ON THE COMPOSITION OF A PERMO-CARBONIFEROUS

COAL IN NORTH CHINA

B K. ASADA (W&)(Society of Mining Engineers in Tsingtao)

In general, geologically, speaking, it has been noted that if the formationof coal took place during the Perino-Carboniferous period, its volatile mattetwill always be less than 30% when analized, 'and the contrary is usually thecase for coal created diiring the Tertiary and Jurassic, these hving more than40%.

It rarely occurs that the "Hsin Taj" coal, Permo.Carbonifer-ous. hasover 40% volatile matter. Another peculiar thing has been discoverd about thisdoal field and that is, although the thickness of the' stratum between the upperand lower coal seams is about 300 feet, still there is not mucb difference in thèanalytical quality of the coal.

If the following statements will serve to draw some attention, and leadto a more intensive researchinto such a volatile study, or bring about some im-portant survey concerning the caking power of coal, it will be greatly apprecia-ted by the writer.

The "Hsin Taj" coal field is situated in the center of theprovince ofShantung, North China, and its dimension is 25 square miles. The general strikeis northwest to southeast, with the dip N. or W. i5 to 25' which seems to betypical of this province, and the coal field is spread over a base of Ordovic:ianlimestone. A Crinoid limestone zone of about io or over ip feet in thicknessappears in the coal, which proves that this sedimentary series was evidentlycreated in the Permo.Carboniferous period, Paleozoic era.

The following three points might be of use in studying the coal seamsof this field.

(i) That the arenaceous limestone extends frçm 6o to xoo feet inthickness.

That as yet, no traces of eruptive rock has been found in survey-ing this field.

That very few faults exist in comparison with other coal fields ofthe Permo-Carboniferous, etc.

The Permo-Carboniferous has about ten seams of coal, and the followingfour are the main ones:

i8

The above mentioned partings are of carboniferous shale containing.pyrite.

It is a fine black coal of platy or prismatic structure and moderatelustre, perfectly clean and very solid, and it produced about 20% of dust in theprocess of mining. Well selected coal seemingly does not depreciate much inquality when expose to the weather.

Coal from this field has been stored for eight months and then testedand the result was that only about 1.8% of its volatile matter had decreasedThe results of technical analyses are tabulated in p. 187.

The tests, mentioned, were made within one, or three months afterthe samples were chosen, and they were stored in a wooden box.

It may be noted that the volatile matter slightly and gradually in-creases in the lower seams, while the upper ones have a copious amount offixed carbon, and correspondingly less ash, consequently the upper seanishave eitraordinary high calorific powers.

The result of "Asobu's" distillation test of the second seam named"Kao..Tan" is as follows (mean figures adopted from several tests.)

Whole water(Chemical water) 4.75% Tar 19.00%Gas 1375% Fixed C. 59.20%Ash 3.30%

The coke produced expanded well and caked substantially hard(Richter's caking power 2o.5), and by every test gave evidence of the fact thatit was rather difficult to take the coke out of the ovens.

"Fu-Shun" and "Miike" coals were tested as they resemble technically"Hsin-Tai" coal and the result of the test was that the contents of whole waterappear to be always Io% or double the quantity of that in "Hsin-Tai"coal.

When compared with other coal of the same geological age which

reseml:les it in its chemical qualities, such as "Chung-Hsing" coal, Shantungprovince, "Kaiping" coal, Chihli province, "Ching.hsing" coal, etc., it hasbeen found aftr testing that it never has over % of whole water.

Bulletin of the Geolo.'icoJ Socict of China 1oi. VII.

Thickness Parting

First seam "Pi.Tan" 3.5ft. (No parting)Second " "Kao-Tan" 6.5ft. (Three partings 3" to 9" thick)Third " "Tso-Miao" 8.8ft. (One parting 3" to 10" thick)Fourth" "Erh.Hsing" 7.9ft. (Two partings io" to is" thick)

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Bulletin of the Geological Society of China Vol. VII.

When "Hsiang.Tai' coal is mixed with from 20% to 50% of "Heijo"nivv anthracite, "Honan" anthracite, "Lieh-Shan" anthracite of Kiangsu pro-rince and 'Tzu-Chuan" anthracite respectively, the result is as follows.

Mixed coal and Whole

its percentage. Water Tar Gas Fixed C. Nature of coal AshHeijo návy anthracite 50% 6.00% 7.50% 7.00% 72.27% Caking 7.23°/

Lieh-Shan ,, 50% 4.00% 8.90% 9.60% 65.30% 12.20%

Tzu-Chuan ,, 50% 3.00% 9.50% 8.50% 64.40% 14.60%

All of the above mentioned coke produced was of good hardness, andsatisfactory in other respects.

Another test was that of mixing "Hsin-Tai" coal with "Chung-hsing","Ching.hsing", etc.

These latter kinds of coal having 2o% to 30% of volatile matter aresaid to have the strongest caking power among the bituminous coals of China.The result was that, when mixed with over 30% --thse coals the caking powerwas weak. A similar test was made by mixing with 20% to 30% of "eu Shun"and "Miike", both occur in the Tertiary, these coals having about the samequality in technicál analysis as "l-Isin-Tai" coal, and again the caking conditionwas not good.

A final test was of mixing with"Tzu-chuan" and 'Hsin.Tai" coal,half and half, and screened through a 3/S mesh (the work was done byhand in Tsngtau, during December and January.). Two ovens in the Chinese

native method were used, and their capacities were each 3 tons and tons. Theresult of the caking was successful, and an analysis of the coke produced isas follows:

Moist. 2.35% Vol. mat. 3.86% Fixed C. 81.63%

Ash xz.x6% Sulph, 2.09%

In conclusion, the following items may be worthy of being kept in mind'

(r) We cannot agree with Mr. Boulton's opinion, or that of other;,that coal which contains 20% to 30% of volatile matter has astrong caking power, or that 24/ is the strongest, or that, if thepercer tage is more or less than that, the power will be decresaein both cases.

(z) \Ve cannot agree with Mr. Bhead's opinion that coal which con.tains fixed carbon of 70% will cake the strongest, 6o% to 8o%also will give a fair. caking power, while more or less than thatpercentage will cause a decrease in caking power.

No. 2. Asada:Conposition of a PernjoCa.rbon. Coal in North China i8q

We cannot agree with the opinion that coal which has i% to 20%of volatile matter will have the highest calorific power, and thatalso more or less than this amount of volatile matter will decreasegradually the calorific power.

In classifying coal by the quantity of its volatile matter or byits fuel ratio, we do not agree with the opinion that coal contain-ing over 40% of volatile matter should be called lignite, and inthe fuel ratio, below one also lignite, and that from i to it shouldbe called bituminous coal, although this opinion is widely ap.proved of, and is the one accepted by Mr. Frazer of America andMr. Seyler of England and others. You will see that, althoughthe "Hsin-Tai" coal is classified as superbituminous, it has43.97% (the highest) of volatile matter and also. its fuel ratioiSLO

On one hand the chemical study of coal has been developed, buton the other hand, investigations have neglected considering therelation existing between geology and the analytical science olcoal, so that, now more attention is necessary to the study of thelatter.

6) It may also be interesting to ascertain what relations exist betweenthe geological age and the whole. water, . as the quantity of wholewater which is contained-in volatile matter, will have importantconnections with the quality of coal.