JP2010007104A - Apparatus and method for treating dross - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain powdery dross without using an impeller-breaker, which needs high energy consumption and causes dusting and noise, and without causing any operating trouble caused by non-solidified lead stuck to the surface of the dross. <P>SOLUTION: The apparatus for trating the dross is provided with: a drum-type cooling device having the drum for charging the dross stuck to the molten lead; a dross relay hopper having a vibration feeder for supplying the dross into the drum-type cooling device at the lower part; a container tilting device for carrying a container to the dross relayed hopper and charging the dross into the hopper by tilting the container; and a carrying conveyor for conveying the fine granular lead and the powdery dross exhausted from the drum-type cooling device to a dross-storing bin for storing, are provided. In the apparatus, the dross stuck to the molten lead is made in contact with the rotating drum to solidify the molten lead under non-solidifying state by a stirring-cooling, thereby obtaining the fine granular lead and the powdery dross. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a dross treatment facility and a method for adhering molten lead generated in a simultaneous lead-zinc smelting method (ISP method).

  There is an ISP method as a typical dry zinc smelting method for simultaneously recovering lead and zinc from zinc concentrate containing lead. In this ISP method, a sulfide concentrate as a raw material is sintered to obtain zinc oxide, and this zinc oxide is converted into zinc vapor by reductive dissolution, and then this zinc vapor is introduced into a lead splash capacitor. In a lead splash capacitor, zinc is absorbed into molten lead by injecting molten lead into zinc vapor and bringing them into contact with each other. Crude zinc is obtained by adjusting the temperature of the molten lead that has absorbed zinc and separating it into lead and zinc (see Patent Documents 1 and 2).

 However, some zinc vapor is oxidized before being absorbed to become powdered zinc oxide and floats as dross on the surface of the molten lead of the splash capacitor. In addition, when sintered ingots, briquettes and coke are charged as raw materials in the blast furnace, dust generated by collisions between these raw materials or drop impacts is also brought into the splash condenser, and the above-mentioned powder is used. Like the zinc oxide, it floats as dross on the surface of the molten lead.

  The molten lead that has absorbed the zinc in the splash condenser is pumped out to the cooling tank by the lead pump, cooled through the cooling tank, and the specific gravity of the molten lead is reduced by decreasing the temperature of the molten lead. Is recovered. The place where the lead pump is installed is referred to as “pump sump” as described in Patent Document 2. In this pump sump, dross flowing from the splash condenser floats along with the molten lead, and this fills the surface of the pump sump.

 This dross is scraped out by a scraper type conveyor installed on the upper surface of the pump sump, and is put into the dross processing step. An outline of a conventional dross treatment process is shown in FIG. The temperature of the dross at the time of scraping in the dross treatment process is about 500 ° C., and molten lead is attached to the surface.

 First, the scraped out dross is stored in a container. By temporarily placing such a container, the dross is cooled and solidified or condensed into a plate shape or a lump shape. On the other hand, the molten lead adhering to the surface of the dross aggregates, accumulates in the lower part of the container by its own weight, and solidifies by heat radiation from the bottom plate and the side plate of the container. Thereafter, the dross is conveyed to the dross relay hopper, and only the dross in the container is charged into the hopper.

  Thereafter, the dross is supplied to a crusher (impeller breaker) by a vibration feeder disposed at a lower portion of the dross relay hopper, and is crushed into powder by a crusher such as an impeller breaker. Next, the crushed dross is charged into a storage tank (dross stock bin) via a bucket elevator and a flow conveyor, and is subjected to a sintering process which is the next process.

In the dross treatment method described above, dross and molten lead are separated in the cooling step by temporarily placing the container, but some lead remains in a solid dross that has solidified or condensed in an unsolidified state. After the cooling process, a crushing process is provided to process the massive dross in the sintering process, but if the amount of dross generated is large, unsolidified lead adheres to the impeller and casing of the impeller breaker. Troubles such as shoot clogging and vibration are often generated. In addition, the dust generation and noise from the impeller breaker has led to the deterioration of the working environment in the dross treatment facility.
JP-A-7-70660 Japanese Unexamined Patent Publication No. 7-34148

  The object of the present invention is not to use an impeller breaker that causes high energy consumption, dust generation and noise, and does not cause any operation trouble due to unsolidified lead adhering to the surface of the dross. It is another object of the present invention to provide a dross treatment facility and a treatment method capable of obtaining powdery dross.

  The present invention relates to a dross treatment facility with molten lead generated in the ISP method.

 In particular, the present invention has a drum in which the dross to which the molten lead adheres is charged, the dross to which the molten lead adheres is solidified by stirring and discharging, and fine lead and powdery dross are discharged. A drum-type cooling device is provided.

  As means for supplying the dross with the molten lead attached to the drum type cooling device, the dross relay hopper having a vibration feeder at the bottom is provided, and the dross with the molten lead attached is retained in the dross relay hopper, It is preferable that the supply amount can be adjusted.

  The dross to which the molten lead adheres is scraped from a pump sump of a lead splash condenser facility used in the ISP method, accommodated in a container, and conveyed to the dross treatment facility. In order to supply the dross with the molten lead adhering from the container to the dross relay hopper, it is preferable to include a container tilting device having means for tilting the container.

  When the level at which the container is transported is different from the level at which the dross relay hopper is loaded, the container tilting device is a device for transporting the container to the position of the dross relay hopper. It is preferable to provide.

  The fine lead and powdery dross after processing are stored in a dross stock bottle and further processed in a sintering process which is the next process. Therefore, it is preferable to provide a transport conveyor that transports the fine-grained lead and powdered dross discharged from the drum type cooling device to the dross stock bin for storage.

The overall heat transfer coefficient of the drum-type cooling device is preferably 500 to 600 kJ / (m ² · hr · K).

  The drum-type cooling device is preferably a water-cooled device having means for supplying a refrigerant to the outer surface of the drum.

  It is preferable to provide at least one dam on the inner surface of the drum.

  It is preferable that a sieve having an opening of 5 to 10 mm is provided at the discharge port of the drum type cooling device from which the fine lead and powdery dross are discharged.

  The present invention also relates to a method for treating dross adhered to molten lead generated in the ISP method.

  In particular, the present invention has a cooling step in which the dross to which the molten lead adheres is solidified by stirring and cooling the molten lead in an unsolidified state to form fine-grained lead and powdery dross. There is.

  The method includes a drum in which the dross to which the molten lead adheres is charged according to the present invention, the dross to which the molten lead adheres is solidified by stirring and cooling, and fine lead and powdery dross A dross relay that has a drum-type cooling device for discharging the dross, and a vibration feeder for supplying the dross to which the molten lead adheres to the drum-type cooling device at a lower portion, and adjusts the supply amount of the dross to which the molten lead adheres A hopper, a container tilting device for supplying the dross with the molten lead attached thereto to the dross relay hopper, and fine granular lead and powdered dross discharged from the drum type cooling device for storing these It is preferable to use dross processing equipment provided with a transport conveyor for transporting to the dross stock bin.

In carrying out the method of the present invention, the overall heat transfer coefficient of the drum type cooling device is preferably set to 500 to 600 kJ / (m ² · hr · K).

  In the dross relay hopper, the residence time of the dross to which the molten lead is attached is preferably 20 to 40 minutes.

  It is preferable to adjust the operating conditions of the drum-type cooling device so that the temperature of the fine-grained lead and powdered dross discharged from the drum-type cooling device is 300 ° C. or lower.

  It is preferable that the time for the cooling step in the drum type cooling device and the time for accommodating the dross with the molten lead attached to the container from the pump sump of the lead splash condenser used in the ISP method are preferably matched.

  In the present invention, dross adhered to the molten lead generated by the ISP method can be recovered in a state separated into fine granular lead and powdered dross by quickly cooling with a drum type cooling device. . Therefore, the apparatus and process which crush blocky dross with an impeller breaker become unnecessary. This can also prevent troubles caused by unsolidified lead in the operation of the impeller breaker.

  Therefore, since dross is processed by a more efficient process than before, energy saving and cost reduction can be achieved. At the same time, the working environment can be greatly improved by removing the impeller breaker from the processing equipment.

1. FIG. 1 schematically shows one embodiment of a dross processing facility according to the present invention.

  The feature of the present invention is that, instead of temporarily placing a conventional container in the cooling process, a drum type cooling device is adopted, and dross with molten lead adhered is solidified by stirring and cooling, so that both dross and lead are in a lump. Instead, it is directly in the form of a fine granular or powdery form.

  In FIG. 2, the cross section of the one aspect | mode of the drum type cooling device employ | adopted as the dross processing equipment concerning this invention is shown roughly.

  The drum-type cooling device includes a cylindrical drum, a dross loading port provided on the upstream side of the drum, and a dross discharge port provided on the downstream side of the drum, and the drum is rotatable in the circumferential direction. Installed on support means.

  The drum is rotated such that the rotation speed is controllable by a driving device (not shown). Further, the lift device (not shown) can move the upstream side of the drum in the vertical direction with the downstream side of the drum as a fulcrum, and the drum can be inclined at an arbitrary angle in the axial direction.

  In the present invention, the dross is charged into the drum with molten lead adhering to the surface. The temperature of the dross at the time of charging the drum is set to a temperature exceeding 327 ° C., which is the melting point of lead, that is, 350 ° C. or higher, preferably 400 ° C. or higher. That is, after the dross is received from the pump sump, it is quickly charged into the drum type cooling device.

  The dross to which the charged molten salt is attached by the rotation of the drum is stirred and cooled by contact with the inner surface of the drum. The molten lead separates from the dross by agitation cooling and solidifies into fine particles while moving downstream as the drum tilts. On the other hand, the dross from which the molten lead is separated also solidifies into a powder form by stirring and cooling. And these fine-grained lead and powdery dross are discharged | emitted from the discharge port provided in the downstream of the drum.

  In order to prevent unsolidified lead from re-adhering to the surface of the dross, it is necessary to set the temperature of the discharged material at the time of discharge to 300 ° C. or less, considering that the melting point of lead is 327 ° C. is there. More preferably, it shall be 250 degrees C or less. From the viewpoint of preventing the adhesion of lead, this temperature is preferably lower. However, it is desirable that the temperature be 100 ° C. or higher in order to increase the size of the processing equipment and impair the economy.

  In addition, the temperature of the lead and dross at the time of discharge can be adjusted by appropriately controlling the drum configuration, operating conditions, and the like, which will be described later.

  In addition, the cooling process in the drum type cooling apparatus can employ a continuous process for sequentially supplying dross into the drum, but can also be a batch type or intermittent type process.

The overall heat transfer coefficient of the drum-type cooling device used in the present invention is preferably 500 to 600 kJ / (m ² · hr · K). This is because if the overall heat transfer coefficient is less than 500 kJ / (m ² · hr · K), the total length of the cooling device must be increased, so that it has to be a special specification and the cost increases. . On the other hand, if it exceeds 600 kJ / (m ² · hr · K), the cooling speed inside the drum becomes high, and it becomes difficult to obtain an appropriate powdery dross.

Here, the overall heat transfer coefficient of the drum type cooling device is
“Overall heat transfer coefficient (U) = Slow heat amount / (Heat transfer area × Time × Temperature difference)”
It is calculated by the formula. Note that the heat removal amount is calculated by the equation “heat removal amount = quantity × dross specific heat × temperature difference” where the dross specific heat is 0.445 KJ / hr · K.

  Basically, the overall heat transfer coefficient is determined by the material of the drum. The amount of heat removal varies depending on the drum gradient, the number of rotations of the drum, and the amount of cooling water. Therefore, a drum-type cooling device having a drum made of an appropriate material is selected, and operating conditions are appropriately controlled.

  The drum-type cooling device according to the present invention is preferably a water-cooling type in which means for cooling the outside of the drum is provided by introducing cooling water from the outside as a refrigerant. The cooling efficiency of the processing object is improved by cooling the drum with the refrigerant. Further, by adjusting the flow rate of the refrigerant, the cooling rate in the cooling device can be easily adjusted. In addition, about this cooling means, if it is a structure which can supply a refrigerant | coolant to the whole or a part of drum, since a well-known structure can be employ | adopted, detailed description is abbreviate | omitted.

  In the drum-type cooling device according to the present invention, it is preferable that at least one dam is provided on the inner surface of the drum. By providing the dam, the flow of dross inside the drum is changed, so that sufficient contact between the dross and the drum is achieved, and the dross is sufficiently agitated. As well as separating, the effect of transferring lead into fine particles and transferring dross into powder is sufficiently obtained.

  As the dam, an iron square can be used. For example, it is desirable to extend this square bar in the axial direction of the dam. Moreover, in order to perform stirring force more strongly, it is preferable to introduce 4 to 8 diagonally with respect to the drum circumference.

  In the drum type cooling device according to the present invention, there is a possibility that massive dross is generated in part due to non-uniform cooling or non-uniform stirring. In order to minimize the generation of massive dross, in addition to the installation of dams as described above, measures should be taken by appropriately selecting the rotation speed and inclination (gradient) of the drum and the cooling speed of the cooling device. Is possible.

  In addition, the time required for the cooling process (the time during which dross stays in the drum-type cooling device) can be adjusted by appropriately regulating these operating conditions in consideration of the size and configuration of the drum.

  The rotation speed, inclination angle, and cooling rate of these drums are adjusted as appropriate according to the configuration of the drum-type cooling device according to the temperature and amount of the dross with molten lead introduced into the dross treatment process. The

  Note that there is a possibility that dross may not be partially agglomerated even by such regulation of operating conditions. It is preferable to provide a sieve having an opening of 5 to 10 mm at the discharge port of the drum type cooling device so as not to insert such a blocky dross into the dross stock bin (storage tank). In addition, a well-known thing can be employ | adopted for this sieve.

  In the dross treatment facility shown in FIG. 1, the dross adhered to the molten lead produced is collected from the pump sump of the ISP lead splash condenser, and then charged into the drum-type cooling facility. As an apparatus used for the above steps, a container tilting device and a dross relay hopper with a vibration feeder are provided. Moreover, the conveyance conveyor which conveys the discharged | emitted fine granular lead and powdery dross to the dross stock bin which stores these is provided.

  At the pump site of the lead splash capacitor in the ISP method, the dross floating on the surface of the molten lead (lead bath) is scraped out by a scraper type conveyor disposed on the upper surface of the pump sump and accommodated in a container. Molten lead adheres to the surface of the dross. In addition, the temperature of the dross at the time of discharge | emission from a pump sump is about 500 degreeC.

  By adjusting the number of rotations of the scraper type conveyor, it is possible to adjust the time for housing molten lead from the conveyor into the container. It is preferable to approximate the storage time for one container and the above-described cooling process time (the time during which dross stays in the drum-type cooling device) because the work in the cooling process is simplified.

  Next, the container is transported to a predetermined receiving place in the container tilting device by a reach forklift or the like and placed at a predetermined position. Prior to putting the dross into the drum-type cooling device, the container containing the dross is placed in the container by the transport means (lift, etc.) of the container tilting device so as to be loaded into the dross relay hopper. It is raised to the floor where the dross relay hopper is received, which is higher than the floor, and tilted at the loading entrance. In the present invention, the container is not temporarily placed and is supplied to the dross relay hopper in a high temperature state when accommodated in the container.

  If the level at which the container is transported and the level at which the dross relay hopper is installed are the same, the dross may be loaded directly from the container into the dross relay hopper as in the prior art. .

  The dross relay hopper is a means for supplying dross to the drum type cooling device and is a means for adjusting the supply amount. As the dross relay hopper, an existing hopper can be adopted, and similarly, a vibration feeder is provided in the lower part.

  The dross loaded in the dross relay hopper is put into a drum-type cooling device in a state where the molten lead remains attached by an extraction vibration feeder attached to the lower portion of the hopper. The supply amount of the dross is adjusted by regulating the frequency and inclination of the vibration feeder, the distance between the lower outlet of the dross relay hopper and the vibration feeder, and the like.

  In addition, it is not desirable that molten lead and dross are separated in the dross relay hopper and the molten lead adheres to the inner surface of the dross relay hopper and solidifies in the dross relay hopper. It is desirable that the time is 20 to 40 minutes. As described above, the temperature of the dross supplied from the dross relay hopper to the cooling device is about 400 to 500 ° C., and lead is maintained in a molten state.

  Fine lead and powdery dross obtained by the cooling device are transported and stored in a dross stock bin as a storage tank by a flow conveyor or the like.

  The dross stored in the dross stock bin is transported to the sintering process which is the next process by a belt conveyor which is a general transport device.

  Thus, in the dross processing equipment of the present invention, since the dross in the form of powder can be obtained sufficiently and efficiently by the drum-type cooling device, a crusher such as an impeller breaker that has been conventionally used is installed. There is no need. Therefore, in the treatment facility of the present invention, factors such as dust generation and noise are removed from the facility. As a result, the working environment of the dross processing facility is greatly improved. Further, by removing the crusher, it is possible to achieve energy saving and cost reduction in terms of power.

Example 1
In the present example, the dross treatment facility according to the present invention was actually operated, and it was examined whether or not a desired powdery dross could be recovered.

  The drum-type cooling device installed in the processing facility used in this example employs a drum that enables a dross processing amount of 30 t / 24 hr, and the inclination angle of the drum is 1/100 to 1 with respect to the horizontal plane. Adjustment with a liner and jack was made possible so that / 5. Further, the drive device can be controlled so that the rotation speed of the drum is 2.5 to 15 rpm. With these controls, the dross residence time can be adjusted between 1 and 30 minutes.

  The inner diameter of the iron drum of the drum-type cooling device is 489 mm, the total length of the drum is 3200 mm, and the length of the cooling unit is 2000 mm. The thickness of the drum is 9.5 mm. Inside the drum, iron square bars of 20 × 20 × 1400 mm were attached as dams that change the flow of dross at six locations that are equal in the circumferential direction so that the square bars extend in the axial direction of the drum. With respect to the cooling water, nozzle holes with a diameter of 4.5 mm were drilled at intervals of 70 mm in the lower part of the cooling water bottle disposed at the upper part of the drum so that the water film was uniformly stretched over the entire length of the cooling part. In addition, a 5 mm square sieve was provided at the lower outlet of the cooling device.

  Next, the operation of the dross processing facility will be described. First, 1.5t of dross was accommodated in a container over 20 minutes using a scraper type conveyor of a pump sump.

  After dross accumulates in the container, the container is transported to a receiving place below the container tilting device by a reach forklift, the container is placed at a predetermined position, the container is lifted by the container tilting device, and the upper part of the dross relay hopper The dross stored in the container was fully loaded into the dross relay hopper.

  The vibration feeder is adjusted so that the amount of dross processing is 24 t / 24 h, the rotation speed of the drum type cooling device is adjusted to 11 rpm, and the inclination angle is adjusted to 1/100 °, respectively. Through this, copper dross was continuously charged into the apparatus. The cooling water supplied to the drum-type cooling device was supplied to the outside of the drum at a temperature of 24 ° C. at a rate of 2.4 t / h.

  The temperature of the dross supplied to the drum type cooling device was 550 ° C., and the temperature of the discharged powdered dross was 174 ° C. Moreover, the residence time of the dross in the drum type cooling device was 4 minutes.

From the above results, the overall heat transfer coefficient of the drum type cooling device was calculated. As a result, the overall heat transfer coefficient was about 530 kJ / (m ² · hr · K).

  An appropriate powdery dross was able to be obtained through the operation process of the above dross processing equipment. Moreover, the lead was recovered in a fine granular form, and no adhesion to the surface of the dross was observed.

(Example 2)
Other than adjusting the vibratory feeder so that the amount of dross treated is 20 t / 24 hr, the temperature of the cooling water supplied to the cooling device is 36 ° C., and supplied to the outside of the drum at a rate of 4.0 t / hr In the same manner as in Example 1, an appropriate powdery dross could be obtained.

  The temperature of the dross supplied to the drum type cooling device was 550 ° C., and the temperature of the discharged powdered dross was 108 ° C. Moreover, the residence time of the dross in the drum type cooling device was 4 minutes.

  Moreover, in any of Example 1 and 2, the quantity of the blocky dross seen on the sieve attached to the exit lower part of a cooling device is a grade which can be disregarded in view of the recovery rate of powdery dross. Met.

FIG. 1 is a schematic diagram showing an embodiment of a dross processing facility according to the present invention. FIG. 2 shows a drum-type cooling device in a cross-sectional view. FIG. 3 is a schematic diagram showing a conventional dross processing facility.

Claims (15)

  A dross treatment facility for molten lead adhering to the lead and zinc simultaneous smelting process, which has a drum charged with the dross adhering to the molten lead, and stirring and cooling the dross adhering to the molten lead A dross treatment facility comprising a drum type cooling device that solidifies and discharges fine granular lead and powdery dross.   The apparatus further comprises: a vibration feeder for supplying the dross adhered with the molten lead to the drum type cooling device at a lower portion, and further comprising a dross relay hopper for adjusting a supply amount of the dross adhered with the molten lead. The dross treatment facility described.   The container tilting device according to claim 2, further comprising means for tilting a container that accommodates the dross to which the molten lead adheres in order to supply the dross to which the molten lead adheres to the dross relay hopper. Dross processing equipment.   The dross processing equipment according to claim 3 with which said container inclination point device is provided with the device which conveys said container to the position of the loading entrance of said dross relay hopper.   5. The apparatus according to claim 1, further comprising a transport conveyor that transports the fine-grained lead and powdered dross discharged from the drum-type cooling device to a dross stock bin for storing them. Dross processing equipment. The dross processing equipment according to any one of claims 1 to 5, wherein the overall heat transfer coefficient of the drum-type cooling device is 500 to 600 kJ / (m ² · hr · K).   The dross treatment maintenance according to any one of claims 1 to 6, wherein the drum-type cooling device is a water-cooled device having means for supplying a refrigerant to the outer surface of the drum.   The dross processing equipment according to any one of claims 1 to 7, comprising at least one dam on an inner surface of the drum.   The dross according to any one of claims 1 to 8, wherein a sieve having an opening of 5 to 10 mm is provided at an outlet of the drum type cooling device from which the fine lead and powdery dross are discharged. Processing equipment.   A dross treatment method for molten lead adhering to lead / zinc simultaneous smelting process, wherein the molten lead adhering dross is solidified by stirring and cooling in a state where the molten lead is not solidified. The dross processing method which has a cooling process made into granular lead and powdery dross.   A drum type cooling device having a drum charged with the dross to which the molten lead is attached, stirring and cooling the dross to which the molten lead is adhered, and discharging fine lead and powdery dross; A vibration feeder for supplying the dross with the molten lead attached to the drum type cooling device at a lower part, a dross relay hopper for adjusting a supply amount of the dross with the molten lead attached, and the molten lead attached A container tilting device for supplying dross to the dross relay hopper, a transport conveyor for transporting fine lead and powdered dross discharged from the drum type cooling device to a dross stock bin for storing them The dross processing method of Claim 10 using the dross processing equipment provided with this. The dross processing method according to claim 11, wherein the overall heat transfer coefficient of the drum-type cooling device is 500 to 600 kJ / (m ² · hr · K).   The dross processing method of Claim 11 or 12 which makes the residence time of the dross to which the molten lead adheres in the dross relay hopper be 20 to 40 minutes.   The operating condition of the drum type cooling device is adjusted such that the temperature of the fine lead and powdered dross discharged from the drum type cooling device is 300 ° C or lower. The dross processing method according to one item.   The time of the said cooling process in the said drum-type cooling device, and the accommodation time of the dross which the said molten lead adhered to the said container from the lead-zinc simultaneous smelting process are made to correspond. The dross processing method as described in 2 ..

Images