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Thermomagnetometry and evolved gas analysis in the identification of organic and pyritic sulphur in coal and oil shale
ThermochimicaActa, 93 (1985) 745-748 Elsevier Science Publishers B.V., hsterdam
THERMOMAGNETOMETRY AND EVOLVED GAS ANALYSIS IN THE IDENTIFICATION OF ORGANIC AND PYRITIC SULPHUR IN COAL AND OIL SHALE
S.5t.J.
Warne,
The
New South A.J. British
University
Wales
Bloodworth
Geological
and
Newcastle,
Australia D.J.Morgan,
64/78
Survey.
London
of
2308,
WClX 8NG.
Gray’s
Inn
Road,
UK
ABSTRACT Potential difficulties of using a new TG/TM technique for measuring syrite content of coals that also contain slderite are discussed briefly. Direct measurement of the SO2 evolved on heating pyrite in an oxidizing atmosphere is a possible alternative and this may also provide information amounts of organic sulphur in the coal
the
on
I NTRODUCT I ON a new technique
Recently, metry of
method
the
with
pyrite
proximate
(FeS2)
to
to
It
Fe-oxides
from
other
than
pyrite
Fe)(CO
) 32
are
)
mass
a serious
(61,
are
of
in
the
for
IS
oxrdizing
proceedings
the
coals
of
ICTA
been
present other
stable
in
Hz,
of the
in
mass
O2 the
original
resrdual shown
Siderlte
and
(4,5),
these will
ankerite
not
coals
(Ca(Mg,
as*the
non-magnetic
should
be
phases
although is
mineral
when
American
Fe-yielding
of
decomposes
content For
is
content
(3) and, pyrrte Fe.
ash
gain
(FeC03)
that
ankerrte
the
pyrite
siderite
high
(4)
conventional in
pyrite
countries
product
therefore, coal
and,
scope
as
the
thermo-analytical
direct
has
determination
oxidation
that
as
Hz-reduced
it
generally
also
analysis
atmosphere.
of
the as
range
the
Following
the
(2)
a spuriously
coal,
of
to
out
for
dicalcium
affect
the
pyrite.
still,
determination potential
is
related
pointed
decomposition
which
is
not
be
(1). pyrite
On reheating
temperature in
gain
common in
TM determination There
same
problem
Fe-bearing
ferrite
can
analysis/thermogravi-
established
coals from
Hp.
been
proximate
been
American
flowing
together
the
IS not
ultimate
the
the
has
resulting
23
In
however,
occur
this
of
Fe D
Fe oxidation
has, within
two minerals obtained
Fe
to
coal.
method
content the
metallic
corresponding the
thermomagnetometry
analysis.
reduced
combining
85,
Bratislava
research
SO2 evolved
on 011
shales
Into
of
techniques
of
Studies
for
utilization
coal is
from In
new methods generally
for
pyrite
involves
heat,
considerable. pyrite
the
One such
on heatrng
BGS laboratories
in
an
using
non-
- 746 -
dispersive is
IR detectors
a promising
on the
to
method
amount
of
measure
which
sulphur
has
bound
evolved
the
by the
MATERIALS Materials Klmmeridge from
examined
Clay
Formatton
a locality
obtalned
the
(2.1
three
under
N2:02)
gas the
of
which
on
and the
in
a suite
the
through
of
evolution
shown
that
providing
(‘organic
The
of
this
information S’).
the
Jurassic
Permian
bituminous
CO) evolution
material
in
coals
profiles gas
non-dispersive
IR detectors calibrated
were
evolved
were
a flowing
detectors
volatiles
curves
from
CO2.
powdered
series.
amounts
shale
(SO2,
passed
arranged
mixtures
peaks
then
of
fraction
oil
UK and
layer
have
of
AND METHODS
low-grade
the
benefit
organic
Volatile
a thin
volatiles
standard
a
in Australia.
by heating
stream
were
(7)
volattles
additional
calculated
for using
from
areas
(7)
RESULTS Volatile profile The
evolution
shows
complex
reactlons the
The
pyrite
line
and
the
It
combustron. is
at
ohyslcally The
under
laboratory
profl for
on the
the
at
with
CO2 and
exposed
organic
on both
N2)
However ,
evolution of
of
S in Figs.
an appreciably
2a and
the
of
the of
the
peaks
(Ftg.
1
Zb), the The
b could
lower
are are
to
The
organic
so2
S.
oxidation below
for
the
the
oxidation
and
organic
above
S reaction
.
in
on Fig.
on the
Figs. on
1 and
the
2 that than
rate
of
evolution coal
rate
the
that
2 strongly of
carbon
volume
of
coal
(Fig.
matched lacking
although
2a)
of
SD2 and
CO;/CO so may
large,
sharp to
initial range
peak
pyrrte
than
In
combustion of
coal
exposure
the
sharp
low-temperature
sharp
volatile
peak
that
shale.
on the
occurs
if Thus
the
SO2
profiles
assigned
SO2 profrle but,
to
peak
evolution
broad as
on the
oil
a fresh
further
day’s
oxidation the
is
four
by an equally on the
an
be due
carbon profiles
after
same temperature
temperature
of
+ 8~0~
greater
volatile
CO profiles
related
SO2 evolved
1.
sample
thesame fresh
is
basis
Fig
of
of
dependant
scale
in
oxidation
profiles is
magnitude the
the
2Fe203
CO,/CO
SO2 evolution
In
within Fig.
of
SO2 from
these
coal
profile
from
those
atmosphere.
le.
SO2 and
shown
was obtained
on
SO2 evolution
by comparison
(stored
qeaks
the
dependence
Illustrated
+ 1 102+
an order
least
are
amount
0.15%
4FeS2
may be seen
‘flush’
of
the
content
the
shale
3OO’C representing _\ system above 35O’C
pyrrte
of
oil
at
a value
the
rate
the
By measuring
Frg.1,
for
for
peak
between
that
evolved
peak
(8).
In
1.5%
similarity
suggests
inltral
SO2 evolution of
dashed
content
an
profiles
on the to
at so. is
-380’~ It
SO2
oxidation
occurs
a consequ-
- 747 -
ence
of
the
the
sample
rate
strongly
exothermic
temperature
used,
with
to
nature
rbse
a subsequent
much loss
probably
necessary
to
differentiate
inorganic
(pyrite)
S.
However,
under
the
SO2 evolution
agreement
with
total
the
limited
of
the
faster
of
the
profiles
for
S (organic
and
for the
oxidation
programmed
strict
between values
carbon
than
which at
temperature
the
causes
heating
control
which
the
SO2 generated
from
organic
total
S determined
from
the
seven
coals
inorganic)
examined
values
showed
determlned
is and
areas
good
chemically
3).
(Fig
CONCLUSIONS From ated
on
heating
reasonably
results
coal
values
or
for
dlfferentlating
oil
but
by
the
rate
It
of
the
organic
combustion
release
of
Inorganic
S
that from
material.
causes
oxidation
applied
IS apparent
of
pyrite Work
and
to the
the In
a rapld
IS
and
an oxidizing but
configuration
addition,
increase
of the
in
sample
merging to
markedly
resolve
ACKNOWLEDGMENTS We thank Dr D.J.Swalne, and their analyses. This work was carrfed research worker at the British Geological permisslon of the Dtrector, BGS (NERC).
this
these
may
is
markedly from
exothermrc
SO2 peaks
help
to
to
organrc
some
affected combustion
nature
resulting due
in
Peak
CO resulting
temperature, of
SO2 genergive
be experienced
contents. profile
of
CD2 and
of
should
may
sulphur
SO2 evolution
the
analysis
atmosphere
difficulties
inorganic
sample
consequent
continuing
continuous
above,
in
S contents
organic
techniques
extent
shale
total
between
deconvolutlon
recorded
of in
this
premature and
problems
CSIRO, Australia out while SStJW Survey. AJB and
for the coal samples was a visiting DJM publish with
REFERENCES
1. :: 4 5.
6
D.M. Aylmer & M.W Row, Thermochim. Acta, 78 (1984) 81. S.St.J.Warne, Thermochim. Acta (submltted). S.St. J.Warne D.H.French, Thermochim Acta. 76 (1984) 179. H.J.Gluskoter, V.F.Shimp & R R Ruth, pp. 369-424 in “Chemistry of Coal Utilization”, 2nd Suppl. Vol., ed. M A.Elliott, Waley (1981). E.Stach, M-Th. Mackowsky, M.Teichmuller, G H.Taylor, D.Chandra & R.Teichmul ler, “Stach’s Textbook of Coal Petrology” 2nd Edn. Borntraeger, Berl in (1975). 428~~. A.E.Milodowskl 6 D.J.Morgan, “Proc. 2nd Europ. Symp. Thermal Anal”. Heyden, London (1981). 468. D J.Morgan, Anal. Proc. Royal Sot Chem., 21 (1984) 3 A.J.Bloodworth 8 D J.Morgan, in preparation.
- 740 -
R2.2b I-J
J
I i , * 09 so
-J
*.t-
I
0.0
l
0.5
1.0
1.5
2.0
%MlR 5otctW)
FIG.1.
Volahile evolution profiles for oil shale Sample weight 119 rate 10 C/min, carrier gas 2:l N2:02 at 300 ml/min. Sensitivity of detectors : CO2, CO 10,000 porn fsd; SO2 1000 ppm fsd.
FIG.2.
Volatile evolution coals. Sample weight
FIG.3.
Total S from chemical bituminous coals.
profiles 70 mg,
of other
analysis
(a) ‘fresh’ experimental vs.
total
and (b) details S frcm
mg, heating ranges
‘exposed’ bituminous as in Fig. 1.
SO2 evolution
curves
for
THERMOMAGNETOMETRY AND EVOLVED GAS ANALYSIS IN THE IDENTIFICATION OF ORGANIC AND PYRITIC SULPHUR IN COAL AND OIL SHALE
S.5t.J.
Warne,
The
New South A.J. British
University
Wales
Bloodworth
Geological
and
Newcastle,
Australia D.J.Morgan,
64/78
Survey.
London
of
2308,
WClX 8NG.
Gray’s
Inn
Road,
UK
ABSTRACT Potential difficulties of using a new TG/TM technique for measuring syrite content of coals that also contain slderite are discussed briefly. Direct measurement of the SO2 evolved on heating pyrite in an oxidizing atmosphere is a possible alternative and this may also provide information amounts of organic sulphur in the coal
the
on
I NTRODUCT I ON a new technique
Recently, metry of
method
the
with
pyrite
proximate
(FeS2)
to
to
It
Fe-oxides
from
other
than
pyrite
Fe)(CO
) 32
are
)
mass
a serious
(61,
are
of
in
the
for
IS
oxrdizing
proceedings
the
coals
of
ICTA
been
present other
stable
in
Hz,
of the
in
mass
O2 the
original
resrdual shown
Siderlte
and
(4,5),
these will
ankerite
not
coals
(Ca(Mg,
as*the
non-magnetic
should
be
phases
although is
mineral
when
American
Fe-yielding
of
decomposes
content For
is
content
(3) and, pyrrte Fe.
ash
gain
(FeC03)
that
ankerrte
the
pyrite
siderite
high
(4)
conventional in
pyrite
countries
product
therefore, coal
and,
scope
as
the
thermo-analytical
direct
has
determination
oxidation
that
as
Hz-reduced
it
generally
also
analysis
atmosphere.
of
the as
range
the
Following
the
(2)
a spuriously
coal,
of
to
out
for
dicalcium
affect
the
pyrite.
still,
determination potential
is
related
pointed
decomposition
which
is
not
be
(1). pyrite
On reheating
temperature in
gain
common in
TM determination There
same
problem
Fe-bearing
ferrite
can
analysis/thermogravi-
established
coals from
Hp.
been
proximate
been
American
flowing
together
the
IS not
ultimate
the
the
has
resulting
23
In
however,
occur
this
of
Fe D
Fe oxidation
has, within
two minerals obtained
Fe
to
coal.
method
content the
metallic
corresponding the
thermomagnetometry
analysis.
reduced
combining
85,
Bratislava
research
SO2 evolved
on 011
shales
Into
of
techniques
of
Studies
for
utilization
coal is
from In
new methods generally
for
pyrite
involves
heat,
considerable. pyrite
the
One such
on heatrng
BGS laboratories
in
an
using
non-
- 746 -
dispersive is
IR detectors
a promising
on the
to
method
amount
of
measure
which
sulphur
has
bound
evolved
the
by the
MATERIALS Materials Klmmeridge from
examined
Clay
Formatton
a locality
obtalned
the
(2.1
three
under
N2:02)
gas the
of
which
on
and the
in
a suite
the
through
of
evolution
shown
that
providing
(‘organic
The
of
this
information S’).
the
Jurassic
Permian
bituminous
CO) evolution
material
in
coals
profiles gas
non-dispersive
IR detectors calibrated
were
evolved
were
a flowing
detectors
volatiles
curves
from
CO2.
powdered
series.
amounts
shale
(SO2,
passed
arranged
mixtures
peaks
then
of
fraction
oil
UK and
layer
have
of
AND METHODS
low-grade
the
benefit
organic
Volatile
a thin
volatiles
standard
a
in Australia.
by heating
stream
were
(7)
volattles
additional
calculated
for using
from
areas
(7)
RESULTS Volatile profile The
evolution
shows
complex
reactlons the
The
pyrite
line
and
the
It
combustron. is
at
ohyslcally The
under
laboratory
profl for
on the
the
at
with
CO2 and
exposed
organic
on both
N2)
However ,
evolution of
of
S in Figs.
an appreciably
2a and
the
of
the of
the
peaks
(Ftg.
1
Zb), the The
b could
lower
are are
to
The
organic
so2
S.
oxidation below
for
the
the
oxidation
and
organic
above
S reaction
.
in
on Fig.
on the
Figs. on
1 and
the
2 that than
rate
of
evolution coal
rate
the
that
2 strongly of
carbon
volume
of
coal
(Fig.
matched lacking
although
2a)
of
SD2 and
CO;/CO so may
large,
sharp to
initial range
peak
pyrrte
than
In
combustion of
coal
exposure
the
sharp
low-temperature
sharp
volatile
peak
that
shale.
on the
occurs
if Thus
the
SO2
profiles
assigned
SO2 profrle but,
to
peak
evolution
broad as
on the
oil
a fresh
further
day’s
oxidation the
is
four
by an equally on the
an
be due
carbon profiles
after
same temperature
temperature
of
+ 8~0~
greater
volatile
CO profiles
related
SO2 evolved
1.
sample
thesame fresh
is
basis
Fig
of
of
dependant
scale
in
oxidation
profiles is
magnitude the
the
2Fe203
CO,/CO
SO2 evolution
In
within Fig.
of
SO2 from
these
coal
profile
from
those
atmosphere.
le.
SO2 and
shown
was obtained
on
SO2 evolution
by comparison
(stored
qeaks
the
dependence
Illustrated
+ 1 102+
an order
least
are
amount
0.15%
4FeS2
may be seen
‘flush’
of
the
content
the
shale
3OO’C representing _\ system above 35O’C
pyrrte
of
oil
at
a value
the
rate
the
By measuring
Frg.1,
for
for
peak
between
that
evolved
peak
(8).
In
1.5%
similarity
suggests
inltral
SO2 evolution of
dashed
content
an
profiles
on the to
at so. is
-380’~ It
SO2
oxidation
occurs
a consequ-
- 747 -
ence
of
the
the
sample
rate
strongly
exothermic
temperature
used,
with
to
nature
rbse
a subsequent
much loss
probably
necessary
to
differentiate
inorganic
(pyrite)
S.
However,
under
the
SO2 evolution
agreement
with
total
the
limited
of
the
faster
of
the
profiles
for
S (organic
and
for the
oxidation
programmed
strict
between values
carbon
than
which at
temperature
the
causes
heating
control
which
the
SO2 generated
from
organic
total
S determined
from
the
seven
coals
inorganic)
examined
values
showed
determlned
is and
areas
good
chemically
3).
(Fig
CONCLUSIONS From ated
on
heating
reasonably
results
coal
values
or
for
dlfferentlating
oil
but
by
the
rate
It
of
the
organic
combustion
release
of
Inorganic
S
that from
material.
causes
oxidation
applied
IS apparent
of
pyrite Work
and
to the
the In
a rapld
IS
and
an oxidizing but
configuration
addition,
increase
of the
in
sample
merging to
markedly
resolve
ACKNOWLEDGMENTS We thank Dr D.J.Swalne, and their analyses. This work was carrfed research worker at the British Geological permisslon of the Dtrector, BGS (NERC).
this
these
may
is
markedly from
exothermrc
SO2 peaks
help
to
to
organrc
some
affected combustion
nature
resulting due
in
Peak
CO resulting
temperature, of
SO2 genergive
be experienced
contents. profile
of
CD2 and
of
should
may
sulphur
SO2 evolution
the
analysis
atmosphere
difficulties
inorganic
sample
consequent
continuing
continuous
above,
in
S contents
organic
techniques
extent
shale
total
between
deconvolutlon
recorded
of in
this
premature and
problems
CSIRO, Australia out while SStJW Survey. AJB and
for the coal samples was a visiting DJM publish with
REFERENCES
1. :: 4 5.
6
D.M. Aylmer & M.W Row, Thermochim. Acta, 78 (1984) 81. S.St.J.Warne, Thermochim. Acta (submltted). S.St. J.Warne D.H.French, Thermochim Acta. 76 (1984) 179. H.J.Gluskoter, V.F.Shimp & R R Ruth, pp. 369-424 in “Chemistry of Coal Utilization”, 2nd Suppl. Vol., ed. M A.Elliott, Waley (1981). E.Stach, M-Th. Mackowsky, M.Teichmuller, G H.Taylor, D.Chandra & R.Teichmul ler, “Stach’s Textbook of Coal Petrology” 2nd Edn. Borntraeger, Berl in (1975). 428~~. A.E.Milodowskl 6 D.J.Morgan, “Proc. 2nd Europ. Symp. Thermal Anal”. Heyden, London (1981). 468. D J.Morgan, Anal. Proc. Royal Sot Chem., 21 (1984) 3 A.J.Bloodworth 8 D J.Morgan, in preparation.
- 740 -
R2.2b I-J
J
I i , * 09 so
-J
*.t-
I
0.0
l
0.5
1.0
1.5
2.0
%MlR 5otctW)
FIG.1.
Volahile evolution profiles for oil shale Sample weight 119 rate 10 C/min, carrier gas 2:l N2:02 at 300 ml/min. Sensitivity of detectors : CO2, CO 10,000 porn fsd; SO2 1000 ppm fsd.
FIG.2.
Volatile evolution coals. Sample weight
FIG.3.
Total S from chemical bituminous coals.
profiles 70 mg,
of other
analysis
(a) ‘fresh’ experimental vs.
total
and (b) details S frcm
mg, heating ranges
‘exposed’ bituminous as in Fig. 1.
SO2 evolution
curves
for