METHODE D'AMELIORATION ARTIFICIELLE DE LA SEPARATION MAGNETIQUE DES MINERAUX A L'AIDE DE REACTIFS PRECONDITIONNEURS

METHOD FOR ENHANCING ARTIFICIALLY MAGNETIC SEPARATION OF MINERALS BY THE USE OF PRECONDITIONING REAGENTS

Abrégé anglais

ABSTRACT OF THE DISCLOSURE
The present invention provides a method for the
benefication of ores and minerals which comprises crushing the
ores to a particulate size, conditioning the surface of ore or
mineral to be separated by treatment with a reagent so as to
selectively absorb on said surface a finely ground material
with strong ferro-magnetic or paramagnetic properties, treating
the conditioned ore or mineral with said finely ground material
to effect said selective absorption and separating the ore or
mineral which has absorbed said material by magnetic separation.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a beneficiation process for the recovery of pure
magnesite from magnesite ores containing magnesite, serpentine
and other gangue material which includes the crushing of a quan-
tity of magnesite ore, conditioning the crushed ore to activate
the surface of the serpentine and other gangue material, further
conditioning the crushed ore in a suspension of a finely divided
strongly ferromagnetic material so as to coat selectively the
surface of the serpentine and the other gangue material as well
as the strongly siliceous and carbonaceous particles of the ore,
and removing the serpentine and the other gangue material as well
as the strongly siliceous and carbonaceous particles of the ore
from the remainder of the ore by means of a magnetic separator to
obtain a concentrate of magnesite the improvement wherein said
conditioning of the crushed ore to active the surface of the ser-
pentine and other gangue material is accomplished by placing the
crushed ore in an aqueous mixture containing by weight 2% to 6%
diesel oil, 0.05% to 0.4% of pine oil and 0.05% to 0.4% of a
diamine.
2. The process of claim 1 wherein said diamine is an
alkyl propylene diamine.
3. The process of claim 2 wherein said alkyl propylene
diamine is selected from the group consisting of tallow deriva-
tive alkyl propylene diamines of the general formula RNHCH2CH=
CH NH2 wherein R ranges from C12 to C18.
4. A process as claimed in claim 3 in which R ranges
from C14 C18.
5. The process of claim 1, 2 or 3 wherein the aqueous
mixture contains, by weight, 4% diesel oil, 0.15% pine oil and
0.15% diamine.
6. The process of claim 1, 2 or 3 wherein the obtained

concentrate of magnesite is subjected to at least one additional
beneficiation process as defined in claim 1 to obtain a higher
quality concentrate.
7. The process of claim 1, 2 or 3 wherein after crush-
ing of the magnesite ore the ore is classified into particle size
fractions of less than 0.5 mm, between 0.5 and 6 mm, and greater
than 6 mm, and wherein only the fraction of between 0.5 to 6 mm
is subjected to the subsequent conditioning and separation steps.
8. The process of claim 1, 2 or 3 wherein prior to
subjecting the magnesite ore to crushing, it is mechanically pre-
concentrated to further effect a concentrate of the magnesite.

Description

1077441
The present invention relates to the separation of a
mineral from the gangue, or of the gangue from a mineral, by
selectively artificially increasing the magnetic properties of
the mineral or the gangue whereby magnetic separation of two
diamagnetic or slightly paramagnetic ores or minerals can be
accomplished by using magnetic separators of low or medium
strength.
According to the present invention therefore there is
provided in a beneficiation process for the recovery of pure
' 10 magnesite from magnesite ores containing magnesite, serpentine
and other gangue material which includes the crushing of a
quantity of magnesite ore, conditioning the crushed ore to
activate the surface of the serpentine and other gangue material,
further conditioning the crushed ore in a suspension of a finely
divided strongly ferromagnetic material so as to coat selective
the surface of the serpentine and the other gangue material as
well as the strongly siliceous and carbonaceous particles of
the ore, and removing the serpentine and the other gangue
material as well as the strongly siliceous and carbonaceous
particles of the ore from the remainder of the ore by means of
a magnetic separator to obtain a concentrate of magnesite the
improvement wherein said conditioning of the crushed ore to
activate the surface of the serpentine and other gangue material
is accomplished by placing the crushed ore in an aqueous mixture
containing by weight 2% to 6% of diesel oil, 0.05 to 0.4~ of pine
oil and 0.05 to 0.4% of a diamine.
Thus, in accordance with the present invention, the
increase of the magnetic properties of the ore or mineral to be
separated is achieved by selective absorption on its surface
of a finely divided highly magnetic substance, such as magnetic
or ferrosilicon and the so formed combination has increased
magnetic properties. This selective absorption is achieved by
conditioning the surface of the material to be magnetically

1077441
separated, by the appropriate reagents in water. The ore is
suitably conditioned in an aqueous suspension of finely divided,
strongly magnetic material, such asmagnetic or ferrosilicon.
This strongly magnetic material is selectively absorbed on the
surface of the ore and increases its magnetic properties.
After the magnetic separation, the recovery of the finely ground
magnetic material from the surface ~f theore may be achieved
with water under pressure or by using detergentsor by stirring
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strongly in a second magnetic field.
In a particular embodiment of the method of the
present invention, the ore or mineral is crushed into small
pieces, for example less than 6 mm., is thoroughly washed
and the pieces smaller than 0.5 mm are removed. It will however
be realized that the crushed ore may contain pieces larger
than 6 mm and smaller than 0.5 mm. The 0.5 mm - 6 mm.
material is fed into a conditioning tank with the appropriate
reagents where the conditioning is done under agitation. After
the conditioning, the conditioning liquid is separated. After
draining the liquid, the material is fed into another conditioner
with a finely divided suspension of magnetic or ferrosilicon,
and is well agitated until completely covered. After the
conditioning, during which the selective absorption of the
magnetic material on the surface of the particles to be magnetic-
ally removed has taken place, the mineral is drained, lightly
washed in order to remove magnetite or ferrosilicon from the
grains that have not absorbed these materials, and is then fed
~ in wet magnetic separators where the separation takes place.
20 The non-magnetic material is washed and according to its purity
constitutes the intermediate or final product. The magnetic
product is thoroughly washed with water under pressure or by
using a detergent or by stirring in a magnetic field, so that
the absorbed film of the highly magnetic material be removed.
The recovery of the finely ground magnetic material is achieved
by conventional methods, such as thickening, washing, magnetic
separationanddemagnetizing coils.
In one embodiment of the present invention in the
i method, the ore or mineral is firstly subjected to a mechanical
preconcentration step. Suitably the concentration obtained
is subjected to anotherbenefication method to improve its quality.
In another embodiment of the present invention, the

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method is repeated at least twice to the ore or mineral to
improve its quality.
The present invention will be further illustrated by
way of the following Example.
EXAMPLE -- -
A magnesite ore containing serpentine slightly magnetic
- and non-magnetic, feldspars and silica is subjected to the above
treatment. The conditioning was effected in an aqueous mixture
of 1) 0.15~ DUOMEET T* or GENAMIN TAP 100**
2) 0.18% FLOTOL B***
3) 4% DIESEL OIL
* DUOMEEN T is a trademark for an approximately 85~ pure diamine
of the general type RNH C3 H6 NH2 where R is an alkyl group of
- 8 to 18 carbon atoms with 99% chemical actives and is a tallow
derivative of fatty alkyl propyl diamine where the alkyl may vary
between C14 - C18 and is primarily C14, C16 and C18.
** GENAMIN TAP 100 is also a trademark for a diamine of the type
RNHCH2CH2NE2 (Tallow fatty alkyl propylene diamine where the
alkyl may vary between C12 - C18 and is primarily C12, C14,
C16, C17 and C18.
*** FLOTOL B is a trademark for a product which comprises pine
oil which contains particularly large quantities of terpene
alcohol.
The consumption of reagents, per ton of feed ore,
ranges between: 300 - 380 gr. DUOMEEN T or GENAMIN TAP 100
300 - 380 gr. FLOTOL B
7.7 - 8.7 lt. DIESEL OIL.
The recovery of concentrated ore depends on the initial
concentration of magnesite in the ore. The concentrate obtained
has a chemical analysis of 6% - 0.5% SiO2 depending on the initial
concentration and on the form of the ore. There is also a sub-
stantial reduction of CaO.
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. 10774~1
The method of the present invention has the following
advantages:
1. The reagents for the activation of the surface are
required in very small quantities, making the conditioning pro-
cess inexpensive;
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2. The method requires relatively coarse material,
provided that liberation can be accomplished at that size.
Expensive grinding usually required for flotation is thus
` avoided;
3. For the magnetic separation simple high output
equipments such as wet magnetic separators may be used; and
4. Almost complete recovery of the magnetic medium
used may be accomplished.
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