SU1538902A3 - Method of nodulizing iron-ore material - Google Patents

Abstract

This invention is a method for agglomerating mineral ore concentrate comprising the commingling of mineral ore concentrate with a binding amount of a water soluble, high molecular weight polymer. The selected polymer is applied to the mineral ore concentrate either (1) dispersed in a water-in-oil emulsion or (2) as a dry powder. The most preferred polymers are water soluble poly(acrylamide) based polymers.

Description

The invention relates to the preparation of iron ore materials for metallurgical processing, mainly for the production of iron ore burned pellets, and can be used in the preparation of raw iron ore pellets using water-soluble polyacrylamide-based polymers as a binder.

The purpose of the invention is to improve the quality of raw granules.

Water soluble high molecular weight polymers are used as a binder in the preparation of raw granules of iron ore material in an amount of 0.001-0.3 wt.% Of iron ore material. These polymers are applied to iron ore in

and

as a dry powder or as a water in oil emulsion.

Polymers include water-soluble homopolymers, copolymers, terpolymers, and quadruple copolymers. In a water-in-oil emulsion system, a selected polymer is obtained from the polymerization process of the corresponding monomer in an emulsion of water-in-oil starting materials. The polymers can be anionic, cationic, amphoteric or non-ionic. It is desirable to use high molecular weight polymers that have a high characteristic viscosity. Polymers suitable for the invention include synthetic vinyl polymers and other polymers that differ from derivatives of natural cellulose products, such as carboxymethylcellulose, hydroxymethylcellulose, as well as other pro-derived cellulose.

Water-soluble polymers include polyacrylamide-based polymers, as well as those polymers that polymerize by adding acrylic or vinyl monomers to a solution containing

free radicals. Typically, such polymers contain ionic functional groups, such as a carbonyl group, a sulfamide group, or quaternary ammonium

5 groups. The polymers can be obtained from unsaturated monomers having ethylene-type double bonds, including acrylamide, acrylic acid and methacrylamide.

0 You can also use alkali metal salts or ammonium salts of these polymers. P Polymers have the following general formula

- CH-zg

R, R and R, are independently of each other a hydrogen atom or a methyl radical;

Rt is an alkali metal ion, such as potassium ion K + or sodium

R4 is a -OR5 group, where Rj-Cj is an alkyl group or a group

ABOUT

II

-C-Q-R6,

 - an alkyl group, or

ABOUT

II

-C-C-F {"7

R7 - metal or butyl pa, phenyl radical or 35,

i

 substituted phenyl radical, either

group-CN or group

where a lies within 5-90%, preferably within JO-60%, b lies within 5-90%, preferably within 30-60%, with lies within 20%, provided that + b + with 100%, ad is an integer lying within

YuOO-500000.

Under certain conditions, alkrxyl or acyloxy groups in the polymer may be partially hydrolyzed to the corresponding alcohol groups, resulting in a four-copolymer of the following general formula

where R + is -OR5 group or group

-0-C-R7

about

where RЈ is an alkali metal ion, for example sodium ion On or K +, af lies in the range of 5-90%, preferably in the range of 30-60%, g lies in the range of 5-90%, preferably in the range of 30-60% with provided

where RЈ is sodium ion Na or potassium ion K% R is a methyl, ethyl or butyl radical, af lies in the range 5-90%, preferably in the range 30-60%, g lies in the range 5-90%, preferably within

Other polymers soluble in water include polymers obtained by homopolymerization and co-polymerization of one or more polymers.

where c lies in the range of 0.2–20%, and e, lies in the range of 0.1–20%.

Preferred copolymers of the following general formula

that f + g is 100%, a d is an integer in the range of 1000-5000000.

thirty

Preferred ternary copolymers of the following general formula

30-60%, h lies in the range of 0.2-20%, 40, provided that f + g + h is 100%.

Preferred quadruple copolymers of the following formula

45

the numbers of the following water-soluble monomers: acrylic and methacrylic acid, acrylic or methacrylic acid salts of the general formula

R8 O

1 ° II

CH2 C-O-04R9

where R8 is a hydrogen atom or a methyl group, a Rg is a hydrogen atom, an alkali metal atom (e.g., sodium or potassium), an ammonium group, a substituted ammonium group of the general formula

UjlR ,, I U ,, l

neither

where R) 0, R and K, 2 are independently selected from a series consisting of a hydrogen atom and alkyl groups containing 1-18 carbon atoms (it may be necessary to control the number and length of groups with a long alkyl chain in order to to ensure that the monomer is water soluble). For example, alkyl groups containing 1 to 3 carbon atoms, aromatic groups, for example a benzyl group, or oxyalkyl groups containing 1 to 3 carbon atoms, for example, a triethyolamine group, or mixtures thereof; acrylamide and methacrylamide and their derivatives, including acrylamide and methacrylamide monomers of the general formula

m

CIS cc14 RIS

where K) d is a hydrogen atom or a methyl group, a hydrogen atom or a methyl or ethyl group, R15 is a hydrogen atom, a methyl group, an ethyl group or a group of the general formula -R) 4S05X, where R, g is a divalent alkylene, phenylene or a cycloalkylene hydrocarbon group, containing 1-13 carbon atoms, and preferably an alkylene group containing 2-8 carbon atoms, a cycloalkylene group containing 6-8 carbon atoms, or a phenylene group, and most preferably the group is (XCHj -CHi,

o

-sn (sna)

-O-9CH3

X is a monovalent cation, for example, a hydrogen atom, an alkali metal atom

0

thallium (e.g., potassium or sodium atom), ammonium group or substituted ammonium group of general formula

/ R, T / / R, a / / R, g / NH. where R, T, R, e, R, 9 are independently selected from each other amongst a row consisting of a hydrogen atom, an alkyl group containing 1-18 carbon atoms (it may be necessary to control the number and chain length of groups with a long alkyl chain to ensure that the monomer is water soluble), for example, alkyl groups containing 1–3 carbon atoms, aromatic groups, such as a benzyl group, or oxyalkyl groups containing 1–3 carbon atoms, for example, three ethanolamine groups , or mixtures thereof, and similar ones Connections

Inorganic salts in an amount of 0.001-0.5 wt.% May be additionally added to the iron ore concentrate before processing it in the granulating drum, mainly in order to increase the compressive strength of the granules in the dry state. Inorganic salts can be added both before, and after or during the process of adding dry or emulsified polymer. Polymers with ssami on their own, in the absence of inorganic salts,

5 increases the strength of dry granules during compression tests, but not to the same extent as inorganic salts.

The inorganic salts suitable for use include the following alkali metal salts: carbonates, halides or phosphates, as well as alkalis. As specific examples of inorganic salts can

5 lead sodium carbonate, calcium carbonate CaС03, sodium metaphosphate () n, where n has a value of 2 or more, sodium chloride (NaCl), and mixtures of the indicated soils. To improve the strength of the granules during compression tests, other inorganic salts may be added. In addition, inorganic salts may be added in the form of

5 mixtures with each other in the form of powders or emulsions. As the concentration of the inorganic salt in the mineral ore concentrate increases, so does the mechanical strength.

compression of the resulting granules.

Preferred hydrophobic liquids that are used in these emulsion systems are paraffinic hydrocarbons of iso-structure. As an example of paraffinic hydrocarbons of iso-structure suitable for carrying out the process, one can cite the product supplied by Exxon Corporation (trade designation Isopar M). Other hydrophobic liquids used as an external phase in emulsion systems include benzene, xylene, toluene, mineral oils, kerosene, petroleum, paraffinic hydrocarbons, and mixtures of these liquids.

In the case of the most preferred embodiment of the method, which involves the use of a polymer binder system in the form of a water-in-oil emulsion, for

water in oil oil in water as a result

like it

emulsions use two surfactants. The first surfactant is used to form a water-in-oil emulsion system. After the formation of a water-in-oil emulsion, a second surface-active agent is added. The second surface active agent is a water soluble emulsion reversing agent, which obviously allows the emulsion to be reversed.

in an emulsion such as contacting it with natural moisture contained in iron ore concentrate, or with moisture added to said concentrate. When a water-in-oil emulsion is formed, the polymer is withdrawn from the internal aqueous phase and appears on the surface of the iron ore concentrate. A similar appearance of the polymer on the surface of the iron ore concentrate makes it possible to quickly bind the polymer to the concentrate. Emulsions that do not contain reversing surfactants can also be used.

I

Surface-active agents suitable for use in the preparation of emulsions are usually oil-soluble agents having a hydrophilic-lyo value.

38902Y

total balance (HLB) in the range of 1-10, and preferably in the range of 2-6. Such surface active agents are commonly referred to as water in oil agents. Suitable surface-active agents include esters of acids, for example, sorbitan monolaurate, sorbitan, tan monostearate, sorbitan monooleate, sorbitan trioleate, mono- and diglycerides, for example mono- and diglycerides, obtained from glycerolysis of edible fat, polyoxyethyl, 15%, , for example (4) polyoxyethylated sorbitan-ostearate, polyoxyethylated linear alcohols, for example Terpitol 15-S-3 and Tergitol-25-L-3,

20 supplied by Union Carbide Corporation; polyoxyethylene sorbitol esters, for example polyoxyethylene sorbitol derivatives of beeswax, polyoxyethylene

25 alcohols, for example (2) -polyoxyethyl cetyl ether, as well as similar listed substances.

0

five

0

five

0

five

The water-soluble emulsion-reversing surfactants that can be used include polyoxyethylene alkylphenol, polyoxyethylene (10) cetyl ether, polyoxyethylene alkyl aromatic esters, quaternary ammonium derivatives, sodium oleate, M-cetyl-H-ethylmoline, ethoxylate sodium lauryl sulfate; condensation products of heavy fatty acids with ethylene oxide, for example, the reaction products of oleic alcohol with 10 units of ethylene oxide; condensation products of alkylphenols and ethylene oxide, for example, the products of the reaction of isooctylphenol with 12 units of ethylene oxide; condensation products of heavy fatty amines with 5 or more ethylene oxide units; ethylene oxide condensation products with partial esters of heavy fatty acid polyhydroalcohol, as well as their internal anhydrides (mannitic anhydride, called mannitane, and sorbitol anhydride, called sorbitan). Preferred surface active agents are ethoxylated nonyl phenols, ethoxylated phenol formaldehyde resins, and similar compounds.

The advantages of using a water-in-oil emulsion in preparing granules are that the amount of water added to the iron ore concentrate is significantly reduced compared to the amount required to introduce the polymer as an aqueous solution, which in turn leads to energy savings. when firing pellets. Similarly, a hydrophobic liquid or oil in a water-in-oil reversed emulsion requires some energy in the firing operation. Burning out oil droplets from the inside of the granules increases the porosity of the granules in much the same way as it does when the organic binder or polymer burns in the | inside of the granules. Similar (an increase in porosity improves the release of water vapor from the granules and reduces the degree of exposure to a sharp increase in temperature during the firing process of the granules.

Additional advantages that are achieved when using a mineral ore to introduce a polymeric binder into a concentrate during the granulation operation of a water-in-oil emulsion system are for reducing the contact time required for sufficient mixing of the polymeric binder with the iron ore concentrate. The contact time of the polymer after the emulsion is sprayed onto the iron ore concentrate should only be sufficient to activate the polymer on the surface of the iron ore concentrate. The contact burden may vary depending on the emulsion system used and on the concentration of the polymer binder in the emulsion system. As well as on the total amount of polymer binder sprayed onto the concentrate. In a preferred embodiment of the method according to the present invention, a sufficient time Necessary for mixing the polymer binder system with iron ore concentrate, is achieved by spraying a water-oil-oil emulsion onto an iron ore concentrate immediately before It is a place where the concentrate enters the granulating drum.

Applying water type emulsion

The oil to the concentrate of mineral ore at the place of its processing is effected by spraying the emulsion onto the ore concentrate by means of any conventional spraying apparatus. Inorganic salts are sprayed through the vibro-bunker or by means of other dispersing agents onto the surface of the iron ore concentrate and the resulting com position is transported along a conveyor in the direction of the granulating drum. Alternatively, the salt can be supplied in the form of aqueous solutions containing 5-40% of solid product, depending on the solubility of the inorganic salt. The polymer is activated on the surface of the iron ore concentrate quickly and, since the polymers are evenly sprayed or mixed with the iron ore concentrate, the time required for achieving a degree of mixing sufficient for the formation of granules is approximately one to one

0 minute or less.

The invention also includes the use of a binder polymer system in the form of dry minerals for treating a concentrate of mineral ore.

5 RoshkoS In this embodiment of the process, dry powdered polymers are mixed together and optionally with a dry inorganic salt. The resulting powder composition is sprayed onto the surface of the iron ore concentrate as the concentrate enters the conveyor and the powder is mixed in the granulating drum.

5 with an iron ore center. After a sufficient contact time with moisture contained in the iron ore concentrate, the polymers adsorb to the surface.

n concentrate. The corresponding contact time can be quite short, but often it lies from 1 minute to 3 hours or more. Further mixing

5 occurs within the granulating drum. Using the proposed method with the use of a dry polymer powder eliminates the need for emulsion spitting equipment. The invention also includes applying powdered binders to a concentrate of iron ore together with applying an inorganic salt in the form of an aqueous solution.

Claims (12)

1. The method of pelletizing iron ore material, including mixing the specified material with water-soluble polymers based on poly- - CHO-C - - R: R4 where R, R and R3 are independently from each other a hydrogen atom or a methyl radical; alkali metal ion, e.g. sodium ion N3 or potassium - group -OR5, where R5 is a Cj-alkyl group, or a group of the general formula ABOUT and -00-R6 where Rfe-C6 is an alkyl group, or a group of the general formula -0-C-RT, where RT is a methyl or butyl group, a phenyl radical, or substituted where R4 is a -OR5 group or a group ABOUT II -C-C-R7 where c lies in the range of 0.2-20%, and lies in the range of 0.1-20%. acrylamide, pelletization of the mixture to produce raw granules and their strengthening roasting, characterized in that, in order to improve the quality of the raw granules, these polymers in an amount of 0.001-0.3 wt.% of the iron ore material are applied to the material as a dry powder or at water-in-oil emulsion. i 2. The method according to claim 1, characterized in that the polymers have the following general formula Jb d phenyl radical, or group CN, 25. either group where a lies within 5-90%, pre-, respectfully within 30-60%, b lies within 5-90%, preferably. but in the range of 30-60%, c lies in the range of up to 20%, provided that the sum of a + b + s is 100%, a d is an integer between 1000-500000. 3. The method according to claim 2,. O. Tl and h and-y and with the fact that the polymers are quadruple copolymers of the following general formula I 4. A method according to claim 3, characterized in that the polymers consist of monomer units of acrylamide, sodium acrylate, vinyl acetate-jTara, and mixtures of the indicated monomers. 5. A method according to claim. Characterized in that the polymer consists of monomeric acrylamide and methacrylamide units and their derivatives of the general formula SNGY Rk a hydrogen atom or a methyl group; where r about R + is a hydrogen atom, methyl R five where r sixteen a group or an ethyl group;  hydrogen, methyl group, ethyl group, or group -R #, - bivalent hydrocarbon group with C., - C13, X is a monovalent cation. 20 6. The method according to claim 1, characterized in that, in order to save polymers, inorganic material is added to the iron ore material. salt. .25 7. Method pop. 6, which is different from the fact that the inorganic salt is added in an amount of 0.001-0.5 wt.%. 0 8. Method according to paragraphs. 6 and 7, characterized in that the inorganic salt is added as an aqueous solution. 9. The method according to claim 8, characterized in that the inorganic salt is an alkali or carbonates, halides and phosphates of alkali metals. 10. The method according to claim 9, wherein the inorganic salt is sodium carbonate, calcium carbonate, sodium chloride, sodium metaphosphate, and mixtures of these salts. u ny water 11. The method according to claim 1, which differs by the fact that the emulsion type in oil, it contains benzene, xylene, toluene, mineral oils, kerosene, paraffin hydrocarbons, petroleum products, isopair hydrocarbons or mixtures of these products in the form of an oil phase. 12. The method according to claim 1, wherein the emulsion contains a surface-active agent reversing it.