AN IMPROVED COMPOSITION TO BE USED IN THE MANUFAC- TURE OF ARTIFICIAL FUEL.
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 16th April 1878. A communi-
cation from abroad by Charles Francois Xavier Nory, of Paris, France.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Mid-
dlesex, Patent Agent. "AN IMPROVED COMPOSITION TO BE USED IN THE MANUFAC-
TURE OF ARTIFICIAL FUEL. [A communication from abroad by Charles Francois
Xavier Nory, of Paris, France.]
:
The Invention relates to the production and application of a new product for
agglomerating small coal or other combustible in the manufacture of artificial
fuel.
The agglomeration of small coal with coal-tar pitch has the objection of increasing
the amount of smoke produced, and in the case of coal of a smoky nature such
mixture is unfit for use. Coal-tar pitch, which is the agglomerating agent most
commonly employed, has also the further objection that it fails to sufficiently agglo-
merate bituminous coal when used in the same proportions as for non-bituminous
coal. For example, Cardiff coal may be agglomerated with from 6 to 8 per cent. of
pitch, but Newcastle coal requires from 10 to 25 per cent. of pitch, the degree of
compression being the same in both cases. With such an addition of pitch, how-
ever, the unpleasant odour and sinoke evolved during the combustion of the coal
would be insupportable. For this reason only those varieties of coal which are
relatively non-bituminous could be advantageously agglomerated hitherto. The
same objection applies to the use of coal tar instead of its pitch.
This Invention relates to the employment for agglomerating bituminous and
seini-bituminous coal of a compound or sort of double soap consisting for the most
part of native asphaltum or bitumen, whereby the foregoing objections to the-use of
coal-tar pitch are obviated..
Asphaltum alone cannot be advantageously employed as an agglomerating agent;
being a substance which melts at too high a temperature, and moreover its agglo-
merating power even at a higher temperature is insufficient, the agglomerated pro-
ducts being friable and possessing no cohesion or solidity when cooled. It has been
found; however, by experiment that asphaltum is capable of being dissolved in a

page_text: solution of soap, and of being partially held in suspension therein. With a certain
quantity of water which also enters into combination a compound is obtained of
the consistency of coal tar (at 100° C.), but which has none of the disadvantages of
the latter. This aqueous tar or soap emits no disagreeable odour, and burns when
mixed with small coal without producing any additional smoke, this advantageous
quality being apparently due to the small quantity of alkali which it contains,
which does not however cause any objectionable increase of ashes, as it is not neces-
sary to employ more than from 5 to 7 kilogrammes to every ton of coal. This
preliminary explanation given, I will proceed to describe the method of preparing
the composition which the Inventor calls a 'soap cement;" all soaps having a
base of potash or soda are suitable for use with native asphaltum or bitumens, the
cheaper kinds being preferred.
"
A cheaper primary soap may be made of common resin, arcanson, or colophany,
or of saponifiable oils of coal tar or petroleum, such as creosote, phenal, and others.
I will describe the manufacture of the soap cement by combining either natural
Seyssel asphalte or Trinidad asphalte with a resin soap, as it is the most complex
example.
For one ton (1000 kilos.) of small coal, 5 or 6 kilos. of dry carbonate of soda are
dissolved in from 20 to 30 kilos. of water, to which is added 10 to 12 kilos. of
common brown resin. The whole is then boiled in an iron vessel having a capacity
of from 300 to 400 litres, and stirred from the time ebullition commences until the
whole of the resin is dissolved in the alkali.
Rosin having, as is well known, the proerty of expelling the carbonic acid from
carbonates, it is unnecessary to employ caustic alkalies; but if phenal or creosote
be used instead of resin it would be necessary to first decarbonate the alkali, which
may be done without much expense. After boiling for a few minutes a resin soap
is obtained, and a double soap is then formed by adding from 50 to 60 kilos. of
asphaltum in small lumps, or preferably in powder, and also from 30 to 35 kilo-
grammes of water, and again boiled and continually stirred. When the asphalte
begins to be dissolved from 10 to 20 kilos. more water are added, the boiling and
stirring being still kept up, and after about 20 minutes boiling the water will for
the most part be combined with the other substances, whereupon the soap cement
is obtained fit for use, and forms a solid mass when cooled. The compound is used
by pouring it while hot upon the small coal to be agglomerated, and then kneading
the whole together and moulding as in ordinary. It is however of advantage, in
order to ensure a thorough mixture suitable for compressing, to commence by heating
the coal to a temperature of from 90° to 100° C., to place it in the mixing or
kneading machine, to run in upon it the "soap cement" maintained at a temperature
of 100° to 110° C. to ensure the necessary degree of fluidity. The mixture should
not be allowed to cool before being placed in the press moulds.
The proportions of the different materials vary slightly with the kind of coal and
size of the agglomerated blocks.
As before mentioned the saponifiable heavy oils of tar may be substituted for
the resin. These oils, such as creosote, phenal, or carbolic acid, cresylic acid, trichlo-
rophenic acid, and others, are dissolved in the soda or potash with which they form
a soap by saturating the alkali; the asphalte is then added, and after boiling a few
minutes a soap cement is obtained.
For example, to 5 kilos. of soda dissolved in 40 to 50 kilos. of water are added
10 to 12 kilos. of oil, and the whole heated and boiled until complete saponification,
from 40 to 50 kilos. of water are then added, and from 50 to 60 kilos. of asphalte,
and the whole is again boiled until the mass attains the desired consistency, and
the soap cement is produced.
The above proportions of the several ingredients vary according to the nature of
the oils or mixtures, and of the coal and the size of the blocks to be produced.
If it be desired to substitute a soap having a base of lime, magnesia, alumina,
oxide of iron, or other earthy base, it is simply necessary to add to the soap cement
made with potash or soda one of these earthy bases, or one of their salts, whereby

page_text: the former base will be eliminated and the one added substituted therefore; this
addition of lime, magnesia, or alumina, or a salt of these bases, however, presents no
advantage except in the case of bituminous and pyritic coal, which are more difficult
to agglomerate, and whose combustion is improved by the presence of an alkali
or solid oxide. In any case the presence of a soluable or insoluable alkali in a
pyritic agglomerate would have the effect of preventing the instantaneous com-
bustion of the fuel if this combustion is due to the action of the air on the pyrite.
Mention has been made of purified asphalte, but it will be understood that crude
asphalte in its natural state may be used, provided it does not contain too large a
proportion of foreign matters, which would cause an excessive increase in the
quantity of ashes. In this case, however, the proportions are varied; for example,
Trinidad bitumen or asphalte contains in its natural state about 30 per cent. of
earthy matters, and if it be used in this condition without being purified, 8 per cent.
of small coal should be used instead of from 5 to 6 per cent., as before.
Other matters may also be added to the soap cement, such as the more or less
solid residues of the manufacture of shale, boghead, or rock oils, and kinds of artificial
asphaltes very different from coal tar and pitch, and which like natural asphalte
may be formed into a double soap by then mixing with any alkaline soap.
The product known in commerce under the name of vulcan oil may also form an
ingredient of the first or alkaline soap as well as of the second or double soap
when accompanied with a certain proportion of asphalte.
Lastly, there are some qualities of non-bituminous coal which combine better with
pitch and tar than the bituminous kinds, and the above agglomerating agent may
be employed with these as well as with mixtures of different kinds of coal with the
addition of more or less pitch or tar.