4,289,528 Process for beneficiating sulfide ores

Patent Number/Link:

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

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

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

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

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

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-

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

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

4,289,528

TABLE 3-continued

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

None

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)

Gas

None

Product

Magnetic

·Sphaletite

Weight· Grade· Di.tr.

.(%) • (%) . (%).

0.54 10.23.1

4,289,528

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

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

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

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.

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.

4,289,528

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.

* * * * *

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-