February 22, 1918.

THE COLLIERY GUARDIAN.

385

demand is current for industrial fuels, with the
exception, perhaps, of fine slacks. A slight decrease
m the demand for Yorkshire house coal is accountable
for better deliveries. All kinds of manufacturing
fuel are in urgent demand. Stocks in South Wales
are still excessive, but generally speaking the pits
are. working with more regularity, although some
stoppages are reported. The market is stagnant. In
Scotland the improved tone continues.

The anthracite coal market is rather weak, as
supplies are in excess of demand. Buyers can obtain
prompt deliveries of all qualities. The exports of
patent fuel have increased.

The freight market is firm, and Scandinavian
business has a stronger tone. In Newcastle the
coastwise trade is quiet and unchanged. Business
in South Wales has been subject to questions con-
cerning the new scheme of maximum freights to
the French ports.

Coal, coke and manufactured fuel exports in
January were 2,887,573 tons, valued at £4,130,931,
compared with 3,488,494 tons, valued at £4,588,227,
a year ago.

Mr. W. Greaves will read a paper on “ Notes on
the Manufacture of Concentrated Liquor and Benzol”
at a meeting of the Coke Oven Managers’ Associa-
tion (Midland section), to-morrow (Saturday), com-
mencing at 3.30 p.m.

The Prince of Wales continued his tour in South
Wales on Thursday, and, among other places, visited
Cardiff Coal and Shipping Exchange, where he was
enrolled a member, and subsequently left for Ebbw
Vale, where he inspected the great steel works of
which Sir C. Allen is chairman. Afterwards, in
the Victoria coal mine, he watched the miners, and
then handled a small pick and cut away a piece of
steam coal, which he took away with him as a
memento.

Capt. D< Bowen will read a paper on “ The Effect
of Taxation on the Development of Mineral Estates,”
at a meeting of the Surveyors’ Institution, 12, Great
George Street, Westminster, on Monday, February 25.

An important paper was read on
A Mew Monday night, before the Institution

British Oil of Petroleum Technologists, upon
Industry. the prospects of founding in this
country a new industry for the
purpose of increasing our supplies of fuel oil,’ includ-
ing in this term petrol.

The authors of this paper, an abstract of which
appears in another column, state that at the begin-
ning of 1916 the Government appointed two
committees, one to investigate the problem of
desulphurisation of Kimmeridge shale, and the
other to consider the methods of distilling oil from
various organic products found in this country. It is the
latte'r question which is now discussed. The actual
possible sources of oil to be obtained by distilling
are six in number. These, however, so far as a
practicable new industry is concerned, are reducible
to cannel coals and torbanites, including amongst
the latter the black band ironstones which in some
respects resemble them.

Cannel coal, as is well known, possesses a large
number of spores which are believed to yield on
distillation waxes and resinous compounds. The
torbanites, which look very much like cannel to the
eye, are really of a different nature. They are not
by any means peculiar to the Bathgate district from
which they derive their name, although the typical
Torbanehill mineral is richer than that found in
some other coal fields. Torbanite consists of a coal
matrix in which are embedded certain ovoid globules
known as kerogen, the exact nature of which has
been a source of much discussion. The net result of
much research seems to have been to prove that
kerogen globules indicate a kind of passage between
coal and oil. The difference in quality shown by
various torbanites is caused essentially by the
amount of degradation the kerogen globules have
undergone, and the quality of the oil yielded by dis-
tillation varies according to the particular stage to
which the process of degradation has advanced. Now
most cannels contain a certain proportion of kerogen
globules, and all torbanites contain more or less uncar-
bonised vegetable matter and spores. So that it has
come about that many English torbanites are known
as cannels. It is difficult, therefore, to draw any
hard and fast line between them. The important
thing to recognise is that it is the kerogen globules

which really count, and it is these bodies which yield
on distillation oils of the paraffin and olefine series,
in an abundance which is determined by the freshness
of the material, the most degenerate types yielding
chiefly the heavy paraffin waxes. As the kerogen
globules in any sample can be easily recognised by
the aid of the microscope, both the quantity and
quality of the oil which is obtainable can thus be
estimated approximately by this means. The black-
band ironstones, again, are an intimate mixture of
iron oxide with coaly material, which is generally
kerogenous, and capable of yielding oil on distilla-
tion. It is satisfactory to know that these ironstones
can be distilled and the oil recovered without
detracting from their value as iron ore, since fixed
carbon is left behind in intimate association with the
iron oxide, and in an ideal condition for the blast
furnace.

The authors point out that this consideration is
important from more than one standpoint. Not only
is the ordinary method hitherto practised of treating
blackband ironstone wasteful and costly, but, what
is of even greater consequence, there are many
composite seams of coal, ironstone and torbanitic
cannel, which, although too thin to work for iron
ore alone, would be capable of being mined with
profit for purposes of preliminary treatment for oil
recovery and subsequent use as metallurgical ore.
A new industry can, in the authors’ opinion, be
formed for the purpose of distilling various deposits
of this class by some suitable low temperature
process.

The authors point out that it will probably be
advisable to adjust the temperature of carbonisation
to the quality of the material. One of the diffi-
culties encountered in low temperature processes has
been the deficient yield of ammonium sulphate,
except at a temperature which causes cracking of
most of the light oils. Ammonium sulphate, a
valuable product of the Scotch shale oil industry,
requires a fairly high temperature for its production;
but torbanite yields, in any case, only a small, pro-
portion of this substance, and but little would,
therefore, be sacrificed by distilling it at a low
temperature. Cannels, on the other hand, which
yield but little light oil, could be distilled at a higher
temperature with a view to maximum ammonium
sulphate recovery. Thus, a suitable classification of
materials, where this is possible, would enable the
most economical use to be made of them. Where
the material is too intimately mixed for grading
according to quality, it would be necessary to arrive
at a compromise, in which local conditions and other
economic considerations would play their part.

As regards the yield of oil to be anticipated, these
are computed to be as follow :—

Water-free oil
per ton.

Bastard cannels ..... 20-25

Torbanite cannels   40-50

The petrol yield from this oil would vary between
4 and 10 per cent., and an average yield of
ammonium sulphate might, in the author’s opinion,
be estimated at 30 to 401b. per ton of mineral
retorted.

In dealing with the economic aspect of the
question, the authors point to the great prosperity to
which the Scottish Shale Oil Companies have, after
some vicissitudes, arrived, and while the advantage
will probably remain with them in most cases, they
have one great difficulty—viz., the disposal of refuse
—which would be avoided in the proposed new
industry, because the product of distillation of
cannels would be capable of utilisation either in the
form of briquettes or in gas producers.

The position which the coking and
Modern by-product industry of this country
Coking	has assumed in consequence of the

Practice.	war is alone enough to justify the

publication of all available informa-
tion respecting it. It is a subject, moreover, about
which there is much to be said concerning the
respective merits of the various methods and appli-
ances in vogue in this country. It is, therefore,
gratifying to find that a second edition has been
published of the work on “ Modern Coking Practice,”
by Mr. J. E. Christopher, including the “ Analysis
of Material and Products,” by Mr. T. H. Byrom.*

* Modern Coking Practice, by J. E. Christopher and T. H.
Byrom, Vol. I., “Baw Materials and Coke”; Vol. II.,
“By-products.” London: Crosby Lockwood & Son, 1917.
Price, 7s. 6d. net, each vol.

The work now appears in two volumes, the first
dealing with plant and raw materials, the second
with by-products. The original text has been con-
siderably amplified and the illustrations for the most
part have been re-drawn.

The interdependence of the coke and the metaL
lurgical industries is graphically shown in a diagram
giving the output of pig iron and coke of Great Britain,
United States and Germany since the beginning of the
present century. It is significant that Germany
stood first in respect to the proportion of coke made
in “recovery” ovens. The backward state both of
this country and the United States in regard to this
matter has often been a matter of comment in these
columns ; but the war has changed many things, and
there has been so rapid a transition from beehive
to by-product ovens all over these two last named
countries that it is not improbable that Germany will
find herself, after the war, displaced from the position
to which she had attained prior to 1914.

A chapter useful to collieries contemplating the
installation of coking plant is that dealing with
impurities in coal and their influence upon coking
properties. These are considered mainly from their
effect upon the plant. Thus pyrites is objectionable
owing to its oxidation to sulphuric acid, which has a
corrosive effect upon any iron or steel with which it
comes into contact. But this, as the author shows,
is not the whole evil, since a large proportion of the
sulphur, reaching perhaps 72 per cent, or more,
remains in the coke. Then again there is the influ-
ence of salty coals as a factor in the corrosion of coke
oven walls. Such considerations as these must all
be taken into account in estimating the suitability of
a coal for coke‘making purposes. The improvements
that can be effected *by washing are also discussed,
and this portion of the subject is followed by useful
chapters, we presume by Mr. Byrom, upon the
sampling and valuation of coal and coke, a matter
which is perhaps somewhat beyond the compre-
hension of the layman, although it is distinctly
useful that he should acquaint himself with some of
the technicalities of analytical processes. We cannot
in so limited a space follow the author through the
history of coke manufacture in this country and the
development of coke oven design. There is much
here to interest and instruct, and the illustrations of
recent types of coke ovens and mechanical appliances
are particularly well drawn. The volume concludes
with a chapter on the chemical and physical examina-
tion of coke, which is short, but enough to satisfy
requirements in this country, where complete analyses
are seldom demanded.

The second volume, dealing with by-products, will
perhaps, in these days, appeal even more strongly to
the colliery manager than the consideration of plant
and appliances. It is pointed out that by-product
recovery depends upon two main principles, viz.,
temperature regulation with respect to condensation
of vapours, and intimate contact with the solvents used
for their removal. Thus we are concerned in the first
place with the cooling and condensing plant and gas
exhausters. It is interesting to find here a detailed
account of the “ direct ” processes of ammonia
recovery. Brunck’s process, invented in 1903, at first
failed owing to the ineffective removal of tar from
the hot gas, causing the formation of dirty sulphate.
For the removal of this tar several methods are
available, such as the Otto process, in which a
specially designed spray extractor is employed, the
centrifugal process of Simon-Carves, the Simplex
method, the Koppers’ system, the Coppee process and
its modifications. In connection with this part of the
subject the author refers to the recently advocated
methods of utilising the sulphur in the coal for the
production of the sulphuric acid required to neutralise
the ammonia. Both the Burkheiser and Feld
processes are outlined, and a simple summary is
given of the rather complex chemical reactions
involved, while brief reference is also made to the
more recent method suggested by Prof. Cobb, of
Leeds University, in which .there is a complete
cycle of reactions enabling ammonium sulphate to be
formed continuously at the expense of the sulphur in
the coal.

We can only briefly refer to the treatment of
benzol recovery, the principles of which are here clearly
and simply set out, and the necessary plant described.
Attention is given not only to the crude product but
also its rectification, both by intermittent and con-
tinuous methods. Throughout these volumes the