United States Patent [19]
Kindig et al.
[11]
[45]
4,289,528
* Sep. 15, 1981
[21] Appl. No.: 93,902
[22] Filed: Nov. 13, 1979
[54] PROCESS FOR BENEFICIATING SULFIDE
ORES
[75] Inventors: James K. Kindig, Arvada; Ronald L.
Turner, Golden, both of Colo.
[73] Assignee:
[*] Notice:
Hazen Research, Inc., Golden, Colo.
The portion of the term of this patent
subsequent to Jun. 3, 1997, has been
disclaimed.
3,490,899 1/1970 Krivisky et aI. 423/25
3,669,644 6/1972 Sato 423/25
3,671,197 6/1972 Mascro 75/6
3,758,293 9/1973 Viviani et aI. 75/6
3,926,789 1211975 Shubert 2091214
3,938,966 211976 Kindig et aI. 44/1 R
4,056,386 11/1977 McEwan et aI. 423/417
4,098,584 7/1978 Kindig et aI. 44/1 R
4,119,410 10/1978 Kindig et aI. 44/1 R
4,120,665 10/1978 Kindig et aI. 44/1 R
4,187,170 211980 Westcott 209/8
4,205,979 6/1980 Kindig et aI. 2091214
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 2091212
OTHER PUBLICATIONS
Henderson, J. G. et at, 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
Related U.S. Application Data
[63] Continuation-in-part of Ser. No. 921,582, JuI. 3, 1978,
abandoned.
[51] Int. CI.3 C22B 1/00
[52] U.S. CI 75/1 R; 209/8;
209/9; 209/11; 209/127R; 209/212; 209/214
[58] Field of Search 75/1 R, 1 T, 21, 28,
75/62, 72, 77, 82, 83, 111, 112; 423/23, 25, 138;
209/8,9, 11,212-214, 127 R, 127 A; 427/47,
252-255
[56] References Cited
U.S. PATENT DOCUMENTS [57] ABSTRACT
933,717 9/1909 Lockwood et aI. 2091214
1,053,486 211913 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 4271217
3,252,791 5/1966 Frysinger et aI. 75/119
3,323,903 6/1967 O'Neill et aI. 75/0.5
3,466,167 9/1969 IIIis·et aI. 75/112
One or more mineral values of sulfide ores are beneficiated
by cotreating the sulfide ore with a metal containing
compound and a reducing gas 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 Claims, No Drawings
CROSS-RELATED PATENT APPLICATIONS
PROCESS FOR BENEFICIATING SULFIDE ORES
This application is a continuation-in-part application 5
of U.S. Ser. No. 921,582 filed July 3, 1978 now abandoned.
The process of the present invention is particularly
useful for concentrating sulfide minerals. The process 65
employs the simultaneous cotreatment of the sulfide ore
with a metal containing compound and a reducing gas
in order to selectively enhance the magnetic susceptibil-
4,289,528
1
TECHNICAL FIELD
This invention relates to a means for treating 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 magnetically removed
from the gangue.
BACKGROUND ART
2
ity of various mineral values contained within the ore.
The treated mixture can then be treated by magnetic
means 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 of any type
has a specifically defined magnetic susceptibility, which
refers to the overall attraction of the compound to a
magnetic force. An alteration of the surface magnetic
10 characteristics will alter the magnetic susceptibility.
The metal and gas cotreatment of the inventive process
alters 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 sus15
ceptibility of the original particle is not actually
changed, but the particle itself is changed, at least at its
As is well-known, mining operations in the past for surface, resulting in a different particle possessing a
recovering various metals, e.g., lead, copper, have uti- greater magnetic susceptibility than the original partilized
high grade ore deposits where possible. Many of cle. For convenience of discussion, this alteration is
these deposits have been exhausted and mining oflower 20 termed herein as "enhancing the magnetic susceptibilgrade
ores is increasing. The processing of these leaner ity" of the particle or ore itself.
ores consumes large amounts of time, labor, reagents, The sulfide minerals which are capable of undergoing
power and water with conventional processing. a selective magnetic enhancement in accordance with
In addition to the increased expense associated with the process include the metal sulfides of groups VIE,
the extraction of these metals from low grade ores, 25 VIIB, VIIIB, IB, lIB, IlIA, IVA and VA. These sulproposed
processes for separation of certain of the sul- fides preferably specifically include the sulfides of mofide
ores are technically very difficult and involve elab- lybdenum, tungsten, manganese, rhenium, iron, mtheorate
and expensive equipment. In many cases the ex- nium, osmium, cobalt, rhodium, iridium, nickel, pallapense
incurred by such separation would be greater dium, platinum, copper, gold, silver, zinc, cadmium,
than the commercial value of the metal, such that the 30 mercury, tin, lead, arsenic, antimony and bismuth;
mineral recovery, while theoretically possible, is economically
unfeasible. The gangue minerals from which the metal sulfid.es
U.S. Pat. No. 4,098,584 "Removal of Impurities from can be separated include those minerals which do not
Coal", Ser. No. 767,659, filed Feb. 10, 1977, discloses undergo a sufficient magnetic susceptibility enhancethe
cotreatment of coal with a metal containing com- 35 ment as a result of the process. These gangue minerals
pound and a gas selected from the group consisting of include, for example, silica, alumina, gypsum, muscohydrogen
and carbon monoxide in order to selectively vite, dolomite, calcite, albite and feldspars, as well as
enhance the magnetic susceptibility of various impuri- various other minerals. The term gangue as used herein
ties contained within the coal. This process selectively refers to inorganic minerals with which sulfide ores are
enhances both sulfides and various oxides to the exclu- 40 normally associated. The term does not include coal.
sion of coal. In those ores which contain naturally relatively
Copending patent application "Process for Benefici- strongly magnetic constituents, such as magnetite, the
ating Ores", Ser. No. 921,582 filed July 3, 1978 discloses magnetic material may first be removed by passing the
a method for beneficiating the mineral values ofsulfide mixture through a magnetic separator. The nonmagores
by contacting the ore mixture with an iron car- 45 netic portion obtained by this precleaning step is then
bonyl in order to selectively enhance the magnetic sus- subjected to the cotreatment with a metal containing
ceptibility of the mineral values. It has been found that compound and the reducing gas.
this method of beneficiating mineral values can be sig- Prior to the cotreatment, the oni must be ground to
nificantly improved by cotreating the sulfide ores with substantially liberate the metal sulfideparticles from the
an iron containing compound and a reducing gas as 50 gangue particles, if the respective components do not
hereinafter described. already exist in this liberated state. The ore may be
cmshedfiner than necessary to achieve liberation, but
DISCLOSURE OF THE INVENTION this is not generally economically possible. It is gener-
The process of the present invention entails cotreat- ally satisfactory to crush the ore to minus 14 mesh,
ing a metal sulfide ore mixture with a metal containing 55 although some ores require finer mesh sizes.·
compound and a reducing gas under processing condi- Numerous metal containing compounds are capable
tions such that the magnetic susceptibility of the ore is of enhancing the magnetic susceptibility ofthe metal
selectively enhanced. to the exclusion of the gangue. sulfides in accordance· with the invention. Many iron
The affected ore values may then be magnetically sepa- containing compounds possess the capability of enhancrated
from the less magnetic constituents. .60 ing the magnetic susceptibility of the mineral values of
the ore, as long as the compound is adaptable so as to
BEST MODEFOR CARRYING OUT THE bring the iron in the compound into contact with.the
INVENTION . mineral value under conditionssuch as to cause an alteration
· of at least a portion of the surface of the mineral
value.
Iron containing ~ompoundscapable of exerting suffi"
cient vapor pressure, with iron as a component in the
vapor, so as to bring the ironinto contact with the value
4,289,528
3
at the reaction temperature are suitable, as weil 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
ore. Preferred compounds within the vapor pressure 5
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 temper- 10
ature. 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 15
enhance the magnetic susceptibility include those
which may be homongeneously 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 20
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. 25
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 com- 30
pounds 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 35
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 40
of organic acids, and beta-diketone compounds of iron.
Specific examples include ferrous formate, I,l'-diacetyl
ferrocene, and 1,1'-dihydroxymethyl ferrocene.
Various inorganic compounds are also capable of
producing an enhanced magnetic susceptibility. Pre- 45
ferred 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 compounds.
Iron carbonyl is a preferred carbonyl for im- 50
parting this magnetic susceptibility, particularly iron
pentacarbonyl, iron dodecacarbonyl and iron nonacarbony!.
The more preferred metal containing compounds
capable of enhancing the magnetic susceptibility
are iron pentacarbonyl, ferrocene and ferric acetyl- 55
acetonate, with iron pentacarbonyl being the most preferred.
The process is applied by contacting the iron containing
compounds with the ore at a temperature wherein
the iron containing compound selectively decomposes 60
or otherwise reacts at the surface of the metal sulfide
particles to alter their surface characteristics, while
remaining essentially unreactive, or much less reactive,
at the surface of the gangue particles. The temperatuce
of the reaction is a critical parameter, and dependent 65
primarily upon the particular compound, the cotreating
gas and the particular ore. The preferred temperature
can be determined by heating a sample of the specific
4-
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 the cotreatment gas
being utilized. It is generally preferred to select a temperature
which is within a range of 1250 c., more preferably
500 C., and most preferably ISO 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 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 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 1 to about 50 kilograms per metric
ton of feed, and most preferably from about 2 to 20
kilograms per metric ton of feed. The cotreatment reaction
is generally conducted for a period of time of from
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
co-treating the ore with a metal containing compound
as hereinabove discussed, while simultaneously treating
the ore with a reducing gas. Preferred gases include
those selected from the group' 'nsisting of hydrogen,
carbon monoxide, ammonia, and lower hydrocarbons in
the range of about Cj to eg, particularly including
methane, ethane, ethylene, propane, propylene, butane
and butylene, as well as other similar reducing gases.
These gases in and of themselves have no appreciable
effect upon the magnetic susceptibility of the mineral
values; however, they significantly 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
gas is available to the metal containing compound during
the treatment
4,289,528
5
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
of preferably at least about I percent, more preferably
at least about 10 percent and most preferably about 100 5
percent of the reactor atmosphere.
After the feed mixture containing the metal sulfide
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 sulfides 10
from the gangue. Any of many commercially available
magnetic separators can be used to remove these values
from the gangue. For example, low or medium intensity
separations can be made with a permanent magnetic
drum separator, electromagnetic drum separators, in- 15
duced roll separators or other configurations known to
those skilled in the art. Since most sulfides are liberated
at a mesh size of 65 mesh or finer, a wet magnetic sepa-
6
EXAMPLE I
Samples of 3 percent galena in silica sand matrix,
sized to a minus 65 mesh, were subjected to processing
as follows. The first sample was merely treated at a
temperature of 136° C. for 30 minutes. A second sample
was treated exactly the same with the additional treatment
of 8 kilograms of iron pentacarbonyl per metric
ton of the galena mixture. Additional samples were
treated as the second sample, and also were cotreated
with various gases as specified in Table 1. Each of these
cotreatment samples was heated to 136° c., then the
system was purged with 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 the iron carbonyl
treatment. The comparative results are given below in
Table 1. The metal analyzed in all cases was lead.
, TABLE I
Fe(CO)s Galena
Dosage Weight Grade Distribution
(kg./m. ton) Cotreatment Fraction (%) (%) (%)
0 None Magnetic 0.55 4.07 1.2
Nonmagnetic 99.45 1.90 98.8
Calculated Feed 100.00 1.91 100.0
None Magnetic 38.8 6.78 86.5
Nonmagnetic 61.2 0.673 13.5
Calculated Feed 100.00 3.04 100.0
HZ Magnetic 10.4 15.2 78.6
Nonmagnetic 89.6 0.481 21.4
Calculated Feed 100.0 2.01 100.0
0 HZ Magnetic .60 16.0 5.3
Nonmagnetic 99.40 1.79 94.7
Calculated Feed 100.0 1.88 100.0
8 CO Magnetic 3.2 51.5 70.5
Nonmagnetic 96.8 0.713 29.5
Calculated Feed 100.0 2.34 100.0
0 CO Magnetic .56 7.41 1.7
Nonmagnetic 99.44 2.31 98.3
Calculated Feed 100.00 2.34 100.0
8 NH3 Magnetic 3.8 27.3 80.0
Nonmagnetic 96.2 0.269 20.0
Calculated Feed 100.0 1.30 100.0
0 NH3 Magnetic 0.47 8.31 2.0
Nonmagnetic 99.53 1.94 98.0
Calculated Feed 100.00 1.97 100.0
8 CH4 Magnetic 64.0 2.98 92.1
Nonmagnetic 36.0 0.454 7.9
Calculated Feed 100.0 2.07 100.0
0 CH4 Magnetic 0.48 II.3 2.7
Nonmagnetic 99.52 1.97 97.3
Calculated Feed 100.00 2.01 100.0
8 CZH4 Magnetic 42.4 4.3 91.3
Nonmagnetic 57.6 0.303 8.7
Calculated Feed 100.0 2.00 100.0
0 CZH4 Magnetic 0.59 12.2 3.3
Nonmagnetic 99.41 2.13 96.7
Calculated Feed 100.00 2.19 100.0
55
ration 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 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 parti.
cle's magnetic characteristics. Additionally, due to the
fact that the sulfide surface characteristics have been
altered, the sulfides are often more amenable to processes
such as flotation and chemical leaching.
EXAMPLE 2
Samples of 3 percerit sphalerite mixed in a silica matrix
were heated to 132° C. for 30 minutes. All of the
samples which were treated with iron carbonyl were
treated for 30 minutes with the carbonyl at a rate of 8
60 kilograms iron carbonyl per metric ton of ore. Again,
for the samples which were cotreated with a gas, the
sample was heated to 132° C. and then the systemwas
purged with the gas for 15minutes.ata flow ratesuch
that one reactor volume of reducing gas is introduced
65 into the system every 4.3. minutes. This was immediately
followed by the iron carbonyl treatrrient.The
results of the analyses for zinc are presented below in
Table 2. .
4,289,528
7 8
TABLE 2
Fe(CO)s Sphalerite
Dosage Co- Weight Grade Distribution
(kg./m. ton) treatment Fraction (%) (%) (%)
0 None Magnetic 0.15 3.26 0.3
Nonmagnetic 99.85 1.54 99.7
Calculated Feed 100.00 1.54 100.0
8 None Magnetic 8.4 11.5 56.7
Nonmagnetic 91.6 0.804 43.3
Calculaied Feed 100.0 1.70 100.0
8 Hz Magnetic 1.8 45.3 39.9
Nonmagnetic 98.2 1.25 60.1
Calculated Feed 100.0 2.04 100.0
0 Hz Magnetic .48 11.1 3.6
Nonmagnetic 99.52 1.33 96.4
Calculated Feed 100.00 1.37 100.0
CO Magnetic 0.24 13.8 2.1
Nonmagnetic 99.76 1.58 97.9
Calculated Feed 100.00 1.61 100.0
0 CO Magnetic .42 9.29 2.6
Nonmagnetic 99.58 1.52 97.4
Calculated Feed 100.00 1.55 100.0
8 NH3 Magnetic 4.6 35.2 81.2
Nonmagnetic 95.4 0.394 18.8
Calculated Feed 100.0 2.00 100.0
0 NH3 Magnetic 0.44 9.78 2.5
Nonmagnetic 99.56 1.66 97.5
Calculated Feed 100.00 1.70 100.0
8 CZH4 Magnetic 17.4 6.74 71.6
Nonmagnetic 82.6 0.562 28.4
Calculated Feed 100.0 1.64 100.0
0 CZH4 Magnetic 0.42 7.57 2.0
Nonmagnetic 99.58 1.55 98.0
Calculated Feed 100.00 1.58 100.0
EXAMPLE 3
treatments as described in Example 2. The results of
analyses for molybdenum are shown below in Table 3.
Samples of 5 percent molybdenite mixed with a silica
matrix were heated to 1300 C. and subjected to various
TABLE 3
Fe(CO)s Molybdenite
Dosage Weight Grade Distribution
(kg./m. ton) Cotreatment Fraction (%) (%) (%)
0 None Magnetic 0.57 4.32 18.9
Nonmagnetic 99.43 0.106 81.1
Calculated Feed 100.00 0.130 100.0
None Magnetic 14.0 1.08 92.1
Nonmagnetic 86.0 0.Q15 7.9
Calculated Feed 100.0 0.164 100.0
Hz Magnetic 5.4 2.12 77.0
Nonmagnetic 94.6 0.036 23.0
Calculated Feed 100.0 0.148 100.0
0 Hz Magnetic .61 2.63 11.9
Nonmagnetic 99.39 0.120 88.1
Calculated Feed 100.00 0.14 100.0
CO Magnetic 1.1 10.58 71.5
Nonmagnetic 98.9 0.047 28.5
Calculated Feed 100.0 0.162 100.0
0 CO Magnetic .61 3.40 13.3
Nonmagnetic 99.39 0.136 86.7
Calculated. Feed 100.00 0.16 100.0
NH3 Magnetic 2.1 8.51 89.2
Nonmagnetic 97.9 0.022 10.8
Calculated Feed 100.0 0.201 100.0
0 NH3 Magnetic 0.72 3.09 18.2
Nonmagnetic 99.28 0.101 81.8
Calculated Feed 100.00 0.122 100.0
8 CH4· Magnetic 4.6 3.88 94.0
Nonmagnetic 95.4 0.012 6.0
Calculated Feed 100.0 0.189 100.0
0 CH4 Magnetic 0.60 3.74 16.0
Nonmagnetic 99.40 0.119 84.0
Calculated Feed 100.00 0.141 100.0
CZH4 Magnetic 7.3 2.45 94.6
Nonmagnetic 92.7 0.011 5.4
Calculated Feed 100.0 0.189 100.0
0 CZH4 Magnetic 0.55 3.53 14.2
Nonmagnetic 99.45 0.118 85.8
I
/
4,289,528
9
TABLE 3-continued
10
Fe(COls
Dosage
(kg./m. ton) Cotreatment Fraction
Calculated Feed
Weight Grade
(%) (%)
100.00 0.136
Molybdenite
Distribution
(%)
100.0
EXAMPLE 4
Samples of 3 percent galena mixed in a silica matrix
were cotreated with ferrocene and hydrogen and also
ferrocene with carbon monoxide. The galena was also
tests were made at 2700 C. Again, for the cotreatments,
the system was purged with the designated cotreatment
10 gas before adding the ferric acetylacetonate as a vapor.
The comparative results are presented below in Table 4.
TABLE 4
Ferrocene 0
Ferric 0
Acetylacetonate
Ferric 16
Acetylacetonate
Ferric 16
Acetylacetonate
Ferric 0
Acetylacetonate
Ferric 16
Acetylacetonate
Ferric 0
Acetylacetonate
o None
Dosage
Compound (kg/m ton) Gas
Ferrocene
Ferrocene
Ferrocene
Ferrocene
Ferrocene
Ferrocene
Ferrocene
16
16
o
16
o
16
None
CO
CO
None
None
CO
CO'
Galena
Weight Grade Distr.
Fraction (%) (%) (%)
Magnetic 0.48 10.2 2.4
Nonmagnetic 99.52 1.99 97.6
Calculated Feed 100.00 2.03 100.0
Magnetic 5.1 9.73 22.7
Nonmagnetic 94.9 1.79 77.3
Calculated Feed 100.0 2.20 100.0
Magnetic 2.1 24.4 22.9
Nonmagnetic 97.9 1.76 77.1
Calculated Feed 100.0 2.24 100.0
Magnetic 1.21 15.9 9.3
Nonmagnetic 98.79 1.90 90.7
Calculated Feed 100.00 2.07 100.0
Magnetic 2.8 27.6 44.0
Nonmagnetic 96.2 1.01 56.0
Calculated Feed 100.0 1.75 100.0
Magnetic 0.80 10.3 3.6
Nonmagnetic 99.2 2.23 96.4
Calculated Feed 100.0 2.29 100.0
Magnetic 1.41 37.1 22.3
Nonmagnetic 98.59 1.85 77.7
Calculated Feed 100.00 2.35 100.0
Magnetic 0.88 8.35 3.6
Nonmagnetic 99.12 1.97 96.4
Calculated Feed 100.00 2.03 100.0
Magnetic 0.52 6.93 1.9
Nonmagnetic 99.48 1.86 98.1
Calculated Feed 100.00 1.89 100.0
Magnetic 4.5 4.11 9.4
Nonmagnetic 95.5 1.86 90.6
Calculated Feed 100.0 1.96 100.0
Magnetic 5.5 4.61 13.4
Nonmagnetic 94.5 1.74 86.6
Calculated Feed 100.0 1.90 100.0
Magnetic 0.47 8.38 1.8
Nonmagnetic 99.53 2.16 98.2
Calculated Feed 100.00 2.19 100.0
Magnetic 3.8 4.25 7.7
Nonmagnetic 9.6.2 2.01 92.3
Calculated Feed 2.09 100.0
Magnetic 0.60 11.4 3.5
Nonmagnetic 99.40 1.92 96.5
Calculated Feed 100.00 1.98 100.0
treated alone with each of the gases for comparative
purposes. These processes were carried out at a temperature
of 4000 C. and the cotreatment was carried out as 55
in a previous example with the ferrocene being applied
through a solvent deposition. Additionally, samples of 3
percent galena were cotreated with ferricacetylacetonate
and hydrogen gas, and additioniil samples were
treated with ferric· acetylacetonat~ and carbon monox- 60
ide. Comparative data were also obtained by treating
the galena in accordance with the same procedure with.
the omission of the ferri<:: acetylacetonate;Allof these
EXAMPLE 5
Samples of 3 percent sphalerite mixed in a silica matrix
were cotreated with ferric acetylacetonate and
hydrogen gas and additional samples were treated with
ferrocene and hydrogen gas as described in Example 4.
Comparative data were obtained by treating thesphalerite
·in accordance· with the· same procedure but with
the. omission of .ferric acetylacetom~te and ferrocene,
respectively. Table· 5 gives. the comparative results.
TABLE 5
Iron..
Compound
Ferric
. Dosage
(kg/m ton)
o
Gas
None
Product
Magnetic
·Sphaletite
Weight· Grade· Di.tr.
.(%) • (%) . (%).
0.54 10.23.1
11
4,289,528
12
TABLE 5-continued
Iron
Sphalerite
Dosage Weight Grade Distr.
Compound (kg/m ton) Gas Product (%) (%) (%)
Acetylacetonate Nonmagnetic 99.46 1.72 96.9
Calculated Feed 100.00 1.77 100.0
Ferric 16 None Magnetic 5.1 5.63 16.8
Acetylacetonate Nonmagnetic 94.9 1.52 83.2
Calculated Feed 100.0 1.73 100.0
Ferric 16 Hz Magnetic 7.3 4.72 22.0
Acetylacetonate Nonmagnetic 92.7 1.32 78.0
Calculated Feed 100.0 1.57 100.0
Ferric 0 Hz Magnetic 0.45 8.62 2.4
Acetylacetonate Nonmagnetic 99.55 1.59 97.6
Calculated Feed 100.00 1.62 100.0
Ferrocene 0 None Magnetic 0.49 6.19 1.8
Nonmagnetic 99.51 1.63 98.2
Calculated Feed 100.00 1.65 100.0
Ferrocene 16 None Magnetic 4.1 8.59 21.5
Nonmagnetic 95.9 1.34 78.5
Calculated Feed 100.0 1.63 100.0
Ferrocene 16 Hz Magnetic 0.76 13.8 6.0
Nonmagnetic 99.24 1.65 94.0
Calculated Feed 100.00 1.74 100.0
Ferrocene 0 HZ Magnetic 0.85 12.9 6.0
Nonmagnetic 99.15 1.72 94.0
Calculated Feed 100.00 1.82 100.0
EXAMPLE 6
Samples of 5 percent molybdenite mixed in a silica
matrix were cotreated with ferric acetylacetonate and
hydrogen gas and also with ferrocene and hydrogen gas
as described in Example 4. Comparative data were obtained
by treating the molybdenite in accordance with
the same procedure but with the omission of ferric acetylacetonate
and ferrocene, respectively. Table 6 gives
the comparative results.
TABLE 6
purged with the hydrogen gas for 15 minutes at a flow
rate such as one reactor volume of gas was introduced
into this system every 4.3 minutes. Comparative results
30 were obtained by treating another set of samples exactly
the same with the omission of ferrous chloride and
ferric chloride. All of the samples were subjected to a
magnetic separation process and the results are presented
below in Table 7.
Iron
Molybdenite
Dosage Weight Grade Distr.
Compound (kg/m ton) Gas Product (%) (%) (%)
Ferric 0 None Magnetic 0.55 1.04 4.1
Acetylacetonate Nonmagnetic 99.45 0.136 95.9
Calculated Feed 100.00 0.141 100.0
Ferric 16 None Magnetic 4.3 0.801 20.8
Acetylacetonate Nonmagnetic 95.7 0.137 79.2
Calculated Feed 100.0 0.166 100.0
Ferric 16 Hz Magnetic 3.0 1.58 30.6
Acetylacetonate Nonmagnetic 97.0 0.111 69.4
Calculated Feed 100.0 0.155 100.0
Ferric a Hz Magnetic 0.51 1.07 3.5
Acetylacetonate Nonmagnetic 99.49 0.150 96.5
Calculated Feed 100.00 0.155 100.0
Ferrocene 0 None Magnetic 0.68 0.961 4.4
Nonmagnetic 99.32 0.143 95.6
Calculated Feed 100.00 0.148 100.0
Ferrocene 16 None Magnetic 11.8 0.953 68.1
Nonmagnetic 82.2 0.064 31.9
Calculated Feed 100.0 0.165 100.0
Ferrocene 16 Hz Magnetic 1.5 6.67 58.9
Nonmagnetic 98.5 0.071 41.1
Calculated Feed 100.0 0.170 100.0
Ferrocene 0 HZ Magnetic 0.90 0.900 5.5
Nonmagnetic 99.10 0.140 94.5
Calculated Feed 100.00 0.147 100.0
60 TABLE 7
EXAMPLE 7
Samples of 3 percent galena in silica sand, sized to
Galena
Distriminus
65 mesh, were treated with 16 kilograms of fer- Iron Weight Grade bution
rous chloride per metric ton of ore and hydrogen bas Compound Gas Product (%) (%) (%)
and with 16 kilograms of ferric chloride per metric ton 65 FeClz Hz Magnetic 1.22 20.2 15.2
of ore and hydrogen gas and were heated over a 60 Nonmagnetic 98.78 1.39 84.4
minute time period to 3750 C. Prior to the heating of
Calculated Feed 100.0 1.62 100.0
FeCI) Hz Magnetic 2.11 38.8 67.3
each of these cotreatment samples, the system was Nonmagnetic 97.89 0.407 32.7
14
tions which cause the metal 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 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 physical separation between the
metal sulfide values and the gangue, the improvement
10 comprising:
cotreating the ore with a reducing gas during the
metal containing compound treatment and wherein
the reducing gas used in the cotreatment is in addition
to any reducing gas which may be produced
from the metal containing compound treatment.
2. The process of claim 1 wherein the gas is selected
from the group consisting of hydrogen,carbon monoxide,
ammonia, and lower hydrocarbons in the range of
about CI to C8.
3. The process of claim 2 wherein the lower hydro-
4,289,528
EXAMPLE 8
Samples of different minerals were ground to minus
65 mesh and mixed with minus 65 mesh silica sand to
produce 3 percent synthetic ores. Each sample was 15
treated for 30 minutes with 8 kilograms ofiron carbonyl
per metric ton of feed. The tempc::rature ofthe treatment
varied for the different minerals and is given below as
are the data relating to the wet magnetic recovery of
the metals. 20
13
TABLE 7-continued
Galena
Distri-
Iron Weight Grade bution
Compound Gas Product (%) (%) (%) 5
Calculated Feed 100.0 1.22 100.0
None Hz Magnetic 0.73 10.1 4.1
Nonmagnetic 99.27 1.76 95.9
Calculated Feed 100.0 1.82 100.0
TABLE 8
Yield Metal Sulfide
Temp. Wt. Grade Distribution
Mineral "C. Fraction (%) (%) Metal (%)
Bornite 140 Magnetic 3.6 29.7 Cu 78.0
Nonmagnetic 96.4 0.313 Cu 22.0
Calculated Feed 100.0 1.37 Cu 100.0
Cinnabar 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
Arsenopyrite 125 Mangetic 7.4 1.01 As 31.0
Nonmagnetic 92.6 0.18 As 69.0
Calculated Feed 100.0 0.24 As 100.0
Smaltite 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
Smaltite 115 Magnetic 1.2 3.35 Ni 22.5
Nonmagnetic 98.8 0.14 Ni 77.5
Calculated Feed 100.0 0.18 Ni 100.0
Chalcocite 140 Magnetic 3.4 50.8 Cu 90.5
Nonmagnetic 96.6 0.188 Cu 9.5
Calculated Feed 100.0 1.91 Cu 100.0
Chalcopyrite 140 Magnetic 1.8 20.5 Cu 48.4
Nonmagnetic 98.2 0.401 Cu 51.6
Calculated Feed 100.0 0.76 Cu 100.0
Orpiment 110 Magnetic 20.1 2.0 As 40.5
Nonmagnetic 79.9 0.74 As 59.5
Calculated Feed 100.0 0.99 As 100.0
Realgar 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 105 Magnetic 18.2 0.733 Ni 92.1
in Pyrrhotite Nonmagnetic 81.8 0.079 Ni 7.9
Calculated Feed 100.0 0.145 Ni 100.0
Stibnite 85 Magnetic 7.6 4.82 Sb 48.0
Nonmagnetic 92.4 0.43 Sb 52.0
Calculated Feed 100.0 0.76 Sb 100.0
Stibnite 85 Magnetic 8.1 3.56 Sb 63.4
Nonmagnetic 91.9 0.181 Sb 36.6
Calculated Feed 100.0 0.454 Sb 100.0
Tetrahedrite 117 Magnetic 2.9 4.43 Cu 68.8
Nonmagnetic 97.1 0.06 Cu 31.2
Calculated Feed 100.0 0.19 Cu 100.0
Tetrahedrite 117 Magnetic 2.9 0.256 Zn 31.0
Nonmagnetic 97.1 0.017 Zn 69.0
Calculated Feed 100.0 0.024 Zn 100.0
Tetrahedrite 117 Magnetic 2.9 0.78 Ag 85.3
Nonmagnetic 97.1 O.~ Ag 14.7
Calculated Feed 100.0 0.027 Ag 100.0
Tetrahedrite 117 Magnetic 2;9 2.34 Sb 53.4
Nonmagnetic 97.1 0.061 Sb 46.6
Calculated Feed 100;0 0.127 Sb 100.0
What is claimed is: 65
1. In a process for the beneficiation of a sulfide ore . carbon gas in. the range of about CI to C8areselected
from the gangue, excluding coal, wherein. the ore is from the group consisting of methane, ethane,ethylene,
treated with a metal containing compound under condi- propane, propylene, butane and butylene.
4,289,528
15
4. The process of claim 1 wherein the metal containing
compound and gas cotreatment is conducted 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 5
treated.
5. The process of claim 1 wherein the metal containing
compound is employed in an amount of from about
0.1 to 100 kilograms per metric ton of ore.
6. The process of claim 1 wherein the gas is employed 10
at a rate of at least about 1 percent of the reactor atmosphere.
7. In a process for the beneficiation of a metal sulfide
ore from gangue, excluding coal, wherein the ore is
treated with a metal containing compound under condi- 15
tions which cause the metal 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 values thereby causing a selective enhancement 20
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
between the metal sulfide values and the gangue in 25
improvement for the ore in a specific system comprising:
cotreating the ore with a reducing gas at a rate of at
least about 1 percent of the reactor atmosphere and
from about 0.1 to about 100 kilograms of a metal 30
containing compound per metric ton of ore at a
temperature within a range of 1250 C. less than the
general decomposition temperature of the metal
containing compound in the specific system for the
ore being treated for a period of time from about 35
0.05 to about 4 hours and wherein the reducing gas
used in the cotreatment is in addition to any reducing
gas which may be produced from the metal
containing compound treatment.
8. The process of claim 1 or claim 7 wherein the metal 40
containing compound is an iron containing compound.
9. The process of claim 8 wherein the iron containing
compound is selected from the group consisting of ferrous
chloride, ferric chloride, ferrocene, ferrocene derivatives,
ferric acetylacetonate and ferric acetylaceton- 45
ate derivatives.
10. The process of claim 1 or claim 7 wherein the
metal containing compound is a carbony1.
11. The process of claim 10 wherein the carbonyl is
selected from the group consisting or iron, cobalt and 50
nickel.
12. The process of claim 11 wherein the iron carbonyl
comprises iron pentacarbonyl.
13. The process of claim 9 wherein the gas is employed
at a rate of at least about 10 percent of the reac- 55
tor atmosphere; the metal containing compound is employed
in an amount of from about 1 to about 50 kilograms
per metric ton of ore and the cotreatment process
is carried out at a temperature within a range of 500 C.
less than the general decomposition temperature of the 60
metal containing compound in a specific system for the
ore being treated for a,period of time from about 0.15to
about 2 hours.
14.The process of claim 13 wherein the gas is employed
at a rate of about 100 percent of the reactor 65
atmosphere and the metal containing compound is employed
in an amount of from about 2 to about 20 kilograms
per metric ton of ore.
16
15. The process of claim 14 wherein the metal containing
compound is iron carbonyl and the cotreatment
process is carried out at a temperature within a range of
150 C. less than the general decomposition temperature
of the iron carbonyl in the specific system for the ore
being treated.
16. The process of claim 1 or claim 7 wherein the ore
is treated with ferrocene and a reducing gas selected
from the group consisting of hydrogen, carbon monoxide,
ammonia, methane and ethylene.
17. The process of claim 1 or claim 7 wherein the ore
is treated with ferric acetylacetonate and a reducing gas
selected from the group consisting of hydrogen, carbon
monoxide, ammonia, methane and ethylene.
18. The process of claim 1 or claim 7 wherein the ore
is treated with an iron carbonyl and a reducing gas
selected from the group consisting of hydrogen, carbon
monoxide, ammonia, methane and ethylene.
19. The process of claim 1 or claim 7 in which the
feed ore has been preconcentrated by a separation technique.
20. The process of claim 1 or claim 7 in which the ore
is first subjected to a magnetic separation and the resulting
non-magnetic fraction comprises the feed ore.
21. The process of claim 1 or claim 7 wherein the
mineral values are physically separated from the gangue
by a magnetic separation process.
22. The process of claim 21 wherein the magnetic
separation process is a wet magnetic separation process.
23. The process of claim 1 or claim 7 wherein the
mineral values are physically separated from the gangue
by an electrostatic technique.
24. In a process for the beneficiation of a metal sulfide
ore from gangue, excluding coal, selected from the
group consisting of galena, molybdenite, sphalerite,
bornite, cinnabar, arsenopyrite, smaltite, chalcocite,
chalcopyrite, orpiment, realgar, pentlandite, stibnite
and tetrahedrite wherein the ore is treated with an iron
containing compound under conditions which 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 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 magnetic separation between the metal sulfide
values and the gangue, the improvement for an ore in a
specific system comprising:
cotreating the ore with a reducing gas at a rate of
about 100 percent of the reactor atmosphere and
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 compound in a specific system for the
ore being treated and wherein the reducing gas
used in the cotreatment is in addition to any reducing
gas which may be produced from the metal
containing· compound treatment.
25. The process of claim 24 wherein the metal sulfide
ore is cotreated with a reducing gas selected from the
group consisting of hydrogen, carbon monoxide,ammonia,
methane and ethylene and an iron containing
compound selected from the group consisting of iron
pentacarbonyl, ferrous chloride, ferric chloride, ferrocene
and ferric acetylacetonate for a time period of
from about 0.15 to about 2 hours.
10
4,289,528
18
ture within a range of 50° C. less than the general decomposition
temperature of the ferric chloride in a
specific system for the ore being treated.
43. The process of claim 42 wherein the metal sulfide
ore is galena.
44. The process of claim 26 wherein the metal sulfide
ore is bornite.
45. The process of claim 26 wherein the metal sulfide
ore is cinnabar.
46. The process of claim 26 wherein the metal sulfide
ore is arsenopyrite.
47. The process of claim 26 wherein the metal sulfide
ore is smaltite.
48. The process of claim 26 wherein the metal sulfide
ore is chalcocite.
49. The process of claim 26 wherein the metal sulfide
ore is chalcopyrite.
50. The process of claim 26 wherein the metal sulfide
ore is orpiment.
51. The process of claim 26 wherein the metal sulfide
ore is realgar.
52. The process of claim 26 wherein the metal sulfide
ore is pentalandite.
53. The process of claim 26 wherein the metal sulfide
ore is stibnite.
54. The process of claim 26 wherein the metal sulfide
ore is tetrahedrite.
55. The process ofclaim 10 wherein the gas is employed
at a rate of at least about 10 percent of the reac-
30 tor atmosphere; the carbonyl is employed in an amount
offrom about 1 to about 50 kilograms per metric ton of
ore and the cotreatment process is carried out a temperature
within a range of 50° C. less than the general
decomposition temperature of the carbonyl in a specific
system for the ore being treated for a period of time
from about 0.15 to about 2 hours.
56. The process of claim 55 wherein the gas is employed
at a rate of about 100 percent of the reactor
atmosphere and the carbonyl is employed in an amount
of from about 2 to about 20 kilograms per metric ton of
ore.
57. The process of claim 56 wherein the carbonyl is
iron carbonyl and the cotreatment process is carried out
at a temperature within a range of 15° C. less than the
general decomposition temperaiure ofthe iron carbonyl
in the specific system for the ore being treated.
* * * * *
17
26. The process of claim 25 wherein the iron containing
compound is iron pentacarbonyl and the cotreatment
is conducted at a temperature within a range of
15° C. less than the general decomposition temperature
of the iron pentacarbonyl in a specific system for the ore 5
being treated.
27. The process of claim 26 wherein the metal sulfide
ore is galena.
28. The process of claim 26 wherein the metal sulfide
ore is molybdenite.
29. The process of claim 26 wherein the metal sulfide
ore is sphalerite.
30. The process of claim 25 wherein the reducing gas
employed is selected from the group consisting of hydrogen
and carbon monoxide and the iron containing 15
compound employed is ferrocene.
31. The process of claim 30 wherein the metal sulfide
ore is galena.
32. The process of claim 30 wherein the metalsulfide
ore is molybdenite. 20
33. The process of claim 30 wherein the metal sulfide
ore is sphalerite.
34. The process of claim 25 wherein the reducing gas
employed is selected from the group consisting of hydrogen
and carbon monoxide and the iron containing 25
compound is ferric acetylacetonate.
35. The process of claim 34 wherein the metal sulfide
ore is galena.
36. The process of claim 34 wherein the metal sulfide
ore is molybdenite.
37. The process of claim 34wherein the metal sulfide
ore is sphalerite.
38. The process of claim 25 wherein the reducing gas
is hydrogen and the iron containing compound is ferrous
chloride and the cotreatment is conducted at a 35
temperature within a range of 50° C. less than the general
decomposition temperature of the ferrous chloride
in a specific system for the ore being treated.
39. The process of claim 38 wherein the metal sulfide
~~~~ ~
40. The process of claim 38 wherein the metal sulfide
ore is molybdenite.
41. The process of claim 38 wherein the metal sulfide
ore is sphalerite.
42. The process of claim 25 whereinthe reducing gas 45
is hydrogen and the iron containing compound is ferric
chloride and the cotreatment is conducted at a tempera-
50
55
60
65