United States Patent [19]
Kindig et aI.
[11]
[45]
4,289,529
* Sep.15,1981
[54] PROCESS FOR BENEFICIATING SULFIDE
ORES
[21] Appl. No.: 102,626
[22] Filed: Dec. 11, 1979
Related U.S. Application Data
[63] Continuation-in-part ofSer. No. 950,175, Oct. 10, 1978,
abandoned.
[57] ABSTRACT
63 Claims, No Drawings
In a process for beneficiating one or more mineral values
of sulfide ores by treating the sulfide ore with a
metal containing compound under conditions such as to
selectively enhance the magnetic susceptibility of the
mineral values to the exclusion of the gangue in order to
permit a separation between the values and gangue, the
improvement comprising pretreating the sulfide ore by
heating it to a temperature of at least about 80° C. for at
least about 0.1 hours.
3,671,197 6/1972 Mascio 75/6
3,758,293 9/1973 Viviani et al. ; 75/6
3,926,789 1211975 Shubert 209/214
3,938,966 211976 Kindig et al. 44/1 R
4,056,38611/1977 McEwan et al. 423/417
4,098,584 7/1978 Kindig et al. ; 44/1 R
4,119,410 10/1978 Kindig et al. 44/1 R
4,120,665 10/1978 Kindig et al. 44/1 R
4,187,170 2/1980 Westcott 209/8
4,205,979 10/1980 Kindig et al. 209/214
FOREIGN PATENT DOCUMENTS
28375 7/1931 Australia 75/6
179095 7/1954 Austria 75/112
452790 11/1980 Canada 75/6
119156 8/1959 U.S.S.R 209/212
OTHER PUBLICATIONS
Henderson, J. G., et al. Metallurgical Dictionary, Rheinhold
Publishing Corp., N. Y. p. 227, (1953).
Sinclair,J. S.; Coal Preparation and Power Supply at
Collieries, London pp. 15-17, (1962).
Primary Examiner-MiChael L. Lewis
Attorney, Agent, or Firm-Sheridan, Ross, Fields &
McIntosh
James K. Kindig, Arvada; Ronald L.
Turner, Golden, both of Colo.
Hazen Research, Inc., Golden, Colo.
The portion of the term of this patent
subsequent to Jun. 3, 1997, has been
disclaimed.
Assignee:
Notice:
Inventors:
u.s. PATENT DOCUMENTS
933,717 9/1909 Lockwood et al 209/214
1,053,486 2/1913 Etherington 75/1 R
2,132,404 10/1938 Dean 423/25
2,332,309 10/1943 Drummond 427/252
2,612,440 9/1952 Altmann 75/0.5
2,944,883 7/1960 Queneau et al. ~ 75/0.5
3,220,875 11/1965 Queneau 427/217
3,252,791 5/1966 Frysinger et al. 75/119
3,323,903 6/1967 O'Neill et al. 75/0.5
3,466,167 9/1969 Illis et al. 75/112
3,490,899 1/1970 Krivisky et al. 423/25
3,669,644 6/1972 Sato 423/25
[56]
[51] Int. CI,3 C22B 1/00
[52] U.S. CI•........................................... 75/1 R; 75/7;
209/8; 209/9; 209/11
[58] Field of Search 75/1 R, 1 T, 6-9,
75/21,28, 72, 77,82, 87, 111, 122; 423/23, 138,
25; 209/8, 9, 212-214, 127 R, 127 A; 427/47,
252, 253, 255, 129, 132
References Cited
[75]
[73]
[ * ]
1
4,289,529
2
BEST MODE FOR CARRYING OUT THE
INVENTION
tives, for example, steam, nitrogen,hydrogen, carbon
monoxide, hydrogen sulfide, ammonia, and sulfur dioxide.
The process of the present invention is particularly
useful for concentrating sulfide· minerals.•The process
employs· the heat pretreatment of the sulfide ore with
10 heat or heat in conjunction with a gaseous additive, and
thereafter treating the ore with a metal containing compound
under. processing conditions such as to. selec~
tively enhance the magnetic susceptibility of various
mineral values contained within the ore. The treated
15 mixture can then be subjected to a physical separation
process to produce a beneficiated product.
The heat pretreatment of the present invention is·
conducted prior to initiating the reaction with the metal
containing compound. This pretreatment essentially
comprises heating the sulfide ore in order to render the
ore more receptive to the magnetic enhancement reaction.
The temperature and time of heating are interrelated,
and essentially higher temperatures require less
time. The particular time and temperature for the pretreatment
process will depend on the· particular ore
being beneficiated and also the metal containing com~
pounds with which the ore is later treated. The pretreatment
may occur over a relatively broad range of temperatures;
however, the temperature must not exceed
the decomposition temperature of the mineral value, or
the temperature above which substantial vaporization
would occur. It is generally preferred that the pretreatment
essentially comprise heating the ore to a temperature
ofat least about 80· C., more preferably from about
125· C. to about 450· C. and most preferably to a temperature
of from about 175· C. to about 250· C. It is
preferred that this heat pretreatment be done for a time
period of at least about 0.1 hours, more preferably from
about 0.20 to about 4 hours, and most preferably from
about 0.25 to about 2 hours.
The heat pretreatment need not be immediately followed
by the magnetic enhancement reaction. Hence,
the ore may be permitted to cool to ambient temperature,
or any other convenient temperature, prior to
conducting the magnetic susceptibility enhancement
reaction. However, if the heat pretreatment is conducted
at a temperature greater than the temperature of
the magnetic enhancement reaction, the ore must. be
cooled to at least the temperature at whichthe magnetic
enhancement reaction will be conducted.
It is generally preferred to maintain the heat pretreatment
temperature at least slightly above the temperature
of the magnetic enhancement reaction. This is not
an imperative requirement; however, improved results
are generally accomplished. The pretreating by heating
the ore is believed to change the ore either physically or
chemically and/or to volatilize various components
which can interfere with the magnetic enhancement
n::action. Therefore, if the magnetic enhancement reaction
is conducted at a temperature in excess of the pretreatment
temperature, it is possible that additional volatile
components could somewhat detrimentally affect
the magnetlc enhancement reaction.
The heat pretreatment step may be conducted in the
presence of one or more gaseous additives, and this is
preferable under many circumstances. Examples of
suitable gaseous additives include steam, nitrogen, hy-
DISCLOSURE OF THE INVENTION
CROSS-RELATED PATENT APPLICATIONS
PROCESS FOR BENEFICIATING SULFIDE ORES
TECHNICAL FIELD
This invention relates to a means for treating sulfide
ores to separate the mineral value(s) from gangue material
by selectively enhancing the magnetic susceptibility
of the mineral value(s) so that they may be separated
from the gangue.
BACKGROUND ART
This application is a continuation-in-part application 5
of U.S. Ser, No. 950,175 filed Oct. 10, 1978 now abandoned.
As is well-known, mining operations in the past for
recovering various metals, e.g., lead, copper, have utilized
high grade ore deposits where possible. Many of
these deposits have been exhausted and mining of lower 20
grade ores is increasing. The processing of these leaner
ores consumes large amounts of time, labor, reagents,
power and water with conventional processing.
In addition to the increased expense associated with
the extraction of these metals from low·grade ores, 25
proposed processes for separation of certain of the sulfide
ores are technically very difficult and involve elaborate
and expensive equipment. In many cases the expense
incurred by such separation would be greater
than the commercial value of the metal, such that the 30
mineral recovery, while theoretically possible, is economically
unfeasible.
Copending patent application "Process for Beneficiating
Sulfide Ores", Ser. No. 086,830 filed Oct. 22, 1979
teaches the treatment of sulfide ores with a metal con- 35
taining compound under conditions such as to selectively
enhance the magnetic susceptibility of the mineral
values to the exclusion of the gangue, allowing for
a separation of these values from the gangue. However,
it appears as though the presence of various volatile 40
compounds within the ore can have an adverse effect on
the recovery of mineral values in a process which enhances
the magnetic susceptibility ofthe mineral values.
Pretreating the raw sulfide ore with heat in order to
volatilize these various components, and thereafter se- 45
lectively enhancing the magnetic susceptibility of the
mineral values so that they may be separated from the
gangue, substantially enhances the effectiveness of the
separation of the mineral values from the gangue. Additionally,
pretreatment with heat, optionally in the pres- 50
ence of various gaseous additives, enhances the basic
process, apparently as a result of differing mechanisms.
The process of the present invention entails heat pre- 55
treatment of a sulfide ore selected from the group consisting
of the metal sulfides of Groups VIB, VIIB,
VIIIB, IB, lIB, IlIA, IVA, and VA, and thereafter
treating the sulfide ore with a metal containing compound
under conditions such that the magneticsuscepti- 60
bility of the ore is selectively enhanced to the exclusion
of the gangue. The affected. ore values may then be
separated from the gangue, preferably by means of a
magnetic separation.
The pretreatment is conducted at a temperature of at 65
least about 80· C., preferably for a time period ofat least
about 0.1 hours. The heat pretreatment step may also be
conducted in the presence of one or more gaseous addi4,289,529
4
magnetic material may first be removed by passing the
mixture through a magnetic separator. The nonmagnetic
portion obtained by this precleaning step is then
subjected to the treatment with a metal containing compound.
Prior to the treatment, the ore must be ground to
liberate the metal sulfide particles from the gangue
particles, if the respective components do not already
existin this liberated state. The ore may be crushed finer
than necessary to achieve liberation, but this is not generally
economically feasible. It is generally satisfactory
to crush the ore to at least about minus 14 mesh, although
many ores require grinding to minus 65 mesh or
finer.
Numerous metal containing compounds are capable
of enhancing the magnetic susceptibility of the metal
sulfides in accordance with the invention. Many iron
containing compounds possess the capability of enhancing
the magnetic susceptibility of the mineral values of
the ore, as long as the compound is adaptable so as to
bring the iron in the compound into contact with the
mineral value under conditions such as to cause an alteration
of at least a portion of the surface of the mineral
value.
Iron containing compounds capable of exerting sufficient
vapor pressure, with iron asa component in the
vapor, so as to bring the iron into contact with the value
at the reaction temperature are suitable, as well as other
organic and inorganic iron containing compounds
30 which can be dissolved and/or "dusted" and brought
into contact with the mineral value contained within the
ore. Preferred compounds within the vapor pressure
group are those which exert a vapor pressure, with iron
as a component in the vapor, of at least about 10 millimeters
of mercury, more preferably of at least about 25
millimeters of mercury and most preferably of at least
about 50 millimeters of mercury at the reaction temperature.
Examples of groupings which fall within this
vapor pressure definition include ferrocene and its derivatives
and beta-diketone compounds of iron. Specific
examples include ferrocene and iron acetylacetonate.
Other organic compounds which may be utilized to
enhance the magnetic susceptibility include those
which may be homogeneously mixed with a carrier
liquid and brought into contact with the components of
the ore. Such mixtures include, for example, solutions,
suspensions and emulsions. These compounds must be
such as to provide sufficient metal to contact the surface
of the mineral value. Suitable carrier liquids include, for
example, acetone, petroleum, ether, naphtha, hexane,
benzene and water; but this, of course, is dependent
upon the particular metal compound being employed.
Specific groupings include, for example, ferrocene and
its derivatives and the carboxylic acid salts of iron, such
as, iron octoate, iron naphthenate, iron stearate and
ferric acetylacetonate.
Additionally, solid organic iron containing compounds
capable of being directly mixed with the ore in
solid form possess the capability of enhancing the magnetic
susceptibility of the metal sulfides. The compound
must be in solid form at the mixing temperature and be
of sufficiently fine particle size in order to be able to be
well dispersed throughout the ore. The particle size is
preferably smaller than about 20 mesh, more preferably
smaller than about 100 mesh and most preferably
smaller than about 400 mesh. Compounds within this
grouping include ferrocene and its derivatives, iron salts
of organic acids and beta-diketone compounds of iron.
3
drogen, carbon monoxide, carbon dioxide, ammonia,
hydrogen sulfide, sulfur dioxide, methane, air, ethane,
propane, butane and other hydrocarbon compounds in
the gaseous state at the pretreatment temperature. Preferred
gaseous additives include steam, nitrogen, hydro- 5
gen, carbon monoxide, hydrogen sulfide, ammonia and
sulfur dioxide.
When these additives are employed, it is preferable
that they be employed in an amount of at least about 2,
more preferably at least about 12 and most preferably at 10
least about 120 cubic meters per hour per metric ton of
ore being processed.
A particularly preferred additive is steam. Heat pretreatment
with steam is preferably conducted within a
temperature range of from at least about 1000 C., more 15
preferably from about 1500 C. to about 4500 C., and
most preferably from about 1750 C. to about 2500 C.
Preferably, the pretreatment should be conducted for at
least about 0.1 hours, more preferably for at least about
0.25 hours, and most preferably for at least 0.5 hours. 20
The amount of water preferably ranges from about 1
weight percent to about 50 weight percent, more preferably
from about 5 weight percent to about 30 weight
percent and most preferably from about 10 weight percent
to about 25 weight percent, based on the weight of 25
the metal sulfide ore being treated.
After the ore has been subjected to this heat pretreatment,
it is then treated with a metal containing compound
in order to selectively enhance the magnetic
susceptibility of its various mineral values.
. "Enhancing the magnetic susceptibility" of the ore as
used herein is intended to be defined in accordance with
the following discussion. Every compound of any type
has a specifically defined magnetic susceptibility, which
refers to the overall attraction of the compound to a 35
magnetic force. An alteration of the surface magnetic
characteristics will alter the magnetic susceptibility.
The metal treatment of the inventive process alters the
surface characteristics of the ore particles in order to
enhance the magnetic susceptibility of the particles. It is 40
to be understood that the magnetic susceptibility of the
original particle is not actually changed, but the particle
itself is changed, at least at its surface, resulting in a
different particle possessing a greater magnetic susceptibility
than the original particle. For convenience of 45
discussion, this alteration is termed herein as "enhancing
the magnetic susceptibility" of the particle or ore
itself.
The sulfide minerals which are capable of undergoing
a selective magnetic enhancement in accordance with 50
the process include the metal sulfides of groups VIB,
VIIB, VIlIB, IB, IIB, IlIA, IVA, and VA. These sulfides
preferably specifically include the sulfides of molybdenum,
tungsten, manganese, rhenium, iron, ruthenium,
osmium, cobalt, rhodium, iridium, nickel, palla- 55
dium, platinum, copper, gold, silver, zinc, cadmium,
mercury, tin, lead, arsenic, antimony and bismuth.
The gangue minerals from which the metal sulfides
can be separated include those minerals which do not
undergo a sufficient magnetic susceptibility enhance- 60
ment as a result of the process. These gangue minerals
include, for example, silica, alumina, gypsum, muscovite,
dolomite, calcite, albite and feldspars, as well as
various other minerals. The term gangue as used herein
refers to inorganic minerals with which sulfide ores are 65
normally associated. The term does not include coal.
In those ores which contain naturally relatively
strongly magnetic constituents, such as magnetite, the
EXAMPLE 1
Samples ofdifferent minerals were ground to a minus
65 mesh and mixed with minus 65 mesh silica sand to
produce 3 percent synthetic ores with the exception of
molybdenite which was a 5 percent ore. A sample of
each ore was pretreated with steam by rapidly heating a
reactor containing the sample to 200° C. under a nitrogen
purge; thereafter the sample was treated for 15
minutes with 200 kilograms of steam per metric ton of
sample. The·reactor was then cooled under.a nitrogen
purge. Following this pretreatment, each sample was
treated with· 8 kilograms of iron pentacarbonyl per
metric ton of sample for 30 minutes at the temperature
indicated in Table 1. For comparative purposes,· a sample
of each of these ores was only pretreated with the
steam in the manner indicated above. All of the samples
were then subjected to a wet magnetic separation process,
and the analyses of the products thus obtained are
presented below in Table 1.
TABLE 1
4,289,529
5 6
Specific examples include ferrous formate, 1, l'-diacetyl methods and often a trial and error approach is preferrocene
and l,l'-dihydroxymethyl ferrocene. ferred to determine the precise temperature range for
Various inorganic compounds are also capable of each specific system.
producing an enhanced magnetic susceptibility. Pre- The amount of the metal containing compound used
ferred inorganic compounds include ferrous chloride, 5 and the time of treatment can be varied to maximize the
ferric chloride and the metal carbonyls, including, for selective enhancement treatment. With respect to iron
example, iron, nickel, cobalt, molybdenum, tungsten carbonyl, the preferred amount employed is from about
and chromium carbonyls and derivatives of these com- 0.1 to about .100 kilograms per metric ton of feed, more
pounds. Iron carbonyl is a preferred carbonyl for im- preferably from about.1 to about 50 kilograms per metparting
this magnetic susceptibility, particularly iron 10 ric ton of feed and most preferably from about 2 to 20
pentacarbonyl, iron dodecacarbonyl, and iron nonacar- kilograms peimetric ton of feed. The treatment reacbonyl.
The more preferred metal containing com- tion is generally conducted for a period of time of from
pounds capable of enhancing the magnetic susceptibil- about 0.05 to about 4 hours, more preferably from about
ity are iron pentacarbonyl, ferrocene and ferric acetyl- 0.15 to about 2 hours and most preferably from about
acetonate, with iron pentacarbonyl being the most pre~ 15 0.25 to about 1 hour.
ferred. After the feed mixture containing the metal sulfide
The process is applied by contacting the iron contain- values has been treated with a metal containing coming
compound with the ore at a temperature wherein pound, it can then be subjected to a magnetic separation
the iron containing compound selectively decomposes process to effect the separation of the sulfides. Any of
or otherwise reacts at the surface of the metal sulfide 20 many commercially available magnetic separators can·
particles to alter their surface characteristics, while be used to remove these values from the gangue. For
remaining essentially unreactive, or much less reactive, example, low or medium intensity separations· can be
at the surface of the gangue particles. The temperature made with a permanent mag~etic drum separator,elecof
the reaction is a critical parameter, and dependent tromagnetic drum separators,induced roll separators or
primarily upon the particular compound and the partic- 25 other configurations known to those skilled in the art.
ular ore. The preferred temperature can be deteiminedSince most sulfides are liberated at a mesh size of 65
by heating a sample of the specific iron containing com- mesh or fmer, .. a wet magnetic separation process is
pound and the specific ore together until the decompo- more effective. Thus, high intensity, high gradient wet
sition reaction occurs. Suitable results generally occur .magnetic separators are preferred. Also electrostatic
over a given temperature range for each system. Gener- 30 techniquesniay be employed as the primary separation
ally, temperatures above the range cause non-selective means, or in addition to the magnetic separation means.
decomposition while temperatures below the range are· The selective changeinsnrface characteristics changes
insufficient for the reaction to occur. the electrical conductivity of the particle in analogous
While as indicated abo,!e, techniques other than fashion to changing the particle's magnetic characterisvapor
injection methods may be employed as applicable 35 tics. Additioilally,due to the fact that the sulfide surface
depending upon the metal containing compound being characteristics have been altered, the sulfides are ofteil
utilized, the following discussion primarily applies to more amenable to processes such as froth flotation and
vapor injection techniques, specifically iron pentacar, chemical leaching.
bonyl, as these are generally preferred. Similar considerations,
as can be appreciated, apply to the other de- 40
scribed techniques.
The preferred temperatures when iron pentacarbonyl
is employed as the treating gas are primarily dependent
upon the ore being treated. It is generally preferred to
select a temperature which is within a range of 125° C., 45
more preferably 50° C. and most preferably 15° C.less
than the general decomposition temperature of the iron
carbonyl in the specific system. The general decomposi-·
tion temperature is intended to mean the temperature at
which the iron carbonyl decomposes into iron and car- SO
bon monoxide in indiscriminate fashion, causing a magnetic
enhancement of the gangue as well as the metal
sulfide. The "specific system" is intended to include all
components and parameters, other than, of course, temperature
of the precise treatment, as the general decom- 55
position temperature varies ·with different components
and/or different parameters. This decomposition tem"
perature range can be readily determined by analytical
Mineral
Galena
Galena
Pretreatment
Steam
Steam blank
Temp. of
Fe(CO)s
Treatment Weight Grade Metal
. ('C.) Product (%) (%) Metal Distr.
135 Magnetic 3.9 52.7 Pb 86.6
Nonmagnetic 96.1 0.33 Pb 13.4
Calculated Feed 100.0 2.37 Pb 100.0
Magnetic 0.48 17.2 Pb 3.3
.Nonmagnetic 99.52 2.42 Pb 96.7
4,289,529
7 8
TABLE I-continued
Temp. of
Fe(CO)s
Treatment Weight Grade Metal
Mineral Pretreatment ('c.) Product (%) (%) Metal Distr.
Calculated Feed 100.0 2.49 Pb 100.0
Molybdenite Steam 135 Magnetic 36.4 0.45 Mo 89.0
Nonmagnetic 63.6 0.032 Mo 11.0
Calculated Feed 100.0 0.18 Mo 100.0
Molybdenite Steam blank Magnetic 0.48 2.73 Mo 7.8
Nonmagnetic 99.52 0.156 Mo 92.2
Calculated Feed 100.0 0.168 Mo 100.0
Stibnite Steam 85 Magnetic 1.2 24.1 Sb 44.4
Nonmagnetic 98.8 0.367 Sb 55.6
Calculated Feed 100.0 0.652 Sb 100.0
Stibnite Steam Blank Magnetic 0.64 4.50 Sb 3.3
Nonmagnetic 99.36 0.847 Sb 96.7
Calculated Feed 100.0 0.87 Sb 100.0
Smaltite Steam 115 Magnetic 0.72 4.96 Co 11.6
Nonmagnetic 99.28 0.275 Co 88.4
Calculated Feed 100.0 0.309 Co 100.0
Smaltite Steam blank Magnetic 0.84 2.40 Co 6.6
Nonmagnetic 99.16 0.29 Co 93.4
Calculated Feed 100.0 0.31 Co 100.0
Chalcopyrite Steam 140 Magnetic 4.4 17.1 Cu 81.4
Nonmagnetic 95.6 0.18 Cu 18.6
Calculated Feed 100.0 0.924 Cu 100.0
Chalcopyrite Steam blank Magnetic 2.3 26.3 Cu 69.6
Nonmagnetic 97.7 0.271 Cu 30.4
Calculated Feed 100.0 0.87 Cu 100.0
Orpiment Steam 110 Magnetic 12.6 9.06 As 85.8
Nonmagnetic 87.4 [0.22]· As 14.2
Calculated Feed 100.0 1.33 As 100.0
Orpiment Steam blank Magnetic 0.61 10.8 As 5.0
Nonmagnetic 99.39 1.27 As 95.0
Calculated Feed 100.0 1.33 As 100.0
Cinnabar Steam 190 Magnetic 3.0 23.9 Hg 54.8
Nonmagnetic 97.0 0.61 Hg 45.2
Calculated Feed 100.0 1.31 Hg 100.0
Cinnabar Steam blank Magnetic 0.72 14.9 Hg 7.0
Nonmagnetic 99.28 1.43 Hg 93.0
Calculated Feed 100.0 1.53 Hg 100.0
Bornite Steam 140 Magnetic 15.1 8.95 Cu 89.9
Nonmagnetic 84.9 0.178 Cu 10.1
Calculated Feed 100.0 1.50 Cu 100.0
Bornite Steam blank Magnetic 2.4 49.5 Cu 80.0
Nonmagnetic 97.6 0.304 Cu 20.0
Calculated Feed 100.0 1.49 Cu 100.0
Realgar Steam 95 Magnetic 33.3 3.88 As 89.0
Nonmagnetic 67.7 0.24 As 11.0
Calculated Feed 100.0 1.45 As 100.0
Realgar Steam blank Magnetic 0.53 2.25 As 0.8
Nonmagnetic 99.47 1.56 As 99.2
Calculated Feed 100.0 1.56 As 100.0
Pentlandite Steam 105 Magnetic 2.6 7.65 Ni 91.1
Nonmagnetic 97.4 0.02 Ni 8.9
Calculated Feed 100.0 0.22 Ni 100.0
Pentlandite Steam blank Magnetic 3.0 7.93 Ni 49.5
Nonmagnetic 97.0 0.25 Ni 50.5
Calculated Feed 100.0 0.48 Ni 100.0
Tetrahedrite Steam 117 Magnetic 2.5 4.65 Cu 70.5
Nonmagnetic 97.5 0.05 Cu 29.5
Calculated Feed 100.0 0.165 Cu 100.0
Tetrahedrite Steam blank Magnetic 2.9 5.18 Cu 83.8
Nonmagnetic 97.1 0.03 Cu 16.2
Calculated Feed 100.0 0.179 Cu 100.0
·Values in brackets are calculated from other analyses.
EXAMPLE 2
60 type of nitrogen purge. Following this pretreatment
Samples of different synthetic ores were prepared as each sample was treated with 8 kilograms of iron pentaindicated
in Example 1. A sample of each of the ores carbonyl per metric ton of sample for 30 minutes at the
was pretreated with heat and nitrogen by rapidly heat- temperature indicated for the particular ore in Table 1.
ing a reactor containing the sample to 400· C. during a For comparative purposes, a sample of each of the ores
nitrogen purge which flowed at a rate of one reactor 65 was merely subjected to the heat and nitrogen pretreatvolume
of gas being introduced into the system every ment in the manner indicated above. All of the samples
4.3 minutes and maintaining these conditions for 15 were then subjected to a magnetic separation process.
minutes. Then the reactor was cooled under the same The results are presented in Table 2
9
4,289,529
10
TABLE 2
Weigit Grade Metal
Mineral Pretreatment Product (%) (%) Metal Distr.
Galena Heat & NZ Magnetic 46.9 3.60 Pb 77.6
Nonmagnetic 53;1 0.9i7 Pb 22.4
Calculated Feed 100.0 2.18 Pb 100.0
Galena Heat & Nz blank Magnetic 0.66 6.51 Pb 1.9
Nonmagnetic 99.34. 2.24 Pb 98.1
Calculated Feed )00.0 2.27 Pb 100.0
Sphalerite Heat & N2 Magnetic 33.1 5.08 Zn 90.7
Nonmagnetic 66.9 0.259 Zn 9.3
Calculated Feed 100.0 1.85 Zn 100.0
Sphalerite Heat & N2 blank Magnetic 0.41 10.9 Zn 2.9
Nonmagnetic 99.59 1.53 Zn 97.1
Calculated Feed 100.0 1.57 Zn 100.0
Molybdenite Heat & N2 Magnetic 41.2 0.29 Mo 94.0
Nonmagnetic 58.8 0.013 Mo 6.0
Calculated Feed 100.0 0.127 Mo 100.0
Molybdenite Heat & N2 blank Magnetic 0.49 1.33 Mo 3.7
Nonmagnetic 99.51 0.172 Mo 96.3
Calculated Feed 100.0 0.178 Mo 100.0
EXAMPLE 3
the products thus obtained are given below in Table 3.
TABLE 3
Weight Grade Metal
Mineral Pretreatment Product (%) (%) Metal Distr.
Galena Heat & H2 Magnetic 29.9 6.77 Pb 88.9
Nonmagn.etic 70.1 0.359 Pb 11.1
Calculated Feed 100.0 2:28 Pb 100.0
Galena Heat & H2 blank Magnetic 0.78 .11.4 Pb 4.1
Nonmagnetic 99.22 2.11 Pb 95.9
Calculated Feed 100.0 2.18 Pb loo~O
Sphalerite Heat & Hz Magnetic 12.8 11.6 Zn 87.4
Nonmagnetic 87.2 0.246 Zn 12.6
Calculated Feed 100.0 1.70 Zn 100.0
Sphalerite Heat & H2 blank Magnetic 0.94 5.58 Zn 3.2
Nonmagnetic 99.06 1.58 Zn 96.8
Calculated Feed 100.0 1.62 Zn 100.0
EXAMPLE4
Samples of different synthetic ores were prepared as
indicated in Example 1. A sample of each of the ores
was pretreated with heat and carbon monoxide by rapidly
heating the reactor containing the sample to 400" C.
while purging it with nitrogen. This temperature was
maintained for 15 minutes while carbon monoxide gas
was passed through the reactor at a flow rate of one
reactor volume every 4.3 minutes. The reactor was then
cooled under a purge of nitrogen gas. Each sample was
then treated with 8 kilogramsofiron pentacarbonyl per
metric ton of sample for 30 minutes at the temperature
indicated for the particular ore in Table 1. For comparative
purposes, a sample of each ore was subjected to just
the heat and carbon monoxide pretreatment. All of the
samples underwent a wet magnetic separation process.
55 The results are given below in Table 4.
Samples of different synthetic ores were prepared as
indicated in Example 1 and a sample of each of the ores
was pretreated with heat and hydrogen by rapidly heat- 40
ing the reactor containing the sample to 400" C. while
purging it with nitrogen. This temperature was maintained
for 15 minutes while hydrogen gas was passed
through the reactor at a flow rate ofone reactor volume
of gas being introduced into the system every 4.3 min- 45
utes. The reactor was cooled under a purge of nitrogen
gas. Each sample was then treated with 8 kilograms of
iron pentacarbonyl per metric ton of samples for 30
minutes at the temperature indicated for the particular
ore in Table 1. For comparative purposes, a sample of 50
each of the ores was subjected to just the heat and hydrogen
pretreatment. All of the samples were subjected
to a wet magnetic separation process. The analyses of
TABLE 4
Weight Grade Metal
Mineral Pretreatment Product (%) (%) Metal Distr.
Galena Heat&CO Magnetic 41.8 4.61 Pb 92.1
Nonmagnetic 58.2 0.286 Pb 7.9
Calculated Feed 100.0 2.09 Ph 100.0
Galena Heat & CO blank Magnetic 0.57 15.0 Pb 3.8
Nonmagnetic 99.43 2.20 Pb 96.2
Calculated Feed 100.0 2.27 Pb 100.0
Molybde.lite Heat & CO Magnetic 8.6 1.97 Mo 96.3
. Nonmagnetic 91.4 0.007 Mo 3.7
Calculated Feed 100.0 0.174 Mo 100.0
Molybdenite Heat & CO blank tvfagnetic 0.80 1.58 Mo 7.2
Nonmagnetic 99.20 0.164 Mo 92.8
4,289,529
11 12
TABLE 4-continued
Mineral Pretreatment Product
Weight Grade
(%) (%) Metal
Metal
Distr.
Calculated Feed 100.0 0.175 Mo 100.0
over a 2 hour period. The system was purged with
nitrogen prior to and following the ferrocene treatment.
Finally, the samples were subjected to a wet magnetic
10 separation process. Each of the pretreatments, i.e.,
steam, heat plus nitrogen, heat plus hydrogen, and heat
plus carbon monoxide, were conducted in the same
manner as the pretreatments in Examples 1,2, 3 and 4,
respectively.
For comparative purposes, additional samples of the
same type of ores were subjected to just the pretreatment
followed by magnetic separation. Also, two samples
of this ore were given no pretreatment. One was
subjected to only the ferrocene treatment and the other
EXAMPLE 5
For comparative purposes, a sample of each of the
same type of ores used in the preceeding examples were
not given any pretreatment, but were just treated with 8
kilograms of iron pentacarbonyl per metric ton of feed
for 30 minutes at the same temperature as used in the
preceeding examples. Additionally, some samples of
these ores were treated at the temperature of the iron 15
carbonyl treatment but received no iron carbonyl. All
of the samples were magnetically separated and the
analyses of the products thus obtained are presented
below in Table 5.
TABLE 5
Fe(CO)5 Temp. Weight Grade Metal
Mineral Treatment ('C) Product (%) (%) Metal Distr.
Galena yes 135 Magnetic 45.8 3.07 Pb 69.5
Nonmagnetic 54.2 1.14 Pb 30.5
Calculated Feed 100.0 2.02 Pb 100.0
Galena no 135 Magnetic 0.45 11.2 Pb 2.2
Nonmagnetic 99.55 2.23 Pb 97.8
Calculated Feed 100.0 2.27 Pb 100.0
Sphalerite yes 135 Magnetic 36.5 3.50 Zn 70.5
Nonmagnetic 63.5 0.842 Zn 29.5
Calculated Feed 100.0 1.81 Zn 100.0
Sphalerite no 135 Magnetic 0.37 12.9 Zn 2.7
Nonmagnetic 99.63 1.71 Zn 97.3
Calculated Feed 100.0 1.75 Zn 100.0
Molybdenite yes 135 Magnetic 51.8 0.249 Mo 95.7
Nonmagnetic 48.2 0.012 Mo 4.3
Calculated Feed 100.0 0.135 Mo 100.0
Molybdenite no 135 Magnetic 1.13 2.24 Mo 13.3
Nonmagnetic 98.87 0.167 Mo 86.7
Calculated Feed 100.0 0.190 Mo 100.0
Stibnite yes 85 Magnetic 7.6 4.82 Sb 47.8
Nonmagnetic 92.4 0.43 Sb 52.2
Calculated Feed 100.0 0.77 Sb 100.0
Smaltite yes 115 Magnetic 1.2 5.37 Co 22.1
Nonmagnetic 98.8 0.23 Co 77.9
Calculated Feed 100.0 0.29 Co 100.0
Chalcopyrite yes 140 Magnetic 1.8 20.5 Cu 48.4
Nonmagnetic 98.2 0.401 Cu 51.6
Calculated Feed 100.0 0.77 Cu 100.0
Orpiment yes 110 Magnetic 20.1 2.00 As 40.0
Nonmagnetic 79.9 0.74 As 60.0
Calculated Feed 100.0 0.99 As 100.0
Cinnabar yes 190 Magnetic 1.6 48.1 Hg 43.9
Nonmagnetic . 98.4 1.0 Hg 56.1
Calculated Feed 100.0 1.75 Hg 100.0
Bornite yes 140 Magnetic 3.6 29.7 Cu 78.3
Nonmagnetic 96.4 0.313 Cu 21.7
Calculated Feed 100.0 1.38 Cu 100.0
Arsenopyrite yes 125 Magnetic 7.4 1.01 As 31.0
Nonmagnetic 92.6 0.18 As 69.0
Calculated Feed 100.0 0.24 As 100.0
Realgar yes 95 Magnetic 23.2 2.02 As 36.5
Nonmagnetic 76.8 1.06 As 63.5
Calculated Feed 100.0 1.28 As 100.0
Pentlandite yes 105 Magnetic 18.2 0.733 Ni 67.4
Nonmagnetic 81.8 0.079 Ni 32.6
Calculated Feed 100.0 0.198 Ni 100.0
EXAMPLE 6
Samples of galena were made into 3 percent synthetic
ores as indicated in Example 1. Each of these samples
was subjected to a pretreatment and thereafter treated 65
with 16 kilograms offerrocene per metric ton of sample.
The ferrocene was mixed with the sample and the temperature
of the reactor was slowly raised to 4000 C.
merely to a heating to a temperature of 4000 C. These
samples were subjected to wet magnetic separation
process. The results of these comparative samples are
given below in Table 6.
EXAMPLE 8
Samples of molybdenite were made into 5 percent
10 synthetic ore as indicated in Example 1. Each of these
samples was subjected to a pretreatment and thereafter
treated with 16 kilograms of ferrocene per metric ton of
sample. Each of the pretreatments, i.e., steam, heat plus
nitrogen, heat plus hydrogen and heat plus carbon mon-
15 oxide were conducted in the same manner as the pretreatments
in Examples 1, 2, 3 and 4, respectively; The
ferrocene treatment was conducted in the manner described
in Example 6. For comparative purposes, additional
samples of the same type of ore were subjected to
20 just the pretreatment followed by magnetic separation.
Also, samples of this ore were given no pretreatment.
One was subjected to only the ferrocene treatment, and
the other was merely heated to 4000 C. AIl of the.sampIes
were subjected to a magnetic separation process.
25 Analyses of the products thus obtained. are presented
below in Table 8.
TABLE 8
Molyb.
Weight Grade denum
Product (%) (%) Distr.
Magnetic 1.5 2,90 21.2
Nonmagnetic 98.5 0.164 78.8
Calculated Feed 100.0 0.20S 100.0
Magnetic 0.48 2.73 7.8
Nonmagnetic 99.52 0.156 92.2
Calculated Feed 100.0 0.168 100.0
Magnetic 1.3 1.54 11.2
Nonmagnetic. 98.7 0.161 88.8
Calculated Feed 100.0 0.179 100.0
Magnetic 1.05 2.11 12.7
Nonmagnetic 98.95 0.154 87.3
Calculated Feed 100.0 0.175 100.0
Magnetic 2.0 1.30 14.2
Nonmagnetic 98.0 0.160 85.8
Calculated Feed 100.0 0.183 100.0
Magnetic 0.80 1.58 7.2
Nonmagnetic 99.20 0.164 92.8
Calculated Feed 100.0 0.175 100.0
Magnetic 11.8 0.953 66.6
Nonmagnetic 88.2 0.064 33.4
C8Jculated Feed 100.0 0.165 100.0
Magnetic 0.68 0.961 4.4
Nonmagnetic 99.32 0.143 95.6
Calculated Feed 100.0 0.148 100.0
14
Weight Grade Zinc
Product (%) (%) Dist~.
TABLE 7-continued
. Calculated Feed 100.0 1.65 100.0
Heat&H2
Heat & H2 blank
Heat & CO blank
Steam
Heat&CO
Steam blank
Pretreatment
5
4,289,529
30
Pretreatment
EXAMPLE 7
Samples of sphalerite were made into 3 percent synthetic
ores as in.dicated in Example 1. Each of these 35
samples was subjected to a pretreatment and thereafter
treated with 16 kilograms offerrocene per metric ton of
sample. Each of the pretreatments, i.e., steam and heat
plus nitrogen, were conducted in the same manner as
the pretreatments in Examples 1 and 2, respectively. 40
The ferrocene treatment was conducted in the same
manner as described in Example 6. For comparative
purposes, additional samples of the same type of ore
were subjected .to just the pretreatment followed by
magnetic separation. Saijlples of this ore were also 45
given no pretreatment with one sample being subjected
to only the ferrocene treatment and the other merely None
being heated to 4000 C. All of the samples underwent a (heat to 400° c.
magnetic separation process. Analyses of these compar- and .
ferrocene)
ative samples are given below in Table 7. 50 None
TABLE 7 (heat to 400° C.)
13
TABLE 6
Weight Grade Lead
Pretreatment Product (%) (%) Distr.
Steam Magnetic 3.9 23.6 38.5
Nonmagnetic 96.1 1.53 61.5
Calculated Feed 100.0 2.39 100.0
Steam Blank Magnetic 0.48 17.2 3.3
Nonmagnetic 99.52 2.42 96.7
Calculated Feed 100.0 2.49 100.0
Heat & Jilz Magnetic 1.6 17.9 10.8
Nonmagnetic 98.4 2.41 89.2
Calculated Feed 100.0 2.66 100.0
Heat & Nz blank Magnetic 0.66 6.51 1.9
Nonmagnetic 99.34 2.24 98.1
Calculated Feed 100.0 2.27 100.0
Heat & CO Magnetic 1.4 23.9 15.6
Nonmagnetic 98.6 1.83 84.4
Calculated Feed 100.0 2.14 100.0
Heat & CO blank Magnetic 0.57 15.0 3.8
Nonmagnetic 99.43 2.20 96.2
Calculated. Feed 100.0 2.27 100.0
Heat & HZ Magnetic 8.5 10.9 39.8
.. Nonmagnetic 91.5 1.53 60.2
Calculated Feed 100.0 2.33 100.0
Heat & Hz blank Magnetic 0.78 11.4 4.1
Nonmagnetic 99.22 2.11 95.9
Calculated Feed 100.0 2.18 100.0
None Magnetic 5.1 9.73 22.7
(heated to 400° C. Nonmagnetic 94.9 1.79 77.3
and
ferrocene) Calculated Feed 100.0 2.20 100.0
None Magnetic 0.48 10.2 2.5
(heated to 400° C.) Nonmagnetic 99.52 1.99 97.5
Calculated Feed 100.0 2.03 100.0
55
Weight Grade Zinc
Pretreatment Product (%) (%) Distr.
Steam Magnetic 8.4 5.60 25.6
Nonmagnetic 91.6 1.49 74.4
Calculated Feed 100.0 1.84 100.0
Steam blank Magnetic 0.44 10.2 2.7
Nonmagnetic 99.56 1.65 97.3
Calculated Feed 100.0 1.69 100.0
Heat & NZ Magnetic 0.86 15.8 6.9
Nonmagnetic 99.14 1.85 93.1
Calculated Feed 100.0 1.97 100.0
Heat & NZ blank Magnetic 0.41 10.9 2.9
Nonmagnetic 99.59 1.53 97.1
Calculated Feed 100.0 1.57 100.0
None Magnetic 4.1 8.59 21.5
(heated to 400° C; Nonmagnetic 95.9 1.34 78.5
and
rerrocene) Calculated Feed 100.0 1.63 100.0
None Magnetic 0.49 6.19 1.8
(heated to 400° C.) Nonmagnetic 99.51 1.63 98.2
EXAMPLE 9
Samples of different minerals were made into synthetic
ores as indicated in Example 1. Each of these
samples was subjected to a pretreatment and thereafter
treated with 16 kilograms of vaporized ferric acetylac-
60 etonate per metric ton of sample at a temperature of
2700 C. for 30 minutes. The pretreatments were conducted
in the same manner as described in previous
examples. For comparative purposes, additional samples
of the same type of ores were subjected to just the
65 pretreatment. Also, two samples of each of these ores
were given no. pretreatment. One was subjected to the
ferrocene treatment and the other was only heated to
2700 C. All of the samples were subjected to a magnetic
4,289,529
15
separation process. The results of these
samples are given below in Table 9.
TABLE 9
comparative
16
exception of time and temperature variations. The temperature
and time of the pretreatment are set forth in
Weight Grade Metal
Mineral Pretreatment Product (%) (%) Metal Distr.
Galena Steam Magnetic 1.2 8.88 Pb 4.8
Nonmagnetic 98.8 2.14 Pb 95.2
Calculated Feed 100.0 2.22 Pb 100.0
Galena Steam blank Magnetic 0.48 17.2 Pb 3.3
Nonmagnetic 99.52 2.42 Pb 96.7
Calculated Feed 100.0 2.49 Pb 100.0
Galena Heat & Nz Magnetic 0.88 6.59 Pb 2.7
Nonmagnetic 99.12 2.13 Pb 97.3
Calculated Feed 100.0 2.17 Pb 100.0
Galena Heat & Nz blank Magnetic 0.66 6.51 Pb 1.9
Nonmagnetic 99.34 2.24 Pb 98.1
Calculated Feed 100.0 2.27 Pb 100.0
Galena Heat & Hz Magnetic 2.1 5.02 Pb 4.8
Nonmagnetic 97.9 2.15 Pb 95.2
Calculated Feed 100.0 2.21 Pb 100.0
Galena Heat & Hz blank Magnetic 0.78 11.4 Pb 4.1
Nonmagnetic 99.22 2.11 Pb 95.9
Calculated Feed 100.0 2.18 Pb 100.0
Galena None Magnetic 4.5 4.11 Pb 9.4
(acetylacetonate Nonmagnetic 95.5 1.86 Pb 90.6
at 270· C.) Calculated Feed 100.0 1.96 Pb 100.0
Galena None Magnetic 0.52 6.93 Pb 1.9
(heated at 270· C.) Nonmagnetic 99.48 1.86 Pb 98.1
Calculated Feed 100.0 1.89 Pb 100.0
Sphalerite Heat & Nz Magnetic 4.8 7.08 Zn 16.9
Nonmagnetic 95.2 1.75 Zn 83.1
Calculated Feed 100.0 2.01 Zn 100.0
Sphalerite Heat & Nz blank Magnetic 0.41 10.9 Zn 2.9
Nonmagnetic 99.59 1.53 Zn 97.1
Calculated Feed 100.0 1.57 Zn 100.0
Sphalerite None Magnetic 5.1 5.63 Zn 16.8
(acetylacetonate Nonmagnetic 94.9 1.52 Zn 83.2
at 270· C.) Calculated Feed 100.0 1.73 Zn 100.0
Sphalerite None Magnetic 0.54 10.2 Zn 3.1
(heated to 270· C.) Nonmagnetic 99.46 1.72 Zn 96.9
Calculated Feed 100.0 1.77 Zn 100.0
EXAMPLE 10
Table 10. For comparative purposes, samples were
subjected just to the pretreatment, receiving no iron
Samples of sphalerite were made into 3 percent syn- carbonyl treatment. Additionally, two samples received
thetic ores as indicated in Example 1. Each of these 40 no pretreatment with one being subjected to the iron
samples was subjected toa pretreatment of heat and carbonyl treatment and the other merely being heated
hydrogen gas and thereafter treated with 8 kilograms of to a temperature of 135° C. All of the samples were
iron pentacarbony! per metric ton of sample for 30 subjected to a wet magnetic separation process. Analyminutes
at a temperature of 135° C. The pretreatment ses of the products thus obtained are presented below in
was carried out as described in Example 3 with the 45 Table 10.
TABLE 10
Pretreatment
Fe(CO)s Temperature Time Weight Grade Zinc
Treatment rC.) (minutes) Product (%) (%) Distr.
Yes 400 15 Magnetic 6.0 28.6 59.9
Nonmagnetic 94.0 1.22 40.1
Calculated Feed 100.0 2.86 100.0
No 400 15 Magnetic 0.94 7.76 3.9
Nonmagnetic 99.06 1.83 96.1
Calculated Feed 100.0 1.89 100.0
Yes 400 90 Magnetic 66.7 2.00 97.4
Nonmagnetic 33.3 0.108 2.6
Calculated Feed 100.0 1.37 100.0
No 400 90 Magnetic 1.6 5.90 4.9
Nonmagnetic 98.4 1.85 95.1
Calculated Feed 100.0 1.92 100.0
Yes 150 15 Magnetic 13.2 12.7 93.1
Nonmagnetic 86.8 0.143 6.9
Calculated Feed 100.0 1.80 100.0
No 150 15 Magnetic 0.73 14.8 6.0
Nonmagnetic 99.27 1.71 94.0
Calculated Feed 100.0 1.81 100.0
Yes 150 90 Magnetic 30.4 5.28 88.2
Nonmagnetic 69.6 0.308 Il.a
Calculated Feed 100.0 1.82 100.0
No 150 90 Magnetic 0.44 8.58 2.1
4,289,529
17 18
TABLE 10-continued
Pretreatment
Fe(COls Temperature Time Weight Grade Zinc
Treatment ('C,) (minutes) Product (%) (%) Distr.
Nonmagnetic 99.56 1.74 97.9
Calculated Feed 100.0 1.77 100.0
Yes none none Magnetic 36.5 3.50 70.5
Nonmagnetic 63.5 0.842 29.5
Calculated Feed 100.0 1.81 100.0
No (heated none none Magnetic 0.37 12.9 2.7
to 135' C.) Nonmagnetic 99.63 1.71 97.3
Calculated Feed 100.0 1.75 100.0
What is claimed is:
1. In a process for the beneficiation of a sulfide ore
from gangue, excluding coal, wherein the ore is treated 15
with a metal containing compound under conditions
which cause the metal containing compound to react
substantially at the surface ofthe metal sulfide particles
to the substantial exclusion of the gangue particles so as
to alter the surface characteristics of the metal sulfide 20
values thereby causing a selective enhancement of the
magnetic susceptibility of one or more metal sulfide
values of the ore to the exclusion of the gangue iiI order
to permit a physical separation between the metal sulfide
values and the gangue, the improvement compris- 25
ing:
treating the ore with heat prior to its treatment with
the metal containing compound.
2. The process of claim 1 wherein the heat pretreatment
is conducted at a temperature of at least about 80· 30
Co
3. The process of claim 2 wherein the heat pretreatment
is conducted in the presence of a gas selected from
the group consisting of steaJ:Il, nitrogen, hydrogen, carbon
monoxide, carbon dioxide, ammonia, hydrogen 35
sulfide, sulfur dioxide, methane, air, ethane,· propane,
butane and other hydrocarbons in the gaseous state at
the pretreatment temperature.
4. Theprocess of claim 3 wherein the gas is employed
in an amount of at least about 2 cubic meters per hour 40
per metric ton of sulfide ore being treated.
5. The process of claim 3 wherein the gas is steam at
a temperature of at least 100· C. and employed in an
amount of from about 1 weight percent to about 50
weight percent water, based on the weight of the metal 45
sulfide ore.
6. The process of claim 2 or claim 3 wherein the
treatment of the ore with the metal containing compound
is conducted at a temperature within a range of
125· C. less than the general decomposition temperature 50
of the metal ccntaining compound in a specific system
for the ore being treated.
7. The process of claim 6 wherein the metal containing
compound is employed in an amount of from about
0.1 to 100 kilograms per metric ton of ore. 55
8. In a process for the beneficiation of a metal sulfidt::
ore from gangue, excluding coal, wherein the ore is
treated with from about 0.1 to about 100 kilograms of
metal containing compound per metric ton of ore at a
temperature within a range of 125· C. less than the 60
general decomposition temperature of the metal containing
compound in a specific system for the ore being
treated for a period of time of from about 0.05 to about
4 hours to cause the metal containing compound to
react substantially at the surface of the metal sulfide 65
particles to the substantial exclusion ofthe gangue particles
so as to alter the surface characteristics of the metal
sulfide values thereby causing a selective enhancement
of the magnetic susceptibility of one or more. metal
sulfide values contained in the ore to the exclusion of
the gangue in order to permit a physical separation, the
improvement comprising:
the treatment of the· ore with heat prior to treating it
with the metal containing compound.
9. The process ofclaim 1 or claim 8 wherein the metal
containing compound is an iron containing compound.
10. The process of claim 9 wherein the iron containing
compound is selected from the group consisting of
ferrous chloride, ferric chloride, ferrocene, ferrocene
derivatives, ferric acetylacetonate, and ferricacetylacetonate
derivatives.
11. The process of claim 1 or claim 8 wherein the
metal containing compound is a carbonyl. .
12. The process. of claim 11 wherein the carbonyl is
selected from the group consisting of iron, cobalt, and
nickel.
i3. The. process of claim 12 wherein the carbonyl
comprises an iron carbonyl.
14.. The process of claim 9 .wherein the ore is pretreated
toa temperature of at least about 80· C. for a
time period of at least about0.1 hours.
15. The process of claim 14 wherein the ore. is pretreated
to a temperature of from about 125· C. to about
450· C. for a time period offrom about 0.20 t6 about 4
hours.
16. The process ofclaim 14 wherein the heat pretreatment
is conducted in the presence of a gas selected from
the group consisting of steam, nitrogen,hydrogen, carbon
monoxide, carbon dioxide, ammonia, hydrogen
sulfide, sulfur dioxide, methane, air, ethane, propane,
butane, and other hydrocarbon compounds in the gase~
ous state at the pretreatment temperature.
17. The process of claim 16 wherein the gas is employed
in an amount of at least about 12 cubic meters
per hour per metric ton of ore being processed.
18. The process of claim 16 wherein the gas is steam
at a temperature of from about 150·. C. to about 450' C.
and comprised of from about 5 weight percent to about
30 weight percent· water, based on the weight of the
metal sulfide ore.
19. The process of claim 17 wherein the gas is nitrogen.
20. The process of claim 17 wherein the gas is hydrogen.
21. The process of claim 17 wherein the gas is carbon
monoxide.
22. The process of claim 15 wherein the metal containingcompound
is an iron carbonyl and the treatment
of the ore with the iron carbonyl is carried out at a
temperature within a range of 15· C. less than the general
decomposition temperature. of the iron carbonyl in
the specific system for the ore being treated.
4,289,529
20
selected from the group consisting of steam, nitrogen,
hydrogen, and carbon monoxide.
44. The process of claim 43 wherein the ore is galena
and the gas is selected from the group consisting of
steam, nitrogen and hydrogen.
45. The process of claim 43 wherein the ore is sphalerite
and the gas is nitrogen.
46. In a process for the beneficiation of a sulfide ore
from gangue, excluding coal, wherein the ore is treated
with an iron carbonyl compound under conditions
which cause the iron carbonyl compound to react substantially
at the surface of the metal sulfide particles to
the substantial exclusion of the gangue particles so as to
alter the surface characteristics of the metal sulfide
15 values thereby causing a selective enhancement of the
magnetic susceptibility of one or more metal sulfide
values of the ore to the exclusion of the gangue in order
to permit a separation between the metal sulfide values
and the gangue, the improvement comprising:
treating the ore with heat prior to its treatment with
the iron carbonyl compound.
47. The process of claim 46 wherein the heat pretreatment
is conducted at a temperature of at least 800 C.
48. The process of claim 47 wherein the sulfide ore is
selected from the group consisting of galena, sphalerite,
molybdenite, stibnite, smaltite, chalcopyrite, orpiment,
cinnabar, bornite, arsenopyrite, realgar, pentlandite and
tetrahedrite.
49. The process of claim 47 or claim 48 wherein the
heat pretreatment is conducted in the presence of a gas
selected from the group consisting of steam, nitrogen,
hydrogen, carbon monoxide, carbon dioxide, ammonia,
hydrogen sulfide, sulfur dioxide, methane, air, ethane,
propane, butane, and other hydrocarbons in the gaseous
state at the pretreatment temperature.
50. The process of claim 49 wherein the pretreatment
is conducted at a temperature of from about 1750 C. to
about 2500 C.
51. The process of claim 49 wherein the gas is steam
at a temperature offrom about 1500 C. to about 4500 C.
and comprises from about 10 weight percent to about 25
weight percent water, based on the weight of the sulfide
ore being treated.
52. The process of claim 50 wherein the gas is hydrogen
employed in an amount of at least 120 cubic meters
per hour per metric ton of ore being treated.
53. The process of claim 50 wherein the gas is carbon
monoxide employed in an amount of at least about 120
cubic meters per hour per metric ton of ore being
treated.
54. The process of claim 50 wherein the gas is nitrogen
employed in an amount of at least about 120 cubic
meters per hour per metric ton of ore being treated.
55. The process of claim 50 wherein the iron carbonyl
is iron pentacarbonyl employed in an amount of from
about 2 to about 20 kilograms per metric ton of ore at a
temperature of 150 C. less than the general decomposition
temperature of the iron pentacarbonyl in a specific
system for the ore being treated for a time of from about
0.05 to about 4 hours.
56. The process of claim 11 wherein the ore is pretreated
to a temperature of at least about 800 C. fora
time period of at least about 0.1 hours.
57. The process of claim 56 wherein the ore is pretreated
to a temperature of from about 1250 C. to about
4500 C. for a time period of from about 0.20 to about 4
hours.
19
23. The process of claim 22 wherein the ore is treated
with heat and a gas selected from the group consisting
of steam, nitrogen, hydrogen, and carbon monoxide.
24. The process of claim 23 wherein the metal sulfide
ore is selected from the group consisting of galena, 5
sphalerite, molybdenite, stibnite, smaltite, chalcopyrite,
orpiment, cinnabar, bornite, arsenopyrite, realgar, pentlandite
and tetrahedrite.
25. The process of claim 24 wherein the ore is galena.
26. The process of claim 24 wherein the ore is molyb- 10
denite.
27. The process of claim 24 wherein the ore is stibnite.
28. The process of claim 24 wherein the ore is smaltite.
29. The process of claim 24 wherein the ore is chalcopyrite.
30. The process of claim 24 wherein the ore is orpiment.
31. The process of claim 24 wherein the ore is cinna- 20
bar.
32. The process of claim 24 wherein the ore is bornite.
33. The process of claim 24 wherein the ore is arsenopyrite.
34. The process of claim 24 wherein the ore is realgar. 25
35. The process of claim 24 wherein the ore is pentlandite.
36. The process of claim 24 wherein the ore is tetrahedrite.
37. The process of claim 23 wherein the gas is steam. 30
38. In a process for the beneficiation of a metal sulfide
ore from gangue, excluding coal, wherein the metal
sulfide ore is selected from a group consisting of galena,
molybdenite, sphalerite, bornite, cinnabar, arsenopyrite,
smaltite, chalcopyrite, orpiment, realgar, pentlandite, 35
stibnite, and tetrahedrite and wherein the ore is treated
with from about 2 to about 20 kilograms of an iron
containing compound per metric ton of ore at a temperature
within a range of 1250 C. less than the general
decomposition temperature of the iron containing com- 40
pound in a specific system for the ore being treated to
cause the iron containing compound to react substantially
at the surface of the metal sulfide particles to the
substantial exclusion of the gangue particles so as to
alter the surface characteristics of the metal sulfide 45
values thereby causing a selective enhancement of the
magnetic susceptibility of one or more metal sulfide
values contained in the ore to the exclusion of the
gangue in order to permit their magnetic separation, the
improvement for the ore in a specific system compris- 50
ing:
heating the ore to a temperature of at least about 800
C. prior to its treatment with the iron containing
compound.
39. The process of claim 38 wherein the iron contain- 55
ing compound is ferrocene and the heat pretreatment is
conducted in the presence of a gas selected from the
group consisting of steam, nitrogen, hydrogen, and
carbon monoxide.
40. The process of claim 39 wherein the ore is galena. 60
41. The process of claim 39 wherein the ore is sphalerite
and the gas is selected from the group consisting of
steam and nitrogen.
42. The process of claim 39 wherein the ore is molybdenite
and the gas is selected from the group consisting 65
of steam, hydrogen, and carbon monoxide.
43. The process of claim 38 wherein the iron containing
compound is ferric acetylacetonate and the gas is
• • • • •
4,289,529
21 22
58. The processorclaimS6 wherein the heat pretreat- 60. The process or claim 59 wherein the 'gas is steam
ment is conducted in the presence oh gaS selected from at a temperatureof from about ISO· C. to about 450· C.
. . '.'. and comprised of from about 5 weight percent to about
the group consisting ofsteam, nitrog~n, hydrogen, car- 30 weight percent water, based on the weightofthe
. boil monoxide, carbon dioxide, ammonia, hydrogen 5 metal sulfide ore.
sulfide, sulfur dioxide, methane, air, ethane, propane, 61. The process of claim 59 wherein the gas is nitrobutane
and other hydrocarbon compounds in the gase- gen.
.' ous state at the pretreatment. temperat\lre. 62. The process of claim 59 wherein the gas is hydrogen.
59. The process or claim 58 wherein the gas is em-· 10 . 63. The process of claim 59 wherein the gas is carbon'
plc;>yed in an amount orat least 12 cubic meters per hour .. monoxide; .
. per metric ton of ore being processed.
15
20
25
30
35
40
45
50
55
60
65