United States Patent [19]
Kindig et aI.
[II]
[45]
4,257,881
Mar. 24, 1981
[56] References Cited
U.S. PATENT DOCUMENTS
[54] PROCESS FOR BENEFICIATING OXIDE
ORES
[75] Inventors: James K. Kindig, Arvada; Ronald L.
Turner, Golden, both of Colo.
[73] Assignee: Hazen Research, Inc., Golden, Colo.
[21] App!. No.: 921,583
[22] Filed: Jul. 3, 1978
Related U.S. Application Data
[63] Continuation-in-part ofSer. No. 868,416, Jan. 10, 1978,
abandoned, which is a continuation-in-part of Ser. No.
658,258, Feb. 17, 1976, abandoned.
[51] Int. Cl.2 C22B 1/00
[52] U.S. Cl 75/1 R; 209/214;
209/8; 427/252; 427/253; 427/132
[58] Field of Search 75/1 R, I T, 21, 28,
75/62, 72, 77, 82, 87, Ill, 122; 423/231, 138,
25;209/212,213,214,8;427/47,252,254,253,
255, 132
60 Claims, No Drawings
Frysinger et al. 75/119
O'Neill et aI 75/0.5
mis et al. 75/112
Krivisky et al. 423/25
Sato 423/25
Kindig et al. 44/1 R
Glaeser 75/1 T
McEway et al. 423/417
Kindig et al. 44/1 R
ABSTRACf
5/1966
6/1967
9/1969
1/1920
6/1972
2/1976
8/1976
11/1977
7/1978
3,252,791
3,323,903
3,466,167
3,490,899
3,669,644
3,938,966
3,977,862
4,056,386
4,098,584
One or more mineral values of metal oxide ores selected
from the group consisting of bauxite, taconite, apatite,
titanium oxides and the metal oxides of Groups, IIIB,
IVB, VB VIB, VIIB, VIIIB, IB, lIB and IVA are beneficiated
by treating the 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 physical
separation between the values and gangue.
[57]
FOREIGN PATENT DOCUMENTS
179095 7/1954 Austria 75/112
119156 8/1959 U.S.S.R 208/212
119179 8/1959 U.S.S.R , 75/1 T
Primary Examiner-L. Dewayne Rutledge
Assistant Examiner-Michael L. Lewis
Attorney, Agent, or Firm-Sheridan, Ross, Fields &
Mcintosh
Ethenington 75/1 R
Gaus 75/1 T
Dean et al. 423/25
Drummond 427/252
Altmann 75/0.5
Queneau et al. 75/0.5
Queneau 474/217
2/1913
1/1931
10/1938
10/1943
9/1952
7/1960
11/1965
1,053,486
1,789,813
2,132,404
2,332,309
2,612,440
2,944,883
3,220,875
5
2
to selectively enhance the magnetic susceptibility of
various mineral values contained within the ore. The
treated mixture can then be subjected to a physical
separation process to produce a beneficiated product.
"Enhancing the magnetic susceptibility" of the ore as
used herein is intended to be defined in accordance with
the following discussion. Every compound ofany type
has a specifically defined magnetic susceptibility, which
refers to the overall attraction of the compound to a
10 magnetic force. An alteration of the surface magnetic
characteristics will alter the magnetic susceptibility.
Both the metal containing compound treatment and the
metal and gas cotreatment of the inventive process alter
the surface characteristics of the ore particles in order
to enhance the magnetic susceptibility of the particles.
It is to be understood that the magnetic susceptibility of
the particle is not actually changed, but the particle
itself is changed, at least at its surface, resulting in a
particle possessing a greater magnetic susceptibility
than the original particle. For convenience of discussion,
this alteration is termed herein as "enhancing the
magnetic susceptibility" of the particle or ore itself.
The metal oxide minerals which are capable of undergoing
a selective magnetic enhancement in accordance
with the process include the metal oxides of Groups
II1B, IVB, VB, VIB, VIIB, VIIIB, IB, lIB and IVA,
the titanium oxides of Group IVB, aluminum hydrate,
i.e. bauxite, of Group IlIA, taconite and apatite. It is
recognized that taconite and apatite are generally classified
as a type of silicate and phosphate, respectively,
and it is further recognized that apatite does not contain
elements generally classified as metals (other than calcium).
However, for the purposes of this inventive pro-
35 cess they are classified as metal oxides. The preferred
oxide minerals include bauxite, rutile, taconite, apatite,
pyrochlore, uraninite, cuprite, cassiterite, carnotite,
scheelite and hematite.
The gangue minerals from which the metal oxide ores
can be separated include those minerals which do not
undergo a sufficient magnetic susceptibility enhancement
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.
In those ores which contain naturally relatively
strongly magnetic constituents, such as magnetite, the
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
or cotreatment with a metal containing compound
and the reducing gas.
Prior to either of the treatments, the ore must be
ground to liberate the metal oxide particles from the
gangue particles, if the respective components do not
already exist in this liberated state. The ore may be
crushed finer than necessary to achieve liberation, but
this is not generally economically possible. It is gener-
60 ally satisfactory to crush the ore to minus 14 mesh,
although some ores require fmer mesh sizes.
Numerous metal containing compounds are capable
of enhancing the magnetic susceptibility of these metal
oxides 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
4,257,881
1
SUMMARY OF THE INVENTION
DESCRIPTION OF THE PREFERRED
EMBODIMENTS
BACKGROUND OF THE INVENTION
PROCESS FOR BENEFICIATING OXIDE ORES
The process of the present invention is particularly
useful for concentrating metal oxide minerals. The pro- 65
cess employs the treatment of the ore with a metal containing
compound or the cotreatment of the ore with a
metal containing compound and a reducing gas in order
The process of the present invention entails treating a
metal oxide ore selected from the group consisting of 45
bauxite, taconite, apatite, titanium oxides and the metal
oxides of Groups IIIB, IVB, VB, VIB, VIIB, VIIIB,
IB, lIB and IVA with a metal containing compound
under processing· conditions such that the magnetic
susceptibility of the ore is selectively enhanced to the 50
exclusion of the gangue. The affected ore values may
then be magnetically separated from the less magnetic
constituents.
Additionally, an improved beneficiation of many of
these ores can be obtained by cotreating the ore with a 55
metal containing compound and a reducing gas under
processing conditions such as to selectively enhance the
magnetic susceptibility of the mineral values to the
exclusion of the gangue in order to permit a physical
separation of the values from the gangue.
1. Field of the Invention
This invention relates to a means for treating ores to
separate the mineral values from gangue material by 15
selectively enhancing the magnetic susceptibility of the
mineral values so that they may be magnetically removed
from the gangue.
2. Description of the Prior Art
As is well known, mining operations in the past for 20
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
grade ores is increasing. The processing of these leaner
ores consumes large amounts of time, labor, reagents, 25
power and water with conventional processing.
In addition to the increased expense associated with
the extraction of these metals from low grade ores,
proposed processes for separation of certain of the sulfide
ores are technically very difficult and involve elab- 30
orate 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
mineral recovery, while theoretically possible, is economically
unfeasible.
Accordingly, it is a principal object of this invention
to provide a method of treating metal oxide ores which
separates the mineral values from gangue material by
selectively enhancing the magnetic susceptibility of one
or more mineral values in order that they may be mag- 40
netically removed from the gangue.
CROSS REFERENCETO RELATED
APPLICATIONS
This application is a continuation-in-part of copending
application Ser.No. 868,416 filed Jan. 10, 1978, now
abandoned, which is a continuation-in-part of now
abandoned applicationSer. No: 658,258 filed Feb. 17,
1976, now abandoned.
4,257,881
4
remaining essentially unreactive, or much less reactive,
at the surface of the gangue particles. The temperature
of the reaction is a critical parameter, and dependent
primarily upon the particular compound and the particular
ore, and also the cotreating gas, in tl,J.e case of the
cotreatment process. The preferred temperature can be
determined by heating a sample of the specific iron
containing compound and the specific ore together until
the decomposition reaction occurs. Suitable results generally
occur over a given temperature range for each
system. Generally, temperatures above the range cause
non-selective decomposition while temperatures below
the range are insufficient for the reaction to occur.
While as indicated above, techniques other than
vapor injection methods may be employed as applicable
depending upon the metal containing compound being
utilized, the following discussion. primarily applies to
vapor injection techniques, specifically iron pentacarbonyl,
as these are generally preferred. Similar considerations,
as can be appreciated, apply to the other described
techniques.
The preferred temperatures when iron pentacarbonyl
is employed as the treating gas are primarily dependent
upon the ore being treated and in the case ofthe cotreatment
process, the cotreatment gas being utilized. It is
generally preferred to select a temperature which is
within a range of 125° C., 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 decomposition temperature is intended
to mean the temperature at which the iron carbonyl
decomposes into iron and carbon monoxide in an
indiscriminate fashion, causing a magnetic enhancement
of the gangue as well as the metal oxide. The "specific
35 system" is intended to include all components and parameters,
other· than, of course, temperature, of the
precise treatment, as the general decomposition temperature
generally varies with different components· and-
/or different parameters. This decomposition temperature
range can be readily determined by analytical
methods, and often a trial and error approach is preferred
to determine the precise temperature range for
each specific system.
The amoUnt of the metal containing compound used
and the time of treatment can be varied to maximize the
selective enhancement treatment. With respect to iron
carbonyl the preferred amount employed is from about
0.1 to about 100 kilograms per metric ton of feed, more
preferably from about I to about 50 kilograms per metric
ton of feed, and most preferably from about 2 to 20
kilograms per metric ton of feed. The reaction is generally
conducted for a period oftime offrom about 0.05 to
about 4 hours, more preferably from about 0.15 to about
2 hours, and most preferably from about 0.25 to about I
hour. .
The particular process of the invention concerns
treating the ore with a metal containing compound.
Another embodiment of this invention entails cotreating
the ore with a metal containing compound while
simultaneously treating the ore with a reducing gas.
Preferred gases include those selected from the group
consisting of hydrogen, carbon monoxide, ammonia,
and lower hydrocarbons in the range of about CI to Cg,
particularly including methane, ethane, ethylene, propane,
propylene, butane and butylene, as well as other
similar reducing gases. These gases in and ofthemselves
have no appreciable effect upon the magnetic susceptibility
of the mineral values; however, they can signifi-
3
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 as a component in the 5
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
which can be dissolved and/or "dusted" and brought
into contact with the mineral value contained within the 10
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 15
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. 20
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, 25
suspensions and emulsions. These compounds must be
such as to provide sufficient metal to contact the surface
ofthe mineral value. Suitable carrier liquids include, for
example, acetone, petroleum, ether, naphtha, hexane,
benzene and water; but this, of course, is d6pendent 30
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 40
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 lOO-mesh, and most preferably
smaller than about 4OO-mesh. Compounds within this 45
grouping include ferrocene and its derivatives, iron salts
of organic acids, and beta-diketone compounds of iron.
Specific examples include ferrous formate, I,l'-diacetyl
ferrocene, and I,I'-dihydroxymethyl ferrocene.
Various inorganic compounds are also capable of 50
producing an- enhanced magnetic susceptibility. Preferred
inorganic compounds include ferrous chloride,
ferric chloride and the metal carbonyls, including, for
example, iron, nickel, cobalt, molybdenum, tungsten
and chromium carbonyls and derivatives of these com- 55
pounds. Iron carbonyl is a preferred carbonyl for imparting
this magnetic susceptibility, particularly iron
pentacarbonyl, iron dodecacarbonyl and iron nonacarbony!.
The more preferred metal containing compounds
capable of enhancing the magnetic susceptibil- 60
ity are iron pentacarbonyl, ferrocene, ferric acetylacetonate,
ferrous chloride and ferric chloride, with iron
pentacarbonyl being the most preferred.
The process is applied by contacting the iron containing
compound with the ore at a temperature wherein 65
the iron containing compound selectively decomposes
or otherwise reacts at the surface of the metal oxide
particles to alter their surface characteristics, while
TABLEl
EXAMPLE 2
Weight Iron Iron
Percent Of Analysis. Distribution,
Sample Percent Percent
Concentrate 34.3 5.77 58.6
(Magnetic)
Gangue 65.7 2.13 41.4
(Nonmagnetic)
Feed 100.0 3.38 100.0
6
EXAMPLE 1
A sample of taconite from the Mesabi range was
prepared by crushing to minus 14 by 200-mesh, and
passing it through a Stearns cross-belt magnetic separator
to remove any naturally magnetic material. Twentyseven
grams of the non-magnetic fraction thus obtained
were placed in a small glass rotating reactor and heated
to 1900 -1950 C. while iron carbonyl was injected into
the chamber during a 60-minute interval, providing a
total of 4 kilograms of iron carbonyl per metric ton of
taconite ore. The treated product was again passed
through the magnetic separll-tor, forming a magnetic
fraction and a nonmagnetic fraction.
The results of the above test are set forth in the following
table:
Samples of different minerals were ground to 65mesh
and mixed with minus 65-mesh silica sand to produce
3% synthetic ores with the exception of carnotite
which is a 5% ore. Each sample was treated for a period
of 30 minutes with 8 kilograms of iron carbonyl per
metric ton of ore. The iron carbonyl was injected as a
vapor during the first 10 minutes of this 30 minute treatment.
The temperature of the treatment varied for the
different minerals. Additionally, for each sample treated
with iron carbonyl another sample was run under the'
identical conditions with the omission of the iron carbonyl
in order to obtain comparative data. All of the
samples with the exception of hematite were subjected
to a wet magnetic separation process which utilized a
current of 2 amperes in the magnetic coils. The magnetic
separation of hematite utilized a current of 0.2
45 amperes in the magnetic coils. Data are presented in
Table 2 (Figures contained within brackets in Table 2
denote calculated amounts).
4,257,881
5
candy improve the results obtained over the metal containing
compound treatments alone.
The metal containing compound and the gas may be
introduced into the reaction chamber together or simultaneously
from different inlets, as long as.the reducing 5
gas is available to the metal containing compound during
the treatment.
The type and amount of gas will depend to some
extent upon the metal containing compound being used.
Generally, the gas will be employed at a concentration 10
of preferably at least about 1 percent, more preferably
at least about 10 percent and most preferably about 100
percent of the reactor atmosphere.
Neither of the processes of this invention are especially
useful in beneficiating oxide ores which are 15
highly naturally magnetic since such ores can be beneficiated
by subjecting them to a magnetic separation process
or first heating them before the magnetic process.
An example of such an ore is pyrolusite.
After the feed mixture containing the metal oxide 20
values has been treated with a metal containing compound,
it can then be subjected to a physical separation
process to effect the separation of the treated metal
oxides from the gangue. Any of many commercially
available magnetic separators can be used to remove 25
these values from the gangue. For example, low or
medium intensity separations can be made with a permanent
magnetic drum separator, electromagnetic
drum separators, induced roll separators or other configurations
known to those skilled in the art. Since most 30
oxides are liberated at a mesh size of 65 mesh or finer, a
wet magnetic separation process is more effective.
Thus, high intensity, high gradient wet magnetic separators
are preferred. Also, electrostatic techniques may
be employed as the primary separation means, or in 35
addition to the magnetic separation means. The selective
change in surface characteristics changes the electrical
conductivity of the particle in analogous fashion
to changing the particle'smagnetic characteristics. Additionally,
due to the fact that the oxide surface charac- 40
teristics have been altered, the oxides are often more
amenable to processes such as flotation and chemical
leaching.
TABLE 2
Fe(CO)s METAL OXIDE
DOSAGE WEIGHT GRADE DISTRIBUTION
MINERAL TEMP. ·C. (kg.lm.ton) PRODUCT (%) (%) METAL (%)
Pyrochlore 124 8 Magnetic 7.7 .61 Cb 31.6
Nonmagnetic 92.3 .11 Cb 68.4
Calculated feed 100.0 .149 Cb 100.0
Pyrochlore 124 0 Magnetic .90 2.0 Cb 16.2
Nonmagnetic 99.10 .094 Cb 83.8
Calculated feed 100.0 .111 Cb 100.0
Uraninite 130 Magnetic .95 .087 U 89.2
Nonmagnetic 99.05 (.0001) U 10.8
Calculated feed 100.0 (.00093) U 100.0
Uraninite 130 0 Magnetic .59 .10 U 62.1
Nonmagnetic 99.41 (.00036) U 37.9
Calculated feed 100.0 (.0095) U 100.0
Cuprite 125 Magnetic 2.1 .165 Cu 46.9
Nonmagnetic 77.9 .004 Cu 53.1
Calculated feed 100.0 .0074 Cu 100.0
Cuprite 125 0 Magnetic .54 .417 Cu 31.2
Nonmagnetic 99.46 .005 Cu 68.8
Calculated feed 100.0 .0073 Cu 100.0
Cassiterite 128 Magnetic 3.5 4.83 Sn 14.9
Nonmagnetic 96.5 .998 Sn 85.1
4,257,881
7 8
TABLE 2-continued
Fe(CO)s METALOXlDE
DOSAGE WEIGHT GRADE DISTRIBUTION
MINERAL TEMP. 'c. (kg./m.ton) PRODUCT (%) (%) METAL (%)
Calculated feed 100.0 1.13 Sn 100.0
Cassiterite 128 0 Magnetic .65 23.6 Sn 10.8
Nonmagnetic 99.35 1.25 Sn 89.2
Calculated feed 100.0 1.39 Sn 100.0
Rutile 130 Magnetic 26.8 4.40 Ti 72.9
Nonmagnetic 73.2 0.06 Ti 27.1
Calculated feed 100.0 1.62 Ti 100.0
Rutile 130 0 Magnetic .96 29.1 Ti 16.4
Nonmagnetic 99.04 1.44 Ti 83.6
Calculated feed 100.0 1.71 Ti 100.0
Bauxite 150 Magnetic 18.3 2.87 AI 84.0
Nonmagnetic 81.7 .122 Al 16.0
Calculated feed 100.0 .625 AI 100.0
Bauxite 144 Magnetic 3.3 20.1 AI 98.0
Nonmagnetic 96.7 .014 Al 2.0
Calculated feed 100.0 .677 Al 100.0
Bauxite 144 0 Magnetic .81 17.0 Al 18.7
Nonmagnetic 99.19 .605 AI 81.3
Calculated feed 100.0 .738 AI 100.0
Carnotite 145 Magnetic 1.4 .731 U30 8 35.3
Nonmagnetic 98.6 .019 U30 8 64.7
Calculated feed 100.0 .029 U30 8 100.0
Carnotite 145 0 Magnetic .67 .297 U308 6.7
Nonmagnetic 99.33 .028 U308 93.3
Calculated feed 100.0 .030 U30 8 100.0
Scheelite 135 Magnetic 27.4 2.85 W 58.6
Nonmagnetic 72.6 .76 W 41.4
Calculated feed 100.0 1.33 W 100.0
Scheelite 135 0 Magnetic 2.1 2.44 W 4.1
Nonmagnetic 97.9 1.23 W 95.9
Calculated feed 100.0 1.25 W 100.0
Hematite 125 Magnetic 1.14 36.2 Fe 34.0
Nonmagnetic 98,86 .81 Fe 66.0
Calculated feed 100.0 1.21 Fe 100.0
Hematite 125 0 Magnetic .10 22.9 Fe 3.0
Nonmagnetic 99.90 .73 Fe 97.0
Calculated feed 100.0 .752 Fe 100.0
Apatite 125 Magnetic 4.9 7.10/4.0/.90 Ca/PIF 36.5/39.9/39.8
Nonmagnetic 95.1 .64/.311.07 CalPlF 63.5/60.1160.2
Calculated feed 100.0 .096/.4911.111 CalPlF 100.0
Apatite 125 0 Magnetic .41 1.95/.34 CalP 0.7/0.7
Nonmagnetic 99.59 1.09/.36 Ca/P 99.3/99.3
Calculated feed 100.0 1.09/.360 CalP 100.0
Apatite 115 Magnetic .57 8.94/4.4/1.10 Ca/P/F 3.7/4.114.1
Nonmagnetic 99.43 1.34/.59/.14 Ca/PIF 96.3/95.9/95.9
Calculated feed 100.0 1.38/.613/.145 Ca/PIF 100.0
EXAMPLE 3
ore sample and then the petroleum ether was evapo-
45 rated off. Thereafter, the material was placed in a reac-
Samples of different minerals were mixed with silica tor and the temperature was raised to 400° C. over a
sand to produce 3% synthetic ores with the exception two-hour period. The remaining samples were treated
of carnotite which is a 5% synthetic ore. Some samples exactly the same with the omission offerrocene in order
were treated with ferrocene which had been dissolved to obtain comparative data. Table 3 shows the camparain
petroleum ether. This ferrocene was mixed with the tive results.
TABLE 3
Ferrocene METALOXlDE
DOSAGE WEIGHT GRADE DISTRIBUTION
MINERAL TEMP 'C. (kg./m.ton) FRACTION (%) (%) METAL (%)
Bauxite 400 16 Magnetic 3.4 14.3 AI 86.3
Nonmagnetic 96.6 .08 AI 13.7
Calculated feed 100.0 .563 AI 100.0
Bauxite 400 0 Magnetic 2.4 17.7 Al 64.5
Nonmagnetic 97.6 .24 AI 35.5
Calculated feed 100.0 .659 AI 100.0
Scheelite 400 16 Magnetic 3.3 1.96 W 15.0
Nonmagnetic 96.7 .38 W 85.0
Calculated feed 100.0 .432 W 100.0
Scheelite 400 0 Magnetic 1.25 1.36 W 3.8
Nonmagnetic 98.75 .43 W 96.2
Calculated feed 100.0 .442 W 100.0
Carnotite 400 16 Magnetic 8.0 .193 U308 52.8
Nonmagnetic 92.0 .015 U308 47.2
Calculated feed 100.0 .029 U308 100.0
Carnotite 400 0 Magnetic 1.07 .410 U308 15.1
Nonmagnetic 98.93 .025 U308 84.9
9
4,257,881
TABLE 3-continued
10
Ferrocene METAL OXIDE
DOSAGE WEIGHT GRADE DISTRIBUTION
MINERAL TEMP 'c. (kg./m.ton) FRACTION (%) (%) METAL (%)
Calculated feed 100.0 .029 U308 100.0
Apatite 400 16 Magnetic 5.1 5.14/2.1/.49 Ca/P/F 27.9/26.1127.3
Nonmagnetic 94.9 .714/.32/.07 Ca/P/F 72.1173.9/72.7
Calculated feed 100.0 .940/.41 V.091 Ca/P/F 100.0
Apatite 400 0 Magnetic .54 1.22 P 1.5
Nonmagnetic 99.46 0.43 P 98.5
Calculated Feed 100.0 0.435 P 100.0
Cuprite 400 16 Magnetic 2.2 36.9 Cu 86.5
Nonmagnetic 97.8 0.130 Cu 13.5
Calculated feed 100.0 0.939 Cu 100.0
Cuprite 400 0 Magnetic 1.52 28.5 Cu 46.8
Nonmagnetic 98.48 0.500 Cu 53.2
Calculated feed 100.0 0.926 Cu 100.0
Uraninite 400 16 Magnetic 12.2 0.030 U308 67.6
Nonmagnetic 87.8 0.002 U308 32.4
Calculated feed 100.0 0.0054 U308 100.0
Uraninite 400 0 Magnetic 1.4 0.100 U308 26.2
Nonmagnetic 98.6 0.004 U308 73.8
Calculated feed 100.0 0.0053 U308 100.0
EXAMPLE 4
Samples of 3% synthetic ores (carnotite is a 5% synthetic
ore) were treated with 16 kilograms of vaporized 25
ferric acetylacetonate per metric ton of ore at a temperature
of 2700 C. for a period of 30 minutes. Samples
identical in composition were subjected to the same
treatment with the omission of the ferric acetylacetonate.
The comparative results are shown in Table 4.
TABLE 4
the reducing gas for 15 minutes at a flow rate such that
one reactor volume of reducing gas was introduced into
the system every 4.3 minutes. This was immediately
followed by treatment with iron carbonyl for 30 minutes
with the iron carbonyl being injected during the
first 10 minutes of treatment. Samples of the same ores
were treated under the same conditions with only the
reducing gas. All of the samples except· hematite were
subjected to a wet magnetic separation process which
Metal Oxide
Temp. Dosage Weight Grade Distribution,
Mineral 'C. (kg./m./ton) Fraction (%) (%) Metal (%)
Bauxite 270 16 Magnetic 2.4 18.9 Al 69.9
Nonmagnetic 97.6 0.20 Al 30.1
Calculated feed 100.0 0.649 Al 100.0
Bauxite 270 0 Magnetic 1.6 24.4 AI 48.0
Nonmagnetic 98.4 0.43 AI 52.0
Calculated feed 100.0 0.814 AI 100.0
Scheelite 270 16 Magnetic 3.1 0.96 W 7.7
Nonmagnetic 96.9 0.37 W 92.3
Calculate<;l feed 100.0 0.389 W 100.0
Scheelite 270 0 Magnetic 1.3 1.09 W 3.3
Nonmagnetic 98.7 0.42 W 96.7
Calculated feed 100.0 0.429 W 100.0
Carnotite 270 16 Magnetic 1.2 0.418 U308 25.3
Nonmagnetic 98.8 0.Ql5 U308 74.7
Calculated feed 100.0 0.020 U308 100.0
Carnotite 270 0 Magnetic 0.97 0.514 U308 21.9
Nonmagnetic 99.03 0.Ql8 U308 78.1
Calculated feed 100.00 0.023 U308 100.0
Apatite 270 16. Magnetic 2.3 2.28/.96/.25 Ca/P/F 6.9/5.8/6.1
Nonmagnetic 97.7 .720/.37/.09 Ca/P/F 93.1194.2/94.9
Calculated feed 100.0 .755/.384/.094 Ca/P/F 100.0
Apatite 270 0 Magnetic 0.34 0.637 P 0.5
Nonmagnetic 99.66 0.427 P 99.5
Calculated feed 100.00 0.428 P 100.00
EXAMPLE 5
Several samples of 3% synthetic ores were cotreated
with 8 kilograms of iron pentacarbonyl per metric ton
of ore and a reducing gas. Each of the cotreatment 60
samples were heated, then the system was purged with
utilized a current of 2.0 amperes in the magnetic coils.
The magnetic separation of hematite was conducted
with a current of 0.2 amperes in the magnetic coils. The
comparative results are shown in Table 5 (Figures given
in brackets in Table 5 denote calculated amounts).
TABLE 5
Fe(CO)s METAL OXIDE
MINERAL DOSAGE WEIGHT GRADE DISTRIBUTION
. (TEMP. 'C) GAS (kg./m.ton) PRODUCT (%) (%) METAL (%)
Bauxite H2 8 Magnetic 16.0 3.62 Al 93.2
(144). Nonmagnetic 84.0 .05 Al 6.8
Calculated feed 100.0 .621 AI 100.0
4,257,881
11 12
TABLE 5-continued
Fe(CO)s METAL OXIDE
MINERAL DOSAGE WEIGHT GRADE DISTRIBUTION
(TEMP. ·C.) GAS (kg./m.ton) PRODUCT (%) (%) METAL (%)
Bauxite Hz 0 Magnetic .94 14.7 AI 21.5
(144) Nonmagnetic 99.06 .51 Al 78.5
Calculated feed 100.0 .643 AI 100.0
Bauxite CO Magnetic 1.35 15.6 AI 37.2
(144) Nonmagnetic [98.65] .36 Al 62.8
Calculated feed 100.0 .566 AI 100.0
Bauxite CO 0 Magnetic 1.04 16.0 Al 24.4
(144) Nonmagnetic 98.96 .52 Al 75.6
Calculated feed 100.0 .681 AI 100.0
Apatite Hz Magnetic 7.2 7.76/3.3 Ca/P 57.6/57.4/
(125) Nonmagnetic 92.8 .443/.19 Ca/P 42.4/42.6/
Calculated feed 100.0 .970/.414 Ca/P 100.0
Apatite Hz 0 Magnetic 0.54 0.72 P 0.9
(125) Nonmagnetic 99.46 0.43 P 99.1
Calculated feed 100.0 0.432 P 100.0
Apatite CO Magnetic 0.18 1.61/.06 Ca/P 0.3/.03
(125) Nonmagnetic 99.82 .960/.37 Ca/P 99.7/99.97
Calculated feed 100.00 .961/.369 Ca/P 100.0
Apatite CO 0 Magnetic 0.47 0.56 P 0.8
(125) Nonmagnetic 99.53 0.308 P 99.2
Calculated feed 100.00 0.309 P 100.0
Scheelite Hz 8 Magnetic 10.4 1.90 W 43.2
(135) Nonmagnetic 87.6 0.29 W 56.8
Calculated feed 100.0 0.458 W 100.0
Scheelite . Hz 0 Magnetic 1.33 1.22 W 4.1
(135) Nonmagnetic 98.67 0.38 W 95.9
Calculated feed 100.00 0.391 W 100.0
Scheelite CO Magnetic 1.3 1.29 W 3.6
(135) Nonmagnetic 98.7 0.46 W 96.4
Calculated feed 100.0 0.471 W 100.0
Scheelite CO Magnetic 3.1 1.92 W 13.9
(155) Nonmagnetic 96.9 0.38 W 86.1
Calculated feed 100.0 0.428 W 100.0
Scheelite CO Magnetic· 2.8 2.36 W 15.2
(165) Nonmagnetic 97.2 0.38 W 84.8
Calculated feed 100.0 0.435 W 100.0
Scheelite CO 0 Magnetic 1.5 1.18 W 3.8
(165) Nonmagnetic 98.5 0.45 W 96.2
Calculated feed 100.0 0.461 W 100.0
Scheelite NH) 8 Magnetic 2.4 4.53 W 23.6
(135) Nonmagnetic 97.6 0.36 W 76.4
Calculated feed 100.0 0.460 W 100.0
Scheelite NH) 0 Magnetic 1.3 1.02 W 3.2
(135) Nonmagnetic 98.7 0.40 W 96.8
Calculated feed 100.0 0.408 W 100.0
Scheelite CH4 Magnetic 42.0 0.95 W 85.1
(135) Nonmagnetic 58.0 0.12 W 14.9
Calculated feed 100.0 0.469 W 100.0
Scheelite CH4 0 Magnetic 1.57 1.25 W 4.3
(135) Nomagnetic 98.43 0.44 W 95.7
Calculated feed 100.00 0.45 W 100.0
Scheelite CZH4 Magnetic 21.2 1.74 W 79.6
(135) Nonmagnetic 78.8 0.12 W 20.4
Calculated feed 100.0 0.464 W 100.0
Scheelite CZH4 0 Magnetic 1.23 1.42 W 3.7
(135) Nonmagnetic 98.77 0.46 W 96.3
Calculated feed 100.00 0.471 W 100.0
Pyrochlore liz Magnetic 10.2 0.66 Nb 69.4
(124) Nonmagnetic 89.8 0.033 Nb 30.6
Calculated feed 100.0 0.10 Nb 100.0
Pyrochlore Hz 0 Magnetic 1.04 2.4 Nb 24.7
(124) Nonmagnetic 98.96 0.077 Nb 75.3
Calculated feed 100.00 0.10 Nb 100.0
Hematite Hz Magnetic 0.96 39.0 Fe 37.1
(125) Nonmagnetic 99.04 0.64 Fe 62.9
Calculated feed 100.00 1.01 Fe 100.0
Hematite Hz 0 Magnetic 0.14 22.5 Fe 3.4
(125) Nonmagnetic 99.86 0.91 Fe 96.6
Calculated feed 100.00 0.94 Fe 100.0
EXAMPLE 6 raised to 330· C. over this 60 minute treatment time.
A sample of scheelite was ground to minus 65-mesh Another sample of this ore was also treated for 60 minand
mixed with minus 65-mesh silica sand to produce a 65 utes with 16 kilograms of ferric chloride per metric ton
3% synthetic ore. A sample of this ore was treated for of feed with the temperature being slowly raised to 330·
60 minutes with 16 kilograms of ferrous chloride per C. over this time period.To obtain comparative results,
metric ton of feed with the temperature being slowly another sample was treated exactly the same as the first
4,257,881
13
two examples with the omission of the ferrous chloride
ad ferric chloride. Table 6 contains the results of the
magnetic separation of these samples.
14
monoxide, ammonia, and lower hydrocarbons in the
range of about CI to C8.
4. The process of claim 1 or claim 2 wherein the metal
TABLE 6
TUNGSTEN
IRON DOSAGE WEIGHT GRADE DISTRIBUTION
COMPOUND (kg./m.ton) PRODUCT (%) (%) (%)
None Magnetic 1.25 1.81 4.9
Nonmagnetic 98.75 0.444 95.1
Calculated feed 100.0 0.46 100.0
FeClz 16 Magnetic 2.2 4.77 23.7
Nonmagnetic 97.8 0.345 76.3
Calculated feed 100.0 0.44 100.0
FeCI) 16 Magnetic 1.10 2.25 6.5
Nonmagnetic 98.90 0.36 93.5
Calculated feed 100.0 0.38 100.0
EXAMPLE 7
Samples of the same scheelite ore used in Example 6 20
were cotreated with ferrous chloride and hydrogen gas
and ferric chloride and hydrogen gas. Each of these
samples was treated for 60 minutes with 16 kilograms of
the iron chloride per metric ton of feed. The temperature
was slowly raised to 3300 C. over this 60 minute 25
treatment time. The hydrogen gas was introduced to
the system prior to its heat-up at a rate of one reactor
volume of hydrogen gas every 4.3 minutes for a period
of 15 minutes. Comparative results were obtained by
treating another sample of the ore to the same process 30
with the omission of the iron chloride. All the samples
were subjected to a magnetic separation process and
Table 7 contains the comparative results of the different
samples.
TABLE 7
containing compound is a carbonyl.
5. The process of claim 4 wherein the carbonyl is
selected from the group consisting of iron, cobalt and
nickel.
6. The process of claim 5 wherein the iron carbonyl
comprises iron pentacarbonyl.
7. The process of claim 1 wherein the metal containing
compound is an iron containing compound.
8. The process of claim 7 wherein the iron containing
compound is selected from the group consisting of iron
carbonyl, ferrocene, ferrocene derivatives, ferric acetylacetonate,
ferric acetylacetonate derivatives, ferrous
chloride and ferric chloride.
9. The process of claim 1 or claim 2 wherein the
process is conducted at a temperature within a range of
1250 C. less than the general decomposition temperature
of the metal compound in a specific system for the ore
TUNGSTEN
IRON DOSAGE WEIGHT GRADE DISTRIBUTION
COMPOUND (kg./m.ton) GAS PRODUCT (%) (%) (%)
FeClz 16 Hz Magnetic 2.0 4.37 18.7
Nonmagnetic 98.0 0.389 81.3
Calculated feed 100.0 0.47 100.0
FeCI) 16 Hz Magnetic 1.28 2.37 8.4
Nomnagnetic 93.72 0.337 91.6
Calculated feed 100.0 0.36 100.0
None H2 Magnetic 1.65 2.04 6.9
Nonmagnetic 98.35 0.461 93.1
Calculated feed 100.0 0.49 100.0
What is claimed is:
1. A process for beneficiating metal oxide ores se- 50
lected from the group consisting of bauxite, apatite, and
the metal oxides of Groups IIIB, IVB, VB, VIB, VIIB,
VIIIB, IB, lIB and IVA which comprises contacting
the metal oxide ore with a metal containing compound
under conditions which cause the metal containing 55
compound to react substantially at the surface of the
metal oxide particles to the substantial exclusion of the
gangue particles so as to alter the surface characteristics
of the metal values thereby causing a selective enhancement
of the magnetic susceptibility of the metal oxide 60
values to the exclusion of the gangue in order to permit
a physical separation between the values and the
gangue.
2. The process of claim 1 wherein the metal oxide ore
is cotreated with the metal containing compound and a 6S
reducing gas.
3. The process of claim 2 wherein the reducing gas is
selected from the group consisting of hydrogen, carbon
being treated.
10. The process of claim 1 or claim 2 wherein the
metal containing compound is employed in an amount
offrom about 0.1 to 100 kilograms per metric ton of ore.
11. The process of claim 2 wherein the reducing gas
is employed at a rate of at least about 1 percent of the
reactor atmosphere.
12. A process for beneficiating metal oxide ores selected
from the group consisting ofbauxite, apatite, and
the metal oxides of Groups IIIB, IVB, VB, VIB, VIIB,
VIIIB, IB, lIB, and IVA which comprises contacting
the metal oxide ore in a specific system with from about
0.1 to about 100 kilograms of a metal containing compound
at a temperature within a range of 1250 C. less
than the general decomposition temperature of the
metal containing compound in a specific system for the
ore being treated for a period of time from about 0.05 to
about 4 hours under conditions which cause the metal
containing compound to react substantially at the surface
of the metal oxide particles to the substantial exclusion
of the gangue particles so as to alter the surface
25
4,257,881
16
exclusion of the gangue in order to permit a magnetic
separation between the values and the gangue.
26. The process of claim 25 wherein the iron containing
compound is iron pentacarbonyl and the tempera-
5 ture of the process is conducted within a range of about
IS· C. less than the general decomposition temperature
of the iron pentacarbonyl in the specific system for the
ore being treated.
27. The process of claim 26 wherein the metal oxide
ore is pyrochlore.
28. The process of claim 26 wherein the metal oxide
ore is uraniriite.
29. The process of claim 26 wherein the metal oxide
ore is cuprite.
30. The process of claim 26 wherein the metal oxide
ore is cassiterite.
31. The process of claim 26 wherein the metal oxide
ore is rutile.
32. The process of claim 26 wherein the metal oxide
ore is bauxite.
33. The process of claim 26 wherein the metal oxide
ore is carnotite.
34. The process of claim 26 wherein the metal oxide
ore is scheelite.
35. The process of claim 26 wherein the metal oxide
ore is hematite.
36. The process of claim 26 wherein the metal oxide
ore is apatite.
37. The process of claim 25 wherein the iron containing
compound is ferrocene and the treatment is conducted
at a temperature within a range of about SO· C.
less than the general decomposition temperature of
ferrocene in the specific system for the ore being
treated.
38. The process of claim 37 wherein the metal oxide
ore is bauxite.
39. The process of claim 37 wherein the metal oxide
ore is scheelite.
40. The process of claim 37 wherein the metal oxide
ore is carnotite.
41. The process of claim 37 wherein the metal oxide
ore is apatite.
42. The process of claim 37 wherein the metal oxide
ore is cuprite.
43. The process of claim 37 wherein the metal oxide
ore is uraninite.
44. The process of claim 2S wherein the iron containing
compound is ferric acetylacetonate.
45. The process of claim 44 wherein the metal oxide
ore is bauxite.
46. The process of claim 44 wherein the metal oxide
ore is scheelite.
47. The process of claim 44 wherein the metal oxide
ore is carnotite.
48. The process of claim 44 wherein the metal oxide
ore is apatite.
49. The process of claim 25 wherein the iron containing
compound is ferrous chloride.
50. The process of claim 49 wherein the metal oxide
ore is scheelite.
51. The process of claim 25 wherein the iron containing
compound is ferric chloride.
52. The process of claim SI wherein the metal oxide
ore is scheelite.
53. The process of claim 25 wherein the metal oxide
ore is cotreated with the iron containing compound and
a reducing gas selected from the group consisting of
hydrogen, carbon monoxide, ammonia, methane, and
15
characteristics of the metal values thereby causing a
selective enhancement of the magnetic susceptibility of
the metal oxide values to the exclusion of the gangue in
order to permit a physical separation between the values
and the gangue.
13. The process of claim 12 wherein the metal oxide
ore is cotreated with the metal containing compound
and a reducing gas employed at a rate of at least about
10 percent of the reactor atmosphere.
14. The process of claim 12 or claim 13 wherein the 10
metal containing compound is a carbonyl.
15. The process of claim 14 wherein the carbonyl is
selected from the group consisting of iron, cobalt and
nickel.
16. The process of claim 15 wherein the iron carbonyl 15
comprises iron pentacarbonyl.
17. The process of claim 12 wherein the metal containing
compound is an iron containing compound.
18. The process of claim 17 wherein the iron containing
compound is selected from the group consisting of 20
iron carbonyl, ferrocene, ferric acetylacetonate, ferrous
chloride and ferric chloride.
19. The process of claim 1 or claim 12 wherein the
mineral values are physically separated from the gangue
by a magnetic separation process.
20. The process of claim 19 wherein the magnetic
separation process is a wet magnetic process.
21. The process of claim 1 or claim 12 wherein the
mineral values are physically separated from the gangue
by an electrostatic technique. 30
. 22. The process of claim 12 wherein the metal containing
compound is employed in an amount of from
about I to about 50 kilograms per metric ton of ore and
the process is carried out at a temperature within a
range of SO· C. less than the general decomposition 35
temperature of the metal containing compound in a
specific system for the ore being treated for a period of
time from about 0.15 to about 2 hours.
23. The process of claim 14 wherein the metal carbonyl
is employed in an amount of from 1 to about SO 40
kilograms per metric ton of ore and the treatment process
is carried out at a temperature within a range of IS·
C. less than a general decomposition temperature of the
metal carbonyl in a specific system for the ore being
treated for a period of time from about 0.25 to about 1 45
hour.
24. The process of claim 13 wherein the metal containing
compound is employed in an amount from about
1 to about 50 kilograms per metric ton of ore and the
reducing gas is employed at a rate of about 100 percent 50
reactor atmosphere.
25. A process for beneficiating metal oxide ores selected
from the group consisting of taconite, bauxite,
apatite, rutile, pyrochlore, uraninite, cuprite, cassiterite,
carnotite, scheelite and hematite which comprises con- 55
tacting the metal oxide ore in a specific system 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 125· C. less than the general decomposition
temperature of the iron containing compound in the 60
specific system for the ore being treated for a time period
from about 0.15 to 2 hours under conditions which
cause the iron containing compound to react substantially
at the surface of the metal oxide particles to the
substantial exclusion of the gangue particles so as to 65
alter the surface characteristics of the metal values
thereby causing a selective enhancement of the magnetic
susceptibility of the metal oxide values to the
4,257,881
18
57. The process of claim 54 wherein the metal oxide
ore is scheelite.
58. The process of claim 54 wherein the metal oxide
ore is hematite and the reducing gas is hydrogen.
59. The process of claim 53 wherein the metal oxide
ore is scheelite, the iron containing compound is ferrous
chloride and the reducing gas is hydrogen.
6(1. The process of claim 53 wherein the metal oxide
ore is scheelite, the iron containing compound is ferric
10 chloride and the reducing gas is hydrogen.
* * * * *
17
ethylene at a rate of about 100 percent reactor atmosphere.
54. The process of claim 53 wherein the iron containing
compound is iron pentacarbonyl.
55. The process of claim 54 wherein the metal oxide 5
ore is bauxite and the reducing gas is selected from the
group consisting of hydrogen and carbon monoxide.
56. The process of claim 54 wherein the metal oxide
ore is apatite and the reducing gas is selected from the
group consisting of hydrogen and carbon monoxide.
15
20
25
30
35
40
45
50
55
60
65