A single-step trans-vertical epoxy preparation method for maximising throughput of iron-ore samples via SEM-MLA analysis

Abstract

A novel approach to creating a trans-vertical grain mount embedded in epoxy has been demonstrated through the creation of a new mounting mould, as well as a polisher adapter and sample holder for the Quanta 400 SEM. These rectangular moulds result in a sample that is 30 mm long × 10 mm high × 17 mm wide, thus leading to the ability to polish 10 samples at once. Up to 14 samples may fit in the SEM holder for analysis. This represents an increase in efficiency of over 50%, and with a slow-speed polishing method, the consumables used are reduced by at least a factor of 4. This has the potential to lead to significant financial savings. A comparison of mounting techniques using a −100+200 mesh size fraction of an iron-ore sample from Labrador demonstrates that this new mounting system removes any bias in analysis resulting from density stratification during the sample preparation. These moulds yield similar modal mineralogy abundances and standard deviation as the two-step trans-vertical method, but they are less labour-intensive to make and more efficient to analyse.

Using Random Forest Tree Classification for Evaluating Vertical Cross-Sections in Epoxy Blocks to Get Unbiased Estimates for 3D Mineral Map

“…We suggest that such ideal blocks can be either cubical or rectangular. Grant et al [24] already designed such rectangular prismshaped blocks to expose vertical sections for MLA analyses.…”

High-Throughput Analysis of Offshore Well Drill-Cuttings via SEM-Automated Mineralogy Using Single-Step Trans-Vertical Moulds

“…The standard sample preparation for mineral samples has involved mounting material in a 30-32 mm diameter round epoxy mount and polishing the surface [3]. More recently, trans-vertical mounting has become accepted as a more accurate method for sample preparation in order to avoid bias from density settling [4][5][6][7][8]. A case study is presented here to further support the use of single step trans-vertical mounting to reduce sample bias and increase analysis throughput.…”

Optimization and Quality Control of Automated Quantitative Mineralogy Analysis for Acid Rock Drainage Prediction

“…Test 5: The use of transverse sections is investigated, where the original section is cut vertically and the two halves generated are turned 90 • and mounted in a new resin-encapsulated polished section, exposing the vertical profile of the original section. It is hypothesized that this may reduce or eliminate the effect of particle segregation in the original section (e.g., Kwitko-Ribeiro [42]; Blaskovich [16]; Grant et al [43]). iv.…”