IMPROVEMENTS IN TREATING IRON ORES, AND OTHER MINERAL SUBSTANCES, FOR EXTRACTING SULPHUR AND PHOSPHORUS AND FOR THE SUBSEQUENT CONVERSION THE PHOSPHORUS INTO PHOSPHATES " OF PROAL SP
Year: 1883

page_text: LETTERS PATENT to Alfred Adair and William Thomlinson both of Seaton
Carew in the County of Durham for an Invention of "IMPROVEMENTS IN
TREATING IRON ORES, AND OTHER MINERAL SUBSTANCES, FOR EXTRACTING
SULPHUR AND PHOSPHORUS AND FOR THE SUBSEQUENT CONVERSION
THE PHOSPHORUS INTO PHOSPHATES "
OF
PROVISIONAL SPECIFICATION left by the said Alfred Adair and William
Thomlinson at the Office of the Commissioners of Patents on the 10th February
1883.
ALFRED ADAIR and WILLIAM THOMLINSON both of Seaton Carew in the
County of Durham "IMPROVEMENTS IN TREATING IRON ORES AND OTHER MINERAL
SUBSTANCES, FOR EXTRACTING SULPHUR AND PHOSPHORUS AND FOR THE SUB-
SEQUENT CONVERSION OF THE PHOSPHORUS INTO PHOSPHATES
وو
Our invention relates to the treatment of iron ores, stones, minerals and
materials resulting from the smelting or manufacture of iron as for instance slag,
tap or mill cinders, by which means the iron ores, stones, or cinders are purified
from such injurious ingredients as sulphur and phosphorus and the phosphorus so
recovered is subsequently converted into phosphates.
In carrying out our invention we first reduce the materials to be operated upon
to a finely divided state, which may be accomplished either by passing them
through rolls, squeezers, stamps, crushers or any similar or suitably arranged
apparatus, and separate the fine from the coarse particles by means of sieves or their
equivalents, or by the process of trituration and separation by the action of water.
In some cases the materials under treatment may be advantageously submitted
to a process of oxidation, whether by calcining, weathering, steaming or otherwise
oxidating them, and this operation inay take place before or after or both before
and after the materials have been reduced to the finely divided state before
mentioned.
The materials having been thus pulverized and where necessary oxidated as
well, are then conveyed to one or more suitable chambers or receptacles and

page_text: treated with hydrates of soda and potash, separately or in combination, or with
carbonates of soda and potash separately or in combination, or with the oxides,
hydrates, carbonates, clorides, nitrates, sulphates, acetates or other salts of metals
such as Potassium, sodium, ammonium, magnesium, calcium, strontium, barium and
others, either singly or in suitable combination, or with sulphuric, bydrochloric,
nitric and acetic acids.
The materials under treatment having been in this way thoroughly impregnated
with or without the aid of water, with one or more of the before mentioned
inaterials are then subjected to the action of heat of a suitable temperature in
vessels or any suitable contrivances which may be open or closed.
The materials are then lixiviated or washed with water, steam or acid, by
means of centrifugals, jiggers, mixing pans or their equivalents, from which the
solution thus obtained is run off into settling ponds or other receptacles and the
phosphorus is precipitated with milk of lime or other chemical compounds of
calcium, magnesium, barium, ammonia and other metallic substances.
The precipitated phosphates are separated from the liquids by decantation or
otherwise and are then washed, dried, and rendered fit for commercial purposes;
the salts or alkaline compounds contained in the resulting solutions are recovered
-by evaporation, crystallization or otherwise and when practicable are used over
again for the same process.
The solid residues of the materials treated, when such materials contain iron, as
for instance iron ores, stones, tap and mill cinders, are 'sintered' or formed by
the action of heat into lumps of pieces, or are mixed with a suitable proportion of
lime or other cementing material and water or other liquid, and formed into lumps
or pieces which are dried in any convenient way, these residue materials being
thus rendered fit for the process of extracting the iron contained therein

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Adair and William Thomlinson in the Great Seal Patent Office
on the 10th August 1883.
ALFRED ADAIR and WILLIAM THOMLINSON both of Seaton Carew in the
County of Durham "IMPROVEMENTS IN TREATING IRON ORES AND OTHER MINERAL
SUBSTANCES FOR EXTRACTING SULPHUR AND PHOSPHOROUS AND FOR THE SUB-
SEQUENT CONVERSION OF THE PHOSPHOROUS INTO PHOSPHATES
"
Our Invention relates to the treatment of iron ores, stones, minerals, and
materials resulting from the smelting or manufacture of iron in its various
modifications of cast iron, wrought iron, or steel, as for instance, tap, or mill cinder,
or slags known as basic slags, or similar materials, by which treatment as herein-
after described the iron ore, stones, tap and mill cinders, and similar materials,
are purified from. such injurious ingredients as sulphur and phosphorus, and the
phosphorus so recovered from these materials or from basic slags is subsequently
converted into useful phosphates, such as the phosphates of the alkalies and
alkaline earths. In carrying out our Invention we reduce the materials to be
operated upon to a finely divided state, or, if this is only partially. effected, the
fine particles must be separated from the coarse particles: the mechanical
operation, or operations, by which this is accomplished, forms no part of our
Invention, whether the finely divided state is produced by means of rolls, squeezers,
stamps, crushers, or other similar or suitably arranged apparatus, and the
separation of the fine particles from the coarse particles is effected by means of
sieves, or their equivalents, or by trituration and separation by the action of
water.
.
In some cases, the materials under treatment may be advantageously submitted
to a process of calcination; this will be especially the case when phosphoric acid
exists in combination with iron protoxide, and this operation may take place
before or after; or both before and after, the materials have been reduced to the
finely divided state before mentioned. When the materials under treatment arê
tap or mill cinders and similar substances, after the operation of pulverization
(and where desirable of calcination also) these materials are placed in suitable iron
pans, or receptacles, and are mixed with a solution of soda in the proportion of
about three equivalents of soda to each equivalent of phosphoric acid contained in
the material under treatment. The mixture so formed is then heated in the iron
pans, or receptacles of any suitable construction, until the phosphoric acid goes
into solution.
3
The solution obtained in this manner is then decanted or filtered off from the
insoluble residue, which insoluble residue is then repeatedly washed to free it from,
adhering soda.
When the filtrate contains much silica, Alumina, iron, or manganese, these
substances may be precipitated by drawing or forcing air and carbonic acid or
either through the liquid, which is again decanted or filtered off from the
precipitated materials and run off into suitable receptacles.
Milk of lime is then added to the 'solution, and the precipitated phosphate of
lime is filtered off and undergoes a process of washing to free it from adhering
soda, or when the solution contains much carbonate of soda, we prefer to separate
this by crystallization and subsequently to precipitate the phosphoric acid with
ime.
In carrying out the above process, the materials under treatment, instead of
being mixed with a solution of soda as already described, may be mixed with &¨
:

page_text: solution of potash, the proportions used and the process employed being precisely
the same as required for soda, a resulting product from the use of potash being
phosphate of potash.
By a modification of the process, the materials may be mixed with a solution of
ammonia in about the same proportion as, but instead of, soda or potash, in which
case the mixture must be heated in a closed vessel or retort until decomposition is
effected. The beat may be applied to the outside of the vessel, or retort, by means
of a fire, but we prefer to place, within the closed vessel, or retort, a coil or system
of pipes provided with outlets and inlets to pass steam through, the heat so
applied being sufficient for the purpose and under better control. As soon as
decomposition is effected, the mixture is forced or ejected from the closed vessel or
decomposing apparatus into a filter press; this is effected by opening a passage
in the lower part of the decomposing apparatus, the contents being discharged by
the aid of the internal pressure which has been generated by their exposure to
heat in a confined. vessel: to avoid loss of ammonia, and to thoroughly cleanse the
decomposing apparatus, a jet of steam or water may be discharged into it which
will pass thence through to the filter press and wash the insoluble contents; the
filtrate is conveyed into known distilling apparatus, where it is distilled alone or
treated with lime for the recovery of the ammonia by well known methods.
Instead of using the caustic alkalies, we prefer in some cases to employ their
carbonates, more especially in treating slag obtained in the basic process of steel
making, or in treating phosphatic iron ores and minerals in which the phosphorus
exists as phosphate of lime and in all cases where free lime is present in the
materials under treatment, excess of carbonates should be used. In treating the
materials with carbonates of soda and potash, the same process is used as in
treating them with solutions of soda and potash; and in treating the materials
with carbonates of ammonia, the same process is used as in treating them with a
solution of ammonia; but the phosphoric acid will generally be found to go into
solution at a much lower temperature than is required, in using the solutions of
soda, potash, or ammonia
The solid insoluble residue obtained from any of the above described processes
for the treatment of iron ores, stones, tap or mill-cinders, and similar substances,
are thus purified from sulphur and phosphorus and are sintered or formed into
lumps or pieces by the action of heat, or are mixed with a suitable proportion of
lime or clay to form them into lumps which can then be applied to the manufacture
of iron or steel.
When the iron ores, stones, or cinders contain a large amount of silica, we
sometimes prefer to mix them with caustic lime by calcining them together with
limestone and then submit them to one or other of the above described processes,
In such cases, the heat developed by mixing the materials to be operated upon
with the solutions of the alkaline salts after they have been mixed with lime, is
sometimes sufficient to cause the phosphorus to go into solution without applying
additional heat
Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is, or may be used, or carried into
effect, we would observe in conclusion that what we consider to be novel and original
and therefore claim as the Invention secured to us by the hereinbefore in part
recited Letters Patent is :-
First. The treatment of tap or mill cinders, and similar substances containing
sulphur and phosphorus, with solutions of soda and potash, for the purpose of
purifying them from sulphur and phosphorus, and for converting the phosphorus
into useful phosphates, substantially as before described.
Second. The treatment of iron ores, stones, precipitated iron phosphate or tap or
mill cinders, and similar substances containing sulphur and phosphorus, with a
solution of ammonia, for the purpose of purifying them from sulphur and
phosphorus, and for converting the phosphorus into useful phosphates, substantially
as before described.

page_text: Third. The treatment of phosphatic slags as obtained in the basic process of
steel making, and of phosphatic iron ores or minerals (especially those in which the
phosphorus exists as phosphate of lime), with carbonates of soda, potash, or
ammonia, for the purpose of converting the phosphorus into useful phosphates,
substantially as before described.
Fourth. The treatment of phosphatic iron ores, stones, tap or mill cinders and
similar substances with lime, when these materials contain much silica, before
subjecting them to any of the above described processes.
In witness whereof we the said Alfred Adair and William Thomlinson have to
this our Specification set our hands and seals this thirtieth day of July One
thousand eight hundred and eighty three
ALFRED ADAIR
(L.S.)
WILLIAM THOMLINSON (LS)