WO2005059038A1 - Procede de separation hydrometallurgique de poussieres de four electrique a arc (eaf) d'acierie et pigments ainsi obtenus - Google Patents

Procede de separation hydrometallurgique de poussieres de four electrique a arc (eaf) d'acierie et pigments ainsi obtenus Download PDF

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WO2005059038A1
WO2005059038A1 PCT/CA2004/002147 CA2004002147W WO2005059038A1 WO 2005059038 A1 WO2005059038 A1 WO 2005059038A1 CA 2004002147 W CA2004002147 W CA 2004002147W WO 2005059038 A1 WO2005059038 A1 WO 2005059038A1
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fraction
ferrite
pigments
magnetite
process according
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PCT/CA2004/002147
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English (en)
Inventor
Maurice Morency
Guoji Shan
Denise Fontaine
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Ferrinov Inc.
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Priority to MXPA06006918A priority Critical patent/MXPA06006918A/es
Priority to DE112004002509T priority patent/DE112004002509T5/de
Priority to BRPI0417201-9A priority patent/BRPI0417201A/pt
Priority to CA 2549070 priority patent/CA2549070A1/fr
Priority to US10/583,183 priority patent/US20070214912A1/en
Publication of WO2005059038A1 publication Critical patent/WO2005059038A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/006—Wet processes
    • C22B7/008—Wet processes by an alkaline or ammoniacal leaching
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
    • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/22—Compounds of iron
    • C09C1/24—Oxides of iron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/02—Working-up flue dust
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/30—Three-dimensional structures
    • C01P2002/32—Three-dimensional structures spinel-type (AB2O4)
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/50—Agglomerated particles
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/42—Magnetic properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the present invention relates generally to the field of steel mill dust treatment. More particularly, the invention comprises a hydrometallurgical separation process of dust produced by electric arc furnaces in steel mills. This process permits, on one hand, the decontamination of the dust and on the other hand, the production of ferrite and/or magnetite pigments useful in paints, plastics and concrete. The invention also comprises the pigments produced from this process.
  • Electric arc furnace (EAF) dust also known under the name of (K061), is classified as a dangerous material because it contains high concentrations of soluble heavy metals such as cadmium, zinc, chromium and lead, but in particular lead. More specifically, EAF dust usually contains more than 5 ppm soluble lead and hence, does not meet the limits of lead specified by TCLP (Toxicity Characteristic Leading Prodecure). This dust also contains spinel compounds, notably magnetite (Fe 3 O 4 ) and diverse ferrites (MO 2 Fe 2 O 3 ). These spinel compounds as well as contaminants appear in the form of agglomerates and aggregates.
  • the dust is brown and an observer, even with the aid of a magnifying glass, will not notice the presence of black balls of magnetite, even if certain black balls can attain 150 ⁇ m in diameter.
  • the brown ferrite contained in the dust is ultrafine, and as a pigment, coats by adsorption the larger particles of magnetite.
  • Table 1 shows the typical chemical composition of EAF dust coming from two distinct steel mills. These compositions show elevated concentrations of certain heavy metals. TABLE 1
  • EP 0 853 648 (equivalent to US 6,022,406), which describes a hydrometallurgical process of EAF dust treatment with the aim to produce pigments.
  • This process comprises a step of magnetic separation of the dust into two fractions, one fraction containing less magnetic elements, and the other fraction containing non magnetic elements, as well as treatment steps of these two fractions to obtain zinc ferrite pigments.
  • the process disclosed also has as an effect to attack the cristallographic structure of spinels other than the zinc ferrite spinel, and in this sense, is also an aggressive process.
  • One objective of the invention is to propose a treatment process of EAF dust that responds to this need.
  • that objective is accomplished with a hydrometallurgical process for the treatment of steel mill electric arc furnace (EAF) dust containing agglomerates of small ferrite particles and larger magnetite particles, the ferrite particles coating by adsorption the larger magnetite particles, the dust further containing calcium oxide, zinc oxide and a toxic amount of leachable lead together with minor elements selected from the group consisting of Mg, Cr, Cu, Cd, V, and chlorides.
  • EAF steel mill electric arc furnace
  • step b) decanting the solution of step a) to obtain a supernatant liquid containing the dissolved salts, metals and simple oxides, and a slurry containing ferrites and magnetites, a non toxic amount of leachable lead and a reduced amount of calcium; c) separating the slurry and the supernatant liquid;
  • step d) adding to the slurry obtained in step c) an anionic surfactant to disperse the ferrite particles adsorbed on the magnetite particles;
  • step d) treating the slurry from step d) to produce pigments selected from the group consisting of ferrite pigments, magnetite pigments and ferrite/magnetite pigments.
  • the sequence of steps a) to c) is performed more than one time before adding the anionic surfactant.
  • Steps a) to c) also enable the decontamination of the dust by leaching salts, metals and simple oxides such as lead oxide.
  • This selective solubilization is due to the alcaline pH solution, which is preferably greater than 12, resulting from the first washing, and optional second washing, with water.
  • This alcalinity promotes the solubilization of PbO and, with the addition of surfactant, enables the product to pass the test set out by the TCLP, which regulates standards of dangerous materials.
  • the process of the invention also enables the separation of the ferrites from the magnetites without breaking the cristallographic structure of the spinels, so as to produce magnetite and/or ferrite pigments of different grades, whose different compositions have commercial values.
  • the process also permits the decontamination of EAF dust by hydrometallurgical means while maintaining the most stable families of spinels intact.
  • the solution obtained is step a) described above has a positive zeta potential, and the anionic surfactant is preferably added in a concentration sufficient to reduce the zeta potential to or close to the isoelectric point, and more preferably to the isoelectric point.
  • the anionic surfactant is preferably a phosphate or an equivalent thereof. More preferably, sodium metaphosphate is used as the surfactant.
  • sodium metaphosphate presents the following additional advantages to the process.
  • Sodium metaphosphate converts the calcium and calcium hydroxydes present in the liquid phase into a calcium phosphate which is precipitated with the solid. Therefore, this form of calcium sequestering allows for a quicker and sharper fractionation of the slurry by, for example, a drum magnet, and in addition when the slurry is eventually separated by screening, clogging of the mesh opening is minimized, and therefore requires less cleaning.
  • Step e) of treating the slurry preferably comprises the step of magnetically separating the slurry into a first fraction composed essentially of brownish ferrites and a second fraction composed essentially of black magnetite, the first fraction being less magnetic than the second fraction.
  • the magnetic separation is preferably performed with a magnetic field in the range of 400 to 700 gauss, more preferably around 550 gauss.
  • the process further comprises steps of treating the first fraction to produce ferrite pigments and/or treating the second fraction to produce magnetite pigments.
  • the step of treating the first fraction preferably comprises the steps of:
  • the solvent is water and the ferrite pigments obtained are ferrite pigments of a first grade.
  • the solvent is sulphuric acid
  • the leaching is performed at a pH of 0,5 to 3
  • the ferrite pigments obtained are ferrite pigments of a second grade.
  • the solvent is nitric acid
  • the leaching is performed at a pH of up to 3
  • the ferrite pigments obtained are ferrite pigments of a third grade.
  • the process further comprises the step of wet grinding the solid fraction to obtain a fourth grade of pigments having a finer mean grain size and a lower concentration of lead as compared to the ferrite of the third grade.
  • the step of treating the second fraction preferably comprises the step of screening at 6 ⁇ m to obtain a first finer fraction with particles having a grain size of 6 ⁇ m or less, and a coarser fraction with particles having a grain size greater than 6 ⁇ m.
  • the process preferably further comprises the steps of: milling the coarser fraction, and removing from the milled coarser fraction the particles having a grain size greater than 40 ⁇ m and returning these particles for further milling, and a second finer fraction having particles with a grain size of less than 6 ⁇ m, resulting in the coarser fraction containing particles having a grain size between 40 and 6 ⁇ m.
  • the coarser fraction is preferably wet grinded by attrition to attain a mean grain size of approximately 0,3 ⁇ m.
  • the grinded product is thereafter filtered and dried to obtain a magnetite pigment of a first grade.
  • the first and second finer fractions which contain particles of less than 6 ⁇ m, are purified by suspending residual contaminants contained therein with an anionic surfactant, to obtain a purified magnetic fraction.
  • the purified fraction is thereafter decanted, wet grinded by attrition, filtered and dried, to obtain a magnetite pigment of a second grade.
  • the process preferably comprises the steps of:
  • step d removing from the slurry obtained in step d), particles having a grain size of 60 ⁇ m or less, to obtain a refined slurry;
  • the pigments obtained with this variant are suitable for use in concrete formulation for retarding the setting of concrete or for coloring the same.
  • the present invention also concerns ferrite pigments and/or magnetite pigments or a mixture thereof, obtained by the processes described above. It also concerns a ferrite pigment from EAF dust, showing a resistance to leaching; and preferably showing a color thermal stability at temperatures of 300°C and higher.
  • the ferrite pigment provides anticorrosion properties to metallic paint formulation.
  • the present invention also concerns the use of a ferrite pigment as described above for incorporation in anticorrosive paint formulation, plastic formulation or concrete formulation; and the use of a magnetite pigment as described above for incorporation in a paint formulation, plastic formulation or toner formulation to provide magnetic properties.
  • Figure 1 is a flow chart of the process according to a first variant suitable for producing ferrite pigments of the first grade.
  • Figure 2 is a flow chart of the process according to a second variant suitable for producing ferrite pigments of the second grade.
  • Figure 3 is a flow chart of the process according to a third variant suitable for producing ferrite pigments of the third grade.
  • Figure 4 is a flow chart of the process according to a fourth variant suitable for producing ferrite pigments of the fourth grade.
  • Figure 5 is a flow chart of the process showing a fifth and a sixth variant suitable for producing magnetite pigments of the first grade and the second grade.
  • Figure 6 is a flow chart of the process according to a seventh variant suitable for producing ferrite/magnetite pigments.
  • Figure 7 is a graph showing extraction values for calcium, chromium, zinc and lead versus time, and using a hydrofoil impeller.
  • Figure 8 is a series of graphs representing the variation of the zeta potential, ph and conductivity versus the concentration of sodium metaphosphate for a partly washed dust slurry.
  • Figure 9 is a graph showing extraction values for calcium, chromium, zinc and lead versus time, and using a high shear impeller.
  • Figures 10 to 13 are graphs showing the granulometric distribution of the first fraction (ferrite fraction) after one or two passes in the grinder
  • Figure 14 is a photo of ferrite pigments taken with an AFM microscope after wet grinding by attrition, showing the state of agglomeration and the fine size of the constituent ferrite fragments.
  • the ferrite pigments were produced according to the first, second, third and fourth variants of the process shown in figures 1 to 4; the magnetite pigments were produced according to the fifth and sixth variant of the process shown in figure 5, and the ferrite/magnetite pigments were produced according to the seventh variant of the process shown in figure 6.
  • the novelty of the process for all grades of pigment resides in an initial treatment of the EAF dust with water with the addition of an anionic surfactant.
  • This surfactant increases the efficiency and quality of the ferrite/magnetite separation by the magnetic separator.
  • This initial treatment also enables the decontamination of the dust by leaching salts, metals and simple oxides such as lead oxide.
  • This selective solubilization is due to the alcaline pH>12 solution resulting from the first washing (first mixing) and rinsing (second mixing) with water (Table 2).
  • This alcalinity promotes the solubilization of PbO and enables for the product to pass the test set out by the TCLP, which regulates standards of dangerous materials (Table 3).
  • the ferrite pigment of the first grade was produced with the aid of a solution containing an optimal concentration of surfactant, the concentration being a function of the isoelectric point of the dust to be treated, and with a leaching hereafter referred as to the second treatment) with water only.
  • the first grade ferrite pigment contained a high quantity of lead that cannot be easily leached under normal pH conditions. After ten months and many agitations in water, this pigment showed no leaching of heavy metals (Table 4) and is comparable to pigments of the second and third grade described below. Heavy metals, with the exception of 8% zinc in the resistant form of zincite, wave present and stabilized in the structure of certain ferrites and spinels.
  • the ferrite pigments of the first grade demonstrated high resistance to corrosion as demonstrated in the salt spray (mist) tests, allowing coated metallic plates to resist corrosion for more than 1500 hours in a salt mist, which is equal or superior to all other pigments, including those of commercial quality used in the tests.
  • the first grade ferrite pigment owes its corrosion (salt mist) resistance to CaO, which is sacrificed as Ca(OH) 2 and/or to the resulting alcaline viscosity (soapy appearance) associated with Ca(OH) 2 and the pigment's elevated alcalinity.
  • the ferrite pigment of the second grade was produced in the same way as the first grade, except that the second treatment was performed with sulphuric acid.
  • the preparation steps for the second grade pigments were identical to those used for the ferrite pigments of the first grade, the addition of the surfactant occurring after the first washing but before the magnetic separation.
  • leaching using sulphuric acid at a pH between 0,5 and 3 allowed for the preservation of a certain quantity of hydrated calcium sulphate, the solubilization of all the Zn in the form of zincite (ZnO) and the stabilization of lead as a solid sulphate.
  • ZnO zincite
  • lead lead as a solid sulphate.
  • the effluents rich in zinc sulphate are a suitable form of compound to be directly recycled back into an electrolysis process, in order to recuperate the value of the zinc.
  • the calcium sulphates generated by the leaching are not harmful in anticorrosion paints.
  • Calcium sulphate is frequently used as a filler with pigments used in paints and is often desirable as a pigmentary additive. This pigment did not require wet grinding by attrition, nor did it require a second magnetic separation and a second screening after acid leaching. The pigment was filtered in order to obtain an allowable soluble salt concentration of 0.3g/l mg, and was then dried and micronized.
  • the second grade of ferrite pigments allowed for the conservation of a fraction of calcium, the transformation of lead oxide into lead sulphate (which is very stable) and the solubilization of zinc oxide into zinc sulphate. These characteristics of the second grade pigment make this pigment an excellent colorant as well as a corrosion resistant pigment.
  • the ferrite pigment of the third grade was produced in the same way as the first grade, except that the second treatment was performed with nitric acid.
  • the leaching with nitric acid enabled the preferential removal of lead and other heavy metals due to the oxidizing property of the acid.
  • the leaching was performed at a pH between 0 and 3, which permitted the elimination of certain families of ferrites, as a function of the pH, in order to minimize the total lead in the pigment and to give a pigment with a particular signature with regards to its composition, structure and surface characteristics.
  • a pH of 3 and 1.5 the ferrites displayed a zeta surface potential that is positive, but this potential became negative at a pH ⁇ 1.5. This charge characteristic influenced the acceptable coatings and their associated mechanisms.
  • This thermal resistance is a requirement for plastics, powdered paint and ceramics.
  • This pigment can be used in concrete as a cement additive that increases the fluidity and compression resistance of the concrete.
  • This pigment had a finer granulometry than the third grade, ferrite pigment and the ferrite/magnetite pigment.
  • the ferrite pigments of the first, second, third and fourth gradse have applications in anticorrosive paints.
  • the third grade can be used in plastics and powder paints due to its thermal resistance. This pigment can also be used as a cement additive, thinning agent and additive in high performance concrete.
  • the major difference between the second and third grade ferrite pigments lies in their surface properties.
  • the magnetite pigment of the first grade was produced by grinding with a ball mill the magnetic fraction issuing from the magnetic separation.
  • the ground fraction was passed through a screening between 38 and 6 ⁇ m, and wet grinding by attrition in order to result in a median granulometry of about 0,3 ⁇ m.
  • the pigment was then filtered, coated with an organic coating, dried and micronized.
  • the magnetite pigment of the second grade was obtained by screening the magnetic fraction, which had already undergone ball mill grinding, at 6 ⁇ m. This fraction was purified by putting the silica, carbonate and residual ferrite contaminants into suspension, with the aid of an anionic dispersive surface active.
  • this pigmentary grade of magnetite was obtained by screening at 6 ⁇ m the magnetic fraction of the magnetic separation and the fractions less than 6 ⁇ m coming from the screening of the rough magnetite after its ball mill grinding.
  • This fraction which contained a concentration of magnetite, was purified by putting the silica carbonate and ferrite residue contaminants into suspension with the help of a surfactant. Two successive treatments of adding surfactant, followed by a decantation of the magnetite and separation of the suspension, were required to obtain an adequately black product which was subjected to wet grinding by attrition in order to attain a desired granulometry. The solid was finally filtered with an organic additive, dried and micronized. This step of purification is similar to the first treatment of the dust.
  • the ferrites and contaminants were put into suspension, and the magnetite was decanted. A rough non pigmentary magnetite was also produced. It was obtained after attrition grinding the magnetic fraction coarser than 30 ⁇ m. The attrition cleans the surface of the magnetite spheres by wearing out the white coating of calcium and silicate initially present. This step improves the black color of the spheres and eliminates the magnetites which are less resistant to abrasion.
  • the 70 and 30 ⁇ m product can be used as a toner in photocopy processing. The commercial niche of this solid depends on its granulometry, morphology, resistance to friction and magnetic properties.
  • Ferrite/magnetite pigment suitable as a colorant for concrete was produced with nitric acid at a pH of 3 but without magnetic separation.
  • the slurry from the first treatment was subjected to the following steps: screening at 6 ⁇ m, leaching in nitric acid, filtration in order to reduce its soluble salt content, and drying in a flash dryer, yielding a coarse pigment made up of agglomerates having a median grain size of ⁇ m.
  • the screening enabled the removal of coarser contaminants including silica, coal and other fragments.
  • the slurry containing a magnetic charge underwent leaching with nitric acid at a pH of 3 in order to remove the zincite, since zincite delays the setting of cement.
  • the product was filtered in order to reduce its soluble salt content, after which drying in a flash dryer gave the pigment a granulometry with a median of about 5 ⁇ m.
  • the pigment cannot be used as an additive in cement, in order to make high performance concrete.
  • an organic additive was provided for the finished product. in order to standardize the surface charges, to facilitate the incorporation of the dry pigment into paint resins, and to give a desired fluidity for its handling. It is however worth mentioning that the coating step is optional to the process.
  • the process for treating EAF dust according to the invention is a hydrometallurgical process for the treatment of steel mill electric arc furnace (EAF) dust that contains agglomerates of small ferrite particles and larger magnetite particles, the ferrite particles coating by adsorption the larger magnetite particles, the dust further containing calcium and toxic amount of leachable lead together with minor elements selected from the group consisting of Mg, Cr, Cu, Cd, V, and chlorides.
  • EAF steel mill electric arc furnace
  • Ferrites represent a complex family of compounds represented chemically by the major elements Ca, Fe, Zn, Mg, which are the major and important elements in this process together with minor elements selected from the group consisting of manganese, chromium, copper, cadmium, lead, vanadium and chlorides. Most of the elements are represented as oxides; either complex oxides like the ferrites or simple oxides represented by PbO, ZnO, CaO some other salts and metals are also present. This process also applies to EAF dust with low zinc content generated from the use of pre-reduced iron ore pellets of hematite.
  • the process steps according to different preferred variants of the process are illustrated in figures 1 to 6, for the different grades of pigments. They show a hydrometallurgical batch process with no atmospheric emissions.
  • the dust slurry of the first washing step is composed essentially of ferrites (65-75%), magnetites (20-28%), zincite (ZnO) and litharge (PbO) (8%), CaO/Ca(OH)2 (5-12%) and variable concentrations of silica and coal.
  • the process comprises a first treatment which essentially consists of washing and rinsing the EAF dust for reducing the amount of calcium and soluble lead, to thereafter facilitate further treatment of the dust to produce commercial grade pigments.
  • the first treatment which is performed in a tank (10) comprises the steps of : a) washing the EAF dust (12) in water to dissolve soluble salts, metals and simple oxides contained in the dust, the washing step being performed with an alkaline pH which is preferably greater than 12;
  • step b) decanting the solution of step a) to obtain a supernatant liquid (14) containing the dissolve salts, metals and simple oxides and a slurry (16) containing ferrites and magnetites, a non toxic amount of leachable lead and a reduced amount of calcium;
  • step d) adding to the slurry obtained in step c) an anionic surfactant (18), preferably a phosphate and most preferably sodium metaphosphate, to disperse the ferrite particles adsorbed on the magnetite particles.
  • an anionic surfactant preferably a phosphate and most preferably sodium metaphosphate
  • the sequence of steps a) to c) is performed more than one time before adding the anionic surfactant. Note that steps a) to c) are not shown in the figures.
  • Steps a) to d) are performed in the tank (10) shown in each of figures 1 to 6.
  • the slurry (16) from step d) is sent to further stages of the process to produce pigments selected from the group consisting of ferrite pigments, magnetite pigments and ferrite/magnetite pigments.
  • the treatment of the slurry (16) will vary depending on the grade of ferrite or magnetite to be produced. The production of each of these grades according to the process of the invention will be described in further detail further below.
  • the EAF dust was washed with water under agitation provided by a hydrofoil impeller with a rotation speed of approximately 350 rpm in a tank.
  • the height of the fluid level and the tank diameter had a ratio of 1 :1.
  • the tank agitation system also comprised four baffles, which acted as static agitators.
  • the concentration of the slurry was 16%. Tests were made with batches of 10, 20 and 30 kg of dust for 60 liters of liquid, corresponding to solid concentrations of 16, 32 and 48% respectively..
  • the washing provided:
  • the duration of agitation was 60 minutes and it was followed by a decantation period of 60 minutes and a separation of the supernatant liquid. Given the high specific weights of the ferrites and magnetites, decantation of the slurry solid was used instead of filtration.
  • the slurry from the washing was rinsed with water.
  • Water is preferable:
  • the rinsing was carried out for a period of 60 minutes, followed by a 60 minute decantation and recuperation of the supernatant liquid.
  • a surfactant had various objectives in the process. Firstly, it reduced the positive charge of the fine particles of the pulp represented by a zeta of 32 mV in order to attain the isoelectric point (zeta of 0 mV) for the system (slurry). This reduction of the charge of the chemical phases of the system facilitated the fractionation of the composites. Further details on the effect of the surfactant on the charge of the chemical phases are given in the section entitled "Magnetic separation" hereinbelow. Secondly, when a phosphate such as sodium metaphosphate was used, the surfactant temporarily confined the CaO coming from the ferrites by coating the surface of the particles with phosphate.
  • the surfactant was able to convert the calcium already in solution into calcium phosphate, which was insoluble in the solution and was concentrated with solid. It was also believed that some of the lead in solution is also precipitated in the form of a lead phosphate or in the form of a calcium and lead phosphate phase.
  • the alkaline solutions of the effluents (80 liters) were used in the effluent treatment.
  • the alkaline liquid was mixed with the acid effluents of the second treatment which will be described further below, in order to neutralize their acidity and to promote precipitation of the metals in solution.
  • This first treatment (washing) of the raw EAF dust which generated an alkaline solution, also promoted the solubilization of soluble salts in simple lead and zinc oxides to a concentration that satisfies the governing standards of the TCLP test, and the rules governing dangerous materials.
  • the leachate of the dust did not exceed the TCLP (Table 3) standard and thus is neither considered as contaminated, nor held under the rules of dangerous materials.
  • the slurry (16) is either sent to the magnetic separation (20) to separate the magnetite particles and the ferrite particles, as in figures 1 to 5, which show the first to sixth variants; or it is sent to screening (30) and thereafter to the second treatment (40), as in figure 6 which shows the seventh variant, to ultimately produce a pigment of ferrite and magnetite suitable for use as a colorant for concrete.
  • the first to the sixth variants which concern the production of ferrite pigments (figures 1 to 4) and the production of magnetite pigments (figure 5), will now be described in further detail while referring to figures 1 to 5.
  • the slurry (16) from the first treatment was subjected to a magnetic separation (20) to obtain a ferrite fraction (24) and a magnetite fraction (26). Both these fractions (24 and 26) were respectively subjected to a screening (30 or 32).
  • the refined ferrite fraction (34) from the screener (30) was further subjected to a second treatment (40) depending on the grade of ferrite pigments produced.
  • the second treatment was preceded by at least one of the following steps: decantation (60), grinding (50 or 55), and magnetic separation (200).
  • the slurry (46) obtained was subjected to filtration (70), and thereafter to the typical process steps used in the field of pigment production, as for example drying (90), coating (80) and micronization (100).
  • the filtration step (70) produces water to be recycled (72).
  • the second treatment was preferably followed by a second magnetic separation (200,
  • the ferrite fraction (206, 226) was sent back to the ferrite production line for producing the ferrite pigments, whereas the magnetite fraction (202, 222) was sent to the magnetite production line.
  • the magnetic fraction (26) from the magnetic separation (20) was sent, preferably with magnetic particles (202, 212, 222) from other steps of the process, to a first screening (30) at 150 ⁇ m.
  • the fraction (38) of less than 150 ⁇ m was sent to a ball mill (500) and then to a second screening (32) to obtain a first finer fraction (304) with particles having a grain size of 6 ⁇ m or less; and a coarser fraction (306) with particles having a grain size greater than 6 ⁇ m.
  • the coarser fraction (306) was then milled and screened at 40 ⁇ m (these steps are not shown on figure 5) to finally obtain a coarser fraction containing particles having a grain size between 40 and 6 ⁇ m.
  • the coarser fraction (306) was wet grinded by attrition (50) to attain a mean grain size of approximately 0,3 ⁇ m. It was thereafter subjected to the typical process steps used in the field of pigment production, as for example drying (90), coating (80) and micronization (100).
  • the finer fractions (304) were purified by suspending (600) residual contaminants contained therein with an anionic surfactant (802), to obtain a purified magnetic fraction (602).
  • the magnetic separation step (20) yields the first fraction (24) containing in a major portion ferrite particles and the second fraction (26) containing in a major portion magnetite particles.
  • the black magnetite In the raw EAF dust, the black magnetite is never apparent or visible to the naked eye, even though the magnetite is large and rough compared to the other components of the dust. This phenomenon is explained by the adsorption of the ferrites to the surface of the magnetites. In the raw dust, the ferrites are positive and the magnetite is negative, which causes an electrostatic attraction between these two chemical phases. This charge can be measured with an apparatus called " Electroacoustic Sonic Amplitude (ESA)", which enables the calculation of the zeta potential of the particles in aqueous medium, and the indirect and qualitative evaluation of the surface charge of the particles.
  • ESA Electroacoustic Sonic Amplitude
  • ferrites have a positive charge with a zeta of +27 mV, whereas the magnetites are lightly negative and have a zeta of -3 mV, which corresponds to the charge values for naturally occurring magnetites.
  • the ferrites have a granulometry under 1 ⁇ m, they will coat the large rough surface of the magnetite. This rough texture of the magnetite surfaces seems to be produced by the deposition of phases of calcium and other composites which can be removed by attrition. These factors render it difficult to separate ferrites from magnetites.
  • Laboratory experience teaches us that without a surfactant, it is possible to obtain a fraction concentrated in magnetite, but this fraction is brown and not black, and has a large proportion of ferrites trapped with the concentrated magnetite.
  • an anionic surfactant preferably sodium metaphosphate
  • the positive charge of the ferrites is neutralized and can be inverted to attain negative charges with an intensity of -40 to -160 mV, and lower.
  • the addition of surfactant increases the surface charges of the fine ferrites, decreases the cohesion or the attraction between the ferrites and magnetites, causes a stronger repulsion between the particles of ferrites and maintains these ferrites in suspension.
  • the coarse magnetic fraction which has a very small specific surface, is not greatly affected by the addition of surfactant.
  • the granulometry and the mass of the magnetites enable the decantation of the magnetite with the ferrite in suspension. This procedure substantially improves the results of the magnetic separation and the screening.
  • the condition at the isoelectric point is preferable in order to optimize the magnetic separation and the screening (see next section), while controlling the concentration of lead in the solid. Evaluation of the results
  • Magnetic separation in aqueous medium was performed with a drum for which a magnetic field was generated by an electro-magnet with a maximum power of about 1200 gauss.
  • the slurry (16) which had a concentration of solids of 16% and a mass concentration of surfactant varying from 0,1% to 1 ,3%, was used in the separation. Magnetic separators are well known and do not need further description.
  • the slurry (16) was fed with a flow rate of 1 l/min. To unstick the magnetic fraction from the drum, an additional flow of water (22) of 1 ,4 I/min was added, totaling 150 liters of liquid (to recycle) with a concentration of 3% solids to be recuperated by decantation (60) and screening (30).
  • the maximum fraction of magnetite recuperated in the pulp varied from one company to another according to its production. However, the maximum fraction recuperated was on the order of 15 to 20% for the producer using a pre-reduced hematite mineral and between 8 to 10% for the producer using scrap iron only.
  • the efficiency of the magnetic separation is supported by the mass values of the quantity of ferrite trapped by the magnetite.
  • the weights of the fractions indicate that without the addition of surfactant, the ferrite trapped by the magnetite reached a maximum.
  • the quantity of ferrite decreased (Table 8).
  • the adsorption of the surfactant occurred preferentially on the fine fraction of the solid and thus in this case, on the ferrites.
  • the surfactant for the process according to the invention, it is preferable to use the surfactant according to a specific dosage in order to produce two fractions (24 and 26) that are adequate for realizing products suitable for commercial applications, as will be explained in more details further below.
  • Screening of the ferrite fraction (24) or the magnetic fraction (26) is essential to produce ferrite pigments or magnetic pigments having a commercial value, because it allows the physical separation of larger agglomerates and certain contaminants accompanying the ferrites and magnetites. All particles or agglomerated substances of more than 20 ⁇ m with or without magnetic susceptibility, can be separated. Coal and even partially fused scrap metal fragments are separated by screening.
  • the addition of surfactant prevents the clogging of the screens and enables screening with openings of 20 to 6 ⁇ m.
  • the clogging is caused by portlandite, a calcium hydroxide Ca(OH)2, which is produced from lime in the raw EAF dust.
  • Portlandite in solution and in suspension is deposited on the walls of containers and, in particular, on the mesh of the screens, thus sealing the latter.
  • an appropriate surface active sodium metaphosphate
  • the calcium in solution is precipitated in the form of calcium phosphate. This precipitation is associated with the decrease in conductivity observed during the addition of surfactant and this decrease continues after reaching the isoelectric point, attaining, in certain cases, a minimum of conductivity (Figure 9).
  • the portlandite which adheres to surfaces and screen mesh must be cleaned with an acidic aqueous solution.
  • concentration of surfactant giving the minimum of conductivity is not preferred because such a high concentration of sodium metaphosphate interferes with the leaching of lead in the pulp.
  • a flow of water for screening (32) is used to facilitate the screening.
  • the rough screened fraction (36) issued from the first screening (30) was subjected to a magnetite separation (210) used to separate the magnetite fraction (212) that remained in the ferrite fraction (24).
  • the magnetite fraction (212) was sent to the magnetite production line, as shown in figure 5. WET GRINDING or grinding by attrition (50)
  • This wet grinding can be accomplished with silica sand, zirconium balls or other materials with a spherical morphology and sufficient hardness to resist abrasion.
  • the results provided were obtained with the zirconium beads with a range of granulometry of 0,4 to 0,6 mm in a horizontal grinder, with horizontal type disks. The grinding conditions and results are presented in Table 9.
  • the goal of this grinding is to break the large aggregates of more than 5 to 20 ⁇ m in order to give the ferrite pigment particles a restricted range of granulometry, more specifically, a bell curve distribution with a median around 0,3 ⁇ m.
  • the granulometric distribution after wet grinding assures that the fraction of rough aggregates of the dust is eliminated and transferred into the range of fine granulometry.
  • the obtained diameter (in surface) is from 0,25 to 0,28 ⁇ m, with a bell curve distribution desired for the pigments.
  • Figures 11 and 12 illustrate the granulometric distributions for slurries after one and two passes in the grinder.
  • the slurry does not require grinding, the granulometric median being already close to or just under 0,8 ⁇ m.
  • the first grade ferrite pigment requires grinding in order to obtain an adequate dispersion.
  • some dusts may contain enough aggregates around 20 ⁇ m as to require the use of a wet grinder.
  • wet grinding is necessary, because it decreases the granulometry, increases the surface contact between the particles, and generates new surfaces for a more efficient leaching at the second treatment (40).
  • the goal of the second treatment (40) is to leach the heavy metals still in the slurry, to eliminate the less stable ferrites and give certain required surface characteristics to the pigments (sign and zeta potential intensity), in order to improve the pigment compatibility in paints, plastics and concrete.
  • the chemical composition of the pigmentary spinels resulting from the second treatment (40) is represented by the chemical compositions given in Table 10.
  • These pigments represent various slightly differing ferrites or spinels rich in iron, zinc, magnesium and manganese and contain the elements Al, Si, Pb, Ni, Cr etc, as minority components. All minority components are stabilized in the structure of the spinels and the lead adheres to the leachate criteria of the TCLP and to the norms and expectations used by paint manufacturers of which the most stringent imposes a maximum concentration of 500 ppm of lead in paint.
  • the effect of the second treatment is illustrated in Table 10 by the variation of lead for the different third grade pigment leached at different pHs with nitric acid.
  • the most important variations are the lead concentrations and the zeta for the different pigments.
  • the sign of the relative charge represented by the zeta potential in aqueous medium is particularly important, the latter changing from +40mV for the first grade to-9 to 11 mV for the leached pigment at a pH of 1 ,5 to 0,5.
  • This parameter is important for the behavior of the pigment and also influences the pigmentary properties and the coating mechanism, or even the type of coating it can accept, if required.
  • a pulp of 8 to 10% solids in 55 liters of water was acidified with nitric acid 6 N to the desired pH by continuous addition of acid for a period of 30 min.
  • the pH was maintained for 60 min. by sporadically adding the acid while agitating the pulp. Decantation was preferred and the surpernatant liquid was removed.
  • the leaching agent In the first variant, simply water is used as the leaching agent. In the second variant, sulfuric acid (42) is used, and in the third variant, nitric acid (43) is used as the leaching agent.
  • the slurry (16) from the first treatment (10) was not subjected to magnetite separation.
  • the slurry was rather subjected to a screening at the 60 ⁇ m or less.
  • the finer fraction, hereinafter referred as to the refined slurry (33) was subjected to the second leaching treatment (40) with nitric acid (43) at a pH of about 3, to obtain a leached slurry (48) with no or a controlled amount of ZnO which retards the setting of concrete.
  • the leached slurry (48) was separated into a solid fraction (74) containing a mixture of ferrite and magnetite pigments and a liquid fraction (72) containing constituents soluble in nitric acid.
  • the solid fraction (74) was then dried (90) to obtain dry pigments containing a mixture of ferrite and magnetite.
  • the pigmentary properties for the ferrite pigments of the third grade are shown in Table 11 along with the commercial pigments recognized as ferrites. These commercial ferrites are obtained by mixing oxides according to a company- specific formulation and then calcining at high temperature.
  • the table shows different important quantitative pigmentary properties such as: pH; humidity; "long oil” absorption ; dry colour of pigment; • paint colour; gloss; dispersion on the Hegman gage; resin incorporation time
  • ferrite pigment of the third grade is its colour stability at temperatures exceeding 300 ° C.
  • Table 12 shows the colour parameters for a ferrite before and after heating to 300 ° C.
  • Salt mist tests for the pigments for which the properties were presented in the preceding section are given in Table 13 for exposure times of 500, 1000 and 1500 hours, in a chamber designed for accelerated corrosion testing.
  • Magnetite production uses the same treatment units with the exception of an impact grinder and a 6 ⁇ m screen. Normally, magnetite does not require leaching with acid and its surface characteristics are more constant.
  • the magnetite requires purification by putting ferrites and other contaminants such as calcium and silica into suspension. This suspension is accomplished with the aid of an anionic surfactant such as sodium metaphosphate or saratan. The required dosage, in order to optimize the suspension, is obtained after titrating the pulp with the surfactant.
  • the salt mist tests are also represented in this table for the magnetites.
  • Magnetite has morphologic and magnetic properties that enable it to be used in inks (Toner) of photocopiers.

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Abstract

Un procédé hydrométallurgique destiné au traitement des poussières de four électrique à arc (EAF) d'aciérie, qui contiennent des agglomérats de petites particules de ferrite et de particules de magnétite plus grandes. Ce procédé consiste à: a) laver les poussières provenant du four EAF dans l'eau pour dissoudre les sels, les métaux et les oxydes simples solubles qu'elle contient, ce lavage étant réalisé par agitation avec un pH alcalin; b) décanter la solution obtenue précédemment (a) pour obtenir un liquide surnageant qui renferme les sels, les métaux et les oxydes simples dissous, ainsi qu'une boue de ferrites et de magnétites, une quantité non toxique de plomb lixiviable et une quantité réduite de calcium; c) séparer la boue et le liquide surnageant; d) ajouter à la boue obtenue précédemment (c) un tensioactif anionique pour disperser les particules de ferrite adsorbées sur les particules de magnétite; et enfin, e) traiter la boue obtenue précédemment (d) pour produire des pigments sélectionnés dans le groupe constitué par des pigments de ferrite, des pigments de magnétite et des pigments de ferrite/magnétite.
PCT/CA2004/002147 2003-12-17 2004-12-16 Procede de separation hydrometallurgique de poussieres de four electrique a arc (eaf) d'acierie et pigments ainsi obtenus WO2005059038A1 (fr)

Priority Applications (5)

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MXPA06006918A MXPA06006918A (es) 2003-12-17 2004-12-16 Un proceso de separacion hidrometalurgica de polvo de horno de arco electrico (eaf) de fabrica siderurgica y los pigmentos obtenidos por el proceso.
DE112004002509T DE112004002509T5 (de) 2003-12-17 2004-12-16 Verfahren zur Hydrometallurgischen Behandlung von Stahlwerk-Lichtbogen-Elektroofen(EAF)-Staub und die bei diesem Verfahren erhaltenen Pigmente
BRPI0417201-9A BRPI0417201A (pt) 2003-12-17 2004-12-16 processo de separação hidrometalúrgico de pó de forno a arco elétrico ( eaf ) de aciaria e os pigmentos obtidos pelo processo
CA 2549070 CA2549070A1 (fr) 2003-12-17 2004-12-16 Procede de separation hydrometallurgique de poussieres de four electrique a arc (eaf) d'acierie et pigments ainsi obtenus
US10/583,183 US20070214912A1 (en) 2003-12-17 2004-12-16 Hydrometallurgical Separation Process Of Steel Mill Electric Arc Furnace (Eaf) Dust And The Pigments Obtained By The Process

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CA 2453005 CA2453005A1 (fr) 2003-12-17 2003-12-17 Procede hydrometallurgique de separation des poussieres d`acieries utilisant un four a arc et pigments obtenus par le procede
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1899425A1 (fr) * 2005-06-17 2008-03-19 Ferrinov Inc. Pigments anti-corrosion derives de poussieres d'un four a arc electrique et contenant du calcium sacrificiel
WO2012032256A1 (fr) 2010-09-06 2012-03-15 Associates Researchers And Engineers Procede de valorisation de poussieres d'acieries electriques
WO2014044992A1 (fr) 2012-09-24 2014-03-27 Mine & Ore Procede de traitement pyrometallurgique des poussieres d'acierie issues de la fusion de ferrailles de recuperation
WO2014044993A1 (fr) 2012-09-24 2014-03-27 Mine & Ore Procede de traitement hydrometallurgique des poussieres d'acierie issues de la fusion de ferrailles de recuperation
RU2683100C1 (ru) * 2017-12-01 2019-03-26 Общество с ограниченной ответственностью "РосМет" Способ получения минеральных железосодержащих пигментов и наполнителей

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011060505A1 (fr) * 2009-11-23 2011-05-26 Sce Industrial Services Nsw Pty Ltd Procédé de traitement de poudre de déchets métallurgiques
CN109456617B (zh) * 2018-11-21 2020-11-06 武汉科技大学 一种黑色陶瓷颜料及其制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1184363A (fr) * 1981-09-12 1985-03-26 Franz Hund Production et emploi de pigments a base de ferrite de zinc faiblement halogene
CA1186885A (fr) * 1982-03-27 1985-05-14 Hans-Peter Biermann Pigments thermostables a base d'oxyde de fer
CA1331274C (fr) * 1988-06-24 1994-08-09 Jurgen Wiese Pigments thermostables noirs a base d'oxyde de fer, procede de fabrication et utilisation connexes
CA2228562A1 (fr) * 1995-08-04 1997-02-20 Recupac Procede de preparation de pigments mineraux, pigments mineraux ainsi obtenus, et installation pour la mise en oeuvre d'un tel procede
CA2400854A1 (fr) * 2000-02-23 2001-08-30 Recupac Procede de valorisation des poussieres d'acieries

Family Cites Families (91)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1557990A (en) * 1924-12-05 1925-10-20 Fred D Doty Boat
US2404254A (en) * 1943-02-02 1946-07-16 Gen Electric Electrical apparatus
US2502130A (en) * 1947-08-29 1950-03-28 Columbian Carbon Preparation of magnesium ferrite pigment
US2904395A (en) * 1955-02-24 1959-09-15 Columbian Carbon Method for producing zinc ferrite pigment
US3904421A (en) * 1972-08-30 1975-09-09 Tada Kogyo Ltd Anticorrosive paint
US3832455A (en) * 1972-10-25 1974-08-27 Smith G Labor Preparation of zinc ferrite yellow pigments
FI50097C (fi) * 1973-02-12 1980-10-24 Outokumpu Oy Hydrometallurgiskt foerfarande foer aotervinning av zink koppar och kadmium fraon deras ferriter
DE2537684C3 (de) * 1975-08-23 1980-07-31 Bayer Ag, 5090 Leverkusen Aktive Korrosionsschutzpigmente auf Eisenoxidbasis
US4211565A (en) * 1975-08-23 1980-07-08 Bayer Aktiengesellschaft Iron oxide-based anti-corrosion pigments
ES444739A1 (es) * 1975-10-01 1977-08-16 Anglo American Clays Corp Un metodo para separar magneticamente contaminantes que ha- cen variar el color, poco susceptibles de ser atraidos mag- neticamente desde una arcilla.
FR2340376A1 (fr) * 1976-02-06 1977-09-02 Minemet Rech Sa Procede hydrometallurgique pour la dissolution selective de melanges de composes oxygenes
US4156613A (en) * 1976-06-05 1979-05-29 Bayer Aktiengesellschaft Anti-corrosion pigments
US4053325A (en) * 1976-09-14 1977-10-11 Pfizer Inc. Heat stable iron oxides
US4071357A (en) * 1976-09-23 1978-01-31 Hazen Research, Inc. Process for recovering zinc from steel-making flue dust
US4190422A (en) * 1977-05-24 1980-02-26 Bethlehem Steel Corporation Metallic abrasive produced from a steel mill waste material
US4432803A (en) * 1977-05-24 1984-02-21 Bethlehem Steel Corporation Iron oxide paint pigment precursor
JPS5413542A (en) * 1977-06-30 1979-02-01 Toda Kogyo Corp Aqueous corrosion preventive coating
US4292294A (en) * 1979-05-09 1981-09-29 Basf Wyandotte Corporation Yellow pigments stable at high temperatures
FR2459293B1 (fr) * 1979-06-15 1985-09-27 Siderurgie Fse Inst Rech Procede et dispositif de traitement hydrometallurgique des poussieres metallurgiques
US4286726A (en) * 1979-10-04 1981-09-01 Gary Madsen Floating deck leg boots
US4319988A (en) * 1980-05-05 1982-03-16 Halomet, Incorporated Separation of high grade magnetite from fly ash
US4432868A (en) * 1980-05-05 1984-02-21 Halomet, Incorporated Separation of high grade magnetite from fly ash
DE3022875A1 (de) * 1980-06-19 1982-01-14 Bayer Ag, 5090 Leverkusen Verfahren zur herstellung von eisenoxidpigmenten mit verbesserter reinheit sowie deren verwendung
US4758415A (en) * 1980-12-22 1988-07-19 Basf Corporation Process for removing soluble metal cations in iron oxide pigments
US4396423A (en) * 1981-06-22 1983-08-02 Stephens Jr Frank M Process for recovering iron and zinc from steel making dusts
US4386057A (en) * 1982-03-17 1983-05-31 The United States Of America As Represented By The United States Department Of Energy Recovery of iron oxide from coal fly ash
FR2535736B1 (fr) * 1982-11-04 1987-09-04 Promotion Procedes Hydro Metal Procede de traitement de poussieres contenant du zinc, issues de fours d'acieries electriques
US4409020A (en) * 1983-01-24 1983-10-11 The United States Of America As Represented By The Secretary Of The Interior Recovery of metals from grinding sludges
DE3409722A1 (de) * 1984-03-16 1985-09-26 Bayer Ag, 5090 Leverkusen Verfahren zur herstellung von gelbbraunen zinkferritpigmenten
DE3435698A1 (de) * 1984-09-28 1986-04-03 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von feinteiligem isotropen ferritpulver mit spinellstruktur
US4610721A (en) * 1985-01-31 1986-09-09 Amax Inc. Two-stage leaching process for steel plant dusts
US4610722A (en) * 1985-01-31 1986-09-09 Amax Inc. Process for metal recovery from steel plant dust
US4810368A (en) * 1985-04-10 1989-03-07 Electro Minerals (Canada) Inc. Automatic method for separating and cleaning silicon carbide furnace materials
GB8530361D0 (en) * 1985-12-10 1986-01-22 Gec Elliott Mech Handling Magnetic separators
US4652433A (en) * 1986-01-29 1987-03-24 Florida Progress Corporation Method for the recovery of minerals and production of by-products from coal ash
DE3605526A1 (de) * 1986-02-20 1987-08-27 Heubach Hans Dr Gmbh Co Kg Neue korrosionsschutzpigmente und ihre herstellung und anwendung
US4726895A (en) * 1986-03-28 1988-02-23 Edward Martinez Process for concentration of gold and uranium magnetically
US4669397A (en) * 1986-08-21 1987-06-02 Smith & Mahoney, P.C. Recovery of useful materials from refuse fuel ash
DE3636156A1 (de) * 1986-10-24 1988-04-28 Basf Ag Plaettchenfoermige pigmente der allgemeinen formel mn(pfeil abwaerts)x(pfeil abwaerts)-al(pfeil abwaerts)y(pfeil abwaerts)fe(pfeil abwaerts)2(pfeil abwaerts)(pfeil abwaerts)-(pfeil abwaerts)(pfeil abwaerts)((pfeil abwaerts)(pfeil abwaerts)x(pfeil abwaerts)(pfeil abwaerts)+(pfeil abwaerts)(pfeil abwaerts)y(pfeil abwaerts)(pfeil abwaerts))(pfeil abwaerts)o(pfeil abwaerts)3(pfeil abwaerts)
US4803061A (en) * 1986-12-29 1989-02-07 Texaco Inc. Partial oxidation process with magnetic separation of the ground slag
DE3709217A1 (de) * 1987-03-20 1988-09-29 Basf Ag Plaettchenfoermige pigmente auf basis eisenoxid
ES2006347A6 (es) * 1988-03-03 1989-04-16 Colores Hispania Pigmento anticorrosivo y procedimiento para su obtencion.
CA1292856C (fr) * 1988-03-21 1991-12-10 Gary Derdall Methode d'affinage du kaolin
DE3819626A1 (de) * 1988-06-09 1989-12-14 Bayer Ag Thermostabile zinkferrit-farbpigmente, verfahren zu ihrer herstellung sowie deren verwendung
US5176260A (en) * 1988-09-28 1993-01-05 Exportech Company, Inc. Method of magnetic separation and apparatus therefore
US5127586A (en) * 1988-09-28 1992-07-07 Exprotech Company, Inc. Method of magnetic separation and apparatus therefore
US4940550A (en) * 1989-05-02 1990-07-10 The Curators Of The University Of Missouri Multi-step process for concentrating magnetic particles in waste sludges
US5227349A (en) * 1989-09-20 1993-07-13 Ecc International Inc. Process for producing a kaolin clay product
DE4003255A1 (de) * 1990-02-03 1991-08-08 Bayer Ag Schwarzes mangan-eisenoxid-pigment, verfahren zu seiner herstellung sowie dessen verwendung
US5227047A (en) * 1990-05-24 1993-07-13 Board Of Control Of Michigan Technological University Wet process for fly ash beneficiation
US5047145A (en) * 1990-05-24 1991-09-10 Board Of Control Of Michigan Technological University Wet process for fly ash beneficiation
US5082493A (en) * 1990-06-18 1992-01-21 Hatch Associates Ltd. Processing of carbon steel furnace dusts
JP2695678B2 (ja) * 1990-06-20 1998-01-14 三菱重工業株式会社 排煙脱硫方法
DE4020229A1 (de) * 1990-06-26 1992-01-02 Mann & Hummel Filter Verfahren und vorrichtung zur aufbereitung von rueckstaenden aus der spanabhebenden bearbeitung ferromagnetischer werkstoffe
US5336421A (en) * 1990-11-22 1994-08-09 Toda Kogyo Corp. Spinel-type spherical, black iron oxide particles and process for the producing the same
KR920016348A (ko) * 1991-02-05 1992-09-24 도오사끼 시노부 고순도 산화철 및 그 제조방법
US5393412A (en) * 1991-05-03 1995-02-28 Ashland Oil, Inc. Combination magnetic separation, classification and attrition process for renewing and recovering particulates
US5234669A (en) * 1991-08-08 1993-08-10 Idaho Research Foundation, Inc. Recovery of non-ferrous metals from smelter flue dusts and sludges
US5221323A (en) * 1991-10-03 1993-06-22 Li Chung Lee Method of producing magnetic powders from heavy metal sludges
WO1993007967A1 (fr) * 1991-10-15 1993-04-29 Genesis Research Corporation Procede d'epuration de charbon
DE4141676C1 (fr) * 1991-12-18 1993-04-15 Mann & Hummel Filter
US5942198A (en) * 1992-01-15 1999-08-24 Metals Recycling Technologies Corp. Beneficiation of furnace dust for the recovery of chemical and metal values
US5332493A (en) * 1992-04-28 1994-07-26 Ecc International Inc. Method for improving rheological properties of kaolin clays
FR2691649B1 (fr) * 1992-05-29 1995-06-02 Extramet Sa Procédé de décontamination des terres polluées par des métaux.
JP2540281B2 (ja) * 1992-07-29 1996-10-02 クムサン マテリアル カンパニー リミテッド 摩擦材用粉鉄の原料及びその還元処理方法
US5738717A (en) * 1993-02-11 1998-04-14 Corveagh Limited Coloring pigment and method of manufacture
US5342443A (en) * 1993-04-06 1994-08-30 Engelhard Corporation Method for bleaching kaolin clay
US5462173A (en) * 1994-03-04 1995-10-31 Eriez Manufacturing Company Rotating drum magnetic separator
KR0163819B1 (ko) * 1994-08-05 1998-11-16 사코 유키오 마그네타이트 입자 및 그 제조방법
US5534234A (en) * 1994-11-14 1996-07-09 Reddin; Lorin D. Recovery of manganese from leach solutions
US5570469A (en) * 1995-01-06 1996-10-29 Lockheed Martin Corporation Method for removing metal contaminants from flue dust
US5709730A (en) * 1995-01-23 1998-01-20 Cashman; Joseph B. Hydrometallurgical processing of flue dust
US5912402A (en) * 1995-10-30 1999-06-15 Drinkard Metalox, Inc. Metallurgical dust recycle process
US6361753B1 (en) * 1995-12-26 2002-03-26 Joseph B. Cashman Converting zinc chloride to zinc oxide during the hydrometallurgical processing of flue dust
US5954969A (en) * 1996-04-15 1999-09-21 Hedin; Robert S. Recovery of iron oxides from polluted coal mine drainage
CN1057131C (zh) * 1996-05-28 2000-10-04 L及C斯泰因米勒(非洲)(私人)有限公司 流化床处理电弧炉粉尘
DE19625267A1 (de) * 1996-06-25 1998-01-08 Bayer Ag Verfahren zur Herstellung anorganisch beschichteter Pigmente und Füllstoffe
US5906671A (en) * 1996-10-25 1999-05-25 Agglo Inc. Method for extraction of metals and non-metals from minerals, industrial by-products and waste materials
GB2333518A (en) * 1998-01-26 1999-07-28 Laporte Industries Ltd Process for making black iron oxide pigment
US6186335B1 (en) * 1998-03-20 2001-02-13 Thiele Kaolin Company Process for beneficiating kaolin clays
DE19812260A1 (de) * 1998-03-20 1999-09-23 Bayer Ag Verfahren zur Herstellung von Eisenoxid-Pigmenten aus Dünnsäure aus der TiO¶2¶-Herstellung
EP0952230A1 (fr) * 1998-03-24 1999-10-27 KABUSHIKI KAISHA KOBE SEIKO SHO also known as Kobe Steel Ltd. Procédé de préparation d'agglomérés de fer réduit
US6361749B1 (en) * 1998-08-18 2002-03-26 Immunivest Corporation Apparatus and methods for magnetic separation
KR20000052340A (ko) * 1999-01-23 2000-08-25 이호인 아연페라이트가 함유된 제강분진으로부터 염산과 금속아연의 회수방법
US6242098B1 (en) * 1999-02-17 2001-06-05 Mineral Resources Technologies, Llc Method of making mineral filler and pozzolan product from fly ash
US6139960A (en) * 1999-02-17 2000-10-31 Mineral Resource Technologies, Llc Method of making a mineral filler from fly ash
US6197200B1 (en) * 1999-05-11 2001-03-06 Eastroc Llc Method of purifying flue gas waste slurries for use in gypsum production
US6770249B1 (en) * 1999-09-27 2004-08-03 Chester W. Whitman Process to selectively recover metals from waste dusts, sludges and ores
US6679823B2 (en) * 2001-05-04 2004-01-20 Envirosafe Services Of Ohio, Inc. Treatment of electric arc furnace dust to resist acid and alkaline leaching of heavy metals
IL143551A0 (en) * 2001-06-04 2002-04-21 Pigmentan Ltd Paints and coatings composition useful for corrosion inhibition and a method for production therefor
US6758894B1 (en) * 2003-04-17 2004-07-06 The Shepherd Color Company Strontium iron manganese black pigment

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1184363A (fr) * 1981-09-12 1985-03-26 Franz Hund Production et emploi de pigments a base de ferrite de zinc faiblement halogene
CA1186885A (fr) * 1982-03-27 1985-05-14 Hans-Peter Biermann Pigments thermostables a base d'oxyde de fer
CA1331274C (fr) * 1988-06-24 1994-08-09 Jurgen Wiese Pigments thermostables noirs a base d'oxyde de fer, procede de fabrication et utilisation connexes
CA2228562A1 (fr) * 1995-08-04 1997-02-20 Recupac Procede de preparation de pigments mineraux, pigments mineraux ainsi obtenus, et installation pour la mise en oeuvre d'un tel procede
CA2400854A1 (fr) * 2000-02-23 2001-08-30 Recupac Procede de valorisation des poussieres d'acieries

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JEBRAK M. ET AL: "Characterisation et technologie de traitement des poussieres d'acierage a Sorel-Tracy.", QUEBEC DEPARTMENT OF THE ENVIRONMENT-ST. LAWRENCE CENTRE, ENVIRONMENT OF CANADA., March 1993 (1993-03-01) *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1899425A1 (fr) * 2005-06-17 2008-03-19 Ferrinov Inc. Pigments anti-corrosion derives de poussieres d'un four a arc electrique et contenant du calcium sacrificiel
EP1899425A4 (fr) * 2005-06-17 2011-11-16 Ferrinov Inc Pigments anti-corrosion derives de poussieres d'un four a arc electrique et contenant du calcium sacrificiel
WO2012032256A1 (fr) 2010-09-06 2012-03-15 Associates Researchers And Engineers Procede de valorisation de poussieres d'acieries electriques
WO2014044992A1 (fr) 2012-09-24 2014-03-27 Mine & Ore Procede de traitement pyrometallurgique des poussieres d'acierie issues de la fusion de ferrailles de recuperation
WO2014044993A1 (fr) 2012-09-24 2014-03-27 Mine & Ore Procede de traitement hydrometallurgique des poussieres d'acierie issues de la fusion de ferrailles de recuperation
RU2683100C1 (ru) * 2017-12-01 2019-03-26 Общество с ограниченной ответственностью "РосМет" Способ получения минеральных железосодержащих пигментов и наполнителей

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