Metallurgical lime, agglomeration cement and leaching process reagents
When you go looking for how much lime a gold mine consumes, it is not there: nobody publishes the ratio of kilos per tonne. But two technical reports publish the dollars, and that is enough. Veladero, which does not agglomerate, spends fifteen cents of a dollar per tonne across lime, cyanide and zinc. Gualcamayo, which does agglomerate, pays USD 2.00 per tonne more simply to move from oxide to sulphide ore, and its own report says that difference is lime, cement and cyanide. Together they say what neither says alone: what decides the size of this market is not how much lime is used, it is which ore is processed — and San Juan is about to change ore. The Vicuña technical report, of March 2026, confirms it and adds a physical condition that decides who can sell: lime is the pH modifier of its three stages, and its lime silos are designed for seven days of stock against thirty for every other reagent. Seven days of autonomy is not an engineering detail: it is a requirement of proximity.
This is the only San Juan niche whose market already bills every day and does not depend on any project starting: the reagent is operating expenditure, it is consumed while the mine is processing and it has no window.See the clocks that are running, one by one
On this page
What the market is made of
The split of this niche is decided by what can be made here and what cannot. Cyanide is made by a handful of plants worldwide under licence and an international management code, and it weighs twice what lime does per tonne processed. Lime and cement are indeed made in San Juan: the province has 2.1 million tonnes of installed lime capacity and sold 1.1 in 2025.
Mining-grade sodium cyanide and the zinc used in precipitation: a handful of plants worldwide, licensing and an international management code, with the miner auditing its supplier. At Veladero they weigh USD 0.08 and USD 0.03 per tonne processed against lime's USD 0.04. ~USD 4.0 M/yr, 63 % of the midpoint. estim
Metallurgical-grade lime and agglomeration cement —which the province already produces, with idle capacity— plus the storage, conditioning and last mile of every reagent, which is a service rather than a product. ~USD 2.3 M/yr, 37 % of the midpoint. estim
It is not building a lime plant: the province already has capacity to spare. It is the storage, conditioning and last mile of the reagent —a service rather than a product— and, on the lime side, doing the qualification work nobody did: testing, publishing the specification and getting vetted mine by mine. ~USD 0.6 M/yr at first, multiplying when the copper concentrator comes online. thesis
Who really pays?
Three payers, and the third does not buy yet but is the one that decides whether the kiln is worth building:
Veladero pays this spend every month: its 2018 technical report gives USD 0.04 of lime per tonne processed over 28 to 29.5 million tonnes a year between 2014 and 2017, and describes the lime added to the crushed ore with no agglomeration stage verif. At Gualcamayo, the 2021 technical report attributes the extra USD 2 per tonne it costs to process sulphide ore to agglomeration lime and cement, together with more cyanide verif; today its output centres on re-leaching the heaps already built prob. Our reading: Gualcamayo spends more lime and cement per tonne than Veladero, over a much smaller tonnage thesis.
This is the door that needs no kiln. It includes cyanide, which is half the spend and which nobody is going to manufacture here, but which does have to be received, stored and hauled up to the mine to international management standard. A service rather than a product: it enters with far less capital and qualifies faster.
They do not buy yet. Vicuña's state act is already published and sets 31 December 2028 as the deadline to meet its minimum investment verif, and its technical report places the first year of production in 2030 verif. Gualcamayo's operator announces Carbonatos Profundos production for 2029, although its own schedule puts start-up in 2030 prob. Our reading: they are the reason this niche exists thesis.
Which projects move this demand
Engineering, construction, operation and maintenance of new leach pads (phases 8 and 9) at Veladero Mine, to sustain gold production and exports…
see the project →Reactivation and deepening of the Gualcamayo gold and silver mine (San Juan): the 'Deep Carbonates (DCP)' project extends the mine life toward the sulfide orebody at depth…
see the project →The largest mining project in Argentine history by announced investment, and, according to the operator…
see the project →When the window opens
Reagent spend moves with two things and no more: how many tonnes are processed and which ore they are. These four numbers say it before anyone else.
See the evidence
See the evidence
See the evidence
The risk in this niche runs the opposite way to how it looks: financing a new lime plant is the bad deal. The province has 2.1 million tonnes of installed capacity and sold 1.1 in 2025, with the main lime plant running at around half prob sector press.
See the evidence
The entire 2030 argument rests on lime being the reagent of greatest mass in copper flotation, which is known process physics, but no open source publishes how much.
See the evidence
It weighs twice what lime does per tonne processed verif Veladero technical report, Table 21-4 and is made by a handful of plants worldwide under licence and an international management code.
See the evidence
An off-specification lime batch moves the circuit's pH and with it the gold recovery the operation lives on. That is why the miner tests, qualifies and changes slowly. The qualification cycle is measured in months and price does not shorten it.
See the remaining 3 risks
The 28.8 million tonnes come from Table 21-3 of a 2018 report. The 2014-2017 series moved less than 6 %, and phases 8 and 9 —with a published act of State and USD 436 M— extend the leach valley, so the order of magnitude holds.
See the evidence
Minas Argentinas has already flagged the lime business inside its second Gualcamayo project. If it does it, it not only stops buying: it is left with installed capacity to sell to the rest of the province, and it does so from inside a mining operation, with the limestone and the permit already sorted.
This is the gap that remains, and it is one of evidence, not of capacity. We looked for a product data sheet at the province's scale lime plant and there is only a safety data sheet.
See the evidence
The opportunity in depth
The opportunity in depth
The capacity is already installed and unused. The province has 2.1 million tonnes of lime capacity and sold 1.1 in 2025; the large-scale lime plant runs at around half of what it can, and the province places more than half of what it sells through exports, mostly to Chile. Putting up a new kiln competes against a kiln already paid for.
What does not exist is the proof. No San Juan lime plant publishes reactivity, particle size or available calcium oxide — the large-scale one offers the safety data sheet and no product data sheet — and none names a mining customer. A mine buyer cannot even begin to compare with what is published.
And there is a door that needs neither kiln nor quarry: the storage, conditioning and last mile of imported reagent, to international standard for cyanide. It is a service rather than a product, and it enters with far less capital.
The layer that decides is physical and it is written in a document. Vicuña's lime silos are designed for seven days of stock, against thirty for every other reagent. Seven days of autonomy forces continuous, nearby supply: it is the condition a supplier a thousand kilometres away cannot meet, and the one a San Juan supplier already meets without investing anything.
When you get paid, and what blocks it
already in
split
The province's industrial lime plant, and the one that decides the premise of the whole niche. It has four 300-tonne-per-day Maerz PFR kilns «in operation» —the fourth was lit in June 2026—, a fifth in engineering and two 150 t/day vertical kilns of installed capacity, plus a crushing, screening and bagging plant.
See the evidence
This is the part of the niche that is not contested, and it is worth saying up front: mining-grade sodium cyanide is made by a handful of plants worldwide, it is transported and stored under the International Cyanide Management Code, and the miner audits its supplier.
See the evidence
Worth watching because it is not a supplier wanting to sell: it is an operator wanting to integrate backwards. It flagged the lime business inside its second Gualcamayo project, on the high-purity limestone of its own deposit.
See the evidence
Agglomeration cement travels the same network as construction cement and its owners are the usual ones. It is the part of the niche where an entrant has least to do — except storage and the last mile to the mine, which is a service rather than a product, and there proximity counts again.
The jobs it createsWhat this niche can leave behind is not a new company: it is putting to work an industry the province already has and that today runs at half throttle.the detail on jobs and trades
calculate it
The number is our own estimate. The calculation, step by step, is below.
The full calculation, step by step
Concentration Split in two, and the division is what defines the strategy. Cyanide is highly concentrated: a handful of plants worldwide, licensing, an international management code and auditing by the miner — there is no door there for an entrant, and it weighs twice what lime does in the spend per tonne. Lime and cement are far less concentrated, and in the province there is a surplus of them: San Juan has 2.1 million tonnes of installed lime capacity and sold 1.1 in 2025, with the main lime plant running at around half of what it can. That is why the barrier is neither the quarry nor the kiln: it is qualification —reactivity and particle size tested by each operation— and, one step before that, publishing a specification that nobody publishes today.
The rule that moves it
Here the rule does not create the demand —the reagent is consumed either way— but it decides something finer and more useful: whether lime made in San Juan counts as local content for the miner that uses it, which is what can tip the decision to buy from a new lime plant rather than the usual supplier:
See the underlying reading
The underlying policy that opens up this demand. It is the same inference declared by the rules and the program pillars pushing in this direction.
cheaper to respond: investing takes time, held-back supply shows up at onceSee the full legal grounds
Where the number comes from
USD 4.3-8.3 M/yr today, midpoint ~USD 6.3 M. ⛔ And what governs is not that number but what comes next: in 2030 the province would process more than twice as much, and that part is not here
See the calculation, the variables and how it was validated
Two blocks, one firm and one deliberately wide. The first rests on two published tables; the second on a band the report does not break out.
The number rests on a few variables. The formula shows how it moves when each one changes; and each variable carries its freshness seal — how often it is worth revisiting. estim
San Juan does not import its lime: it makes it, and it has a surplus. The province has a lime plant with installed industrial capacity running at half throttle, so this niche's gap is not in the kiln.What there is, opened with our own eyes on 14 September 2026:
| what | who publishes it |
|---|---|
| Four 300-tonne-per-day Maerz PFR kilns «in operation», a fifth in engineering, two 150 t/day vertical kilns of installed capacity, and a crushing, screening and bagging plant | Caleras San Juan S.A., on its own site |
| Its lime is fit for mining: *«depressant and alkalising agent in the flotation of Cu, Zn, Pb and Ni ores»*, *«pH regulator in the extraction of Au and Ag in cyanide leaching»* | the same |
| ISO 9001, 14001 and 45001 since 2022, recertified in August 2025 | the same |
| The fourth kiln was lit in June 2026 and with it capacity reaches 600,000 tonnes a year prob Cámara Minera de San Juan | the Cámara Minera de San Juan |
| The province has 2.1 million tonnes of capacity and sold 1.1 in 2025, and the company runs *«at a little over 50 % of capacity»* | its general manager, in a February 2026 interview |
| document | what it publishes | where |
|---|---|---|
| Veladero technical report (Barrick, March 2018, 183 pages) | Cyanide USD 0.08 · Lime USD 0.04 · Zinc USD 0.03 per tonne processed, on separate lines | Table 21-4 |
| the same | Tonnes processed: 29.5 · 28.4 · 28.0 · 28.8 million between 2014 and 2017 | Table 21-3 |
| Gualcamayo technical report (Mineros, September 2021, 228 pages) | Variable processing: USD 6.14/t for oxide ore and USD 8.14/t for sulphide verif Gualcamayo technical report, Table 21-3 | Table 21-3 |
| the same | Verbatim: the USD 2.00/t difference is *«increased lime and cement costs for agglomeration, as well as increased cyanide consumption»* | page 17-3 |
| Vicuña technical report (March 2026, 418 pages, downloaded and read in full) | Lime is the pH modifier of stages 1 and 3, and one of the eight reagents of stage 2. And the lime silos are designed for seven days, against thirty days of stock for every other reagent | § 17.7.3 |
How to cite this figure: Despegue (2026). Metallurgical lime, agglomeration cement and leaching process reagents · San Juan. despegueargentina.com/en/san-juan/cal-metalurgica-reactivos-lixiviacion · terms of use
Neighbouring markets3 markets in the same group, from USD 25 to USD 60 M a year
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