IMPROVEMENTS IN THE EXTRACTION OF MAGNESIUM
Year: 1885

page_text: I, EMIL VON PUTTNER of Hohenlohehütte near Kattowitz in the Kingdom of
Prussia and German Empire, Engineer do hereby declare the nature of my said
invention for IMPROVEMENTS IN THE EXTRACTION OF MAGNESIUM, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
__
Every mineral containing magnesium is capable of being utilized according to
the process which forms the subject of the present application for Letters Patent.
The preliminary preparation of the ore is effected by known methods according to
the nature of the material. Thus Magnesite and Dolomite are prepared by the
driving off of their carbonic acid, and Serpentine or Talc by dehydration, whilst
the compounds with acids are converted by chemical incans into pure magnesia.
The operation for the production of metallic magnesium by distillation is
conducted as follows: the substance containing magnesium is first intimately
mixed with oxide of iron and carbon, preferably wood charcoal, but coal, coke, or
graphite, or the bodies known as hydrocarbons might be used, and with or without
oxide of iron. The compound is then roasted in suitable vessels, preferably in
muffles or retorts, fixed in distillation-furnaces of the well known pattern, and
brought to a strong white heat.
In the first place, the oxide of iron, comparatively easily reduced at a red heat
to the metallic state, acts itself as a reducing material, because the reduced metal
when in intimate admixture with magnesia, produces metallic- magnesium and
oxides of iron, which latter are again converted in presence of excess of carbon
into metallic iron.
Besides this action, the carbon present reacts as in the manner described further
The reduced magnesium now escapes from the reducing hearth in the gaseous
state, and can be condensed in the well known manner.
on.
In the modification of the process already alluded to, the intimate admixture of
the incandescent carbon, with the body containing magnesium effects the reduction,
forming oxides of carbon, and liberating free magnesium, which at the white heat
at which the operation is conducted, escapes in the state of vapour. By passing
reducing or innocuous gases into the reducing vessel, the development of free
magnesium is materially assisted.
In general therefore, the process herein before described for obtaining metallic
magnesium has considerable resemblance to that in use for obtaining zinc, but the

page_text: operation of reducing magnesium requires not merely a more intimate mixture
of the materials, but the refractory bricks; retorts and the like used in the
construction of the furnaces employed in the process require to be selected with
greater care; for this purpose a mixture of clay or Bauxite, as rich as possible
in alumina, combined with dolomite or magnesite is most suitable, such a
composition being extremely refractory.
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
A method for extracting metallic magnesium, which method consists therein
that the mineral or product containing magnesium is closely mixed with iron oxide
and carbon or with carbon alone and this mixture is brought in closed vessels to
a white heat, whereby the over-distilling magnesium vapours are caught up in
receivers of well known shape.