Patented
1,788,332
6, 1931
UNITED ' STATES
PATENT OFFICE
wrrnnnn scan-Ea, or BOGHUM, enanm
TREATMENT OF COMPLEX OBES BY FLOTAT'ION
No Drawing. Application ?led September 148, 1929, Serial No. 898,584, and in Germany September 22, 1928.
‘ The invention relates to the treatment of
In numerous cases it is of advantage to use
complex ores containing sul?des of zinc in hyposul?tes in the resence of other reagents
the presence of other metalliferous sul?des which liberate '0 -ions or H-ions in the
such as lead or copper sul?des where the col
pulp ' it may be useful to add these reagents
lective a?inity of oils and similar substances ,toget er with the hyposul?tes or before or
is utilized to make a separation, especially to afterwards. The hydroxyl ions may be fur
the so called froth ?otation process in which nished by bases or by salts having an alkaline
5
the substances adhering to the oil are sepa
rated from the pul by the use of a gas (such
10 as air) in form 0 a froth. In these proc
esses it is known to in?uence the ?otative
ualities by the use of reagents in addition to
t e - oils.
These known reagents, such as
. cyanide of otassium, sul?des and sul?tes of
15 alkali, are
own to influence the ?otative
reaction or by any compounds either organic .
or inorganic which in the process give rise
toan alkaline reaction. The hydrogen ions
may be furnished by acids or salts having an
acid reaction or by compounds either or
ganic or' inorganic which in the process give
rise to an acid reaction. When the reagents
which liberate hydroxyl or hydrogen ions
are added after the treatment of the pulp
with the hydrosul?tes, they assist in the re
activating of the blende, and allow the ?ota
qualities, so that for instance it is possible
to ?rst separate the lead- or copper sul?de _in
the froth and to separate subsequently after
having compensated the action of these re tion of the zinc sul?de previously separated
20 agents, and adding other reagents, the zinc from the pulp.
,
sul?des in the froth. The action of the re ' The principal advantage of the hyposul
agents, having the eifect to keep down cer ?tes over other known rea cuts of the de
tain sul?des, is commonly known as depress pressing type, consists in t e fact that the
ing action While those reagents which com
yposul?tes do not only depress the ?otation
‘25 pensate the action of the reagents of the of the zinc mineral, but at the same time do
?rst-mentioned‘kind, and effect the separa materially in?uence the ?otative qualities of
tion of the depressed mineral, are called for instance the lead and copper sul?des.
anti-depressing rea ents.
They have the further advantage that they
It has been foun that a very effective de are practically non-poisonous as contrasted to
30 pressing action on the zinc sul?des and at the some other reagents used in the art. Some
same time an activating effect on the copper examples are given herewith to demonstrate
35
or lead sul?des, is produced by the add1t1on thee?ect of the hyposul?tes in comparison
of salts of the “hyposulfurous acid”, that is with cyanide of alkali frequently used.
of hyposul?tes of the formula:
Ewample N0. 1
g; 8104
55
60
85
75
80
85
100 gr. of a lead-zinc complex ore with
quartzitic gangue were ground to 100 mesh
in which formula R1 and R2 may be either ?neness and diluted with four parts of water.
% gr. of a hyposul?te of the following for
the same or different metals.
These hyposul?tes are 'to be clearly dis mula (Na2Zn)‘(S2O4) 2 were added and 1.5 gr.
' tinguished from the thiosulfates of the sodium silicate, furnishing hydroxyl ions, and
formula R2820, which are sometimes er several drops of-ahard-wood tar oil and a
40
roneously' called also hyposul?tes. The pine oil were added. Then separation was
complex hyposul?tes, especially those in made by producing a froth through the intro
45 which R1 is an alkali metal and R2 a base duction of air under pressure and the follow
metal, are generally more e?ective as de
pressors of the zinc mineral while the simple
salts in which R1 and R2 are the same metals,
are generally more e?ective as activator of
50 the lead and copper minerals.
95
ing products were obtained:
3.5 weight % lead-concentrate with- 71.4% Pb 5.4% Zn
96.5 weight % zinc residues with.._-..
100.0 weight % heads with ________ __
0.6% Pb 9.4% Zn
3.1% Pb
9.2% Zn
The zinc residues were not further treated
pi 00
.2
1,788,382
metal salt of the “hyposulfurous acid” of the
vating action of the hyposul?tes on the lead, formula H2S2O4 and substances containing
hydroxyl ions, and subjecting the ore pulp
and the depressing action on the zinc.
A parallel test was made in exactly the to ?otation whereby the zinc sul?des to be
as the test should only demonstrate the acti
same manner and with exactly the same
amount of ore but using 0.3 gr. sodium cya
sfepalrated are prevented from adhering to the
nide and 0.5 gr. zinc sulfate instead of the.
4. In the froth ?otation process of treating
rot 1.
70
hyposul?te. The following products were ?nely divided zinc sul?des ore in the presence
obtained:
3.7 weight % lend concentrate with__G0.5% Pb 8.5% Zn
06.3 weight % zinc residues with__.___ 0.8% Pb 9.2% Zn
of other metalliferous ores to effect a separa
tion of the zinc sul?de mineral from the other "
minerals which comprises treating the ores,
iEiE -\;e'ii;hi_§i,—n;;l1§:vn1i_l___' ____ __ 3.0% Pb‘ 0.2% Zn with a ?otation solution containing a complex
15
metal salt of the “hyposulfurous acid” of the
[fa-ample N0. 53
formula H2S2O4 and substances containing
A very complex and ?nely disseminated hydroxyl ions, and subjecting the ore pulp to
lead-zinc ore was ground to all-below 200 ?otation'whereby the zinc sul?des to be sepa
mesh and a test with 1000 gr. of this ore di rated are prevented from adhering to the
80
luted in 4 parts of water was made. 0.6 gr. froth.
Na-2S2O4 and 2 gr. NagsiOa, furnishing hy
20
5. The step in the froth ?otation process of
droxyl ions, were added and also some drops treating ?nely divided zinc sul?des ore in the
of pine oil creosote and zanthatc. The follow presence of other metalliferous ores to e?ect
a separation of the zinc sul?de mineral from
ing~products were obtained:
the other minerals which comprises treating
9.5 weight % loud concentrate with_57.-“\% Pb
9.1 weight % lend iuiddlings wlth__25.2% P1)
81.4 weight % zinc residues witl1____ 3.8% Pb
the ores with a ?otation solution containing a
metal salt of the “hyposulfurous acid” of the
formula H2820.‘ and substances containing
A parallel test was made in exactly the hydroxyl ions, whereby the zinc sul?des to be
100.0 weight % heads .with ________ _..10.9% Pb
30
40
17.8% Zn
00
same manner as before but using instead of separated from the ore are prevented from
the hyposul?te, 0.5 gr. sodium carbonate and adhering to the froth and thereafter adding
0.3 gr. cyanide of sodium and 0.4 gr. zinc sul to the solution a substance having hydrogen
fate. The following products were obtained: ions whereby the ?otation of the zinc sul?des
7.0 weight % lead concentraie with_2S.8% Pb
14.0 weight '72; lend middlings with__211.9‘/0 Pl)
78.4 weight % zine residues with____ 7.2% Pb
17.9% Zn
18.5% Zn
17.7% Zn
100.0 weight % heads with ________ _._10.9% Pb
17.8% Zn
is permitted.
6. The step in the froth ?otation process of
treating ?nely divided zinc sul?de ore in the
presence of other metalliferous ores to effect 100
Having thus described my invention what a separation of the zinc sul?de mineral from
the other minerals which comprises treating
I claim to protect is:
‘
1. The step in the froth ?otation process of the ores with a ?otation solution containing a
treating ?nely divided zinc sul?des ore in the complex metal salt of the “hyposulfurous
presence of other metalliferous ores to e?'ect acid” of the formula H2820. and substances
a separation of the zinc sul?de mineral from containing hydroxyl ions and subjecting the
the other minerals which comprises treating ore pulp to ?otation, whereby the zinc sul?des
the ores with a ?otation solution containing a to be separated from the ore are prevented
metal salt of the “hyposulfurous acid” of the from adhering to the froth and thereafter
formula HZSQO.a and subjecting the ore pulp adding to the solution a substance having hy
to ?otation whereby the zinc sul?des to be drogen ions whereby the ?otation of the zinc
iepalll'ated are prevented from. adhering to the sul?de is. permitted.
rot
50
85
110
' DR. WILHELM SCI-IAFER.
.
2. The step in the froth ?otation process of
treating ?nely divided zinc sul?des ore in the
115
presence of other metalliferous ores to effect
a separation of the zinc sul?de mineral from
the other minerals which comprises treating
the ores with a ?otation solution containing a
complex metal salt of the “hyposulfurous
acid” of the formula H2820” and subjecting
the ore pulp to ?otation whereby the zinc sul
?des to be separated are prevented from ad
hering to the froth.
00
'
3. The step in the froth ?otation process of
125
' treating ?nely divided zinc sul?des ore in the
presence of other metalliferous ores to effect
a separation of the zinc sul?de mineral from
the other minerals which comprises treating
65
the ores with a ?otation solution containing a
130