896

THE COLLIERY GUARDIAN.

May 3, 1918.

The words “ a detachable bulb-holder secured by a
spring clip is mounted in the glass ring ” at the end of
the paragraph shall be omitted.

Paragraph (4) shall read:—“ (4) The switch in the cover
is completely enclosed and is brought into action by
rotating the cover.”

The lamp as thus modified is illustrated in fig. 5.

The total weight of the lamp must not be more
than 5 lb. The strength of material and attachments
throughout the lamp must not be less than in the
samples submitted for the official tests on December 14,
1917;

<—=4—
Section - Elevation.

Fig. 6.

Joel-Fors Electric
Inspection Lamp,
Type 303 0.

Fig. 5.

Joel-Fors
Electric Lamp.
Type 403 M.

Mills’ Joel-Fors Electric Inspection Lamp, Type 303 C.

The following alterations shall be made in the
description of the Joel-Fors Electric Inspection Lamp,
Type 303 0*:—

The words “ or a battery-case of copper ” shall be
added after the word “ externally ” in paragraph (1).

The words “or copper” shall be added after the word
“ sheet iron ” in paragraph (3), and the following
sentence shall be added at the end of the paragraph :—
“ Provided that the cap shall overlap the case to an
extent of not less than fth inch.”

The last sentence of paragraph (4) shall read: —
“The bulb is protected by a stout optical lens and
holder provided with a vertical locking piece which fits
under the cover of the ca«e—provided that this vertical
locking piece is not less than J inch long.”

The lamp as thus modified is illustrated in fig. 6.

The total weight of the lamp must not be more' than
lb. The strength of material and attachments
throughout the lamp must not be less than in the
samples submitted for official tests on December 15,
1917.

* Safely Lamps Order of March 16, 1914.

THE AMERICAN COAL TRADE.

No improvement in conditions is reported from the
bituminous mines, and the Coal Age, April 6, states
that owing to car shortage hundreds of mines in the
bituminous districts of Pennsylvania were idle for days.
From West Virginia, Kentucky, Illinois and Indiana
come like reports. The results are a material reduction
in output. Not much improvement can be expected
under the present system of car distribution. The
trade is still a little uncertain, due to Government
commandeering and preferential shipment orders. The
zone system is also adding complexities.

No clear programme is observable, says a Boston
report, and buyers are in a quandary. Vessels are
difficult to obtain. Industries can be maintained on
present consumption, but where are the reserves ? The
price on watei’ shipments vid Hampton Roads is now
about 9’50 dols. per gross ton f .o.b. Boston or Providence.
In some cases rehandlers are asking as high as
11’20 dols., but this latter is the exception. When this
basis is compared with 3’05J dols. per net ton f.o.b.
mines for all-rail shipment plus 3 dols. or so freight,
the inequality is striking.

The shortage of high volatile grades, particularly for
illuminating and for by-product use, is causing real
alarm. Blast furnaces are using an enormously increased
tonnage, and attention is being called to quantities of
low sulphur coal used for fast train service. The fact
that anthracite also is going to be hard to get has a
bearing on the probable scarcity of gas coal. Lime
burners are also in straits for these grades, and unless
long flame coal is forthcoming it will go hard with a
lot of industries that are dependent upon them.

Coal is still short in Pennsylvania, chiefly owing to
inadequate supply of cars. Clean coal is at a premium.
The prices per gross ton f.o.b. cars at mines for line
shipment are as follow :—Broken, 5 90 dols.; egg, 4 80;
stove, 5’05 ; nut, 5T5 ; pea, 3’75 ; buckwheat, 315 ; rice’,
2’65 ; boiler, 2’45 ; barley, 215 dols.

Coal output in Pittsburg is repoited to be no better
than stationary, and a greater use of rivers for transport
is contemplated. There is considerable contracting
for coal being done for the twelvemonth beginning
April 1, but the major part of the business, or at least
a very large part, had been done before the recent
reaffirmation of prices, subject to Government price
ruling at time of delivery.

There is a moderate amount of free coal on the
market, but not equal to the demand in all cases. All
the intricacies of the zoning system have not been
ironed out yet, as applied to Pittsburg coal, which is
under less restriction than the coal in most zones. The
market remains quotable at 2’20 dols. for slack, 2’45 dols.
for mine-run and 2’70 dols. for screened, per net ton,
f.o.b. mine, Pittsburg district. Jobbers can charge
customers a brokerage in addition, up to 15 cents, when
regularly authorised.

A Connellsville report mentions that furnace coke is
only occasionally offered in the open market. The
market remains quotable at 6 dols. for furnace, 7 dols.
for foundry and 7’30 dols. for crushed, over lin. Sellers
of coke screenings, obtained from old dumps, have
raised their price from 5’50 dols. to 6 dols., having found
a good sale for this new-found material.

COKE OVEN MANAGERS* ASSOCIATION:
MIDLAND SECTION.

A meeting of the Midland section of the Coke Oven
Managers’ Association was held at Sheffield on Saturday,
April 27. The Chairman (Mr. J. W. Lee) presided,
and in opening the meeting said that the paper to be
read that day was by no means the first that the society
had had on the subject of benzol, and he thought it
would be by no means the last. The subject of the
rectification of benzol opened a wi-de field for discussion,
and they would never be able to put the whole available
information on the question before the members. There-
fore no apology was needed for the paper that afternoon,
which dealt with the rectification of benzol—a little side
line they had never had before the members in the form
of a paper for discussion.

Benzol Rectification.

Mr. T. D. Hamer, of the Middleton Colliery, read his
paper on “ Notes on Benzol Rectification.” (See p. 893.)

Discussion.

Mr. Wilson said that with regard to the washing in
the mixers, spraying would have to be very thorough
and a great deal of water would have to be used to make
the operation as efficient as agitation. There was always
trouble if the water was not of the best quality, because
the holes of the spray might get choked up and were
then difficult to deal with, being out of reach. He had
not found any trouble himself in that respect, though he
had had trouble from emulsification in washing. He had
had two types of agitator—the inverted cone type
and the one he was installing now. The latter was the
typhoon type, comprising a specially shaped plate
coupled up with a vortex breaker which had three plates
in line with the vortex and broke it up. The benzol
product then poured off and discharged down to the
mixer again. It was a most efficient type and the best
he knew of. The internal screw type was not nearly so

* effective. The new agitator had already reduced
the consumption of acid both in the light oil
washings and in the final washings for pure benzene.
With regard to cast iron unlined mixers, he had had
years of experience of one which was not lined, and it
was rather an extraordinary thing that while the sides
seemed to be practically intact, the cone-shaped bottom
was very badly attacked—not evenly all over the surface,
but in patches. He thought that was due to the lack of
uniformity in the metal itself. It was quite possible that
with a special make of cast iron they might get over
that difficulty. In this instance, however, it was affected
to such an extent that a new lined mixei* would have to
be obtained directly. It seemed as though there were
some alloys in cast iron that were more easily attacked
than the bulk of the iron. Unless they could get a
specially made metal for the purpose, he could not see
that there was any advantage in unlined mixers. He
had had trouble with the inverted 6ones, which were
liable to go if a little acid got inside. He referred to a
type of agitator which had been installed with a foot-
step. This footstep broke, but, as he was hard pressed
for pure product, they decided to go on with the work.
When they did get to it, it had broken right away. As
he had managed splendidly without the footstep, he now
took it off when putting in a new agitator.

Mr. Thorpe spoke of experience with lined mixers,
but said he did not do any water washing. His feeling
was that lined agitators should always be.put outside.
They were sure to leak, and if the plant was one that
had to work, come what might, there would be fumes of
benzol in the benzol house. Again, if the water supply
went off, disastrous results might happen. He knew of
many agitators which had been put out in the open, and
he did not see why they should not be away from the
benzol house, except for neatness and compactness. It
would certainly be conducive to keeping the material
cool; at any rate, the agitator should be away from the
crude benzol still. He would like to know something
about oils absorbing water, and what those oils were.
Finally, he spoke a word of warning about allowing too
much naphthalene to get into the distillate, as it had
the effect of making it too hot.

Mr. Smith said he had paid particular atten* ion to
the recovery of acid, and the results he had got in
Durham and elsewhere showed that the acid recovered
was 50 per cent, sulphurous acid. It also had the effect
of making a very white still, whereas he used to get a
grey one.

Mr. Chrisp, speaking with regard to the temperature
of the oil leaving the still, said that recently he had had
the temperature go up to 120 degs. Cent., whereas it
was previously 107 degs. to 108 degs. Up to a ceitain
amount he admitted it was all right to reduce the amount
of direct steam going to the still, but it should be
remembered that doing that lowered the carrying
capacity of the still. With regard to the percentage
of acid used in washing, he thought 5 per cent, was a
pretty general figure. The difficulty was that the plants
nearly all varied so much that it was impossible to get
standard results. He recently had a hint from a man
who produced benzol in very large quantities—he talked
in millions where the speaker would talk in thousands—
namely, to use a ring* round the top of the vortex to
reduce the amount of acid used. In his own case he
had reduced the amount of acid from 7 per cent, to 4 per
cent. With regard to Mr. Hamer’s suggestion of a
preliminary washing in D.O.V., he had found that
B.O.V. often avoided subsequent trouble.

Mr. Haigh (Barnsley Main) criticised the men being
required to test the distillation. At his colliery the men
had to look after the crude benzol plant and the rectifi-
cation plant, and do a few odd jobs besides. If they

had to test benzol he was afraid they would neglect
more important things. Practically all the testing was
done in tjie laboratory. The method Mr. Hamer
referred to for making pure products was a very compli-
cated one. He himself had been making pure products
which had satisfied even Dr. Spielman, who was not too
easily satisfied. He gave one preliminary washing in
sulphurous acid, without even the addition of nitric
acid, or anything else. He had a cast iron washer for
about 18 months, and the cone at the bottom was
slightly pitted; but if it lasted for six years, as
Mr. Thorpe’s had done, he would be quite satisfied to
renew the cone. It would not cost very much if the
sides were not touched. He agreed, too, with the
method of agitating the water, and found it quite satis-
factory, though he had had some trouble when they had
tried to agitate with water after caustic soda.

Mr. Price, suggested that only the bottom of the
washer should be lined. He knew of a plant which
had been working for eight or nine years, and though
the washer was not lined, it had not pitted.

Mr. Wilson said that the difficulty of adopting
Mr. Price’s suggestion was that it would not be possible
to get a good joint at the bottom. It would be impos-
sible to do that without raising the whole thing. One
could not get the cone free from the rest of the mixer.
Proceeding, he said that he had not found it necessary
to use nitric acid. The recovery of toluene from the
90’s was not very high—45 per cent, to 50 per cent. He
had had a great deal of trouble in connection with valves,
although he did not think his plant was any exception
to the general rule, or that he had been peculiarly
unfortunate in the matter of using cast iron gland cocks.
He used one with a gunmetal plug which could be
employed at the head of the valve, and had found it
very good indeed and easily repaired. He kept the
gland cock open all the time and only used it in case of
the other valve going.

Mr. Green enquired if the different results of
agitating arose from the difference in the experiences
with water and acid washing. In washing with water
after acid, it might be that the weaker acid was attacking
the iron. Where people were washing with D.O.V. as a
preliminary, it was best to use lead-lined washers. He
knew where silicon had been satisfactorily used in the
washing as a preventive against corrosion.

The Chairman said there were many points of
interest to all of them. With regard to cast iron
washers, he had used them for considerably over six
years, and they were as good as the day they were put
in. There was no sign of pitting at the bottom or the
sides. He did not water-wash, and the cases of water
washing mentioned in the paper would be fatal in his
case. Mr. Hamer said he washed for an hour and
allowed the wash.to stand for an hour. His (the
speaker’s) experience of that was that, if the wash were
allowed to stand before running off the acid after
washing, they would have to take the bottom off to get
it out. It settled so hard after 20 minutes that it would
be impossible to continue. He knew of othei* plants,
but had never heard the time of settling given so high
as by Mr. Hamer. He mentioned an experience he had
with a German chemist who came to his plant some
years ago, and tried the method of letting the wash
remain standing fox* half an hour. At the end of that
time it had to be dug out. He went to another plant
and did the same thing. When he (Mr. Lee) was asked
his < pinion about the man, he suggested that the people
who sent him out should have him on their own plant,
and they would soon find out what be was like. They
removed him to Germany after two experiences of
removing the bottom of the washer. With regard to
the actual washing, it was unnecessary to go to the
expense of washing with caustic soda, sodium carbonate
being quite sufficient. All that was needed was
neutralisation. He had used it for a considerable time
and found it quite as good and much cheaper. It was
merely by accident that he found that out. They had
a large number of electric lamps in use in the colliery,
the accumulators of which were charged with caustic
potash. With these lamps they received from the
German makers a guarantee on consideration that they
used caustic potash. That was because the Germans
had a good Supply of caustic potash. When the
supply of potash became scarce he staked his reputation
as a chemist by saying that, if they reverted to caustic
soda, the efficiency of the lamps would be as good and
no damage would be done to the cells. They were now
using the caustic soda for all these lamps. After some
time the cells were washed out and the result was a
fairly practical sodium carbonate, which came back to
his plant for neutralisation purposes. The amount
saved by this practice was about £120 per annum—not
very much, but worth while. Proceeding, he said that
the mixer agitator was as good to-day as ever it was.
He had found solvent naphtha washing very hot. In
one instance he lost 2,000 gallons of solvent naphtha.
The man in charge ran his caustic soda into the washer
very fast. The pan became full and, fortunately for
him, he came down the ladder very quickly. The
washer which was very hot had added to it the chemical
heat of the soda and the sulphuric acid, and the result
was the whole lot boiled over. After that they had had
no difficulty from the beat of the washing. By practice
they had found that two washings were better than one.
The separating of the water was a very important point.
It should stand in the washer an hour or two—the
longer the better, but the water should be run off very
carefully. In these matters each man could only spoak
of his own plant. He himself never used more than
considerably under 4 per cent, of acid, and sometimes
even as low as 3 per cent., and he was still able to
supply Government requirements. He thought their
success was due to the fact that they saturated the
water well and had a good type of washer of 4,000
gallons capacity. With regard to the recovery of
acids they were not doing it now, as they were making
only concentrated liquor. Up to some six years ago
they recovered acid and boiled it out in a cast iron pot
unlined.

Replying to the discussion, Mr. Hamer said with
regard to Mr. Wilson not agreeing with agitation for