Experimental work on the flotation of chrysocolla

Item Type text; Thesis-Reproduction (electronic)

Authors Rutledge, Franklin Allen

Publisher The University of Arizona.

Rights Copyright © is held by the author. Digital access to this materialis made possible by the University Libraries, University of Arizona.Further transmission, reproduction or presentation (such aspublic display or performance) of protected items is prohibitedexcept with permission of the author.

Download date 15/06/2021 06:52:24

Link to Item http://hdl.handle.net/10150/553452

http://hdl.handle.net/10150/553452

EXPERIlffiMTAL WORK ON THE FLOTATION OF CHRYSOGOLLA

t»y

submitted to the faculty of the

the requirements for the 1

1959

- 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.

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

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

. 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* ■ •

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.

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.

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-

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

19 5 3

E ^ l . 1=131 -51

L a 39 00 1 0 0 12 8 2766b

NUJ.VILLniAI tiO S S O l dOd aaodVHO 3- miM 00'1$ JO 3 3 d V LL3X30d

> O C 3 l^lOtid Qt iVD SIH± 3AOIAI3H ±O N OQ

£ ? ? ? /

'/I9 3 JS ?

2—