KR20010008945A - Recycling method of PbS powder - Google Patents

Abstract

PURPOSE: A method for recycling PbS powder is provided to recycle by-products which is used to be waste, thereby has a high value added effect, prevent environmental pollution caused by the generation of PbS powder, obtain effects of productivity increase due to recycling of PbS powder. CONSTITUTION: A lead is recovered from PbS powder which is generated as a by-product in the recycling process of a waste lead accumulator. The PbS powder is palletized by mixing it with a binder. The lead is recovered by charging the palletized PbS powder into a blast furnace. Thereby, the working environment is improved by pelletizing PbS powder of 1 micron or less to have appropriate properties in order to recycle the lead inside the PbS powder so that available resources can be utilized, and environmental contamination according to the landfill can be prevented.

Description

Recycling method of PbS powder

The present invention relates to a recycling method of the exhaust dust to be recycled by pelletizing the dust generated as a by-product in the process of recycling the waste battery of the automobile lead.

Recycling spent batteries, which are automotive lead-acid batteries, can recover lead, an important resource, but in the process, lead generation (PbS powder) generates about 10% of the total production. These by-products, Yeonjin, currently occupy a large space because they do not have a proper treatment technology, and are left as waste that is difficult to treat.

Some treatment technology has been developed and applied to Yeonjin, but there is a lack of high value-added practical technology. As a result, the efficient treatment of the dust generated during the recycling of waste batteries is very important in terms of preventing environmental pollution, and also has the effect of resourceization by commercializing it with high added value.

The dust generated in the process of regenerating the waste battery lead acid battery into the blast furnace is a fine powder having a size of 1 μm or less, and when reloaded into the blast furnace as it is, it is difficult to be recycled due to the strong flow of air. Therefore, there is a need for a technique for reprocessing such aftershocks.

As a conventional treatment technology of Yeonjin, a waste generated as a by-product, the following method is used.

First of all, it is a method of landfilling waste, Yeonjin. This method has been common so far, but waste treatment costs are separate and adversely affected in terms of environmental pollution.

The second method is to install lead rotary furnace (dry furnace) to recover lead and recycle lead. This technology is limited in throughput and inexpensive because expensive rotary furnaces must be installed separately.

In the present invention, a technique of pelletizing fine dust in a fine state is selected without using an existing method for recycling by-product dust. That is, by mixing the fine dust and the binder capable of combining the dust evenly and molding by applying a constant pressure at a predetermined temperature, it is possible to create a dust mass having the desired physical properties.

Pelletizing lead dust with moderate strength allows charging it into existing blast furnaces, and lead pellets loaded into the blast furnace can be reprocessed without being blown up inside the blast furnace, thus recovering lead as an effective resource. Because you can.

The present invention has been made in order to solve such a conventional problem, in order to recover the lead in the dust, it is possible to utilize the effective resources by pelletizing the dust of 1 ㎛ or less to have a proper physical properties, Its purpose is to provide a method for recycling lead dust that can prevent environmental pollution.

In order to achieve the above object, the dust recycling method of the present invention is a method for recovering lead from lead (PbS powder) generated as a by-product during the recycling process of waste lead-acid batteries, wherein the dust is mixed with a binder and pelletized. After that, it is charged to the blast furnace to recover lead.

In the present invention, a pitch can be used as the binder. The pitch is preferably 5 mm or less in solid form, and the amount thereof is preferably 5 to 50 wt%.

In the present invention, a phenol resin (Phenol) can be used as the binder, the shape of the phenol resin is 1mm or less solid phase powder, the addition amount is preferably 0.5 to 30wt%.

Moreover, in this invention, it is preferable to make the said pelletization temperature into 60-200 degreeC.

In addition, the sawdust (Saw Dust) may be added to the binder at 20wt% or less.

Hereinafter, first, a process of pelletizing the dust is described.

After uniformly mixing the binder capable of binding the powder, the powder is molded at a constant pressure and a constant temperature, and then cooled by heating.

What is important here for pelletizing the dust is the selection of a binder to form the dust and have a certain strength. This is because dust is a fine powder of less than 1㎛ and hydrophobic in surface property, so it is difficult to pelletize with a general binder.

In the present invention, in the process of selecting a binder, a number of experiments were conducted in order to find an appropriate binder, and among the selected binders, an attempt was made to find an advantageous product in terms of economy. In addition to the selection of binders, process conditions were also derived to minimize the energy. In other words, it was possible to process at a low temperature if possible.

As a result of experiments in the present invention, in forming pellets, pitch and phenol resins were used as binders. Pitch is coal-based and petroleum-based, but there is no significant difference in properties, and phenolic resin may be added with a catalyst for accelerating the reactivity when forming the dust.

In addition, the pitch or phenolic resin, which serves as a binder to pellet dust, may have various characteristics and shapes in the manufacturing process, but in the case of applying the present invention, the melting point and the shape of the binder are important.

Firstly, melting point is related to working conditions and also economics. In this case, the working condition is related to the temperature at which the dust is treated at the time of pelletizing the dust, and the lower the temperature, the less energy is required, so the melting point of the binder is good. If the binder has a high melting point and a high pellet temperature, SOx gas is generated by the reaction with oxygen, which is not preferable. However, if the melting point is too low, the workability is poor and should be more than a certain degree. In conclusion, the melting point of the binder is preferably in the range of 60 ℃ to 200 ℃ as a result of the experiment.

Second is the form of a binder. The form of the binder here means whether the binder is liquid or solid. Experimental results are used to pellet the dust, a suitable form is a solid form of powder. This is because it is difficult to mix with the dust in the liquid phase. In other words, in order to pellet the dust, the binder and the dust must be mixed. In the case of liquid, there is no inconvenience in that a separate surfactant must be added because there is no wettability. In addition, the solid phase in the form of a powder rather than a liquid phase has excellent workability.

In addition, the finer the size of the powder binder is, the better, but if the size is too large, the dust and mixing are not uniform, so the size of the binder powder should be 5 mm or less for pitch and 1 mm or less for phenol. Uniform mixing and physical properties can be obtained during the process.

On the other hand, when pelletizing dust, adding sawdust as an additive improves the physical properties of the pellets. The addition of sawdust to pelletization increases the drop strength. In other words, in order to charge the pelletized smoked mass into the blast furnace, the drop strength should be excellent, but the addition of sawdust increases the drop strength, thereby improving physical properties.

In the present invention, the size of the sawdust was used as 500㎛ or less, when the size is too large, or if the amount of addition is more than about 30wt%, pores may occur inside the pellet or cracks may be caused, In case of pelletization, sufficient strength cannot be obtained due to spring back phenomenon. Therefore, the size is preferably 500 µm or less, and the amount of addition is preferably 20 wt% or less. In particular, when the weight of the pelletized lead lump is large it can be said that the additive effect of sawdust is great. That is, if the weight of the pelletized lead mass is small, the load is small when charged into the blast furnace will not be damaged when falling, but if the weight of the pellet is high when charged into the blast furnace, it is likely to break when falling.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

(Example 1 to Example 7)

In Examples 1 to 7, which are listed in Table 1, in order to pelletize the dust, mechanically mix the dust and the pitch while varying the mixing ratio of the dust and the pitch, and then charged into a mold to form and sinter. Pressure during pelletization was controlled to about 100kg / ㎠ or less, the temperature was carried out at a temperature corresponding to the melting point of the pitch. Here, we compared and described the workability during the pelletization of dust, and also stated the compressive strength of the pelletized product. In the workability section, 1) mixing of dust and binder, 2) reaction gas generation, 3) relative economic efficiency, and 4) mold release property were specified.

division Mixing ratio (wt%) Pitch type Pitch melting point (℃) (working temperature) Workability Product strength (kg / ㎠) Yanjin pitch Example 1 95 5 Solid powder (less than 5mm) 100-130 Good To 50 Example 2 90 10 〃 〃 〃 To 70 Example 3 80 20 〃 〃 〃 To 120 Example 4 80 20 〃 60-90 〃 To 60 Example 5 80 20 〃 140-170 usually To 120 Example 6 70 30 〃 100-130 Good To 130 Example 7 50 50 〃 100-130 usually ~ 140 Comparative Example 1 100 0 ­ Room temperature Good To 38 Comparative Example 2 100 0 ­ 100 〃 To 47 Comparative Example 3 100 0 ­ 200 〃 To 45 Comparative Example 4 100 0 ­ 300 Toxic Gas Emissions ~ 56 Comparative Example 5 80 20 Liquid 100-130 Poor mixing 30-100 Comparative Example 6 80 20 Solid powder (less than 5mm) 300 Poor release of toxic gas emissions 80-150 Comparative Example 7 80 20 Solid powder (less than 5mm) 60 or less Poor workability 〈50 Comparative Example 8 80 20 Solid powder (5 ~ 10mm or less) 100-130 Mixed heterogeneity 30-70 Comparative Example 9 40 60 Solid powder (less than 5mm) 100-130 Dysplastic poor economics ­

As shown in Examples 1 to 7, a pitch powder of a solid having a size of 5 mm or less is added between 5 wt% and 50 wt%, and the melting point of pitch (similar to the working temperature during pelletization) is 60 ° C. to 170 ° C. It is understood that the workability is good, and the strength of the pelletized dust is 50 kg / cm 2 or more.

(Comparative Example 1 ~ Comparative Example 9)

In Comparative Example 1 to Comparative Example 4, shown in Table 1 above is a result of a pelletization experiment with only pure dust without adding a binder. In this case, when the temperature is first worked at 300 ° C., the workability is poor because the smoke reacts with oxygen in the air to emit toxic gases such as SOx. If the temperature is between room temperature and 200 ° C, not only the product strength of the dust is 50 kg / cm 2 or less, but also the binding strength of the dust is not sufficient, so it cannot be used as it is.

Comparative Example 5 to Comparative Example 9 shown in Table 1 is the result of the experiment while adding the pitch, while changing the pitch form and melting point. The comparative example 5 is a case where a liquid phase is used instead of the pitch powder of solid content. In the case of using a liquid phase, wetting is not sufficiently performed on the surface of the dust powder having a size of 1 µm or less, and it is very difficult to mix the pitch of the dust and liquid phase. Therefore, the strength of the product varies greatly depending on the working conditions. And while using a solid pitch powder as in Comparative Example 6 and Comparative Example 7, if the temperature is too high, the workability is poor due to the release of harmful gases and poor releasability with the mold. If the temperature is too low, it is difficult to handle the mixture easily because the dust and pitch stick to the heat generated during kneading. On the other hand, as in Comparative Examples 8 to 9, when the powder size of the pitch is about 5 mm or more, it can be seen that it is important to manage the powder size of the pitch to be 5 mm or less because the powder is not uniformly mixed and mixed. . Finally, when the pitch is mixed in the dust, when the amount of the pitch is 60wt% or more, the releasability with the mold during the pelletization not only deteriorates sharply, but also is disadvantageous in terms of economics.

(Example 8 to Example 14)

Examples 8 to 14, which are shown in the following Table 2, are cases where phenolic resin is added to the dust as a binder. As shown here, when the amount of phenol resin, which is a solid powder having a size of 1 mm or less, is added in an amount of 1 wt% or more, the workability is excellent and the product strength is 150 kg / cm 2 or more. At this time, the melting point of the phenol resin is preferably managed from 60 ℃ to 150 ℃.

division Mixing ratio (wt%) Phenolic form Melting point (℃) (working temperature) Workability Product strength (kg / ㎠) Yanjin phenol Example 8 99 One Solid powder (1MM or less) 80-100 Good To 70 Example 9 95 5 〃 〃 〃 300-350 Example 10 90 10 〃 〃 〃 〉 Example 11 80 20 〃 80-100 〃 〉 Example 12 80 20 〃 60-80 〃 To 220 Example 13 80 20 〃 120-150 〃 〉 350 Example 14 70 30 〃 80-100 〃 〉 350 Comparative Example 10 95 5 Liquid 80-100 Incompatibility 50-250 Comparative Example 11 95 5 Solid powder (1 ~ 5mm) 80-100 Mixed heterogeneity 50-300 Comparative Example 12 60 40 Solid powder (less than 1mm) 80-100 Economic 〉 350 Comparative Example 13 95 5 Solid powder (less than 1mm) 60 or less Workability 〈50 Comparative Example 14 95 5 Solid powder (less than 1mm) 250 or more Poisonous emission of toxic gas To 350 Comparative Example 15 99.5 0.5 Solid powder (less than 1mm) 80-100 Good ~ 40

(Comparative Example 10-Comparative Example 15)

Specified in Table 2, Comparative Example 10 to Comparative Example 15 is the result of the experiment by adding a phenol resin to the dust, but changing the form and working temperature of the phenol resin. The comparative example 10 is a case where a liquid phase is used instead of the pitch powder of solid content. In the case of using the liquid phase, similarly to the case of using the pitch, since the mixing property with the dust is bad, the physical properties of the product were severely changed. And as shown in Comparative Examples 11 to 15, using a solid phenolic resin, if the temperature is too high can be seen to be out of the scope of the present invention because harmful gases are released and disadvantageous in terms of energy loss. If the temperature is too low, the heat generated during kneading causes the dust and phenolic resin to adhere, making the mixture difficult to handle easily. On the other hand, when the powder size of the phenolic resin is about 1mm or more, it was observed that the dust powder and mixing of the fine powder is not uniform. Finally, when the amount of phenol resin is more than 40wt%, it is disadvantageous in terms of economics. This is because phenolic resin is three times more expensive than pitch. In the case where 0.5 wt% of the phenolic resin content of solid content is added, it is preferable to add at least 0.5 wt% or more because the strength change of the product is not large.

(Example 15-Example 20)

Examples 15 to 20, which are described in Table 3 below, relate to the use of pitch or phenol resins as binders and the addition of saw dust in pelleting dust. Addition of sawdust below 20wt% in addition to the existing binder plays a role of increasing the drop strength of the pelletized lead mass.

Here, the drop strength indicates the percentage of pellets remaining unbreakable in% when free fall of 100 g of pellets from 5 m height to the alumina plate. In other words, if the drop strength of the pellets is further required, the binder pitch or phenol resin is required. Adding sawdust together with can get a good effect.

(Comparative Example 16-Comparative Example 19)

In Comparative Example 16 to Comparative Example 19, which are shown in Table 3 below, the comparative examples were carried out to comparatively compare the results shown in Examples 15 to 20, and when sawdust was not added and the amount of sawdust was added 30wt% If too much sawdust is added, defects such as cracks occur when pelletizing lead dust.

division Mixing ratio (wt%) Drop strength Yanjin pitch Phenolic Resin Saw Dust Example 15 75 20 0 5 70-80% Example 16 70 20 0 10 80-90% Example 17 60 20 0 20 〃 Example 18 90 0 5 5 80-90% Example 19 85 0 5 10 ~ 90% Example 20 75 0 5 20 ~ 90% Comparative Example 16 50 20 0 30 Crack, defect Comparative Example 17 65 0 5 30 Crack, defect Comparative Example 18 80 20 0 0 50-60% Comparative Example 19 95 0 5 0 ~ 60%

The application of the pelletizing technology to recycle the dust has the effect of recycling the by-products, which were used as wastes, to increase the added value, and can prevent the environmental pollution caused by the generation of the dust. In addition, productivity can be increased by reuse of lead, and it is possible to improve work environment and increase productivity.

Claims (7)

In the method for recovering lead from lead (PbS powder) generated as a by-product during the recycling process of waste lead-acid batteries, lead is mixed with a binder and pelletized, and then charged into a blast furnace to recover lead. Method of recycling. The method of claim 1, wherein pitch is used as the binder. 3. The recycling method according to claim 2, wherein the pitch is in the form of a solid powder of 5 mm or less, and the amount thereof is in the range of 5 to 50 wt%. The method of claim 1, wherein a phenol resin (Phenol) is used as the binder. 5. The recycling method according to claim 4, wherein the shape of the phenol resin is 1 mm or less in solid powder, and the amount thereof is 0.5-30 wt%. The method for recycling dust according to any one of claims 1 to 5, wherein the pelletization temperature is 60 to 200 ° C. The recycling method according to any one of claims 1 to 5, wherein sawdust is added to the binder at 20 wt% or less.