Soda Ash and Boric Acid Come Out of the Same Lake

On 14 September 2026, a boron developer called 5E Advanced Materials signed an agreement to buy the production assets of Searles Valley Minerals out of bankruptcy. The consideration was about $3.4 million in cash, 8.3 million shares of stock and a promissory note of roughly $6.2 million. For that, the buyer gets processing plants, a brine field, an on-site cogeneration unit, a short-line railroad, and the right to make refined borates, boric acid, sodium sulfate and salt from a dry lake in the Mojave Desert that has been worked continuously since Ulysses S. Grant was in office.

Most coverage filed this under mining finance, or under the story of a company town in trouble. Both are true. But there is a third story inside it that matters to anyone who writes purchase orders, and almost nobody wrote it down: this single asset sat underneath two commodities that industrial buyers treat as completely unrelated. Soda ash goes in one budget line, usually next to glass, detergent or water treatment. Boric acid goes in another, usually next to ceramics, glass fibre or metal finishing. Different suppliers quote them. Different markets price them. At Searles Lake they come out of the same pumped brine, in the same plants, as products of the same evaporation.

This article is about the chemistry of why that is true, what the public record actually says about how concentrated these two supply chains are, and what a buyer should check on their own specification as a result. It is a market-structure piece, not a recommendation to buy or sell anything on a schedule, and it takes no view on the policy arguments around the closure. Where any individual distributor sources its material is a commercial matter, and this article makes no claim about ours.

What happened, in order

The end came slowly and then all at once. The useful thing about the sequence is that each step has a date and a document behind it, so you can see which pressures were structural and which were terminal.

Note the gap between February and September. The soda ash plant did not stop because the company went bankrupt; the company went bankrupt some months after the soda ash plant stopped. That ordering is the whole economic argument, and it points at production cost rather than at demand.

Why one bankruptcy moves two different line items

Here is the sentence that does the work, and it is not ours. It is the US Geological Survey, in the 2026 Mineral Commodity Summaries, describing the American soda ash industry:

Coproducts, not competitors. At Searles Lake the raw material is not an ore body that yields one mineral; it is a brine — a saturated solution pumped from wells that run from near the surface down past 330 feet — carrying sodium, potassium, carbonate, bicarbonate, sulfate, chloride and borate all at once. You cannot pump the carbonate without also pumping the borate. They arrive together, in the same pipe, and the plant’s job is to take them apart.

That is why a single corporate failure propagates into two unrelated-looking markets. It is not a supplier relationship or a shared logistics route, the kind of coupling a procurement team can design around by dual-sourcing. It is the same molecule stream. The commercial separation between “the soda ash market” and “the borate market” is real at the point of sale and fictional at the point of extraction.

So a buyer who holds two suppliers for soda ash and two suppliers for boric acid, and calls that four points of diversification, may have fewer than four. And as the later sections show, the concentration does not improve much if you decide to import instead.

What is actually dissolved in Searles Lake

The deposit is an evaporite: what is left when a lake dries. Searles Lake was the next-to-last basin in a chain fed by the Owens River during the Pleistocene, and the stratigraphy records that at times it held brackish water as deep as about 200 metres. Over roughly the last 150,000 years it filled and evaporated through about thirty major cycles, tracking the advance and retreat of glaciers in the Sierra Nevada. Each cycle laid down salt, then mud, then salt again.

That repetition is the point. A single evaporation sorts dissolved salts by solubility, precipitating the least soluble first. Thirty of them, stacked, built something closer to a fractionating column made of geology — interbedded salt bodies separated by muds, with interstitial brine held between them, and different layers enriched in different chemistries. More than 28 mineral species have been recorded there, including hanksite, halite, borax, trona, ulexite and gaylussite. Reserves have been described in the billions of tonnes.

Historically the operation ran three plants — Argus, Trona and Westend — using three different physical separations on the same brine: carbonation, refrigeration and solvent extraction, all forms of fractional crystallisation. Each exploits a different way of making one species drop out of solution while the others stay in. Carbonating the brine with carbon dioxide converts carbonate to bicarbonate, which is far less soluble and crystallises out; calcine it and you have soda ash. Chilling the brine drops sodium sulfate. Solvent extraction pulls borate out selectively. Same feed, three exits.

Why energy decided who survived

Every one of those separations is a phase change you have to pay for. You are either driving water off, or driving temperature down, or running a solvent circuit — and at Searles Lake there was an on-site cogeneration plant precisely because the process is an energy conversion wearing a chemical hat. The company has put energy at close to half of production cost for soda ash and boric acid. That figure is the hinge of the whole story.

Compare the competing route. Wyoming’s Green River Basin holds an estimated 90% of the world’s known trona, a sodium carbonate-bicarbonate mineral you can simply mine as rock and calcine. You still pay for heat, but you do not pay to concentrate a dilute solution first. Natural trona beats brine carbonation on energy, and natural soda ash of any kind beats the synthetic Solvay route, which is why the USGS notes that producers in China, Turkey and the United States “benefited from relatively low production costs” from natural sources while synthetic production “typically consumes more energy and costs more”.

Then the price moved. US soda ash, average unit value of sales from natural sources, free on board mine or plant:

From the 2023 peak to 2025 that is a fall of about 29%. The USGS attributes the global decline to oversupply and weak demand from key industries, “largely driven by China’s expansion of natural soda ash production in Inner Mongolia, which added about 5 million tons per year of capacity in mid-2023”. China alone produced an estimated 38 million tonnes in 2025, most of it synthetic; China, the United States and Turkey together made up roughly 80% of world output.

Put the two facts next to each other and the outcome is arithmetic rather than opinion. If your process is the most energy-intensive way to make the product, and the product’s price falls by nearly a third, you are the first plant to stop. A commodity whose cost is half energy does not have a price; it has an energy price with extra steps.

What US soda ash supply looks like now

The scale here surprises people who only meet soda ash as a bag of pool chemical. US production in 2025 was an estimated 12 million tonnes, worth about $1.8 billion, up 3% on 2024. Nameplate capacity across the five producing companies was 13.9 million tonnes per year. More than half of US production was exported. Imports were trivial by comparison — 35 thousand tonnes — and the United States is a net exporter.

Where it goes, on 2025 quarterly reports:

So the honest answer on soda ash availability is reassuring, and it is worth saying plainly rather than dramatising the closure: the United States makes far more soda ash than it uses, exports the surplus, and the lost California plant was a small share of a 12-million-tonne total. Nobody rational should expect a soda ash shortage from this.

It is also worth knowing where the imported alternative comes from, because the answer is narrow: US soda ash imports over 2021–24 were Turkey 89%, Canada 3%, Mexico 3%, other 5%. The tariff line for disodium carbonate sits at 1.2% ad valorem.

The boron half, which is where the buyer actually bought the lake

5E Advanced Materials did not pay for soda ash. It paid for boron, and it said so: the press release notes that boron was added to the US critical minerals list in 2025, and that on closing the company “would be the only American-owned producer of borates in the United States”. That last phrase is the buyer’s characterisation of its own position rather than an independent finding, so treat it as such — but the designation behind it is a matter of public record. The final 2025 US critical minerals list was published in the Federal Register on 7 November 2025, and the USGS confirms that boron was among the minerals added.

The US borate picture is tighter than the soda ash one in every direction:

Read the first two rows together. Every pound of borate mined in the United States comes from one corner of one state, and two of the three producers get it out of brine rather than ore. The mineralogy explains the split: the leading producer works borate ores by open pit — kernite, tincal and ulexite — where kernite goes to boric acid, tincal to sodium borate, and ulexite into specialty glasses and ceramics. The other two pull dissolved borate from solution. Searles Lake is one of those two. The buyer’s own Fort Cady project, near Newberry Springs, is a solution-mining boron operation in the same desert.

Which means the transaction is not only a rescue; it is a consolidation of the Mojave brine-borate capacity under one owner.

And now put the two import lines side by side, because this is the part that undoes the obvious hedge. US soda ash imports: Turkey 89%. US borate imports, all forms: Turkey 90%. A buyer who responds to domestic concentration by importing has not diversified away from a common point of failure; they have swapped a shared deposit for a shared country. The two commodities were coupled at Searles Lake by geology, and they are coupled on the import side by trade structure. There is no easy third leg.

What to check on your own specification

None of the above is a reason to change what you buy this quarter. It is a reason to know what you are actually buying, because the failure mode in a consolidating market is not usually a shortage — it is a substitution that arrives quietly and does not match your process.

Four things worth confirming on your own paperwork:

1. Know which grade the specification actually requires, not which one you have always ordered. Soda ash for glass, detergent or pH adjustment is a technical-grade sodium carbonate and the specification is usually assay, moisture and particle size. Boric acid divides more sharply: technical grade serves industrial duty, while reagent-level purity exists because trace metals interfere with analytical and synthesis work. Paying for reagent purity in a process that does not care about trace metals is a cost you can remove; discovering you needed it after a substitution is a cost you cannot.

2. Confirm the assay basis. Borate products are priced and sold on their boric oxide (B₂O₃) content, which varies by ore and by compound and with the presence of sodium or calcium. Two quotes for “boric acid” can differ because they are quoting different things. Ask what the assay is stated against.

3. Do not swap concentration or form to chase availability. Powder, granular and solution forms behave differently in dissolution rate, dust and dosing, and a change of physical form in a metering system is a process change even when the chemistry is identical.

4. Ask for the lot-specific Certificate of Analysis before you qualify a new source, not after. A CoA on the lot you are about to run is the cheapest way to catch a substitution.

Common questions

Did the Searles Lake operation shut down permanently?

Not entirely. Soda ash operations were shut down in February 2026 and the boric acid LLX plant was mothballed back in 2024. The Chapter 11 sale signed on 14 September 2026 transfers the production facilities, brine resources, cogeneration, the Trona Railway and the production of refined borates, boric acid, sodium sulfate and salt to 5E Advanced Materials, with closing expected in early October 2026 subject to court and regulatory approval. The stated strategic focus of the buyer is boron, so the borate assets and the soda ash assets should not be assumed to share a future.

Why would a soda ash bankruptcy affect boric acid at all?

Because at Searles Lake they are coproducts of the same brine. The USGS states directly that in California, borax, salt and sodium sulfate were produced as coproducts of sodium carbonate production. The dissolved carbonate and the dissolved borate are pumped from the same wells and separated at the plant, so the economics that stop one can stop the other.

Should I expect a soda ash shortage?

There is no evidence for one in the public data. US production in 2025 was an estimated 12 million tonnes against roughly 4.7 million tonnes of apparent consumption, with more than half of production exported and the country a net exporter. The meaningful change is concentration: domestic production is now effectively confined to the Wyoming trona basin.

Where does US boric acid come from?

Three companies in southern California produced borates in 2025, two of them from brine by solution mining and one working borate ores by open pit. Domestic production and consumption figures are withheld by the USGS to avoid disclosing proprietary data. Imports are modest against exports, and over 2021–24 about 90% of US borate imports in all forms came from Turkey.

Is boron a critical mineral in the United States?

Yes. The final 2025 US List of Critical Minerals was published in the Federal Register on 7 November 2025 at 90 FR 50494, and boron was among the minerals added alongside metallurgical coal, phosphate and uranium.

Does any of this change which grade I should order?

It should not change the grade; it should make you verify it. Confirm what your process actually requires on assay, purity and physical form, confirm the basis the assay is quoted against, and request the lot-specific Certificate of Analysis when qualifying a new source rather than after the first delivery.

The three we stock

Soda Ash — Sodium Carbonate, Technical

The industrial alkali: pH adjustment, glass and ceramic batch, detergent builder, process water.

Boric Acid Technical Grade

Industrial working grade for ceramic and glass work, metal finishing and general process duty.

Boric Acid Powder 99% ACS Grade

Reagent purity, for analytical and synthesis work where trace metals interfere.