Spodumene Substitute Analysis

[Min]

Laguna's Spodumene Substitute Analysis below. Compared to Insight Glaze Calc Materials Data the Li2O is down nearly a full percent. (Slight decrease in Al2O3 and SiO2 although those are probably not significant in most glaze recipes)

I asked Pottery Supply House in Ontario if their Spodumene Blend is the same product and they confirmed it is.

I would suggest the Li2O difference could very well make a difference to glaze fit and/or colour response in some glazes. So not only is the price of spodumene through the roof we now probably need to use a bit more of it compared to the old chemistry.

[Hulk]

I'd noted Spodumene, Petalite and Lithium Carbonate pricing 1-DEC-22

At that time, northern California supplier (that I frequent) had a better price than other vendors I've used.

Same NorCal vendor, since then, Petalite has gone up 25%, Spodumene (substitute) is up a bit over one third!
The spod is well over twice the cost per pound, but it doesn't have 2x the lithium.
Their spodumene sub is 6.8% lithium.

I'd already (somewhat arbitrarily) chosen petalite for a lithium source; the recipe in question has just a trace of lithium, so I believe petalite is appropriate...
The lithium unity, percent by weight, and mole percent are 0.133, .88%, and 1.86%, respectively.

Any road, if the percent lithium changed, for sure I'd revisit the formula/recipe, for lithium is powerful stuff!

[Mark C.]

This news makes me lucky that I stocked up on these items long ago-I'm down to 20#s of Spodumene but I only use it in one glaze. Some materials have gone thru the roof

 

[Dick White]

This discussion of a spod substitute blend is interesting in another way. I personally and the studios I work with have enough spod on hand to meet our needs for quite awhile, if only because we don't use much of it. I even have some of the old Foote, as well as the newer Gwalia. What strikes me now is how reminiscent this is of the time the Gerstley Borate mine closed. It didn't take long for a number of substitute blends to move into that vacant space - Laguna Borate, Gillespie Borate, CadyCal, Mexican blends, etc. Is that the future of spod - a dozen different blended substitutes to figure out? And what's with Gerstley? Laguna pulled 3,000 tons of the unprocessed ore out of the mine yard and brought it back to market. Now it costs as much as frit. Does that mean  Laguna is running out and can charge a premium for what's left?

[Mark C.]

I can add to that laguna story  Dick on Grestly-they bought the mine when it was running out (actually is was just more contaminated with other stuff) I drove by that mine for 25 years twice a year on a way to my AZ art shows. Anyway I bought a ton of it at the time just before it went away the 1st time. Then after they bought the mine it came back on the market for years at a resaonable cost.. Now years later its almost gone again and the price reflects that change now.

I have mentioned for all my time on this forum to buy in bulk when you can and this is just another nail in that suggestion.

[Orbit]

I just bought 25 lb of petalite for what is now a really good deal from the Dakota Potter’s Supply and had it couriered to me in Minneapolis, and have 5 lb of spodumene, and am hoping that will get me through a number of years, mostly subbing petalite for spodumene. Unfortunately I use a lot of glazes that need some form of lithium, although fortunately I have the skills to alter the recipes to make the subs work. What I’m most concerned about is all my raku glazes, most of which require lithium carb, and are otherwise mostly made of frit with either neph sye or Gillespie borate at about 10%. I don’t know how easy or possible it will be to adjust the silica and alumina levels with those recipes to allow me to use petalite instead of lithium carb, which I only have about a lb left. And I’m not even sure petalite forms a eutectic with those ingredients at the about cone 06 I do my raku, so that it will melt into the glazes. Any insight would be appreciated. The other non raku glazes I’m not worried about, it is a lot of turquoises, teals, shinos which need the lithium for color, and a few crystalline glazes which probably I can just remove the lithium entirely from the recipe and fire them a little hotter.

Edited July 5, 2023 by Orbit

[Min]

Hi and welcome to the forum!

Hopefully the cost of lithium products will be coming down sooner rather than later. The Sayona mine in Quebec Canada is set to reopen fairly soon. Also with the extraction method that uses ponds to evaporate seawater for it's lithia content there is also talk of using water from Turkey (I think) that has been found that has a higher concentration of lithia than is the norm so that should help too. When the Canadian spod no longer was available 20 odd years ago there was a lot of outcry that shino glazes were not working as well with the Australian spod. I think that came down to the Canadian spod had a tiny bit of iron in it.

42 minutes ago, Orbit said:

I don’t know how easy or possible it will be to adjust the silica and alumina levels with those recipes to allow me to use petalite instead of lithium carb, which I only have about a lb left. And I’m not even sure petalite forms a eutectic with those ingredients at the about cone 06 I do my raku, so that it will melt into the glazes.

The combo of sodium plus potassium aids in the melting of the lithia, I would be looking at those also. 

With  the petalite version recipe how much is the silica too high? (since gram for gram it is lower in lithia)

[Orbit]

The raku recipes are the more difficult ones, because they usually call for just lithium carbonate, and I want to put in petalite instead, which has over 70% silica plus alumina and I am not sure how easy it will be to alter the amounts of frits to adjust for that. It is a good point to be looking at the potassium and sodium amounts as well in aiding the melting of the lithium, the raku glazes in general are extremely high in sodium. I’m somewhat at a loss about subbing petalite for lith carb in raku glazes, except for the ones that have a somewhat decent amount of Nepheline syenite in them because it will be easier to adjust that for subbing petalite. I just came across while doing some googling of extracting lithium carb from petalite and I’m trying to determine if it is something I can do at home with my chemistry background from my former life as a scientist (I was very good at making pretty crystals in organic chemistry lab!).

[Hulk]

Glaze calc software may be helpful*!

There are Forum regulars using Insight, and also Hyperglaze.
I'm using Hesselberth's GlazeMaster.
Glazy's interface has some interesting features.

Any road, in GlazeMaster I can tweak the ingredient percentages, then note the oxide percentages/ratios in Unity, Weight, and Mole, and compare against several "limit" sets.
To start, I added twelve percent Petalite, then adjusted the other ingredients to get close to the original Unity amounts of the other oxides...

Just .133 (Unity) of lithium cleared up my liner glaze crazing problem; to get that .133  takes 18.9% Petalite!
I also reduced the Sodium and Potassium, upped Magnesium Oxide (talc), and added some Zircopax...

My guess, it would be difficult to balance a glaze recipe that requires a much higher amount of lithium (over a percent, by weight), using Petalite as a source.
Looks like I could bump the lithium up quite a bit in my liner glaze, as the current recipe has almost 25% Silica and 19% EPK, however, I don't need to.

Any road II, Petalite works for me.
At the time, the cost per unit Lithium was less than using Spodumene as a source, and I very much wanted to avoid any soapy bubbling problems.
Also at the time, I'd read up on Lithium toxicity, solubility, et cetera.

A very small amount of Lithium can make a big difference, my experience.
 

*..of course, afore there were software options, glaze calc was done longhand; it's certainly doable!
I gave it a try when trying to understand Unity, then, having been through a few calcs, was happy to then leave the maths details to the software.

Edited July 6, 2023 by Hulk
what is a higher amount?

[Orbit]

I use Insight for my glaze calculation, I know how to do it. That’s why I said that it is really hard to substitute petalite for lithium carb in raku glazes. It is possible for cone 6 or higher glazes, within reason. 

[Orbit]

On 4/1/2023 at 10:45 AM, Min said:

Laguna's Spodumene Substitute Analysis below. Compared to Insight Glaze Calc Materials Data the Li2O is down nearly a full percent. (Slight decrease in Al2O3 and SiO2 although those are probably not significant in most glaze recipes)

I asked Pottery Supply House in Ontario if their Spodumene Blend is the same product and they confirmed it is.

I would suggest the Li2O difference could very well make a difference to glaze fit and/or colour response in some glazes. So not only is the price of spodumene through the roof we now probably need to use a bit more of it compared to the old chemistry.

I’ve been looking at the Barnard sub from Laguna as well, now that I know they have one, and was astonished at how off their amounts of RIO and MnO are in the substitute compared to the original Barnard slip. I’m a little astonished that Laguna isn’t doing a better job with its substitutes, same with their Newman’s Red sub. 

[PeterH]

On 7/6/2023 at 4:41 PM, Orbit said:

I just came across while doing some googling of extracting lithium carb from petalite and I’m trying to determine if it is something I can do at home with my chemistry background from my former life as a scientist

Interesting idea, do you have any specific approaches in mind?

Lithium extraction from hard rock lithium ores (spodumene, lepidolite, zinnwaldite, petalite): Technology, resources, environment and cost
http://en.cgsjournals.com/article/doi/10.31035/cg2022088

Lithium extraction from mechanically activated of petalite-Na2SO4 mixtures after isothermal heating
https://www.sciencedirect.com/science/article/abs/pii/S089268752030114X
... full paper behind a firewall, but the relative solubilities of Na2SO4 & Li2SO4 suggests that Li2CO3 would precipitate out  first.