acid (HCl). The result is no visible reaction.
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sodium sulfide (Na2S) is added to cobalt(II) chloride (CoCl2). The result is a black precipitate.
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sodium bromide (NaBr) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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sodium chloride (NaCl) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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cobalt(II) chloride (CoCl2) is added to sodium chloride (NaCl). The result is no visible reaction.
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sodium carbonate (Na2CO3) is added to cobalt(II) chloride (CoCl2). The result is a pink precipitate.
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cobalt(II) chloride (CoCl2) is added to sodium carbonate (Na2CO3). The result is a pink precipitate.
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sodium iodide (NaI) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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sodium hydroxide (NaOH) is added to cobalt(II) chloride (CoCl2). The result is a red solution and a blue-green precipitate. This is an ancillary version.
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sodium hydroxide (NaOH) is added to cobalt(II) chloride (CoCl2). The result is a red solution and a blue-green precipitate.
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cobalt(II) chloride (CoCl2) is added to sodium hydroxide (NaOH). The result is a green precipitate. This is an ancillary version.
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cobalt(II) chloride (CoCl2) is added to sodium hydroxide (NaOH). The result is a green precipitate. This is an ancillary version.
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cobalt(II) chloride (CoCl2) is added to sodium hydroxide (NaOH). The result is a green precipitate. This is an ancillary version.
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cobalt(II) chloride (CoCl2) is added to sodium hydroxide (NaOH). The result is a green precipitate. This is an ancillary version.
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cobalt(II) chloride (CoCl2) is added to sodium hydroxide (NaOH). The result is a green precipitate. This is an ancillary version.
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cobalt(II) chloride (CoCl2) is added to sodium hydroxide (NaOH). The result is a green precipitate.
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sodium sulfate (Na2SO4) is added to cobalt(II) chloride (CoCl2). The result is no visible reaction.
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ammonia (NH3) is added to cobalt(II) chloride (CoCl2). The result is a blue-green precipitate. This is an ancillary version.
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ammonia (NH3) is added to cobalt(II) chloride (CoCl2). The result is a blue-green precipitate.
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cobalt(II) chloride (CoCl2) is added to ammonia (NH3). The result is a green precipitate.
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