US2373688A - Flotation of ores - Google Patents

Description

metallic mineral ores to more economically reore economically feasible.

Patented Apr; 17, 1945 i UNITED STATES PATENT OFFICE FLOTATIGN OF @3353 Walter E. Keck, Hancock, Mich, assignor to v Sherwood Refining Company, Inc., Englewood, N. J.,a corporation of New Jersey No Drawing. Application May 16,1942,

' Serial No. 443,282 g 14 Claims. '(C l. 209-166) This invention relates to the froth flotation of ores and has particular reference to novel flotation agents -and-to processes for treating noncover value-bearing minerals therefrom.

The non-metallic mineral ores have a tendency toslime badly and for that reason are difllcult to float with the knowntypes of flotation agents. The presence of slimes in the ore pulp often-renders it impracticalto use such materials as oleic acid, for the reason that oleic acid is a strong floating agent and a collector for 'nearly'all slime minerals so that a dirty, tough and tenacious froth is formed which cannot be freadily broken. Slimes are present in substantially all ore pulps by theconventionaf methods of preparing ore for flotation.

with mahogany sulfonates and oilsoluble sulionic acids derived from petroleum, either alone or in combination with other"type s of flotation agents.

, stockwhich are oil-soluble, substantially insoland theamount ofslimes is materially increased uble in water, but dispersible in water. The reflned mahogany sulfonates which are preferably used in flotation operations are characterized by a'wine color. These mahogany sulfonates form dispersions similar to colloidal gels when used with water in a concentration of about 12%, and readily disperse upon agitation in hot water.

Upon dilution of the dispersion, the viscosity decreases until the dispersion becomes very fluid.

The mahogany sulfonates preferably are 'dis- Another difllculty which is encountered in the commercial flotation of non-metallic ores is the parsed in hot water and then boiled for about ten minutes. The dispersion; at any desired temperature, is added to the flotation system. The

lack -of flotation agents which permit an economical recovery of the valuable portion of the ore. Inasmuch as the finished products of such non-metallic'ores are usually low priced, it is necessary to use inexpensive flotation agentsin order to make recovery of the valuable portion of the Thus. flotation of non-metallic mineral ores, from a practical standpoint, is complicated by thenecessity of finding suitable, cheap flotation agents, which may-housed in relatively small quantities and whichare not affected by the presence of slimes. I

Anv object 01' the present invention is to provide methods and flotation agents which have the necessary characteristics for the economical flotation of such ores.-

Another object of the invention is' to provide novel flotation agents which function effectively in the presence of slimes.

active principles of the mahogany sulfonates appearto be the sodium sulfonates or sulfonlc acid groups.

The term petroleum sulfonicacids as used herein also refers to the oil-soluble, water-dis-v persible and substantially water-insolublesulfonic acids obtained from theoil layer resulting from the sulphonation of petroleum fractions.

- surface of the already coated particle, and thus An additional objector the invention .is to pro- Vide flotation agents which are selective in separating-valuable non-metallic components 01 an ore from valueless n'on metalli'c components.

Other objects of the invention will become apvention.

In its most general-aspects, the invention involves the flotation of non-metallic mineral ores Mahogany sulfonates and petroleum sulfonic acids exert a strong collectingaction not only on metallic minerals, but also on non-metallic mine 1 erals. It has been found that the collecting action of the mahogany sulfonates or petroleum suli'onic acids is materially enhanced by the presence of hydrocarbons such for example, fuel oil, which apparently forms an additional coating on the renders it more readily floatable. Fuel oil controls the quality of froth and prevents the inclusion ofunwanted minerals in thefroth inasmuch as fuel oil is, in itself, an excellent collector. Many of the advantages or the mahogany sulfonates and the oil-soluble petroleum sulfonic acids arise from'the fact that they are excellent emulsifiers for fuel oilwhich is one oi the most ,powerfuland cheapest collectors known, but heretofore little used because of lack of a satisfactory emulsifier.

It has been found that mahogany sulfonates or petroleum sulfonic acids alone or in combination mahogany sulfonates, as used herea with other classes of reagents, such as frothers, for example, pine oil, cresylic acid, conditioners, such as lime and oda ash, depressors, such as sodium silicate, strong acids, for example, nitric, sulfuric, hydrochloric, hydrofluoric and phosphoric acid, metallic salts, such as calcium chloride, ferrous or ferric sulfates, and aluminum sulfate, under proper conditions, improve flotation.

In addition to the characteristics noted above, mahogany sulfonates and the oil-soluble petroleum sulfonic acids are not strong frothers in the concentrations-and under the conditions used, and may be used in flotation operations without being adversely affected by the presence of slimes. They, also, often act as froth conditioners inasmuch as they have a beneficial efiect on the froth produced by other reagents.

The mahogany sulfonates and petroleum sulfonic acids form most economical flotation agents .for the reason that they are by-products of pe troleum refining operations and are available in quantity at relatively small cost under normal economic conditions.

In accordance with the present invention, mahogany sulfonates and oil-soluble petroleum sulfonic acids have been successfully used in the flotation-of a great manyof the non-metallic minerals such as, for example, epidote. gypsum,

barite, fluorspar, calcite, limestone for the manufacture of Portland cement, and phosphate rock.

for industrial use and of its elimination from iron ores where its sulphur content is extremely detrimental to the desired properties of iron and steel prepared from these same iron ores. As an example, in the Menominee range of Michigan there are large tonnages of otherwise useful ores which cannot be mined andsmelted because of their excessively large sulphur content.

The gypsum material for this experiment was obtained from a gypsum producing property in Michigan. It was composed mainly of white gypsum with smaller quantities of dark colored minerals. The material was ground to -65 mesh size in a rod mill and was conditioned with 0.80 pound of mahogany sulfonates at about 35% solids content for five minutes. 0.1 pound of pine oil was added, the pulp was diluted to about 23% solids concentration and the pulp floated in a mechanical flotation machine for flve minutes. Under these conditions the gypsum floated readily and 67% of the feed to flotation was collected in the froth.

In the treatment of some of these ores, ithas been determined that by proper control of condit1ons during flotation, the valuable portion of the ore may be floated or depressed as may be desired, therefore indicating the versatility of mahogany sulfonates in flotation operations. Illustrative of the treatment of various types of non-metallic mineral ores with mahogany sulfonates, the following examples are given.

EXAMPLE 1FLOTATION or Ermo'rs The epidote for this experiment was obtained from a pilot table in a mill operated on Michigan native copper ore. This pilot table product, con- 3 sisting largely of epidote was ground in a rod mill until all of it was -65 mesh size. Anaqu'eous I mixture of the ground material containing about tests are shown in the following table:

I Table A I Per cent Addition or activating reagent e idote ooted 0.42 pound Cock. 77.0 0.50 pound H1804 92.0 0.50 pound ,FeSOM'HzO 88.0 0.50 pound Ah(SO4)z.18H:O I 96.0

EXAMPLE 2-FLQTATION or GYPSUM I The flotative properties of gypsum are of interest both from the standpoints of-its beneficiation The results of these in I mahogany. sulfonates, the quantity of material floated was reduced to about 23% of the weight of the feed. This floated material contained nearly all of the dark colored minerals, whereas the tailing was composed of white gypsum.

,EXAMPLE 3-FLOTATIQN or BARITE The material for this experiment was composedalmost entirely of barite. This material was crushed to pass 10 mesh and then was ground to a fineness such that nearly all of it passed through a 65 mesh screen. An aqueous pulp of the ground material was conditioned with 0.8 pound of mahogany sulfonate at a concentration of about 35% solids for five minutes and 0.1 pound pine oil was added. The pulp was diluted to about 23% solids and floated in a mechanical flotation machine for flve minutes. Under these conditions, the barite floated readily, about 90% of the weight of the feed to'flotation being collected in the froth.

EXAMPLE 4-FLOTATION or FLUORSPAR pulp containing about 35% .of the ground ore was conditioned with 2 pounds of mahogany sulio nates and 2 pounds of fuel oil for flve minutes. 0.1 pound of pine oil was added to the pulp and the pulp was diluted to about 23% solids. The diluted pulp'was floated in a mechanical flotation machine for four minutes. The fluorspar floated well under these conditions and considerable separation of this mineral from calcite was made. The froth or concentrate contained 4.4% calcite, whereas the tailing contained 9.9% of the same mineral. Likewise a good separation of fluorspar from quartz was obtained, as shown'by the fact that the froth or concentrate contained 2.5% silica and thetailing contained 14% silica. ExAMrLa '5-FLOTATION or Caron-1:

aa racse ore at about 35% solids concentration was conditioned with0.40 pound of mahogany sulronate for live minutes. 0.1 pound of pine oil was add-. ed to the conditioned pull). the pulpdiluted to about 23% solids and the pulp was floated in a mechanical flotation machine for flve minutes. About 59% of the feed to flotation was collected I inthe froth.

I Under the same conditions, except that one pound of mahogany sulfonates was added with 4 pounds of fuel oil, 95% of the feed toflotatlon was collected in the froth. I

Exempt: 6-Fi.orArIoN or Lmssrom:

A. limestone. used in the manufacture of Portland cement was used for this experiment. The

limestone was taken from the feed to a commer- 1 the ore passed through a 200 mesh screen. A

pulp of this ore containing 35% solids was conditioned with 2 pounds of mahogany sulfonates' v and 2 pounds of fuel oil for live minutes. The conditioned pulp was then diluted to about'23% I solids concentration and floated in a flotation I machine {or eight minutes. With this flotation romeo- Quontitysnd kind 0mm Product; 3%? aim;

.i.slb.n.Po....-..---.--. .5 2g f1 3.41s. moo 1%,? 4 I 100. 3815301 {Conc.'- 13.2 '78; lail 2.8 3:

. b HF 1,5-4 I I 10o.

Cone 13.0 I 2.o1b.mso....... {Tail 3 5 31. 100.

It appears that the most desirable results, were obtained through the use of hydrochloric acid;

but-satisfactory results were obtained in substan-' twill: all instances with the various acidsindica e conditioned with 3 pounds of fuel oilat a concentration of about 60% solids for flfteen seconds and then 4 pounds of mahogany sultonates were procedure the froth or concentrate contained 76% added to the pulp and conditioning continued of lime in the flotation feed and the grade of this concentrate in respect to lime was 42%. The tailing contained 24% of the lime inthe feed and the grade of the tailing was 26.7% lime.

for an additional two minutes. pulp was diluted to about 23% solids, 2 pounds of sulphuric acid. were added and the pulp was floatedror,

seven minutes. With this method of'flotatiom,

-When the limestone was crushed, ground and 82.4% of the phosphorus content of the feed was the reagents were added in small increments and flotation was accomplished after each addition or the reagents, a very high recovery of the calcium carbonate was made; "I'heresultsof these tests are disclosed in the following table:

' collected in thefroth or concentrate and this concentrate had a grade of 12.7 in'respect to phos-.

phorus. The tailing from this flotation operation contained 17.6% of phosphorus in the feed and its grade was 2.2% phosphorus.

Exmrnl 7--F'r.ors'rron or Pnosrnsrr: Rocx I Table B I n d? msh r l'i i ilc" Ope a I Product 3 8 1:

so og. e ta 7 a inpulp suli. oil 31 pmm dhtrib.

2a 0.3a Condit 1 0.13 I -----do .s 0. 01 Flo t 2 44.9 15.0v 0.30 0.10 0.01 H! 2 48.4 32.6 0.3 0.08 0.01 Hi 2 48.7 37.5

, 0.2a 0.0a 0.01 to 2 I 37.4 11.0,

- v I 1.5 3.0 I 10 .0

Exsupnn il-eFno-rnrron or Pnoseru rn I In another test, the phosphate rock wasground'i Y in a mill charged with pebbles. The phosphate rock was separated into and +325 mesh sizes.

The +325; mesh phosphate rock was made into a pulp containing about solids and was conditioned with 2 pounds of mahogany sulfonates for one minute. I'wo pounds of sulphuric acid were added to and mixed with the conditioned pulp. Thereafter the pulp was diluted to about. 30% solids and floated in a mechanical flotation machineuntil flotation ceased.: The resultsof these tests are recorded ins'the following table:

' The grade or this concentrate with respect to I I Table phosphorus was 13.3%, The tailing from 'this I I I operation carried 45% of the phosphorus in the Product m: mt 13h feed and the-grade of the tailing was 4.5% phosn ohos. dlstrib.

-phorus. J I I When other acids were substituted for sulphuric l gg g 'af 13. I g? acid. and p n orpine oil was added before +325tail. 4113 Is I 11 notation, the comparative results shown in the 2 .iollowingtablewereobtained: Y I

Exempt: 8-Fr.orn'rrou or PHOSPHATE Rock I In another experiment, the phosphate rock was was further conditioned for one minute.

In the above tests with phosphate rock, the phosphate-bearing material was floated. This procedure is logical if the phosphate-bearing material or phosphate rock is relatively flneand the The phosphate rock obtained from Florida was,

formed into a pulp containing about 60% solids and conditioned with 1% pounds'of mahogany sulfonates for one minute. Aluminum sulfate, AI2(SO4)3.18H2O, in the amount of 0.8 pound was added to the conditioned pulp and the pulp The pulp was diluted to about 38% solids, 0.2 pound of pine oil was added and the pulp floated in a flotation machine until flotation ceased.

With this procedure, the froth contained 41.8% of the phosphorus in the feed and the grade of this material was 4.9% phosphorus. fIhe tailing from this same procedure contained 58.2% of the phosphorus, in the feed and the grade of this material was 11.1% hosphorus.

Additional experiments involving the use of metal salts such as ferrous sulfate, ferric sulfate, copper sulfate and manganous sulfate indicated that these salts tend also to activate and float quartz in preference to phosphate rock.

The above examples of the flotation of non metallic minerals show quite clearly that mahog-- an sulfonates are highly effective in the flotation of non-metallieminerals of widely varyin type. Inasmuch as the mahogany sulfonates. are inexpensive by-products, their use is commercially feasible in the flotation of these relatively low cost types of non-metallic mineral ores. Moreover, as shown in Example 6, the action of the maho any sulfonates in the presence of slimes Q is not adversely aifected inasmuch as all sizes of particles were floated together, a procedure not followed commercially. The usual procedure is to separate the coarse limestone from the slimes before the coarseparticles are floated. Therefore,v the mahogany sulfonates appear to fulflll all the requirements'for flotation operations on these types of materials.

. It; .will beunderstood that the proportions of flotation agents are susceptible to considerable variation in the treatment of the non-metallic mineral ores and, therefore, the proportions disclosed in the examples given above should be considered as illustrative 'of satisfactory concentrations and not as limiting the scope of the following claims.

' Iclaim: v

l. A froth flotation process comprising agitating and aerating an aqueous suspension of a non-metallic mineral ore in the presence of at leastone of the group of flotation agents consisting of oil-soluble,"water-dispersible and substantially water-insoluble mahogany sulfonates vand oil-soluble, water-dispersible and substantially water-insoluble petroleum sulfonic acids to coat andfloat a portion of said ore and form a tailing, and separating the tailing from the floated portion of the ore.

" 2. A froth flotation process comprising agitating least one of the group of flotation agents consisting of oil-soluble, water-'dispersible and substantially water-insoluble mahogany sulfonates and oil-soluble, water-dispersible' and substantially water-insoluble petroleum sulfonic acids to coat and float a portion of said ore and form a tailing, and separati'ngthe tailing from the floated portion of the ore.-

3. A froth flotation process comprising agitating and aerating an aqueous suspension of limestone in the presence of at least one of the group of flotation agents consisting of oil-soluble, waterdispersible and substantially water-insoluble mahogany sulfonates and oil-soluble, water-dispersible and, substantially water-insoluble petroleum sulfonic acids to coat and float a portion of said ore and form-a tailing, and separating the tailing from the floated portion of the ore. I

4. A froth flotation process comprising agitating and aerating an aqueous suspension of barite in the presence of at least one of the group of flotation agents consists of oil-soluble, water-dispersible' and substantially water-insoluble mahogany sulfonates and" oil-soluble, water-dis persible and substantially water-insoluble petroleumsulfonicacids to coat and float a portion of said ore and forma tailing, and separating the tailing from the floated portion of the ore.

5. A'froth flotation process comprising agitating and aerating an aqueous suspension of a nonmetallic mineral ore in the presence of a frother of the class consisting of pine oil and cresylic acid, and at least one of the group of flotation agents consisting of oil-soluble, water-dispersible and substantially water-insoluble mahogany sulfonates and oil-soluble, water-dispersible and substantially water-insoluble petroleum sulfonic acids to coat and float a portion of said ore and form a tailing, and separating the tailing from the floated portion of the ore.

6. A froth flotation process comprising agitating and aerating an aqueous suspension of a nonmetallic mineral ore in the presence of a strong acid and at least one of the group of flotation agents consisting of oil-soluble, water-dispersible and substantially water-insoluble mahogany sul-fl fonates and oil-soluble, water-dispersible and substantially water-insoluble petroleum sulfonic acids to coat and float a portion of said ore and metallic mineral ore inthe presence of a metal salt and at least one of the group of flotation agents consisting of oil-soluble, water-dispersible and substantially water-insoluble mahogany sulfonates and oil-soluble, water-dispersible and substantially water-insoluble petroleum sulfonic I acids to coat and float a portion of said ore and form a tailing, and separating the tailing from form a tailing, and separating the tailing from the floated portion of the ore.

9. A froth flotation process comprising agitating and aerating an aqueous suspension 'ofphosphate rock in the presence of a, strong acid and oil-soluble, water-dispersible and substantially water-insoluble mahogany sulfonates to concentrate the most valuable portion of the phosphate rock in the froth.

10. A froth flotation process comprising agitating and aerating an aqueous suspension of phosphate rock and containing coarse gangue in the presence of a strong acid and an oil-soluble, water-dispersible and substantially water-insoluble mahogany sulfonate to float a concentrate containing the most valuable portion of said phosphate rock 11. A froth flotation process comprising agitating and aerating an aqueous suspension of coarsely disintegrated phosphate rock containing gangue in the presence of a metallic salt and an oilsoluble, water-dispersible and substantially water-insoluble' mahogany sulfonate to float said gangue and depress said valuable portion of said phosphate rock to form a tailing.

tating and aerating an aqueous suspension of ground limestone containing gangue in the presence of fuel oil and an oil-soluble, water-dispersible and substantially water-insoluble mahogany sulfonate to float said limestone and cause said gangue to settle as tailing, 13. A froth flotation process comprising agitating and aerating an aqueous suspension of a calcium bearing ore in the presence of at least one of the group of collectors consisting of oilsoluble, water-dispersible and substantially water-insoluble mahogany sulfonates and oilsoluble, water-dispersible and substantially water-insoluble petroleum sulfonic acids, to coat and float a portion of said ore and form a tailing, and separating the tailing from the floated portion of the ore.

14. A froth flotation process comprising agitating and aerating an aqueous suspension of phosphate rock in the presence of fuel oil, a strong acid and oil-soluble, water-dispersible and substantially water-insoluble mahogany sulfonates to concentrate the most valuable portion of the phosphate rock in the froth.

WALTER E. KECK.

12. A froth flotation process comprising agi--