KR101863086B1 - Manufacturing method of crude copper and pig iron from low-grade copper sludge - Google Patents

Abstract

The present invention relates to a method for manufacturing crude copper and pig iron from low-quality copper sludge. One embodiment of the present invention comprises: a step (a) of mixing low-quality copper sludge, coke, silica and quicklime; and a step (b) of subjecting the mixed material to reduction melt treatment in a submerged arc furnace and separating generated slag.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing coarse and fine iron from low-grade copper sludge,

More particularly, the present invention relates to a method for reducing and melting a low-grade copper sludge by adding coke, silica, and quicklime to the low-grade copper sludge.

Copper-containing sludge is produced annually in the process of printing circuit board processing, etching, plating, etc. However, only some high-quality sludge is recycled at some large smelting plants using a dry smelting process. Low grade copper sludge with a copper content of less than 25 wt% is mostly sold or landfilled, and resource leakage and environmental pollution are intensifying.

Copper sludge generated in plating and etching process of printed circuit board contains about 20 wt% of iron in iron oxide form. However, in the dry smelting process, most of it is discharged as slag, which is used only as an additive for building materials, and most of it is landfilled and disposed of.

Some domestic companies have recovered valuable metals using copper smelting method using copper-containing sludge. However, there is a problem of recovery rate due to limitation of smelting process and disadvantage of securing raw material compared to domestic large-scale dry smelter. In addition, when the low-grade copper sludge is treated in a domestic large-scale dry smelter, there is a disadvantage in terms of cost due to prolonged lead time until the recovery of copper and other valuable metals.

Submerged Arc Furnace (SAF), unlike an arc furnace of a conventional dry smelter, is a method in which a carbon electrode rod is directly immersed in a molten metal to melt the raw material by the heat of the input raw material, It is capable of high temperature operation, has less facility size and energy consumption compared to existing dry smelter, and has the advantage of minimizing lead time. However, there is still a lack of research on the technology for recovering valuable metals from low grade sludge at a high recovery rate.

As a related patent, a method and a device for recovering copper from copper sludge disclosed in Korean Patent Publication No. 10-1797913 and a method for producing copper from low-grade copper sludge disclosed in Korean Patent Publication No. 10-1717738 have.

Korean Patent Registration No. 10-1797913 Korean Patent Registration No. 10-1717738

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the limitations in treating copper sludge by conventional wet chemical smelting alone.

Another object of the present invention is to process low-grade copper sludge containing predetermined iron and copper through a submerged arc furnace, thereby effectively recovering the coarsening and pig iron.

In order to accomplish the above object, one aspect of the present invention provides a method for producing a sludge, comprising: (a) mixing low grade sludge, coke, silica and quicklime; And (b) subjecting the mixed material to a reduction melt treatment in a submerged arc and separating the generated slag.

In one embodiment, the low grade copper sludge of step (a) may be calcined at a temperature of 400-500 ° C.

In one embodiment, the low grade copper sludge in step (a) may be a by-product of the PCB plating or etching process.

In one embodiment, the low-level copper sludge in step (a) may have an iron content of 5-25 wt% and a copper content of 5-25 wt%.

In one embodiment, the mixing of step (a) may comprise mixing 9 to 12 parts by weight of the coke with respect to 100 parts by weight of the low grade copper sludge; 33 to 41 parts by weight of the silica; And 20 to 28 parts by weight of the quicklime.

In one embodiment, the reducing and melting treatment of step (b) may be performed at a temperature of 1470 to 1600 ° C.

In order to achieve the above object, another aspect of the present invention is a method for manufacturing a printed circuit board, comprising the steps of (0) drying and calcining a by-product, which is generated in a printed circuit board processing step and contains 5-25 wt% ; (1) mixing the calcined by-product, coke, silica and quicklime; And (2) subjecting the mixed material to a reduction melt treatment in a submerged arc and separating the generated slag. The present invention also provides a method for collecting and recovering pig iron from a printed circuit board processing by-product.

In order to accomplish the above object, another aspect of the present invention is a method for producing sludge, comprising: mixing 8-13 weight parts of cokes relative to 100 weight parts of low grade copper sludge; 33 to 41 parts by weight of silica; And 20 to 28 parts by weight of quicklime from low-grade copper sludge through reduction melting of submerged arc.

According to one aspect of the present invention, by treating the low-grade copper sludge using a submerged arc, it is possible to overcome limitations in treating the copper sludge with conventional wet-smelting alone and to overcome the limitation of iron recovery in dry- have.

 In addition, it is possible to recover useful resources such as copper and iron and other valuable metals (Au, Ag, etc.) at a high recovery rate, thereby minimizing resource leakage and environmental pollution in comparison with the sale or landfill of existing low- There is an effect that can be.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

FIGS. 1 to 3 are schematic views showing an example of a method of manufacturing roughening and pig iron from low grade copper sludge according to an embodiment of the present invention.
FIG. 4 is a photograph of the coarse and pig iron produced in Example 1 of the present invention separated and cooled. FIG.

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

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving it will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

It should be understood, however, that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. To fully inform the inventor of the category of invention. Further, the present invention is only defined by the scope of the claims.

Further, in the following description of the present invention, if it is determined that related arts or the like may obscure the gist of the present invention, detailed description thereof will be omitted.

One aspect of the present invention is

(a) mixing low grade copper sludge, coke, silica and quicklime (S10); And

(b) subjecting the mixed material to a reduction melt treatment in a submerged arc and separating the generated slag (S20).

Hereinafter, a method of manufacturing roughening and pig iron from low grade copper sludge according to an embodiment of the present invention will be described for each step.

In the method of manufacturing roving and iron from low grade copper sludge according to an embodiment of the present invention, step (a) (S10) mixes low grade copper sludge, coke, silica and quicklime.

In the low-level copper sludge treatment method disclosed in Korean Patent Publication No. 10-1717738, a step of adding a binder and / or a flux to produce a coarse sludge from low-grade copper sludge, Respectively. According to one embodiment of the present invention, the iron component contained in the low-grade copper sludge can be recovered in the form of pig iron by using coke, silica, and quicklime, and an additional added value can be created.

The low grade copper sludge in step (a) may be a by-product of the PCB plating or etching process.

The low-grade copper sludge of step (a) is preferably subjected to a calcination treatment at a temperature of 400-500 ° C. If the firing temperature is less than 400 ° C, there is a possibility that the organic matter, moisture and impurities that may be contained in the sludge may not be effectively removed. If the firing temperature is higher than 500 ° C, the removal of organic matter, moisture and impurities in the sludge Excessive energy waste can occur.

The calcination treatment in the step (a) may be carried out for 1 to 4 hours, preferably for 2 to 3 hours. If the calcination treatment time is less than 1 hour, organic matter may remain in the calcined low-grade copper sludge, and if the calcination treatment time exceeds 4 hours, excess energy waste in removing organic matter, moisture and impurities of the low- May occur.

The firing process in the step (a) may be efficient in treating the organic matter, moisture and impurities in the sludge if performed in the rotary baking furnace, but is not limited thereto.

Through the calcination treatment in the step (a), damage of the refractory material, fume and dust loss due to the organic matter in the sludge can be minimized.

The low grade copper sludge in the step (a) may include iron oxide and copper oxide, and the iron content may be 5-25 wt% and the copper content may be 5-25 wt%.

The mixing of the step (a) may be performed by mixing the low-grade copper sludge with 100 parts by weight

9 to 12 parts by weight of the coke;

33 to 41 parts by weight of the silica; And

20 to 28 parts by weight of the quicklime,

In comparison with 100 parts by weight of the low grade copper sludge

9 to 12 parts by weight of the coke;

35 to 39 parts by weight of the silica; And

And 22 to 26 parts by weight of the quicklime.

If the coke is added in an amount of less than 9 parts by weight in the mixing of the step (a), the reduction reaction of copper oxide and iron oxide contained in the low-grade copper sludge may not be sufficiently performed. If the coke is added in an amount exceeding 12 parts by weight , There is a fear that the carbon content of iron produced in the subsequent step becomes excessive and the metal recovery rate may be lowered.

If the silica is added in an amount of less than 33 parts by weight and more than 41 parts by weight in the mixing of the step (a), the melting point of the slag generated during the subsequent reduction and melting may increase, thereby failing to effectively separate the silica.

In the mixing of step (a), if the fresh lime is added in an amount of less than 22 parts by weight and more than 26 parts by weight, the melting point of the slag generated during the subsequent reduction and melting is further increased to make it difficult to separate the slag, The content may be increased.

That is, it is preferable that the mixing in the weight ratio range in the step (a) is performed in the subsequent reduction melting treatment and slag separation.

In the method of manufacturing roots and pig iron from low grade copper sludge according to an embodiment of the present invention, step (b) (S20) reduces and melts the mixed material in a submerged arc and separates generated slag.

Unlike the arc furnace used in the top submerged lance (TSL) and steelmaking processes of the smelter, the submerged arc of the step (b) is immersed in the resistance heat of the input raw material, Thereby melting the raw material.

In the reducing and melting process of the step (b), the material mixed in the step (a) may be first stored in the raw hopper, and then the mixed material may be introduced into the submerged arc. The low-grade copper sludge in the mixture is melted by the arc heat generated from the carbon electrode of the submerged arc, and when the molten metal is formed, the carbon electrode rod is immersed in the molten metal to melt the sludge by resistance heat.

The reduction reaction with coke in the reduction melting at the step (b) can be represented by the following reaction formula.

[Reaction Scheme 1]

2CuO + C? 2Cu + CO ₂

[Reaction Scheme 2]

_{2Fe 2 O 3 + 3C → 4Fe} + 3CO 2

The reaction equation 1 is the reduction reaction of copper oxide contained in the low-grade copper sludge, and the reaction formula 2 is the reduction reaction of iron oxide contained in the low-grade copper sludge.

The reduction melting treatment in step (b) may be performed at a temperature of 1470 to 1600 ° C, preferably at a temperature of 1470 to 1550 ° C. If the reduction melting temperature is lower than 1470 DEG C, the viscosity of the slag may be considerably lowered, which may result in a problem that it can not be effectively separated in a subsequent stage. If the reduction melting temperature is higher than 1600 DEG C, Waste may occur.

The reduction melting treatment in the step (b) can be performed for 2-6 hours, and the reduction of the metal in the sludge and the melting of the slag can be effectively performed within the time range described above.

Through the reduction and melting in the step (b), the iron oxide is reduced to pig iron and the copper oxide is reduced to coarse iron among low-grade copper sludge raw materials. Other valuable metals may be employed in ferrous or copper melts.

The pig iron or coarse obtained through the step (b) can be separated and refined into a valuable metal, iron and copper by wet smelting. Concretely, if the wet-type refining obtained in the step (b) is slightly refined, high-purity copper and iron can be recovered and a slurry containing a valuable metal can be obtained. The slime can be separated and purified by a wet leaching process, such as gold, silver, palladium and platinum.

According to one aspect of the present invention, there is provided a method for manufacturing roots and pig iron from low-grade copper sludge, comprising the steps of (a) and (b) And recovery rate of copper and iron can be 97% or more.

In another aspect of the present invention,

(0) drying and calcining a by-product, which is generated in the printed circuit board processing step and contains 5 to 25 wt% of iron and 5 to 25 wt% of iron (S0);

(1) mixing the sintered by-product, coke, silica and quicklime (S1);

(2) reducing and melting-treating the mixed material in a submerged arc and separating generated slag (S2) from the printed circuit board processing by-product.

The by-product of the step (0) may be the same as the low-level copper sludge described above.

The steps (1) and (2) may be as described in steps (a) and (b).

In another aspect of the present invention,

100 parts by weight of low-grade copper sludge

8 to 13 parts by weight of coke;

33 to 41 parts by weight of silica; And

And 20 to 28 parts by weight of quicklime from the low-grade copper sludge through reduction melting of the submerged arc.

The composition preferably comprises

100 parts by weight of low-grade copper sludge

9 to 12 parts by weight of coke;

35 to 39 parts by weight of silica; And

22 to 26 parts by weight of quicklime.

Problems that may occur when the weight ratio of each component is out of the range may be as described in the mixing of step (a).

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following examples and experimental examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

&Quot; Example 1 " Pig iron and coarse recovered from low grade sludge

(0): Low-grade copper sludge (containing 21.89 wt% of iron and 20.08 wt% of copper) as a by-product of plating and etching process of printed circuit board was dried and calcined in a rotary kiln at 450 ° C for 2 hours.

(1): 52.7 g of coke, 180 g of silica, and 120 g of burnt lime were mixed with 500 g of the low-grade copper sludge subjected to the calcination treatment.

(2) The mixed material was introduced into a submerged arc furnace, subjected to reduction melting treatment at a temperature of 1500 캜 for 4 hours, and slag was separated by tapping.

&Quot; Experimental Example 1 " Sludge before treatment, little bit after treatment and slag content analysis

In Example 1, the components of the low-grade sludge before the reducing and melting treatment, the components after the reducing and melting treatment, and the components and the contents of the slag were measured by ICP and XRF analysis. The results are shown in Tables 1 and 4 Respectively.

Referring to Table 1, about 10.4 parts by weight of cokes, 36 parts by weight of silica and 24 parts by weight of quicklime were added to 100 parts by weight of low-grade copper sludge, and then subjected to reduction melting treatment to a predetermined temperature through a submerged arc, Was easily recovered. The iron content of the recovered pig iron was 95 wt%, and the recovery rate of iron from the raw material was about 97.4%. The recovered coarse grains were 98 wt%, and the recoveries from the raw materials were about 97.5%.

Referring to FIG. 4, it can be seen that the coarse and the pig iron produced through Example 1 are classified by the specific gravity difference.

The present invention is not limited to the above-described embodiments, but various modifications may be made without departing from the scope of the present invention.

Therefore, the scope of the present invention should not be construed as being limited to the embodiments described, but should be determined by equivalents to the appended claims, as well as the following claims.

It is to be understood that the foregoing embodiments are illustrative and not restrictive in all respects and that the scope of the present invention is indicated by the appended claims rather than the foregoing description, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

Claims (8)

(a) mixing low grade copper sludge, coke, silica and quicklime; And
(b) subjecting the mixed material to a reduction melt treatment in a submerged arc, and separating the generated slag,
The mixing of the step (a) may be performed by mixing 9 to 12 parts by weight of the coke with respect to 100 parts by weight of the low-grade copper sludge; 33 to 41 parts by weight of the silica; And 20 to 28 parts by weight of the quicklime are added to the roasted sludge.
The method according to claim 1,
The low grade copper sludge in the step (a)
Wherein the sludge is calcined at a temperature of 400-500 캜.
The method according to claim 1,
The low grade copper sludge in the step (a)
Wherein the sludge is a by-product of plating or etching of printed circuit boards.
The method according to claim 1,
The low grade copper sludge in the step (a)
Wherein the iron content is 5-25 wt% and the copper content is 5-25 wt%.
delete The method according to claim 1,
The reducing and melting treatment in the step (b)
Characterized in that the process is carried out at a temperature of 1470-1600 < 0 > C.
(0) drying and calcining a by-product generated in a printed circuit board processing step and containing 5 to 25 wt% of iron and 5 to 25 wt% of copper;
(1) mixing the calcined by-product, coke, silica and quicklime; And
(2) subjecting the mixed material to a reduction melt treatment in a submerged arc, and separating the generated slag,
The mixing of the step (1) may include mixing 9 to 12 parts by weight of the coke with respect to 100 parts by weight of the by-product; 33 to 41 parts by weight of the silica; And 20 to 28 parts by weight of the quicklime.
100 parts by weight of low-grade copper sludge
8 to 13 parts by weight of coke;
33 to 41 parts by weight of silica; And
And 20 to 28 parts by weight of quicklime. ≪ RTI ID = 0.0 > 21. < / RTI >

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