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Raw lithium carbonate can often be replaced with a lithium-containing frit if you can do the chemistry. And you can at insight-live.com.
Raw lithium carbonate has become incredibly expensive. That adds insult to injury since it is also a real pain to use. Unfortunately, alternative raw sources, like spodumene, have serious use issues also. Lithium frits are also expensive but enable the use of a lower Li2O percentage (because they are premelted) and they are less troublesome and safer to use. When the lithium percentage is low enough using a lithium-containing frit provides a real opportunity to improve the glaze and lower the cost.
This is an outline transcript of this video.
There are many reasons to use frits in glazes.
An example is the use of barium or lithium frits to avoid the use of the carbonate forms of these materials.
We will start using a popular Albany Slip glaze used for years.
It contains 11% lithium carbonate. If we click on that we can see that 59% gases off during the firing.
Let's search for Frit 493 in the reference materials.
It has 11% Li2O, but it supplies others also.
Click on Lithium carbonate, it has 40% Li2O.
I will duplicate this recipe. Then edit it, replace the lithium carbonate with Fusion Frit F-493.
I'll put 15 in the amount column (three times as much), and reduce the Albany to 66.
Save. Done.
Go into calculation mode and turn the tin.
I have oversupplied the KNaO by a lot, and there is too much SiO2.
I do not have a material in the recipe that contains these that I can reduce to compensate.
This is a problem, the host glaze has to be such that adjustments can be made to accommodate the frit.
Another problem is that I have brought in B2O3 that I do not want and I have not even supplied all of the Li2O.
11% is a lot of lithium carbonate in a glaze, you would never normally find that much.
Let's try another more suitable recipe.
I will close these two recipes.
I will open 1214W Lithium Boost. Duplicate it.
Before editing: Based on our experience I will need 4 times the frit as lithium carbonate.
This frit also supplies sodium, so I am likely not going to need the feldspar.
It supplies boron also. Click Frit 3134. It has alot more boron than Frit F-493, so we will need some of it.
Replace the lithium carbonate with 20 of Frit F-493. Save. Remove the feldspar. Done.
Compare: I have undersupplied CaO, oversupplied KNaO and B2O3.
Go into calculation mode. Set both recipes at Non-Unity. Scale the screen down.
The formulas look alot different. Trace amounts normally not seen are here, the numbers are much higher, but they still maintain their relationship with each other.
But this is better because the numbers will not jump around during unity recalculation as I supply from materials.
I am tempted to supply the CaO first from wollastonite, but it is better to deal with more complex boron and KNaO suppliers first.
I will highlight the Li2O oxides and reduce the frit F-493 until the Li2O numbers match (approx).
I want to reduce the Frit 3134 until the KNaO numbers match (it is quite a ways).
We have a problem: Now the B2O3 is too low. If I bring that up... so I will need to compromise.
The Al2O3 needs to come up but we already have a lot of clay in the recipe (25 parts out of 81) Cracking, crawling.
The problem is the frit: notice it has no alumina. I need another similar frit having some Al2O3.
Search 3124. It is the same but has alumina.
I will change 3134 to 2124. Save. Done.
It is not linking to the chemistry. Reenter the name as Ferro Frit 3124.
Enter B2 and increase the frit to match the B2O3. This frit has less B2O3 so I have to move it more.
Bump up Frit 493 0.5%.
Now I will do the CaO from Wollastonite.
Compare the B2. Reduce the frit a little, add a little more Al2O3 from the Kaolin, then match the SiO2 from silica.
Retotal to 100.
Set it back to Unity formulas.
Notice the LOI is way down, that will reduce the tendency to blister.
I could have matched the CaO a little better. This is close.
I am being content with KNaO. B2O3 is a little off. I have one less material in the recipe.
There is more frit so it will be more expensive.
I will turn calculation mode off by clicking the search button.
Here is my recipe to print and try.
Materials |
Lithium Carbonate
A powerful melter very valuable in ceramic glazes. It is 40% Li2O and has an LOI of 60% (lost as CO2 on firing). This material in now incredibly expensive. |
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This is 85% Alberta Slip, 11% lithium and 4% tin fired at cone 6 in oxidation. Like the original Albany version, it has a very low thermal expansion (because of the high lithium content) and likes to shiver on many clay bodies.
You will see examples of replacing unavailable materials (especially frits), fixing various issues (e.g. running, crazing, settling), making them melt more, adjusting matteness, etc. Insight-Live has an extensive help system (the round blue icon on the left) that also deals with fixing real-world problems and understanding glazes and clay bodies.
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