CA1085975A - Froth flotation process - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A process for the recovery of mineral values by froth flotation in an aqueous medium from mineral ores with the use of an effective amount of a sulfide-containing polyalkylene oxide frother.

Description

~ 85975 The present invention comprises frothing agents which improve the selective recovery of mineral values from ores and which can be satis~actorily employed in present flotation processes.
Froth flotation is a commonly employed process for concentrating minerals from ores. In a flotation process, the ore is crushed and wet ground to obtain a pulp. A
frothing agent, usually employed with a collecting agent, is added to the ore to assist in separating valuable rninerals from the undesired or gangue portions of the ore in sub-sequent flotation steps. The pulp is then aerated to produce a froth at the surface thereof and the collector assists the frothing agent in separating the rnineral values fro~
the ore by causing the mineral values to adhere to the bubbles formed during this aeration step. The adherence of the mineral values is selectively accomplished so that the portion of the ore not containing mineral values does not adhere to the bubbles. The mineral-bearing froth is collec-ted and further processed to obtain the desired minerals.
That portion of the ore which is not carried over with the froth, usually identified as "flotation tailings", is usually not further processed for eYtraction of mineral values therefrom. The froth flotation process is applicable to ores containing metallic and non-metallic mineral values.
In flo-tation processes, it is desirable to recover as much mineral values as possible from the ore while effecting the recovery in a selective manner, that i5, without carrying over undesirable portions of the ore in the froth.

18,188A-F -1- -`` 10~5975 While a large number of compounds have foam or froth producing properties, frothers widely used in commercial ~roth flotation operations include polyalkylene glycol cornpositions and alkyl ethers thereof (see, for exarnple, S U.S. Letters Patent Nos. 3,595,390, 2,611,485 and 2,695,101).
The frothers most widely used in froth flotation operations are compounds containing a non-polar, hydrophobic group and a single, polar, hydrophilic group such as a hydroxyl (O~) group. Typical of this class of frothers are, for example, mixed amyl alcohols, methylisobutyl carbinol (MIBC), hexyl and heptyl alcohols, cresols, or terpinol. Other effective frothers used commercially are the Cl-C4 alkyl ethers of polypropylene glycol, especially the methyl ether and the . .
polypropylene glycols of 140-2100 molecular weight and particularly those in the 400-1100 range.
Although mineral recovery improvements from a preferred frother in the treatment of an ore can be as low as only about 1 percent over other frothers, such apparent small improvement can be of great importance economically since a commercial operation will often handle as much as 50,000 tons of ore daily. With the high throughput rates normally encountered in commercial flotation processes, relatively small improvements in the percentage rate of mineral recovery will result in the recovery of a substantial increase in additional tonage of minerals daily. Obviously, ; any frother which promotes improved Mineral recovery, even though small on a percentage basis, is very desirable and can be advantayeous in commercial flotation operations, especially ln view of increasing energy costs.
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18,1~A-F -2-.
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~08597S

In accordance with the present invention, it has been found that, in a process for collecting mineral values frorn an ore which comprises mixing ~round ore with water to form an ore pulp, aerating said pulp in the presence of a frother agent, improved recovery results are obtained with sulfide-containing polyalkylene oxide compositions (here-inafter referred to as "frothers") of the general formula:
(R)n-S-R
(R2) wherein, in said formula R represents alkenyl of 3-5 carbon atoms, an alkyl group of from 1 to 8 carbon atoms, or an aryl group, nl represents -(EO)X(PO)y(BO)zH, R2 represents -(EO)x,(PO)y,(BO)z,H, wherein

2 4 ' po = C3H6O~ and BO = C4H8 n = 0 or 1, m = 0 or 1, with the proviso that when n = 1, rn = 0 and x = 0-4, ..
y = 1-10, z = 0-2, the sum of the x, y and z groups being an average from 2 to 12 with the further proviso that when m = 1, n = 0 and x and x' each are 0-2 y and y! each are 0-7 ;; z and z' each are 0-2 . the sum of the x + x' + y + y' + z + z' groups being an average of ~rom 4 to 14, with the proviso that at least one :"

18,188A-F -3_ .
-'^-" 1~8S975 of x, y or z and at least one of x', y' or z' is always at -least one and with the further proviso that when y and y' are each 0, at least one of z or z' are at least 1.
As used herein, the term "average sum" means the average number of EO, PO or BO groups per molecule in a given composition and also includes mixtures of composi- ;
tions having varying amounts of the same all;ylene oxide group such as, for example, a product mixture of frother compositions RS(PO)3~I, RS(PO)5H and RS(PO)7H wherein the average sum of PO groups per molecule in the product mix-ture is 5. The average sum of al~ylene oxide groups present in a given mixture can readily be determined according to conventional procedures.
The pure compositions as such are useful in the method of the present invention although the.reaction .
mixtures or mixed fractions are desirably utilized as these .
are effective and can be utilized without additional costly ~ -purification steps. The PO-reactants (C3H60) include 1,2- ~
and 1,3-propylene oxide while the BO reactants ~C4H80) are :
meant to include only 1,2- and 2,3-butylene oxide.
As used herein, the term "al~yl" means and includes straight- or branched-chain radicals such as, for.
examplej methyl, ethyl, isopropyl, butyl, t-butyl, pentyl, n-hexyl, isohexyl, heptyl, octyl, or isooctyl. The term 2~ "aryl" as used herein means, for example, phenyl, benzyl, and su~stituted phenyl radicals derived from,.for example, toluene, ethyl benzene, cumene, xylene, or t-butyl benzene.
Li~ewise, the benzyl radicals can bear various substituents which do not affect the basic frother properties of the compositions.

18,1~8A-F _~_ - . : . : ~ .

1~)85975 Mixtures of compositions of the above formula are preferred for use in the present invention. Compositions of the above formula wherein n is 1 also constitute a pre-Eèrred class herein. Compositions wherein n is 1 and R is an alkyl group constitute another preferred class. In another preferred embodiment n is 1, z is 0 and the sum of x + y is from 2 to about 8. In another embodiment, mixtures of compositions wherein n is 1, z is 0 and the average sum of x + y is from about 2 to about 8 are preferred. Mixtures of the foregoing embodiment wherein R is also an alkyl group of 1 to about 6 carbon atoms co~prise a further pre-ferred class. Mixtures of compositions wherein n is 1, z is 0, the average sum of x + y is from 2 to about 8 and R is a methyl group are also preferred. In a further embodiment, mixtures of compositions wherein n is 1, x and z are each 0, the average sum of y is from 2 to about 8 and R is an alkyl group of 1 to about 6 carbon atoms are preferred. Mixtures of compositions wherein x and z are each 0 and the average sum of y is 5 or 7, respectively, consiitute other preferred embodiments. ~lixtures of compositions wherein n is 1, x and z are each 0, the average sum of y is 5 or 7, respect-ively, and R is an alkyl group of from 1 to about 6 carbon ; atoms are particularly preferred.
Another preferred embodiment includes products of the above formula wherein m = 1. Thus, products wherein z and z' are 0 and the average sum of x + x' + y + y' is from 4 to about 14 are preferred. In another preferred embodiment, z and z' are 0 and the average sum OI X + Xl + y + y~ iS from 4 to about 10. In still another embodlment, z and z' are 0, x + x' is an average sum of 1 to about 4 and y + y' is an .:

~ 18,188~-E -5- ~
, - - : . . .

average sum of 1 to about 8. Also preferred are mixtures wherein x and x' and z and z' are all 0 and y + y' is an -average sum of from 4 to about 14. Additional preferred mixtures are those where x and x' and z and z' are all 0 and y + y' is an average sum of from 4 to about 10. Another pre-ferred class includes mixtures wherein x and x' and.z and z' are all 0 and y + y' is an average sum of from 4 to about 8.
In an additional preferred embodiment, x and x' and z and z' .:~
are all 0 and y + y' is an average sum of 7. In still another -.
embodiment, x and x' and z and z' are all 0 and y + y' is an average sum of 5. Another preferred mixture is where z and :
z' are zero, x + x' represents an average sum of 2 and y + y' .
represents an average sum of 4.
Since it is difficult and prohibitively expensive to prepare pure or substantially pure compositions, reaction product mixtures containing mixed fractions of the same or different alkylene oxide moieties are desirably utilized as they are less costly. Thus, in additional embodiments, it will also be readily apparent to those skilled in the art that the average or average sum of x + x.' + y + y' + z + z' - refers to the average content of-the all;ylene oxide moieties per molecule in a given composition. The actual amount of each fraction may be the same or different and the average sum of alkylene oxide moieties per molecule in a given mix-'! 25 ture can readily be determined. By way of illustration, a product mixture having àn average PO moiety content of about 10 per molecule may be comprised o~ about equal amounts of frother fractions having average PO moiety contents of 6, 10 and 14, rPspectively.
The frothers of the present i-nvention are added to the ore and intirmately mixed therewith either alone or 18,188A-F -6-..
: ' , ~ . ' ' together with a collector prior to and/or during the flotation step. The ore pulp-frother mixture is then treated under conditions to form a froth. The froth selectively removes the mineral values from the ore and the mineral-rich froth is separated from the ore flotation pulp and recovered. The value-depleted pulp which remains in the flotation cell is removed. The mineral-rich froth is further treated to recover the desired mineral values In accordance with the process of this invention it has been found that both the amount of mineral values which are recovered and the concentration of mineral values in the froth are substantially increased over prior processes which employ known frothers. These processing improvements are obtained with substantially the same or lower quantities of frothing agents as compared to those used currently in flotation operations. Accbrdingly, the present invention provides substantial advantages over prior processes.
The frothers of this invention can be employed in the flotation of metallic and non-metallic ores. Ores 20 - which are processed include, for example, sulfides and oxides of copper, molybdenum, lead, zinc, iron, nickel or cobalt. Such ores may also contain precious metal values such as, for example, gold, silver or platinum.
Other ores which can be processed are, for example, phosphate rock, cement rock, glass sands, feldspars, fluorsparsr micas, clays, talcs, coals or ores containing tungsten, -manganese, sulfur, or water-soluble minerals such as sodium or potassium-chlorides. Preferably, the frothers of the present invention are employed in the recovery of copper or molybdenum, most pre-Eerably molybdenum. The frothers 18 r 188A--F _7_ ' .' ' -^` 1085975 of this invention are employed in amounts of from 0.005 lbs. per ton of ore to 0.5 lb. per ton of ore; preferably from 0.01 lb. per ton of ore to 0.1 lb. per ton of OLe.
Those skilled in the art will recognize that the amount of frother will vary depending, for example, upon a given plant operation, ore type, and that the optimum amount will be determined by mill trial runs.
The frothers of the present invention are pre-pared by methods known in the art, including block polymer preparation methods.
The frothers where n is 1, i.e., mercaptan frothers, may be prepared by reacting an appropriate mercaptan of the formula RSH, wherein R is as hereinabove defined, with an alkylene oxide (e.g., ethylene-, propylene- or butylene-oxide) or mixtures thereof. The greater the quantity of the alkylene oxide used, the longer the chain length and the higher the molecular weight of the mercaptan frother obtained. The mercaptan reactants utilized to prepare the mercaptan frother agents are known in the art and can be readily obtained or prepared by known methods by those skilled in the art. Typical of such mercaptan agents are, for example, methanethiol, propenethiol, butenethiol, l-butanethiol, 2-butanethiol, thiophenol, benzyl mercaptan, toluenethiol, 4-t-butylthiophenol, 2-methyl 2-propanethiol. Also allyl alcohol can be reacted with a mercaptan RSH in the presence of ultra violet light to give RS(C~I2)30H, whlch can then be further reacted with E0, P0 or BO reactants to obtain the product desired.
The preparation of the frothers of the present invention is effected in the presence of a catalyst such as ', 18,188A-F -8-:
.

alkalies, e.g., sodium or potassium hydroxide. The re-action may be carried out sequentially with either the EO, P0 or BO reactants being added first or concurrently where two or more oxides are reacted as a mixture,. Reaction temperatures ranging from 50C to 225C may be employed and pressures ranging from ambient up to 1000 pounds or more per square inch may be used.
Frothers wherein m = 1 can, for example, be pre-pared by bubbling sufficient quantities of hydrogen sulfide gas through a solution of the polyalkylene oxide reactant, i.e., ethylene oxide, 1,2- or 1,3-propylene oxide, 1,2-or 2,3-butylene oxide, or mixtures of these reactants, de-pending upon the final product desired. The ~rothers can also be prepared by reacting a mixture rom which H2S can be generated, e.g., sodium sulfide in methanol, with an ethylene-, propylene- or butylene-chlorohydrin reactant.
Larger chain, higher molecular weight frothers can also be prepared by further reacting frothers prepared by any of the above witn additional quantities of the desired EO, PO or BO reactants and/or mixtures thereof under similar conditions as described. Additions of the EO, PO or BO
reactants, including the chlorohydrins, can be carried out se~uentially or concurrently ~ith two or more of the reactants being added as a mixture.
The n~ercaptan frothers useful in the present invention may be characterized in terns of their molecular weights. Products of average molecular weight in the range of from 150 to 1000 are suitable for use as frothers with the ranye of 200 to 700 being preferred.

18,188A-F -9-The quantities of reactants are adjusted so that a frother of desired molecular weight may be obtained. For example, a molar quantity of the mercaptan reactant is reacted with sufficient amounts of the EO, PO or BO
reactants, either separately or in combination with one or both other oxides, so that the final polymeric condensate, in either block or random forrn, is of the molecular weight range desired. The amounts of the EO, PO and BO reactants necessary to achieve the various compositions within the above-defined formula will be readily apparent to those skilled in the art, who will also recognize that the chain length is based on an average determination of EO, PO and BO groups present.
The frothers of this invention can be employed either alone or in conjunction with standard frothers as previously mentioned herein and with a conditioning agent or modifier and/or a water-soluble or oil based collector or promoter. Suitable water-soluble collectors or promoters which can be employed in the flotation of sulfide or oxide metallic ores are for example, alkali metal xanthates, sodi~m or potassium ethyl, isopropyl, secondary or isobutyl, arnyl, or isoamyl and hexyl xanthates, alkyl thiols, dithiophosphates such as dicresyl, diethyl, diisopropyl, disecondary or di-isobutyl, diamyl or diisoamyl and dihexyl dithiophosphates as free acids or as sodium, potassiurn or ammonium salts, as well as rnercaptobenzothiazole derivatives. Representative oil based collectors which can be employed with the frothers of this invention include dithiocarbarnates such as, for example, S-allyl-N-ethyldithiocarbamate, S-allyl-N-isopropyldithiocarbarnate or S-allyl-N-methyl-dithiocarba-:, ' 18,188A-F -10-, mate, as well as allyl xanthates, dialkyl thionocarbarnates or (alkoxycarbonyl)alkyl xanthates; these collectors are oil-soluble.
In the ~lotation of non-metallic ores, suitable water-soluble and oil-soluble collectors or promoters are for example, oleic acid, crude or refined tall oil, or tall oil fatty acids, naphthenic acids, the sodium, potassium, or ammonium soaps of such acids, black liquor soap, petroleum sul~onates, organic phosphates or polyphosphates, sulfonated oils or fatty acids, sulfosuccinates or sulfosuccinamates.
Cationic type collectors such as, for example, long chain ;
amines or irnidazolines are ernployed in the flotation of silica or silicates or water-soluble minerals.
. .
Depending on the type of ore treated, conditioning or modifying agents such as, for exarnple, alkalies or acids to adjust the pH level of the ore slurry to improve select-ivity may be used. Additionally, flotation depressants to inhibit the flotation o~ unwanted minerals, or activators to enhance flotability and improve flotation rates may be used with the frothers of ~his invention.
The following examples illustrate the ~rocess of the present invention and the superiority of the claimed frothers over related oxygen analogs. In these examples, EO, PO and BO are used to designate ethylene oxide, propy-lene oxide and butylene oxide, respectively.
Example 1 Powdered sodium hydroxide (0.5 grams) and methyl mercaptan (48 grams) are placed in a one liter Parr bomb reactor equipFed with a stirrer, an internal cooling coil and preheated to about 75C. An EO-PO mixture (27.6 grams;
.~ , .. ~ ' .
18,188A-F -11-,~
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prepared from 44 grams of EO and 232 grams of PO) is initially added, portionwise, to the reactor at a rate so as to maintain the temperature of the reactor below 150C.
I'he remainder of the EO-PO mixture is also subsequently added, portionwise, to the reactor and the resulting mixture is heated at 150C for a period of about one hour. The product CH3-S(EO)X(PO)yH, x being 1 and y being an average of 4, is recovered in typical procedures.
Example 2 111.2 Grams of a previously prepared product CH3S(PO)yH, wherein y is an average of 3 and about 5 grams of powdered KOH were reacted with 36 grams of BO. The BO
was added portionwise and the exothermic reaction was main-tained at a temperature of 150-160C. Following the com-pletion of the BO addition, the reaction mixture was heated to 150C for an additional one-half hour and then filtered hot through Celite. The resulting product was CH3S(PO)y~
(BO)zH wherein the average sum of y was 3 and z was 1.
Example 3 Ground, hydrated sodium sulfide was dissolved in 300 ml of methanol and a small portion of propylene chloro-hydrin was added thereto. No exotherm Irom the reaction ' temperature of 18C was observed. The reaction temperature was increased to about 50C and additional propylene chloro-hydrin was added portionwise until a total of 189 grams had been added. The solvent was then stripped from the reaction mixture on a vacu,um rotary evaporator, the residue was taken up in ether and the resulting mixture was washed with water and dried over MgSO4. The ether and MgSO4 were sub-sequently removed and the oily residue obtained was distilled.
As a result of these operations there was obtained the 18,188A-F -12-., .

-` 1085975 desired product: H(PO)y,S(PO)yH having a boiliny point of 110-112C at 1.5 mm of Hg, y' + y being an average total sum of about 2.
E.xample 4 About 7.95 grams of a previously prepared E0 frother: H~EO)S~EO)H was reached with about 18.2 ml of propylene oxide and 0.1 grarns of powdered KOH. The resulting reaction mixture was heated at about 150C for about 2 hours in a closed Carius tube. As a result of ~-such operations the liquid product: H(PO)y,(EO)S(EO)(PQ)yH
wherein the two EO groups are attached to the sulfur atom and wherein the total average surn of y + y' is about 4, was obtained. -Example 5 , . .
~ reaction mixtUre of powdered KOH (0.5 gram) and 2-mercaptoethanol is preheated to about 75C in a Parr bomb equipped wLth a stirrer and an internal cooling coil and an initial 18 g. of a mixture of ethylene oxide (29 g.)-propylene oxide (77 g.) is added portionwise thereto at a rate so that the reaction temperature does not exceed 150C.
The remainder of the mixture is subsequently added in por-tions and the res~lting reaction mixture is heated at 150C
for about 1 hour. The resulting product is H(PO)y,(EO)x,~
S(EO)X(PO)yH wherein the total average sum of x + x' is 2 and y ~ y' is 4. This product is distinguished from the product obtained in Example 6 above in that the E0 groups q are not all directly attached to the sulfur atom. This ex-ample illustrates the random preparatlon of the frother ' polymers.
The foregoing examples illustrate typical proce-dures by which frothers employed in the invention can be ., .

1&,188A-F -13-" ;. . ~ . ., . ~ .
., . . . , ~: . , , : . .

~ 1085975 prepared. Other frothers within the scope of the invention can be similarly prepared by the foregoing or other anala-c~ous methods known by those skilled in the art.
The following procedure and examples urther illustrate the method of the present invention.
In typical frother evaluation methods ~nown to those skilled in the art, a 500 gram sample of ore is crushed to -10 U.S. Mesh and then further ground in a rod mill with 300 milliliters of distilled water until sub-stantially all of the sample passes through a 65 U.S. Mesh screen. An initial amount of a collector is added to ~le ~-resulting ground slurry along with a kerosene-fuel oil mixture and lime, the final adjusted pH for flotation being about 10.2.
The slurry from the rod mill was washed into a Denver-type flotation cell. The cell is operated at about 1800 rpm, with an auto~atic paddle operating at about 10 rpm, ~ith air being metered into the cell at a rate of about 7.0 scfm (standard cubic feet per minute). Fro~her is added to the slurry which is then conditioned for 2 minutes without air being metered into the cell. The air is turned on and a first flotation concentrate is subsequently obtained as a result of 2 minutes flotation time. The air is then turned off and this first concentrate is removed. Additional collector is added to the slurry along with additional frother and the slurry is conditioned for one minute without air and then floated for two minutes. This conditioning and floating procedure is repeated (without r~-noving the concentrate for-med), giving a second (scaven~er) concentrate which has been floated for a period of 4 minutes. The concentrate and remaining tail are then analyzed; where two con~entrates ~ '' .
18,188A-F -14-~ ~085975 are obtained from the same trial, the results are totaled.
Results obtained from separate trials with a test material are averaged. `
Example 6 ' S Results, including the type of frother agent used, total amounts of frother agent used per ton of an Arizona ;
ore and percent recomery of copper (Cu) and molybdenum (Mo) obtained from trials according to the above procedures, are set forth below in Table I. A dialkylthionocarbamate (0.012 lbs/ton) was used as a primary collector while sodium li isopropyl xanthate (0.005 lbs./ton) ~Jas used as a secondary ' -collector. Mixed frother compositions were used.
. . . 1 ' ., 18,188A-F -15- ~

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h ~ N D CO~1 ~ ~ ~ ~1 Ot~l ~r c~ ~ocl 1--r`,--1 ~
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C) R
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H O
U~
. ~m~ ~, ~, q, CO 0~ 0 0 ~ ~ o o E~~ o ~ ~ ~o~
' ~D O ~ a~
~1 O O O O O O ' ~ Id Id ~r ~ u~ -: -o A ~ '1--) ~I l'd ~d O O O
al td O R R R
N X X ~ ~ ~
~ ~ ' O O O
.` :C ^ ^ Q) ~ O
" ~ O ~ ~ ~ ~ ~ O C~
O P~ o ~,~ O O
N ~ m ~ 3 ~_ ~ ~ o ~ ~ ~ ~ ~ ~ +
s~ ~tn oo ~ ~ ~ ~
~J ~~ m1~ -- O O O ~ ~ h 11 S~ 11 11 11 ~ ~ X P.P~ p~ O O ~ 1 aJ a :~ O ^O ^ ^ O U~ O ~
s~ o u~ o o ~ $o ~ + + +
~ ~ O U~ U~ ~ O O O C~ E~ ~ U~ ~ ~ ~ ~ ~ ~
m ~ ~ ~ ~ ~
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!~ ' 18 ,188A-F --16--` 108S975 The foregoing data illustrate the effectiveness of various mercaptan frothers used in the invention and the superiority of the same over a co~nrnercial standard frother, MIBC, even at substantially lower use rates.
While increases of a single percent in recovery rates are significant, the mercaptan frothers tested above provide very significant and unexpected increases of from about l~ to as high as about 5%.
Example 7 In operations utilizing the procedures of Example 6 above, certain frother mixtures of the invention were compared with related oxygen analogs. In all tests, isopropyl ethylthionocarbamate was used as a collector in an amount of 0.032 lbs./ton, the pH level was about 10~75 and the ore was a Peruvian copper ore., The results are set forth below in Table II.
Table II
, Run ~6 Cu % Cu% Cu No. Frother lbs/ton Head TailRecovery (1) DP~S 0.252 0.830 0.253 70.87 20 (2) DPkSS 0.238 0.831 0.l78 79.74

(3) TP~1 0.136 0.787 0.240 70.65

(4) TP~lS 0.140 0.802 0.226 73.03 -DPl~S = CH30(PO)2H
DP~SS = CII3S(PO)2H
TP~I = C1130(PO)3~ -TP~S = CH3S(PO)3H
The mercaptan frothers having an averaye of 2 PO or 3 PO units were clearly superior in frothing power over the corresponding oxygen analogs.
i l8,l88A-F -17-, Example 8 -In other evaluations employing similar procedures, as in Example 6, the following results were obtained on a Peruvian copper ore:
TABLE
Run Recovery No. _ Frother lbs./ton % Cu % Mo 1 MIBC 0.13965.09 56.01 2 CH30(EO)l(P0)4H 0.084 70.45 61.52 CH3S(EO)l(P0)4H 0.090 `70.78 63.05 The above data indicate the superior frothing properties of the mercaptan frother, especially in Mo recovery, over a commercial standard frother, MIBC, even at lower concentration, and over a related oxygen analag. . .
Example 9 In further trials employing the general procedures of Examples 6 and Peruvian copper ore samples the following results were obtained:

18,188A-F -18-1085975 ;:
TABLE IV . ~.
Run Conc. Assay ~ y ~::
No. *Frother ~ % Cu % Mo ~ Cu % Mo (1) (a)MIBC 0.290 12.4 0.278 76.70 61.83 : .
(2) ( )CI~30(PO)yH~ 0.234 14.3 0.334 76.48 68~22 ~ :
(3) (C)CH3S(PO)yH0.188 16.4 0.416 78.55 74.76 ~
(4) " 0.226 15.9 0.384 77.19 77.28 ~ :

(5) " 0.263 14.4 0.349 78.13 78.07 .
* isopropyl ethylthiono carbamate -~
(O.03 lbs/ton) was used as a collector.
(a) methylisobutyl carbinol, ~ Cu recovery is .
average of two separate trials. :~
(b) y = average of 3.6, % Cu recovery is average .
of three runs, % Mo recovery is average of .:
two.separate trials. . . .:
(c) y = average of 3.75; ~ Cu recovery.for Runs 3-5 is average of three trials, % Mo recovery i9 average of two trials for Run,s 3-4 and three trials for Run 5.
The results of the above tests demonstrate the .
superior frothing properties of the mercaptan frothers as .-compared to commercial frothers (Runs 1-2), including an oxygen analog product (Run 2). In recovery of Cu, it :, . . .......................... . .
is noted in Run 2 that use of the oxygen analog resulted ~
in less Cu recovery compared to the standard frother (MIBC), whereas the frothers of the present invention resulted in from about 1.0 to 2.0% increases in Cu-recovery as compared with MIBC. Similarly, the frothers of Runs 3-5 exhibited .-far superior and unexpected frother properties in the .
recovery of Mo as compared with both MIBC and the oxygen analog of Run 2, Mo recovery being from 20-25 percent better than with MIBC, and from about 8 to 15 percent better than with the oxygen analog.

18,188A-F -19-1~8S97S ~:

Example 10 In operations utilizing the procedures set fortl~
above, a mixed frother agent was compared with the oxygen analog and the commercial MIBC product on a South American copper ore. The pH was 10.4 and a collector (isopropyl ethylthionocarbamate, 0.032 lbs./ton) was employed in the evaluations, the results of which are set forth below and -reflect the average recovery values from two duplicate trials:
TABLE V
Run Recovery No. Frother - lbs./ton % Cu % Mo 1 A 0.090 69.37 57.12 2 B 0.085 65.27 55.68 3 MIBC 0.093 56.31* 51.76 4 A 0.112 71.79 61.35 B 0.106 69.17 58.10

6 MIBC 0.116 65.62 60.18

7 A 0.157 74.55 64.77

8 B 0.148 73.30 63.26 A = H(PO)y~(E0)x~S(E0)x(PO)yH~ average sum of x + x' is about 2 and average sum of y + y' is about 4.
B = H(PO)yl(E0)x~O(E0)x(PO)yH~ average sum of x + x' is about 2 and average sum of y + yl is about 4.
C = MIBC - methylisobutylcarbinol.
* = single trial only 18,188A-F -20-,:
As compared with ~he oxygen analog B, frother (A) possessed superior frother properties in all trials, increases in Cu and Mo recovery of from at least 1% to as high as 4% for Cu and from 1-1/2~ to 3~ for Mo. As compared with a commercially used frother, MIBC, the rother ~ was far superior, increases from 6-13% in Cu -.
recovery and 1-5% in Mo recovery being obtained. :
Exarnple 11 The procedures set forth above were repeated using a typical pH and collector and copper ores from two different sources (Ore #1 - Runs 1-5, Ore #2, Runs 6-8).
An oxygen analog of a mixed frother and a commercial ~.
frother are also employed for comparative purposes. The . - :
results are set forth below in Table VI:

- .

.

18,188A-F -21-.- . . . .. ~ : . ~ .

I~ o ~ o U n ~ , ~ ~ ~ ~ ~ U~ o~ o s~
o ~1 ~r ~ o cn ~D ~1 0 d~

o ~ ~ ~ I~
O ~ ~ ~ o ~ In ~ o .
,~ o ~ ~1 ~1 ,1 ~,1 ~D ~ ~r ui :~ Q O O O O
Q
~! q~
E~ O O O O
0 - ~
m~ m~ a) a) a~
ô ô
' X X
ô o r~
S~
m m u~ m u~
^ ~ ^ X ^ X
S~~4 ~ ~ ô ~ ~ ~ X ~D R
U~ O U~
. . ~ ~ ~ ~ ~ ~ ~ ~ ~ X
O O O O O O O
-- -- -- -- H`-- -- H ~ ~D 1`
m m ::c m :~: m m ~

a) ~ a~ a) a) Cl ~ ~ H

' 18 ,188A--F

..

~" 1085975 In other operations, other frothers as defined herein and ~ixtures thereof are found to possess similar superior frother properties.

. .
'' "'' "'' '' ' ~ 18,188A-F -23-

Claims (10)

1. A process for collecting mineral values from an ore which comprises mixing ground ore with water to form an ore pulp and aerating said pulp in the presence of an effective amount of a frother, characterized by carrying out said process with a frother of the formula:

wherein, in said formula R represents alkenyl of 3-5 carbon atoms, an alkyl group of from 1 to 8 carbon atoms, or an aryl group, R1 represents -(EO)X(PO)y(BO)zH, R2 represents -(EO)x,(PO)y,(BO)z,H, wherein EO = C2H4O, PO = C3H6O, and BO = C4H8O
n = 0 or 1, m = 0 or 1, with the proviso that when n = 1, m = 0 and x = 0-4, y = 1-10, z = 0-2, the sum of the x, y and z groups being an average from 2 to 12 with the further proviso that when m - 1, n = 0 and x and x' each are 0-2 y and y' each are 0-7 z and z' each are 0-2 the sum of the x + x' + y + y' + z + z' groups being an average of from 4 to 14, with the proviso that at least one' of x, y or z and at least one of x', y' or z' is always at least one and with the further proviso that when y and y' are each 0, at least one of z or z' are at least 1.

2. The process of Claim 1, characterized in that the frother is employed with a mineral collector.

3. The process of Claim 1 or 2, characterized in that mixtures are employed.

4. The process of Claim 1, wherein when z is 0 the average sum of x + y groups is from about 2 to about 8.

5. The process of Claim 1, wherein when x and z are 0, the average sum of y is from about 2 to about 8 and R
is an alkyl group of from 1 to about 6 carbon atoms.

6. The process of Claim 1, wherein z and z' are 0.

7. The process of Claim 6, wherein the average sum of x + x' + y + y' is from 4 to about 10.

8. The process of Claim 6, wherein x + x' is an average sum of from 1 to about 4 and y + y' is an average sum of from 1 to about 8.

9. The process of Claim 6, wherein x and x' are 0 and y + y' represents an average sum of from 4 to about 14.

10. The process of Claim 6, wherein x + x' represents an average sum of 2 and y + y' represents an average sum of 4.