close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2125337

код для вставки
2,125,337
Patented Aug. 2, 1938
UNITED STATES PATENT ,OFFICE
2,125,337
FLOTATION REAGENTS AND LIETHOD
OF USE
Antoine M. Gaudin, Butte, Mont.
No Drawing. Application December 24, 1929,
'
Serial No. 416,291
5 Claims.
(01. 209-166)‘
As an illustration of the depressing effect of
This invention relates to the recovery of values
from ores by subjecting the same to a ?otation mercaptans upon iron minerals as compared
with the xanthates, a ?otation operation con
operation in the presence of certain reagents.
I have discovered that certain organic sub - ducted in a circuit containing pure pyrite in the
5 stances of the general formula RSH (in which R presence of 0.05 lb.- per ton of potassium ethyl
denotes a hydro-carbon radical, S-sulphur, and xanthate, recovered the entire amount of the
iron. Using the same amount of thio-beta-naph
I-I—hydrogen), such as mercaptans and thio
thol a concentrate was obtained which contained
phenols, are particularly good collectors of cop
per minerals, oxidized aswell as sulphides, as 97% of the iron. When pure chalcolcite was sub
jected to a ?otation operation under the same 10
10'- well as of the sulphides of zinc. Likewise the ox
circumstances with the above, two reagents the
idation products of these organic hydro-sul
phides such as the sulphides and di-sulphides recovery was 62% and 96% respectively. In the
are substantially as good collectors as the mer
same manner the recoveries of these minerals -
captans themselves for the. sulphide minerals
with 0.03 lb. per ton of potassium ethyl xanthate
and isoamyl mercaptan, is respectively 93% and 16
86% for the pyrite and 57% and 92% for the
chalcolcite.
Similarly, in synthetic mixtures of pyrite and
chalcolcite, xanthate favors the recovery of py
rite, while mercaptans favor the recovery of the 20
copper mineral. Upon mixtures consisting of 25
grams of minus 200 and plus 400 mesh pure py-'
only.
15
The use of these reagents in the recovery of
minerals by ?otation is of particular advantage
in that they are not good collectors for iron sul
phides such as pyrite or'pyrrhotite, and hence
their use on pyritic copper ores is particularly
valuable in that they collect the copper minerals
to the more complete exclusion of the iron min
erals than is obtained through the use of other
collectors, of which the xanthates are typical.
The ability of mercaptans to collect oxidized
25 copper minerals makes the recovery of the ox
rite, and 25 grams of the same size pure chal
colcite, the following recoveries were obtained
with amyl xanthate and amyl mercaptan, each
used in the amount of .03 lb. per ton.
idized content of sulphide ores more ei?cient
since from 1/3 to 3/; of the total copper loss in
sulphide copper ores by ?otation is due to their
oxidized content.
30
Pyrite re
Reagent
covery
Chalcolcite
- recovery _
'
The mercaptans require less alkaline circuits
than the xanthates for the securing of conditions
98
Amyl mercaptan- ................ __'.___-
82
30
Percent
' Percent
Amy] xanthate ___________________________ -
96
‘ which result in the depression of iron minerals
and therefore the use of the former in place of
xanthates effects economies~ in the use-of lime or
‘ea in
corresponding alkali.
.
The higher alkyl mercaptans, that is, those in
the series higher than ethyl mercaptan, to wit,
propyl, butyl, amyl, hexyl, heptyl, octyl, are of
particular advantage because of their greater
40
collecting ability and their lesser volatility as
compared to the mercaptans lower in series. The
lesser volatility is of prime importance from a
practical standpoint because it lessens the dis
comfort caused by the semi-poisonous vapors and
loss of reagent.
‘
- ._
I have discovered that the oxidation products
The pyrite which occurs in ores is generally
substantially less ?oatable than the pure pyrite 35
used in the above tests. This is probably due to
the presence of oxidized coatings on- its surface.
The absolute values obtained in tests with ores
are therefore not in agreement with those ob
tained with pure minerals, but the relatively 40
greater ?oatability of pyrite with xanthate and
ohalcolcite with mercaptan again manifests itself.
For instance, a copper ore containing 1.72% cop
per, largely as chalcolcitev and 4.3% iron, largely
as pyrite, was subjected to ?otation with-the 45
following reagents, with the recoveries indicated.
of the mercaptans, that is, the sulphides and di
sulphides, are substantially as good collectors for
the sulphide ores as the mercaptans themselves.
On the other hand, unlike mercaptans they do
not react with dissolved base metal salts so
that they can be used with circuits containing
various amounts of these salts without loss. In
the case of certain ores the use of sulphides and
di-sulphides makes possible a considerable saving
60
"
Lb. per
Iron re-
Copper
Reabent
ton
covery
recovery
Percent
Percent
50
0.05
72
Amy] xanthatm. ................. _-
0. 05
91
92
Amy] mercaptan .................. _ .
Ethyl xanthate _______________ __>.-.-
0. 05
74
93
81
In all of the above quoted tests a frother was.
in the alkaline reagents which otherwise are re
' used in conjunction with the various collectors,
quired to eliminate the soluble salts before using
the amount of frother being the same in each
mercaptans or other ?otation reagents, such as
case.
the xanthates.
'
,
I have also found that the mercaptans are par
55
2
2,125,337
. ticularly well suited to collect oxidized copper
The following table illustrates a ?otation op
eration conducted upon the copper-bearing sul
minerals such as malachite, azurite, cuprite and
melaconite. Thus an 80% recovery of malachite
from a 10:40 mixture ofmalachite and calcite
required 1.3 lbs. per ton isoamyl mercaptan or
phide mineral, chalcocite.
‘
Reagents
‘1.9 lbs. per ton n-butyl mercaptan, Whereas 2.0
lbs. per ton isoamyl xanthate and 4.1 lbs. per ton
n-butyl xanthate were required to give the same
recovery. Similar results were obtained with
10
azurite.
0.05 amyl merca
Recovery
percent
an _______________________ __'_ _________ _.
100
0.05 amyl mercaptan+0. 5#/'1‘ hydrated CuSO4
0.05 amyl sulphi
.
27
_______________________ __'__
_
0.05 arnyl sulph1de+0.25#/T hydrated CuSOi
A particularly good ?otation of oxidized cop
per minerals by mercaptans is of interest in the
?otation of sulphide ores since the. greater por
(01.05 amyl
s
[J
100
_
de ______________________ __
__
_
100
.05 amyl disulphide+0.25#/T hydrated OuSOl ________ _.
tion of the copper loss in such minerals ‘is due
Similarly with a' copper ore in which'the cop
15 to the presence of the values in oxidized form.
per existed as chalcopyrite and chalcocite, to
gether with some copper in solution, the follow
ing results were obtained.
A sulphide copper ore carrying chalcopyrite as
the principal copper mineral, assaying 1.95%
10
99
15
copper, of which 0.17% was oxidized copper,
gave a tailing of 0.26% copper when ?oated with
0.10 lb. per ton sodium ethyl xanthate. The
Amount of Recovery
Reagent
reagent
percent
20
copper content of the tailing was reduced to
0.12% when isoamyl mercaptan was substituted
pound for pound for xanthate.
Benzyl mercaptan; _______________________ _.
Benzyl mercaptan _______ _ .
'
The following data illustrates the advantage
+Lime _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ , _
_ _ _ _ _ _ . __
Benzyl disulphide _________________________ _ _
0. 10
40
0. l0
________ _ _
4.
0
84
0. 10
87
25 secured from the use of higher mercaptans,
25
showing the amount of reagent in pounds per -
I have furtherdiscovered that mercaptans or
thiophenols are much more e?icient as ?otation
reagents for sulphide zinc-bearing ores than
ton required to ?oat 80% of the ore indicated.
.
30
Reagent
Ethyl mercaptan .................. _.
35
10:40 mixture
1215333380
n-Propyl mercaptan...
_______ _ .
n-Butyl mercaptan____
____
.
plus 600 mesh
calcite
malachite and
calcite
.
Isoamyl mercaptan ________________ _ _
xanthates.
of minus 100
mesh chal_
0. 14
______________ __
0. 06
2. 8
0. 035
1. 9
0. 02
1. 3
_
In the above experiments the mercaptans or
thioalcohols were added to the ?otation cell as
40 alcoholic solutions. Obviously the reagent may
be added to the ball mill prior to ?otation or to
the ?otation cell ‘or to some conditioning or
that the copper activated sphalerite is particu
larly amenable to ?otation by reagents which
are well suited to the ?otation of cupriferous
ores. Among these reagents are the organic hy 40
drosulphides and their oxidation products as
above set forth.
emulsifying tank between the grinding and ?ota- .
tion stages. Reagent additions may be made in
45 the solid or liquid form or' in solutions in some
inert solvent such as methyl alcohol, an amine,
a phenolic compound or one of the usual ?ota
tion oils, such as pine oils. The greater solu
bility of mercaptans as compared with .thio
50 phenols is of distinct advantage in this particular.
The use of the higher hydrosulphides is ad
vantageous as compared with the use of the
lower hydrosulphides in that the. former are con
siderably less volatile than the latter and this,
55 together with the fact that smaller amounts of
the higher hydrosulphides are required, minimizes
the danger of the reagent occurring in the air
.
It has been known for some time that the 30
use of soluble copper salts makes zinc sulphides
more amenable to ?otation reagents. I have
found that the bene?cial effects of copper salts
in the ?otation of zinc sulphide is due to the
formation of a thin coating of copper sulphide 35
upon the surface of the mineral and furthermore
I have found that the use of mercaptans or _
thiophenols in ?oating copperractivated sphal
erite makes possible the ?oatability thereof over a 45
substantially-extending alkaline range, which is
not secured by the use of xanthates . Thus, with
a certain amount of xanthate‘, material depres
sion results at pH 12, whereas such an e?ect
doesrnot manifest itself when using the same 50
amount of- the corresponding mercaptan until
about pH 13. This discovery is 'of practical value
in the treating of iron-bearing zinc ores or pyritic
copper ores. It is illustrated in the following
table:
55
Recoveries.
to a dangerous concentration.
Reagents
Further, I have discovered that the oxidation
60 products ofv organic hydrosulphides, especially
sulphides and disulphides, are substantially as
good collectors for sulphide minerals as are the
65
Zn
0 .10 K. ethyl xanthate _______ __
2 . CaO __________________ _>..._
by organic'sulphides and disulphides.
0.
0.
salts. Flotation of sulphide ores containing solu
ble salts is therefore prohibited if organic hydro
70 sulphides are used as reagents unless the pulp is
?rst freed of the soluble salts by the addition of
a precipitation agent or other metal ion abstract
ing agent.- The use of sulphides ‘or disulphides
of the above type obviatesthe necessity and cost
of adding such a precipitation agent.
Fe
0 .75#/T CuSO4, :- 11,0 ______________ __. .... __
hydrosulphides themselves. Copper-bearing sul
phide minerals in particular are readily ?oated
Unlike organic hydrosulphides, organic sul
phides do not react with dissolved base-metal
percent
65
2
0 .m/r
amyl
011804,
mercaptan
5 mo ____________
0 .08
4.0 0:10
70
' A great many organic compounds of the gen
eral-formula RSH are known and probably, many '
others exist which have not been speci?cally
identi?ed. I have found that ethyl, propyl, butyl,
amylphexyl and heptyl mercaptans as well as 75
3
2,125,387
their oxidation products, are particularly e?lcient
for the purpose ‘set forth. Broadly speaking, the
reactions of these various compounds are similar
of an alkyl mercaptan higher in the series than
ethyl mercaptan.
,
‘
3. A method of recovering oxidized copper ore
values from the gangues in crude copper ore,
and hence they are to be construedlin this appli
cation as being typical and I do not wish to be I which consists in subjecting the crude ore' to a
froth ?otation operation in the presence of amyl
limited speci?cally to any of the particular re
agents named, but the claims appended hereto
should be construed broadly.
What I claim is:
1. A method of recovering values from oxidized
10
ores which consists in subjecting the same to a
?otation operation in the presence of an alkyl
mercaptan higher in the series than ethyl mer
captan.
15
2. A method of recovering values from oxidized
copper and zinc ores‘ which consists in subjecting
the same to a-?otation operation in the presence
mercaptan.
4. A method of recovering values from ores
containing both sul?des and oxidized products
of the same metal which comprises subjecting 10
the same to a ?otation operation in the presence
of an alkyl mercaptan higher in the series than
ethyl inercaptan.
5. A method according to claim 4 in which the
ore contains copper sulfide and oxidized copper 15
compounds. _
ANTOINE M. GAUDIN.
Документ
Категория
Без категории
Просмотров
0
Размер файла
346 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа