IMPROVEMENTS IN THE TREATMENT OF ORES CONTAINING NICKEL, AND IN OBTAINING NICKEL AND SECONDARY PRODUCTS THEREFROM."
Year: 1876

page_text: "
PROVISIONAL SPECIFICATION left by Alfred Henry Allen at the Office of the
Commissioners of Patents on the 18th November 1876.
ALFRED HENRY ALLEN, of Sheffield, in the County of York, Analytical Chemist.
IMPROVEMENTS IN THE TREATMENT OF ORES CONTAINING NICKEL, AND IN
OBTAINING NICKEL AND SECONDARY PRODUCTS THEREFROM."
My Invention has for its object the extraction of nickel from such of its ores as
contain it, chiefly in the oxidized state, and the extraction of sulphate of magnesium
and other secondary products from the same ores.
The ores best suited for the purpose of my Invention are those known as
pimelite, genthite, rewdanskite, and garnierite, consisting chiefly of hydrated
silicates of nickel and magnesium mixed with variable quantities of iron compounds,
quartz, and chrome ore.
As my Invention has for one of its objects the production as secondary products
of the different varieties of sulphate of magnesium, including that known as Epsom
salts, the steps of my process are specially arranged to facilitate the production of
sulphate of inagnesium in a state of purity, and to increase the yield as much as
possible. For this purpose I treat the finely ground ore with sulphuric acid or
sulphuric acid and water, and apply heat to facilitate the composition, in some cases
carrying the temperature to dull redness; I then lixiviate the mass with water, and
thus obtain a residue of silica and undecomposed ore, and a liquor containing the
sulphates of nickel, iron, and magnesium, and occasionally of cobalt, copper, and
other metals. I then usually neutralize the solution of the ore, and separate the
iron by cautiously treating the boiling liquid with magnesia, after taking care that
the iron exists only in the condition of a ferric or per-salt, and if necessary I bring
it to this condition by the use of nitric acid, chlorine, or other convenient oxidizing
agent. The magnesia must be added in such quantity as to precipitate the iron
without any considerable quantity of nickel. With the iron alumina, arsenic, acid,
and other impurities become precipitated. Having separated the iron precipitate
by filtration or other convenient means I then throw down the nickel from the clear
solution by any re-agent which will cause its precipitation without throwing down
nagnesium compound at the same time, and of the many available re-agents I
prefer such as will facilitate rather than hinder the subsequent production of
sulphate or other compounds of magnesium from the liquid separated from the

page_text: nickel precipitate; as suitable precipitating agents I prefer the compounds of
magnesium.
If I desire to obtain the nickel in the form of sulphide I use solutions containing
sulphide, sulphydrate, polysulphide, or hyposulphite. of magnesium, or all of these
bodies; or I add sufficient magnesia to precipitate the oxides of nickel and any
other heavy metals which may be present, and then pass sulphuretted hydrogen gas
through the liquid..
If I desire to obtain the nickel in the form of oxide I prefer to treat the liquid
with magnesia or hydrate or carbonate of magnesium, or with hypochlorite of
magnesium, or several or all of these bodies, or with substances or solutions
containing them as principal constituents, but I do not limit myself to the
employment of magnesium compounds for the above purpose.
Of substances other than magnesium compounds I prefer to employ sulphide of
barium, the sulphide of nickel obtained being separated from the co-precipitated
sulphate of barium by re-solution in acid, and the nickel solution so obtained
treated with chalk and lime in the usual way for obtaining oxide of nickel; sulphide
of strontium may be substituted, sulphide of barium in the last process.
Most of the compounds of calcium are not well suited for my purpose, and I make
no claim to their use for precipitating nickel from the solution of the ore.
When the re-agent employed has caused the precipitation of sulphide of nickel
I convert that substance into oxide by any of the known methods, and treat the
resultant oxide, or that obtained by direct precipitation, in the usual way for the
production of metallic nickel. For most purposes any copper or cobalt which may
be precipitated with the nickel will not affect the quality of the product, and its
presence may be ignored, or it may be separated by any of the known methods.
From the liquid separated from the nickel precipitate I obtain sulphate of
magnesium by evaporation and crystallization in the usual way, or I employ it for
the production of other compounds of magnesium by double decomposition.