"الملف 35/64 III المعادن في عُمان. أبحاث علماء جيولوجيا مدرساي" [ظ‎‎١‎٧] (٢٧٦/٤٣)

Assam. 9
Calorific power.
Fixed carbon.
Volatile matter
and moisture.
Ash.
1.
Makum
... 6853
53-28
45-45
1-02
2.
Do.
... 7205
47*84
48-50
3-66
3.
Cherrapunji
... 7702
49-54
45-72
4-74
4.
Maoflong
... 7128
49-79
47-25
2-96
5.
Dikhu valley
... 6028
51-40
46525
2-35
6.
Telpung
?
61-6
35-2
3-2
7.
Sur coal
... 7846
62*78
35-49
1-71
A few more remarks with reference to the comparative amount of asb
Very little and heating power in Sur coal may be appropriate,
ash.
Out of 28 samples of Upper Assam coals tested by Mr. Mallet (Memoirs
Comparison Geo1 - Survey, Vol. XII, Part 2, page 80), 5 only have a smaller
with Assam percentage of ash than Sur coal, the rest a higher one.
coals. 0
A list of 43 assays of various British coals published in <f Elements of
Comparison Metallurgy " by F. Arthur Phillips, 3rd edition, page 51, eon-
with British tains 9 coals only, which have a smaller percentage of ash than
coals - Sur coal.
Of 52 assays of various Bengal coals published in the Agricultural
Comparison ledger, 1898, No. 14, pages 23 to 31, not one can be compared
with Bengal with Sur coal, the lowest percentage of ash recorded in this
coaL list being 5-35^.
Sur coal, therefore, may be said to give considerably less ash than Bengal
coal and to he equal to the best Assam and British coals as regards ash.
One sample ^B. 87) of a composition similar to the average was tested as to
High calorific its calorific power, and the result obtained was 7846 calories.
power. Xhe calorific power of Sur coal is little below that of the best
British coals and superior to that of Bengal coals.
Por comparison: *
Calorific power of 5 British coals, according to Pay en's Industrial
Chemistry, 1878, page 89
Welsh coal ... ... ... _ 8161 calories.
Newcastle coal
Scotch „
Derbyshire „
Lancashire „
... 8126 „
7771 „
... 7596 „
7621 „
Calorific power of 5 Assam coals, according to Agricultural Ledger, e.c.—
Makum coal ... ... ... ... 6853 calories.
... 7205 „
... 7702 „
7128 „
... 6028 „
Highest calorific power received by testing 52 samples of various Bengal
coals, according to Agricultural Ledger, e.c.—7183 calories.
Sur coal is remarkably free from sulphur. No iron pyrites were observed.
Very little but the coal is impregnated with a small amount of hydrous
iron oxyde, resulting no doubt from the decomposition of iron
pyrites.
,. 10 samples assayed, 6 gave a white ash, in 2 only the ash shows
a distinct brown colouring, while two are buff coloured.
Do.
Cherrapunji coal
Maoflong )}
Dikhu valley „
• Assays 1 to 5 from the Agricultural Ledger, 1898, No. 14, page 23.
Assay 6 from Mallet, Memoirs, Geol. Survey, Vol. XII, Part 2, page 80, No. 21