Sandman Gold Recovery: Crushing, Heap Leach & ADR Process

Source: Borealis Mining Company Limited (formerly, 1329300 B.C. Ltd.) (2026)
Website: https://borealismining.com/the-sandman-project/

Critical Data

Overview

Borealis Mining Company Limited is advancing the Sandman Gold Property in Nevada, USA, a project that leverages conventional yet highly efficient recovery methods for gold extraction. The Preliminary Economic Assessment (PEA), effective January 2026, outlines a robust processing flowsheet centered on crushing, heap leaching, and adsorption-desorption-regeneration (ADR) technology. Located in the prolific gold belt of Nevada, Sandman benefits from established infrastructure and a straightforward metallurgical process. The significance of this facility lies in its ability to process 6,000 tonnes per day (tpd) of leachable mineralized material, totaling approximately 19.4 million tonnes over the life of mine. The recovery method begins with open-pit delivery of ore to a stockpile adjacent to the crushing plant. A front-end loader feeds the crusher, where material is reduced to a suitable size fraction. Crushed ore is then transported via haul trucks to a lined heap leach pad, where it is end-dumped and dozer-pushed to the required lift height. A weak cyanide solution is applied to extract precious metals, generating a pregnant solution that is directed to an ADR plant. The ADR plant employs a carbon-in-column (CIC) circuit to adsorb dissolved gold onto activated carbon. Loaded carbon is bagged and shipped off-site for gold recovery, while barren solution is recycled back to the heap. This closed-loop approach minimizes water consumption and environmental impact, underscoring the project’s commitment to sustainable mining practices. The Sandman Gold Property’s recovery methods are optimized for low-cost, high-efficiency gold production, making it a compelling asset in Nevada’s mining landscape.

Key Process Stages

• Stage 1: Crushing and Sizing – Mineralized material is delivered from the open pit to a stockpile and fed via a front-end loader into a conventional crushing plant. The ore is crushed to a suitable size fraction for heap leaching, ensuring optimal particle size distribution for efficient cyanide percolation and gold dissolution.
• Stage 2: Heap Stacking – Crushed material is transported by haul trucks to a lined heap leach pad. Industry-standard end-dumping and dozer pushing are used to stack the ore to the required lift height, creating a permeable heap that supports uniform solution distribution.
• Stage 3: Cyanide Leaching – A weak cyanide solution is applied to the stacked ore through drip emitters or sprinklers. The solution percolates through the heap, dissolving gold and silver into a pregnant solution. Leach parameters are designed to achieve maximum metal extraction over the planned leach cycle.
• Stage 4: Carbon-in-Column (CIC) Adsorption – Pregnant solution from the heap is collected and directed to the ADR plant, which contains a series of carbon columns. Activated carbon adsorbs dissolved gold from the solution as it passes through the CIC circuit. The barren solution is sent to a pond for recycling back to the heap.
• Stage 5: Carbon Processing and Gold Recovery – Loaded carbon from the columns is bagged and transported off-site to an external facility where gold is stripped from the carbon via desorption. The resulting doré is sent to a contract refiner for final refining. Stripped carbon is returned to the site for reuse, closing the reagent loop.

Additional Interesting Data and Summary

Beyond the core flowsheet, the Sandman Gold Property’s recovery methods incorporate several critical technical and operational details. Reagent consumption is estimated at 0.5 kg of sodium cyanide (NaCN) per tonne of ore, based on comparable Nevada operations. Water usage for the heap leach irrigation system is projected at 6.0 to 12.0 liters per second, with the barren solution continuously recycled from the ADR plant, significantly reducing fresh water demand. The total plant power requirement ranges from 2.0 to 3.0 MW, supporting the crushing plant, ADR facility, and ancillary systems. Environmental considerations are integral to the design: the heap leach pad is lined to prevent solution infiltration, and all process solutions are contained within a closed-loop system to minimize environmental footprint. The barren solution pond stores recycled solution for continuous reuse, aligning with best practices for water stewardship in arid Nevada. Economically, the decision to bag loaded carbon and transport it off-site for gold stripping and refining reduces on-site capital expenditure and allows the project to leverage existing third-party infrastructure. The ADR plant’s carbon-in-column circuit ensures efficient gold recovery from pregnant solution, while stripped carbon is returned to the site for sustained reagent efficiency. Sustainability initiatives include the potential expandability of the heap leach pad to accommodate life-of-mine production increases, as noted in the PEA. Future outlook for the Sandman Gold Project is positive, with the low-capex, conventional recovery flowsheet offering operational flexibility and scalability. The use of proven technology—crushing, heap leaching, and carbon adsorption—mitigates technical risk and supports rapid deployment. Borealis Mining Company Limited continues to advance the project toward development, with the recovery methods outlined in the January 2026 PEA forming the foundation for future feasibility studies. The Sandman Gold Property stands as a promising gold asset in Nevada, with recovery methods optimized for cost-effective, environmentally responsible production.

Key Processes: Heap Leaching, Cyanidation, Crushing

Target Commodities: Gold