KR101394521B1 - A Treatment method of Electric arc furnace Dust - Google Patents

Abstract

The present invention relates to a method for manufacturing a steel sheet, Performing the reducing and firing step to separate and recover zinc and iron; Collecting the separated and recovered zinc component with zinc oxide; Advancing the oxidation and roasting of the zinc oxide; Collecting the dust-type powder containing Pb and Zn from the exhaust gas generated from the oxidizing roasting operation; Separating and recovering Pb and Zn in the collected dust; The present invention relates to a method of treating electric furnace steel dust, which comprises a step of carbonizing an electric furnace steel dust, and a step of carbonizing the separated and recovered Pb and Zn. In the method of treating electric furnace steel dust, , And an environmentally-friendly treatment effect can be obtained without any generation of additional secondary waste.

Description

Technical Field [0001] The present invention relates to a method of treating an electric arc furnace dust,

The present invention relates to a method for treating electric furnace steelmaking dust through a reduction process and an oxidation process, and more particularly, to a process for recovering zinc, lead, iron, The present invention relates to a method for treating electric furnace steel dust that can reduce environmental pollution because no additional secondary waste is generated.

Electric Arc Furnace Dust (EAFD) refers to particulate powder collected during the cooling process of fugitive dust or gaseous phase generated in the melting process of an electric furnace using scrap metal as the main material.

Generally, in the electric furnace steelmaking process for producing steel using scrap iron as a raw material, the electric furnace steel dust generated during the melting process is about 1 to 2% by weight of the amount of scrap iron to be input. Among such electric furnace steel dust, And the like.

The amount of the valuable metal to be recovered depends on the quality of the electric furnace steelmaking company and the steel scrap used as the steelmaking raw material, but it is approximately 1 to 7% by weight of lead, 1 to 35% by weight of zinc, 10 to 40% .

In addition, hazardous heavy metals such as cadmium, mercury, and chromium in addition to the above-mentioned valuable metals are classified as designated wastes in the electric furnace steel dust because they exceed the allowable limits in the waste management law.

On the other hand, the generation of domestic electric furnace steel dust is currently about 4,000 tons / year. In addition to the cost reduction and conservation of resources, the tendency to produce steel from steel scrap instead of iron ore is increasing worldwide Electric arc furnace dust emission amount is also increasing every year.

 However, until now, many researches related to the environmentally friendly treatment and recycling of electric furnace steel dust have been made, but all of them have not been able to make a simple experimental system of Lab-scale. And it does not have commercialized technology.

As a result, about 60% of the dusts generated in Korea are buried in the landfill. Therefore, the problem of resource loss due to the disposal of a large amount of valuable metals and the environmental problems of the leakage of harmful heavy metals into the groundwater are being raised at the same time.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned technical problems, and it is an object of the present invention to provide a method of treating electric furnace steel dust which can efficiently recover valuable metal contained in electric furnace steel dust, .

The problems to be solved by the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned can be clearly understood by those skilled in the art from the following description.

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing an electric furnace, comprising the steps of: Performing the reducing and firing step to separate and recover zinc and iron; Collecting the separated and recovered zinc component with zinc oxide; Advancing the oxidation and roasting of the zinc oxide; Collecting the dust-type powder containing Pb and Zn from the exhaust gas generated from the oxidizing roasting operation; Separating and recovering Pb and Zn in the collected dust; And conducting a carbonation reaction between the separated and recovered Pb and Zn. The present invention also provides a method of treating electric furnace steel dust.

In the present invention, the zinc (Zn) and lead (Pb) components contained in the electric furnace steel dust are volatilized in the gaseous state in the reducing and firing step, and the remaining components including iron (Fe) The present invention also provides a method of treating electric furnace steel dust.

In addition, in the present invention, the zinc (Zn) component volatilized in the gaseous state is subjected to reoxidation and cooling processes and is collected in a dust collector as crude zinc oxide in a solid state, and the solid in the form of a clinker Wherein the magnetic material is re-applied as an iron source through quenching, pulverizing and magnetic separation, and the non-magnetic material is reused as a raw material for cement.

Further, in the present invention, the Pb and Zn in the collected dust are separated and recovered by the wet process using hydrochloric acid (HCl), and the carbonation reaction between the separated Pb and Zn is carried out using soda ash (Na ₂ CO ₃ ) The present invention provides a method of treating electric furnace steelmaking dust.

Further, the present invention is characterized in that the Zn component in the collected dust is ionized into a Zn ⁺⁺ form to be recovered in the form of a zinc (Zn) filtrate, and the Pb component is recovered in the form of a solid form of lead chloride (PbCl ₂ ) To provide a method of treating steelmaking dust.

Further, according to the present invention, the Zn (Zn) filtrate is made of ZnCO ₃ in the form of solid by progressing the carbonization reaction between the separated Pb and Zn, and the lead chloride (PbCl ₂ ) ₃ , which is a process for treating electric furnace steelmaking dust.

As described above, according to the present invention, it is possible to efficiently recover the valuable metal contained in the electric furnace steel dust in the processing of the electric furnace steelmaking dust, and to provide an eco-friendly treatment effect without any additional secondary waste generation Can be obtained.

More specifically, in the primary treatment process for treating the electric furnace steel dust according to the present invention, zinc (Zn) is recovered as crude zinc oxide in a solid state, and the remaining components including iron (Fe) Clinker-type solids can be pulverized, magnetic materials can be re-applied to steelmakers as Fe-sources, and non-magnetic materials can be reused as raw materials for cement.

Further, in the secondary treatment process for treating the zinc oxide recovered in the primary treatment process according to the present invention, the oxidation and roasting of the crude zinc oxide proceeds to obtain a zinc oxide-type solid purified in high purity .

Further, in the secondary treatment step for treating the zinc oxide recovered in the primary treatment step according to the present invention, the zinc component in the trapping powder containing Pb and Zn is formed in Zn ⁺⁺ form Ionized to easily recover in the form of a zinc (Zn) filtrate, and the lead component can be easily recovered in the form of a solid of PbCl ₂ .

Further, in the secondary treatment process for treating the zinc oxide recovered in the primary treatment process according to the present invention, soda ash (Na ₂ CO ₃ ) is used to separate and recover PbCl ₂ in solid form and desalination of Zn filtrate High purity PbCO ₃ and ZnCO ₃ in solid form can be produced through the carbonation process.

1 is a schematic view showing a treatment method of electric furnace steel making dust according to the present invention.
2 is a flow chart showing a primary treatment process for treating electric furnace steel dust according to the present invention.
3 is a flowchart showing a secondary treatment process for treating zinc oxide recovered in the primary treatment process according to the present invention.
4 is a view showing the components of the solid matter of the exhaust gas collecting dust and the lead chloride (PbCl ₂ ).
FIG. 5A is a view showing the components of lead carbonate (PbCO ₃ ), and FIG. 5B is a diagram showing the result of phase analysis of lead carbonate (PbCO ₃ ).
6A is a graph showing the composition of zinc carbonate (ZnCO ₃ ), and FIG. 6B is a graph showing the result of phase analysis of zinc carbonate (ZnCO ₃ ).

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. &Quot; and / or "include each and every combination of one or more of the mentioned items. ≪ RTI ID = 0.0 >

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing a treatment method of electric furnace steel making dust according to the present invention.

Referring to FIG. 1, the method of treating the electric furnace making dust 100 according to the present invention can be roughly classified into two processes. More specifically, first, a first treatment process for treating the electric furnace steel dust 200), and second, a secondary treatment process 300 for treating the zinc oxide recovered in the primary treatment process.

The primary treatment process may include a reducing furnace process 210 and a zinc oxide recovery process 250. In the secondary treatment process, an oxidation furnace process 310 and a purified zinc oxide recovery process 320 ).

FIG. 2 is a flow chart showing a primary treatment process for treating electric furnace steelmaking dust according to the present invention, FIG. 3 is a view showing a secondary treatment process for treating zinc oxide recovered in the primary treatment process according to the present invention Fig.

1 and 2, the primary treatment process for treating the electric furnace steel dust according to the present invention will be described below.

Referring to FIGS. 1 and 2, in the first treatment process for treating the electric furnace steel dust according to the present invention, a reduction and firing process of the electric furnace steel dust is performed (S10).

As described above, the electric furnace steel making dust 100 refers to powder of particulate matter collected during cooling process of scattered dust or gas phase generated in the melting process of an electric furnace using scrap metal as the main material.

Generally, in the electric furnace steelmaking process for producing steel using scrap iron as a raw material, the electric furnace steel dust generated during the melting process is about 1 to 2% by weight of the amount of scrap iron to be input. Among such electric furnace steel dust, And harmful heavy metals such as cadmium, mercury, and chromium.

The main components of the electric furnace steel dust are shown in Table 1 below.

division Zn Fe Pb SiO ₂ CaO Al ₂ O ₃ Cl F CD wt% 20-25 20 to 40 2 to 5 2 to 10 2 to 10 1-5 2 to 7 0.2 to 0.5 0.02 to 0.1

The reduction roasting of the electric furnace steelmaking dust is carried out by first carrying the electric furnace steel dust to a closed type trailer and storing it in a closed type storage silo and then storing the stored electric furnace dust in a rotary kiln Kiln).

Next, the rotary kiln, which is the reducing furnace 210, is heated to a temperature range of 1150 to 1200 ° C. to reduce and calcine the charged pellets.

At this time, when the electric furnace steel dust is charged into the rotary kiln, the movement of the steel dust can be prevented by using a pneumatic conveyor type using compressed air.

Meanwhile, the electric furnace steel dust can be produced in the form of a pellet in order to uniformly mix solid reductants such as Cokes, Limestone, etc. and other additives at a predetermined mixing ratio and to increase reactivity.

1 and 2, the reducing and firing process is performed to separate and recover zinc (Zn) and iron (Fe) (S20).

More specifically, zinc (Zn), lead (Pb), and the like contained in the electric furnace steel dust are volatilized in a gaseous state in the reducing and firing step, and the remaining components including iron (Fe) It is discharged into the solid state in the form of clinker (220) at the rotary kiln end.

A typical reduction reaction formula of the reducing material in the reducing and calcining step is as follows.

C (s) + O ₂ (g) = CO ₂ (g)

C (s) + CO ₂ (g) = 2CO (g)

Zn (s) + C (s) = Zn (g) + CO (g)

ZnO (s) + CO (g) = Zn (g) + CO ₂ (g)

ZnO (g) + 1 / 2O ₂ (g) = ZnO (s)

ZnFe ₂ O ₄ (s) + 2C (s) = Zn (g) + 2Fe (s) + 2CO ₂ (g)

_{3ZnFe 2 O 4 (s) +} 2C (s) = 3Zn (g) + 2Fe 3 O 4 (s) + 2CO 2 (g) ---------- Scheme 7

3Fe ₂ O ₃ (s) + CO (g) = 2Fe ₃ O ₄ (s) + CO ₂ (g)

Fe ₃ O ₄ (s) + CO (g) = 3 FeO (s) + CO ₂ (g)

FeO (s) + CO (g) = FeO (s) + CO ₂ (g)

That is, the zinc (Zn) is recovered in a gaseous state, and the iron (Fe) is recovered in a solid state and can be separated and recovered.

At this time, the materials that are volatilized in the gaseous state, that is, zinc (Zn), lead (Pb), and the like are reoxidized and cooled, and finally, the zinc oxide Bag Filter) (S30).

Meanwhile, the noxious gas components that are not captured by the dust collecting apparatus can be adsorbed and collected in the secondary dust collecting apparatus by injecting activated carbon, so that all the discharged gas phases are collected in the form of particles, so that only the clean gas can be discharged to the outside .

In addition, the remaining components including iron (Fe) are discharged into a solid state in the form of a clinker through reduction of iron by minimizing the oxidizing atmosphere in the reducing furnace, and then the discharged clinker-type solid The magnetic material may be re-applied to the steelmaker as a Fe-source 230 through the quenching, crushing and magnetic separation process, and the non-magnetic material may be reused as the cement raw material 240.

The major components of the clinker discharged from the reduction furnace and the magnetic and non-magnetic materials obtained by pulverizing the same are shown in Table 2 below.

division Fe Zn CaO SiO ₂ Al ₂ O ₃ Clinker (wt%) 50.44 0.14 7.91 3.26 4.32 Magnetic material (wt%) 62.25 0.12 1.88 0.89 1.53 Non-magnetic material (wt%) 8.32 0.24 38.63 13.91 17.26

In the case of the conventional peers, the remaining components including iron (Fe), which is solid in the form of clinker, are treated as second-order scrap by-products and there is a fear of resource loss. In the present invention, ), And non-magnetic materials can be used as raw materials for cement to prevent resource loss.

As a result, in the primary treatment process for treating the electric furnace steel dust according to the present invention, zinc (Zn) is recovered as crude zinc oxide in a solid state, and the remaining components including iron (Fe) Type solid is pulverized, the magnetic material is re-applied to the steelmaker as an iron source (Fe-source), and the non-magnetic material can be reused as a raw material for cement.

1 and 3, a secondary treatment process for treating the recovered zinc oxide in the primary treatment process according to the present invention will be described below.

Referring to FIGS. 1 and 3, first, the oxidation and roasting of the crude zinc oxide 250 is performed (S110).

The zinc oxide corresponds to a raw material for the roasting of oxidizing roasting and may be the raw material recovered in the primary treatment step for treating the electric furnace steel dust as described above.

At this time, the zinc oxide has a ZnO concentration of about 78%, so that it can be simply applied as a raw material for dry and wet zinc smelting, but contains a large amount of impurities such as chloride and alkaline compound.

The progress of the oxidation and roasting of the crude zinc oxide is a process for producing high purity zinc oxide through a purification process in order to enhance the added value of the zinc oxide. In the purification process, zinc oxide is oxidized in a rotary kiln And oxidized and fired at 1200 to 1250 ° C.

At this time, most of the chlorides existing in the form of impurities in the midst period are volatilized mostly in the gaseous state under the high temperature oxidation condition, so that the zinc component is purified and discharged, so that the zinc oxide type 320 solid matter purified at high purity can be obtained.

The major components of recovered zinc oxide and purified zinc oxide are shown in Table 3 below.

division Zn Pb Cl K Na Fe Zinc oxide (wt%) 60 to 63 4 to 6 15-20 4 to 6 3 to 5 1-2 Refined zinc oxide (wt%) 76 ~ 78 Less than 0.01 Less than 0.01 Less than 0.1 Less than 0.01 1-2

Next, the dust-type powder is collected from the exhaust gas generated from the oxidizing roasting operation (S120).

That is, since the zinc component is refined and becomes a solid product of zinc oxide in high purity by the roasting of the crude zinc oxide, most of the chloride present in the impurity form is volatilized in the gaseous state, The powder can be collected.

The collected dust-type powder includes Pb and Zn. In the present invention, Pb and Zn can be purified with high purity.

Next, Pb and Zn in the collected dust are separated and recovered through a wet process (S130).

A general method for separating and recovering Pb and Zn in the collected dust can be roughly classified into a dry method using solid reduction volatilization and a wet method using difference in solubility of each compound.

In the dry method using solid reduction and volatilization, the method of selectively recovering Pb is the easiest and most efficient method of manufacturing Metal Pb, but is highly dependent on the content of Zn and other elements in the reduction reaction of Pb, That is, when the content of Zn and other elements is high, the efficiency is low.

 Accordingly, in the present invention, Pb and Zn in the collected dust can be separated and recovered through a wet process.

Meanwhile, the wet process using the difference in solubility can be classified according to the application of hydrochloric acid (HCl) and sulfuric acid (H ₂ SO ₄ ). At this time, the sulfuric acid (H ₂ SO ₄ ) Since an impurity solution of Na ₂ SO ₄ may be generated in the process, hydrochloric acid (HCl) is preferably used as a solvent in the wet process.

At this time, it is preferable that the pH is 2.0 to 3.0, and it is preferable to maintain 50 to 70 ° C for the reaction activation.

More specifically, a trapping powder containing Pb and Zn is added to a hydrochloric acid solution (30 to 40%) in an amount of 1 to 5 equivalents to the trapping powder to dissolve while stirring. As shown in the following reaction formula (11) (ZnCl ₂ ) 330, and the lead component in the trapping powder is lead chloride (PbCl ₂ ) (330) as shown in the following reaction formula (12).

ZnO (s) + 2HCl = ZnCl ₂ (l) + H ₂ O In the reaction formula (11)

PbO (s) + 2HCl = PbCl 2 (s) + H 2 0 -------------- Scheme 12

At this time, lead having a relatively low solubility can be recovered as a solid form of lead chloride (PbCl ₂ ), and Zn can be ionized into Zn ⁺⁺ form and recovered as a zinc (Zn) filtrate.

That is, in the present invention, the collected powder containing Pb and Zn can be separated and recovered through a wet process using the difference in solubility. In the present invention, hydrochloric acid (HCl) is preferably used as a solvent for the wet process.

Next, the separated and recovered Pb and Zn are carbonated (S140). At this time, soda ash (Na ₂ CO ₃ ) may be used for the carbonation reaction in the present invention.

In other words, PbCO ₃ (340) and ZnCO ₃ (340) are produced through desalting and carbonation process for materialization of PbCl ₂ and Zn filtrate.

At this time, as a condition of the carbonation process, the pH is preferably 8.0 to 10.0, and it is preferable to maintain 60 to 80 ° C for the reaction activation.

More specifically, PbCl ₂ in a solid form is re-slurried to add a certain amount of an aqueous solution of soda ash (Na ₂ CO ₃ ) (20% to 30%) and proceed with carbonation through dechlorination, (PbCO ₃ ).

Further, a predetermined amount of soda ash (Na ₂ CO ₃ ) aqueous solution (20% to 30%) was added to the Zn filtrate to carry out the carbonation reaction through dechlorination to produce zinc carbonate (ZnCO ₃ ) do.

PbCl ₂ (s) + Na ₂ CO ₃ = PbCO ₃ (s) + NaCl -

ZnCl ₂ (l) + Na ₂ CO ₃ = ZnCO ₃ (s) + NaCl Reaction formula (14)

As can be seen from the above reaction formulas (13) and (14), PbCO ₃ and ZnCO ₃ in solid form can be prepared through desalting and carbonation of PbCl ₂ and Zn filtrate in solid form, It is also possible to manufacture and sell as NaCl and then industrial salt.

As described above, in the secondary treatment process for treating the zinc oxide recovered in the primary treatment process according to the present invention, the oxidation and roasting of the crude zinc oxide proceeds and a zinc oxide-type solid matter Can be obtained.

In addition, the zinc component in the collecting powder containing Pb and Zn is ionized in the form of Zn ⁺⁺ and recovered easily in the form of a zinc (Zn) filtrate using the wet process through hydrochloric acid. The lead component is lead chloride (PbCl ₂ ) Can be easily recovered in solid form.

High purity PbCO ₃ and ZnCO ₃ in solid form can be produced through desalination and carbonation of PbCl ₂ and Zn filtrate, which are separated and recovered by using soda ash (Na ₂ CO ₃ ).

Hereinafter, preferred examples of the present invention will be described. However, the present invention is not limited to the following experimental examples.

[Experimental Example]

 First, as a starting material used in the present experiment, a zinc oxide product of Japanese H Company actually recovered from electric furnace steel dust was applied, and the zinc oxide was formed into a spherical pellet having a size of 1 to 5 mm.

In addition, zinc oxide in the form of a spherical pellet was subjected to oxidation roasting at 1200 ° C in a pilot test facility having a similar configuration to the actual oxidation furnace, and dust from the generated exhaust gas Was collected.

 The major components of the dust-type collecting powder are shown in Table 4 below.

division Zn Pb K Na Cl Wt% 29.34 16.10 13.14 5.02 30.30

Next, Pb and Zn in the collected dust were separated and recovered by a wet process using hydrochloric acid (HCl).

More specifically, the pH was adjusted to 2.0 in consideration of the ZnO content in the collected dust, and the temperature for the reaction activation was fixed at 60 ° C.

Further, the trapping powder containing Pb and Zn was put into a hydrochloric acid solution (30%) and dissolved while being stirred. The zinc component in the trapping powder was ionized into Zn ⁺⁺ form and recovered in the form of zinc (Zn) Was recovered as a solid form of lead chloride (PbCl ₂ ).

FIG. 4 shows the comparison of the components of the solid matter of lead chloride (PbCl ₂ ) separated and recovered from the exhaust gas trap dust through the above conditions.

4 is a view showing the components of the solid matter of the exhaust gas collecting dust and the lead chloride (PbCl ₂ ).

Referring to FIG. 4, in the case of trapped dust, Zn concentration was high and a large amount of ZnO was present. However, in the case of PbCl ₂ solid, almost no Zn component was found, It can be seen that Pb and Zn can be efficiently separated through the wet process using hydrochloric acid (HCl).

Next, PbCO ₃ and ZnCO ₃ were prepared through the desalting and carbonation process for materialization of the lead chloride (PbCl ₂ ) solids and Zn filtrate.

More specifically, the solids of lead chloride (PbCl ₂ ) were re-slurried and a certain amount of 20% soda ash (Na ₂ CO ₃ ) aqueous solution was added and the pH was adjusted to about 9.0 to carry out carbonation through dechlorination, ₃ ). Further, a predetermined amount of 20% soda ash (Na ₂ CO ₃ ) aqueous solution was added to the Zn filtrate, and the carbonation reaction was proceeded by dechlorination to prepare zinc carbonate (ZnCO ₃ ).

FIG. 3 shows the composition and phase analysis results of the lead carbonate (PbCO ₃ ) prepared above.

FIG. 5A is a view showing the components of lead carbonate (PbCO ₃ ), and FIG. 5B is a diagram showing the result of phase analysis of lead carbonate (PbCO ₃ ). First, it can be seen Referring to Figure 5b, reslurried chloride lead (PbCl ₂₎ soda ash (Na ₂ CO ₃₎ in a predetermined amount was added to the aqueous solution, the carbonation reaction is effectively been made of chlorinated lead (PbCl ₂₎ to .

Next, referring to FIG. 5A, it can be seen that PbCO ₃ produced has a high concentration of Pb and a small amount of Na remains, which can be sufficiently removed through additional washing and dehydration processes .

The composition and phase analysis results of the zinc carbonate (ZnCO ₃ ) prepared above are shown in FIG.

6A is a graph showing the composition of zinc carbonate (ZnCO ₃ ), and FIG. 6B is a graph showing the result of phase analysis of zinc carbonate (ZnCO ₃ ).

Referring to FIG. 6B, it can be seen that a certain amount of soda ash (Na ₂ CO ₃ ) aqueous solution was added to the Zn filtrate to effectively carry out the carbonation reaction of the Zn filtrate.

Next, referring to FIG. 6A, it can be confirmed that zinc carbonate (ZnCO ₃ ) produced has a high concentration of Zn.

As a result, in the present invention, the zinc component in the collecting powder containing Pb and Zn is ionized in the form of Zn ⁺⁺ and recovered easily in the form of a zinc (Zn) filtrate using the wet process using hydrochloric acid, and the lead component is lead chloride PbCl ₂ ), and the desalting and carbonation process of PbCl ₂ and Zn filtrate in the form of solids separated and recovered using soda ash (Na ₂ CO ₃ ) can be easily recovered in the form of solids. PbCO ₃ and ZnCO ₃ can be produced.

As described above, in the primary treatment process for treating the electric furnace steelmaking dust according to the present invention, zinc (Zn) is recovered as crude zinc oxide in a solid state, and the remaining components including iron (Fe) Solids in the form of clinkers are pulverized, magnetic materials are re-applied to steelmakers as Fe-sources, and non-magnetic materials can be reused as raw materials for cement.

Further, in the secondary treatment process for treating the zinc oxide recovered in the primary treatment process according to the present invention, the oxidation and roasting of the crude zinc oxide proceeds to obtain a zinc oxide-type solid product purified in high purity PbCO ₃ and ZnCO ₃ of high purity can be produced by collecting dust-like powder from the exhaust gas generated from the oxidation roasting operation.

As a result, in the present invention, when treating the electric furnace steel dust, the valuable metal contained in the electric furnace steel dust can be efficiently recovered, and an eco-friendly treatment effect can be obtained without any generation of additional secondary waste.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (6)

A step of reducing and firing the electric furnace steel dust;
Performing the reducing and firing step to separate and recover zinc and iron;
Collecting the separated and recovered zinc component with zinc oxide;
Advancing the oxidation and roasting of the zinc oxide;
Conducting the oxidizing roasting operation to obtain a first purified zinc oxide;
Collecting powder of dust type including Pb and Zn from the exhaust gas generated from the oxidizing roasting operation;
Separating and recovering Pb and Zn in the collected dust; And
And proceeding a carbonation reaction between the separated and recovered Pb and Zn,
By a step of proceeding a carbonation reaction of the separating the recovered Pb and Zn, the method of processing steel-making dust as electrical, comprising the step of obtaining a solid form of ZnCO ₃ and the solid form of the car 2 PbCO _3. The method according to claim 1,
The Zn and Pb components contained in the electric furnace steel dust are volatilized in a gaseous state and the remaining components including Fe are subjected to a reduction process to form a clinker-like solid state Wherein the method comprises the steps of: 3. The method of claim 2,
The Zn component volatilized in the gaseous state is reoxidized and cooled, and is collected in a dust collector as zinc oxide in a solid state. The solid of the clinker type is quenched, crushed, and magnetically separated Wherein the magnetic material is re-applied as a Fe-source and the non-magnetic material is reused as a raw material for cement. The method according to claim 1,
Characterized in that the Pb and Zn in the collected dust are separated and recovered by a wet process using hydrochloric acid (HCl), and the soda ash (Na ₂ CO ₃ ) is used for the carbonation reaction of the separated Pb and Zn. A method for treating steelmaking dust. 5. The method of claim 4,
Characterized in that the Zn component in the collected dust is ionized in the form of Zn ⁺⁺ and recovered in the form of a zinc (Zn) filtrate, and the Pb component is recovered in the form of a solid of lead chloride (PbCl ₂ ) Way. 6. The method of claim 5,
Wherein the zinc (Zn) filtrate is made of the ZnCO ₃ in solid form and the lead chloride (PbCl ₂ ) is made of the PbCO ₃ in solid form.

Images