Why Los Pelambres’ desalination plant is becoming Antofagasta’s quiet workhorse

Far from the spotlight of copper prices, Antofagasta’s Los Pelambres desalination plant is quietly changing how the miner secures water for one of its key Chilean operations - with big implications for reliability, sustainability, and long-term costs.

Reviewed: ad hoc news Software & Services desk. Edited and checked on 2026-06-18, 20:27. Details in the imprint.

With the Los Pelambres desalination plant, Antofagasta plc has built an industrial service that feels more like life insurance than infrastructure for its flagship Chilean mine. The plant sits on the Pacific coast, turning seawater into a steady flow that keeps crushers, conveyors, and communities supplied even when the Andes stay dry.

What the plant delivers

The Los Pelambres desalination plant was designed as part of the Phase 1 expansion of the mine, adding a coastal water source that can eventually replace most freshwater withdrawals from the Choapa valley. According to Antofagasta, the plant has an initial capacity of 400 liters per second, with space to double that volume in a second stage. The company highlighted the plant as a key feature of the expansion in a 2022 update.

In practical terms, that means thousands of cubic meters of seawater are pulled in daily, filtered, pushed through high-pressure membranes, and then pumped uphill over more than 100 kilometers toward the mine site. For engineers, this is a complex service chain; for mine managers, it feels like turning the ocean into a predictable utility.

How it changes Los Pelambres

Before the desalination plant, Los Pelambres relied heavily on local surface water and groundwater, a growing risk in central Chile’s long drought. By shifting toward seawater, Antofagasta aims to secure production even in dry years and to ease pressure on agriculture in the valley below. The group’s water strategy explicitly points to seawater and desalination as the core of its long-term approach.

The new infrastructure does more than tick ESG boxes. It underpins the mine’s expansion, raising throughput while keeping regulators and local communities onside. When a conveyor stops today, managers worry about mechanical issues, not whether the river has dropped overnight.

Energy use and operating costs

Desalination is power-hungry, and Los Pelambres is no exception. The process and the long-distance pumping require continuous electricity, which Antofagasta is increasingly sourcing from renewables under long-term contracts in Chile. The company has reported that all its mining operations now use 100 percent renewable energy.

This has a double effect. It limits the carbon footprint of each cubic meter of desalinated water and brings some stability to operating costs. Still, the plant is a reminder that drought protection is not free - extra energy and maintenance are baked into every tonne of copper shipped.

Where the concept could go next

Los Pelambres is not the only Antofagasta operation looking toward seawater, but it is the most advanced. The plant’s modular design allows for additional capacity if later stages of the mine’s development require more water security. That gives the group a flexible tool to match future production plans.

For investors who think in decades, the desalination plant shows how the company is trying to future-proof a core asset in a water-stressed country. For local communities along the valley, it can mean less competition for rivers and aquifers that are already under strain.

Company context and stock reference

Los Pelambres sits at the heart of Antofagasta plc’s portfolio, and the desalination plant is a quiet but central enabler of the mine’s expansion and long-term operating license. Shares of Antofagasta plc (GB0000456144) trade on the London Stock Exchange in pounds sterling.

Key facts on Los Pelambres desalination

• Product: Los Pelambres desalination plant
• Manufacturer: Antofagasta plc
• Category: Software/Service/Subscription - industrial water service
• Launch: Phase 1 plant commissioned around 2022 as part of the Los Pelambres expansion
• RRP / Price: Part of the Los Pelambres expansion capex program, reported at approximately US$2 billion for the full expansion package
• Availability: Internal industrial use at the Los Pelambres copper mine in Chile
• Target group: Internal operations management and, indirectly, local communities and regulators relying on lower freshwater extraction
• Highlight / USP: Coastal desalination and long-distance pumping system that secures mine water supply while reducing pressure on local river basins

This article was AI-assisted and editorially reviewed. Product information without guarantee; prices and availability may change at short notice. No investment advice, no buy or sell recommendation. Stock-market transactions involve risks up to total loss.