IMPROVE- MENTS IN CONNECTION WITH THE CALCINING OF SULPHUROUS ORES
Year: 1887

page_text: Date of Application, 20th July, 1887
Complete Left, 20th Apr., 1888
Complete Accepted, 25th May, 1888
I, JOHN FLEMING of Minas de Rio Tinto, Provincia de Huelva, Spain, Civil and
Mining Engineer do hereby declare the nature of the said invention for IMPROVE-
MENTS IN CONNECTION WITH THE CALCINING OF SULPHUROUS ORES to be as
follows:-
This Invention, which relates to improvements in connection with the calcining of
sulphurous ores, has for its object to prevent the dispersion or scattering over the
Country of the sulphurous acid and other fumes produced during the calcination or
roasting process. The Invention has also for its object to collect and condense the said
fumes in order to produce sulphuric and arsenious acids.
The Invention consists of an elongated hood whose shape corresponds to the shape
of the upper part of the bing or heap of mineral undergoing calcination.
The hood is formed of metallic plates bolted, rivetted or otherwise suitably con-
nected together and it is closed at the top, sides, and ends, but is open at the bottom;
the bottom edges resting all round upon or being embedded or sunk into the materials
constituting the bing or heap. At one end or side or other suitable part of the hood
a pipe or flue is led off communicating with sulphuric acid chambers in which the
sulphurous acid is in the well-known manner converted into sulphuric acid, whilst the
arsenious acid is condensed in the pipe or flue.
As in some cases it may happen that more air than is desirable will pass into the
pipe and flue, with the sulphurous acid fumes, this surplus air is reduced by passing
the whole or part of the fumes through one or more closed calcining furnaces into
which no air is admitted saving that which is mixed with the fumes taken thereinto.
The effect of this treatment is to add a further quantity of sulphurous acid to the
mixture and thereby to diminish the proportion of air present.
J. H. JOHNSON, DAY & JOHNSON,
115, St. Vincent Street, Glasgow,
Petitioner's Agents.

page_text: Improvements in Connection with the Calcining of Sulphurous
Ores.
I, JOHN FLEMING of Minas de Rio Tinto, Provincia de Huelva, Spain, Civil and
Mining Engineer do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particulaṛly described and ascertained in and by the
following statement :-
My Invention, which relates to improvements in connection with the calcining of
sulphurous ores, has for its object to prevent the dispersion or scattering over the
country of the sulphurous acid and other fumes produced during the calcination or
roasting process. The Invention has also for its object to collect and render suitable
for condensation the said fumes in order to produce sulphuric and arsenious acids.
My Invention consists of an elongated hood whose shape corresponds to the shape
of the upper part of the bing or heap of mineral undergoing calcination.
The hood is formed of metallic plates which may be protected internally against the
action of the fumes and rendered heat retaining by a non-conductive external
covering. The plates are bolted, rivetted or otherwise suitably connected together,
and the hood is closed at the top, sides and ends but is open at the bottom, the bottom
edges resting all round upon or being embebbed or sunk into the materials constituting
the bing or heap. At one end or side or other suitable part of the hood, a pipe or flue
is led off communicating with sulphuric acid chambers in which the sulphurous acid is
in the well-known manner converted into sulphuric acid, whilst the arsenious acid is
condensed in the pipe or flue.
As in some cases it may happen that more air than is desirable will pass into the
pipe and flue with the sulphurous acid fumes, this surplus air is reduced by passing the
whole or part of the fumes through one or more closed calcining furnaces into which
no air is admitted saving that which is mixed with the fumes taken thereinto. The
effect of this treatment is to add a further quantity of sulphurous acid to the mixture
and thereby to diminish the portion of air present.
In order that my Invention may be properly understood and readily carried into
effect, I have hereunto appended three explanatory sheets of drawings in the several
Figures of which corresponding parts are marked with the same letters of reference.
Figure 1, is a front elevation of a bing or heap A, undergoing calcination shewing
the apparatus constituting my Invention applied thereto.
Figure 2, is a plan of the same, and Figure 3, an end elevation of the bing or heap
but shewing the hood B, constituting part of my Invention in transverse section.
The hood B, is of such dimensions that it covers over the top portion of the burning
bing or heap A, enclosing about one third of the height thereof only as the smoke
and gases issuing from such heaps when calcining escape from about the upper one
third of the height thereof.

page_text: It is however to be understood that the hood B, is always of such dimensions as to
enclose that portion of a calcining bing or heap whether such portion be more or less
than one third of the height thereof. The hood B, is suspended from chains C, passed
over pulleys carried in the upper part or apex of the angle formed by the shear legs D.
In order to ensure rigidity of these shear legs D, the two pairs thereof are tied
together by cross-ties a, a, a, as shewn at Figures 1 and 2. The shear legs may be
constructed of malleable iron or steel tubing or of cast-iron tubes. As the hood B,
covers over that portion of the bing or heap from which heat and the sulphurous and
arsenious acids escape it protects the structure by which the hood is supported from
the action of the acids and from the hot mineral. The hood B, may be constructed
either of ribbed cast-iron plates bolted together and properly jointed or for the sake of
lightness it may be composed of buckled plates rivetted together. The interior of the
hood is provided with the necessary stays for maintaining it in shape and giving the
necessary support to the several parts thereof as more especially shewn in transverse
section at Figure 3. The interior of the hood is protected against the action of the fumes
by a coating of tar, or by tar, pitch ore and wax laid on hot. The exterior of the hood
is rendered as far as possible non-conducting by a coating of asbestos paint or by
a coating of ordinary non-conducting boiler covering coated with asbestos paint on
the outside or both the inside and outside of the hood may be protected by other
suitable means for preventing as much as possible the corrosion of the interior and
preventing as much as possible the escape of heat from the exterior. From the
hood B, a pipe E, leads to the duplicate flues F, and G, leading to sulphuric acid
chambers or to closed calcining furnaces. The flues F, and G, are shewn about the
capacity for collecting the fumes of gases for about eight bings or heaps, the portion
of the pipe E¹, shewn at Figure 2, representing a pipe corresponding to the pipe E,
leading from one of the other bings or heaps corresponding to the bing or heap A, not
shewn on the drawings but which are arranged in the opposite side of the flues F,
and G. These flues F, and G, may lead wholly or partly to close calcining furnaces
for rendering the gases suitable for condensation. In the event of the gases being too
highly charged with acid the admission of a further supply of air to the gases is
effected by means of dampers H, the details of which are not shewn on the drawings
but which may be of any suitable kind.
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
1. The hood or covering for the upper part of bings or heaps of mineral undergoing
calcination, the said hood boing supported in such a manner that no portion of
the supporting structure is exposed either to the action of the escaping sulphurous
acid or to the hot mineral substantially as hereinbefore described and shewn on the
annexed sheets of drawings.
2. The providing of the hood claimed in the preceding claiming clause for the
purpose of leading off the gases collected by the hood to sulphuric acid chambers or
to closed calcining furnaces substantially as hereinbefore described and shewn upon
the annexed sheets of drawings.
Dated this 10th dow of Anil 1888
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Applicant's Agent.