US3254762A

US3254762A - Conditioning of granular potash

Info

Publication number: US3254762A
Application number: US174108A
Authority: US
Inventors: Randal E Smith; Clarence W Egbom
Original assignee: Potash Corp of Saskatchewan Inc
Current assignee: Potash Corp of Saskatchewan Inc; Potash Company of America
Priority date: 1962-02-19
Filing date: 1962-02-19
Publication date: 1966-06-07
Anticipated expiration: 1983-06-07

Description

June 7, 1966 R. E. SMITH ETAL 3,254,762

CONDITIONING OF GRANULAR POTASH Filed Feb. 19, 1962 OIL 6 BRINE COARSE CLEANEDG DESLlMED f 8 7 CONCENTRATE ORE DRAINAGE FLOTATION l2 TAILINGS T0 BRINE CLARIFICATION BRINE 9 COARSE 7 CONCENTETE q 7 FLOTATION l2 TAILINGS T0 BRINE CLARIFICATION INVENTOR.

RANDAL E. SMITH CLARENCE W. EGBOM Attorneys of potash flotation.

United States Patent 3,254,762 CONDITIONING 0F GRANULAR POTASH Randal E. Smith and Clarence W. Egbom, Carlsbad, N. Mex., assignors to Potash Company of America, Carlsbad, N. Mex., a corporation of Colorado Filed Feb. 19, 1962, Ser. No. 174,108 17 Claims. (Cl. 209-2) This invention relates to the reagent conditioning of coarse sylvite ores and particularly to an improved method of conditioning such ores prior to flotation.

In the Carlsbad basin potash ores consisting principally of sylvinite, which is a mechanical mixture of sylvite and halite with clay and traces of other minerals, are generally upgraded by the flotation process. The flotation process 3,254,762 Patented June 7, 1966 v we economical and efficient preparation or conditioning of coarse potash ores for flotation treatment which provides a highly efficient flotation concentration of larger particles.

A further object of our invention is to provide a rapid and eflicient filming or coating of coarse potash ore particles without appreciable size reduction of particles by consists of grinding; sizing; scrubbing; desliming; dey watering, which includes removal of brine; conditioning with reagents; and flotation of the sylvite fraction by air bubble attachment.

Initial sizing is generally performed by dry screening into a coarse fraction of about -6 mesh and a standard fraction of minus 20 mesh (Tyler mesh size). The coarse and standard fractions are usually treated separately and this invention is directed primarily to the treatment of the coarse fraction.

The reagent conditioning of coarse sylvite ores is a I mixing operation in which amine and oil reagents are added to a pulp following scrubbing and slime removal operations. The amine reagent is well known in the art The preferred reagent for coarse flotation is in general based on octadecyl amine, but consists of mixtures prepared from natural fats with or without further hydrogenation. A common reagent is known as tallow amine, and the common reagent for coarse flotation is a hydrogenated tallow amine. This reagent is preferably added as an emulsion prepared by partial neutralization with acid.

The oils may be crude residues from petroleum refining and are generally heavy or viscous in character. Such viscous reagents are diflicult to distribute thoroughly in the slurry. It is recognized in the industry that gentle mixing for as short a time as possible is desirable in coarse sylvite conditioning, since increasing the time or intensity of the mixing or both may result in further slimes release or the production of fine particles by attrition, both of which consume additional reagent and have other undesirable effects. However, in many instances, gentle mixing in conventional fashion does not provide the thor ough reagent distribution necessary for effective flotation of coarse potash.

It has now been found that reagents can be added in the presence of considerable brine, provided the excess brine is removed before the pulp is fed to the flotation cell. We have found that the best results are attained when the reagents are added to a pulp containing about 15% or more brine by weight. Gentle mixing following brine removal has also been found to be effective in improving flotation efliciency,

Substantial improvements in flotation efliciency which may be observed as lower reagent rates or larger particles floated or both, are made possible by use of this method. It is particularly advantageous at low rates of reagent use.

It is an object of our invention to provide a'simple, economical and eflicient preparation or conditioning of potash ores for flotation treatment which provides a low rate of reagent use in highly eflicient flotation concentration.

Another object of this invention is to provide a simple,

attrition.

Still another object of this invention is to provide a simple, economical and efficient preparation or conditioning'of coarse potash ores which provides a highly eflicient flotation concentration without use of a clay blinding re agent in the treatment.

The practice of our invention will be described with ref erence to the accompanying drawings. In the drawings:

FIG. 1 is a typical flow sheet for the practiceof our invention utilizing a single reagent mixing stage; and

FIG. 2 is a typical flow sheet for the practice of our invention utilizing a two-stage mixing of reagent.

The flow'sheet of FIG. 1 depicts a typical practice where only a single stage mixing treatment is required. As shown, cleaned and deslimed ore from a suitable source of supply 3 is delivered into a mechanical mixer 4, preferably a horizontal rotary drum providing a retention time of from about 20 seconds to about 1 minute. An amine collector reagent 5 and an oil 6, if desired, are fed into mixer 4 in controlled quantities. A major portion of thebrine is removed from the ore, usually by gravity draining as on screen 7, and the separated brine may be returned to brine clarification.

The conditioned ore after brine removal is delivered as the feed 8 to a flotation stage 9 in which brine of the ore 10 is provided as the carrier vehicle in the flotation action. Coarse potash collects on the surface of the brine and is removed as a concentrate at 11, while the flotation tailings are removed as indicated at 12. Both concentrate and .tailings may be further processed as known in the art.

The circuit shown in FIG. 2 is essentially the same as the one just described, except for the two-stage mixing. After initially mixing at stage 4 and dewatering as indicated at 7, the ore is fed into a second mixer 4 also pro It is understood when referring to brine, we mean a solution prepared by contact with the ore, and which is approximately saturated with NaCl and KCl and which is used as the fluid medium in the sylvite ore dressing process.

Dewatering as used herein designates a liquid-solids separation-in which associated brine is separated from the ore.

In practicing the invention the coarse sylvite ore is prepared by crushing and screening the ore to obtain a particle size range that is substantially 6 +20 mesh. The ore is slurried in brine and scrubbed to release clay slimes. The pulp is then deslimed by washing with clean brine to remove all free slimes, leaving a clean pulp which is ready for reagent conditioning.

In our method, the clean pulp is delivered to the conditioner at a pulp density from 50% to solids, preferably about 65% solids. The conditioning vessel is preferably a revolving horizontal drum, turning at a rate to give gentle but thorough mixing. The amine reagent and the oil are added and the pulp is mixed for /2 to 1 minute, with the shorter time usually sufficient for complete reagent distribution. If the conditioner revolves too rapidly or if the retentiontime is too long, further slimes may be released causing a greater demand for reagents.

The presence of brine in this part of the conditioning formed on the carefully mixed lot of sylvinite ore from process is of value as a lubricant to further gentle the the Carlsbad, New Mexico basin. No auxiliary reagents mixing action and to distribute small quantities of reagents such as starch or guar were used. through the pulp. Table I contains typical examples of the effect of re- The pulp is then partially dewatered. This can be ac- 5 moving brine after initial mixing without further mixing.

TABLE I Reagent Rates, Percent 1st Mix Final Lb./Ton Temp., Tailings Percent Pulp Time, Drain Pulp F. Grade, Per- KC] Density Sec. Density cent K20 Recovery Amine Oil 65 60 No 65 0. 1 0. 6 77 11.01 64. e5 60 Yes 93 0. 1 0. 6 77 4. 28 87.6 75 60 No- 75 0. 06 0. 8 85 6. 77 76.3 75 60 Yes 95 0. 06 0. 8 85 3. 0a 89. 9 50 60 No 50 0. 06 0. 8 85 9. 00 66. 7 50 60 Yescomplished by draining by gravity through a screen or by 20 Table II illustrates the efiect of draining to different suction or other mechanical means. The pulp is drained pulp densities after initial mixing at uniform low pulp to 85% solids or above with the preferred density being densities.

TABLE II Reagent Rates, Percent 1st Mix Final Lb./Ton Temp, Tailings Percent Pulp Time, Drain Pulp F. Grade, Per- K01 Density Sec. Density cent K10 Recovery Amine Oil above 90%. This may take from 20 seconds to over 1 35 Table III illustrates the advantage gained in a typical minute by gravity depending on the depth of the ore bed, test in which a period of mixing was given the ore folreagent rates, particle size, etc. lowing draining of the brine used in the mixing step.

TABLE III Reagent Rates, Percent 1st 1st Mix 2nd Mix Final Pulp Lb./Ton Temp., 'lailings Percent KCl Pulp Density Time, Sec. Drain Time, See. Density F. Grade, Per- Recovery cent K10 Amine Oil 65 Yes 93 0. 1 0. 6 77 4. 28 87. 6 30 Yes 30 93 0. 1 0. 6 77 2.88 91. 9

As the brine is drained from the pulp the solids may 50 Table IV contains a number of general examples showbe mixed gently. Flotation of the prepared ore provides ing the advantage of draining after initial mixing over improved recovery over that at identical reagent rates not draining at various levels of reagent use, different without draining, or, comparble flotation is achieved at starting pulp densities and at two different temperatures.

TABLE IV Reagent Rates, Percent 1st 1st Mix 2nd Mix Final Pulp Lb./T0n Temp, Tailings Percent KC] Pulp Density Time, Sec. Drain Time, See. Density F. Grade, Per- Recovery cent K20 Amine Oil substantially reduced reagent rates when the reagentized Table V illustrates the combined effect of initial mixore is dewatered. ing at low pulp density, followed by draining and further To illustrate the advantages of the invention, the followmixing over conventional conditioning. Results are ing flotation results are tabulated. All tests were per- 75 shown at two different reagent rates.

TABLE v Reagent Rates, Percent 1st 1st Mix 2nd Mix- Final Pulp LbJTon Temp., Taillngs Percent K01 Pulp Density Time, Sec. Drain Time, Sec. Density F. Grade, Per- Recovery cent K20 Amine Oil 95 60 N o 95 0. 1 0. 8 90 7. 18 76. 74 30 Yes 3O 93 0. 1 0.8 90 4. 22 86. 2 95 60 No 95 0. 2 0.8 90 2. 91 90. 7 74 30 Yes 30 93 v 0. 2 0.8 90 2. 64 91. 5

We have thus found a distinct improvement in conditioning of these ores by distributing the reagent in a wet pulp, followed by draining oflthe excess brine.

Since these factors will vary with reagent rates, with temperature, with type of reagent, the times suggested are for explanation only, and we do not intend to be limited by them. Changes and modifications may be availed of within the spirit and scope of the invention as defined in the hereunto appended claims.

What We claim is:

1. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and desilimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85 solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal without further treatment into a flotation concentration stage.

2. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced without material attrition, then removing the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85% solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal without further treatment into a flotation concentration stage.

3. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a.

pulp density of about 50% to 85% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced for from about 20 seconds to about one minute, then'moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85 solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal Without further treatment into a flotation concentration stage.

4. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and desilimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of more than 85% solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal without further treatment into a flotation concentration stage.

and reagent so introduced for about one minute, then moving the pulp and reagent mixture directly into a brine re moval stage in which a portion of the brine is removed to establish a pulp density of at least solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal without further treatment into .a flotation concentration stage.

6. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine drainage stage in which a portion of the brine is removed to establish a pulp density of at least 85% solids and wherein reagentized ore surfaces areexposed to atmosphere, and passing the reagentized ore after brine removal without further treatment into a flotation concentration stage.

7. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% 'to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of about solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized are after brine removal without further treatment into a flotation concentration stage.

' 8. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85 solids, introducing an amine collector reagent into said 'pulp, mixing the pulp and reagent so introduced without blinding reagent addition, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85 solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal without repulping into a flotation concentration stage.

9. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50%to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85% solids and wherein reagentized ore surfaces are exposed to atmosphere, and

7 passing the reagentized ore after brine removal and a said established density into a flotation concentration sage.

10. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and -a brine carrier and having a pulp density of about 50% to 85% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85% solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after final mixing without further treatment into -a flotation concentration stage.

11. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced without blinding reagent addition, then moving the pulp and reagent mixture directly into a brine removal stage in which a .portion of the brine is removed to establish a pulp density of at least 85% solids and wherin reagentized ore surfaces are exposed to atmosphere, subjecting the ore and said reagent to additional mixing after brine removal, and passing the reagentized ore after final mixing directly into a flotation concentration stage.

12. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced for from about 20 seconds to about one minute, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 85% solids and wherein reagentized ore surfaces are exposed to atmosphere, mixing the ore at said density with said reagent for from 20 seconds to about one minute, and passing the reagentized ore after final mixing without further treatment into a flotation concentration stage.

13. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least 90% solids and wherein reagentized ore surfaces are exposed to atmosphere, subjecting the ore and said reagent to additional mixing after brine removal, and passing the reagentized ore after final mixing without further treatment into a flotation concentration stage.

14. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine removal stage in which a portion of the brine is removed to establish a pulp density of at least solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine removal without further treatment into a flotation concentration stage.

15. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 65% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced, then moving the pulp and reagent mixture directly into a brine drainage stage in which a portion of the brine is removed to establish a pulp density of at least solids and wherein reagentized ore surfaces are exposed to atmosphere, and passing the reagentized ore after brine drainage without further treatment into a flotation concentration stage.

16. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85% solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced at a first mixing stage, then moving the pulp and reagent mixture directly into a brine removal stage in which sufiicient free brine is removed to establish a pulp density of at least 85 solids and wherein reagentized ore surfaces are exposed to atmosphere, moving the reagentized ore after brine removal through a second mixing stage, and passing the reagentized ore after final mixing and at said established density into a flotation concentration stage.

17. A method of preparing potash ores for a flotation treatment, consisting of the steps of forming a pulp of cleaned and deslimed potash ore in a size range of about minus 6 plus 20 mesh and a brine carrier and having a pulp density of about 50% to 85 solids, introducing an amine collector reagent into said pulp, mixing the pulp and reagent so introduced at a first mixing stage, then moving the pulp and reagent mixture directly into a brine-removal stage in which suificient free brine is removed to establish a pulp density of at least 85% solids and wherein reagentized ore surfaces are exposed to atmosphere, moving the reagentized ore after brine removal through a second mixing stage for mixing with said reagent for from about 20 seconds to one minute, and passing the reagentized ore after final mixing and at said established density into a flotation concentration stage.

References Cited by the Examiner UNITED STATES PATENTS 2,950,007 8/1960 Smith 209-116 FRANK W. LUTTER, Primary Examiner.

ROBERT A. OLEARY, Examiner.

Claims

1. A METHOD OF PREPARING POTASH ORES FOR A FLOTATION TREATMENT, CONSISTING OF THE STEPS OF FORMING A PULP OF CLEANED AND DESILIMED POTASH ORE IN A SIZE RANGE OF ABOUT MINUS 6 PINS 20 MESH AND A BRINE CARRIER AND HAVING A PULP DENSITY OF ABOUT 50% TO 80% SOLIDS, INTRODUCING AN AMINE COLLECTOR REAGENT INTO SAID PULP, MIXING THE PULP AND REAGENT TO INTRODUCED, THEN MOVING THE PULP AND REAGENT MIXTURE DIRECTLY INTO A BRINE REMOVAL STAGE IN WHICH