AU598733B2 - A process for agglomerating mineral ore concentrate utilizing emulsions of polymer binders or dry polymer binders - Google Patents

Description

~ji~ 70WP/00/ 011 598733

I

Form PATENTS ACT 1952-1973 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Class: Int. Cl: Application Number: 5- 7 y 9 6.

Lodged: "'Complete Specification-Lodged: 0 Accepted: P::riority: Pbihd 00o 0 ~ThkdO umTelt contdils tile anierndIleilts nmade Wnder S-cctiofl 49 and is correct for prin Li ter Related Art: a040 :0 40 Name of Applicant: 0 A: Address of Applicant: Actual Inventor: TO BE COMPLETED BY APPLICANT UNION CARBIDE CORPORATION, a corporation organised and existing under the laws of the State of Connecticut', Iocated at Old Ridgebury Road, Danbury, State of Cor',necticut, 06817, United States of Americak.

MEYER ROBERT ROSEN and LAWRENCE MARLIN Address for Service: Care of: JAMES M. LAWRIE CO., Patenit Attorneys of 72 Willsmere Road, Kew, 3101, Victoria, Australia.

Complete Specification for the invention entitled: A PROCESS FOR AGGLOMERATING MINERAL ORE CONCENTRATE UTILIZING EMULSIONS OF POLYMER BINDERS OR DRY POLYMER BINDERS Th16 following statement is a full descrip!,lon of this invention, including the best method of performing It known tome: 'Note: The description Is to be typed In double spacing, pica type face. In an area not exceeding 250 mm In depth and 160 mm In width, on tough white paper of good quality and It Is to be Inscrted Inside this form.

11710/76- L ,TIroNCmrowithovrmr rnera.,ri 11 I

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SA PROCESS FOR AGGLOMERATING MINERAL ORE CONCENTRATE UTILIZING EMULSIONS OF POLYMER)BINDERS OR DRY POLYMER BINDERS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to methods for agglomerating or pelletizing mineral ore concentrate.

More specifically, this invention relates to methods for agglomerating or pelletizing mineral ore concentrate Susing water soluble, high molecular weight polymer binder systems in either water-in-oil emulsions or as a

SSI

S4 dry powder.

46 o S l t *6 4 2. Description of the Prior Art ,shipping of the ore. Mineral ore concentrates can include iron oxides, copper oxides, barytes, lead and zinc sulfides, and nickel sulfides. Agglomerates of

I

coal dust and nonmetalic minerals used to make bricks or 4, agglomerate or pelletize inely ground mineral ore 4 o concentrate o as to further facilitomerate formsthe handing and pellets, briquettes, and sinters.

Methshipping of the ore. M ineral ore concen trates cante a freq coal dust and in mining operationls used to make bricks or low gceramics are also formed. Agglomerate forms can ores arinclude pellets, briquettes, and sinters.

Methods of pelletizing mineral ore concentrate are frequently used in mining operations where the ore is a low grade iron ore. Examples of low grade iron ores are I S D- 14, 8314 ta a.

4 a 4a a ~a~a a.

a p a .4 a.

,qa a a.

a. a a a..

15 a aq a, aa *a a a a #44 a 4 a,.

20 a 44 taconite, hematite, and magnet.ite. Numerous other low grade ores exist wherein pelletizing of the ground particles is beneficial to the handling and shipment of the mineral ore. After the mineral ore has been mined, it is frequently ground and screened to remove large particles which are recycled for further grinding.

Typically, an ore is passed through a 100 mesh (0.1 1 49mn) screen. The screened mineral ore is known as a "concentrate".

For example, taconite mineral ore concentrate after grinding and screening has an avierage moisture content of between about 6 to about 10 percent. The moisture content of the mineral ore concentrate can be selectively altered. The moisture content affects the strength of the pellets that are formed l~ater in the pr'ocess.

After screening, the mineral ore concentrate is k.-1Ih4. cfC transported on a first conveyor means to a blling du~ or another means for pelletizing mineral ore concentrate. Prior to entering the balling -idiatm, 1 a binding agent is applied or mixed into the mineral ore concentrate. Commingling the binding agent with the mineral ore concentrate occurs both on the conveyor means and in the means for pelletizing. The binding agents hold the mineral ore concentrate together as D-14,834 pellets until after firing.

Balling dr'ums are apparatus. comprising long cylindrical drums which are inclined and rotated. The mineral ore concentrate is simultaneously rotated about the balling drum's circumference and rolled in a downward direction through the drum. In this manner the mineral ore concentr,.Ate is rolled and tumbled together to form roughly spherical-shaped pellets. As the pellets grow in size and weight they travel down the Incline of the drum and pass through the exit of the *to drum at which point they are dropped onto a second 0 4* 6 o 4conveyor means which transports them to a kiln for firing. Inside the balling drum, different factors Ainfluence the mechanisms of union of the mineral ore concentrate. These factors include the moisture content of the ore, the shape and _eam=S- size of the rtineral *ARQ ore particles, and the distribution of conoentrate particles by size. Other properties of the mineral ore concentrate that influence the pelletizing operation 20 include the mineral ore's wettability and chemical charatteristics. The characteristics of the equipment used, such as its size and speed of rotation, can effect the efficiency of the pelletizing operation. The nature and quantity of the agglomerating or binding agent used in the concentirate is also a factor~ that determines part 9 A D-14,834 of the efficiency of the pelletizing operation.

The formation of agglomerates begins with the interfacial forces which have a cohesive effect between particles of mineral ore concentrate. These include capillary forces developed in liquid ridges between the particle surfaces. Numerous particles adhere to one another and form small pellets. The continued rolling of the small pellets within the balling' dmi causes more t" particles to come into contact with one another and

C

S 10 adhere to each other by the capillary tension and 4 compressive stress. These forces cause the union of 4 particles in small pellets to grow in much the same manner as a snowball grows as it is rolled.

o After the balling=-dma operation, the pellets are 15 formed, but they are still wet. These pellets are commonly known as "green pellets" though taconite

C

Spellets, for example, are usually black in color. Green pellets usually have a density of about 130 lb/ft 3 in sizes betieen about 1/2 inch and about 3/8 of an inch.

The green pellets are transported to a kiln and heated in stages to an end temperature of approximately 2800°F.

After heating, fired pellets are extremely hard and resist cracking upon being dropped and resist crushing when compressed.

Two standard tests are used to measure the strength random sampling of pellets a distance, usually about 18 5 inches or less n tom: :ntti th- e i P 1 9 "crack. The number of drops to crack each pellet is 1 recorded and averaged. Compression strength is measured by compressing or applying pressure to a random sampling D-l14,834 11S of pellets whether the pellets arumble. The pellets or 0 force required to crush the pellets is recorded and fiaveraged ts. Thesew tests are th e drop test and the strength of both wet and fired pellets. The drop and compression" test m easurements are important becausees dropping a pelletrandom samploceeding through the busuall about 18 inches or less 4 hp t:m- p until h h crack. The number of drops to crack each pellet is subsequent converaged. Compression strength is measured wellby compressing or applying pressurom the weightt o a rando sampling of pellets until the pellets crumble. The pounds of Thermal shook resistance is a factor which must be taken into consideration in any plocess for 20 agglomerating mineral ore concentrate. Increases in a pell0 for ce required to crush the pellets impov e that pellet's ability t. These t ino testsrnal pre used o measured by the struengthevap of both et ated fired pellets. T he drop and compressive test measurements are important because a kiln. If the pellet has numerous poresproceeding through whichthe balling dum and 5 ubsequent conveyor beltscape thermal shock requent drops as well as compressive forces from the weight of other *I4 pelletpon top of them.

Thermal shok resistance is a factor which must be 1 *^taken into consideration in any process for *-20 agglomerating mineral ore concentratfe. Increaes in a pellet's thermal shock resistance improye that pellet's ability to resist internal pressures created by the 1 sudden evaporation of Water when the pellet is heated in a kiln. If the pellet has numerous pores through which the water vapor carl escape thermal shock resistance is r Y ~i i r r

I

D-14,834 0 09 401 9*O rt 99 *4 9*4 9 4 0 20 9 44 4r improved. If the surface of the pellet is smooth and continuous without pores the pellet has an increased tendency to shatter upon rapid heating. This causes a concurrent increase in the amount of "fines" or coarse particles in the pelletized mineral ore. A binder which increases the pores formed in a pellet improves that pellet's ability to resist thermal shock.

Bentonite is used as a binding agent in the pelletizing operations for taconite ore concentrate.

Bentonite produces a high strength pellet having an acceptable drop strength, compressive strength, and thermal shock resistance. Bentonite ha s the disadvantage of increasing the silica content of the pellets that are formed. SilIca decreases the efficiency of blast furnace operations used in smelting of the ore. For this reason bentonite requires a higher energy expenditure than do organic binders.

-AbC Binding agents have proven to be betterX binders.t'-n h n'n;at- These agents include organic binders such as poly(acrylamide), polymethacrylamide, carboxymethylcellulose, hydrcxyethylcellulose, carboxyhydroxyethylcellulose, poly(ethylene oxide), guar gum, and others. The use of organic binders in mineral ore pelletizing operations is desirable over the use of bentonite because organic binders do not increase the D-14,834 7 silica content of pellets and they improve the thermal shock resistance of the pellets. Organic binders burny during pellet firing operations and cause an increase in the porosity of the pellets. Firing conditions can be modified to improve fired pellets' mechanical properties for organic binder systems.

Some organic binders used in mineral ore pelletizing operations are dissolved in an aqueous eo solution which is sprayed onto the mineral ore concentrate prior to entering the balling. A +ms This application of an aqueous solution increases the o moisture content above the natural or inherent moisture content of the mineral ore concentrate, which requires a S greater energy expenditure during the firing operation of the pellets. This increased moisture content also causes an increased likelihood of shattering due to Sinadequate thermal shock resistance during firing.

Pellet formation is improved with the use of organic binders, but the drop strength and compression strength 2' 0 of the pellet are frequently below that desired or achieved with bentonite.

Other binders commonly used for agglomerating mineral ore concentrate include a mixture of bentonite, clay and a soap, Portland cement, sodium silicate, and a mixture of an alkali salt of carboxymethylcellulose and r'e D-14,834 0 Otto 0 t4 10 4 0 0 O 4 0 15 00« 0 0 0 40 0 t 0 an alkali metal salt. The agglomerates made from these binding agents frequently encounter the problems described above of insufficient pellet strength or insufficient porosity for the rapid release of steam during induration with heat. Additionally, these binding agents are usually applied to a mineral ore concentrate in aqueous carrier solutions or as dry powders. Aqueous carrier solutions increase the amount of energy required to fire the pellets anG increases the incidence of pellet shattering due to inadequate thermal shock resistance.

U.S. Patent Number 3,893,847 to Derrick discloses a binder and method for agglomerating mineral ore concentrate. The binder used is a high molecular weight, substantially straight chain water soluble polymer. This polymer is used in an aqueous solution.

The polymers disclosed as useful with th Derrick invention include copolymers of acrylamide as well as other polymers. The Derrick invention claims the use of polymers in an "aqueous" solution. The use of water as a carrier solution for the binding agents increases the moisture of the agglomerates or pellets that are formed° The higher moisture content increases the energy required to fire the pellets and can increase the rate of destruction of the pellets during induration due to i ^Mn r D-14,834 9 the rapid release of ste.am through the agglomerate.

The industry is lacking a method for agglomerating mineral ore concentrate utilizing low water content non-bentonite binder systems, such as water soluble, high molecular weight polymer binder systems in water-in-oil emulsions or dry powders. This invention provides pellets formed from the mineral ore concentrate of high mechanical strength properties.

4* SUMMARY OF THE INVENTION 10 This invention is a method for agglomerating d to particulate material such as a mineral ore concentrate comprising the commingling of mineral ore concentrate with a binding amount of water soluble, high molecular o, weight polymers. The polymers are adapted to be selectively usable in at least one of either of two Sconditions of use. In a first condition of use the polymers are applied to the mineral ore concentrate as a i t dry powder. In a second condition of use the polymers are applied to the mineral ore concentrate in a water-in-oil emulsion.

This invention also includes/a method comprising the commingling of dry poly(acrylamide) hased polymer onto mineral ore concentrate wherein the inherent or added moisture content of the mineral ore concentrate is -1 D-14l,834 sufficient to activate the poly(acrylamide) based polymer to form pellets o f the mit' ,al ore.

This invention Is particularly desirable when used with an iron ore concentrate and can also include the application of an inorganic salt such as sodium carbonate, calcium carbonate, sodium chloride, sodium metaphosphate and mixtures of these in conjunction with the polymer. The inorganic salt can be applied as a powder or an aqueous solution.

DETAILED DESCRIPTION OF THE INVENTION This invention is a method for agglomerating particulate material such as a mineral orq conicantrate using water soluble, high molecular weight polymers in 22 an amount sufficient to bind the mineral ore concentrate. The polymers are applied to the particulate material in at least one of either a water-in-oil emulsion system or a dry powder system.

The application of the polyiaers to a mineral ore concentrate can be in conjunction with an inorganic Salt or mixtures of inorganic salts applied as powders or in aqueous solutions. The polymers and inorganic salts are commingled with the mineral ore concentrate.

This composition then enters a standard means for pelletizing4 a balling drum. The means for 1 t

D-

1 4,834 11 pelletizing further commingles the ingredients and forms wet or "green" pellets. The pellets are then transferred or conveyed to a furnace or kiln where they are indurated by heat at temperatures above about 1800 0

F

and more preferably at about 2800 0 F. After induration, the pellets are ready for shipping or further processing in a smelting operation such as a blast furrace.

Suitable polymers useful in this invention include water soluble homopolymers, copolymers, terpolymers, and S. *10 tetrapolymers. In a water-in-oil emulsion system the *6 selected polymer is produced by polymerizing its *monomeric water-in-oil emulsion precursor. Suitable polymers can be anionic, cationic, amphoteric, or nonionic. It is desirable in this invention to use 15 polymers of high molecular weight as characterized by a high intrinsic viscosity. This inventlon is not limited U to polymers of high intrinsic viscoaity.

Polymers suitable fo use with this invantion, whether used in water-in-oil emulsion systems or %n dry 120 powder systems, are particularly desirable when they are of a high molecular weight. The particular molecular weight of a polymer is not limiting upon this invention.

Suitable polymers include synthetic vinyl polymer) and other polymers as distinguished from defiftvves of natural cellulosic produats sudh a I -14,834 12 carboxymethylcellulose, hydroxyethylcellulose, and other cellulose derivatives.

Useful measurements of a polymer's average molecular weight are determined by either the polymer's intrinsic viscosity or reduced viscosity. In general, polymers of high intrinsic viscosity or high reduced viscosity have a high molecular weight. An intrinsic viscosity is a more accurate determination of a polymer's average molecular weight than is a reduced j 0*,'10 viscosity measurement. A polymer's ability to form I 'pellets of mineral ore concentrate is increased as the polymer's intrinsic viscosity or reduced viscosity is increased. The most desirable polymers used in the process of this invention have an intrinsic viscosity of "o 15 from about 0.5 to about 40, preferably from about 2 to t about 35 and most preferably from about 4 to about I t dl/g as measured in a one normal aqueous sodium chloride solution at 2500.

i. Water soluble polymers include, among others, i20 poly(acrylamide) based polymers and those polymers which polymerize upon addition of vinyl or acrylic monomers in .,solution with a free radical. Typically, such polymers -1 I- 17: I 1 D-14,834 13 have ionic functional groups such as carboxyl, sulfamide, or quaternary ammonium groups. Suitable polymers can be derived from ethylenically unsaturated monomers including acrylamide, acrylic acid, and methylacrylamide. Alkali metal or ammonium salts of these polymers can also be useful.

Desirable polymers for use in this invention are preferably of the following general formula: .r 44 S« NH 0 2 *s-IbC

NH

2 0 A A R

J

d D14 834I 14 wherein R, R 1 and R 3 are independently hydrogen or 0-I~~ methyl, R i~s an alkali metal ion, such as Na) ,o r Ta- R4Is either -OR 5 wherein R 5 is an alkyl group having up to 5 carbon atomns; (2) C-0- R 6 wherein Ft is an alkyl group having up to 8 fi :2carbon atomis; -0 -C -R wherein R7 is either methyl Or ethyl; substituted pheniyl; -ON; or N" ;and wherein is from 0 to about 90, preferably from about 30 to about 60 percent, is from 0 to about 90, preferably from 4ra about 30 to about 60 percent, is from about 0 to about 4 (4 with the proviso thapt equal 100 oercent, and (d) is an integer of from about 1,000 to about 500,000.

a a.

a j( t 15 D-14, 8314 16 Under certain conditions, the alkoxy or acyloxy groups In the polymer can be partially hydrolyzed to the corresponding alcohol group and yield a tetrapolymer of the following general formula: 1R3 3

-CH

2 C H2-C -CH C- U=0 0=0 R U1H .4,4 9 e

NH

R

6 tI k 17 D-14I,834 iherein R, R 1

R

2 H 3 a, b, and d are as previously (defined, R4 is -OR 5 or 0 -0-C-H wherein H and R7 are as defined previously, c is from about 0.2 to about percent, and e is from about 0.1 to less than about percent.

The preferred copolymers are of the following formula: 9 *4 o CH2 c oo,

I

so. NH2 jd I UU9 '4 D-14I, 834 o wherein R is an alkali metal ion, such as Naor=K+ 4 and f' is from 5 to about 90, preferably from about 30 to about 60 percent, g is from 5 to about 90, preferably from about 30 to about 60 percent with the proviso that equal 100 percent, and Is an integer of from about 1,000 to about 500,000.

The preferred terpolymers are of the following formula: ti 44 t *444 4* 4 4 4! 4 4 .44 t *4 4 4~44 4 *4 4 .44 44 4! t 44 4.! 4 4* 4 4 4- *4 *4 4 4 4*4 4 "4 4 4444 4, 4 4 4 4 4*

H

C =0 N1 H H I I 0 0=0 R7 1 D-14I,834 19 wherein R +is Na, R 7 is methyl, ethyl, or butyl and f is from about 5 to about 90, 4referably from about to about 60 percent, g is from about 5 to preferably from about 30 to 60 percent, h is from about 0.2 to about 20, with th~e proviso that equal 100 percent and d is as previously defined.

The preferred tetrapolymers are of the following formula: 9*99 9 999 9 09 9 9 99 9 ~9 0 9 999 9 99 99 990 9 *9 99 9 999 9 0=0

NH

2 -CHz.0} -C H4Jg 99 9 9 9999 9 99 99 9 99 9 99 99 9 10 wherein Rl, R 2 R 3 RT, f, g, h, d, and e are as previou~ly defined.

.999 9 9 9999 99 9 9 99 9 99

:I

D-14, 834 Other desirable water soluble polymers for use with this invention include those derived from homopolymerization and interpolymerization of one or more of the following water soluble monomers: acrylic and methacrylic acid; acrylic and methacrylic acid salts of the formula 0

II

C 0 CH 2 R Ooeo 0 0 f t: too sc o 2o O 00 te 0 00 15 2 a r rr r s wherein R 8 is a hydrogen atom or a methyl group and R 9 is a hydrogen atom, an alkali metal atom sodium, potassium), an ammonium group, an organoammonium group of the formula (R 10

)(R

11

)(R

12 NH+ (where R 1 0

R

11 and R12 are independently selected from a hydrogen atom, and an alkyl group having from 1 to 18 carbon atoms (it may be necessary to control the number and length of long-chain alkyl groups to assure that the monomer is water soluble), such as 1 to 3 carbon atoms, an aryl group, such as a benzyl group, or a hydroxyalkyl group having from 1 to 3 carbon atoms, such as triethanolamine, or mixtures thereof); acrylamide and methacrylamide and derivatives including acrylamido- and methacrylamido monomers of the formula: D-141,834 21 R 13 0 R1 155 ety u;wherein R is a hydrogen atom a methyl op group, an ethyl group or -R SOX wherein R is a divalent hydrocarbon group alkylene, phenylene, or cycloalkylene having from 1 to 13 carbon atoms, preferably an alkylene group having from 2 to 8 carbon ';:'atoms, a cycloalkylene group having from 6 to 8 carbon 4 0 atoms, or phenylene, most preferably -C(011 3

)-CH

2 -CH CH 2 "-OH(CH )-CH 2 and CH3 SX is a monovalent cation such as a hydrogen atom, an alkali metal atom sodium or potassium), an ammonium group, an organoammonium group of the formula (R 1 7 (R 1 8 (Rl 9 NH+ wherein R 17 R 18 S R 9 are Independently selected from a hydrogen atom, an alkyl 1. group having from 1 to 18 carbon atoms (it may be necessary to control the number and length of long-chain alkyl groups to assure that the monomer is water soluble) such as 1 to 3 carbon atoms, an aryl group such as a phenyl or benzyl group, or a hydroxyalkyl group having from 1 to 3 carbon atoms such as triethanolamine, or mixtures thereof, and the like. Specific examples of water-soluble monomers which can be homopolymerized or interpolymerized and useful in the process of this ,r*c 10 invention are acrylamido- and methacrylamido- sulfonic C 14 SI, acids and sulfonates such as 2-acrylamido-2- S" methylpropanesulfonic acid (available from the Lubrizol Corporation under its tradename, and hereinafter referred to as, AMPS), sodium AMPS, ammonium AMPS, organoammonium AMPS. These polymers can be effective binding agents for mineral ore concentrates in about the same concentrations or binding amounts used for the o-neas polyacrylamide based polymer bilders.

These water soluble monomers can be 20 interpolymerized with a minor amount less than *tot about 20 mole percent, preferably less than about mole percent, based on the total monomers fed to the reaction) of one or more hydrophobic vinyl monomers.

For example, vinyl monomers of the formula D-14,834

R

CH2 C R21 wherein R 20 is a hydrogen atom or a methy) group 0

II

and R21 is 0 C R 2 2 a halogen atom chlorine), -0-R 2 3 2 4 or -C-OR 2 wherein

R

25 is an alkyl group, an aryl group or an aralkyl group 5 having fPom 1 to 18 carbon atoms, wherein R2 2 is an alkyl group having from 1 to 8 carbon atoms, R23 is an S- alkyl group having from 1 to 6 carbon atoms, preferably 2-4 carbon atoms, R 24 is a hydrogen atom, a methyl group, an ethyl group, or a halogen atom 10 chlorine), preferably a hydrogen atom or a methyl group, with the proviso that R 20 is preferably a hydrogen atom S* when R is an alkyl group. Specific examples of suitable copolymerizable hydrophobic vinyl monomers are 4,4, alkyl esters of acrylic and methacrylic acids such as «15 methyl acrylate, methyl methacrylate, ethyl acrylate,

WI

ethyl methacrylate, butyl acrylate, isobutyl acrylate, S' dodecyl acrylate, 2-ethylhexyl acrylate, etc.; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, etc.; vinylbenzenes such as styrene, alpha-methyl styrene, vinyl toluene; vinyl ethers such D-14,834 24 as propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, methyl vinyl ether, ethyl vinyl ether, etc.; vinyl halides such as vinyl chloride, vinylidene chloride, etc.; and the like.

The preferred water soluble monomers of these water soluble polymers are acrylamide, AMPS and sodium AMPS, sodium acrylate, and ammonium acrylate. The preferred hydrophobic monomers are vinyl acetate, ethyl acrylate, styrene and methyl methacrylate.

t t I t jt E fI 2D-14,834 Examples of suitable polymers for use with this invention in water-in-oil emulsions)are listed in Table I. This table provides a representative listing of suitable polymers for use in the water-in-oil emulsions, but does not encompass every suitable polymer or limit the polymers that can be used with this invention.

iisl

L

4gt

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i- i D-14, 834 TABLE I Polyacrylarnide) Emulsions 1 Mole Anionic Copolymers PAM/Na Acrylate Intrinsic ViscositY_ Solids 85/15 76/24 59/41 16.2 17.3 20.0 Cationic Copolymers PAM/Sipomer Q5-80 2 94/16 PAM/N-decyl Acrylamide 44U4 4 4 4 rt *4 4 *44 4 4'o 4r 4 *41 Q* 44 44 4 .44 q 4 *1

T

4 4L 4<44r 4444 f '4 Nonionic Copolymer~s 99/1 5.8 Anionic Terpolyners PAM/NaA/Vinyl Acetate 7 1/24/5 80/15/5 PAM/NaAMPSVinyl Acetate 87/1,2/1 10.8 23.0 20 0 RV =17.5 29.5 10.0 1 abbreviations; PAM: poly(acrylamide); NaA: sodium acrylate; NaANPS: sodium salt of 2-acrylamido-2-methylpropanesulfonic acid.

2 Sipomer Q5-80 is a cationic compound of dimethylaminoethylmetharylate/dimethy l sulfate qurternary salt.

3 Reduced Viscosity.

>4d D-14,834 27 i A second class of polymer's includes those polymers used with this invention in dry powder form. These polymers must be water soluble, but do not necessarily lend themselves to the formation of water-in-oil emulsions. Typically, polymers which form water-in-oil emulsions are also useful with the invented method as dry powder. Table II represents a listing of polymers which are desirable for use with this invention as powders. The powders listed in Table II do not o e 10 encompass all polymers which can be used as powders in t this invention.

9* e a I (I ::6t -7 D-14I, 8314 TABLE II Poly(acrylamide) Powders Nonionic Rhone Poulenc

AD-

1 (intrinsic viscosity 15.l4dl/g) Anionic Approx'imate mole PAM/NaA 89/11 77/23 Percol: 725 2 Percol 726 0000 0 0000 0 ~0 00 0 0 00 00 00 0 000 0 0~ 00 000 O 99 00 0 000 0 1AD-10 is a poly(acrylamide) powder sold by Rhone Poulenc, 52 Vanderbilt Avenue, New York, NY.

2 Percol products have been analyzed to be copolymers containing the approximate mole of PAM and NaA given in Table II and are sold by Allied Colloids of Fairfield, New Jersey.

0 00 0 0004 0 09 00 4 00 I. 49 III 4 #144 4 I ItO 00 4 I it 14 Inorganic salts are optionally added to the mineral ore concentrate before balling operations primarily to increase the strength of the wet (green drop strength) or dry pellets (dry crush strength)pellets. Inorganic salts can be added either before, after, or during the addition of the dry or emulsified polymer.

Polymers alone improve the dry compression strength of pellets, but not to the same degree as an inorganic salt. For this reason, desirable embodiments of this invention include the addition of an inorganic salt, however, this addition is not considered limiting upon this invention. Similarly, neither the inorganic: salt selected nor the method of addition is limiting upon this invention. For purposes of this invention the term "polymer binder system" can include a water soluble, high molecular weight polymer in either a water-in-oil emulsion system or a powder system regardless of whether the system includes, or is used with or without inorganic salt powders or solutions.

Inorganic salts suitable for use in this invention include alkali and alkali metal salts or carbonates, halides, or phosphates. Specific examples of inorganic salts include sodium carbonate (Na 2

CO

3 calcium carbonate (CaCO 3 which may also be referred to in this specification as limestone), sodium metaphosphate (NaPO 3 where n is 2 or more, sodium chloride (NaCl),,and mixtures of these. Other inorganic salts can be added to improve pellet 20 compression strength. Additionally, inorganic S29a S29a

PVT

D-14,834 salts can be added in mixtures with one another as powders oi- in solutions. As the concentration of inorganic salt increases in the mineral ore concentrate, the acrgmec**e n strength of the resulting pellets is increased.

Sodium carbonate is an inorganic salt that achieves good results for improving the compression strength of pellets. Sodium carbonate is most effective, when used with either the dry or emulsified polymer, in an amount of at least 2 percent and preferably greater than percent, calculated on the total weight of the added *4 Sinorganic salt and active polymer. Preferably the concentration of sodium carbonate as a percent of the weight of the polymer binder system varies from about percent to about 95 percent. More preferably, sodium carbonate is within the range of about 30 percent to E, about 90 percent with the most optimum range between about 50 percent to about 90 percent calculated on the total weight of the mixture of sodium carbonate and the polymer.

The invertible water-in-oil emulsion system used in Sthis invention is a suspension of droplets comprised of "i both water soluble, high molecular weight polymers and water in a hydrophobic substance. Examples of suitable emulsion systems and methods to form suitable emulsions A, D-14,834 31 are found in U.S. Patent Number 4,485,209 to Fan et al.

and U.S. Patent Number 4,452,940 to Rosen et al. each of which are herein incorporated by reference.

Desirable hydrophobic liquids used in these emulsion systems are isoparaffinic hydrocarbons. A suitable isoparaffinic hydrocarbon is that sold by the Exxon Corporation known as Isopar M. Other suitable hydrophobic liquids for use as the external phase in an emulsion system include benzene, xylene, toluene, mineral oils, kerosenes, petroleum, paraffinic 21rr t hydrocarbons, and mixtures of these.

S, In desirable embodiments of this invention, which include a polymer binding agent in a I t water-in-oil emulsion, two surfactants are used to form the emulsion. A first surfactant is used to form the water-in-oil emulsion system. After the water-in-oil ,r emulsion system is formed, a second surfactant is added.

t The second surfactant is a water soluble inverting surfactant which, we believe, permits the inversion of the water-in-oil emulsion to an oil-in-water emulsion t $tot upon contact with the inherent or added moisture present .0 *1 in the mineral ore concentrate. Upon inversion of the water-in-oil emulsion the polymer is forced out of the internal aqueous phase and made available to the surface of the mineral ore concentrate. This release of the

A-

04 polymer onto the surface of the mineral ore concentrate allows for rapid commingling of the polymer with the mineral ore concentrate. Emulsions that do not contain inverting surfactants, or mixtures of emulsions which do and emulsions which do not contain inverting surfactants, can be used with this invention.

The surfactants suitable for use in forming emulsions of one embodiment of this invention are usually oil-soluble

I

1 4

S

S

*2 *5 5 I 1 t- 31a 32 pelymer onte the SuCRfOR o9 t-ha MINePRl oap oni allows for rapid commingling of the polyme;_ h the mineral ore concentrate. Emuls a that do not contain inverting surfactant n be used with this Invention.

The a actants suitable for use in forming 40iiiii n t invention are "upalyoi-lbl having a Hydrophile-Lipophile Balance (HLB) value of' from about 1 to about 10 and preferably from about 2 to about 6. These surfactants are normally referred to as water-in-oil type surfactants. Suitc.l*e surfactants 4*44 include the acid estevs such as sor'bitan monolaurate, sorbitan monostearate, sorbit--n, monooleate, sorbitan trioleate, mono and diglycerides, such as mono and :.116: diglycerides obtained from the glycerolysis of edible fats, polyoxyethylenated fatty acid esters) such as polyoxyethylenated sorbitan monosterate, ~polyoxyethylenated linear alcohol, such as Tergitol 15-S-3 and Tergitol-25-L-3 supplied by the Union Carbide Corporation, polyoxyethylene sorbitol esters, such as polyoxyethylene sorbita. beeswax derivative, polyoxyethylenated alcohols such as polyoxyethylenated cetyl ether, and the l~ike.

Water-soluble Inverting surfactants which can be used include polyoxyethylene alkyl phenol, polyoxyethylene (10 mole) cetyl ether, polyoxyethylene <IL: 1~' D-14, 834 10 49 i $4 4. 25 44 420 alkyl-aryl ether, quaternary ammonium derivatives, potassium oleate, N-cetyl N-ethyl morpholinium ethosulfate, sodium lauryl sulfate, condensation products of higher fatty alcohols with ethylene oxide, such as the reaction product of oleyl alcohol with ethylene oxide units; condensation products of alkylphenols and ethylene oxide, such as the reaction products of isooctylphenol with 12 ethylene oxide units; condensation products of higher fatty acid amines with five, or more, ethylene oxide units; ethylene oxide condensation products of polyhydric alcohol partial higher fatty esters, and their inner anhydrides (mannitol-anhydride, called Mannitan, and sorbitol-anhydride, called Sorbitan). The preferred surfactants are ethoxylated nonyl phenols, ethoxylated nonyl phenol formaldehyde resins, and the like.

The inverting surfactant is used in amounts of from about 0.1 to about 20, preferably from about 1 to about 10 parts per one hundred parts of the polymer.

The mixture of both the aqueous phase and the oil phase of the emulsions used in this invention can contain about 20 to about 50 and preferably from about 22 to about 42 percent weight of the hydrophobic liquid and the hydrophobic monomers, based upon the total weight of the composition.

i 72

D-

1 4,834 34 The aqueous solution used to form the emulsion systems of this invention can contain a mixture of water soluble monomers. These monomers have a water solubility of at least 5 weight percent and include acrylamide, methacrylamide, acrylic acid, methacrylic acid, and their alkali metal salts, aminoalkyl acrylate, aminoalkyl methacrylate, dialkylaminoalkyl acrylate, dialkylamino methacrylate and their quaternized salts with dimethyl sulfate or methyl chloride, vinyl benzyl dimethyl ammonium chloride, alkali metal and ammonium s. salts of 2-sulfoethylacrylate, alkali metal and ammonium salts of vinyl benzyl sulfonates, maleic anhydride, 2-acrylamide-2-methylpropanesulfonic acid, and the like.

t The preferred monomers are acrylamide, acrylic acid, and sodium salt of 2-acrylamido-2-methylpropanesulfonic f acid.

SSi" If acrylic acid is used as a monomer it is reacted with a base, preferably with an equivalent amount of base, such as sodium hydroxide, so that the sodium 20 acrylate solution has a pH of from about 5.0 to about 10.0, preferably from about 6.5 to about 8.5, depending on the type and amount of base employed. This solution is combined with another water soluble monomer, such as acrylamide, and then with water to form the aqueous phase.

the emulsion systems of this invention include one or more of vinyl esters such as vinyl acetate, alkyl acrylates such as ethylacrylate, alkyl methacrylates such as methacrylate, vinyl ethers such as butylvinyl ether, acrylonitrile, styrene and its derivatives such as alpha-methylstryrene, N-vinyl carbazole, and the like.

Appropriate reactors and catalysts are also used

S

ito Fan. This invention These c ompounds can varyticular 4 yemulsion or m ethod for producing an emulsion. fon in the Fan and Rosen patents identified aboveunt of water •i* Ssu Emulsions used sin this invention are made by any suitable method l A desirable mthehod fophr making emulsions is disclosed in U.S. Patent Number 4,485,209 .1 to Fan. This invention is not limited to a particular emulsion or method for producing an emulsion.

oilAn advantage to the se o aater-te-n-in-oil emulsions Sin the formation of pellets i thpato the amount ou ter ',20 added to the mineral ore concentrate is greatly reduced 4 from that required to deliver polymers in aqueous Sn solutions, thus resulting in an energy savings upon firing of the pellets Also, the hydrophobic liquid or oil in the Inverted water-in-oll emulsion system is consumed during the firing operation. The burn out of c sutbemto.Adsral ehdfrmkn D-14,834 36 the oil droplets from the interior of the pellets increases the porosity of the pellets in much the same manner as does the burning of the organic binder or polymer from the interior of the pellets. This increase in porosity is believed to improve the release of water vapor from the pellets and decrease the occurrence of thermal shock upon firing of the pellets.

An additional benefit realized by the use of a water-in-oil emulsion system to deliver a polymer binder i..a0 to mineral ore concentrate in pelletizing operations is Sa decrease in the amount of contact time required for Ssufficient commingling of the polymer binder with the i f 4 mineral ore concentrate. The contact time of a polymer after the emulsion is sprayed onto the mineral ore concentrate need only be sufficient to allow activation of the polymer on the surface of the mineral ore 444 Sconcentrate. The amount of time can vary depending upon the emulsion system used and the concentration of the polymer binder within the mt system as well as the total amount of polymer binder sprayed upon the mineral ore concentrate. In desirable embodiments of this invention, sufficient time for commingling of the polymer binder system into the mineral ore concentrate Soccur by spraying the water-in-oil emulsion onto the mineral ore concentrate -n upstream of where the concentrate enters the balling apparatus.

Application of water-in-oil emulsion -r other diporoio -in a non aqueous dispersion medium. at the mineral ore concentrate treatment site can be accomplished by applying the emulsion o- to the mineral ore concentrate through any conventional spraying or dripping apparatus. The inorganic salts are sprinkled from a vibrating hopper or other dispersing means onto the mineral ore concentrate and the composition is conveyed towards the balling apparatus.

*940 Alternatively, salt can be delivered from aqueous solutions of 0 about 5 to about 40 percent solid material depending on the solubility of the inorganic salt and the temperature. The 0, activation of the polymers onto the surface of the mineral ore 0 0* concentrate is rapid, and because the polymers are evenly spread or commingled throughout the mineral ore concentrate, the time required for sufficient commingling to initiate pellet formation is usually about one minute or less.

9 99 This invention also includes the application of binding polymer systems to mineral ore concentrate that are dry powders. In these embQdiments the dry powdered polymers are S mixed together optionally with the dry inorganic salt. The resulting powder composition is sprinkled onto the mineral ore concentrate as the concentrate is conveyed towards the balling Sapparatus. The vibration of the conveyor means and the action of the IA 37 4 44 4 4 44 4.

4 4 444 *4 4 044 I 44 44 4 *44 4 15 44 4 444.

4 44 44 4 4 44 *4 4 1 20 4 4 4.44 4l 4 4 .4 4 44 balling drum commingles the powders into the mineral ore concentrate. Upon su,~fficient contact time with the moisturet in the mineral ore concentrate, the polymers are adsorbed onto the surface of' the concentrate.

Suitable contact time can be essentially instantaneous, but often is between about 1 minute to 3 hours or more.

Further commingling occurs in the mixing within the balling drum. The use of' the dry powder polymer embodiments of' this invention eliminates the need for emulsion spraying equipment. This invention also includes the application of' powdered binders to a mineral ore concentrate in conjunction with an application of' inorganic salt as an aqueous solution.

Th. range of' t A-ncontration of' the polymer on an active basis is between about 0.0.0 percent to about 0,3 percent based on weight of' bone dry concentrate. The preferred range is be een about 0.001 percent and about 0.1 percent. Th e ranges are applicable for both dry and e lsified applications of polymer binders. The us ful range of' the concentration of' the inorganic sa based upon the weight of bone dry concentrate Is etween about 0.001 percent and about 045 percent w the preferred range being between about 0.00 percent and about 0.3 percent.

__9 While the process of this invention comprises using polymer/4 or dry powders alone, it also comprises their use with other materials such as bentonite. In a preferred method of practicing the present invention, the water-in-oil emulsion contains approximately 30 weight percent of a copolymer (prepared from approximately 50 weight percent acrylamide monomer and 50 weight percent sodium acrylate monomer), 35 weight percent water, 35 weight percent Isopar M, Sand a nonyl phenol ethoxylate as a surfactant. Before spraying onto taconite concentrate, the emulsion may be S• filtered to remove gels which might clog the spray nozzle. The emulsion is added at the rate of about 0.6 pounds per tonne.

A cit~lA P capioh S7SS( In -ccordance with the invention of 'li f=i fl,: bentonite ma; also be added at the rate of 9 pounds per tonne.

Preferably, the bentonite is adder after the emulsion and just t before the taconite concentrate enters the pelletizing drums or discs.

«rp;roQcesG- of this -invention may al1Fo.-'Q be- 4ed- t-Q flux pellets. These pellets are made by adding to t I taconite concentrate an inorganic material th t-e nds to reduce the acidity of the resulting pellets. e inorganic material may be one or more of the follow' g: dolomite ((Ca,Mg)CO0), high calcium dolomite (al known as limestone or calcium carbonate) and mag ium carbonate. These may be added prior to, simulta usly with, or after the addition of the polymer to th iuatculate naterial. Flux pellets are sometimes O -nto rm of their b38aity h raio of bases

T

Z z 38a l-l f'\ c C4- L .LJ4..L L a. V-J. 5 u t# 4. 5 S j i A1 2 0 3 When basicit e flux pellets may 2~rrrL 34'.L t J U '"-ySJ~uu.Mjy Av a P uAujujA J.IUL Y.UI Pao V- R iH i.

The useful range of the concentration of the polymer on an active basis is between about 0.001 percent to about 0.3 percent based on weight of bone dry concentrate. The preferred range is between about 0.001 percent and about 0.1 percent.

These ranges are applicable for both dry and/ form applications of polymer binders. The useful range of the 0o concentration of the inorganic salt based upon the weight of bone dry concentrate is between about 0.001 percent and about 0.5 percent with the preferred range being between about 0.005 percent and about 0.3 percent.

The invention is further understood from the

I

4 44 4 d

I

4 I 4 .4.

'4 44

I

I

I I I 41 1 I t C t I 41 2

I

iII II I 4 4 38aa

V

These examples show that mechanical properties of

P

s-4 D-14,834 Examples below, but is not to be limited to the Examples. The numbered Examples represent the present invention. The lettered Examples do not represent this invention and are for comparison purposes. Temperatures given are in °C unless otherwise stated. The following designations used in the Examples and elsewhere herein have the following meanings: *4 4 4 t at i t V 4 44 4 t 44 44 4 t tr r

ABBREVIATION

AM

Apx.

CaCO 3 cc

CMO

CMC

CO2 dl/g

OF

gm/cc gms

HEC

IV

lb mm NaA NaAMPS

DEFINITION

acrylamide approximate calcium carbonate cubic centimeter carboxymethylcellulose carbon dioxide deciliter per gram degrees fahrenheit grams per cubic centimeter grams hydroxyethylcellulose intrinsic viscosity pound or pounds millimeters sodium acrylate sodium salt of 2-acrylamido I 1 i 4 44« t D14 834I p ,g pp o o p p op o p ~p, p pp p p 4 pp. p p o p p 04 op p p~ p.

PP 0 R4* 0 0 P4 pp *4 9 9 0* p NaC 1 (NaPO 3 )n Na 2 O0

PAM

psi

RPM

RV

tonne

U.S.

VA

W t wt -2-methyipropanesulfonic acid sodium chloride sodium metaphosphate where n is 2 or more sodium carbonate sodium oxide poly (acrylamide) pounds per square inch pressure revolutions per minute reduced viscosity metric ton United States vinyl acetate weight weight percent percent by weight unless otherwise speoified 1I~.IP-~~rr D-14,834 41 StLABORATORY EXPERIMENTAL PROCEDURE In these Examples taconite pelletizing consists of a two step procedure. Initially, seed balls P e prepared from the taconite ore using bentonite clay as a binder.

These seed balls are passed through screens to obtain seed balls of a size that pass through a 4 U.S. mesh screen having a 0.187 inch opening, but not through a 6 U.S. mesh screen having a 0.132 inch opening. The seed balls are then used with additional concentrate and the binder of interest to prepare the larger green pellets.

0 6 10 Finished green pellets are sieved to be in a size range between 13.2mm to 12.5mm. This can be accomplished by a 0 Susing USA Sieve Series ASTM-E-11-70. Following sieving, the green pellets are tested for wet crushing strength and wet dropping strength. Additional green Sa 15 pellets are dried (not fired) and tested for both dry 9 9 crushing and dry dropping strength. For the examples cited, all testing was done with either wet or dry green pellets.

S* Seed ball formation in these examples is begun with o0 20 a sample of 900 grams (bone dry weight) of taconite I concentrate containing between 8 to 10% moisture. The concentrate is sieved through a 9, 10, or 12 mesh screen and spread evenly over an oil cloth. Next grams of bentonite clay is spread evenly over the top of i i 2 B-: D-14,834 00 4 0 04 -4 soI 9 49 O 20 Or 9 **4 the concentrate and mixed until homogenous. The mixture is incrementally added to a revolving rubber drum having approximately a 16 inch diameter and a 6 inch cross section. The drum is rotated at 64 RPM. Humidity is not controlled in these Examples. Just prior to addition of concentrate, the inside of the drum is wet with water from a spray bottle. While rolling, several handfulls of the bentonite-concentrate mixture is added to the drum. Distilled water is added when the forming agglomerates begin to develop a dull appearance. As seed pellets are formed, they are screened to separate and obtain pellets which pass through a 4 mesh screen, but not through a 6 mesh screen. Captured fines are readded to the balling drum and oversized seeds are rejected. The procedure of readding captured fines is repeated several times until sufficient seed pellets of the desired size have been produced. The seed pellets are then rolled for one minute to finish the surface.

Formed seed pelleta can be placed in a sealed container containing a damp cloth so as to retard dehydration of the pellets.

Green pellet formation in these Examples is begun with a\ sample of 1800 grams (bone dry weight) of mineral ore containing between 8 to 10% moisture. The concentrate is added into a 12 inch diameter Cincinnati D-14,834 43 Muller and mixed for 1.0 minute. Thereafter, an amount of binder to be used in the Example is uniformly distributed over the surface of the concentrate. In Examples using emulsion polymers, the Pfl-13f-ip--i polymers are uniformly delivered dropwise from a syringe. When an inorganic salt, such as Na 2

CO

3 is used in an Example, it is sprinkled over the surface of the concentrate. For those examples which employ a Na2CO 3 solution, a 30 percent salt solution is used.

For those examples which employ powdered polymers, the *powder is dry blended with the inorganic salt and the resulting mixture is then uniformly sprinkled over the concentrate in the muller. The muller is then turned on t for three minutes to mix the binder with the concentrate. The uniform mixture is then screened through an 8 mesh screen.

S After moistening the inside of the rotating balling drum of tire, about 40 grams of seed pellets are added to the tire. Then the concentrate and binder mixture is incrementally fed into the tire over a period of six Qminutes with intermittent use of distilled water spray.

During the initial portion of this process, small amounts of the concentrate and binder mixture are added each time the surface of the pellets appear shiny.

Typically, the latter portion of the six minute rotating of 'i D-14,834 44 period requires an increased amount of the concentrate and binder mixture when compared to the initial part of the rotating period. Water spray is applied each time the surface of the pellets takes on a dull appearance.

After the six minute rotating period is complete, the balling drum is rotated one additional minute to "finish off" the pellet surface. No water spray is used during the final one minute period. Following dompletion of this procedure, the green pellets are screened for testing purposes to a size between 13.2mm and 12.5 mm.

Compression testing in these Examples is performed by using a Chatillon Spring Tester of a 25 pound range (Model LTCM Serial No. 567). Twenty green pellets are crushed in the tester within 30 minutes of pellet t completion at a loading rate of 0.1 inches per second.

F •i The pounds of force required to crush each pellet is taveraged for the twenty pellets and is herein called the wet crush strength. An additional twenty pellets are dried for one hour at 350 0 F. While these pellets are S'I" still warm to the touch, the crushing procedure is I repeated to obtain the dry crush strength average measured in pounds per square inch (psi).

Drop testing in these Examples is performed with twenty green pellets which are tested within 30 minutes

I

D-14,834 57

EXAMPLE__VII-------=

r -1 D-14,83J4 rttt 10 t t SA I t r t I

IL

I2 ta I I;

I~

r 8 of their formation. These pellets are dropped one at a time from a height of 18 inches onto a steel plate. The number of drops to obtain pellet failure is recorded.

Pellet failure is determined when a crack in a pellet of approximately a 0.7 mm or greater occurs. The average for twenty wet pellet drops is reported. Twenty additional green pellets are dried by the procedure set out for the compression test and then each is dropped from a 3 inch height. The average number of drops to obtain pellet failure for twenty pellets is determined and recorded.

Definition of acceptable or.target pellet mechanical properties is defined in these Examples, within limits of experimental error, by a comparison to the performance of Peridur, a commercial binder. Peridur was analyzed to be 68 percent carboxymethylcellulose with about 16 percent NaC1 and about 16 percent Na 2

CO

3 Peridur is known to produce acceptable results in some plant scale pelletizing operations at a dose of 1.55 lb product/tonne of concentrate. Since the product is about 68% sodium carboxymethylcellulose, Peridur is used at an active polymer dose of about 1.05 lb/tonne. Peridur is sold by Dreeland Colloids, 1670 Broadway, Denver, Colorado.

Wet drop numbers above about 2.5 and wet crush 1 D-14,834 46 numbers above about 3.0 are useful. Dry drop numbers greater than about 2.0 and dry crush numbers above about 4 are acceptable. Comparisons of pellet mechanical properties for different binders need to be made at approximately equal pellet moisture contents. Wet pellet properties are important because wet pellets are transported by conveyors and are dropped from one conveyor to another during their movement. Dry properties are important because in kiln operations pallets can be stacked 6 to 7 inches higyor more. The Spellets at the bottom of such a pile must be strong enough so as not to be crushed by the weight of the pellets on top of them. Dry pellets are also conveyed and must resist breakage upon dropping.

Unless otherwise stated in the following examples, the term, water-in-oil emulsion, refers to a water-in-oil emulsion containing an inverting surfactant. In these emulsions the oil phase is Isopar M.

to

O

*1 D-14,834 EXAMPLE A The experimental procedure described above was used to prepare and test two samples of green pellets of taconite concentrate formed with a commercial CMC/NaC1/Na 2

CO

3 binding agent system. The amount of binding agent used and the results are presented in Table III.

TABLE III lb Peridur per tonne 1.18 lb active polymer/ tonne 0.80+ wet wet crush drop 4.6 2.7 4.6 2.5 dry wet crush drop 4.2 2.1 4.8 2.1

H

2 0 9.2 t i IiI It carboxymethylcellulose EXAMPLE I The experimental procedure described above was used to prepare and test two samples of green pellets of taconite concentrate formed with a PAM/NaA/VA binding agent in a water-in-oil emulsion. The mole percent of PAM/NaA/VA is The oil used in the external phase was Isopar M. The intrinsic viscosity of the polymer was 23 dl/g. The amount of binding agent used and the results are presented in Table IV.

It It 1 iI

_I

I

r is I I C I i D-14, 834 TABLE XIII r\ a' t .1 i /i r t n r 7 D-1 1 4,834 TABLE IV lb emulsion per tonne 1.36* 0.91 lb active polymer'/ tonne 0.140 0.27 wet wet cr'ush dr'op 4.0 4.5 3.5 3.0 dry dry cr'ush drop 4.9 2.7 3.6 2.14 Hi22 9.1 9.1 also contains 0.78 lb Na 2 00 3 /tonne 41 4 1 14 This example shows that the dual addition or an emulsion containing the polymer der'ived fr'om acrylamide, .,odium acrylate, and vinyl acetate in a mole -4e along with Na 21CO 3produce a taconite binder which is superior to the binder system used in Example A which employs a OMO/NaCl/Na 2 00O 3 binding agent. At one half the active polymer dose the PAM/NaA/VA-Na 2 00O 3 system gave a higher wet drop number than the control binder, of Example A.

EXAMPLE B The experimental procedures desribed in Examples A and I were Used to pr'epare and test the green pellets of taconite concentrate in this Example. The pellets of this Example are formed with either a commerical CMC/NaCl/Na 2CO 3 or HEO/Na 2 00 3 binder system. The concentration and test results are in Table V below.

D-14 P 83 TABLE V lb active polymerl binder tonne HEC/Na 2 00 3 0.78 CMO /NaCl/ Na 2 C0 3 1.05 wet wet crush drop 3.3 3),0 4.0 2.9 dry dry crush drop 4.0 5.4 2.8 1!2 I'tt I

II

I II I I III I It I I I II I I~ C I

III

5 0 /50 M i Xt Ure, c -<7I g6 cp 1 pev- A-rzY-Nv-e.

68/16/16 wt% (average off 3 runs) EXAMPLE II The experimental procedu~res described in Examples A and I were used to prepare and test green pellets of taconite concentrate formed with a PAM/NaA/VA binding agent in a water-in-oil emulsion. The mole percent of PAM/NaA/VA is The oi1 Used in the external phase was Isopar M. The concentration and test resulltvs arle in Table VI below.

II~~

II

I I I It w D-1'4,834 TABLE VI lb active polymer! wet wet dry dry tonne crush dr~op crush drop H 2 0 H PAM/NaA/VA- 03*C 0.78 3.3 6.2 6.8 '4.3 9.8 Tais is a 50/50 mixtureti/P',M/NaA/VAhaanIof1. lg IThi Example shows that the dual addition of a of PAM/NaA/VA binding system with a lower molecular weight as evidenced by an IV of 10.3 in a 5 binder system Which is superior to the current art employing combinations of hydroxyethylcellu)lose/Na 2 3Oo carbo~ymethylcellulose/Na~l/Na O 3 Note that Wet drop number, dry crush and dry drop were all better with the PAM/NaA/VA-Na 2 0CO binder system.

EX.AMPLES C AND III The procedures for preparing and testing the green pellets in these Examples were the same as described for Examples A and I. These Examples compare pellet strength resulting fr'om varying concentrations of pol~ymer binder systems. The concentrations and test results are in Table VII below.

A

~lh.

TABLE VII Example total dose+ lb/tonne ActIve polymer Dose ib/tonne wet wet crush drop dry dry crush drop

III

III

PAM/NaA/VA* Na 2 CO 3 C!MC/NaCl/ Na 2 CO 3 PAM/NaA/VA* Na 2 C0 3 CMC INaCl Na 2 CfO PAM/NaA/ VA* CMC /NaC1 Na 2 CO 3 1 r5 1i.55 1.17 1.17 1.00 1.00 0.78 1.05 0.39 80 0.22 0.68 3.2 1n.6 5.6 2.7 5.3

III

3.6 -4.2 3.5 3.9 10.0 3.14 4..2 2.6 4.14 3.0 3.14 2.5 2.9 2.0 2.2 2.1 2.5 2.1 8.8 8.7 8.2 8.9 lb active polymer plus lb Na202O *intrinsic viscosity 23, mole prcn 5Lf q. zh-1 N7"TL'77 D-14,834 52 These examples show that mechanical properties of taconite pellets formed with a PAM/NaA/VA binding agent in a water-in-oil emulsion improve with increasing dose.

Comparison of the poly(acrylamide) based polymer binder system in Example III .as made at each concentration to a CMC/NaCl/Na 2

CO

3 binder system in Example C.

EXAMPLE IV The procedures for preparing and testing the green 4:I* pellets in this Example were the same as described for Example I. This Example Compares the effect of intrinsic viscosity on pellet strength for a poly(acrylamide) based polymer binder system. The intrinsic viscosities and test results are in Table VIII below.

.4 4 tC 14 53

D-

1 4,834 53 TABLE VIII DOSE: 0.78 LB ACTIVE POLYMER/TONNE wet wet dry dry IV crush drop crush drop 10.8 2.8 8.1 5.4 4.3 10.3 23.0 3.2 11.6 5.6 4.1 10.1 Mole percent of PAM/NaV/VA and also contains 0.78 pounds Na 2

CO

3 per tonne.

This example shows that polymer binder systems of higher intrinsic viscosity produce better mechanical

OC

pellet properties with taconite concentrate when the polymer binder is a PAM/NaA/VA terpolymer.

5 EXAMPLE V The procedures for preparing and testing the green pellets in this Example were the same as described for Example I. This Example compares the effect on pellet strength occurring when the mole ratios of a polymer's 0. 0- 10 monomers are varied. The mole ratios and the test results are presented in Table IX below.

7/ 0 4,.

a o a a 4*N *0a 400 0 S 44 4* 0 0~ 0* 0 *4 0 4 4 a a 4 a a0* a a 4 a 4 TABLE IX Dose: 0.22 lb active polymer/tonne plus 0.78 lb Na 2Co /tonn Polymer Composition mole percent PAM /NaA /VA 71/214/5 2 80/15/5~ wet wet crush drop dry dry crush drop H2O 4.1 3.9 3.0 4.0 3.14 3.14 14.14 4.7 2.5 8.9

U,

2.0 2.7 8.2 PAM/NaA 4 59/41 .3.8 3.0 3.8 2.1 8.8 IV 23.0 dl/g, 2. IV 20.0 dl/g, 3. RV 17.5 dl/g, 4. Approximately 29.5% active polymer 30% active polymer 30% active polymer IV 20.0 dl/g, 30% active polymer D-1 1 4,834 This Example shows that NaA between about 15 and about/:*'",*ni=ole percent was not critical to achieve satisfactory performance In an acrylamide polymer.

EXAMPLES D A~ND VI 5 The procedures for preparing and testing the green pellets in this Example were the same as described for Examples A and I. The concentrations and test results are in Table X below.

r D-14I, 8314 TABLE X DOSE: 0.39 LB ACTIVE PAM COPOLYMER/TONNE PLUS 0,7~ LB Na CTo Example

VI

VI

VI

VI

D

Copolymer mole PAM/NaA 59/1411 76/24 2 85/153 powder

CMC

.C ont rol wet wet crush drop 3.4 5.5 3.3 4.2 3.7 4.9 3.4 2.5 4.2 2.6 dry dry crush drop 4.4 2.5, 4.6 2.8 4.8 2,3 4.4 3,3 9.1 8.1 4.4 2.1 8.2 *(1,05 lb emulsion/tonne).

1. IV approximately 20 dl/g.

2. IV 17.3 dl/g.

3. IV 16.2 dl/g.

4. IV 15.4 dl/g, this powder is AD-lu sold by Rhone Poulenc.

1.17 lb/tonne (containing 0.8 lb OMOC polymer/tonne).

These Examples show that acrylamide copolymers containing 0 to at least 41 percent Na acrylate are effectivG as binding agents for taconite concentrate.

II

p t r t 41 EXAMPLE VII Except for the use of polymer in powder form and sprinkling the dry powder onto the concentrate, the procedures for preparing and testing the green pellets in this Example were the same as described in Example I. The concentrations and test results are in Table XI below.

I t S t t S t 2 0 56a j i D-14,834 The procedures for prepar~ing and ng the green pellets in this Example the same as described in Example I e concentrations and test results are in TABLE XI Dose: As shown 0.78 lb Na 2 20 3 /tonne 42 44 4 44 1 4 14 4 ~rt 4

I

4* 4 4 4, 4 4 I 44 41 It~ I active copolymer polymer mole dose PAM/NaA lb/tonne 89/11 0.78 77/23 0.78 These Examples based copolymers in agents for taconite wet wet crush drop 3*9 4.4 3.7 6.9 show that solid powder' form are concent rate, dry dry crush drop 6.8 3.1 7.9 3.3 poly (acrylarnide) effective binding 9.2 9.1 jil' 4444 10

I

4.44 44 I 4 44 EXAMPLES E AND VIII The procedures for preparing and testing the green pellets in these Examples were the same as described in Examples A and I. The polymer binder system used and the test results are in Table XII below.

ri 58 D-14, 834 TA KLE XII Dose of PAM based polymers 0,,39 lb active/tonne 0.78 lb Na 2 00 3 /tonne wet wet dry dry Composition crush drop crush drop 12 PAM/N Decyl Acrylamide 2.7 3.0 4.7 3.0 (99/1) nonionic PAM/Sipomer Q5-80 1 3.1 2.4 4.4 2.8 8.4 94/6 cationic if CMO/NaCl/ NaC (cn~l4.2 2.6 4.4 2.1 8.2 tj~ it: Sipomer Q5-80 is Dimethylaminoethylmethacrylate/Dimethyl d ~:'sulfate quaternary salt.

20.8 lb OMO/tonne.

These Examples, show that fmulsions of nonionic poly~acrylamide) based polymers with long chain Ihydrophobic groups and cationic modified PAM perform t well as taconite binders when compared to CMC based products. The results obtained from these Examples demonstrate that an emulsion of PAM/NaA/VA is better I. than or roughly equivalent to a CMO/Naul/Na 2 C0 binding 2' 3 agent in both drop teets and compression tests.

Y D-14,834 59 EXAMPLE IX The procedures for preparing and testing the green pellets in this Example were the same as described in Example I with the exception that the inorganic salt used in this example is applied as a 30 percent aqueous solution. The polymer binders in this example are in a water-in-oil emulsion. These tests were conducted on taconite ore concentrate and demonstrate the effect of applying the polymer binder emulsion and inorganic salt Ssolution in different sequences to the mineral ore 1 0 concentrate. When these liquids are applied to the I mineral ore concentrate separately, the first liquid is mixed with the mineral ore concentrate in a muller. The second liquid is then added and the total composition is mixed for an additional 3 minutes. The test results are presented in Table XIII below.

i-

I

t- 1- 1 D-14,834 TABLE XIII Dose: emulsion 1.1 Ib emulsion /tonne Na 2 CO 0.81 Ib/tonne Method of Addition Total Minutes of Mixing Wet Wet Drop Crush Dry Dry Drop Crush Water Emulsion 2 6 then NaCO0 3 Solution 3 Na 2 CO Solution 6 then Emulsion 3 Emulsion and Na CO Solution Applied Together 3 6 6.7 3.8 2.3 5.2 8.9 8.4 3.7 2.0 4.0 9.1 5.2 3.7 2.2 4.8 1The emulsion contains 27.6 percent active polymer.

The emulsion was PAM/NaV/VA in a mole percent of 7s l 11 j The emulsion and inorganic salt solution were applied concurrently to the taconite ore concentrate from separate containers.

D-14,834 61 This example demonstrates that an inorganic salt solution can be applied in conjunction with polymer binders to effectively agglomerate a mineral ore concentrate.

EXAMPLE X This Example was conducted on taconite concentrate in the same manner as Example I. This example compares the effectiveness of a binding agent in a water-in-oil emulsion both with and without an inverting surfactant.

This test involved a two-step addition. The Na 2 00 3 powder was added to the taconite concentrate and mixed for three minutes. The emulsion was then added and the entire composition was mixed an additional three minutes. The test results are presented in Table XIV.

D-14,834 TABLE XIV Wet Wet Dry Dry Drp Crush Drop Crush Water Emulsion with inverting surfactant 5.1

EI

surfactant 3.7 3.9 3.9 2.0 44 2.0 3.6 8.3 54- 1* X 0th emulon co~in PAM/NaA/VA in a mol ra~-atM~ouids of emulsion per tonne and 0.81 pounds Na 2 00o 3 per tonne.

-J

D-14,834 63 This experiment demonstrates that acceptable green S* pellets are.formed both with and without an inverting surfactant in the emulsion.

r A r i ii i i i 1*.tt D-14,834 64 EXAMPLES F ANE XI The following Examples were conducted in full scale plant with a full size balling drum and kiln. In these Examples 55 tonnes per hour of taconite concentrate were conveyed to and processed in the balling drum. The selected binding agent systems were added by spraying onto the taconite ore concentrate just prior to entering the balling drum and by vibrating the Na 2 C0 3 powder onto the taconite ore concentrate. The average contact time of the binders with the mineral ore concentrate before entering the balling drum was approximately 0.5 to 1 minute. The average size of the green pellets obtained were between approximately one-fourth to one-half inch in diameter.

In Example XI an anionic water-in-oil emulsion of PAM/NaA/VA in a mole percent of%'7 .5/7 was used as a polymer binding agent. The quantities of binding agents used and the results obtained by the poly(acrylamide) based polymer binUing agents are detailed in Table XV. Comparative results for other binding agents are in Table XVI.

D-14, 8311 TABLE XV Example

XT

*X1I

AXI

x I Test 1 Number 1 2 3 41 5 6 7 PAM/NaA/VA gal! lb/ min tonne 0.1415 1.415 0 0 0.1415 1.415 0.10 0.941 0.11 ,.05 0.114 1.34 0.12 1.12 lb/ lb/ min tonne 0.73 0.80 0.73 0.80 0.00 0.00 0.73 0.80 0.37 0.410 0.95 1.011 1.70 1.85 Wet Compression psi Wet 181, drop Dr2 Compression psi 1.5 1.6 2.1 2.1 8.14 2.3 7.0 1.8 10.6 2.8 9.6 3.1 44 I *4 D-1 1 4, 83 1 1 TABLE XV CONTINUED Test Number Cont.

1 2 3 14 6 Avg. Fired 3 Compress ion psi 320 1914 118 259 of Fines That Break Under 200 psi 19 63 50 85 42 Feo 0.4I~3 0.35 0.31 5.1 0.31 1!2 9.6 9.2 10. 1 10.1 9.14 9.8 18"1 Drop Min. after start of binde; addition 10 20 16.0 7.3 7.6+ 6.0 4.2 3.6 4.5 11.1 9.3 8.7 7.8 8.5 8.0 9.3 8.0 10.5 18.7 13.2 6.6++ 12.5 12.1 11.9 r t r- i D-14,834 TABLE XV CONTINUED Size Distribution of Pellets Test Number Cont.

1 2 3 4 +1/2" 2.2 13.6 2.9 4.7 2.7 1.4 1.2 1.9 +7/16" +3/8" +11/32" +1/4" 7.8 1.4 -1/4" 1.8 43.2 57.1 33.5 31.8 27.9 45.4 14.1 22.5 43.7 19.9 40.8 46.4 44.6 44.3 58.6 57.9 4.8 14.3 8.5 15.1 6.8 20.2 12.9 2.1 4.8 2.8 4.6 1.1 3.8 2.8 3.7 5.9 5.1 2.1 1.9 Iz I 1 Samples were obtained by filling a basket with green pellets, transporting the basket through the kiln operation, and testing pellets from the top, mid-top, mid-bottom, and bottom of the basket.

2 Pellets contain no moisture, samples are taken just prior to kiln operations.

3 Samples are taken after drying in kiln.

48 MIN 40 MIN tt

A

-TAOLC- XVTI Dry carjpression psi Test Exaple number F CMC/NaCl Na CO (cgnt~ol) 1lb/tonne F CMC/NaC1 2lb/tonne F Bentonite* (typical values) Wet xlmpression psi 1l.3 (Apx.) 1 .3 (Apx.) 2.2 to 2.7 Wet 18"1dro Average fired carpression psi of fines that break under 200 psi water 5.0(Apx.) 5.0(Apx.) 7 to10 5 to 6 1440 Apx. 18 Ib/tonne.

coId

I

~-ilj These Examples show that, while use of polymer of this invention with no Na 2

CO

3 produced pellets with good mechanical properties such as high green drop, the 18 inch drop number for wet green pellets and the dry compression strength of dry pellets improve with increases in Na 2

CO

3 concentration. Varying the concentration of Na 2

CO

3 did not show a trend in the compression strength of fired pellets.

The words "Percol", "Insopar", and "Peridur", as used herein, are acknowledged as registered trade marks.

L It Ii t ii t t t it s I0 t6t 69-

Claims (5)

1. 7. The process of any one of claims 1 to wherein said polymers are derived from at least one of the following groups of monomer units: acrylamide, methacrylamide and derivatives thereof of the formula: R 13 0 R 14 CH 2 C C- N where R 13 is a hydrogen atom or a methyl group; R 14 is a hydrogen atom, a methyl group or an ethyl group; R 15 is a hydrogen atom, a methyl group, an ethyl group or -R 16 -SO 3 X, wherein R 16 is a divalent hydrocaibon group having r 1 to 13 carbon atoms and X is a monovalent cation. 7 The process of any one of claims 1 to X wherein said polymer is applied to said particulate material at an active polymer concentration between 0.001 to 0.3 percent by weight. The process of any one of claims 1 to9 wherein an inorganic salt is commingled with said particulate material, said particulate material being mineral ore concentrate. S o20 The process of claim wherein said inorganic salt is an alkali metal oii or alkaline earth metal salt of carbonates, halides, or phosphates, or a mixture thereof, and said mineral ore concentrate is taconite concentrate. '1 The process of claim wherein said inorganic salt is at least one member selected from the group consisting of sodium carbonate, calcium carbonate, sodium chloride, and sodium metaphosphate. Jol The process of claim 10 wherein said inorganic solt is applied to said mineral ore concentrate in an aqueous solution. -72 e ,r ic~ ;~i 67 I I Ir t. The process of claim f(wherein said inorganic salt is applied to said mineral ore concentrate at a concentration between 0;001 to 0.5 percent by weight of concentrate. L.Z. The process of claim 2 wherein said water-in-oil emulsion has an oil phase selected from the group consisting of benzene, xylene, toluene, mineral oils, kerosenes, paraffinic hydrocarbons, petroleum, Isopar and mixtures thereof. is.3: The process of claim 2 wherein said emulsion contains an inverting surfactant. A product of the process of claim 1, f7..7 The process of any one of claims 1 to -M wherein green pellets of mineral ore are obtained by agglomerating said particulate material and said Sgreen pellets are then fired by a means for applying heat sufficient to indurate I II said ore. Is 1 Vg T' process of claim, wherein said sufficient heat to indurate said S pellets is above 1800, F 1 The process of claim n wherein said sufficient heat to indurate said pellets is about 2800'F. 3 0 A product of the process of claimsa Wr.29; 4g A process of producing pellets comprising: selecting a water-soluble poly(acrylamide) based polymer in mixing a binding quantity of said polymer with a taconite concentrate; pelletizing in a balling apparatus the mixture of step to form pellets; and
2. 73- 1 indurating said green pellets with heat. .P4 rFi-ia heeierh uin Q vwtaa The process of claim 3 wherein said polymer contains repeating units selected from the group consisting of units of the formula: R3 I R14 CH 2 =C C-N wherein R 13 is a hydrogen atom or a methyl gkoup; R 14 is a hydrogen atom, a methyl group or an ethyl group; R 15 is a hydrogen atom, a methyl group, an ethyl group or -R 16 -SO 3 X, wherein R 16 is a divalent hydrocarbon group having 1 to 13 carbon atoms and X is a monovalent cation; units of the formula: CH-- C -CH- 2 C 2 I I S,c «NH 2 O- 2 R 2 g d S wherein R 2 is an alkali metal ion, f and g are from 5 to 90 percent, f g 100, and d is from 1,000 to 500,000; and mixtures of such units. .37' The process of any=-o=of claim Wi4erf f wherein an inorganic salt is also mixed with the concentrate, said inorganic salt being an alkali metal or an alkaline earth metal salt of carbonates, halides, or phosphates, or a combination thereof. 2 The process of claim wherein said inorganic salt is applied to said mineral ore concentrate in a concentration between 0.001 to 0.5 percent by weight
3. 74- r t 1 ii I; -I -i i 59 ao, '4 444, 44C 0 l Ij*;4 4 0 @4d 4 44, 4 and wherein said polymer is applied to said mineral ore concentrate at an active polymer concentration between 0.001 to 0.3 percent by weight. 27 A product of the process of any one of claims/~Fte~ A process of agglomerating a particulate material, comprising: ,Po ex p«Jtd f I N IKUJ-4e 0r vor& commingling said particulate material with a water soluble poly(acrylamide) based polymer, wherein said polymer is applied to said particulate material as a dry powder. '2 The process of claim2@wherein said polymer contains repeating units of the following formula: H H CH C CH 2 C=O C=O NH 2 O' R 2 7g d wherein R 2 is an alkali metal ion, f and g are from 5 to 90 percent, f g 100, and d is from 1,000 to 500,000. 27 S The process of claim .f9 wherein said polymer is derived from monomer units of acrylamide and sodium acrylate. t4 1 The process of claim.Wwhjrein said polymer contains repeating units of the following formula: 25 R R R S* 1 2 C CH2--- C -CH- I I C=0 C= R4 NH c a b d b R 2 d ro^. 7_75 wherein R, R 1 and R 3 are independently hydrogen or methyl, R 2 is an alkali metal ion, R 4 is either -OR 5 wherein R 5 is an alkyl group having up to 5 carbon atoms, O II C O- R 6 wherein R 6 is an alkyl group having up to 8 carbon atoms; O II O C R 7 wherein R 7 is either methyl, or butyl; phenyl; substituted phenyl; 4 -CN; or (7) S; and N tIO' hydrolized tetrapolymers thereof, trs wherein is from 5 to 90 percent, is from about 5 to 90 percent, is from S0 to 20 percent, 100, and is from 1,000 to 500,000. 4 33. The process of claim .M wherein said polymer is derived from monomer units of acrylamide, sodium acrylate, and vinyl Ecetate. 31 .3 The process of claim wherein said polymers are derived from at least one of the following groups of monomer units: acrylamide, methacrylamide and derivatives thereof of the formula:
4. 76- R 1 3 0 R 1 4 CH2C C-N R 1 where R 13 is a hydrogen atom or a methyl group; R 14 is a hydrogen atom, a methyl group or an ethyl group; R 15 is a hydrogen atom, a methyl group, an ethyl group or -R 16 -SO 3 X, wherein R 16 is a divalent hydrocarbon group having 1 to 13 carbon atoms and X is a monovalent cation. 3C 31 0< The process of any one of claims/ W F !AW wherein said polymer is applied to said particulate material at an active polymer concentration between 0.001 to 0.3 percent by weight. 33 The process of any one of claim O.fte~ e wherein an inorganic salt is commingled with said particulate material, said particulate material being a mineral ore concentrate. 33 S 36. The process of claim 4 wherein said inorganic salt is an alkali metal or alkaline earth methl salt of carbonates, halides, o- phosphates, or a mixture II. thereof, and said mineral ore concentrate is taconite concentrate. 33 ,ss',ff. The process of claim .3f wherein said inorganic salt is at least one member selected from the group consisting of sodium carbonate, calcium S carbonate, sodium chloride, and sodium metaphosphate. 363 The process of claim Awherein said inorganic salt is applied to said mineral ore concentrate in an aqueous solution or slurry. The process of claim 3 wherein said inorganic salt is applied to said mineral ore concentrate at a concentration on said concentrate between 0.001 to percent by weight of concentrate. -W fo 3-7 39 The process of any one of claims/OW to f wherein green pellets of mineral ore are obtained by agglomerating said particulate material and said green pellets are fired by a means for applying heat sufficient to indurate said -77 ore, said particulate material being taconite. The process of claimO wherein said sufficient heat to indurate said pellets is of a temperature of above 1800'F. 4,.e The process of claimf wherein said sufficient heat to indurate said pellets is of a temperature of about 2800 F. Ll A product of the process of any one of claim "3 .E qta. A process of producing pellets comprising: selecting a water-soluble poly(acrylamide) based polymer, said polymer being in the form of a dry powder; mixing a binding quantity of said polymer with a taconite concentrate; S(c) pelletizing in a balling apparatus the *0 15 mixture of step to form green pellets; and indurating said green pellets with heat. r3.. The process of claim. wherein said polymer contains repeating units selected from the group consisting of units of the formula: R 13 14 CH2 -iC- N S- R 1 wherein R 13 is a hydrogen atom or a methyl group; R 14 is a hydrogen atom, a methyl group or an ethyl group; R 15 is a hydrogen atom, a methyl group, an ethyl group or -R 1 6 -SO 3 X, wherein R 16 is a divalent hydrocarbon group having 1 to 13 carbon atoms and X is a monovalent cation; units of the formula:
5. 78- -I- H H CH2-- C CH C I I C=U C=O NH2 O f R2 d wherein R 2 is an alkali metal ion, f and g are from 5 to 90 percent, f g 100, and d is from 1,000 to 500,000. 4-2or 4-3 04.j The process of claim/n 2 Ab Awherein an inorganic salt is also mixed with the concentrate, said inorganic salt being an alkali metal or an alkaline earth metal salt of carbonates, halides, or phosphates, or a combination thereof. -4- The process of claim r wherein said inorganic salt is applied to said taconite concentrate in a concentration between 0.001 to 0.5 percent by weight and wherein said polymer is applied to said taconite concentrate at an active polymer concentration between 0.001 to 0.3 percent by weight. A product of the process of any one of claims/A40-t II F71 The process of claim AiE wherein said inorganic salt includes less than 3 lb/tonne of added Na 2 CO 3 and calcium carbonate. /I ,1 (jf The process of claim. ,wherein said inorganic salt includes less than 1.2 lb/tonne of added Na 2 CO 3 andl calcium carbonate. 4q. The process of claimW wherein the Na 2 CO 3 is added as a powder after filtration of taconite concentrate. b The process of claim J wherein the Na 2 CO 3 is added to a flux slurry before filtration of taconite concentrate. 51 he process of claima wherein said inorganic salt includes less than 3 Ib/tonne of added Na 2 CO 3 and calcium carbonate. -79- 4. The process of claim wherein said inorganic salt includes less than 1.2 lb/tonne of added Na 2 CO 3 and calcium carbonate. S3 y. The process of claim M wherein the Na 2 CO 3 is added as a powder after filtration of taconite concentrate. }S The process of claim wherein the Na 2 CO 3 is added to a flux slurry before filtration of taconite concentrate. S .57. The process of claim,a including the additional steps of selecting an inorganic material that tends to reduce the acidity of taconite concentrate and adding that material to the taconite concentrate in an amount sufficient to result in a flux pellet. The process of claimn. wherein sodium carbonate is commingled with said inorganic material selected to create the flux pellet. The process of claim iinduding the additional steps of selecting an S inorganic material that tends to reduce the acidity of taconite concentrate and 15 adding that material to the taconite concentrate in an amount sufficient to result in a flux pellet. S7 The process of claim 0 wherein sodium carbonate is commingled with said inorganic material selected to create the flux pellet. The process of claim 1 2t r substantially as hereindescribed with reference to any one of the examples. DATED this 2 day of April 1990. UNION CARBIDE CORPORATION By Their Patent Attorneys: CALLINAN LAWRIE j-VP