US2633241A

US2633241A - Froth flotation of iron-bearing minerals from feldspathic ores

Info

Publication number: US2633241A
Application number: US208948A
Authority: US
Inventors: Mason K Banks
Original assignee: Tennessee Valley Authority (ATV)
Current assignee: Tennessee Valley Authority (ATV)
Priority date: 1951-02-01
Filing date: 1951-02-01
Publication date: 1953-03-31
Anticipated expiration: 1970-03-31

Description

Patented Mar. 31, 1953 UNITED STATES PATENT OFFICE FRZQTH FLOTATION OFIRONeBEARING MIN- ERALS FROM FELDSPATHIC ORES Mason "K. Banks, Asheville, N. 0., assignor to Tennessee Valley Authority, a corporationof the United. States 9 Claims.

The inventionherein described maybe manufactured and usedby or for the .Governmentior governmentalpurposes without payment to me of i any royalty thereon.

This invention relates to the beneficiation of feldspathic ores. ."In concerns particularly the .removaI-of iron-bearing mineralsfrom such ores by froth flotation.

Feldsparforusein the glass trade must contain not .more than 0.1 per cent iron, as F6203, not more than 69 per cent silica, and. not less than 18.0 per-cent alumina. Sizespecifications require that the feldspar containnot more than3 per cent of plus20-.mesh.material and not more than per cent of minus 200+mesh material.

.Feldspar. for use in the ceramic trade is ground to pass a 200-mesh screen. The alumina content usually should not be less than 18 per cent, although a few manufacturers place this requirement as low as 1.7 per cent. The principal requirement as to iron content is removal of all particles which mightcausespotting or discoloring of fired ware. There is.no definite specification oniron content except that spotting or-discoloring dueto iron must notoccur-when ceramic ware is fired. However, thereis usually a close relationship between.spottingand iron content of feldspar recovered as a flotation concentrate. Iron, expressed.as F6203, usually must be less than 0.05 per cent if spotting is to be avoided, and often should be around-.0-.03 per cent.

.It is a general practice to recover feldspar from feldspathic ores as a flotation concentrate at minus 20 mesh. If produced for theglassmarket, the concentrate is then dried and shipped. If producedfor the ceramic market, the concentrate is dried, is sometimes blended with block spar, ground to'minus ZOOmesh, sized, and shipped.

Large deposits of alaskite, a feldspathic .ore, existin western North Carolina. This material is apegmatitic-granite, varying in texture from the coarseness oipegmatiteto'the fineness of granite. It is rather uniform in composition, comprising oligoclase. quartz, microcline, andmuscovite, with small amounts of garnet and biotite present, especially near the contacts.

Oligoclase is a soda-lime feldspar, and microcline is-a potash feldspar. Muscovite and biotite aremicaceous minerals. Biotite contains iron in its molecule. Muscovite, while it contains no iron sec. 266) in its molecule,.isfrequentlystained red or black by thin films of. iron oxide betweenthe laminae. Iron-containing garnets probably are present as almandite (3FeO:Al2Os 2SiOz) and/ or .andradite (BCaO-FezOs 3SiO2) An alaskite ore sample, typical .of thatnow being used in the production of feldsparin western North Carolina, had the following chemicalan- U. S. Patent No. 2,483,192 discloses a process for decreasingthe ferrous-metals silicates content of feldspathicore by pulping the orewith water, conditioning the pulped ore'in an acid medium at apI-I of 2.5-to5'.0 with asulionatedpetroleum hydrocarbon promoter with or without fuel oil'and a suitablefrother, subjecting the conditioned pulp to froth. flotation, and removing the froth flotation concentrate. Since alaskite and certain other feldspathic ores contain both micaceous materials and garnets, known to require, respectively, a cationic .and an anionic promoter for flotation, it might be expected-that such process would be inefiective for producing ceramic-grade feldspar by simultaneous removal of iron-bearing impurities of both types. Laboratory tests reported in Example I, below, and plant experience have tended to confirm this assumption.

A process now in use for the removal of ironbearing-impurities from feldspathic ores containing iron both asmicaceous materials and as garnets requires two flotation steps for iron removal. In the first step, the ground, screened, and deslimed ore is conditioned at about per cent solids with appropriate amounts of sulfuric acid, fuel oil, a cationic promoter, usually a long-chain fatty-acid amine, and a suitable frother, usually a crude or refined pine oil. The conditioned pulp is then diluted and subjected t frothfiotation, and

a flotation concentrate consisting mainly of micaceous impurities is removed.

In the second step, the resulting flotation tailing is partially dewatered in a hydraulic classifier and then conditioned at about 65 per cent solids with appropriate amounts of fuel oil, sulfuric acid, an anionic promoter, which may be a sulfonated petroleum hydrocarbon, and a suitable frother. The conditioned pulp is then subjected to froth flotation, and the flotation concentrate, consisting mainly of garnet impurities, is removed. This process has proved successful for the production of ceramic-grade feldspar from such ores but, since two separate flotation steps are required to reduce the iron content to sufficiently low value, it is necessarily complicated and requires equipment, reagent, and handling expense exceeding that of a one-step process.

The prior art, however, as typified by U. S. Patent No. 2,483,192, column 4, lines 74-75 ff., and by an article entitled F1otationchemicals for non-metallic minerals, Rock Products 49, Sit-93+, December 1946, has taught that cationic and anionic flotation promoters cannot be used together in a single step because they are antagonistic to each other and require different conditions for effectiveness.

It is an object of this inventionto provide a onestep flotation process for the removal of iron from feldspathic ores containing iron both as micaceous materials and as garnets.

Another object is to provide a method for the production of ceramic-grade feldspar from feldspathic ores containing both micaceous materials and garnets.

Other objects and advantages will become apparent as this disclosure proceeds.

I have found that these objects may be attained by simultaneously conditioning a suitably ground and deslimed pulp of feldspathic ore containing iron both as micaceous materials and as garnets with suitable amounts of a cationic promoter comprising a long-chain fattyacid amine and with an effective amount of an anionic promoter, namely, a material selected from 'the group consisting of sulfonated oleic acid, sulfonated red oil, sulfonated methyl esters of red oil, and Turkey red oil, in an acid medium, with or without suitable frothing and/or oiling agents; subjecting the conditioned pulp to froth flotation; and removing the iron-bearing minerals in froth as a flotation concentrate. A flotation-cell tailing consisting essentially of feldspar and quartz is then withdrawn and is conditioned with hydrofluoric acid and a long-chain fatty-acid aminepreferably the same amine used in floating the iron-bearing mineralswith or without suitable frothing and/or oiling agents. This pulp is then subjected to froth flotation, and feldspar sulficiently free from iron to pass specifications for ceramic-grade material is recovered as a flotation concentrate.

- The drawing submitted herewith is a diagrammatic flowsheet of a. process embodying principles of my invention. Steps which are novel in themselves are indicated by solid lines, and other steps which may be necessary in the process but which are, in themselves, old in the art are indicated by broken lines.

Reference to this flowsheet shows that alaskite or other feldspathic ore containing iron both as micaceous materials and as garnets is fed into a crusher. A jaw crusher usually is used for the purpose of reducing the lumps of ore to such sizes as can be efficiently handled by a grinding mill. A suitable quantity of water is added to the crushed ore and it is passed to a grinding mill, preferably a rod mill, where the ore is ground to pass a 20-mesh screen. The ground ore is passed to a suitable means for removing 20mesh oversize material, preferably a 20-mesh screen, and any oversize is removed. That fraction of the ground ore of sizes passing the 20-mesh screen is then advanced to a means for removing slimes, preferably a hydraulic classifier, and substantially all minus 325-mesh material is separated from the bulk of the ore. The steps just described are old in the art and are preferred merely because of cheapness or convenience. Any equivalents therefor may be substituted if desired, as it is merely necessary that the ore be reduced to particles of such size as to pass a 20- mesh screen, and that minus 325-mesh slimes be removed.

A pulp of the resulting ground, deslimed ore containing about 55 per cent to 65 per cent solids is introduced into a conditioner. Sulfuric or other acid or acid salt yielding a free acidic radical in solution is added in quantity sufficient to maintain the pulp in the pH range from about 2.0 to 3.6 and preferably in the range from about 2.0 to 3.1. I have found that iron removal is satisfactory up to pH 3.6 and above, but above 3.6 excessive quantities of feldspar and quartz will be floated with the iron-bearing minerals. A material selected from the group consisting of sulfonated oleic acid, sulfonated red oil, sulfonated methyl esters of red oil, and Turkey red oil, is added as anionic-flotation promoter, and a long-chain fatty-acid amine or mixture of such amines or water-soluble salts of such amines yielding the amines in solution is also added to serve as cationic-flotation promoter.

A frothing agent such as pine oil may be required when certain sulfonated fatty acid materials are used, and is also added if necessary. An oiling agent such as fuel oil also may be added if desired.

The resulting conditioned pulp is then passed to a flotation cell and is adjusted to a concentration of about 25 per cent solids by the addition of water. The resulting pulp is subjected to froth flotation, and iron-bearing minerals of both micaceous and garnet types are removed in froth as a flotation concentrate.

The amount of each class of promoter required to be added in the conditioning step described above will depend on a number of factors, but mainly on the amount of iron-bearing minerals to be removed from the ore and on the degree of purity of reagents employed. In general, about 0.5 to 2.0 pounds of sulfonated fatty acid, acids, or fatty-acid esters and about 0.1 to 0.5 pound of long-chain fatty-acid amine or amines will be required per ton of ore treated.

As used in this specification, the term longchain sulfonated fatty acid refers to compounds having 14 or more carbon atoms in the fatty-acid radical, and since the sulfate group often is present to some extent in commercial sulfonated fatty acids the term is not intended to exclude the presence of acids having the sulfate group present as such. The term longchain fatty-acid amine refers to such amines having 14.- or more carbon atoms in the fattyfonatedti longgchadnz fatty acidt'. namelm ma.-

methyllesterss. o-fqfredi 011;. andiTurkeyrredioil; are;

' not antagonistic to cationic promoters comeprising a long-chain fatty-acid amine, :bntteach exerts its full selective-e flotation effect under identical. conditions... Thesepromoters. may, thereforebe: used together in a single flotation steps Theaexpectedantagonism is not detectame,- although other anionic promoters such as sulfonated petroleum oils and.many sulfonat'ed long' chain' fatty-acid materials are: antago:-- nistic to: long-chain: fatty-acid amines:- under similar conditions: V I.

, After removal. of iron-bearing minerals, by. flotation, 'the resulting flotation tailing .is passed to a means for rem'oving water, preferably. a. hydraulic. classifien. It..isv there. concentratediito. about". 50 per. cent; solids. by; removing water: and. is; passed. to. a. second. conditioner; The. pulp: is: therev conditioned" with. suitable;

amounts. off" hydrofluoric. acid', a; long-chain; fattyeacidi, amine. (preferably the: same; used. in

the iron-removal'step describedaldove), a suitable .frothing agent, and fuel oil. The resultingconditioned pulp is dilutedjiwithi water if 'neces s'ary and" is then subjected to" froth. flotation. Feldspar sufficientlylowiinyiron" for use iIIillhE ceramic trad'ezis thereby-recovered in" froth as a flotation'..concentrate.

Examples. are. given below illustrating quantie ti'es.of .Treagents. andfcondi'tien-s which have .proved. eifective for. the. productionv of? ceramic-grade; feldspar from ores containing; iron both as; micaceous materials and as garnets; OZtlier-ex amples" illustrate; the failure: of methods of the prior 'artt0 produce" such results: H

The Examples I throuehVII describe laboratory-scale batchwise tests. In each of these examples'the following procedure wasusedin" preparing theorefor testing? (a)? A.600'-gram sample of. crushed' 'ore. was wetground at 25 per cent solids in a rod mill for 2 to13.minutes..

(bi)' Thevgroundl. ore was passed through. a.

mesh screen, and the 20 meshrofversize-was discarded.

(c) The. minus: 20-mesh. materiaL was. deslimed by washing .three times-.ona .325-mesh screen.

The quantities of reagents given in all the following examples are in termssoflpounds of reagentsperton of feed to thegrinder.

Trade names are givemfors the; reagents used,

since pure compounds areseldom employed as flotation promoters,,and..it.may -be,necessartg to vary the amounts slightly if other approximately equivalent materials are substitutedfor. those d6:- scribedii The? materials; identified BXIJ'tI'iGfi"? tradenames, areidefinedaszfollowsz at 7.0 per cent solidsl w-ith.0.35. lb. /ton.sulfuric.

(f)t Amine:- 2217iisr: a2. mixtures ofi' lona'eeliain fatty-acid a-minesi prepared from tall oil.

(g) Armac T is a mixture of water-soluble acetate salts of hexadecyl, octadecyl, and octadecenyliamine prepared from tallow.

(78)1 Reagent-r 825? is a sulfonated petroleum hydrocarbon material of; the oil soluhle; water dispersibleemahogany type.

(i): Aerofi'oat 31is.- a.-frotliing 'agentwhich some prisesabout- 6? per cent thiocarbani-lid dis solvedin dicresyldithio phosphoric acid;

(7') B'-.2'3is' a syntheticfrother consi'stingessentially of higher alcohols.

EXAMBLE I.

The processor-UT SE 234835192 wastestedtowzle tel-mine its effectivenessswith':alaskite. The ore used in this test contained 0.41 per cent FezOs; Thepronioterrused wasReagentBZd? Thedeslimed'; ore: was: conditioned for -6" minutes at" 70 per" centtsolidshwith: 0535 lbi/ton sulfuric: acid? 112:11'01/ ton-.R'eagent 825; 025 lbr/ton Aerofioat 3.l;andj 0:50. lid/ton of. fuell'oil. The-pulp was" diluted" toflotationdensity (about 25" percent:

: solids), ,subjectedtdfrot-h flotation; and'thefroth concentrate. was separated:

Visual examination of the celli tailing; corrtaining feldspar-and quartz; showed pthatremoval 'offtlie" garnet impurities-was good; but that re moval" of misaceous" material was incomplete;-

maze lz-A wt Per" Per Por Per" Feed-3 600" i Isou'concentrate 36'; .2 Feldspanconeentrate: 339 I l 66.13.- Quartztail. 135' 9639" Loss 1 9O 1....-.

I gloss represents .plus 20:mcsh.material, animinusl325=meslrmm en The feldspar concentrate produced by this process met the specifications for glass-grade feldspar.

The feldspar, however, contained numerous black particles of biotite, as well as clear mica; and would not have been suitable for use in high-grade ceramic ware.

EXAIWPLE II Inanother test, reagent BL-408 was used instead' of Reagent 825 with the same ore used in Example I.

The.-.deslimed.nre.was conditioned i011. (iminutes:

acid, I12 lb./to-n RD-408;and 015' lbT./ton.fuel oil. The pulp was subjected to froth flotation, and' tlie-frotliwas-separated? Separation ofigarnets was' go-odhut mica; separation w-as=ve1';, -@poorr The ceiljtailing fCOIIlJEiHBfibDJZlQ per-cent Eezfim.

The eellltailing .wastthenlconditioned with, 15* lb.Aton.. hydrofluoric. acid,., 0.5. lla/toninel oil, 0.25:. lli/t'on B -23lf"and0'll4"Ill/ton Armac Tiand subjected to froth flotation. Separation of felii spar from quartz was poor."

7 The results of this test are tabulated below: Separation of feldspar from quartz in the sec- Tabze ond flotation step was incomplete, and the feldspar concentrate contained much of the mica that had not been removed in the first flotation Wt. Per Per Per Per Ste cent cent cent cent Wt. A1203 F6203 siol Results:

Table 4-11 Feed 600 100.0 0.41 tii e't 3i? 5%; "0'50 e SD81 (30110611 8. Quartz tail 198 33.0 0.091 89.7 31 55, LOSS 77 Wt. A1203 F9203 s10,

The feldspar concentrate produced in this eed egg 102.3 0.41 0 a test did not meet speclflcat ions for either glass f gfi g f 240 4M mg 0.140 650 grade material or ceramic-grade, because of 15 Quartz tail 245 40.8 0.081 35.0 high F8203 and micaceous impurities. 91 or III E LE V In this test, my preferred procedure was followed. Deslimed pulp was conditioned for 10 The following Table 5-A gives the results of minutes at 60 per cent solids with 0.35 lb./ton sulfuric acid, 1.2 lb./ton BL-408, 0.5 lb./ton fuel oil, and 0.32 1b./ton Armac T. The conditioned pulp was subjected to froth flotation, and the iron-bearing froth was separated. Removal of both garnets and mica was very good. The cell tailing contained 0.0278 per cent Fezos.

The cell tailing was then conditioned at 55 per cent solids with 1.5 lb./ton hydrofluoric acid, 0.5 1b./ton fuel oil, 0.25 lb./ton B-23, and 0.14 lb./ton Armac T, and the conditioned pulp was subjected to froth flotation.

tests which show the iron-removal efliciency of various sulfonated fatty-acid reagents in com-.

bination with long-chain fatty-acid amines. Table 5-B gives the reagent combinations that were used in each of the tests reported in Table 5-A.

Results tabulated under test 5-b were obtained by the use of Ahcol 385, prepared by sulfonating tall oil. These particular results were very good but were obtainable only when the ore was of {such nature as to require restricted amounts of anionic and cationic promoters.

Results: When larger amounts of reagent were necessary, Table it was found that a definite antagonism existed between such sulfonated tall oil and long-chain Wt Per Per Per Per fatty-acid amines.

r. ii; E 21 6, In each of these tests conditioning of the deslimed ore was carried out at 55 per cent solids.

Feed 000 100.0 0.41 Iron concentrate- 5.8 Table 5-A eldspar concentr 358 59.7 19.5 0.032 66.8 Quartz tail 13 21.7 0. 024 97.0 oss 12.8

Percent Percent Percent Percent Test N0. F6203 in F020; in of F8203 The feldspar concentrate met specifications feed Feed Com Tail tall removed for ceramic-grade feldspar in all respects. Moreover, the separation of feldspar from quartz in M8 100 no no M67 8% the final flotation step was highly selective, as s-b 0. 51 13.0 ;7.5 0.063 00.4 evidenced by the high SiOz content (97%) of the it: 335 m0 3;; 3;; 2,;323 33;; quartz tail. 5-e 0.41 100 12.8 76.0 0. 005 88.1

EXAMPLE-IV 1 Preconditioned for 3 minutes with 2.0 lb. ton NaOH rio to In this test, the 1dent1ca1 procedure followed desliming, I p r Table 5-B' Reagents-1b.]ton Test NO. F 1

H4804 Amomc promoter Cationic promoter Frother g 5-a 0.8 2.0 Turkey red oil. 0.25 Amine 22 T 0.6 pine oi1. 5b 0.6 15Ahcol 5 0.1 Armac T"... 0.3 pine oil 0.5 l5Ahco1550...- 0.2Armac do 41-0.--. 0.9 10Ahco1575" 0.3A1mac T 5e 0.35 RL-40 0.32A.1mac T 0.5

in Example III was used, except that 1.2 lb./ton EXAMPLE VI Table 6-A gives the results of tests in which the effect of pH on iron-removal efficiency was investigated. The alaskite ore used in these tests contained 0.43 per cent FezOa. In these tests the deslimed ore was conditioned for 10 minutes at per cent solids with varied amounts of sulfuric acid, 0.85 lb./ton BL-408, 0.5 lb./ton fuel oil, and 0.32 lb./ton Armac T. Following conditioning, the pulp was subjected to froth flota= tion for 3 minutes at 25 per cent solids.

11 red. oil, and with an effective amount of a cationic promoter comprising a long-chain fattyacid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; removing resulting froth containing both micaceous materials and garnets; removing water from the resulting flotation tailing to a concentration of about 50 per cent solids; conditioning the resulting concentrated tailing with effective amounts of hydrofluoric acid, a long-chain fatty-acid amine, and a frothing agent; subjecting the conditioned tailing to froth flotation; and recovering ceramicgrade feldspar in froth as a flotation concentrate.

2. A process for the production of ceramicgrade feldspar from a feldspathic ore containing iron both as micaceous materials and as garnets which comprises mixing such ore in a ground, deslimed state with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a suificient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals in solution to produce a pH of about 2.0 to 3.6 in the pulp, with an efiective amount of an anionic promoter comprising sulfonated methyl esters of red oil, and with an effective amount of a cationic promoter comprising a long-chain fatty-acid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per .cent solids; subjecting the resulting diluted pulp to froth flotation; removing resulting froth containing both micaceous materials and garnets; removing water from the resulting flotation tailing to a concentration of about 50 per cent solids; conditioning the resulting concentrated tailing with effective amounts of hydrofluoric acid, a long-chain fatty-acid amine, and a frothing g'agent; subjecting the conditioned tailing to froth flotation; and recovering ceramic-grade feldspar in froth as a flotation concentrate.

3. A process for the production of ceramicgrade feldspar from a feldspathic ore containing iron both as micaceous materials and as garnets which comprises mixing such ore in a ground, deslimed state with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a ;sufiicient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals-in solution to produce a pH of about 2.0 to 3.6 in the pulp, with an effective amount of an, anionic promoter comprising a material selected from the group consisting of sulfonated oleic acid, sulfonated red oil, sulfonated methyl esters of red oil, and Turkey red oil, and with an effective amount of a cationic promoter comprising a mixture of-hexadecyl, octadecyl, and octadecenyl amines; diluting the resulting conditioned pulp with water to a concentration of about 25 per erals from a feldspathic ore containing iron both as micaceous materials and as garnetswhich comprises pulping such ore as minus 20-mesh deslimed particles with water to form a pulp containing about 55 to 65 per cent solids; simul taneously conditioning the resulting pulp with a sufficient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals in a solution to produce a pH of about 2.0 to 3.6 in the pulp} with an effective amount of an anionic promoter comprising a material selected from the group consisting of sulfonated oleic acid, sulfonated red oil, sulfonated methyl esters of red oil, and Turkey red oil, and with an effective amount of a cationic promoter comprising a longchain fatty-acid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; and removing the resulting froth containing both micaceous materials and garnets.

5. A process for removing iron-bearing mineral from a feldspathic ore containing iron both as micaceous materials and as garnets which comprises pulping such ore as minus 20-mesh deslimed particles with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a suflicient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals in a solution to produce a pI-l of about 2.0 to 3.6 in the pulp, with an eifective amount of an anionic promoter comprising sulfonated oleic acid, and with an effective amount of a cationic promoter comprising a long-chain fatty-acid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; and removing the resulting froth containing both micaceous materials and garnets.

6. A process for removing iron-bearing minerals from a feldspathic ore containing iron both as micaceous materials and'as garnets which comprises pulping such ore as minus 20-mesh deslimed particles with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a suflicient amount of a material selected from the group consisting of water-soluble acids and acid saltsyielding free acidic radicals in a solution to produce a pH of about 2.0 to 3.6 in the pulp, with an eifective amount of an anionic promoter comprising sulfonated red oil, and with an effective amount of a cationic promoter comprising a long-chain fatty-acid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; and removing the resulting froth containing both micaceous materials and garnets.

7. A process for removing iron-bearing minerals from a feldspathic ore containing iron both as micaceous materials and as garnets which comprises pulping such ores as minus 20-mesh deslimed particles with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a sufficient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals in a solution to produce a pH of about 2.0 to 3.6 in the pulp, with an effective amount of an anionic promoter comprising sulfonated methylesters of red oil, and with an effective amount of a cationic promoter comprising a long-chain fattyacid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; and removing the resulting froth containing both micaceous materials and garnets.

8. A process for removing iron-bearing minerals from a feldspathic ore containing iron both as micaceous materials and as garnets which comprises pulping such ore as minus ZO-mesh deslimed particles with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a sufficient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals in a solution to produce a pH of about 2.0 to 3.6 in the pulp, with an effective amount of an anionic promoter comprising a material selected from the group consisting of sulfonated oleic acid, sulfonated red oil, sulfonated methyl esters of red oil, and Turkey red oil, and with an effective amount of a cationic promoter comprising a mixture of hexadecyl, octadecyl, and octadecenyl amines; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; and removing the resulting froth containing both micaceous materials and garnets.

9. A process for the production of ceramicgrade feldspar from a feldspathic ore containing iron both as micaceous materials and as garnets which comprises mixing such ore in a ground, deslimed state with water to form a pulp containing about 55 to 65 per cent solids; simultaneously conditioning the resulting pulp with a sufficient amount of a material selected from the group consisting of water-soluble acids and acid salts yielding free acidic radicals in solution to produce a pH of about 2.0 to 3.1 in the pulp, with an effective amount of an anionic promoter comprising a material selected from the group consisting of sulfonated oleic acid, sulfonated red oil, sulfonated methyl esters of red oil, and Turkey red oil, and with an effective amount of a cationic promoter comprising a long-chain fatty-acid amine; diluting the resulting conditioned pulp with water to a concentration of about 25 per cent solids; subjecting the resulting diluted pulp to froth flotation; removing resulting froth containing both micaceous materials and garnets; removing water from the resulting flotation tailing to a concentration of about per cent solids; conditioning the resulting concentrated tailing with effective amounts of hydrofluoric acid, a long-chain fattyacid amine, and a frothing agent; subjecting the conditioned tailing to froth flotation; and recovering ceramic-grade feldspar in froth as a flotation concentrate.

MASON K. BANKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,132,902 Lenher Oct. 11, 1938 2,297,689 OMeara Oct. 6, 1942 2,395,475 Gibbs et a1 Feb. 26, 1946 2,433,192 Gieseke Sept. 27, 1949 2,578,790 Duke Dec. 18, 1951 FOREIGN PATENTS Number Country Date 105,712 Great Britain Nov. 17, 1938 OTHER REFERENCES Bulletin of American Ceramic Society, vol. 18, No. 8, August 1939, pages 286-292.

Claims

1. A PROCESS FOR THE PRODUCTION OF CERAMICGRADE FELDSPAR FROM A FELDSPATHIC ORE CONTAINING IRON BOTH AS MICACEOUS MATERIALS AND AS GARNETS WHICH COMPRISES MIXING SUCH ORE IN A GROUND, DESLIMED STATE WITH WATER TO FORM A PULP CONTAINING ABOUT 55 TO 65 PER CENT SOLIDS; SIMULTANEOUSLY CONDITIONING THE RESULTING PULP WITH A SUFFICIENT AMOUNT OF A MATERIAL SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE ACIDS AND ACID SALTS YIELDING FREE ACIDIC RADICALS IN SOLUTION TO PRODUCE A PH OF ABOUT 2.0 TO 3.6 IN THE PULP, WITH AN EFFECTIVE AMOUNT OF AN ANIONIC PROMOTER COMPRISING A MATERIAL SELECTED FROM THE GROUP CONSISTING OF SULFONATED OLEIC ACID, SULFONATED RED OIL, SULFONATED METHYL ESTERS OF RED OIL, AND TURKEY RED OIL, AND WITH AN EFFECTIVE AMOUNT OF A CATIONIC PROMOTER COMPRISING A LONG-CHAIN FATTYACID AMINE; DILUTING THE RESULTING CONDITIONED PULP WITH WATER TO A CONCENTRATION OF ABOUT 25 PER CENT SOLIDS; SUBJECTING THE RESULTING FROTH PULP TO FROTH FLOTATION; REMOVING RESULTING DILUTED CONTAINING BOTH MICACEOUS MATERIALS AND GARNETS; REMOVING WATER FROM THE RESULTING FLOTATION TAILING TO A CONCENTRATION OF ABOUT 50 PER CENT SOLIDS; CONDITIONING THE RESULTING CONCENTRATED TAILING WITH EFFECTIVE AMOUNTS OF HYDROFLUORIC ACID, A LONG-CHAIN FATTY-ACID AMINE, AND A FROTHING AGENT; SUBJECTING THE CONDITIONED TAILING TO FROTH FLOTATION; AND RECOVERING CERAMICGRADE FELDSPAR IN FROTH AS A FLOTATION CONCENTRATE.