The method you choose depends on the stage of your project and your goals. Greenfields exploration using trace element pathfinders generally require the sensitivity and range of ICP-MS methods. Approaches via ICP-AES are suitable for ore body drilling where trace element composition is also required. For more mineralised samples such as massive sulphide ores and concentrates, ICP-AES, XRF and classical chemistry methods are offered.
Geochemical exploration for copper generally uses multi-element methods that produce large suites of trace-elements. These methods are effective as they are useful for not only identifying areas of anomalous copper but also for normalising values against the matrix composition and producing more robust multi-element anomalies. Multi-element geochemistry in residual soil has also been used to map underlying geology.
ALS offer a range of detection limits for multi-element packages by either aqua regia digestion (method codes with 41) or four-acid digestion (method codes with 61). Our super- trace methods are described in the generative exploration section.
Digest | Super Trace Elements | Trace Elements | Low Grade | Mineralised |
---|---|---|---|---|
Aqua Regia | ME-MS41L™ 53 elements 0.01ppm - 1% Cu |
ME-MS41™ 51 elements 0.2ppm - 1% Cu |
ME-ICP41 35 elements 1ppm - 1% Cu |
ME-ICP41a 34 elements 5ppm - 5% Cu |
Four Acid | ME-MS61L™ 48 elements 0.02ppm - 1% Cu |
ME-MS61™ 48 elements 0.2ppm - 1% Cu |
ME-ICP61 33 elements 1ppm - 1% Cu |
ME-ICP61a 33 elements 10ppm - 10% Cu |
Fusion | ME-ICP81 16 elements 20ppm - 30% Cu |
Code | Analytes & ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-MS41™ 0.5g sample |
Ag | 0.01-100 | Cs | 0.05-500 | Mo | 0.05-10,000 | Sr | 0.2-10,000 |
Al | 0.01-25% | Cu | 0.2-10,000 | Na | 0.01%-10% | Ta | 0.01-500 | |
As | 0.1-10,000 | Fe | 0.01%-50% | Nb | 0.05-500 | Te | 0.01-500 | |
Au* | 0.02-25 | Ga | 0.05-10,000 | Ni | 0.2-10,000 | Th | 0.2-10,000 | |
B | 10-10,000 | Ge | 0.05-500 | P | 10-10,000 | Ti | 0.005%-10% | |
Ba | 10-10,000 | Hf | 0.02-500 | Pb | 0.2-10,000 | Tl | 0.02-10,000 | |
Be | 0.05-1,000 | Hg | 0.01-10,000 | Rb | 0.1-10,000 | U | 0.05-10,000 | |
Bi | 0.01-10,000 | In | 0.005-500 | Re | 0.001-50 | V | 1-10,000 | |
Ca | 0.01%-25% | K | 0.01%-10% | S | 0.01%-10% | W | 0.05-10,000 | |
Cd | 0.01-1,000 | La | 0.2-10,000 | Sb | 0.05-10,000 | Y | 0.05-500 | |
Ce | 0.02-500 | Li | 0.1-10,000 | Sc | 0.1-10,000 | Zn | 2-10,000 | |
Co | 0.1-10,000 | Mg | .01%-25% | Se | 0.2-1,000 | Zr | 0.5-500 | |
Cr | 1-10,000 | Mn | 5-50,000 | Sn | 0.2-500 |
Code | Analytes & ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-MS61™ 0.25g sample |
Ag | 0.01-100 | Cu | 0.2-10,000 | Na | 0.01%-10% | Sr | 0.2-10,000 |
Al | 0.01%-50% | Fe | 0.01%-50% | Nb | 0.1-500 | Ta | 0.05-500 | |
As | 0.2-10,000 | Ga | 0.05-10,000 | Ni | 0.2-10,000 | Te | 0.05-500 | |
Ba | 10-10,000 | Ge | 0.05-500 | P | 10-10,000 | Th | 0.01-10,000 | |
Be | 0.05-1,000 | Hf | 0.1-500 | Pb | 0.5-10,000 | Ti | 0.005%-10% | |
Bi | 0.01-10,000 | In | 0.005-500 | Rb | 0.1-10,000 | Tl | 0.02-10,000 | |
Ca | 0.01%-50% | K | 0.01%-10% | Re | 0.002-50 | U | 0.1-10,000 | |
Cd | 0.02-1,000 | La | 0.5-10,000 | S | 0.01%-10% | V | 1-10,000 | |
Ce | 0.01-500 | Li | 0.2-10,000 | Sb | 0.05-10,000 | W | 0.1-10,000 | |
Co | 0.1-10,000 | Mg | 0.01%-50% | Sc | 0.1-10,000 | Y | 0.1-500 | |
Cr | 1-10,000 | Mn | 5-100,000 | Se | 1-1,000 | Zn | 2-10,000 | |
Cs | 0.05-500 | Mo | 0.05-10,000 | Sn | 0.2-500 | Zr | 0.5-500 |
Code | Analytes & ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-ICP41 0.5g sample |
Ag | 0.2-100 | Co | 1-10,000 | Mg | 0.01%-25% | Sc | 1-10,000 |
Al | 0.01%-25% | Cr | 1-10,000 | Mn | 5-50,000 | Sr | 1-10,000 | |
As | 2-10,000 | Cu | 1-10,000 | Mo | 1-10,000 | Th | 20-10,000 | |
B | 10-10,000 | Fe | 0.01%-50% | Na | 0.01%-10% | Ti | 0.01%-10% | |
Ba | 10-10,000 | Ga | 10-10,000 | Ni | 1-10,000 | Tl | 10-10,000 | |
Be | 0.5-1,000 | Hg | 1-10,000 | P | 10-10,000 | U | 10-10,000 | |
Bi | 2-10,000 | K | 0.01%-10% | Pb | 2-10,000 | V | 1-10,000 | |
Ca | 0.01%-25% | Li | 10-10,000 | S | 0.01%-10% | W | 10-10,000 | |
Cd | 0.5-1,000 | La | 10-10,000 | Sb | 2-10,000 | Zn | 2-10,000 |
Code | Analytes & ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-ICP61 0.25g sample |
Ag | 0.5-100 | Cr | 1-10,000 | Mo | 1-10,000 | Th | 20-10,000 |
Al | 0.01%-50% | Cu | 1-10,000 | Na | 0.01%-10% | Ti | 0.01%-10% | |
As | 5-10,000 | Fe | 0.01%-50% | Ni | 1-10,000 | Tl | 10-10,000 | |
Ba | 10-10,000 | Ga | 10-10,000 | P | 10-10,000 | U | 10-10,000 | |
Be | 0.5-1,000 | K | 0.01%-10% | Pb | 2-10,000 | V | 1-10,000 | |
Bi | 2-10,000 | Li | 10-10,000 | S | 0.01%-10% | W | 10-10,000 | |
Ca | 0.01%-50% | La | 10-10,000 | Sb | 5-10,000 | Zn | 2-10,000 | |
Cd | 0.5-1,000 | Mg | 0.01%-50% | Sc | 1-10,000 | |||
Co | 1-10,000 | Mn | 5-100,000 | Sr | 1-10,000 |
Sample analysis for resource definition and grade control requires upper detection limits that can cover the full range of grades. Method selection includes the choice of digestion which can be influenced by the metallurgical extraction process to provide an estimate of the extractable component in addition to the total copper concentration. Copper can be determined as a standalone element or within a multi-element method. Even at the resource estimation or grade control stages multi-element geochemistry can provide valuable data by providing information on deleterious elements present in the ore, or for routine geometallurgical assessment.
High grade copper ore analyses are available by ICP-AES or AAS after either four-acid or aqua regia digestion. These may also be set as automatic over-range assays for exploration samples with high copper content.
Code | Analytes & ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-ICP41a 0.4g sample |
Ag | 1-200 | Cr | 5-50,000 | Mo | 5-50,000 | Th | 100-50,000 |
Al | 0.05%-50% | Cu | 5-50,000 | Na | 0.05%-50% | Ti | 0.05%-50% | |
As | 10-100,000 | Fe | 0.05%-50% | Ni | 5-50,000 | Tl | 50-50,000 | |
Ba | 50-50,000 | Ga | 50-50,000 | P | 50-50,000 | U | 50-50,000 | |
Be | 5-500 | Hg | 5-50,000 | Pb | 10-50,000 | V | 5-50,000 | |
Bi | 10-50,000 | K | 0.05%-50% | S | 0.05%-10% | W | 50-50,000 | |
Ca | 0.05%-50% | La | 50-50,000 | Sb | 10-50,000 | Zn | 10-50,000 | |
Cd | 5-2,500 | Mg | 0.05%-50% | Sc | 5-50,000 | |||
Co | 5-50,000 | Mn | 25-50,000 | Sr | 5-50,000 |
Code | Analytes & ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-ICP61a 0.4g sample |
Ag | 1-200 | Cr | 10-100,000 | Na | 0.05%-30% | Ti | 0.05%-30% |
Al | 0.05%-30% | Cu | 10-100,000 | Ni | 10-100,000 | Tl | 50-50,000 | |
As | 50-100,000 | Fe | 0.05%-50% | P | 50-100,000 | U | 50-50,000 | |
Ba | 50-50,000 | Ga | 50-50,000 | Pb | 20-100,000 | V | 10-100,000 | |
Be | 10-10,000 | K | 0.1%-30% | S | 0.05%-10% | W | 50-50,000 | |
Bi | 20-50,000 | La | 50-50,000 | Sb | 50-50,000 | Zn | 20-100,000 | |
Ca | 0.05%-50% | Mg | 0.05%-50% | Sc | 10-50,000 | |||
Cd | 10-10,000 | Mn | 10-100,000 | Sr | 10-100,000 | |||
Co | 10-50,000 | Mo | 10-50,000 | Th | 50-50,000 |
Code | Analytes | Ranges (%) | Description |
---|---|---|---|
Cu-OG46 | Cu Assay | 0.001-50 | Aqua regia digestion and ICP finish. 0.4g sample |
Cu-OG62 | Cu Assay | 0.001-50 | Four acid digestion and ICP finish. 0.4g sample |
When copper is present in its native form sample preparation and analysis may need to be adapted. As native copper is malleable it is prone to smearing on preparation equipment which will decrease the amount of copper in the sample and add copper to samples prepared afterwards. An option is available to add barren washes after samples with native copper and analyse the copper concentration in the wash. This can give an indication of how much copper is being lost and carried over to following samples.
Metallic screen analysis is recommended for samples that contain native copper as the native copper may not be homogenously distributed through a prepared sample. Samples are screened, a portion of the material passing through the screen is analysed and the entire portion of the material remaining is assayed. With these results an estimate of the total copper concentration of the sample is derived, and the entire coarse fraction contribution determined.
Code | Analytes | Ranges (%) | Description |
---|---|---|---|
Cu_SCR21 | Native Cu | 0.01-100 | Screen 1kg sample to 100 microns, duplicate assay on 0.25g of undersize fraction and assay of entire oversize fraction by four acid digestion and AAS finish. |
Methods for copper concentrates are available with upper detection limits of 100% and a high degree of precision.
ALS offers HNO3-HCl-HF-H2SO4 digestion followed by measurement of Cu by titration. The method Cu-VOL61 method provides a single analysis while Cu-CON02 provides duplicate analyses.
Code | Analytes | Ranges (%) | Description |
---|---|---|---|
Cu-VOL61 Cu-CON02 |
Cu Concentrate | 0.01-100 | HNO3-HCl-HF-H2SO4 acid digestion followed by titration. Cu-CON02 performed in duplicate. 2g sample |
Mineral-selective leaches for copper can be useful at many different stages in a project's life. Some understanding of the recovery from common processing methods may be valuable during resource evaluation. Established mines may want to produce early metallurgical characterisation with geochemistry during resource extension or infill drilling.
ALS offers a citric acid leach (Cu-AA04) which targets oxide minerals and is often used in heap leach and bioleaching extraction. Sulphuric acid digestion (Cu-AA05) also targets oxide minerals and is widely used in copper hydrometallurgical processes. A cyanide leach (Cu- AA17) targets secondary sulphides and some primary sulphide minerals. Cyanide methods are useful when a project contains gold as it is effectively extracted. Other options available are listed in the table below:
Code | Analytes | Ranges (%) | Description |
---|---|---|---|
Cu-AA04 | Cu | 0.01-10 | Citric acid leach and AAS finish. 0.25g sample |
Cu-AA05 | Cu | 0.01-10 | Sulphuric acid leach and AAS finish. 1g sample |
Cu-AA07n | Cu | 0.001-100 | Sulphuric acid/Na sulfite leach and AAS finish. 1g sample |
Cu-AA08q | Cu | 0.001-100 | Sulphuric acid/ferric sulphate leach and AAS finish. 1g sample |
Cu-AA17 | Cu | 0.001-10 | Cyanide leach and AAS finish. 2g sample |
Cu-PKG06LI | Cu | Various | Sequential leach for oxide, sulphide and residual Cu. Various options available. 1g sample |
Multi-element analysis for high sulphide samples generally requires the use of a strong oxidising agent to break down all sulphides in the sample. These methods are offered from both fusion and acid decomposition methods.
ALS offers a wide range of analytical methods for exploration applications regardless of sample media.
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