KR20190077486A - Method for manufacturing active material for lead-acid battery - Google Patents

Abstract

The present invention provides a manufacturing method capable of efficiently producing a podium having a high degree of punching. A first heating step of heating the lead oxide and the lead containing metal lead as main components at a first heating temperature to oxidize the lead metal in the lead metal is performed and the fired material heated in the first heating step is heated at a second heating temperature , And a second heating process is performed to soften the melt. In the firing before heating in the first heating step, a product produced by grinding a metal lead by a ball mill method is used. The first heating temperature is adjusted to be equal to or lower than the second heating temperature.

Description

Method for manufacturing active material for lead-acid battery

The present invention relates to a method for producing an active material for lead-acid batteries for producing a lead edge which is an active material for lead-acid batteries.

BACKGROUND ART In the field of lead-acid batteries, pads are used for active material in order to increase the conversion efficiency of lead-acid batteries (Patent Literature 1 and Patent Literature 2). The podium is obtained by heating or firing this pellet, using the pellet (lead monoxide containing metal lead) as a raw material. BACKGROUND ART [0002] Conventionally, a batch-type heating apparatus in which the production management is relatively easy is used for the heating of fines. However, the batch type heating apparatus is not suitable for mass production of the podium, and therefore does not follow the demand for increasing the production amount of the podium.

Therefore, in order to increase the production amount of the edge, it is preferable to use a continuous heating apparatus. However, the continuous heating apparatus is complicated in the structure of the apparatus and long in the production line, so that it is difficult to control the heating temperature and the like. In addition, since the throughput of the pellet which can be used as the raw material of the pellet is increased, the metal lead contained in the pellet is relatively increased. As a result, the oxidation reaction of the metal lead becomes severe due to heating for plowing, and the temperature in the apparatus tends to increase. For this reason, when a continuous heating apparatus is introduced, there is a problem that the plowing degree is lowered due to generation of lead oxide which is hardly plowed and melting of metal lead or the like, and the processing time for plowing is prolonged.

In order to solve such a problem, when mass production of a podium is carried out by a continuous heating apparatus, a pellet having a degree of oxidation higher than that of a conventional pellet (a content of a metal lead is small) is used as a raw material for a pellet. For example, as shown in Fig. 3, first a high-oxidation rate is generated by the so-called button port method (ST101), the stale is heated as a raw material of the edge (ST102) , And crushing and sizing it (ST104) to produce a podium.

Japanese Patent Laid-Open Publication No. Hei 10-270029 (paragraphs [0030], [0031], etc.) Japanese Patent Application Laid-Open No. 2009-187776 (paragraph [0023], etc.)

However, when mass production of the podium is attempted using a high-oxidation pellet as a raw material, there is a tendency that lead monoxide, which is difficult to be panned in the pellet, tends to be generated during manufacture of the pellet. Even if it is intended to mass-produce the podium by using the puddle containing the lead monoxide, which is difficult to be puddled, it takes time to puddle, and the production amount of the puddle per unit time can not be increased. Even if the content of lead in the flux is small, if the lead is heated in a large amount by a continuous heating device, the throughput of the lead becomes relatively large and a serious oxidation reaction occurs during heating, and the temperature in the heating device becomes high. As a result, a part of the metal lead is melted and the grain size of the flux is uneven, so that the plowing is not sufficiently progressed, and the plowing degree is rather lowered. For this reason, even when a high-oxidation rate frying material is used as a raw material for a pellet when introducing a continuous heating apparatus, the amount of pellets can not be increased as a result, so the production amount of pellets can not be sufficiently increased.

It is an object of the present invention to provide a method of manufacturing an active material for lead-acid batteries, which can increase the production amount of the active material (podium) while maintaining the performance of the active material for the lead-acid battery (high degree of punching).

A method for producing an active material for a lead-acid battery to which the present invention is to be improved is a method for producing a podium used as an active material for a lead-acid battery by heating a pellet containing lead monoxide and lead as a main component. The manufacturing method of the present invention includes a first heating step and a second heating step. In the first heating step, the frit is heated at the first heating temperature to oxidize the metal lead in the frit. Further, in the second heating step, the fired material heated in the first heating step is heated at the second heating temperature to soften it. As the frit before heating in the first heating step, the frit produced by grinding the metal lead by the ball mill method is used. The first heating temperature in the first heating step is set to be equal to or lower than the second heating temperature in the second heating step.

In the production method of the present invention, it is preferable to heat preliminary firing (hereinafter also referred to as preliminary heating) in the first heating step, before the frying is performed by heating in the second heating step, the relatively low degree of oxidation (the content of the metal lead is relatively high) The metal lead in the tin is oxidized as much as possible so that the temperature of the device can be prevented from rising due to the rapid oxidation reaction of the metal lead in the second heating step. Therefore, it is possible to prevent the generation of lead monoxide, which is difficult to be dialed in the second heating step. Here, " difficult to be padded " means that the padding of the paddles is low, or that the padding takes a comparatively long time to paddle the paddle, though the padding is padded. As factors that are difficult to be pioneered, it is preferable that a large amount of lead pyrogenic lead (also referred to as? -Type lead monoxide or? -PbO) is contained in the lead, or lead monoxide or lead in the lead is melted and bonded, Particles, and the specific surface area of the fines is small.

On the other hand, the fines produced by grinding the metal lead by the ball mill method tend to generate friable purity. Here, " easy to pendent " means that the pendant is pendant in a relatively short time. By preliminarily heating the pelletizable pellet prior to the heating of the pelletization as in the present invention, the pelletization can be achieved in a short time without lowering the pelletization degree. Therefore, by using the manufacturing method of the present invention, it is possible to shorten the processing time for the pendantization while maintaining the pendant degree, and to increase the production amount of the pendent per unit time (hereinafter referred to as the basic effect of the present invention ).

Further, in order to obtain the basic effect described above, a frit having an oxidation degree of 63% or more may be used. The inventors confirmed that the oxidation degree of the fines produced by milling the lead of the metal by the ball mill method was in the range of 63% or more. Therefore, it is not limited to the one produced by grinding the metal lead by the ball mill as the firing before heating in the first heating step, and the fines adjusted to the oxidation degree of 63% or more can be used.

In addition, when the oxidation degree of the fines is not 63%, the content of the metal lead in the fines is large, so that the oxidation reaction occurs severely in the first heating step, The metal lead is easily melted. In this state, if the process proceeds to the second heating process, the heating time becomes long (as a result, the production amount of the podium per unit time decreases), and the degree of pendant of the obtained podium becomes low.

The first heating temperature in the first heating step is preferably adjusted to 300 to 330 占 폚. By adjusting the first heating temperature to this temperature range, the basic effect of the present invention can be reliably obtained. If the first heating temperature does not reach 300 deg. C, the oxidation of the fines is not sufficient and the metal lead remains in the fines, so that the oxidation reaction becomes severe in the second heating step and the temperature in the apparatus becomes high. As a result,? -Type lead monoxide is liable to be generated, the lead of the metal is easily melted, and the degree of plowing is lowered. On the other hand, when the first heating temperature is higher than 330 ° C, the fines cause an oxidation reaction so that the β-type lead monoxide tends to be easily produced, and the metal lead is liable to be melted. In this state, even if the process proceeds to the second heating step, the heating time becomes longer (i.e., the production amount of the edge portion per unit time decreases) and the degree of edge peening becomes low.

Heating in the first heating step may be performed while stirring the frit. In the present specification, the term " stirring " means that the interior of the heating furnace for performing the first heating step is rotated at a constant number of revolutions. When the heating is performed in the first heating step while stirring as described above, the oxidation degree of the fines can be increased and the production amount of the podium per unit time can be increased.

The first heating step can be carried out using a heating furnace. In this case, the heating furnace may be divided into three areas including the first segment, the second segment and the third segment. For example, the first segment constitutes an inlet portion into which the flue is injected into the furnace, the second segment continues to the first segment and constitutes the central portion of the heating furnace, and the third segment constitutes the 2 segments, and constitutes an outlet portion for discharging the frit to the outside of the heating furnace. The first heating temperature is set so that the heating temperature in the first segment is not lower than the heating temperature in the second segment and the heating temperature in the third segment. Specifically, after the first heating step is divided into these three segments, the heating temperature is set to be high in advance, assuming that the temperature is lowered by the introduction of the fuels in the vicinity of the inlet of the first heating step. By performing such temperature adjustment in the first heating step, the heating temperature can be kept constant throughout the first heating step. Therefore, the oxidation reaction of fines in the first heating step can be performed stably.

The degree of oxidation of the flakes is preferably adjusted to not less than 67%. By using the frit having the oxidation degree in this range, the processing time for the plowing can be shortened, and the plowing degree can be increased while increasing the production amount of the plowing.

The second heating temperature is preferably adjusted to 375 to 480 캜. This temperature range is a temperature range suitable for plowing the frit heated in the first heating step. If the second heating temperature does not reach 375 占 폚, there is a possibility that the plowing may not sufficiently proceed. If the second heating temperature exceeds 480 캜, the oxidation reaction of fines becomes excessively excessive, the lead monoxide tends to be easily converted into β, and the lead metal tends to be melted together with the remaining metal lead. As a result, there is a fear that it takes time to make the purity of the puddle, and that the puddle degree obtained also becomes low.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a process flow of a method for producing an active material for lead-acid batteries according to the present invention.
Fig. 2 shows a schematic configuration of the first heating step in the embodiment of the present invention.
Fig. 3 shows a schematic configuration of the second heating step in the embodiment of the present invention.
Fig. 4 shows a process flow of a conventional method for producing an active material for lead-acid batteries.

Hereinafter, embodiments of the present invention will be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a process flow for manufacturing a lead edge to be a material of a positive electrode active material for a lead-acid battery as an embodiment of the method for producing an active material for lead-acid batteries of the present invention. In Fig. 1, first, the plow serving as the raw material of the podium is prepared. Specifically, in the tin generation step, the ingot of the metal lead is pulverized by a ball mill to produce a tin (step ST1). The milling with the ball mill is carried out so that the degree of oxidation of the obtained frit is 63 to 78%.

The fraction prepared in step ST1 is heated at the first heating temperature in the first heating step (step ST2). The heating in the first heating step is heating (preliminary heating) which is carried out preliminarily for the second heating step (main heating) to be described later. In the first heating step, the first heating temperature is adjusted to a temperature in the vicinity of the melting point of lead (300 to 330 占 폚), so that lead monoxide and metal lead in the lead are converted into lead monoxide (? , Or the frit is heated so that the lead metal or lead monoxide in the frit is not melted.

(Hereinafter, referred to as preheating completed fraction) is heated at the second heating temperature in the second heating process at step ST2 (step ST3). Heating in the second heating process is intrinsic heating (main heating) to soften the frit. In the second heating step, the second heating temperature is adjusted to the temperature range from the temperature (375 ° C) near the melting point of the lead to the temperature (480 ° C) at which the melting point of the lead does not greatly exceed the melting point, The pellet is heated so as not to be dialed by the? -Type monodisperse lead that is difficult to be panned, or the lead metal or the like in the pellet is not melted. Further, in the second heating step, a continuous heating furnace (multistage heating furnace), which will be described later, capable of mass production of a podium, is used as a device for performing heating (main heating) for softening the frit.

In this example, preliminary heating by the first heating step is followed by main heating by the second heating step. Between the first heating step and the second heating step, More than two times. By carrying out the preheating twice or more in this manner, it is possible to make the plowing (the plowing degree improvement and the plowing production amount increase) more efficient.

The finned fraction (hereinafter referred to as the already-heated fraction) that has been heated in step ST3 is aged in a silo (not shown) in the aging step (step ST4).

The main finishing finished finishing step in step ST4 is pulverized using a pulverizer (including a crushing hammer and a punching metal) (not shown) in the crushing and sizing step, and the particle diameters are aligned (step ST5). Specifically, the presently completed frit is crushed by a crushing hammer, and the crushed frit is set by a punching metal.

Among the steps ST1 to ST5, the first heating step of step ST2 further includes the configuration shown in Fig. Fig. 2 is a diagram showing a schematic configuration of a preheating apparatus for executing the first heating step. Fig. The preheating apparatus 1 includes a heating furnace 3 and a hollow drum 5 disposed inside the heating furnace and having open ends at both ends thereof. And a heater (not shown) for heating the drum 5 in the circumferential direction of the drum 5 is disposed. In this example, the first heating temperature corresponds to the surface temperature (heater temperature) of this drum. Although the cylindrical drum 5 is used in the main portion of the heating furnace 3 in this example, the drum may be of any shape as long as the condition for preheating the frit can be ensured, A conveyor type heating furnace may be used.

At one end (5a) of the drum (5), a charging portion (7) for charging the raw material is provided. In the charging section 7, the flue prepared as a raw material is supplied from the charging port 7a to the drum 5. At the other end (5b) of the drum (5), a take-out portion (9) for taking out the preheated frit is provided. In the take-out unit 9, the preheating completed flue is taken out from the take-out opening 9a and sent to the second heating step.

The take-out portion 9 is provided with an intake port 11 for sending air into the drum 5 in order to lower the temperature in the drum 5 and to supply oxygen necessary for the oxidation reaction of the fuels. On the other hand, the inlet portion 7 is provided with a discharge port 13 for discharging the air supplied from the inlet port 11 of the takeout portion 9 to the outside and discharging the dust generated in the drum 5 to the outside when the frit is heated ). Air sucking and discharging devices through the intake port 11 and the exhaust port 13 are performed by the fans 15 and 17. The dust discharged from the discharge port 13 is recovered by a dust collector (not shown).

The inside of the drum 5 is configured to rotate. By rotating the inside of the drum 5 at a constant number of revolutions, the preheating can be performed while stirring the fractions. That is, agitation of the frit is performed by rotating the drum 5 to be preheated at a constant number of revolutions.

The drum 5 in the heating furnace 3 is provided with an inlet portion 5a (first segment of the heating furnace), a central portion 5b And the outlet portion 5c (the third segment of the heating furnace). In the central portion 5b of the drum 5, a partition plate 19 is provided at a position that does not disturb the heating of the frit. The partition plate 19 is formed in such a manner that the air supplied from the inlet port 11 is discharged from the discharge port 13 through the inside of the drum 5 (the outlet portion 5c to the inlet portion 5a) And has the function and effect of promoting the oxidation by supplying oxygen (air) sufficient for the prevention of the excessive heat discharge and the fines. Thereby, in the drum 5, the temperature of the inlet portion 5a is adjusted so as not to become lower than the temperature of the center portion 5b and the outlet portion 5c. Thermometers 21, 23 and 25 for measuring the temperatures of the respective portions 5a to 5c are provided in the respective portions 5a to 5c of the drum 5, respectively.

In the first heating step of this example, the single-stage heating furnace shown in Fig. 2 is used. However, according to the production amount of the podium stage, a multi-stage heating furnace in which two or more heating furnaces of Fig. 2 are vertically overlapped, .

Among the steps ST1 to ST5, the second heating step of step ST3 further includes the configuration shown in Fig. Fig. 3 is a view showing a schematic configuration of the present heating apparatus 2 for executing the second heating step (main heating). The heating apparatus 2 includes a heating furnace 4 and a hollow drum 6 disposed in the heating furnace 4.

In the heating furnace 4, a heater (burner) 8 is disposed at the bottom portion, and a discharge port 28 for discharging the exhaust gas or heat in the furnace to the outside.

The drum 6 is also provided with four partial drums (first partial drum 12, second partial drum 14, third partial drum 16, and fourth partial drum 18) Consists of. The inside of each of the partial drums 12, 14, 16, 18 is configured to rotate. The two partial drums lined up and down communicate with each other through communication passages (first communication passage 20, second communication passage 22 and third communication passage 24) extending upward and downward.

The first partial drum 12 is provided with a charging port 26 for charging the preheated fraction LP in the first heating process. The inlet 26 is disposed in communication with the outlet 9a of the preheating apparatus shown in Fig. The fourth partial drum 18 is provided with a blow-out port 28 for extracting the generated edge RL after completion of heating in the second heating process.

In this embodiment, the feed LP fed from the feed port 26 is heated while being heated from the first partial drum 12 to the fourth partial drum 18, and the generated edge is taken out from the outlet 28. At this time, the first partial drum 12 is heated to 380 to 440 占 폚, the second partial drum 14 to 410 to 440 占 폚, the third partial drum 16 to 420 to 460 占 폚, the fourth partial drum 18, Lt; RTI ID = 0.0 > 440 C < / RTI > Further, the second heating temperature corresponds to the maximum temperature among the surface temperatures of the partial drums 12, 14, 16, and 18.

Although a cylindrical partial drum is used in this example, the shape of the partial drum may be any shape as long as the conditions enabling the main heating of the fractions can be secured, and a conveyor type heating furnace may be used instead of the drum type .

Example

Hereinafter, the effects of the present invention in comparison with the comparative example will be described. Table 1 shows the conditions and results of Examples 1 to 20 and Comparative Examples 1 to 6.

(Example 1)

The oxidation degree of the flux (raw material) is set to 63%, and the heating temperature in the first heating step (preliminary heating) is set to 300 캜 and the heating temperature in the second heating step (main heating) is set to 450 캜 Respectively. In the preliminary heating, a two-stage heating furnace was used, and in this heating, a continuous (four-stage) heating furnace was used.

(Examples 2 to 8)

The same conditions as in Example 1 were set, except that the degree of oxidation of the fines was 65%, 67.5%, 69.5%, 74.5%, 76.5%, 78% and 82%.

(Example 9)

And the heating temperature in the first heating step (preliminary heating) was set to 300 ° C.

(Examples 10 to 13)

The same conditions as in Example 9 were set, except that the heating temperatures in the first heating step (preliminary heating) were changed to 310 ° C, 320 ° C, 325 ° C and 330 ° C.

(Examples 14 to 16)

The same conditions as in Example 9 were set, except that the heating temperatures in the second heating step (main heating) were changed to 375 ° C, 450 ° C and 480 ° C.

(Example 17)

In the first heating step (preliminary heating), the heating temperature was 325 DEG C and the temperature was adjusted so that the inlet temperature was not lower than the heating temperature. The number of revolutions of the stirring in the preliminary heating was set at 50 rpm (constant).

(Example 18)

In the first heating step (preheating), the same conditions as in Example 17 were set, except that the number of revolutions of stirring was set at 100 rpm (constant).

(Example 19)

The temperature of the first segment (inlet portion) was set to 320 ° C and the temperature of the second segment (central portion) and the third segment (outlet portion) were set to 310 ° C in the first heating process (preliminary heating) Except that, the same conditions as in Example 18 were set.

(Comparative Example 1)

The degree of oxidation of the feedstock (raw material) is set at 70%, and the preliminary heating is not performed, and the main heating for plowing is performed at 450 占 폚. In this heating, a continuous (four-stage) heating furnace was used. Comparative Example 1 corresponds to a conventional method of manufacturing a podium with a melt.

(Comparative Example 2)

The same conditions as those of Comparative Example 1 were set, except that the degree of oxidation of fines was 70%.

(Comparative Example 3)

The same conditions as in Example 1 were set, except that the oxidation degree of the fines was adjusted to 60%.

(Comparative Examples 4 and 5)

The same conditions as in Example 9 were set, except that the heating temperatures in the first heating step (preliminary heating) were changed to 250 캜 and 340 캜.

(Comparative Example 6)

The same conditions as in Example 13 were set up, except that the heating temperature in the second heating step (main heating) was set at 300 캜.

In Table 1, various conditions and results were confirmed as follows.

[Oxidation degree (%) of fecal matter]

The degree of oxidation of the flakes is measured by acetic acid titration. Acetic acid titration is carried out in the following order. 80 ml of an aqueous acetic acid solution (specific gravity 1.010 / 35 占 폚) is metered with a measuring cylinder, and the measuring cylinder is adjusted to a range of 35 占 占 폚 in the heating bath. On the other hand, an aluminum cup is put on a moisture meter (MX-50 manufactured by A & D Co., Ltd.) and weighed 4 g per minute for measurement. Transfer the balance of acetic acid and aluminum cup of the measuring cylinder to a beaker and stir. Stirring is carried out until the solution in the beaker becomes transparent while the metal lead is agglomerated, while the melt is crushed so that the melt is not cored. Further, with stirring for about 2 to 3 minutes, the solution becomes transparent. When the solution becomes transparent, the supernatant is removed, and the mass of the metal lead is measured after moisture is removed by a moisture meter (measurement condition: heating at 130 DEG C for 15 minutes).

[Heating temperature of preliminary heating]

The surface temperature (first heating temperature) of the heating furnace 3 (drum 5) was measured as the heating temperature of the preliminary heating. The preliminary heating is carried out while stirring the inside of the drum 5. [ As the stirring method, a stirring method using a paddle is adopted.

[Heating temperature of main heating]

(The temperature in the drum 5 when the heating furnace is a drum type) and the surface temperature of the drum 5 are measured as the heating temperature of the main heating. Further, the atmospheric temperature in the furnace is maintained at the set temperature or lower. The drum surface temperature is controlled to be equal to or higher than the set temperature. Even in this heating, stirring is performed using a paddle stirring method.

[Podium level]

The degree of cross-linking (%) is the content (mass%) of Pb ₃ O _{4 in} the sintered product (also referred to as plowing rate). The degree of cross-linking is measured by iodine titration. The iodine titration is carried out in the following order. First, acetic acid-ammonium acetate solution and 0.1 N sodium thiosulfate solution are added to the sample to be measured and stirred to dissolve completely. Then, a starch solution is added to this sample solution, and a 0.1 N iodine solution is added dropwise. The point of time when the color of the purple color due to the iodine starch reaction is indicated as the end point is titrated with the sodium thiosulfate ion remaining in the solution. In the same manner, the Pb ₃ O ₄ content (mass%) is calculated from the amount of the iodine solution used in the titration using the following equation.

Pb ₃ O ₄ content (mass%) = [0.3428 × (b'-b) × f] / S × 100

b ': Amount of iodine solution (ml)

b: Amount of iodine solution consumed in the titration of the sample (ml)

f: Factor of iodine solution

S: Amount of sample (g)

[Processing time of pedestrianization (h)]

The processing time (h) for plowing was set to a constant (preheating: 0.5 h, main heating: 3.0 h).

[Production of podium (kg / h)]

The production amount of the podium (kg / h) was aimed at 300 to 600 kg / h as the amount of the pod that can be produced within the above-mentioned processing time (constant).

[Overall evaluation]

A comprehensive evaluation was carried out from the respective evaluation results of the panning degree and the production amount of the podium (base is the processing time). The comprehensive evaluation was evaluated based on the following evaluation criteria.

◎: Very good

○: Good

X: Bad

In the case where the plowing degree is less than 80% or the plowing production amount is less than 400 kg / h, the comprehensive evaluation is referred to as "Poor x". When the plowing degree is more than 80% Was evaluated as " good " and the overall evaluation was judged to be " very good " when the punching degree was 85% or more or the punching production was 500 kg / h or more.

Hereinafter, the relationship between manufacturing conditions and results will be described.

[Performance of prior art (target)] [

First, as shown in Table 1, in the prior art (target) in which the preliminary heating is not performed but the preliminary heating is performed directly on the frit, in the prior art (target), when the degree of oxidation of the frit is high (Comparative Example 1) The heating time of the plowing was prolonged and the production amount could not be increased. Further, in the case where the degree of oxidation was low (Comparative Example 2), the heating time of the plowing became long and the production amount could not be increased, and the plowing degree was also lowered.

On the other hand, it was confirmed that, as shown in Table 1, preheating was applied to the fritting before the fritting by performing the main heating to the frit, while the production amount was increased while maintaining the degree of pelletization.

[Relationship between Oxidation Tendency]

First, the conditions of the first heating step (preliminary heating) and the second heating step (main heating) were made constant, and the degree of oxidation of the input frit was changed. As a result, the degree of oxidation of the frit was 63% to 78% (Examples 1 to 8), it was possible to increase the production amount without lowering the degree of cross-linking. Particularly, in the conditions where the degree of oxidation of fats is about 67% to 80% (Examples 3 to 8), the degree of plowing was greatly improved. In addition, in the condition that the oxidation degree of the fines was 60% (Comparative Example 3), the degree of plowing was lowered.

[Relationship with heating temperature of preheating]

Subsequently, by changing the heating temperature in the first heating step (preheating) by changing the degree of oxidation of the frit and the conditions of the second heating step (main heating) before the first heating step (preliminary heating) In the bar, the heating temperature of the preliminary heating was 300 占 폚 to 330 占 폚 (Examples 9 to 13), the production amount could be increased without lowering the punching degree. Particularly, in the conditions where the preheating temperature is from 320 ° C to 330 ° C (Examples 11 to 13), the production amount can be greatly increased and the degree of plowing can be increased. In addition, in the case of the preheating heating temperature of 250 占 폚 (Comparative Example 4) and 340 占 폚 (Comparative Example 5), the degree of plowing was lowered and the production amount could not be increased.

[Relationship with heating temperature of main heating]

The heating temperature in the second heating temperature (main heating) was changed from 375 占 폚 to the heating temperature in the first heating step (preliminary heating) (Examples 14 to 16) at 480 占 폚, the throughput could be increased without lowering the degree of cross-linking. On the other hand, in the case where the heating temperature of this heating was 300 占 폚 (Comparative Example 6), the punching degree was lowered and the production amount could not be increased.

[Relation to presence or absence of stirring]

(Examples 17 and 18) in which the degree of oxidation of fines, the heating temperature of the preliminary heating, and the heating temperature of the main heating were kept constant and the preliminary heating was performed while stirring the fines (Examples 17 and 18) It was able to greatly increase.

In particular, that the temperature of the preheating schedule 50min ^-1 (Example 17) from the predetermined 100min ^-1 (Example 18) when raised, the platform can maintain a high degree of variation occurs even when the inputs for each other on in the continuous operation Could know.

[Relationship with inlet temperature of preliminary heating]

The heating temperature of the preliminary heating is set so that the temperature of the inlet portion 5a does not become lower than the temperature of the central portion 5b and the outlet portion 5c of the drum 5 (Examples 18 and 19) in which preheating is performed so that the temperature of the center portion 5b and the outlet portion 5c of the inlet 5 are equal to the temperature of the inlet portion 5a, , The production amount per unit time could be greatly increased.

The embodiments and examples of the present invention have been specifically described above, but the present invention is not limited to these embodiments and examples. For example, the conditions of the heating furnace employed in the first heating step and the like can be arbitrarily determined. In other words, it goes without saying that the modes described in the above-mentioned embodiments and experimental examples can be modified based on the technical idea of the present invention, unless otherwise stated.

According to the present invention, preheating is performed at a temperature not higher than the heating temperature in the main heating before the main heating for the plowing is performed, the plow having a relatively low degree of oxidation, The present invention can provide a method of manufacturing an active material for lead-acid battery which can shorten the processing time for the lead-acid battery and increase the production amount.

1: Preheating device
3: heating furnace
5: Drums
51:
52: the other end
5a: inlet portion
5b: central portion
5c: outlet portion
7:
7a:
9:
9a: outlet
11: Intake port
13: Exhaust hole
15, 17: Fan
19: partition plate
21, 23, 25: thermometer

Claims (7)

A method of manufacturing an active material for lead-acid storage batteries, comprising the steps of: heating a lead-free solder and a metal lead as main components to produce a lead edge for use as an active material for a lead-
A first heating step of heating the frit at a first heating temperature to oxidize the metal lead in the frit,
And a second heating step of heating the frit heated in the first heating step at a second heating temperature to soften the frit,
The frit before heating in the first heating step is produced by pulverizing a metal lead by a ball mill method,
Wherein the first heating temperature is lower than or equal to the second heating temperature. A method of manufacturing an active material for lead-acid storage batteries, comprising the steps of: heating a lead-free solder and a metal lead as main components to produce a lead edge for use as an active material for a lead-
A first heating step of heating the frit at a first heating temperature to oxidize the metal lead in the frit,
And a second heating step of heating the frit heated in the first heating step at a second heating temperature to soften the frit,
The frit before heating in the first heating step has an oxidation degree of 63% or more,
Wherein the first heating temperature is lower than or equal to the second heating temperature. The method of manufacturing an active material for lead-acid storage batteries according to claim 1 or 2, wherein the first heating temperature is 300 to 330 占 폚. The method of manufacturing an active material for lead-acid storage battery according to any one of claims 1 to 3, wherein the heating of the frit in the first heating step is performed while stirring the frit. The method according to any one of claims 1 to 4, wherein the first heating step is carried out using a heating furnace,
A first segment constituting an inlet portion into which the fuel is injected into the heating furnace,
A second segment continuous to the first segment and constituting a central portion of the heating furnace,
And a third segment that is continuous to the second segment and constitutes an outlet portion for discharging the frit out of the heating furnace,
Wherein the first heating temperature is set so that the heating temperature in the first segment is not lower than the heating temperature in the second segment and the heating temperature in the third segment, ≪ / RTI > The method of manufacturing an active material for lead-acid storage batteries according to any one of claims 1 to 5, wherein the oxidation degree of the frit is 67% or more. The method for producing an active material for lead-acid battery according to any one of claims 1 to 6, wherein the second heating temperature is 375 to 480 占 폚.

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