IMPROVEMENTS IN THE TREATMENT OF SLAG AND PHOSPHATES
Year: 1884

page_text: .
I ADOLPH FRANK, doctor of philosophy, of 80 Leibnitzstrasse Charlottenburg,
near Berlin, Prussia German Empire do hereby declare the nature of said invention
for "IMPROVEMENTS IN THE TREATMENT OF SLAG AND PHOSPHATES to be as
follows:-
"3
This process is for cleansing and dissolving slag of all kinds especially the slag
from iron smelting furnaces and basic Bessemer slag but also other naturally found
or artificially produced phosphates and depends mainly on the application of
chloride of magnesium.
The molten liquid slag, for instance is run into a sufficiently concentrated
solution of chloride of magnesium, generally of a specific gravity of about 106 and
is stirred to the consistency of a powdery mass. The sulphides and sulphurous
parts contained in the slag will thereby be eliminated while hydrogen sulphuret is
evolved; also the free lime contained in the basic slag combining with chloride of
magnesium forms magnesia and chloride of calcium and thus indirectly produces a
concentration and greater solubility of the phosphates contained in the slag, as for
each 28 parts of oxide of lime 20 parts of oxide of magnesium are required which
latter may partly be removed by mixture with water and settling. The powdery
slag with the still remaining or to be added chloride of magnesium is besides
heated by oxidizing flame and thus a partly higher oxidation is effected of the
lower oxides of iron (Fe O) and the like which are noxious for direct application as
manure,
Instead of letting the molten liquid slag run directly into the chloride of
magnesium solution the already cooled finely divided slag may of course also be
treated with chloride of magnesium solution under application of heat and by high
steam pressure in order to decompose the sulphur compounds contained in the slag.
and to bring the free lime into solution by conversion into chloride of calcium.
The same method is also applicable for the cleansing and concentrating of
naturally found or artificially produced phosphates, especially such as do not
contain lime combined with phosphoric acid and which have to be rendered
caustic by burning for instance phosphate containing marl. Before the treatment
with chloride of magnesium there must hence with such phosphates be a burning
in order to drive out the carbon dioxide.
The slag or phosphates thus treated may be applied directly for manure purposes
or may in the known way be further treated for obtaining or concentrating the
phosphates.

page_text: The following mode for extracting and utilizing these phosphates is however
preferred:
The phosphate containing material is so treated with a chloride of magnesium
solution and an addition of chloride of ammonia and muriatic acid in about the
proportion of one equivalent of tribasic phosphate of lime for about one of muriatic
acid, and about two of chloride of magnesium and one of chloride of ammonium.
The muriatic acid dissolves the phosphate of lime and transfers it again to the
chloride of magnesium and the ammoniacal salt in double decomposition in such
manner that chloride of calcium and ammonia-magnesia phosphate are formed in
the solution. The latter is precipitated after the aforesaid conversions by
neutralizing the free acid by means of carbonate of lime or magnesia and final
addition of caustic alkalies or caustic alkaline earths.
Instead of the chloride of magnesium and chloride of ammonium I may use in
about the aforesaid proportions sulphate of magnesium and sulphate of ammonium
together with free muriatic acid, that is to say, for one equivalent of tribasic
phosphate of lime two equivalents of sulphate of magnesium and one equivalent
of sulphate of ammonium together with somewhat more than one equivalent of
muriatic acid. The said sulphates or salts are either added directly, or in such
manner that they are added partly as chlor-compounds to the bases in question by
simultaneous addition of free sulphuric acid in a quantity equivalent to one of
these parts, which sulphuric acid again can be replaced by an equivalent amount
of acid sulphate of ammonium, in order to form in the solution itself the amount
of free muriatic acid necessary for the decomposition and solution of the tribasic
sulphate of lime. The process goes on in this wise that at last on the one hand
ammonia magnesia phosphate is formed which is held in solution by the free
muriatic acid, and on the other hand the three equivalents of lime of the tribasic
phosphate of lime combining with sulphuric acid come out of the concentrated
solution mostly as with difficulty soluble sulphate of lime.
Eventually the precipitation of the sulphate of lime may be aided by adding a
solution of sulphate of magnesium but this is not absolutely necessary and in the
first case a tolerably pure ammonia magnesia phosphate remains in the solution
which at the close of the treatment can be freed from the free muriatic acid by
heat, or in the hereinbefore described manner by neutralizing the free acid by
means of carbonate of lime or carbonate of magnesium and final addition of caustic
alkalies or caustic alkaline earths.
Although it is obvious I shall to prevent further explanations specially name
that the free magnesia, which through the extraction of the lime by chloride of
magnesium enters into the mass, may at once through suitable addition of muriatic
or sulphuric acid be rendered applicable for the further process of forming ammonia
magnesia phosphate.
The aforesaid process for obtaining phosphates is also suitable for such kinds of
slag from which the sulphur compounds and the free lime have not been removed
or have been removed by another process than the one described in the first part of
this specification, and it is only necessary to suitably apportion the addition of
chloride of magnesium or sulphate of magnesium and muriatic acid. Similarly
instead of the addition of chloride or sulphate of ammonium I may conduct
ammonia gas directly into the sufficiently acid solution,

page_text: COMPLETE SPECIFICATION.
I, ADOLPH FRANK Doctor of Philosophy of 80 Leibnitzstrasse Charlottenburg
near Berlin Prussia German Empire do hereby declare the nature of said invention
for "IMPROVEMENTS IN THE TREATMENT OF SLAG AND PHOSPHATES" and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :—
This process is for cleansing and dissolving or resolving slag of all kinds
especially the slag from iron smelting furnaces (which slag is not phosphatic) and
basic Bessemer slag (which is phosphatic) but also other naturally found or arti-
ficially produced phosphates or phosphatic materials and depends mainly on the
application of chloride of magnesium.
The molten liquid slag for instance is run into a sufficiently concentrated solution
of chloride of magnesium generally of a specific gravity of about 1.06 and is stirred
to the consistency of a powdery mass. The sulphides contained in the slag will
thereby be decomposed while sulphuretted hydrogen is evolved; also the free lime
contained in the basic slag combining with chloride of magnesium forms magnesia
and chloride of calcium and thus indirectly produces a concentration and greater
solubility of the phosphates contained in the slag, as for each 28 parts of oxide of
lime 20 parts of oxide of magnesium are required which latter may partly be
removed, by mixture and washing with water and settling. The powdery slag
with the still remaining or to be added chloride of magnesium is besides heated by
oxidizing flame and thus a partly higher oxidation is effected of the lower oxides
of iron (Fe O) and the like which are noxious for direct application as manure.
By this means the oxides are also made less soluble in acids.
Instead of letting the molten liquid slag run directly into the chloride of magnesium
solution the already cooled finely divided slag may of course also be treated with a
cold chloride of magnesium solution or under application of heat and by high steam
pressure in order to decompose the sulphur compounds contained in the slag and
to bring the free lime into solution by conversion into chloride of calcium.
The same method is also applicable for the cleansing and concentrating of
naturally found or artificially produced phosphates, especially such which contain
lime uncombined with phosphoric acid for instance phosphate-containing marl. If
such phosphates contain carbonate of lime the latter must be rendered caustic by
burning. Instead of the chloride of magnesium I may use its double salts together
with chloride of potash, chloride of lime or the like. Also, instead of the treat-
ment with watery solutions I may employ a smelting of the phosphorus-containing
materials with the said salts.
1
The slag or phosphates thus treated may be applied directly for manure purposes
or may in the known way be further treated for obtaining or concentrating the

page_text: The following mode for extracting and utilizing these phosphates is however
preferred:-
The phosphate-containing material is so treated with a chloride of magnesium
solution and an addition of chloride of ammonia and muriatic acid in about the
proportion of one equivalent of tribasic phosphate of lime for about rather more
than one of muriatic acid, and about two of chloride of magnesium and one of
chloride of ammonium. The muriatic acid dissolves the phosphate of lime and
transfers it again to the chloride of magnesium and the ammoniacal salt in
double decomposition in such manner, that chloride of calcium and ammonia-
magnesia phosphate are formed in the solution. The latter is precipitated after
the aforesaid conversions by neutralizing the free acid by means of carbonate of
lime or magnesia and final addition of caustic alkalies or caustic alkaline earths.
Instead of the chloride of magnesium and chloride of ammonium I may use in
about the aforesaid proportions sulphate of magnesium and sulphate of ammonium
together with free muriatic acid, that is to say, for one equivalent of tribasic
phosphate of lime two equivalents of sulphate of magnesium and one equivalent of
sulphate of ammonium together with somewhat more than one equivalent of
muriatic acid. The said sulphuric salts are either added directly, or in such
manner that they are added partly as chlorine compounds of the bases in question
by simultaneous addition of free sulphuric acid in a quantity equivalent to the
addition of chlorides which sulphuric acid again may be replaced by an equivalent
amount of acid sulphate of ammonium in order to form in the solution itself the
amount of free muriatic acid necessary for the decomposition. and solution of the
tribasic phosphate of lime. The process goes on in such manner that at last, and
on the one hand, ammonia-magnesia phosphate is formed which is held in solution
by the free muriatic acid, and on the other hand the greater part of the three
equivalents of lime the tribasic phosphate of lime combining with sulphuric acid
come out of the concentrated solution as less soluble sulphate of lime.
Eventually the precipitation of the sulphate of lime may be aided by adding a
solution of sulphate of magnesium but this is not absolutely necessary as also in
the first case a tolerably pure ammonia-magnesia phosphate remains in the solution
which at the close of the treatment may be freed from the free muriatic acid by
heat or in the herein before described manner by neutralizing the free acid by
means of carbonate of lime or carbonate of magnesium and final addition of caustic
alkalies or caustic alkaline earths.
Although it is obvious I shall to prevent further explanation specially name that
the free magnesia, which through the extraction of the lime by chloride of mag-
nesium enters into the mass, may at once through suitable addition of muriatic or
sulphuric acid be rendered applicable for the further process of forming ammonia-
magnesia phosphate.
The aforesaid process for obtaining phosphates is also suitable for such kind of
slag from which the sulphur compounds and the free lime have not been removed
or have been removed by another process than the one described in the first part
of this specification, and it is only necessary to suitably apportion the addition of
chloride of magnesium or sulphate of magnesium and muriatic acid. Similarly
instead of the addition of chloride or sulphate of ammonium I may conduct
ammonia gas directly into the sufficiently acid solution.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First-The application of chloride of magnesium or its combinations as double
salts with other chlorides for separating the sulphur combinations contained in
slag or phosphates and also for extracting the free lime or the lime caustified by
heat and if desired for the partial oxidizing in a higher degree of lower oxides of
iron manganese and others.

page_text: Second-The extraction and utilization of the phosphates contained in phosphate-
containing materials by transforming them into phosphate of ammonia-magnesia
by means of chloride of magnesium or sulphate of magnesia and ammonia or
suitable ammoniacal salts.