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Experimental work on the flotation of chrysocolla
Item Type text; Thesis-Reproduction (electronic)
Authors Rutledge, Franklin Allen
Publisher The University of Arizona.
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Arizona.Further transmission, reproduction or presentation (such
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Link to Item http://hdl.handle.net/10150/553452
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EXPERIlffiMTAL WORK ON THE FLOTATION OF CHRYSOGOLLA
t»y
submitted to the faculty of the
the requirements for the 1
1959
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- v ‘ :*f. * * ■
-
i£ 9 7 9 /9 9 3 7
' ‘ ̂ —PREFACE
The writer wishes to give grateful acknowledgment to Mr. F. S.
Wartman, Associate Metallurgist, Southwest Experiment Station,
United States Bureau of Mines, under whose supervision this work
has been done, and to Dr. T. G. Chapman for his aid and advice in
the preparation of this thesis.
The writer also wishes to give acknowledgment to the Arizona
Bureau of Mines for the fellowship that made this research
possible.
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ii
CONTENTS •i s m
Chapter I - Introduction .......................... 1Chapter II
- Materials. apparatus, and procedure#. . 4
Materials . . . .......... . . . . . ........ 4Determination of
sulphur. . . . . . . . . . . . 5Flotation procedure
........................... 6Copper analysis . . . . . . . . . . .
........ 7Determination of xanthate . . . . ............
7Determination of pH with a glass bulb eleotrede 8
Chapter III - Experimental work on the abstractionof soluble
sulphur by chryaocolla .............. 9
Interpretation of results . . . . . . . . . . . 11Chapter IV -
Experimental work on flotation. . . . . 15
Flotation after abstraction of soluble sulphurby solids in the
charge................ 15
Interpretation of results................ ISEffect of method of
agitation on flotation
results. . . . .............. . . . . . . . 18Interpretation of
results. .............. 19
Effect of copper sulfate on filming of chryso-oolla with sodium
sulfide.............. 19
Interpretation of results............... 20Denver Equipment
Company reagent "CP Flotation
O i l " ....................................... 22Interpretation
of results................ 25
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iii
Chapter V - Abstraction of zamthat#. Interpretation of results .
. .Pine charcoal . . . ..........
Interpretation of results. Abstractions by various minerals
Interpretation of results.Copper minerals . . ..........
Interpretation of results. Chapter 71 - Conclusions . . . . .
.
*8P2930303134353738
-
17
TABLES
Table I - Abstraction of soluble sulphur byehrysooolla . . . .
........ . . . . . 12
Table II - Flotation with sulfide filming data . • 17Table III -
Effect of degree of agitation . . . . . 18Table Ilia - Reagents
used ....................... 19Table 17 - Results of tests
employing copper
sulphate. . ........................... 21Table V - Denver
Equipment Company reagent "CP”
flotation oil , ............ 24Table 71 - Adsorption of xanthate
by 1 gram of
Wttchar. ......................... 29Table 711 - Adsorption of
xanthate by 1 gram of
pine charcoal . . . . . . . . . . . . . 30Table Till -
Adsorption of xanthate by 50 grams of
gangue No. 2. . . . . . . . . . . . . . 32Table IX - Adsorption
of xanthate by 10 grams of
gangue No. 3..................... 33Table X - Adsorption of
xanthate by 10 grams of
quartz.......... .. ............ 33Table XI - Adsorption of
xanthate by 5 grams of
kaolin. . . . . . . . . . . . . . . . . 33Table XII -
Abstraction of xanthate by 2 grams of
ehrysooolla................... 35Table XIII - Abstraction of
xanthate by 2 grams of
chalcooite. .............. . . . . . . 36Table XI7 - Abstraction
of xanthate by 2 grams of ;
Miami slime ........ .. . 36
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. FIGURES
ES&eFigure 1 - Adsorption of xantMte by 1 gram of Nuohar . .
89a
, ' ■ ■ ' '
Figure 2 - Adsorption of xanthate by 1 gram of pinecharcoal . .
. . . . . . . . . . . . . . . . . 30a
Figure 3 — Adsorption of xanthate by 1 gram of gangueNo. 2.
............................... .. 33a
Figure 4 - Adsorption of xanthate by 1 gram of gangue• No* 3* ■
•
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1
processes has reached a high degree of proficiency, but
floated, the carbonates to a leaser extent, and the silicate,
chrysooolla, is the most difficult of all to float. The presence of
chrysooolla in many of the so-called "mixed ore" bodies of the
Southwest and the difficulty of concentrating it by current
flotation methods led the United
The first experimental work was done by Leininger^ in 1937 with
fatty acids and soaps as promoters. It was found that free fatty
acids did not give sufficient selectivity to yield satisfactory
separations of the ohrysocolla and gangue. Satisfactory recoveries
of chrysooolla were made using soap as a promoter,** 2* but the
selectivity of the promoter was low and the reagent consumption
excessive.
tion of Chrysooolla, Part II, Thesis University of Arizona 1937,
p. 3.(2) Ibid., p. 18.
-
Further work by Faust ̂3 4 5 6 ̂ in 1938 showed that successful
flotation of the ehrysocolla could be obtained when using xanthate
and a modified soap reagent, DLT-698, "An aoylated condensation
product of a fatty acid with an alky- lol amine",^ without
resorting to preliminary sulfidizlng. His results indicated that
fairly pure ehrysocolla could be satisfactorily sulfidlzed by the
use of sodium sulfide together with an ammonium salt or by hydrogen
sulfide alone.A satisfactory recovery was obtained on a synthetic
ohryso- oolla-pegmatlte mixture using a sulfidizlng reagent and the
usual sulfide promoters. The recovery, when this procedure was
followed on a mixed ore from Miami, was not satisfactory
The results of Faust's work are in disagreement with (5)Gaudln
who states' that the sulfidizlng of copper sili
cate is practically inposslble.According to experiments which
included work on oxi-
f SiSized copper minerals reported by Anderson,' the floata-
bility of copper minerals after sulfidizlng, if floated with the
same collectors as are used in the flotation of sulfide minerals,
is slightly less than the floatability of the same minerals without
sulfidizlng.
(3) Faust, W. A., Sulfide Filming and Flotation of Ohryso-
colla, Thesis University of Arizona, 1938, p. 29.(4) Wartaan, F.
3*, Associate Metallurgist, U. S. Bureau of Mines, Southwest
Experiment Station, Tucson, Arizona, Personal communication.(5)
Gaudln, A. M., Flotation, McGraw-Hill Book Co., Hew York, 1932, p.
307-308.(6) Ibid., p. 308.
-
Rickard and Ralston 1 state that although, ohrysooolla will
blacken when treated with a sulfidizing reagent, it still resists
flotation, possibly because it presents a silicate rather than a
sulfide surface even after sulfidiz- ing.
Fahrenwald^ gives examples of improved recoveries with the use
of coal tar or shale tar alone or in conjunction with xanthate.
The experimental work described in this paper is
a(9)continuation of the work started by Faust.1 1 The work 7 8
*
(7)
(7) Rickard, T. A., and Ralston, 0. C., Flotation, McGraw- Hill
Book Go., New York, 1917, p. 375.(8) Fahremmld, A. W., Ore Dressing
Benefits by Research, Engineering and Mining Journal, Vol. 139, No.
S, Feb., 1938,?9) Faust, W, A., Sulfide Filming and Flotation of
Ohryso- oolla. Thesis University of Arizona, 1938.
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CHAPTER II - MATERIALS, APPARATUS, AND PROCEDURES
Materials
The ohryaoeolla used In preparing the synthetic mixture was
obtained from the Inspiration Consolidated Copper Company. Two
different lots, ground to minus 100-mesh were used, one containing
28.S and the other 17,68 per cent of copper.
Quartz-feldspar minerals, in the form of a pegmatite from the
Oracle district of Arizona, were used for the gan- gue. This
pegmatite was ground to minus 100-mesh, and 66 per cent of the
product was minus 200-mesh. Three lots numbered 1 to 3 were used.
The three lots were obtained from the same locality, and varied
chiefly in the amount of oxidation. The first lot was a light
colored pegmatite that showed little signs of oxidation; the second
was badly decomposed, and when ground was a pale tan in color; and
the third was very much like the first.
The above materials were ground in an Abbe* porcelain laboratory
mill with silllmanite pebbles thus eliminating the deleterious
effect of iron. According to P. A. Bird,*10*
(10) Bird, F. A., Fundamentals in the Flotation of Sulphi- dized
Oxidized Ores, E. & M. J., Vol. 125, p. 652.
-
#
*
cent of copper and 98 parts of one of the described pegmatites.
The resulting mixture contained 0.59 per cent of copper, for some
of the later tests, a mixture of 5 parts of the second lot of
ohryeocolla and 97 parts of gangue was
iaetrio comparison of the amount of lead sulfide formed upon the
addition of lead acetate. A sample of 20 e.e. of the filtrate from
the sulfidizing test was diluted to 100 c.o. with distilled water,
and 2 o.o. of a saturated solution of gum acacia added. The
solution was then placed in a flat bottomed glass tube through
which the light from a 6-volt bulb passed. The intensity of the
light passing through the solution was measured by a photo-electric
cell which in turn actuated a galvanometer. The reading from the
galvanometer was compared to a curve plotted for known
concentrations, and this gave the concentration of sulphur
-
of by adjusting a rheostat in the 6-volt light circuit and in
this manner the amount of light passing through the solution before
the formation of the lead sulphide was kept constant. The pH value
of the filtrate was determined by LaMotte comparators.
The procedure followed in all flotation tests was the same as
used for previous work on this problem. A 100- gram sample of the
ohrysoeolla-pegmatite mixture was placed in a 100-gram capacity
flotation machine of the mechanical sub-aeration type with 100 e.e.
of distilled water, and the resulting pulp agitated for five
minutes to ensure proper wetting. After the reagents were added,
the pulp was conditioned for 10 minutes before the flotation period
was started. The total time of flotation was 15 minutes with the
pulp level maintained at such a height that the froth overflowed by
gravity. The pH value of the water in the tailing pulp was
determined by LaMotte comparators.
The concentrate and tailing were recovered by filtration using a
suction filter, and after washing with a small amount of ethyl
alcohol^ placed in beakers and dried. The residues were then
weighed, and samples taken for analysis.
-
A 0.5-gram sanple of the concentrate and a 5-gram sample of the
tailing were taken for analysis. The samples were decomposed with
10 e.o. of concentrated nitric acid on a hot plate, and after
dilution, filtered and 5 c.c. of concentrated sulfuric acid added
to the filtrate. The copper was deposited on rotating platinum
electrodes using 1.4 amperes.
The abstractions of xanthate by the gangue and the ohrysooolla
were found by determining the amount of xanthate left in solution
after agitation and filtration.The procedure used was as follows. A
50-gram sample of the gangue or a 2-gram sacqple of the ohrysooolla
was placed la a 500 c.c. flask with varying amounts of potassium
ethyl xanthate and sufficient distilled water to make 150 c.c.
solution, and agitated for 15 minutes. The pulp was then filtered,
and a 100 c.c. sample of the filtrate used for determination of the
residual xanthate. The starch-iodine titration for xanthate as
outlined by Keffer*11 ̂was employed using a 0.10 H iodine solution
of which 1 c.c. was equal to 1.6 mg. of potassium xanthate.
(11) Keffer, Robert, Methods in non-ferrous Metallurgical
Analysis, McGraw-Hill Book Co., New York, 1928, p. 307-308.
-
definite pH before the start of the test, a glass bulb electrode
was used to determine the hydrogen ion concentration. The reading
from the voltmeter in millivolts was compared to the curve for
known standard solutions and gave the pH of the solution. Thus the
pH of soluti
-
Since the objective, at the start of the experimental work, was
to continue the work of Faust, the writer started
The object of the experimental work of tests 1 to SB inclusive
was to determine the distribution of sulphur, added as a part of
the sulfidizing reagent, in the ore pulp constituents after 10
minutes of agitation. The difference between the sulphur added and
the amount left in the water was assumed to be the amount
abstracted by the solids.
The procedure used was as follows. A aaa#le of ohry- sooolla
weighing 2 grams was placed in a stoppered flask with 300 o.o. of
distilled water. These amounts of ehry- sooolla and water were
equal to the amounts used in later flotation tests made in the
100-gram capacity flotation ceU. After being agitated for 5 minutes
to permit wetting of the ehrysooolla, the sulfidizing reagent,
either sodium sulfide or hydrogen sulfide, and any other reagents
used were added, and the pulp further agitated for 10 minutes. The
mixture m s then filtered, and the pH and amount of
-
aulphur contained in the filtrate determined by the methods
outlined in chapter II.
Preliminary blank tests on sodium sulfide solutions without the
addition of any solid showed that no appreciable consumption of
sodium sulfide occurred by oxidation under the conditions of
agitation employed. The results of further tests showed that this
reagent was not abstracted from solution by adsorption by the
filter paper during filtration.
Chemically pure hydrous sodium sulfide (MagS’SHgO) was used in
tests 1 to 24 inclusive, although the reagent quantities are given
in terms of the anhydrous salt (Ha2S) for tests 14 to 24 inclusive.
The results of Faust*3 work showed that ammonium sulfate promoted
the activity of sodium sulfide; and varying amounts of this reagent
were therefore added in most of these tests, in order to confirm
Faust*s conclusions, and also to determine the optimum amount of
ammonium sulfate to add for the purpose required. The experimental
results of tests 1 to 24 inclusive with sodium sulfide are given in
table I.
Hydrogen sulfide was used as the sulfidizing reagent in tests 25
to 28 inclusive. The hydrogen sulfide was prepared by bubbling
washed hydrogen sulfide gas through 100 c.c. of distilled water for
30 minutes. The sulphur content of the resulting solution was then
determined by the color-
-10-
-
sodium sulfide given In table I, the conclusions which follow
were indicated:
(1) When sodium sulfide was used without any otherreagent for
promotion of activity, 75 per cent of the sulphur was abstracted by
the solids of the charge when using 0.50 pound per ton of hydrous
sodium sulfide and only 32 per cent was abstracted when 0.50 pound
per ton of the anhydrous sodium sulfide was used. j
(2) The pH value of the solution after sulfldizing increased as
the amount of sodium sulfide added to the charge increased as would
be expected.
(3) When ammonium sulfate was used to promote the activity of
the sodium sulfide, the abstraction of the sul phur by the charge
increased until with 0.75 pound per ton of ammonium salt and 0.50
pound per ton of hydrous sodium sulfide 100 per cent abstraction
was obtained by ohryso- oolla. However, if 0.50 pound per ton of
anhydrous sodium sulfide was used, 1.25 pounds per ton of ammonium
sulfate was found to be necessary to obtain 100 per cent
abstraction.
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T*ble X - Abstraction of Soluble Sulphur by Chrysooolla
Sulfidizing Reagent
K I MPounds per ton of solids
Conditioning Haa6entPounds : foot-:abstracted byK I M : per ton
:notes): charge
sof solids: t
pH of *: filtrate ;
I T T W omixtureacid.
of ohrysooolia; containing 2 grams of
(2) 98 ohrysooolia grams (ST 1C of gangue;
of a synthetic (4) plus sulphuric
-
as-
by chryaocolla with 0.50 and 0.95 pound per ton of hydrous
sodium sulfide and ammonium sulfate respectively, only 54 per cent
of the sulphur was abstracted by the solids of the charge when
gangue minerals were substituted for the ehrysoeeU*.
(5) The addition of sufficient sulphuric acid to form ammonium
acid sulfate lowered the amount of ammonium sulfate found necessary
to obtain 100 per cent abstraction of the sulphur by any of the
solids used.
(6) The writer found as claimed by Faust that the addition of
ammonium sulfate improved the activity of sodium sulfide. However,
a larger amount of ammonium salt than that reported by Faust was
found to be necessary to obtain 100 per cent abstraction of the
sulphur, in that 1.85 instead of 0.75 pounds per ton were required
for 0.50 pound per ton of anhydrous sodium sulfide.
given in table X, the additional conclusions which follow are
given.
(7) Abstractions of 100 per cent of the sulphur by chryaocolla
were obtained when using 0.85, 0.50, or 1.00 pound of hydrogen
sulfide per ton of solids. Abstractions of hydrogen sulfide by the
ohrysooolla when amounts of
-
-14-
hydrogen sulfide greater than 1.00 pound per ton of solids were
used were not determined.
(8) The pH value of the resulting solution was lower than when
sodium sulfide was used as the sulfidlzlng reagent as would be
expected.
m-
-
-15-
GHAPT1R IT
Flotation
Following tests on the abstraction of solublesulphur by
chrysooolla, attempts were made to sulfidize ehrysooolla contained
In a synthetic mixture of chryso- oolla and gangue minerals. This
was followed by tests to determine the floatability of the
chrysooolla after the sulfidizing treatment. These tests are
numbered 50 to 33 inclusive, and the procedure for the flotation
tests as outlined in chapter II was followed.
Preliminary tests indicated that chrysooolla did not tend to
float if the pH value was high. In all these tests the chrysooolla
did not tend to concentrate in the froth, but rather to form a
layer at the pulp-froth interface even when an excessive amount of
reagent was used to promote a viscous froth. For this reason, the
concentrate was removed by allowing this layer of ehrysoeoHa to
form at the pulp-froth interface; and by raising the pulp level
permit the ehrysooolla to overflow the lip of the cell.
Test 29 was made to determine the floatability of chrysooolla
with pine oil and xanthate reagents for comparison with the
floatability of chrysooolla after
-
Bulfidizing, with the same floatation reagents. The results of
tests 29 to 53 inclusive are given in table II.
(1) In test 29 the extraction when using 0.20 and 0.10 pound per
ton of potassium amyl xanthate and QNS pine oil Ho. 5 respectively
was 48.1 per cent of the total copper. As shown in table II, this
was a slightly higher extraction than that obtained in test 30
using sulfidlzing, which was 43.0 per cent of the copper.
(2) The use of Tarol Ho. 1, a pine reagent frother, in tests 31
and 52 yielded extractions as high as 89 per cent of the total
copper. The Hercules Powder Company state that this reagent acts as
a promoter for some seal- oxidized minerals.
(5) An extraction of 99 per cent was obtained in test 33 when a
similar frother, Tarol Ho. 2, vras used without the addition of
another pine oil.
(4) The low contents of copper in the flotation froths produced
in these tests should be especially mentioned.The highest grade
concentrate was produced in test 31 and contained 4.64 per cent of
copper. The average grade for all the tests in this series was
about 3 per cent of cop-
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Table II - flotation with Sulfide Filming Data
Reagents, lbs. per ton of solids^3)after
SI
m
33
s: % wage *0.50. .*(m4)2S04 :0.75(2)t<
NagS 50.50. .sGRS Ho. 5{HH4)sS04 $0.75(2):Tarol Ho.l
Na23 :0.50 :(RIS Ho. 5(HH4)^04 $0.75(2) ifarol Ho.l
Na2S $0.50 :(HH4 ) p 04 $0.75(2) $Tarol Ho.2
Weight of -per oent:Extrac-: products, grams$copper $ tion,
Oonoen-: Tail- :In oon-$ per
0.10 1t 8.0 $ 12.78 : 87.22$3 2.12
3S’ 48.1
S’1
$ $ s f t 8$ 1 3 t
0.10 $ 0.2 3 11.02 : 88.98 S’ 1.92 $ 43.0 3$ s : 3 3 3-
0.20 s 3 3 3a.so s 7.5 3 10.80 f 88.98 3 4.64 3 89.0 3
t .1 .1 I 3 8-0.20 3 1: r0.25 7.4 : 12.98 $ 97.02 : 3.76 3 85.0
i
1 3 S’ $ t1 i 3 i-0.40 $ 7.2 $ 23.30 ! 76.70 3 2.00 3 99.0 *
: : ; : : Tl:
c ^ s .h s .......
-
Oaudln112* states that formerly the substantial conditioning of
the pulp with sodium sulfide before flotation had been considered
necessary, but lately attention hasbeen given to the suggestion
that the sulfide film formed is abraded or oxidized during the
latter part of the agitation period. A series of tests, numbered 34
to 37 inclusive, m s made to compare high degree agitation in a
flotation cell with low degree agitation in a beaker to determine
if the degree of agitation was detrimental to the procedure.The
results of these tests are given in table III, while the reagents
used are shown in table XXXa.
. ' : .. ".r,. :Table III - Effect of Degree of Agitation (IS)
*
: : Method : Weight ot :Per cent :s Test s • of : products,
grams ; Conner in:: No. :Agitation: Conoen- :TaDllngI : Conoen- i:
: : trates : (a) : trntes :
SEtraoT”.^tton,
1 =4 ! Beaker :: 3.48 : 96.58 { 7.74 { 50 *! 35 : Cell :2 5.08 :
94.98 ! 9.46 : 84 :; 36 ; Beaker 22 8.34 ! 97.66 ! 4.88 : 56 :: 37
; Cell 22 3.88 I 96.78 { 10.70 : 78 •;(a) By difference
(IS) Oaudin, A. M., Flotation, McGraw-Hill Book Co.,New York,
193B, p. 301.
-
Table Ilia - Reagents Used
: :_____Reagents used, pounds per ton of solids_____:: h o . : :
(NH4)2S04:x t h t : QNS : Tarol :i : f»> ; : 5 : Ho. 1 ;[ 34 ;
0.35 : 0.50 : 0.20 ; 0.10 : 0.05 *
I 55 : o.35 ; o.so : 0.20 * 0.10 • o.os •
; 36 : 0.50 ; 0.75 : 0.20 : 0.10 : o.os !1 * • * # *•; 37 ; 0.50
; 0.75 : 0.20 ; 0.10 \ 0.05 ;(a)Sufficient sulphuric aoid added to
form
sold sulfate
The results given in table III show that higher extractions were
obtained, 72 and 84 per cents, when the vigorous agitation of the
flotation cell was employed, com,
a beaker, and these results indicate that such vigorous
agitation of the pulp was not harmful to the procedure.
©rous agitation was not harmful, it was considered possible that
the chrysocolla was not being properly filmed with thesulfide
eoatlag.
-
Copper sulfate was added In tests 38 to 42 Inclusive to test the
possibility of its adsorption by the ohryso- eolla, and the further
possibility that this adsorption might increase the sulfldizlng and
therefore the preferential floatability of the ohrysooolla as
compared to the gangue minerals.
Preliminary flotation tests with copper sulfate, xan- thate, and
pine oil did not give any higher extraction than with xanthate and
pine oil used without copper sulfate.
The procedure used for this series of tests was the same as that
used in previous flotation tests except the addition of copper
sulfate to the pulp before the 5-minute agitation period for
wetting of the charge. Thus the charge was conditioned for 5
minutes with copper sulfate before the addition of the sulfldizlng
reagent. The data for this series of tests are given in table
IT.
Interpretation of results
(1) The data In table IT indicate that copper sulfate, when
added before the sulfldizlng reagent, is beneficial for improving
the grade of flotation concentrates.
(2) The extraction in test 40 was 92.5 per cent of the total
copper with a concentrate containing 7.62 per cent of copper. A
higher grade concentrate containing 11.14 per cent of copper was
made in test 38, but a lower extraction
-
Table IT - Results of Tests Employing Copper Sulfate
- $58 z
' t39 z■ ' i40 :4#:4 # (
its.! NagS ;(NH4)2S04
0.350.500.8*0.350.35
5tSI$$:iii:
0.500.75Oefi0.500.50
CUS04
*
#.800.20 0.80 0.100.15 #
z
7.17.2 6.8 7.1...
Weight of sPer cent
trate4.184.57
3.806.86
.:--(21 :95.8595.4393.9496.2093.14
88
- 8Z8:l:i:•:
" T n 6Jsate,11.148.727.62
10,247.34
tioa.
86.5 76*592.5 71.0
I18:i
comprised Amyl xanthate, 0.20; Tarol No. 1,(1) Other reagents
used in all tests 0.05; arid Q m No. 5, 0.10
(2) By difference(3) A clean unaltered pegmtlte was
1 ’V
•» •» •• »• •• •• .. .. w
-
amounting to 86.5 per cent of the total copper was obtained.(3)
In test 42 an extraction of 93.5 per cent of the
total copper as a concentrate containing 7.34 per cent of copper
was obtained when a clean unaltered pegmatite was substituted for
the gangue of the synthetic mixture.
(4) As shown in table IT, between 0.10 and 0.50 pound of copper
sulfate per ton of solids was used to obtain the improved results
described.
(5) The froths produced in these tests had much better physical
properties than those of previous tests. The chrysooolla tended to
concentrate in the froth instead of the froth-pulp interface, and
the concentrates were produced In all tests except test 39 by
allowing the froths to overflow the lip of the cell.
Denver Equipment Company Reagent "CP. Flotation Oil"
The extraction and grade of concentrate produced when a
synthetic mixture was conditioned with copper sulfate before the
addition of a sulfidizing reagent for the filming of the
chrysooolla was satisfactory when the pegmatite used for the gangue
portion of the mixture contained a minimum of oxidized material.
However when pegmatite, numbered 8, which was more altered than the
one formerly used was substituted, the resulting concentrate
produced was low grade while the extraction did not compare to the
results
-
formerly obtained-It was believed desirable to
leot ohrysooolla, and "CP notation Oil" wa dition of this oil to
the series of fate resulted in part of in the froth upon each
Preliminary tests showed that this not float chrysocolla. that a
higher extraction could of a sulfidizing reagent when using various
combinations with xanthate. numbered 43 to 54 inclusive, was able
value of "OP" Flotation Oil tlon of chrysocolla and the results
arepage 84,
X
Referring to table V# the conclusions based on the experimental
results given are as follows:
(1) "CP" Flotation Oil is a satisfactory reagent for the
flotation of chrysocolla when used in conjunction with another
promoter, and without sulphidizing.
-
Table V - Denver Equipment Company Reagent *0P" notation Oil
: pH, : Weight of :3^r eeaiiper cent *.:tail- ipxoduota.
grama:oopp#r :extra#- : : Ing :Coneen-:tailing:in . eon- : Sion
s
: (8) :eentrate; :: : ' :_________ :
: TCharge: iTest: (See Reagents used, pounds per ten of
aolidsBo.! foot-:amyl :ethyl :**CP", : QNS :
:notes) :xan- :xan- : oil :No. 5 :R-425zv/ater ztrates
___j______zthateithate:______: :_____z :43 : y(l) : 0.40 - *1.00 .—
•7.5 6.68 ! 94.32* 9.60 95.5 z_z
j:j"smt:li-f- -
: 0.40; — *o.8o * j -— -*7.4 !; 6.74 : 93.26* 7.84 #5.7* — — j
0.50jO.50 j — I •: — — j 7 • 4 j 8.49 .* 91.51 j 6.24 : 93.4
m(3) l --- * 0.50:0.50 j 0.05j — — j7.1 4.74 — — —z 95.26:
7.16
-J-76.0
x(2) ! --- : 0.50*0.50 • -— j — — :7.it : ' -
6.09 : 93.91: 8.14 US—— — i 0.50*0.50 iz
z
« ; X ; — 0.50;0.60^--- ;^~~I8el(4);
mmmmmmmmmmmrnmmmammmmmm
3.18---
96.82: 3.28
Isn,,1 ^ 0 - 2 9 : ^ 1 4 , *.87.9 z0.50:1.00 tz 0.06; 6.8(6);
5.05 ; 94.95: 9.31 ■fz :
#A*— : 0.50:1.20 : 0.05 :7.o (7); 5.78 ; 94.22: 7.01 I 80.01
Q-8ol?-3 ;
0.30:7.5(7);.~'“rir "7..
5.8S ; 94-te;93.18; 7.88
-
(2) Satisfactory results were obtained when this reagent was
used with amyl zanthate, ethyl xanthate, or
-25-
Oy&nesiid Company as a promoter for oxidized copper
mi:als.
(3) The results of test 48 indicate that tap water- Wwhoa used
without lowering the pH is detrimental to the flotation, of
ohrysocolla. , . . r/ ,
(4) The results of tests 51 to 54 inclusive showthat tap water
may be used if the pH value is first lowered*.
(5) Another crude pine, oil used in test 49 also proved to be a
satisfactory reagent for the flotation of chryso- colla. .'.r .
(6) Satisfactory extractions were obtained on a synthetic
mixture when pegmatites numbered 2 and 3 were usedfor the gangue.
An extraction of 76.0 per cent of the total copper was obtained in
test 46 when Miami sand wasused for the Qhue«. ,
-
CHAPTER 7 > ABSTRACTION Of X A H m i E■ - ■ ' ' • ’ •'
The deleterious effect of primary slime upon the recovery of
chrysooolla in the series of tests where the pulp was conditioned
with copper sulfate prior to sulfi- dlzlng led to experimental
v/ork with "CP" Flotation Oil as m promoter for chrysooolla. The
results of further experimental work given in table V chapter IT
indicated that
the chrysooolla contained in a sample of deslimed ore secured
from the Miami Copper Company as well as that in a synthetic charge
without preliminary sulfidizing. However, the use of "CP" Flotation
Oil as a promoter in conjunction with xanthate for ohrysocolla when
the primary slimes were not removed did not yield satisfactory
results as the consumption of reagents was excessive. Therefore it
was decided to do experimental work on the distribution and
comparative abstractions of xanthate by the various constituents of
the pulps used. ;
The first objective in the experimental work on the abstraction
of xanthate was to develop a satisfactory procedure. Y/ark and
Cox*13* state:
(13) Wark, I. W., and Cox, A. B., The Adsorption of Xanthate by
Activated Carbon and Graphite and Its Relation to the Theory of
Flotation, Journal Physical Chemistry, 41:673-7, May, 1937.
-
- 27-
Xanthatea, being readily prepared and purified, easily
estimated, soluble in water, and strongly adsorbed, are eminently
suitable for the study of flotation and adsorption.The oxidation of
zanthate, contained in solutions of
comparable concentrations of those used for the experimental
work, as determined by a preliminary test was found to be
negligible. A confirmatory larger scale test for the oxidation of
xanthate made in a Wallace Agitator confirmed this result.
The procedure outlined in chapter II was used for the
preliminary tests, but the results obtained indicated that this
procedure did not permit sufficient time for the system to come to
equilibrium. In all the later tests, therefore, the procedure was
modified to the extent of allowing a 2-hour period for agitation.
This time period seemed to be sufficient as the results obtained
when this period of agitation was used were not erratic, but gave
smooth curves when adsorption isotherms were plotted.
In the first series of tests, the results of which are shown
graphically in Figure 1, Nuohar, a highly activated vegetable
carbon, was used. It is manufactured by the Nuchar Corporation, a
division of the West Virginia Pulp and Paper Company, and was in an
extremely fine state of subdivision. In a preliminary test with
this material, it was found that more standard iodine solution was
required by the filtrate from the test than would be required
for
-
the total amount of xanthate originally added. Blank teats using
Nuehar and water were therefore made. The pulp was agitated for 2
hours, filtered, and 100 c.c. of the filtrate titrated with
standard iodine solution as in the regular procedure. The results
of these tests indicated that a definite amount of iodine was
required to titrate the filtrate from a Nuohar-water pulp. The
amount of iodine required for 100 c.c. of the filtrate, when 1 gram
of Nuehar was agitated with 150 c.c. of water, was equivalent to
the amount needed for 2.7 mg. of xanthate. This consumption of
iodine by the filtrate was believed to be caused by some substance
added to improve the absorptive power of the carbon and
necessitated a correction in determining the residual xanthate in
filtrates when using Nuehar. The experimental results of tests 55
to 60 inclusive are given in table VI, and the graph for the
adsorption of xanthate by 1 gram of Nuehar is given in Figure
1.
-
table VI, the following(1) The results of the series
elusive indicate that Nuohar is a very adsorbent material, as
can readily be seen by the curve shown in Hgure 1.
(8) In test 55, when 6 mg. of xanthate, an amount equivalent to
0.085 pound per ton of solution, were agitated with 150 o.o. of
water and 1 gram of Nuohar, 85.9 per cent of the xanthate was
adsorbed.
(3) When 15 mg. of xanthate, an amount equivalent to 0.20 pound
per ton of solution, was agitated with the sameamounts of water and
Ifuohar in test 56, 90,0 per cent of the xanthate was adsorbed by
the Nuohar.
-
Concentration of xnhthate In the liqu
id,
phaee ats end of test In
per
100
c.c
F i g u r e 1 - A d s o r p t i o n of Xanthete by 1 gram of
Nuchar
-29a-
-
used
» av/ator pulp was titrated.
series of tests 61 to 66 inclusive, the results of which are
given in table T O while the graphical representation of the
results is given in Figure 2.
Table T O
added.: Xanthate:in 150 o.o. $ filtrate
:$:
Xanthate 2 adsorbed, 2
.^ r o e n t " .2
— ;
-
tea
-902-
-
(1) The Pine Charcoal used in the series of tests 61 to 66
inclusive was not as highly activated as the NUchar used for the
previous tests.
(2) 72.6 per cent of the xanthate was adsorbed in test 61 when
an amount of xanthate equivalent to 0.085 pound per ton of solution
was used.
(5) When 15 mg. of xanthate was used, which amounted to 0.20
pound xanthate per ton of solution, 44.5 per cent was adsorbed.
(4) The curve of the adsorption isotherm in Figure 8 also
indicates that this charcoal is not as powerful an adsorbent for
xanthate as Nuohar.
The results of preliminary tests using slightly oxidized and
non-oxidized gangue minerals, the latter numbered 8 and 3 as
described in chapter II, indicated that xanthate was abstracted by
both types. Tests were therefore made, using these two pegmatites
and minerals similar to those contained in the gangue, to determine
the relative abstractions of xanthate by the respective minerals.
Other preliminary tests Indicated that the consumption of xanthate
by the pegmatites varied for sanples of various sized materials.
Therefore, a sample of gangue was ground to minus 48-mesh end cut
to make several samples. These were further ground
-
to minus 100 , 200, and 350 mesh respectively. The abstractions
of ranthate by the different sizes were almost identical. This
possibly indicated that in the first test a segregation of minerals
had been caused by grinding and sizing.
The results of the experimental work with various minerals are
given in tables VIII to H inclusive, and Figures 3 to 6
inclusive.
-32-
Table VIII - Adsorption of Xantbate by 50 grams of Gengue No.
2
:Test: ; No* i
Xantbate added,mss.
: xantbate :in 150 c.c. : filtrate
:::
Xantbateadsorbed,mgs.
:: - :
xantbateadsorbed
:22
: 67 ! 6 Ii 4.78:: 79.7
:2
; 68 ; 15 i: 8.19:J 6.81
:: 44.4
2$
1 6 9 ; 21Ii 13.55
!: 7.45
:: 35.5
22
i ™ ; 30i: 22.50
:i 7.50
22 24.9
t2
; 7 1 ; 45 :i 37.48 :t 7 e 52 :: 16.7 ::
-
-33-
Table IX - Adsorption of Xanthate by 10 grams of Oangue No.
9..-....r-.' ' : .-.^__ —
ft.,'.3-: . ■‘Test* Xanthate : xanthate : Xanthate 1 Per cent :i
Ho.: added, tin 150 o.o. t adsorbed. f xanthate tZ 2 «KS. t
filtrate t mgs. t adsorbed t: 72 ; 2 2 S t 2 48 : 0.52 ; 17.3
t
73 { 6 1 5.10 * 0.90 : i5.o ti7 4 ; 15 i 13.72 : i.za 5 8-5
t:
: 75 ! 21 j 19.50 ; i.so ! 7.1 :t: 76 : 30 : 28.60 : i.4o ! 4.7
:t: 77 : 2 2 45 * 43.50 ; i.so : s . 2
:t
Table X - Adsorption of Xanthate by 10 grams of quartz
ZTest; Xanthate t Xanthate t Xanthate : Per cent tadded. tin 150
o.o. : adsorbed, t xanthate $: lto*: mgs. t filtrate : mgs. t
adsorbed ' $! 78 : 3 ; i . s o : 1.50 : 5 o . o tt:: 79 : 6 ; 4 . 3
i : i . s o i 28.2 ::! 8 0 ; 15 ; 1 2 . 7 5 • ,2.25 ; i4.9 • : t: s
i : 21 ! 18.45 ; « . » : i 2 . i
%t
: e s : 30 { 26.85 : 3 . 1 5 : 10.5 :t\ •
.' i- /'I
Table XI - Adsorption of Xanthate by 5 grams of Kaolin
Test Xanthate Ho.: added,___ : mas.83 ::
: Xanthate ::ln 150 o.e. t : filtrate :i: 5.70 i:
Xanthate : Per sent adsorbed, t —ass.----l
5.0
i:w ijt:
— • !86
:-L::;
14.6020.5029.40
:JL::
0.500.60
::::
2.42.0
-
Figure 3 - Adsorption of Xenthate by 1 gram of Gangue No. 2
Figure 4 - Adsorption of Xanthate by 1 gram of Gangue No. 3
-33a-
-
Figure 5 - Adsorption of Xanthate by 1 gram of Quartz
-qss-
-
Interprets*ion of Results
From, tho results of the experimental work given in tables VIII,
H , X, and XI, the following conclusions are indicated.
(1) The ooneueption of xanthate by adsorption in teat 68 when 50
grams of Gangue No. 2 were used was 44.4 per cent. The
concentration of xanthate used was equivalent to 0.20 pound of
xanthate per ton of solution.
(2) The xanthate adsorbed in test 74, when 0.20 pound xanthate
per ton of solution was used, was 8.5 per cent. The solids used for
this test were 10 grams of Ganges No. 5.
(3) When the same concentration of xanthate was used with 10
grams of Quartz, 14.9 per cent of the xanthate wasabstracted.
(4) In test 84, 2.7 per cent of the xanthate was abstracted by 5
grams of Kaolin. The concentration of xanthate used was 0.20 pound
per ton of solution.
(5) From the graphical representation of the results obtained
for 1 gram of each substance given in Figures 3,4, 5, and 6, it is
shown that none of the materials used were as adsorbtive as the
charcoals used for the preliminary tests.
-
After the experimental m x k on absorption of xanthate by
non-copper bearing materials, tests were made using copper minerals
and a primary slime containing copper.The primary slime was
obtained by pulping a sample of ore from Miami and removing the
primary slime by decantation.W e n dried, the slime contained 2.16
per cent of copper.A preliminary test with the materials to be used
indicated that an appreciable amount of water soluble copper was
not present. The results of these tests are given in tables XII,
XIII, and XIV. The abstractions of xanthate by 1 gram of these
materials are shown in Figures ?, 8, and 9.
Table XII - Abstraction of Xanthate by 2 grams of
Chrysoeolla
jTest* Xanthate 7 Xanthate : Xanthate : Per centadded, :ln 150
o.o. t adsorbed. : xanthatee NOe * - mgs.. _ : filtrate : mgs* $; 8
7 ; 3
: '— :: 3.00 i•i 100.0
i e e i 6 ! :: 6.00 s: 100.0; 89 ; 15 : : 15.00 :: 100.0
; e° ; 18 ; i . 6 o 16.40 :: 91.2
! ci i 21 i 2.88i; 18.12
:: 86.4
! 98 i 25 : 5.30 ! 19.70 • $ : 78.8
; 93 1 27 : 6.90:: 20.10
:: 74.4
; 9* ! 30 ! 9.65 :: 20.35:: 67.7
; 9 3 ; 45 ; 24.60 :: 20.40i; 45.5
-
Table H I I - Abstraction of Xanthate by 2 grams of Chaloo-
oite
Xanthate i Xanthate : Xanthate : Per cent :T##t. added. :in 150
o.c. ! adsorbed, : xanthate 3No.. mgs.___ : filtrate : ...mgs. :
adsorbed I95 ; 3 ::
:: 3.00
:i 100.0
3S
;9 6 ; 6 :: — !: 6.00 :i 100.0 :3> i 15
%: 3.20
:! 11.80
i: 78.6 3
98 ! 21 :: 5.22:! 15.78
•■: 75.1
:t
99 : 30 !t 11.03:: 18.97
:: 63.3
3:
;x o o ; 45 ii 21.60:: 23.40 : 52.0
33
Table XIV - Abstraction of Xanthate by 2 grams of Miami
Slime
* .: Xanthate : Xanthate : Xanthate : Per cent s: added, sin 150
o.c. : adsorbed i xanthate s
ti°e: _ mgs, / : filtrate s mgs. : adsorbed ii o i ; a ; ---- ;
3.00 ; 100.0 ;i o e ; a ; ---- ; 6.oo : 100.0 :103 is ; i.65 ;
13.35 ; as.o :104 81 ; 3.16 ; 19.8*' : 85.0 {105 30 ! 4.65 : 25.35
: 84.4 *106 45 11.70 ; 33.30 * 74.0 :107: 60 1 21.00 ! 39.00 : 65.0
\
-
-a/r~
Inteipretatlon of Results• : . ; : . '' : ,, 5 ' ' • ■ ' ■ " »
'From the results of the experimental work given in
tables XII to XIV inclusive, the following conclusions are
indicated.
(1) With the concentration of xanthate equal to 0.20 pound per
ton of solution, complete abstraction by 2 grams of ohrysocolla in
test 89 was obtained;
(2) In test 97, 78.6 per cent of the xanthate was ab- straoted
by 2 grams of ohalcooite when the same concentration of xanthate
was used.
(3) In test 103, 2 grams of the Miami slime containing 2.16 per
cent of copper abstracted 89.0 per cent of the xanthate, the
concentration of xanthate remaining constant.
(4) From the graphical representation of the results• ■obtained
for 1 gram of each material given in Figures 7,
' ' - - - - - - f- ' - ' ' " ' ' ' . ' ' r " -8, and 9, it is
shown that the amount of xanthate abstracted • ' " • . • - . -by
the various materials and minerals containing copper is
greater than that abstracted by the gangue minerals.
̂-:
-
i9 2 4 6 8 ip 12lig. if xsnthste abstrncted
- |_: _i_ t o . 1 gram ©uryeficoUs.___
Figure 7 - A b s t r a c t i o n of X a n t h e t e by 1 gram of
Chrysocolla
to
: C CDH to-- Vr —
--L4 O t?
c:
Ug. of xanthate abstracted..by 1 gram Chalcqeltei-.
Figure 8 - Abstraction of X a n t h e t e by 1 gram of
Chalcocite
-
uono
entr
atiQ
n of x
aijith
ate
In t
he
pka.9
e at e
nd o
f test i
n mg.
per
Figure 9 Abstraction of Xanthate by 1 gram of Miami slimes
-
CHAPTER VI - CONCLUSIONS
From the results of the experimental work on the eul- fidlzlng
and flotation of ohrysooolla contained in synthetic mixtures and
ores described in this paper, the conclusions which follow are
indicated.
(1) The experimental work indicated that ammonium sulfate
increased the activity of the sodium sulfide as stated by Faust. As
nearly as could be determined all the sulphur contained in the
sodium sulfide was abstracted by the solids of the charge if
ammonium sulfate was used.
(2) When hydrogen sulfide was used, as nearly as could be
determined all the sulphur contained in the hydrogen sulfide was
abstracted by the solids of the charge.
(3) Satisfactory recovery of chrysocolla from a synthetic charge
was obtained in flotation after preliminary sulfidizing with
xantbate as a promoter and a pine oil frother.
(4) Vigorous agitation of the pulp during condition-ing with the
sodium sulfide did not apparently result in
• - - ~ 'abrading or oxidizing the sulfide film, and therefore
vigorous agitation is not considered harmful to the procedure.
(5) Copper sulfate, as an activating reagent for chrysocolla,
before sulfidizing, results in higher grade flotation concentrates
without loss of recovery, when the
-
- 39-
gangue used for the synthetic mixture contains a minimum of
primary slimes.
From the results of the experimental work on the flotation of
chrysooolla without preliminary sulfidizing described in this
paper, the conclusions which follow are indicated.
(6) "Gp" Flotation Oil is a satisfactory reagent for the
flotation of chrysooolla without preliminary sulfidizing when used
in conjunction with another and providing the quantity of primary
slime present is not excessive.
(7) The use of "CP" reagent resulted in the successful flotation
of chrysooolla contained in a sample of de- slimed ore from
Miami.
From the results of the experimental work on the abstraction of
xanthate by the solids of the pulp, the conclusions which follow
are indicated.
(8) Of the two charcoals used to test the procedure, Nuchar was
the more adsorbent material, though both adsorbed xanthate from the
pulp.
(9) The adsorption of xanthate by clean gangue minerals used,
compared to that adsorbed by the charcoal on the basis of 1 gram
charges as shown in Figures 2, 3, 4, 5, and 6, is small.
(10) The abstractions of xanthate by chrysooolla and chaloooite
as shown in Figures 7 and 6 are comparable to amounts adsorbed by
the pine charcoal used as shown in
-
-40-
Figure 2. The amount of zanthate abstracted by these copper
minerals is much larger than the amount adsorbed by the gangue
minerals.
(11) Though the Miami slime contained only 2.16 per cent of
copper, it abstracted more zanthate from the pulp than the fairly
pure copper minerals used.
-
BIBLIOGRAPHY
Bird, F. A............. Fundamentals in the Flotation
ofSulphidizod Oxidized Ores, E. &M. I., Vol. 125, p. 652
Fahrenwald, A. W ....... Ore toesslng Benefits by Research,E.
& M. J., Vol. 139, No. 2, Feb., 1938, p. 89
Faust, W. A.,....... .. .Sulfide Filming and Flotation
ofChrysooolla, Thesis University ofArizona, 1958, p. 29
Oaudln, A. M. ...........Flotation, MoGraw-Hill Book Co.,New
York, 1932, p. 301, pp. 507- 308
Keffer, Robert......... Methods in Non-Ferrous
MetallurgicalAnalysis, McGraw-Hill Book Co.,New York, 1928, pp.
307-308
Leininger, C. W. ........Experimental Work on the Soap Flotation
of Chrysooolla, Part II, Thesis University of Arizona, 1957, p.
5,P. 18
Rickard, T. A., and Ralston, 0. C., Flotation, McGraw-HillBook
Co., New York, 1917, p. 375
Wark, I. V/., and Cox, A. B., The Adsorption of Xanthate
byActivated Carbon and Graphite end Its Relation to the Theory of
Flotation, Journal Physical Chemistry 41:673-7, Hay, 1937
Wartaan, F. S...... ... .Associate Metallurgist, U. S. Bureauof
Mines, Southwest Experiment Station, Tucson, Arizona, Personal
communication
-
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