JP2009007622A - Method for melting lead scrap, and method for manufacturing substrate for lead battery and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for melting lead scrap while suppressing the formation of dross and also to provide a method for manufacturing a substrate for a lead battery using the melting method. <P>SOLUTION: In the method for melting lead scrap, a lead scrap receiving container 2 having a recessed longitudinal section and an opening 2a in the bottom is disposed on a lead or lead alloy melting and holding furnace 1, and lead scrap 4 is fed into the container 2 and heated and melted by a reducing flame, and the resulting melt is allowed to flow gently into molten lead 1d in the melting and holding furnace 1. In the method for manufacturing a substrate for a lead battery where the molten lead or lead alloy 1d melted in the melting and holding furnace 1 is cast into a grating substrate using a substrate casting machine 7, the lead scrap 4 generated in the substrate casting machine 7 is fed into the lead scrap receiving container 2 which has a recessed longitudinal section and an opening 2a in the bottom and disposed on the melting and holding furnace 1, where the lead scrap 4 is heated and melted by a reducing flame and the resulting melt is allowed to flow gently into the molten lead or lead alloy 1d in the melting and holding furnace 1 through the opening 2a of the lead scrap receiving container 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for melting lead debris with reduced dross generation, a method for manufacturing a lead-acid battery substrate using the melting method, and a manufacturing apparatus therefor.

  As shown in FIG. 6 (a), the lead storage battery lattice substrate 8 cast using two molds (book molds) has a runner portion 8a for introducing molten lead and positioning. As shown in FIGS. 7 and 8, the cut scraps (lead scrap) are transferred by the conveyor 3 and put into the lead scrap input chamber 1a of the melting and holding furnace 1 (see FIG. 7 and FIG. 8). It is dropped) and remelted, sent to the casting machine 7 through the molten metal transfer pipe 6, and cast again on the lattice substrate. The lead scrap 4 to be remelted includes defective substrates such as cuts (insufficient hot water), void breakage, and burnt breakage in addition to the excision waste. 7 and 8, 1d is a molten lead, and 1c is a partition plate that partitions the lead scrap charging chamber 1a and the ingot charging chamber 1b at the top.

In this way, a lot of dross floats on the surface of the melting and holding furnace 1 while repeating the remelting of the lead scrap 4. Since this dross interferes with the melting operation and also causes foreign matter to enter the product, it is periodically removed and discarded as industrial waste.
However, since this dross contains high-concentration lead of 80 to 90 mass%, discarding this dross leads to an increase in the cost of the product, and there are problems in terms of effective use of resources and environmental conservation. was there.
For this reason, various proposals (for example, Patent Document 1) have been proposed for reducing dross, but a sufficient effect has not yet been obtained.

JP-A-9-73924

The present inventors conducted various experiments in view of this situation. As a result, we found out that the main causes of dross are the oxide film present on the surface of the lead scrap, the atmosphere that is involved when the lead scrap falls, and the undulation (turbulence) of the molten metal surface when the lead scrap falls. The present invention was completed through further experiments.
An object of the present invention is to provide a lead scrap melting method capable of reducing the generation of dross, a method for manufacturing a lead-acid battery substrate using the melting method, and a manufacturing apparatus therefor.

  According to a first aspect of the present invention, a lead scrap receiving container having a concave longitudinal section and having an opening at the bottom is disposed on a lead or lead alloy melting and holding furnace, the lead scrap is supplied into the lead scrap receiving container, and the lead Dissolution of lead scraps, characterized in that the scraps are heated and melted with a reducing flame, and the lead scrap melt is gently poured into the lead or lead alloy melt in the melting and holding furnace through the opening of the lead scrap receiving container. Is the method.

  According to a second aspect of the present invention, there is provided the lead scrap melting method according to the first aspect, wherein the bottom portion of the lead scrap receiving container is allowed to enter a lead or lead alloy molten metal in a melting and holding furnace.

  A third aspect of the present invention is a method for manufacturing a substrate for a lead storage battery in which a lattice substrate is cast by a substrate casting machine using lead or a lead alloy molten metal melted in a melting holding furnace, wherein lead scrap generated in the substrate casting machine is A vertical cross section disposed on the melting and holding furnace is concave and is supplied into a lead scrap receiving container having an opening at the bottom, the lead scrap is heated and melted with a reducing flame, and the molten lead scrap is received by the lead scrap receiver. A lead storage battery substrate manufacturing method characterized by gently flowing into lead or lead alloy molten metal in a melting and holding furnace from an opening of a container.

  According to a fourth aspect of the present invention, there is provided an apparatus for producing a lead-acid battery substrate in which a molten lead or lead alloy melted in a melting and holding furnace is cast on a lattice substrate by a substrate casting machine. And a burner for heating and melting the lead scrap in the lead scrap receiving container with a reducing flame.

  A fifth aspect of the present invention is the apparatus for manufacturing a lead-acid battery substrate according to the fourth aspect, wherein the lead scrap receiving container is made of an iron-based or stainless-based metal material.

  The invention according to claim 6 is the apparatus for producing a substrate for a lead storage battery according to claim 4 or 5, wherein two or more burners are provided.

  In the lead scrap melting method of the present invention, a lead scrap receiving container having a concave longitudinal section and having an opening at the bottom is disposed on a lead or lead alloy melting and holding furnace, the lead scrap is supplied into the container, and the lead Since the scrap is heated and melted with a reducing flame, the oxide film on the surface of the lead scrap is removed. Further, since the molten lead scrap is gently allowed to flow into the molten lead in the melting and holding furnace, the atmosphere does not get involved in the molten lead in the melting and holding furnace, and the molten lead surface does not wave. Therefore, the amount of dross generated in the melting and holding furnace is reduced. Furthermore, since the lead scrap receiving container is concave, the lead scrap falling from the conveyor is efficiently and satisfactorily held in the lead scrap receiving container.

In the lead scrap melting method of the present invention, the bottom of the lead scrap receiving container is infiltrated into the molten lead in the melting and holding furnace so that the lead scrap in the lead scrap receiving container comes into contact with the molten lead quickly. Dissolve. In addition, the lead scrap receiving container can easily receive the heat of the molten lead in the melting and holding furnace, and the thermal efficiency is improved. Also, the molten lead scraps gently move to the molten lead in the melting and holding furnace through the opening, and the air entrainment and the spilling of the molten lead are better prevented.
Furthermore, even if lead scrap falls directly on the molten lead in the lead scrap receiving fuser, the entrainment of the air and the undulation of the lead molten metal are restricted in the lead scrap receiving container (see FIG. 3 (A)). Therefore, dross generation is prevented very well.

  In the method for manufacturing a substrate for a lead storage battery of the present invention, lead scrap is supplied to a lead scrap receiving container having a concave longitudinal section arranged on a melting and holding furnace and having an opening at the bottom, and is heated and melted with a reducing flame. The oxide film on the scrap surface is reduced. Also, the molten lead scrap gently flows into the lead or lead alloy molten metal (hereinafter abbreviated as lead molten metal) in the melting and holding furnace. Do not stand. Therefore, the amount of dross generated in the melting and holding furnace can be reduced, and the cost of the product can be reduced, the resources can be effectively used, and the environment can be protected.

  The lead storage battery substrate manufacturing apparatus according to the present invention has a lead scrap receiving container with a concave longitudinal section and an opening at the bottom on a melting and holding furnace of a conventional manufacturing apparatus, and is simply provided with a burner. It is excellent in terms of space and cost.

  The lead scrap receiving container can be easily formed into a shape suitable for the structure of the melting and holding furnace by being composed of an iron-based or stainless-based metal material, and the durability of the container is improved. Inexpensive.

  By providing two or more burners in the lead scrap receiving container, the lead scrap receiving container is more satisfactorily filled with the reducing flame, the oxide film on the lead scrap surface is reduced, and the dissolution rate is improved. .

An embodiment of the lead scrap melting method of the present invention will be described with reference to FIG.
Lead scrap receiving container 2 having a concave longitudinal section and having an opening at the bottom is disposed on lead or lead alloy melting and holding furnace 1 which is heated and melts and holds lead or lead alloy, and lead scrap transferred by conveyor 3 4 is supplied into the lead scrap receiving container 2, the lead scrap 4 is heated and melted by the reducing flame 5 a injected from the burner 5, and the lead scrap melt is gently poured into the molten lead 1 d in the melting and holding furnace. .

  The lead scrap 4 supplied into the lead scrap receiving container 2 starts to melt while the surface oxide is reduced in a short time by the high-temperature reducing gas combustion flame (reducing flame) 5a injected from the burner 5. . The molten lead scrap 4 flows down (inflows) from the opening 2 a into the lead scrap charging chamber 1 a of the melting and holding furnace 1.

In Figure 1, the distance d ₁ between the melt surface of the lead melt 1d of the lower end and Namarikuzu turned chamber 1a of the opening 2a of the lead waste receptacle 2 below is preferable 50 mm. If d ₁ is more than 50mm entrainment of the atmosphere by the flow落量of Namarikuzu molten metal, there is a case in which waving of the molten metal surface occurs. Here, the lead scrap container 2 is not easily damaged because it is separated from the molten lead 1d in the melting and holding furnace 1. In the figure, 1c is a partition plate and 1b is an ingot charging chamber.

  In another embodiment of the lead scrap melting method of the present invention, as shown in FIG. 2, if the bottom of the lead scrap receiving container 2 is allowed to enter the molten lead 1d in the melting and holding furnace 1, it falls from the conveyor. Since the lead scrap 4 comes into contact with the molten lead in the lead scrap receiving container 2, the lead scrap 4 is melted more quickly, and productivity can be improved and energy cost can be reduced. Further, the lead scrap molten metal only flows out into the lead molten metal 1d from the opening 2a, and does not flow down. Therefore, the lead molten metal 1d is not entrained in the atmosphere and the surface of the molten metal does not swell. The same reference numerals as those in FIG.

At this time, even if the lead scrap 4 falls directly on the molten lead in the container 2, as shown in FIG. 3 (a), the entrainment of the atmosphere and the undulation of the molten metal surface are limited in the lead scrap receiving container 2, Since the reducing flame 5a is injected, the generation of dross is suppressed.
On the other hand, in the conventional melting method, as shown in FIG. 3 (b), the lead scrap 4 falls directly into the molten lead 1d from a high position of the conveyor, so that the entrainment of the atmosphere and the undulation of the molten metal surface are within a wide range. Get up.
The penetration depth (distance from the lower end of the opening) of the lead molten metal 1d in the lead scrap receiving container 2 is preferably 30 mm or more because the effect is stable and desirable.

  In the present invention, the phrase “slowly flow the molten lead scrap into the molten lead in the melting and holding furnace” means that the atmosphere does not get involved in the molten lead in the melting and holding furnace, and the molten lead surface does not wave. Inflow or run down in a state. Specifically, it is performed by a method of sufficiently bringing the opening of the lead scrap receiving container close to the molten lead in the melting and holding furnace, a method of immersing the bottom of the lead scrap receiving container in the molten lead in the melting and holding furnace, and the like.

  In the present invention, the reducing flame for heating and melting the lead scrap includes controlling the air-fuel ratio of gas such as methane gas, ethane gas, propane gas, butane gas, city gas, etc., so that the CO concentration in the gas combustion flame is 0.5 to What was controlled to 5 mass% is applicable.

  In the present invention, the lead scrap receiving container 2 includes a box-shaped box having a V-shaped vertical section shown in FIG. 4 (a), a box-shaped box having a U-shaped vertical section shown in FIG. And those having a concave longitudinal section, such as a conical shape having a V-shaped longitudinal section shown in FIG.

  In the present invention, any material that has heat resistance and is not easily eroded by molten lead can be used as the material for the lead scrap receiving container. In particular, iron plates and stainless steel plates can be easily shaped to suit the melting and holding furnace. Recommended because it can be formed. The lead scrap receiving container is improved in durability if a release agent is applied to the surface with which the lead scrap melt or lead molten metal comes into contact.

  In the present invention, the number of burners is preferably selected according to the size of the container. When the container is small, the number of burners may be one, but when the container is large, it is desirable to use a plurality of burners so that the entire interior of the container is uniformly heated in a reducing atmosphere.

The manufacturing method of the board | substrate for lead acid batteries of this invention is demonstrated with reference to FIG.
The molten lead 1d in the melting and holding furnace 1 is introduced into the substrate casting machine 7 through the molten metal transfer pipe 6, and the lattice substrate is continuously die-cast. The grid substrate discharged from the substrate casting machine 7 is immediately cut off unnecessary portions (runner portion 8a and bottom portion 8b shown in FIG. 6) and transferred to the next electrode plate process. The cutting waste (lead scrap) 4 is transferred by the conveyor 3 and dropped into the lead scrap receiving container 2 disposed on the lead scrap charging chamber 1a of the melting and holding furnace 1 and having a concave longitudinal section and an opening 2a at the bottom. To do. As described above, the lead scrap 4 that has fallen into the container 2 is melted while the oxide film on the surface is reduced by the reducing flame (not shown), and flows down from the opening 2a into the molten lead 1d of the melting and holding furnace 1. Inflow.

  Even if the present invention is applied to a melting and holding furnace whose interior is not partitioned into a lead scrap charging chamber 1a and an ingot charging chamber 1b, the same effect can be obtained.

  Hereinafter, the present invention will be described specifically by way of examples.

A grid substrate for a lead storage battery was manufactured using the manufacturing apparatus of the present invention shown in FIG. As the lead scrap receiving container 2, a box-shaped one having a V-shaped longitudinal section shown in FIG.
The width _{W 1} of the upper open end of the Namarikuzu loading chamber 1a of the melting and holding furnace 1 is 600 mm, the length _{T 1} was 600 mm. Lead waste receptacle (manufactured by SUS430) 2 is, as shown in FIG. 4 (b), the upper end opening diameter _{W 2} 700 mm, the length L is 550 mm, the height _{h 1} was 150 mm. Three openings 2a having a width of 20 mm and a length of 150 mm were provided at the bottom of the lead scrap receiving container 2 at equal intervals. The distance _{d 1} between the bottom and lead melt 1d the surface of the opening portion 2a of the lead waste receptacle 2 was changed to three types of 20 ± 3mm, 50 ± 3mm, 60 ± 3mm. A release agent (boron nitride powder) was applied to the inner and outer surfaces of the lead scrap receiving container 2 so that dross and molten metal were easily peeled off.

  About 2 tons of lead calcium alloy was melted in the melting and holding furnace 1. The molten lead in the lead scrap charging chamber 1a was kept at a temperature of about 500 ° C. The dross on the molten metal surface was completely removed before casting was started. The inside of the lead scrap receiving container 2 was filled with a reducing flame 5 a of propane gas radiated from the burner 5. The reducing flame 5a was also discharged from the opening 2a so as to cover the hot water surface of the lead scrap charging chamber 1a. The CO gas concentration of the reducing flame 5a was automatically controlled to 2-3% by adjusting the air-fuel ratio of the burner 8. The reducing flame 5a was blue.

  Next, the molten lead 1d in the melting and holding furnace 1 is sent by a pump (not shown) through the molten metal transfer pipe 6 to the book mold casting machine 7 composed of two dies, and the lattice substrate 8 (see FIG. 6). ). The lattice substrate 8 as cast was immediately cut away from the unnecessary portions 8a and 8b, and the lattice substrate 9 cut away from the unnecessary portions was transferred to the next electrode plate process. The removed unnecessary part (lead scrap 4) was transferred onto the melting and holding furnace 1 by the conveyor 3 and dropped into the lead scrap receiving container 2. The fallen lead scrap 4 is heated and melted by the high-temperature reducing flame 5a sprayed from the burner 5 in the lead scrap receiving container 2, and the lead scrap input chamber 1a of the melting and holding furnace 1 from the opening 2a of the lead scrap receiving container 2 is melted. It flowed down into the molten lead 1d.

  The lattice substrate 10 was cast at a rate of 17 sheets per minute for 5 hours. The amount of the molten lead 1d in the melting and holding furnace 1 was kept substantially constant (about 2 tons) by appropriately introducing a lead calcium alloy ingot. The ingot was introduced by automatic control so that the molten metal level was detected by a molten metal level sensor (not shown) installed in the melting and holding furnace and the molten metal level was maintained at a constant height. Excision waste 4 generated 100 kg per hour. The dross deposited on the molten metal surface of the lead scrap charging chamber 1a was periodically collected and stored, and after the completion of casting, all the collected dross was weighed. Moreover, the dross generation rate was calculated | required by remove | dividing the said total dross amount by the amount (500 kg) of the cutting waste returned to the melt | dissolution holding furnace.

As shown in FIG. 2, the lattice substrate was manufactured by the same method as in Example 1 except that the lead scrap receiving container 2 was lowered and the bottom part was infiltrated into the molten lead 1 b, and the same investigation as in Example 1 was performed. . Note penetration depth _{d 2} of the lead scrap receptacle 2 of the lead melt 1d in was changed to three types of 20 ± 3mm, 30 ± 3mm, 60 ± 3mm.

[Comparative Example 1]
A grid substrate is manufactured by the same method as in Example 1 except that the lead scrap 4 is dropped directly from the conveyor 3 to the lead scrap input chamber 1a of the melting and holding furnace 1 using the conventional manufacturing apparatus shown in FIGS. The same investigation as in Example 1 was conducted.

  The results of Examples 1 and 2 and Comparative Example 1 are shown in Table 1.

As is apparent from Table 1, the dross generation rate in Example 1 of the present invention example was significantly lower than that in Comparative Example 1 (conventional method). In the first embodiment, the lead scrap (cutting scrap) is melted by removing the oxide on the surface by irradiating the reducing flame using a lead scrap receiving container, and the melt of the lead scrap is dissolved and held. This is because it was gently poured into the molten lead in the furnace from a short distance. Dross incidence was decreased significantly by the Nagare落distance d ₁ and 50mm or less.

In Example 2, since the bottom part of the lead scrap receiving container was infiltrated into the molten lead in the melting and holding furnace, the entrainment of the atmosphere and the undulation of the molten metal surface did not occur at all, and the dross generation rate decreased to 1.06% or less. Dross generation rate by the penetration depth d ₂ and 30mm or more were significantly reduced.

  In the above embodiment, the lead scrap receiving container (manufactured by SUS) shown in FIG. 4 (a) is used and lead scrap is melted using propane gas. ) And (c), it was confirmed that the same effect can be obtained by using other lead scrap receptacles as shown in (c) or using other gases such as butane gas and city gas.

It is side explanatory drawing which shows embodiment of the melting method of the lead scrap of this invention. It is side explanatory drawing which shows other embodiment of the melt | dissolution method of the lead scrap of this invention. It is side surface explanatory drawing which shows the motion of the lead molten metal at the time of lead waste injection | throwing-in, (A) is a case of this invention method, (B) is a case of a conventional method. (A)-(C) are respectively a plan view and an AA sectional view (longitudinal sectional view) showing an embodiment of a lead scrap receiving container used in the present invention. It is plane explanatory drawing which shows embodiment of the manufacturing apparatus of the board | substrate for lead acid batteries of this invention. (A) is a front view of the lattice substrate as cast, and (B) is a front view of the lattice substrate after unnecessary portions are cut away. It is plane explanatory drawing of the manufacturing apparatus of the conventional board | substrate for lead acid batteries. It is side surface explanatory drawing of the melt | dissolution holding furnace part of the manufacturing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Melting and holding furnace 1a Lead scrap input chamber 1b Ingot input chamber 1c Partition plate 1d Lead molten metal 2 Lead scrap receiving container 2a Opening part of bottom part of lead scrap receiving container 3 Conveyor 4 Lead scrap 5 Burner 5a Reduction flame 6 Molten metal transfer pipe 7 Substrate Casting machine 8 As-cast grid substrate 8a Runway (unnecessary part)
8b Hot water bottom (unnecessary part)
9 Lattice base plate after removing unnecessary parts (Lead storage battery substrate)

Claims (6)

  A lead scrap receiving container having a concave longitudinal section and having an opening at the bottom is arranged on a lead or lead alloy melting and holding furnace, the lead scrap is supplied into the lead scrap receiving container, and the lead scrap is heated and melted with a reducing flame. A lead scrap melting method is characterized in that the molten lead scrap is gently allowed to flow into the lead or molten lead alloy in the melting and holding furnace from the opening of the lead scrap receiving container.   The method for melting lead scraps according to claim 1, wherein the bottom of the lead scrap receiving container is allowed to enter a lead or lead alloy molten metal in a melting and holding furnace.   In a method for manufacturing a lead storage battery substrate in which a lattice substrate is cast by a substrate casting machine using molten lead or lead alloy molten metal in a melting holding furnace, lead scraps generated in the substrate casting machine are arranged on the melting holding furnace. The lead scrap is received in a lead scrap receiving container having a concave surface and an opening at the bottom, and the lead scrap is heated and melted with a reducing flame, and the melt of the lead scrap is melted into the melting and holding furnace from the opening of the lead scrap receiving container. A method for producing a lead-acid battery substrate, wherein the lead-acid battery is gently allowed to flow into a molten lead or lead alloy.   In a lead storage battery substrate manufacturing apparatus for casting lead or lead alloy melt melted in a melting and holding furnace to a lattice substrate by a substrate casting machine, lead scrap having a concave longitudinal section and an opening at the bottom on the melting and holding furnace An apparatus for producing a lead-acid battery substrate, comprising a receiving container and a burner for heating and melting lead scrap in the lead scrap receiving container with a reducing flame.   The lead-acid battery substrate manufacturing apparatus according to claim 4, wherein the lead scrap receiving container is made of an iron-based or stainless-based metal material.   The lead-acid battery substrate manufacturing apparatus according to claim 4 or 5, wherein two or more burners are provided.