Improvements in Methods and Processes of Reducing Ores.
Year: 1892

page_text: Date of Application, 29th Nov., 1892-Accented, 28th Jan., 1893
COMPLETE SPECIFICATION.
Improvements in Methods and Processes of Reducing Ores.
We, AUGUSTE JACQUES Rossi, Civil and Mining Engineer resident of
No. 62 East Eleventh Street, City, County and State of New York and United
States of America JAMES MACNAUGHTON, Civil Engineer resident. of No. 248
State Street, City and County of Albany, State of New York, United States
of America and WALTER DOUMAUX EDMONDS, Counsellor at Law, residence
Temple Court, No. 5 Beekman Street, City, County and State of New York,
United States of America, do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to improvements in methods and processes of reducing
ores, designated as titaniferous iron ores, being ores which contain an important
amount, say not less than four per centum, or thereabouts, of titanic acid, of which
the following is a description.
Notwithstanding that the great extent and accessibility of titaniferous ores and
the superior qualities of the iron produced therefrom have long been well known;
previous attempts to produce iron therefrom commercially have proved abortive,
because of the increased expense of reducing and fluxing these ores as compared to
others. This prohibitory increment was due to the fact, among others, that
heretofore the addition of silica, as an extra and special flux, has been deemed
indispensable to obtain a fusible slag.
Accordingly, for instance, in previous attempts to flux titaniferous ores large
quantities of quartz were charged into the furnace, in addition to limestone, as
fluxes, the result being a slag of substantially such composition as to reproduce
sphene or titanite, which, as is well known, is composed of about equal parts of
silica, titanic acid and lime, the proportion of silica to titanic acid reaching
occasionally as much as 1-13, the lime being reduced in proportion in such cases:
The amount of silica thus incorporated into the slag was about equal to the
titanic acid therein, and was in sufficient amount to produce a silicate which of
itself, was fusible independently of any titanic acid present, the latter being treated,
so to speak, as inert matter.
Thus the metallurgical treatment and reduction of these titaniferous ores has
heretofore involved the addition of special fluxes, besides those regularly used with
other ores free from titanic acid, and the addition of such special fluxes has been
deemed indispensable to obtain from titaniferous ores a sufficiently fusible slag.
These special fluxes added to the cost of treating titaniferous ores, not only the
direct item of the expense of obtaining and handling the same, but also indirectly
a considerable item of expense due to the extra burden thereby imposed upon the
furnace, since they unduly increased the amount of materials to slag, whereby the
amount of fuel was increased and also the productive capacity of the furnace
diminished.
The object of my invention is to provide a method or process of fluxing or treating
titaniferous ores which, without impairing the quality of the iron product, shall
be as simple, and economical, as other processes available for fluxing ores that are
not titaniferous. To this end I relegate to an entirely subordinate position the
silica heretofore supposed to be indispensable, and, in lieu thereof substitute as the.
essential element in the formation of the slag, the heretofore supposed objectionable

page_text: titanic acid, and I rely upon the latter as the essential and predominant factor to
slag the basic materials derived from the ores, fuel and fluxes added. Thus
primarily, and as one of the distinctive features of my invention and improved
method and process, I dispense wholly with the necessity of adding quartz as a flux,
as silica becomes in my process a mere accessory and comparatively unimportant
element in the slag, and its presence there may be treated as unimportant, and
fortuitous, its amount, compared to that of the titanic acid being always but a mere
fraction thereof and in many cases is reduced to almost nothing at all.
Many of the natural compounds of titanium, such as picrotanite and perofkite,
are known to be infusible. All those which, besides sphene, are fusible embody
silica in the ratio thereof to titanic acid of substantially 1:1 or even more and
the attempt to reproduce these fusible compounds in the slag would consequently
involve, as aforesaid, the addition of silica in fluxing without mentioning the
presence in these compounds of other elements either rare or unavailable in an
economical blast furnace practice.
Broadly stated my invention consists in so fluxing, without the intentional
addition of silica as a flux, that the titanic acid itself will act substantially the
same part as the silica has heretofore been employed to do in regard to the bases,
of the limestone, ashes of fuel, and gangues of ores, viz., alumina, lime and magnesia,
or such other bases as may occur and so that the titanic acid will form with them
fusible compounds predominating over all others in the slag, and whereby I am
enabled to dispense with any special or other fluxes than those used ordinarily in
blast furnace practice with ore free from titanic acid, and so that the presence of
no certain specific amount of silica in compounds, or slag, containing such titanic
acid, alumina, magnesia and lime or other bases is necessarily, or usefully, required
to effect or ensure their fusibility; and therefore, should silica be found, in any
considerable amount, (but always as a fraction of the titanic acid) in my slags its
presence there must be considered fortuitous and as an unavoidable incident
resulting from the composition of the ashes of fuel, limestone and gangue of ore.
As the construction and method of operation of an ordinary blast furnace, as
well as the treatment of the fuel, ores, and fluxes therein are all well understood
I do not deem it necessary to go into any description of these.
In employing my process I make use of all these in the usual way; but to the
titaniferous ore my
add, in the same way in which fluxes are usually added,
sufficient limestone dolomite, calcite, or other equivalent material, to furnish to the
titanic acid in addition to what is provided by the ashes of the fuel, enough bases
such as lime, alumina, and magnesia, or sufficient of any two of them, particularly
of alumina, and lime, to insure the predominance in the slag of multipletitanates
of these bases. The respective quantities of alumina, lime, and magnesia may
vary for the same quantity of titanic acid present in a slag, but I have obtained the
best results when the ratio of the oxygen of the acid elements of the slag (the
titanic acid and whatever silica, limestone or equivalent material, ashes of fuel,
and gangue of ore may be introduced) to the oxygen of all the bases present is
kept within, say substantially, the proportion of from two to one and a half
(2:1), to two to two (2:2). Such oxygen ratio would correspond to a pro-
portion of say 45 per cent. to 55 per cent. of total acid elements, to 55 per cent. to
45 per cent. of total basic elements.
As will be understood by metallurgists, it is impossible to prescribe any absolute
rule, or ratio of proportion for the various elements introduced into charges in
carrying out my process. Such proportions will necessarily vary in each case
according to the special conditions presented by the different ores and stones which
may be employed.
To illustrate, however, with greater definiteness, the principles involved in my
improvements I give the following tabulated statement showing what I find to be
useful proportions for the various elements entering into the composition of a charge,

page_text: divided for the purpose of computation into 200 parts, of which 100 are ore;
30 stone and 70 fuel, as follows, viz.:
100 lbs ora

page_text: assist in an understanding of what has been here said respecting different ratios
and proportions of various elements and resulting combinations made use of in my
process.
In making use of my process I do not find- it always necessary to use all three of
the bases mentioned in the same slag. For instance I am able to produce a good,
fusible, and liquid slag by the use of two of said bases, more especially so with
alumina and lime, the proportions of which to each other and to the other
elements of the charge will depend upon the special circumstances of each case and
will readily be determined by those skilled in the art. I may say generally that I
find that the best results are obtained, in using this diminished number of said
basic elements when the oxygen ratio of the acid and basic elements, of the slag
are kept within the same limits and relative proportions as when three earthy bases
are used as above described.
The composition of the furnace charges having thus been regulated so that the
titanic acid is provided with the basic elements,-alumina, lime and magnesia,-or
any two of them substantially as mentioned, and so as to result in the formation of
predominant titanates of said bases, the usual treatment of a blast furnace is
applied and the iron and slags separated in the usual manner.
In the foregoing description of the different bases which go to form the slags I
have not deemed it important to mention specifically the small quantities of ferrous
or manganous, oxides or alkalies usually found in these compounds because as far
as iron oxide is concerned it is the object of the blast furnace process to reduce this
iron in a slag to a minimum; and this irrespective of the question whether the ores
contain titantic acid or not, and the amount of such oxides present is too small
generally when the furnace is in normal working order, to effect materially, unless
it be to increase, the fusibility of the slag or its oxygen ratio.
I find it preferable in some cases to so regulate the constituents of the charge as
to incorporate therein, as an element, either of the fixed alkalies, potash, or soda,
or both, the amount of which may be regulated according to the total percentage
of silica furnished jointly by the various substances going to make up the charge,
that is to say, in the case of a substantially inappreciable a mount of silica say
one per cent., three or four per cent. of such alkalies or more might be used with
beneficial effect though in all cases the presence of such alkalies will facilitate the
fusibility of my slag and increase the fluidity.
The desired alkali may be incorporated into the charge in the shape of natural
alkali bearing rock, such as feldspar, or in the shape of common salt or wood
ashes, such rock, salt or ashes taking the place of so much equivalent limestone thus
not increasing the burden of the furnace."
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim, is :-
1. The process of fluxing titaniferous iron ores which consists in combining their
titanic acid with bases as fluxes so as to form in the slag predominant titanates of
two or more of those bases, and subjecting the combination to the usual heat and
treatment of a blast furnace substantially as and for the purpose described.
2. The process of fluxing titaniferous iron ores which consists in combining their
titanic acid with bases and fixed alkalies as fluxes so as to form in the slag
predominant titanates of those bases, and subjecting 'the combination to the
usual heat and treatment of a blast furnace, substantially as and for the purpose
described.
3. The process of fluxing titaniferous iron ores which consists in combining their
titanic acid with earthy bases as fluxes so as to form in the slag predominant
titanates of two or more of those bases, and without a sufficient amount of silica to
flux said bases, and subjecting the combination to the usual heat and treatment of
blast furnace, substantially as and for the purpose described.
4. The process of fluxing titaniferous iron ores which consists in combining their

page_text: titanic acid with earthy bases and fixed alkalies as fluxes so as to form in the slag
predominant titanates of those bases, and without a sufficient amount of silica to
flux said bases, and subjecting the combination to the usual heat and treatment of
a blast furnace, substantially as and for the purpose described.
5. The process of fluxing titaniferous ores consisting in combining them in and
subjecting them to the usual treatment and fusion of a blast furnace, in com-
bination with fuel, the earthy bases alumina, lime and magnesia, and without a
sufficient amount of silica to flux said bases substantially as and for the purpose
described.
6. The process of fluxing titaniferous ores consisting in combining them in and
subjecting them to the usual treatment and fusion of a blast furnace, in combination
with fuel, the earthy bases, alumina and lime, and without a sufficient amount of
silica to flux said bases, substantially as and for the purpose described.
7. The process of fluxing titaniferous ores consisting in combining them in and
subjecting them to the usual treatment and fusion of a blast furnace, in combination
with fuel, the earthy bases alumina and magnesia, and without a sufficient amount
of silica to flux said bases, substantially as and for the purpose described.
8. The process of fluxing titaniferous ores consisting in combining them in and
subjecting them to the usual treatment and fusion of a blast furnace, in combination
with fuel, the earthy bases lime and magnesia, and without a sufficient amount of
silica to flux said bases, substantially as and for the purpose described.
Dated this 20th day of November 1892.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.