Eurofins Labtium offers a comprehensive suite of methods for different grade control samples
The reliable analysis of ore grade in selective mining is crucial for optimisation of blasting, excavation, classification and stockpiling of the ore and waste rock and blending of the feed to the processing plant.
The analyses of total concentrations do not always provide the best information for these critical decisions. In some mineralisation types knowing the concentration of the commodity element in the actual, feasible mineralogical phase will give better basis also for the optimisation of the subsequent metallurgical processes. Additionally the concentration of main and deleterious elements and minerals which may affect the quality and efficiency of ore processing are important also during ore delineation.
The choice of assaying method is thus a very challenging task which directly affects the productivity and profitability of a mine. Labtium specialists can guide you to find the best method to fit the objectives of your project.
For gold ores either traditional Fire assay or cyanidation methods can be used. Classical Fire assay methods give the total gold content in the sample, whereas cyanidation leache dissolve only free, metallic gold and is of benefit also in the metallurgical testing. For cyanide soluble gold we recommend Labtium method 236A which involves simultaneous pulverizing and leaching using the PAL1000-machine and LeachWell® -accelerator. The Fire assay pre-concentration/separation method for gold is complemented either with AAS or ICP-OES finish (704A/P and 705A/P). Additionally, Pd and Pt can be analysed with the ICP-OES-method. In some gold ore types the aqua regia based methods can also be used.
For base metal ores several analytical methods are available. For example for Ni- and Cu-ores we recommend aqua regia leach with ICP-OES finish (method 510P), and for Pb-Zn-ores sodium peroxide fusion with ICP-OES finish (method 720P).
An XRF-method using a bench top-ED-XRF-spectrometer can also be used for a broad variety of elements with very fast turn-around times.
The base metal assays can also be supplemented by chemical phase analyses like sulphide selective leaches for low-grade Ni-deposits where nickel in sulphides and silicates has to be evaluated.
The analysis of grade control samples may have to be complemented with element-specific, individual method. These methods include high -grade sulphur -, carbon-, Hg-analyses, physical parameters like loss-on-ignition, specific gravity, saturation magnetisation (Satmagan for analysing mixtures of magnetic and non-magnetic components) etc (See Additional analyses).