Note: Descriptions are shown in the official language in which they were submitted.
CA 02301482 2000-03-21
FIELD OF THE INVENTION
This invention relates generally to the assay and recovery of metals
and precious metals. More specifically, this invention relates to the
extraction of
metals and precious metals from complex ores and to their assay.
BACKGROUND OF THE INVENTION
In one specific embodiment, this invention relates to extraction of
metals and precious metals from complex ores derived from the venting of
sulphides during a marine environment.
Many complex ores exhibit great difficulties in determining their true
metal status and grade. Traditional fire assaying of complex ores have been
unable to quantify the ore samples and unable to repeat similar results of the
same samples.
Many physical techniques exist, such as electron microscope
technology, that can determine metal content from complex ores, however,
traditional fire-assaying techniques cannot collaborate and determine the ores
characteristics and values. Many complex ore bodies, large and small exist
around the world that cannot be exploited with the known traditional
beneficiating
processes.
The object of this invention is to prove that there is an alternative
economic solution for the recovery of metals and precious metals from
presently
known unexploitable complex ores.
DESCRIPTION OF THE INVENTION
Complex ores of metals and precious metals which also contain iron
spinals and similar compounds are assayed and their metals content is
extracted
by subjecting the ores or concentrates thereof together with an aluminum
reducing agent and certain other fluxing agents such as calcium oxide and
preferably a collector metal such as copper. When heated to a high temperature
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CA 02301482 2000-03-21
an aluminothermic reaction occurs and a melting point is reached to reduce all
of
the mixture, the metals with or without a collector metal and the non-
metallics to
the slag component. After cooling, separation of all metals can be achieved
either
through an electrolytic process or a selective chemical dissolution process,
leaving
all of the recovered metals for analysis and recovery. In some ores,
collecting
agents are not required. This process is scalable, meaning, either assaying or
a
beneficiating process for run of mine production.
More particularly, in one aspect the invention provides a method for
the assay and recovery of metals and precious metals from complex ores and
concentrates containing and consisting of iron, oxides and sulphides.
Preparing a
charge consisting essentially of complex ore together with fluxing agents such
as
calcium oxide, lime, limestone, sodium carbonate, sodium borate and mixtures
thereof and a reducing agent such as aluminum. The aluminothermic process is
to provide to total melting of all metals and gangue in the charge at an
extremely
high heat to provide a gravity separation of the heavier metals to a collector
metal, such as copper, when required.
The reducing agent may be a solid aluminum metal and more
particularly can consist of pure virgin aluminum or its various states in
scrap form.
The fusion reaction can reach temperatures in excess of 2000
degrees C but in any event, it is such that the separation of all metals with
or
without a collector metal is achieved.
The fluxing agents are reactive with silica to form a fluid slag at the
temperatures of the reaction.
Further, the separation of metals can be achieved electrolytically
when iron is present in the alloyed metals recovered.
Alternatively, metals and precious metals can be separated by
chemical dissolution by a reagent which selectively dissolves base metals
leaving
an undissolved residue comprising the precious metals.
As can be seen, the method of this invention provides considerable
benefit and advantages to the extraction of metals and precious metals from
various complex ores containing iron, various oxides and sulphides. While the
invention has been shown and described with reference to certain preferred
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embodiments, other modifications of the process will be readily apparent to
those
skilled in the art.
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