Thermo Scientific NITON XL3t 500 User Manual page 54

Analysis of Unprepared Samples – In Situ
Mining - Grade Control
1-40 NITON XL3 Analyzer User's Guide
Figure 1-3. Taking a reading from a rockface
Grade Control is the analysis of mined ore for the purpose of assuring that
the metal content of the ore is within desirable limits. Samples are taken
from the lot of ore and tested. The following technique may be used:
• Clean the measurement window of your analyzer before and after taking
a sample to prevent cross-contamination.
• Crush the sample to roughly gravel sized pieces.
• Place the pieces into a cloth bag.
• Take several readings of the bagged sample. For a 7 inch by 12 inch bag,
take at least three sample readings. If the readings vary widely, take more
readings, as the sample is not very homogeneous. The more readings
you take, the more accurate the estimate will be.
• Average the readings.
• Send the samples on for laboratory analysis if the averaged reading looks
interesting.
• Clean the measurement window of your analyzer before and after taking
a sample to prevent cross-contamination.
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