Preparing Liquids And Sludge; Preparing Mining Samples; Specimen Preparation - Fused Glass Disk - Thermo Scientific XL2 User Manual

5
Common Operations

Preparing Mining Samples

Preparing Liquids and Sludge

Liquids
Sludge
Preparing Mining Samples

Specimen Preparation - Fused Glass Disk

64 Niton XL2 Analyzer User's Guide
Fill an XRF sample cup with the liquid to be tested (do not pad the sample with cotton). The
cup must be full so it is best if some liquid is allowed to overflow when the cap is put on.
Sludge can be placed directly into an XRF cup for screening. This is considered in-situ testing
because no attempt has been made to prepare the sample. For more accuracy, the sludge can
be dried, sieved, and ground. Prepare in an XRF sample cup and test the same way you would
with a soil sample. For risk analysis, it is advisable to use a 60-mesh sieve to isolate and test
only fine particles.
Examine the site for differences in surface characteristics before sampling. Valid results depend
on a sufficient and appropriate selection of sites to sample. Incorrect sample collection may
give rise to misleading or meaningless results, regardless of the analysis method. Delineate
sections with different characteristics and treat them as different areas. It may be desirable to
subdivide larger areas even if they have the same characteristics to ensure a thorough
examination. Make certain to label each bag thoroughly. Common information included on
each bag includes the person and/or the company who collected the sample, the location and
area where the sample was taken, and the date the sample was collected.
Prepared sample analysis is the most accurate method for determining the concentration of
elements in a bulk medium using the instrument. Sample preparation will minimize the
effects of moisture, large particle size, variations in particle size and sample non-homogeneity.
Note More sample preparation (drying, milling and sifting) will yield greater accuracy. The
drier, finer, and more homogeneous the particles, the better the measurements.
The samples need to be predried for 2-6 hours in 105°C depending on the moisture content.
1. Grind the dried samples to ~200mesh (74 ?m).
2. Calcination (Ashing) the sample
a. About 4-6 g of dry pulverized sample is calcinated in an alumina or platinum crucible in a
muffle furnace at 1000°C for 1 hour.
b. The sample is cooled in a dedicator and loss on ignition (LOD) is calculated from weight
difference before and after Calcination.
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