AU703815B2

AU703815B2 - Process for recovering iron from iron-containing material

Info

Publication number: AU703815B2
Application number: AU49200/96A
Authority: AU
Inventors: George W. Ford Jr.
Original assignee: Covol Technologies Inc
Current assignee: Boral Industries Inc
Priority date: 1995-06-06
Filing date: 1996-02-08
Publication date: 1999-04-01
Anticipated expiration: 2016-02-08
Also published as: PL323625A1; HUP9801753A2; BR9608411A; EP0831984A1; NZ303005A; CA2223044A1; EP0831984A4; WO1996039290A1; JPH11506168A; AU4920096A; KR19990022152A; TR199701542T1

Description

PROCESS FOR RECOVERING IRON FROM IRON-CONTATNING

MATERIAL

Technical Background The present invention involves the recovery of metal values from metallurgical waste materials, particularly those wastes formed in iron and steel making processes.

Background Art In the production processes of iron and steel, waste materials are formed that contain oxidized iron and frequently other oxidized metals. These are usually materials in the form of dust in the gas waste streams. This waste is difficult to process because the dust usually has a fine particle size, and merely reintroducing it into a reduction furnace to recover the iron will usually result in it becoming again a part of the waste gas stream. Accordingly, these fine particle size materials, even though they contain a substantial metal content, have been essentially worthless.

There are methods of storing and stabilizing the dust into piles near the steel-making facility, but this option is becoming increasingly unacceptable as environmental regulations become stricter and as available space becomes more restrictive because land values increase.

The dust can also be recycled and stabilized into ceramic or building materials but not necessarily on a cost effective basis. But these methods do not exploit the value of the residual iron and other metals in the waste.

A waste material of common concern is dust from electric arc furnaces, commonly referred to as EAF dust. Electric arc furnaces typically melt scrap metal through the use of high voltage electrical current. The scrap metal may come from a variety of sources, including; discarded railroad rails, cut sheet steel, discarded structural steel, and scrap tmobiles. The scrap metal is added to the electric are furnaces without separating non- 96/017 98 ferrous metals, such as lead, zinc, and cadmium. During the operation of the electric arc furnace, these non-ferrous metals are vaporized from the scrap, condensed into a dust from the waste gas stream and are deposited in a bag house. In addition to these metals, the waste gas stream deposits a large amount of recoverable iron in the bag house. Accordingly, the iron and heavy metal, usually in an oxidized form, are combined in an amorphous EAF dust with particle sizes commonly less than 20 microns. Such EAF dust is now classified as hazardous waste by the EPA due to the lead and cadmium content. As such, extensive procedures must be maintained in order to protect the environment from heavy metal contamination and meet EPA regulations. All the metals in the EAF dust have value and can be reclaimed if an efficient way of separation and reduction of the component dust can be achieved. Additionally, the EAF dust can be rendered non-toxic, if the trace heavy metals can be removed from the dust.

Several processes have been applied to this problem with differing degrees of success.

While these processes have been successful in removing heavy metals, they have been inadequate in recovering the iron, and generally leave a fine iron oxide-containing dust of no value.

The most common approach is called fuming. This process utilizes the differing boiling points of the heavy metals to obtain their separation. The dust is heated to temperatures above the boiling points of the metals being separated, causing the metals to evaporate. The evaporated metals are removed as a dust from the gas and condensed in a collection device for further processing. The boiling points of these trace metals are considerably lower than that of iron, which is the largest single component of the dust. After the lead, zinc, and cadmium are separated, the remaining dust consists primarily of iron in the form of iron oxide. Being in a dust form, this material cannot be successfully processed into iron and is left as a waste. Another problem with fuming, is that it is energy intensive, and it also produces a significant amount of its own waste dust.

Another process used to treat EAF dust is electrowinning. This process combines a leaching and precipitation operation with electrolytic deposition. The EAF dust is first dissolved in an electrolyte to solubilize the lead, zinc, and cadmium. The solution is filtered and then precipitated with a zinc powder tn capture the lead and cadmium. The resulting zinc solution is then passed through an electrochemical recovery cell to recover the zinc.

This process recovers zinc quite well, but the leaching process does not dissolve the iron oxides and zinc ferrite, which remain as waste materials that must be dried. The dried material, once again, is in the form of a fine dust with little or no value.

EAF dust has also been processed by blending with silicate materials, such as silica sand, clay, or cullet, and heated in a furnace to form a vitrified ceramic product. The ceramic is useful as an abrasive, and the EAF dust is rendered nonhazardous, but the valuable metals contained in the dust are not recovered. These metals have been processed through an expensive refining technique just to be converted into a relatively low value material in order to render them nonhazardous.

DISCLOSURE OF THE INVENTION It is, therefore, an object of the invention to provide a method for the treatment of dusts containing iron and heavy metals that recovers both the iron and the heavy metals as a usable product.

Further objects of the invention will become evident in the description below.

In brief summary, the present invention overcomes or substantially alleviates the above-identified problems of the prior art. A method for forming a solid product, in the form of briquettes, pellets, and/or as other solid objects, is provided. The resulting product comprises an iron-containing material, e.g. EAF dust, and a carbon source, e.g., coke breeze, coal fines, and/or revert materials, bound together into solid shapes, such as briquettes, to substantially prevent degradation into dust and smaller pieces. The briquettes provide a source of iron in steel and iron-making processes and carbon for reduction of the iron. Furthermore, heavy metals in the iron-containing material are also incorporated into the briquettes and during the iron-reduction process are separated by being vaporized or fumed, thereby allowing these to be recovered. This fuming method is unique in that the fuel material is first formed into a stable solid through the use of briquetting or extruding a convenient shape or a like technique, utilizing the reaction product of particulate carbon and an organic binder. The binder reaction product maintains the formed dust materials until the zinc, lead, and cadmium have evaporated, and the iron oxides have been reduced to elemental iron. This method allows all the materials contained in the EAF dust to be reclaimed in one process. The fuel for this process can be either waste coke breeze, waste coal fines, electric arc, or natural gas, depending on which provides cost advantage.

Accordingly, the present process is for recovering iron and heavy metals I from powdered iron-containing materials. These powders, from which it has been previously not possible to recover the iron values, can now be manufactured into shapes that can be utilized iron and steel manufacture. Not only is the iron recovered, but also S* any heavy metals are also recovered. Prior attempts to place carbon-containing materials, such as coke breeze, coal fines, and/or revert materials in a solid form, such as briquettes, has been largely unsuccessful because the product does not adequately bind and is unstable, disintegrating or retrogressively degrading back into small, fine particles during storage and handling prior to use. However, the present invention allows a carbon and iron containing material to be formed into a solid shape that is strong and durable enough for handling and storage, as well as sufficient to bind the shapes in an iron-reduction process to inhibit early disintegration of the shape such that they are carried out into the waste gasses as dust.

In accordance with one aspect there is provided a process of manufacturing articles from fine iron-containing material, comprising; mixing the iron-containing material, and carbon, to form a iron-containing/carbon mixture, the mixture being essentially free of oils and moisture; dissolving styrene or acrylonitrile polymer resin in a hygroscopic solvent combining the dissolved styrene or acrylonitinle polymer, the iron containing/ carbon mixture, calcium carbonate, and alumino-silicate binder; emulsifying polyvinyl polymer in water, adding the emulsion to the combination S of step and substantially homogenizing the resultant; and compressing the mixture from into articles.

i In accordance with a further aspect of there is provided a process of forming articles from

S

fine iron-containing material, comprising; the steps of: combining and mixing a fine ironcontaining material, carbon, a conditioner of dissolved styrene or acrylonitrile polymer resin in a hygroscopic solvent, and a polyvinyl acetate or polyvinyl alcohol homopolymer; compressing the resulting mixture into articles comprising a source fuel and iron-containing material from which iron is later recovered.

By "fine iron-containing materials" is meant any powdered or small particle or particulate material containing iron, iron oxides and/or other iron compounds. The powdered material may also contain other metals, including heavy metals, in any form such as in metal oxides, as well as other minerals, particularly those found in ores, waste materials from \667157.KAD mineral extraction, and the like.

A suitable iron-containing material is electric arc furnace dust (EAF dust) that is deposited from waste gas streams coming from electric arc furnaces used in iron and steel production. Other suitable iron-containing materials include other by-products from steel production, such as mill scale, precipitated iron oxide, and dust (so-called sludge), typically collected in the filter bag houses of oxygen furnaces.

o a.

*DOCS\AL\667157.KAD Sa s\ L6 7 57KA The iron-containing material is normally essentially free of moisture, with a moisture level at or below 2 wt. and is essentially free of non-mineral substances, such as oils. This can be accomplished by any suitable cleaning and drying method, preferably, by the method that is more fully described and illustrated in the examples.

The powdered material is first mixed with carbon. At this point, the iron-containing material and the carbon may be optionally reacted with a mineral acid, such as hydrochloric acid.

The carbon may be any suitable carbon, such as a metallurgical grade coke. The carbon should be fine enough and in form that allows formation of the solid articles, as discussed further below.

In addition, it should not contain impurities that would interfere materially with formation of the S article or with the subsequent iron-reduction process in which the article is used. The carbon is typically a fine powdered material.

In a typical application of the invention, the powdered material and the carbon are mixed to form a mixture of about 15 to 35 preferably about 25 wt.% of the carbon.

The mixture is then reacted with hydrochloric acid. The mixture is preferably reacted with hydrochloric acid, in an amount between 1 and 4 preferably about 2 wt.% acid, After reaction with hydrochloric acid, the iron-containing mixture is then compounded a. a S. into a mixture with binders for forming into one or more articles. The reacted mixture is mixed with calcium carbonate, an alumino-silicate binder, an organic binder, and a polyvinyl alcohol.

That may be accomplished by mixing the reacted mixture with calcium carbonate and an alumino-silicate material. The calcium carbonate acts as a hardener and also as a flux for removal of impurities during the reduction to iron phase. The alumino-silicate also functions as a hardener for the articles, and also as a flux. The alumino-silicate material may be any of such materials used in forming articles, such as kaolin clay materials, kaolinite, mixtures of alumina and silica, dolomite lime type clays, and the like.

An organic binder is mixed into the mixture with the calcium carbonate and aluminosilicate. The binder is the binder described in United States Patent No. 5,453,103, filed January 21, 1994, which disclosure is hereby incorporated by reference. This binder is made by dissolving styrene or acrylonitrile polymer resin in a hygroscopic solvent, such as methyl-ethylketone.

An emulsion made by emulsifying a polyvinyl polymer in water is added to the mixture with the styrene polymer binder. The resultant it then substantially homogenized. The polyvinyl polymer may be polyvinyl alcohol or polyvinyl acetate.

S. The homogenized mixture with the polyvinyl acetate or polyvinyl alcohol is then formed

S

into solid articles by any suitable method, such as extrusion, molding, and/or compression.

Typically, the extrusion or molding pressures on high, between about 15,000 and 45,000 psi, preferably about 30,000 psi, to produce dense, and fracture and abrasion resistant product.

BRIEF DESCRIPTION OF THE DRAWINGS o:S Figure 1 is a flow sheet illustrating an embodiment of the invention.

S.

BEST MODE FOR CARRYING OUT THE INVENTION Example 1 This example illustrates the treatment of powdered iron-containing material

(ICM)

feedstocks and culminates in the production of high-grade iron metal. Referring to Figure 1, ICM is first cleaned using a surfactant to create an emollient containing the oils and other 157.KAD contaminants found in the ICM. The 1CM is dried in a rotary kiln to vaporize the emollient and reduce the total moisture content, preferably to below about 2 although up to 6 wt.% may be used, depending upon the composition being processed.

The cleaned ICM is then weighted into a mixer along with approximately 25 wt.% metallurgical grade coke and reacted with hydrochloric acid at about 2 The ICM, coke and hydrochloric acid is then mixed for about 5 minutes.

After mixing, about 5 wt.% calcium carbonate and 2.5 wt.% Kayolite (A1 2 03 SI0 2 are added to the acid treated ICM and coke and mixed for about 5 minutes. The calcium carbonate and Kayolite act as hardeners in the ICM mixture and also as fluxes as the material *o is reduced to metal.

o•• •After mixing, about 3 wt.% of an organic binder material is added to the batch mixer and allowed to mix for approximately 5 minutes. The binder is a styrene polymer resin (10 wt.%) dissolved in a hygroscopic solvent, such as methyl-ethyl-ketone. As this binder contains a hygroscopic solvent, any water generated in the earlier reactions is driven off with the solvent.

After mixing, about 4 wt.% of a polyvinyl alcohol homopolymer is added to the mixture and allowed to mix for 10 minutes. The material is then fed into a briquetting press under high injection pressure or like machine to form an easily handled, hard article.

The formed briquettes or other solid articles are then heated to about 250 o F to 400 o F to cure. The curing process reduces the moisture content of the briquette to less than about 2 Once cured, the briquettes are introduced into an electric arc furnace where reduction of the oxides takes place. Reduction of iron oxides can take place with minimal power penalty due to the fact that the briquette continues to be held together under the slag layer by the binder until such time as the reduction reaction takes place between the coke and 157.KAD oxidized iron. The other materials added to the briquette or other solid articles acts as fluxes carrying impurities into the slag layer above the liquid metal bath.

Instead of the styrene polymer, an acrylonitrile polymer may be used. A suitable homopolymer material is 32-024 homopolymer PVA emulsion, available from National Starch and Adhesive. The acrylonitrile polymer is preferably retained in a prolonged fluid state by mehtyl-ethyl-ketone. Acrylonitrile polymer is available from Polymerland. Technical grade methyl-ethyl-ketone, available from Dice Chemical Co. and Thatcher Chemical Co., is satisfactory. Ninety percent by weight methyl-ethyl-ketone and ten percent by weight acrylonitrile polymer is suitable, although these amounts can be varied.

Examples 11 to V These examples illustrate the treatment of powdered iron-containing material

(ICM)

o: feedstocks and culminates in the production of high-grade iron metal. The general procedure for each of the examples was first to clean the ICM using a surfactant to create an emollient 00 containing the oils and other contaminants found in the ICM. The ICM is dried in a rotary kiln 0* to vaporize the emollient and reduce the total moisture content.

The cleaned ICM is then weighted into a mixer along with the particulate carbon reacted with hydrochloric acid at about 2 The ICM, particulate carbon and hydrochloric acid are then mixed for about 5 minutes.

After mixing, about 5 wt.% calcium carbonate and an alumino-silicate, 2.5 wt.% Kayolite

(AL

2 03+ SIO are added to the acid treated ICM and particulate carbon and mixed for about 5 minutes.

After mixing, about 3 wt.% of an organic binder material is added to the batch mixer and allowed to mix for approximately 5 minutes. The binder was an acrylonitrile polymer 157.KAD and was retained in a prolonged fluid state by methyl-ethyl-ketone as described above.

After mixing, about 4 wt. of a polyvinyl alcohol homopolymer, such as used in Example I, is added to the mixture and allowed to mix for 10 minutes. The material is then fed into a briquetting press under high injection pressure or using other machinery to form an easily handled, hard. solid article.

The formed briquettes or other solid articles are then heated to about 2500 to 400 0 F to cure. The curing process reduces the moisture content of the briquette to less than about 2 wt.%.

Once cured, samples of the briquettes or other solid articles were introduced into an electric arc furnace where reduction of the oxides takes place. Analyses of the starting materials, and the iron and slag products resulting from the reduction were made. The results of the tests are summarized below.

Exmple I For this Example, the particulate carbon was coke breeze (10400 BTU), and the IRM was a mixture of mill scale from a steel mill (Nucor, Plymoth, Utah), and an iron oxide precipitate from a oxygen furnace (Gulf States, Gadston, Alabama). The analysis of the Sstarting materials, the briquette produced, and the reduction products (in wt. are shown below in Table A. Of the mass of the briquette introduced into the reduction process, approximately 88% went into the iron product, and 21% into the slag (These numbers do not add exactly to 100% because of inaccuracies in measurement and round-off errors.) TABLE A BASIC IRON TESTS STARTING MATERIALS FOR

REDUCTION

FORMING BRIQUETTE

PRODUCTS

NUCOR

GULF

DESCRIPTION COKE MILL STATES BRIQ IRON

SLA

BREEZE SCALE PRECIP SAMPLE NO. 1/8-15-1 2/8-15-1 3/8-15-1 4/8-15-1 5/8-15-1 6/8-15- CARBON 63.3 0.41 6.59 18.2 3.27 SULFUR 0.54 0.03 0.12 0.22 0.12 IRON 7.

_IRON 73.4 51.1. 45.5 83.6 MANGANESE 0.54 0.26 0.316 0.131 0.

THOSPHORUS--------- °3 PHOSPHORUS 0.01 0.01 0.01 0.005 0.

SILICON 0.

SILICON 0.32 0.84 1.15 0.35 COPPER 0.206 0.061 0.088 0.194 0. -NICKEL 1-4 0.063 0.029 0.032 0.101 0 CHROME*--.--. CHROME 0.063 0.03 0.046 0.094 0.1

MOLY

MOLY** 0.005 0.015 0.00 0.004 0.( TIN 0.026 0 1 SZINC 0.0 26 0.0 0.017 0.03 0.( 0.008 0.426 0.143 0.008 0.( BORON 0.01 0.01 0.01 0.03 TITANIUM 0- TITANIM 0.002 0.022 0.025 0.002 0.1 ARSENIC 2- Example l 0.001 0.001 .J For this Example, the particulate carbon was coke breeze (10400 BTU), and the ICM was a mixture of mill scale from a steel mill, and sludge from the filters from a basic oxygen S furnace (Q-BOP) (both at Geneva, Utah). The analysis of the starting materials, the briquette produced, and the analyses of the reduction products of five reduction tests of the briquettes (in wt. are shown below in Tables B-1 and B-2. For tests 1 to 3 the results are for the slag accumulated over all three tests. The percent of the mass from the briquettes introduced into the reduction process that resulted in the iron product and the slag are shown in Table C. (These numbers do not add exactly to 100% because of inaccuracies in measurement and round-off errors.) 11 IPEA/ 1999 TABLE B-1 BASIC IRON TESTS STARTING MATERIALS FOR FORMING REDUCTION

PRODUCTS

BRIQUETTE

DESCRIPTION

BRIQ

GENEVA GENEVA TEST 1 TEST 2 TEST 3 TEST 1-3 MILL SLUDGE IRON IRON IRON SLAG

SCALE

SAMPLE/TEST# 11/8-16-2 12/8-16-2 13/8-16- 14/8-16- 15/8-16- 16/8-17- 17/8-17-4 2 2 3 4 C" A Dm 2.28 SULFUR 0.07 IRON 69.3 MANGANESE 0.596 PHOSPHORUS 0.01 SILICON 0.01 COPPER 0.087 NICKEL 0.032 CHROME 0.042 MOLY 0.003 TIN 0.003 ZINC 0.015 BORON 0.01 TITANIUM 0.003 ARSENIC 0.003

ALUMINUM

MAGNESIUM

LEAD

CADMIUM

19.4 0.28 41.5 0.083 0.084 0.014 0.01 0.001 0.01 0.01 0.034 0.35 0.25 0.034 0.003 7.35 1.85 2.21 0.09 0.08 0.06 57.5 93.2 96 0.475 0.3 0.024 0.007 0.007 0.008 8 0.06 0.01 0.007 0.063 0.009 0.008 0.069 0.011 0.01 0.89 0.021 0.01 0.014 0.012 0.007 0.004 0.001 0.036 0.013 0.005 0.26 0.01 0.01 0.007 0.004 0.001 0.003 0.03 0.003 1.61 0.15 0.07 0.28 97 1.22 0.081 0.94 0.005 0.011 0.21 0.01 0.031 0.003 0.022 0.003 0.0119 0.002 0.157 0.01 0.001 0.29 0.007 0.005 0.01 1.45 0.001 0.29 0.003 0.003 18.4 6.64 3.77 0.01

'I

BASI4 PCT/US 9 6/0179 8 i'pLA 6 AUG 1996 'ABLE B-2 SIRON

TESTS

REDUCTION

PRODUCTS

EUT'*

TEST 4 TEST 4 TEST 5 TEST IRON SLAG IRON

SLAG

/8 6 1/817-5 19/8-17-5 20/8-21-6 2/-21-6 7.35 2.34 0.16 2.39 0.26 0.09 0.06 0.37 0.07 0.33 57.5 86.1 1.5 89.6 0.75 0.475 0.446 1.2 0.175 0.678 0.007 0.09 0.017 0.01 0.003 8 0.05 0.01 0.193 23.5 0.007 0.04 0.002 0.036 0.014 0.008 0.043 0.003 0.027 0.001 0.01 0.064 0.01 0.029 0.001 0.01 0.003 0.003 0.01 0.01 0.007 0.058 0.251 0.03 0.01 0.036 0.014 0.002 0.006 0.005 0.26 0.01 1.56 0.01 1.53 0.007 0.058 0.251 0.046 0.357 0.003 0.003 0.003 005 005 3N PRODUCTS IRON

SLAG

96.594 4.667 98 .385 99.2 199 89.379 5.342 9263 27.4548 13

TA

REDUCTI4 v-,EZ-DS1Et

I

Example IV For this Example, the particulate carbon was coke breeze (10400 BTU), and the Irct was a mixture of iron ore from the Geneva mine near Cedar City, Utah, and sludge from the filters from a basic oxygen furnace (Q-BOP) (Geneva Steel, Geneva, Utah). The analysis of the starting materials, the briquette produced, and the analyses of the reduction products of five reduction tests of the briquettes (in wt. are shown below in Table D. Of the mass from the briquettes introduced into the reduction process about 88.9% ended up in the iron product and 22.1% ended up in the slag product for Test 1. (These numbers do not add to 100% exactly because of inaccuracies in measurement and round-off errors.) This data was not obtained for Test 2.

too.

0 .:90 a a.

toa to:n a a: a.

a *a.

.a

DESCRIPTION

SAMPLE#

TABLE D BASIC IRON TESTS STARTING MATERIALS FOR FORMING BRIQUETTE REDUCTION PRODUCTS

BRIQ

RED SEA CEDAR TEST I TEST 1 TEST 2 TEST 2 SLUDGE ORE IRON SLAG IRON

SLAG

24/8-21-8 25/8-21-8 26/8-21-8 22/8-21-7 23/8-21-7 27/8-21-8 28/8-21-8

CARBON

SULFUR

IRON

MANGANESE

PHOSPHORUS

SILICON

COPPER

NICKEL

CHROME

MOLY

TIN

ZINC

BORON

TITANIUM

ARSENIC

r 0.82 0.1 46.1 0.319 0.012 1.96 0.052 0.011 0.03 0.01 0.02 0.386 0.01 0.02 0.005 0.24 0.06 46.4 0.058 0.06 3.11 0.001 0.028 21.6 0.19 33.9 0.113 0.033 6.5 0.015 0.014 2.29 0.05 86 0.2 0.008 0.229 0.024 0.025 0.033 0.01 0.03 0.006 0.01 0.033 0.005 0.86 0.47 2.25 0.897 0.013 15.7 0.002 0.001 0.01 0.01 0.01 0.005 1.67 0.228 0.005 2.69 0.01 40.5 0.084 0.03 0.515 0.017 0.025 0.03 0.01 0.01 0.005 0.05 0.046 0.005 10.7 2.93 0.013 0.01 3.6 0.006 0.004 0.005 0.01 0.01 0.005 0.06 0.021 0.005 0.006 0.001 0.01 0.01 0.02 0.01 0.012 0.142 0.01 0.01 0.005 0.018 0.005 0.005 Example V For this Example, the particulate carbon was coke breeze (10400 BTU), and the Icm was ferric oxide dust derived as a byproduct form photographic film production. The analysis of different batches starting materials, and a cumulative analysis of the iron reduction products (in wt. are shown below in Table E.

a.

a. p

DESCRIPTION

TEST#

CARBON

SULFUR

IRON

MANGANESE

PHOSPHORUS

SILICON

COPPER

NICKEL

CHROME

MOLYBDENUM

TIN

ZINC

TITANIUM

Example VI TABLE E BASIC IRON TESTS STARTING IRON MATERIALS FOR FORMING

BRIQUETTE

KMFE203 KMFE203 KMFE203 KMFE203 DUST DUST DUST

DUST

29.00 30.00 29.00 30.00

I

0.030 0.020 60.500 2.270 0.003 0.570 0.001 0.007 0.048 0.010 0.010 0.067 0.027 r I 0.030 0.025 63.600 2.280 0.003 0.610 0.001 0.006 0.047 0.010 0.020 0.068 0.030 0.030 0.020 60.500 2.270 0.003 0.570 0.001 0.007 0.048 0.010 0.010 0.067 0.027 0.030 0.025 63.600 2.280 0.003 0.610 0.001 0.006 0.047 0.010 0.020 0.068 0.030 3.020 0.022 88.200 0.200 0.032 0.330 0.514 0.114 0.275 0.090 0.030 0.013 0.015

IRON

PRODUCT

KMFE203 L 31.00 For this Example, the particulate carbon were coal fines, and the IctK was the same as in Example III. The analysis of the iron and slag reduction products (in wt. are shown below in Table F.

PCT/US 9 6 017 9 8 iPEA/u TABLE F BASIC IRON TESTS SLAG

IRON

DESCRIPTION PRODUCT

PRODUCT

FROM COAL FROM COAL SAMPLE/TEST# 33/9-21-37 34/9-21-37 CARBON 3.29 2.74 SULFUR 0.02 1.05 IRON 14.03 89.10 MANGANESE 0.22 0.55 PHOSPHORUS 0.02 0.01 SILICON 7.38 1.65 COPPER 0.00 0.45 NICKEL 0.01 0.06 CHROME 0.03 0.12 MOLYBDENUM 0.01 0.01 TIN 0.01 0.04 ZINC 0.01 0.01 TITANIUM 0.07 0.05 Theory It is believed that the present invention polymerizes the carbon particles contained in the carbon source into a new long chain polymer compound, yet unidentified, which provides structurally superior strength of the shapes. It is known that oxides of carbon will hydrolyze in water. This reaction leaves free carboxyl ions present in the compound.

Introduction of the doped methyl-ethyl-ketone is believed to allow for attachment of the styrene polymer to the free carbon ions by exchange of the polymer for water which is absorbed into the solvent.

In the next phase, polyvinyl acetate is introduced. Again the presence of the methylethyl-ketone acts as a catalyst to remove and allow the acrylonitrile or styrene to react to the polyvinyl acetate.

The resulting compressed shapes, such as briquettes, pellets, and/or extruded solid pieces are structurally stable and do not retrogress into fine particles during storage and handling.

While this invention has been described with reference to certain specific embodiments and examples, it will be recognized by those skilled in the art that many variations are possible without departing from the scope and spirit of this invention, and that the invention, as described by the claims, is intended to cover all changes and modifications of the invention which do not depart from the spirit of the invention.

Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising" or the term "includes" or variations thereof, will be understood to imply the inclusion of a stated element or integer or group of elements or integers but not the exclusion of any other element or integer or group of elements or integers. In this regard, in construing the claim scope, an embodiment where one or more features is added to any of the claims is to be regarded as within the scope of the invention given that the essential features of the invention as claimed are included in such an

O.*

o embodiment.

7 17 ooo• oo o ooO oo o• oo ~17

Claims

1. A process for manufacturing articles from fine iron containing material, the process comprising: mixing the iron-containing material, and carbon, to form an iron- containing/carbon mixture, the mixture being essentially free of oils and moisture; dissolving styrene or acrylonitrile polymer in a hygroscopic solvent; combining the dissolved styrene or acrylonitrile polymer, the iron- containing/carbon mixture, calcium carbonate, and an alumino-silicate binder; emulsifying polyvinyl polymer in water, adding the emulsion to the combination of step and substantially homogenizing the resultant; and compressing the resultant from into articles.

2. The process of Claim 1 wherein the polyvinyl polymer is poly vinyl 1.

3. The process of Claim I wherein the polyvinyl polymer is poly vinyl alcoho S. acetate.

4. The process of Claim 1 wherein hydrochloric acid is added during the 20 mixing of the iron-containing mixture and carbon in

5. The process of Claim 1 wherein the resultant in is compressed into shape articles in a briquetting press.

6. The process of Claim I wherein the resultant in is compressed into articles through extrusion.

7. The process of Claim 1 additionally comprising the step of heating the articles to remove moisture from the articles.

8. The process of Claim 1 additionally comprising introducing the articles into a reaction environment for reduction of the iron in the articles.

9. The process of Claim I wherein the iron-containing material contains heavy metals and the articles are introduced into a furnace for evaporation of the heavy metals and for reduction of the iron. The process of Claim 1 wherein the iron-containing material is treated before step by mixing the iron-containing material with a surfactant to disengage non-mineral substances and form an emollient substance comprising surfactant and the non-minerals, and drying the emollient substance to reduce the moisture content thereof by vaporization.

11. A process according to Claim 1 wherein the articles are compressed at a pressure of about 30,000 psi.

12. The process according to Claim 1 wherein the hygroscopic solvent comprises methyl ethyl ketone. 20

13. A process for manufacturing shaped articles from fine iron-bearing material, the process comprising: mixing the iron-bearing material, and carbon, to form an iron- bearing/carbon mixture, the mixture being essentially free of oils and moisture; dissolving acrylonitrile polymer in a hygroscopic solvent; 25 combining the dissolved acrylonitrile resin, the iron-bearing/carbon mixture, calcium carbonate, and an alumino-silicate binder; emulsifying polyvinyl polymer in water, adding the emulsion to the combination of step and substantially homogenizing the resultant; and compressing the resultant from into shape articles.

14. A process of forming articles from fine iron-containing material comprising the steps of: combining and mixing a fine iron-containing material, carbon, a conditioner of dissolved styrene or acrylonitrile polymer resin in a hygroscopic solvent, and a polyvinyl acetate or polyvinyl alcohol homopolymer; compressing the resulting mixture into articles comprising a source fuel and iron- containing material from which iron is later recovered. A process according to Claim 14 wherein the carbon comprises coal. DATED this 26th day of November 1997 o t COVOL TECHNOLOGIES, INC. By Its Patent Attorneys DAVIES COLLISON CAVE q C e

157.KAD