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Santiago Mineral Services CentreA full range of Geochemistry, Metallurgical and Environmental Testing with specialized

expertise in Copper and Gold ores.

Copper and Gold Analytical Services

Evaluation of copper prospects requires knowledge of mineralogy and mineral solubility for metallurgical considerations. The isolation of oxide/carbonate, secondary chalcocite and primary sulfide minerals from total copper is useful in determining leachability of copper in a deposit. This information can be obtained by sequential leaching of the sample. The ALS Santiago Mineral Services Centre houses a purpose built copper leaching laboratory with capability to undertake specialty copper leaches.

Copper Procedures

Copper oxide minerals such as malachite, azurite, chrysocolla and portions of cuprite and tenorite can be leached using sulfuric acid, referred to as “acid soluble” copper. Cyanide leach will dissolve the secondary chalcocite, bornite and a portion of the chalcopyrite content of the sample, while the majority of the sulfide minerals will remain in the residue analyzed at the end of a sequential leach. The mineral dissolution in each leach may vary depending on the sample matrix and specific mineralogy.

ALS provides custom methods using different leach conditions upon request.

• Trace Copper methods and Assay Copper Methods ¾ Aqua regia digestion and ICP or AAS finish ¾ Four acid near total digestion and ICP or AAS finish

• Concentrate Copper methods ¾ HNO3-HCl-H2SO4 acid digestion followed by potentiometric titration ¾ HNO3-HCl-HF-H2SO4 acid digestion followed by volumetric finish

• Mineral selective, sequential Copper leaches ¾ Copper oxide method, citric acid leach and AAS finish ¾ Non-sulphide method, dilute sulphuric acid and AAS finish ¾ Copper oxide, dilute sulphuric acid with sulphur dioxide leach and AAS finish ¾ Copper quick leach ¾ Copper cyanide soluble ¾ Copper sequential analysis: Copper results are reported for sulphuric acid soluble, soluble and total copper.

Sequential analysis: first dilute sulphuric, then cyanide and total performed on residue from prior leach

Copper

ALS Santiago Mineral Services CentreA full range of Geochemistry, Metallurgical and Environmental Testing with specialized expertise in Copper and Gold ores.

Gold and other precious metals continue to be highly sought after by mining and exploration companies. ALS has the analytical tools and years of experience assist with this potentially valuable search. Gold in Drill Core, Rocks and Chip Samples

The ALS Santiago Mineral Services Centre houses a purpose built fire assay laboratory.

Selection of the most appropriate fire assay method for accurate determination of total gold content in a sample is highly dependent on sample matrix, grain size and distribution of the gold and the data objective. A wide variety of minerals and metals (such as chromite, base metal sulfides and oxides, selenides, and tellurides) in moderate to high concentrations can interfere with the fire assay process, generally leading to low precious metal recoveries. With prior knowledge of the presence of these minerals and metals, ALS can modify flux constituents to improve recoveries.

When samples contain high grade or coarse gold occurrences, the screen metallic procedure is recommended to help avoid over- or under-estimating gold grades. Custom method triggers can be set up such that gold over a certain concentration will automatically be re-run using alternative procedures, including screen metallics.

ALS customises gold assay programs to meet client objectives.

Aqua Regia Digestions

The determination of gold in soils and stream sediments by aqua regia digestion offers very low detection limits. The aqua regia procedure is an attractive option for geochemical orientation surveys, or when using stream sediments vector mineralisation. Aqua regia digestion solublizes the portion of gold occurring natively and bound in sulfide ore minerals. Determination by ICPMS increases sensitivity.

Adding Multi-Element Determinations to an Aqua Regia Gold Digestion

Our Super Trace and Trace Level aqua regia gold digestions may be combined with a multi-element package to provide a complete, cost effective and meaningful data set for geologists and geochemists.

Cyanide Leach

Bulk Leach Extractable Gold (BLEG) or cyanide leach procedures are used in grassroots exploration where cyanide extraction from a very large sample (500g to 3kg) can detect trace gold anomalies that otherwise would go unnoticed.

In mining and exploration applications, cyanide leach tests are used to establish the potential cyanide extraction efficiency for gold, silver and copper. Various temperature and cyanide concentration combinations are available. Specific to gold, the preg-rob leach test can identify the tendency of certain ores to re-adsorb gold from the cyanide solution, causing lower recoveries than anticipated. Graphite and certain sulfide minerals such as chalcopyrite can cause preg-robbing behaviour.

Gold

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ALS Santiago Mineral Services CentreA full range of Geochemistry, Metallurgical and Environmental

Testing with specialized expertise in Copper and Gold ores.

Industry leading minerals focused testing, inspection and certification services across the total mine life cycle is now available at the ALS Santiago Minerals Service Centre:

Exploration Services•• Geochemical exploration services •• Onsite sample preparation facilities

•• Geometallurgy •• Advanced mineralogy

•• Scoping stage metallurgical testing

Process Optimisation, Pre-Feasibility & Feasibility Services•• Metallurgical testwork for flowsheet development &

optimisation •• Continuous, bankable pilot plants

•• Ore variability studies •• Geometallurgy

•• Advanced mineralogy •• Marketing sample preparation

Production Support•• Mine site laboratories for grade and mill process control •• Inspection of concentrate, cathode or bullion

•• Oil condition monitoring for the mining fleet •• Environmental analysis for water, soil, tailings

•• Routine process mineralogy

Santiago Mineral Services Centre Hermanos Carrera Pinto 159 Parque Industrial Los Libertadores Colina, Santiago, Chile

T: +56 2 2654 6100 F: +56 2 2654 6163 E: Santiago.MineralServices@alsglobal.com

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