Photothermal method for in situ microanalysis of the chemical composition of coal samples

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:865865

Amer, Nabil M ^[1]

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1. Berkeley, CA

Successive minute regions (13) along a scan path on a coal sample (11) are individually analyzed, at a series of different depths if desired, to determine chemical composition including the locations, sizes and distributions of different maceral inclusions (12). A sequence of infrared light pulses (17) of progressively changing wavelengths is directed into each minute region (13) and a probe light beam (22) is directed along the sample surface (21) adjacent the region (13). Infrared wavelengths at which strong absorption occurs in the region (13) are identified by detecting the resulting deflections (.phi.) of the probe beam (22) caused by thermally induced index of refraction changes in the air or other medium (19) adjacent the region (13). The detected peak absorption wavelengths are correlated with known characteristic peak absorption wavelengths of specific coal constituents to identify the composition of each such minute region (13) of the sample (11). The method enables rapid, convenient and non-destructive analyses of coal specimens to facilitate mining, processing and utilization of coals.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• DOE Contract Number: AC03-76SF00098
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4591718
• OSTI ID: 865865
• Country of Publication: United States
• Language: English

Related Subjects

photothermal
method
situ
microanalysis
chemical
composition
coal
samples
successive
minute
regions
13
scan
path
sample
11
individually
analyzed
series
depths
desired
determine
including
locations
sizes
distributions
maceral
inclusions
12
sequence
infrared
light
pulses
17
progressively
changing
wavelengths
directed
region
probe
beam
22
surface
21
adjacent
strong
absorption
occurs
identified
detecting
resulting
deflections
phi
caused
thermally
induced
index
refraction
changes
air
medium
19
detected
peak
correlated
characteristic
specific
constituents
identify
enables
rapid
convenient
non-destructive
analyses
specimens
facilitate
mining
processing
utilization
coals
sample surface
method enables
infrared light
chemical composition
thermally induced
probe beam
light pulses
light beam
light pulse
composition including
scan path
probe light
coal samples
coal sample
minute region
minute regions
absorption wavelength
photothermal method
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