US3341135A - Flotation method for potash ores - Google Patents

Description

United States Patent ()fiice 3,341,135 Patented Sept. 12, 1967 3,341,135 FLOTATION METHOD FOR POTASH ORES Martin Wilson, Anaheim, Calif, assignor to United States Borax & Chemical Corporation, Los Angeles, Calif., a corporation of Nevada No Drawing. Filed Sept. 16, 1964, Ser. No. 397,036 10 Claims. (Cl. 24120) This invention relates to methods for obtaining desired mineral values from ore by froth flotation using a novel flotation reagent combination, and especially for obtaining potash from potash ore.

In the reccovery of desired mineral values, such as potash, from ores, the ores can be comminuted to a small size and submitted to froth flotation procedures to separate the mineral from the other constituents of the ore. The long chain aliphatic amines are well known as collector reagents in such froth flotation procedures. However, it has been found that potash of larger than 14 mesh particle size cannot be efliciently floated with higher alkylamines alone. Accordingly, it has been purposed that certain auxiliary reagents can be employed in combination with the amines in order to promote flotation of the large size particles. For example, my US. Patent 3,059,774 issued Oct. 23, 1962, discloses and claims the use of certain alkylnaphthalenes, the chloro and hydrogenated derivatives thereof, alkylmercaptans and dialkylsulfides, and their aryl derivatives, dialkyl sulfides and dialky polysulfides as auxiliary reagents. Also, my copending US. patent application Ser. No. 169,963, filed Jan. 30, 1962, now Patent No. 3,149,788, discloses and claims the use of indane and alkylindans as auxiliary reagents. These combinations provide an excellent grade (purity) of product, but the recovery is not as high as desired.

The present invention provides a novel flotation reagent combination which gives an excellent grade of product and also a very high recovery of product. The superior reagent combination of this invention comprises an admixture of a long chain aliphatic amine collector reagent and a polycyclic aromatic auxiliary reagent having at least three rings in the molecule. The oreis treated in the usual manner associated with froth flotation techniques, well known to those skilled in the art.

Thus, there is provided by the prevent invention the method of obtaining desired mineral values from ores by froth flotation which comprises comminuting said ore, pulping the comminuted ore, treating the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and a polycyclic aromatic auxiliary reagent having at least three rings in the molecule, subjecting said treated or pulp to a froth flotation cell, and recovering said mineral values from said flotation cell.

The polycyclic aromatic auxiliary reagents useful in this invention have at least three rings in the molecule. They are high-boiling hydrocarbons, consisting mostly of the I higher alkyl derivatives of condensed ring systems, which are obtainable as residues from the cracking of mineral oils. Many are known as reformate ends, cycle oils or products from cycle oils. They are generally characterized by a distillation range within about 500 to about 800 F., low pour points, such as below about 20 C., and relatively low viscosities, such as SSU of less than about 100 at 100 F. Usually such polycyclic aromatic oils occur as mixtures of condensed ring systems having 3 to about 5 rings and are predominantly tricyclic and tetracyclic hydrocarbon compounds, such as the acenaphthenes, fluorenes, phenanthrenes, pyrenes and benzonaphthenes. Such mixtures can also contain minor amounts of other lower ring systems such as alkylindans, Tetralins, and naphthalenes.

The amine collector reagents employed in the present invention are those used by ore refiners in conventional flotation processes. The collector reagents are long chain aliphatic amines, saturated and unsaturated, having from about 7 to about 18 or more carbon atmos and are most commonly prepared from beef tallow. They are usually used as the salts of the amines, the most commonly used salt being the acetate, and they can be purchased commercially as mixed aliphatic amine acetates. The weight ratio of amine to polycyclic aromatic reagent is preferably about 1: 1, although greater or lesser amounts can be employed and are desirable for some ores.

The ore is treated, following normal procedures, prior to being subjected to flotation with the regeant combinations of the present invention. Thus, the ore is comminuted, such as by grinding to a suitable particle size of about 8 mesh. The comminuted ore is then pulped by slurring'it in a saturated brine composed of the soluble constituents of the ore. If the ore contains clay contaminants, it is preferred to deslime using conventional procedures, such as by screening the slurry through, for example, a -mesh screen to remove the clay and fines. The ore pulp is then treated with the flotation reagent combination and the treated ore subjected to a conventional froth flotation cell. Preferably, the deslimed feed is split prior to flotation into coarse and fines and the two fractions treated separately with the flotation reagents to avoid excessive consumption of the reagent. After treatment (reagentizing), they are recombined for flotation.

In a preferred embodiment of this invention, I employ as an auxiliary reagent, a combination of the abovedescribed polycyclic aromatic reagents and at least one additional material selected from the group consisting of indane, the alkylindans in which said alkyl substituents have from one to about eight carbon atoms, alkylnaphthalenes and the hydrogenated derivatives thereof, in which said alkyl substituents have from one to about eight carbon atoms. By employing said combination, an excellent recovery of very high grade ore is readily obtained. The combinations also retain the advantages of low pour point, low viscosities (preferably less than about 70 SSU at 100 F.) as well as relatively high volatility which results in oil-free ore concentrates after any drying procedure. A further advantage of the blends is the flexibility which can be obtained by varying the proportions of the components in order to adjust the auxiliary reagent to the possible changing characteristics of the ore (degree of liberation). However, a ratio of polycyclic aromatic to alkylindan or alkylnaphthalene of about 1:1 is normally employed.

The indanes, alkylindans, alkylnaphthalenese, and their derivatives are described in my US. Patent 3,059,774 and my copending application Ser. No. 169,963, referred to above. They can be employed as the pure compounds, as mixtures of such compounds or as mixtures with related compounds. Whenever such mixtures are employed, the indanes, alkylindans, alkylnaphthalenes, and their derivatives should be present in such amount as would provide the equivalent of the reagent as would be required in the flotation process if they were to be used in a substantially pure state.

The following examples are presented to illustrate the present improved process, but the invention is not to be considered to be limited to the specific examples given.

Example I Sylvinite ore was ground to a -8 mesh size and was slurried in a saturated brine composed of the soluble constitutents of the ore. The slurry was then deslimed through a 100-mesh screen to remove the fines and insoluble matter, and the deslimed ore was wet-screened and divided into two fractions, one fraction containing the +20 mesh particles and the other fraction containing the -20 mesh particles. The +20 mesh fraction was conditioned with 0.32 pound/ ton of a 50-50 mixture of amine colector reagents (50% of a mixture predominantly hexadecyl and octadecyl amines and 50% of a mixture predominantly hexadecyl, octadecyl and octadecenyl amines) in the form of the acetic salts, and 0.5 pound/ ton of furfural extract of FCC light cycle oil, having a boiling range of 600-800 F. and containing about 81% polycyclic compounds of at least three rings, including acenapthalenes, alkylfluorenes, phenanthrenes, pyrenes and higher homologues, 12.6% sulfur analogues, and about 2% alkylnaphthalenes and alkylindans. The -20 mesh fraction was conditioned with 0.8 pound/ton of starch and 0.1 pound/ ton of the mixture of amine collector reagents. The fractions were recombined and added to a Fag flotation cell along with some clear saturated brine. The slurry was then aerated from the bottom of the cell and as the froth formed at the surface it was removed carrying with it substantially all of the potash. 97.35% of the KCl was recovered, based on the amount of KCl in the ore pulp after desliming. The material analyzed 60.25% K 0.

In another test following the same procedure except that no aromatic auxiliary reagent was used, only 72.38% of the KCl was recovered. The material analyzed 61.71% K 0.

Examples II-VII The procedure of Example I was followed except that various polycyclic aromatic materials were substituted for the light cycle oil auxiliary reagent. The amounts of reagents used were the same as Example I, including the amount of auxiliary reagent. The following results were obtained.

Collier Heavy PD is a product of Collier Carbon and Chemical Corporation having a distillation range of 390 to 450 F. and described as predominantly aromatic polycyclic condensed rings, but containing 25% alkylnaphthalenes. The oil, which is from thermal cracking, is free pouring at 10 C.

Collier A500 is a product of Collier Carbon and Chemical Corporation described as heavy end of reformate and is predominantly aromatic condensed rings, containing about 62% tricyclic and tetracyclic compounds and 14% alkylnaphthalenes. It has a distillation range of 566 to 760 F. and viscosity SSU 100 F. of 63.

Panasol AN7 is an aromatic residual fuel oil, a product of Amoco Chemical Company having a distillation range of 468 to 713 F., viscosity SSU at 100 F. of 70, and pour point of 30 F. It is described as consisting of a mixture of predominantly tricyclic and tetracyclic compounds.

Provalent 4A is a product of Mobil Oil Company, described as a heavy aromatic oil having a distillation range of 417 to 734 F., viscosity SSU at 100 F. of 45, and pour point of 10 F. It contains about polycyclic compounds having at least three rings in the molecule, 7% alkylbenzenes and 34% alkylnapthalenes and alkylindans.

Examples VIII-X The procedure of Example I was followed except that the +20 mesh fraction was treated with a combination of the light cycle oil and an alkylnaphthalene or indane, as well as the amine mixture, and the 20 mesh fraction was treated with 0.13 lb./ton of the amine mixture as well as the starch. The following results were obtained.

Amount Purity, Recovery of Light Addltlonal Reagent Amount Percent Product, Cycle 01] (lb./ton) K20 Percent (lbJton) K20 VIII 0.25 Mixed methylnaphthalenes (B.P. 240.5-244 0)-... 0. 25 60. 49 93. 42 IX 0.125 Indane" 0. 375 60. 86 92. 36 X 0. 25 Panasol AN2 0. 25 60. 32 03. 93

50 Note.Panasol AN2 is a product of Amoco Chemical H Percent Purity of Company, having a boiling range of 370 to 550 F. and Auxlhary Reagent g zg sg l g i containing 45% alkylnaphthalenes, 20% alkylindans and alkyltetralins and 28% polyalkylbenzenes. Viscosity 37 O Bunker Heavy Cycle on 96.84 59.93 SSU at 100 r s as? as 0 ier 50 G Amoco Pauasol AN 7 96. as 60.17 Examples Xl-X Provalent 4A 96.32 61. 26 None 72. 38 61. 71

The procedure of Example I was followed except that the +20 mesh fraction was treated with 0.2 lb./ton of the amine mixture and a combination of the light cycle oil and as an additional reagent, petroleum fractions consisting predominantly of mixtures of alkylindans and alkylnaphthalenes. The 20 mesh fraction was treated with 0.5 lb./ton of starch and 0.1 lb./ton of the amine mixture. The following results were obtained.

Note.-Panasol ANS is a product of Amoco Chemical Company, having a boiling range of 400 to 750 F., viscosity of 46 SSU at 100 F., and containing 79% alkylnaphthalenes and 6% alkylindans and alkyltetralins.

Collier A4000 is a product of Collier Carbon and Chemical Corporation described as a reject stream from the hydrodealkylation of alkylnaphthalenes. It has a boiling range of 400 to 440 F., viscosity of 30 SSU at130 F., and contains 45% alkylindans and alkyltetralins, 45% alkylbenzenes and 5% naphthalene.

Although the examples illustrate the recovery of potash from potash ore, the novel flotation reagents of the present invention can also be used in the recovery of other desired mineral values by froth flotation procedures, such as the recovery of spodumene from silica.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. The method of obtaining potash from potash ore by froth flotation which comprises comminuting said potash ore, pulping the comminuted ore with brine, treating the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent and a polycyclic aromatic hydrocarbon auxiliary reagent having three to five rings in the molecule and having a distillation range within about 500- 800 F., subjecting said treated ore pulp to a froth flotation cell, and recovering said potash from said flotation cell.

- 2. The method according to claim 1 in which said potash ore is comminuted by grinding to a particle size of at least about 8 mesh.

3. The method of obtaining potash from potash ore by froth flotation which comprises comminuting said potash ore, pulping the comminuted ore with brine, treating the resultant ore pulp with a flotation reagent comprising an admixture of a long chain aliphatic amine collector reagent, a polycyclic aromatic hydrocarbon auxiliary reagent having three to five rings in the molecule and having a distillation range within about 500-800 F., and at least one material selected from the group consisting of indane, alkylindans in which said alkyl substituents have from one to about eight carbon atoms, alkylnaphthalenes and the hydrogenated derivatives thereof, in which said alkyl substituents have from one to about eight carbon atoms, subjecting said treated ore pulp to a froth flotation cell, and recovering said potash from said froth flotation cell.

4. The method according to claim 3 in which said potash ore is comminuted by grinding to a particle size of at least about 8 mesh.

5. The method according to claim 3 in which said polycyclic aromatic hydrocarbon auxiliary reagent is a mixture of predominantly tricyclic and tetracyclic hydrocarbon compounds.

6. In the method of recovering potash from potash ore by the froth flotation of an ore-brine pulp using a long chain aliphatic amine collector reagent, the improvement which comprises employing as an auxiliary reagent a polycyclic aromatic hydrocarbon oil having three rings in the molecule and having a distillation range within about 500-800 F.

7. The method according to claim 6 in which said aromatic hydrocarbon oil has a viscosity of less than about 100 SSU at 100 F.

8. In the method of recovering potash from potash ore by the froth flotation of an ore-brine pulp using a long chain aliphatic amine collector reagent, the improvement which comprises employing as an auxiliary reagent an admixture of a polycyclic aromatic hydrocarbon oil having three to five rings in the molecule, and having a distillation range within about 500-800 F. and at least one material selected from the group consisting of indane, alkylindans in which said alkyl substituents have from one to about eight carbon atoms, alkylnaphthalenes and the hydrogenated derivatives thereof, in which said alkyl substituents have from one to about eight carbon atoms.

9. The method according to claim 8 in which said polycyclic aromatic hydrocarbon oil is a mixture of predominantly tricyclic and tetracyclic hydrocarbon compounds.

10. The method according to claim 8 in which said admixture has a viscosity of less than about SSU at F.

References Cited UNITED STATES PATENTS 1,43 8,435 12/ 1922 Frederick 209-166 1,476,530 12/ 1923 McCullough 209-166 1,577,328 3/1926 Lewis 209-167 1,590,196 6/1926 Klees 209-166 3,016,143 1/1962 Trachta 209-166 3,059,774 10/ 1962 Wilson 209-166 3,149,788 9/1964 Wilson 209-166 FOREIGN PATENTS 1,008,222 5/ 1957 Germany.

HARRY B. THORNTON, Primary Examiner. R. HALPER, Assistant Examiner.

Claims (1)

1. 6. IN THE METHOD OF RECOVERING POTASH FROM POTASH ORE BY THE FROTH FLOTATION OF AN ORE-BRINE PULP USING A LONG CHAIN ALIPHATIC AMINE COLLECTOR REAGENT, THE IMPROVEMENT WHICH COMPRISES EMPLOYING AS AN AUXILIARY REAGENT A POLYCYCLIC AROMATIC HYDROCARBON OIL HAVING THREE RINGS IN THE MOLECULE AND HAVING A DISTILLATION RANGE WITHIN ABOUT 500*-800*F.