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Portable XRF exploration data is probably most useful where rapid results can be obtained on materials such as diamond core, reverse circulation or rotary air-blast chips and hand samples. It usually forms part of a supporting geological or geometallurgical model when reserves or resources are being reported. The precision of results will vary between units, which are often optimised and calibrated for different elements, and analysis time will also vary between sites and units. Sample heterogeneity is important and averaged multiple analyses may improve representivity. Data can be presented in tables or graphs and it is important that metadata also be stored in order to evaluate the validity of portable XRF data sets. Where the XRF data is to be publicly reported it should be supported by documented, rigorous standardisation and calibration procedures and with chemical analyses by conventional laboratory techniques. JORC (2012) states that other parameters which should be reported include instrument make and model, reading times, and calibrations., Portable XRF exploration data is probably most useful where rapid results can be obtained on materials such as diamond core, reverse circulation or rotary air-blast chips and hand samples. It usually forms part of a supporting geological or geometallurgical model when reserves or resources are being reported. The precision of results will vary between units, which are often optimised and calibrated for different elements, and analysis time will also vary between sites and units. Sample heterogeneity is important and averaged multiple analyses may improve representivity. Data can be presented in tables or graphs and it is important that metadata also be stored in order to evaluate the validity of portable XRF data sets. Where the XRF data is to be publicly reported it should be supported by documented, rigorous standardisation and calibration procedures and with chemical analyses by conventional laboratory techniques. JORC (2012) states that other parameters which should be reported include instrument make and model, reading times, and calibrations.

The Plutonic Gold Mine contains an estimated total resource of 12 200 000 oz of Au, which includes 4 710 000 oz of past production and 2 770 000 oz of reserves and resources. Over 65 000 multi-element analyses of whole-rock core and face channel samples from the underground workings have been carried out by portable X-ray fluorescence (pXRF). A preliminary study based on pXRF analyses from a small number of drill holes found that a geochemical stratigraphy was evident, which strongly controlled the location of Au mineralisation. A much larger pXRF data set is currently being studied, which samples a greater volume of diamond drill core and face channel samples and presents the data in a 3D framework. This data set allows an investigation of the mineralogy of Au mineralisation with varying geochemical associations across the deposit. Historically, there has been a strong relationship identified between As and Au, which has caused issues with metallurgical performance. Utilising seamless data integration of the pXRF data set recognises the different styles of Au mineralisation using elemental concentrations and ratios from the multi-element analyses (Au:As, Au:As:Cu, As:Cu vs. K:V), and allows visualisation of the distribution of these mineralogical associations in 3D., The Plutonic Gold Mine contains an estimated total resource of 12 200 000 oz of Au, which includes 4 710 000 oz of past production and 2 770 000 oz of reserves and resources. Over 65 000 multi-element analyses of whole-rock core and face channel samples from the underground workings have been carried out by portable X-ray fluorescence (pXRF). A preliminary study based on pXRF analyses from a small number of drill holes found that a geochemical stratigraphy was evident, which strongly controlled the location of Au mineralisation. A much larger pXRF data set is currently being studied, which samples a greater volume of diamond drill core and face channel samples and presents the data in a 3D framework. This data set allows an investigation of the mineralogy of Au mineralisation with varying geochemical associations across the deposit. Historically, there has been a strong relationship identified between As and Au, which has caused issues with metallurgical performance. Utilising seamless data integration of the pXRF data set recognises the different styles of Au mineralisation using elemental concentrations and ratios from the multi-element analyses (Au:As, Au:As:Cu, As:Cu vs. K:V), and allows visualisation of the distribution of these mineralogical associations in 3D.

An economic model is developed of the US aluminium market using data from 1960-1978. The model consists of seven stochastic equations and two identities. Stochastic equations are constructed to explain primary supply, new scrap supply, old scrap supply, aggregate consumption, the producer price, the transaction price and the scrap price. Forecasts were made using the model which were close to their actual values, except for the three variables associated with the scrap market. For economic analyses the transaction price, rather than the producer price, is the most relevant., An economic model is developed of the US aluminium market using data from 1960-1978. The model consists of seven stochastic equations and two identities. Stochastic equations are constructed to explain primary supply, new scrap supply, old scrap supply, aggregate consumption, the producer price, the transaction price and the scrap price. Forecasts were made using the model which were close to their actual values, except for the three variables associated with the scrap market. For economic analyses the transaction price, rather than the producer price, is the most relevant.

The amphibolite-facies metabasaltic rocks of the Mine Mafic Package at Plutonic Gold Mine, Western Australia, contain an estimated endowment of 10 500 000 oz Au. A preliminary study based on portable X-ray fluorescence (pXRF) analyses identified a geochemical stratigraphy which strongly controlled the location of Au mineralisation. The present study incorporates a significantly larger pXRF dataset and presents the data in a three-dimensional framework. This dataset allows an investigation of the mineralogy of Au mineralisation with varying geochemical associations across the deposit. Historically, high As content in the mill feed resulted in poor metallurgical performance. Seamless data integration of the pXRF dataset allows for recognition of the different styles of Au mineralisation based on Au/As ratios, and visualisation of the distribution of these different mineralogical associations in three dimensions. This work enables us to predict better the As concentration of underground ore blocks, and to be proactive in optimising the mill configuration to improve metallurgical performance. (Authors.), The amphibolite-facies metabasaltic rocks of the Mine Mafic Package at Plutonic Gold Mine, Western Australia, contain an estimated endowment of 10 500 000 oz Au. A preliminary study based on portable X-ray fluorescence (pXRF) analyses identified a geochemical stratigraphy which strongly controlled the location of Au mineralisation. The present study incorporates a significantly larger pXRF dataset and presents the data in a three-dimensional framework. This dataset allows an investigation of the mineralogy of Au mineralisation with varying geochemical associations across the deposit. Historically, high As content in the mill feed resulted in poor metallurgical performance. Seamless data integration of the pXRF dataset allows for recognition of the different styles of Au mineralisation based on Au/As ratios, and visualisation of the distribution of these different mineralogical associations in three dimensions. This work enables us to predict better the As concentration of underground ore blocks, and to be proactive in optimising the mill configuration to improve metallurgical performance. (Authors.)