CEMIN

Acid Plant Database September 2, 2026

Owner	CEMIN	-
Location	Domeyko Atacama Region Chile
Background	100% owned by Compania Explotadora de Minas (CEMIN)
Website	www.cemin.com
Plant	-
Coordinates*	28° 59' 2" S, 70° 53' 8" W
Type of Plant	Sulphur Burning
Gas Source	Elemental Sulphur - Bulk
Plant Capacity	300 MTPD
SA/DA	DA
Emissions	SO₂: 12 Nm³/h Stack Flow: 23,110 Nm³/h
Status	2019 - Shutdown
Year Built	2010
Technology	MECS (Basic Engineering Only)
Contractor	CEMIN
Remarks	Power generation An expansion to 450 MTPD was planned but was not completed
Pictures
General	-
References	-
News	August 21, 2025 - Marimaca Copper Corp. is pleased to announce it has recently executed a binding asset purchase option agreement to acquire a used sulfuric acid plant in Chile from CEMIN Holding Minero. Sulfuric acid is one of the key input costs for the Marimaca Oxide Deposit (“MOD”), and the ability to produce a significant amount of its own supply will reduce exposure to a volatile acid market. - Option agreement to acquire sulfuric acid plant for US$2.5m - Exclusivity period of 3-months to allow further detailed technical and engineering reviews including capital and operating cost estimates for the installation and operation of the sulfuric acid plant - Plant capacity of up to 150ktpa of concentrated sulfuric acid, representing approximately 30% to 40% of total acid consumption at the Marimaca Oxide Deposit depending on phase of developmento - Substantial opportunity to reduce volatility of key input cost (sulfuric acid) - Based on market research and quotations received by Marimaca – the estimated equipment cost of a new sulfuric acid plant of similar capacity is approximately US$35-40m, with total installation cost of US$50-US$60m - Relocation to Mejillones and start-up costs of used plant expected to be materially lower than cost of new equipment· - Indicative operating costs show potential for approximately 30% reduction in acid cost relative to current long-term forecast and normal historical spot and contract acid prices delivered to Mejillones - Simplifies acid storage strategy due to relative ease of storing physical elemental sulfur when compared to concentrated sulfuric acid - The Company has completed initial engagement with industrial operators in Mejillones with respect to installation of sulfuric acid plant - Significant mitigation of key financial risk for the Company - The MOD Definitive Feasibility Study, now largely complete and undergoing final review before publication, will not capture potential value upside from this acid strategy – a clear opportunity for optimization The MOD is forecast to be a mid-level acid consumer in the context of Chilean heap leach operations, and we continue to recognize acid cost as one of our most important drivers of profitability. We have numerous operational levers we can utilize to reduce acid consumption, if necessary, however, lowering the volatility associated with one of our key consumables was a logical step for the Company. “Based on current projections from Comision Chilena del Cobre (“Cochilco”), which provides industry forecasts for long term acid supply and demand in the Chilean market, the expectation is for acid prices to normalize at around US$95/tonne in Mejillones from 2028 onwards. Our analysis indicates, based on today’s elemental sulfur price (CFR Mejillones), a Company-owned acid plant could produce sulfuric acid for approximately US$70/tonne, excluding by-product credits from heat generation. This represents an approximate 30% reduction from the current long-term acid price forecasts from Cochilco. This discount is even more significant if you consider current spot prices, which are artificially elevated by H₂SO₄ seaborn freight rates and strong demand from the global fertilizer industry.” “In addition, while the elemental sulfur and global sulfuric acid markets exhibit reasonably strong price correlation, the underlying volatility of the final acid cost via a sulfur burner is reduced. This is due to stoichiometric relationship of reacting one tonne of elemental sulfur to produce approximately three tonnes of concentrated (98%) sulfuric acid.”

MTPD - Metric Tonne per Day STPD - Short Ton per Day
MTPA - Metric Tonne per Annum STPA - Short Ton per Annum
SA - Single Absorption
DA - Double Absorption

* Coordinates can be used to locate plant on Google Earth


Sulphuric Acid on the Web^TM	Technical Manual	DKL Engineering, Inc.