JP2007132654A - Screw conveyer type purifying device, and purifying method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain only pure material by eliminating only impurities from pure material containing the impurities (mixture) by the principle of fractional crystallization or recrystallization. <P>SOLUTION: The screw conveyer type purifying device includes a screw conveyer 200 having a hollow cross section, formed so as to extend in a longitudinal direction, for moving the mixture inside, and a reaction adjusting part for separating the mixture into the pure material and impurities and moving them by controlling an internal temperature of the screw conveyer so as to repeat dissolution and solidification operation of the mixture. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a screw conveyor type purification apparatus and a purification method using the same, and more particularly, a pure product containing impurities (hereinafter referred to as “mixture”) based on the principle of fractional crystallization or recrystallization. The present invention relates to a screw conveyor type refining apparatus that removes only impurities from the above to obtain only a pure product, and a refining method using the same.

  As conventional methods for removing lead which is an impurity contained in a tin alloy which is a mixture, (1) chlorination method described on page 232 of Non-Patent Document 1, and (2) described on page 239 of the same document Vacuum evaporation method and (3) crystal crystallization method disclosed in Patent Document 1.

However, the chlorination method of (1) uses expensive SnCl ₂ -2H ₂ O or dangerous chlorine (Cl ₂ ) gas, and therefore the operation is dangerous, and the processing cost is very high. The processing of dross _{(SnCl 2} -PbCl 2) induces pollution not only very complicated, the SnCl ₂ -2H ₂ O manufacturing and dross _{(SnCl 2} -PbCl 2) processing of Poisonous and Deleterious Substances There was a problem that the work was dangerous to handle, requiring permission to handle poisonous and deleterious substances and a pollution prevention facility. In particular, since the metal content ratio of tin (Sn) and lead (Pb) in the dross is 93.46% (Sn): 6.54% (Pb), the removal rate of lead (Pb) is low. There were problems such as.

  The vacuum evaporation method (2) is a method of distilling impurities such as lead at a working temperature of 1,250 ° C. and a vacuum degree of 0.01 mmHg using a vacuum evaporation facility that processes 16 tons per day. In addition, an expensive high-frequency induction furnace and a high vacuum facility are required, and the power consumption per ton of the processed metal is 600 KwH / ton, and there is a problem that the power consumption is large.

  In addition, the invention disclosed in Patent Document 1 (Chinese Patent Publication No. 85 1 07536 A) of (3) above is composed of an inner tank and an outer tank, and a U-shaped steel tank having an open top. And a rotating shaft that is rotatably installed inside the U-shaped steel tank, and in which three spiral pieces are welded at an angle of 86.5 °, and project in three directions, and the U-shape. It consists of a heating electric heater installed at the bottom of a steel tank.

However, this is composed of a U-shaped steel tank with an open top and a rotating shaft provided with a spiral piece, and is equipped with a temperature control device and a cooling device for accurate temperature control. In addition, there is a problem that the removal rate of lead (Pb) is low because a recrystallization step that repeats melting and solidification (crystallization) cannot be performed.
Chinese Patent Publication No. 85 1 07356 A Extractive metallurgy of tin second edition (1982)

  The present invention has been made in order to solve such problems of the prior art, and is a screw conveyor type purification apparatus capable of obtaining impurities by removing impurities from a mixture and a purification method using the same. The purpose is to provide.

  Another object of the present invention is a screw conveyor type refining apparatus capable of removing lead (Pb) in tin metal or a tin alloy to 0.05% or less which is A (ASTM B 339-72 Classification of pig tin) standard and the like. It is to provide a purification method using

  In order to achieve such an object, the present invention has a screw conveyor that has a hollow cross section and extends in the longitudinal direction, and moves the mixture inside in both directions, and the melting and solidification operations of the mixture. There is provided a screw conveyor type purification apparatus including a reaction control unit that controls the internal temperature of a screw conveyor to be repeated and separates and moves the mixture into a pure product and impurities.

  In the present specification, pure tin metal, tin alloy and tin eutectic alloy are referred to as “pure tin alloy”, and Sn—Pb eutectic metal enriched in lead as impurity is referred to as “impurity tin alloy”. It is called “alloy”.

  That is, the melting point of pure tin alloy (Sn: 231.9 ° C., Sn-Ag: 221 ° C., Sn—Ag—Cu: 216 ° C.) and the melting point of impurity tin alloy in which lead is concentrated (Sn—Pb: 183) The refinement | purification apparatus which raises purity by repeatedly crystallizing a pure tin alloy (Sn, Sn-Ag, Sn-Ag-Cu) using the difference with (degreeC) is provided.

  Here, the tin alloy includes a Sn—Pb system, a Sn—Ag system, and a Sn—Ag—Cu system.

  Hereinafter, the process of refine | purifying a tin alloy using the refiner | purifier of this invention is demonstrated.

  (1) Pure tin metal (Sn 100%) and tin eutectic alloy have a single temperature melting point. That is, the melting point of pure tin metal is 231.9 ° C., the melting point of the Sn—Pb eutectic alloy is 183 ° C., and the component ratios are 61.9% for Sn and 38.1% for Pb. However, the melting point of the Sn—Pb alloy is not a single temperature, but has a temperature range of 183 to 231.9 ° C. depending on the ratio of the Sn / Pb alloy.

  (2) Normally, the lead (Pb) content in crude tin metal is less than 0.5%. Therefore, in order to reduce (remove) the content of lead (Pb), which is an impurity in the crude tin, an Sn—Pb eutectic alloy (Sn 61.9%, Pb 38.1%) having a melting point of 183 ° C. is formed. When the lead (Pb) in the crude tin is removed, the tin metal containing only a small amount of lead (Pb) and having a melting point of 231.9 ° C. is partially solidified and partially crystallized. Through the recrystallization process of repeating such a process, the refined tin metal can be removed at low cost without requiring a pollution prevention facility. That is, lead (Pb) which is an impurity is separated in the Sn—Pb eutectic (melting point: 183 ° C.) state.

  (3) Lead (Pb), which is an impurity, is contained in the Sn—Pb eutectic alloy and removed. The theoretical maximum content of lead (Pb) is 38.1%, but it can be concentrated to about 32-34% in actual work.

  (4) The most important point in the removal of lead (Pb) which is an impurity in tin and tin alloy in the partial crystallization method is that temperature control is accurately performed in order to increase the purity by repeating the recrystallization process. It is. For example, in the case of crude tin metal, an arbitrary temperature interval (for example, a temperature range of 230 to 231.9 ° C.) must be accurately controlled within a temperature range of 183 to 231.9 ° C.

  In the same manner, the lead (Pb) of the Sn—Ag alloy can be removed by the following principle using the screw conveyor type purification apparatus according to the present invention.

  (A) Pure tin eutectic alloy has a single temperature melting point. That is, the melting point of a pure Sn—Ag eutectic alloy (Sn 96.5%, Ag 3.5%) is 221 ° C., the melting point of the Sn—Pb eutectic alloy is 183 ° C., and the component ratio is 61 for Sn. 0.9% and Pb 38.1%. However, the melting point of the Sn—Pb alloy is not a single temperature, but has a temperature range of 183 to 231.9 ° C. depending on the ratio of the Sn / Pb alloy.

  (B) Usually, the lead (Pb) content in the Sn—Ag alloy (Sn 96.5%, Ag 3.5%) is less than 1%. As described above, when lead (Pb) which is an impurity in the Sn—Ag alloy system is used to form a Sn—Pb eutectic alloy (Sn 61.9%, Pb 38.1%) having a melting point of 183 ° C. The Sn—Ag eutectic alloy (Sn 96.5%, Ag 3.5%) having a melting point of 221 ° C. is partially solidified and partially crystallized. Sn-Ag eutectic alloy (Sn 96.5%, Ag 3.5%) refined by recrystallization process is produced, so lead (Pb) can be removed at low cost without the need for pollution prevention facilities it can. That is, lead (Pb) which is an impurity is separated in the Sn—Pb eutectic (melting point: 183 ° C.) state.

  (C) Lead (Pb) as an impurity is 38.1% of the Sn—Pb eutectic alloy component, but lead (Pb) can be concentrated to about 32 to 34% in a normal operation.

  (D) As described in (4) above, the most important point in the removal of lead (Pb), which is an impurity in tin and tin alloy, in the partial crystallization method using the purification apparatus of the present invention is The temperature can be accurately controlled within the temperature range of 221 ° C.

  Based on such a theory, the tin alloys that can be removed by eutecticizing the contained lead (Pb) are Sn—Pb, Sn—Ag, Sn—Ag—Cu, and the like. The composition and purification work conditions are shown in Table 1 below, and more detailed work conditions are shown in Tables 2 to 5 below.

  That is, using the theory and method described above, not only tin and tin alloys, but also antimony (Sb) metal in lead-antimony alloys (Pb-Sb alloys) as shown in Table 5 and Example 6 below. It can also be removed.

Summary table of Pb removal work in crude tin

  Summary table of Pb removal work in Sn-Ag alloy

  Summary table of Pb removal work in Sn-Ag-Cu alloy

  Summary table of Pb removal work in Pb-Sb alloy

  According to another embodiment of the present invention, melting the crude tin or tin alloy with a kettle and maintaining it at about 250 ° C; preheating the screw conveyor to 250-280 ° C with a heater; Injecting the molten tin or tin alloy dissolved in the kettle into the screw conveyor through the preheated screw conveyor charging section, setting and controlling the working temperature of the screw conveyor, and controlling the helical screw of the screw conveyor. A method of refining a tin alloy, comprising the steps of jetting water from a water jet part while gradually rotating, partially solidifying the metal inside the screw conveyor, and transferring the solidified metal to the upper part of the screw conveyor Is provided.

  In the present invention, impurities can be removed from a mixture to obtain a pure product having a high purity. In particular, a crude tin metal containing lead (Pb) is used, and a lead (Pb) content is ASTM Grade A (ASTM B 339). -72 Classification of pig tin) Not only can it be refined to 0.05% or less, but it also removes lead (Pb) from waste lead-free solder, which is a tin alloy, to reduce waste resources. There is an effect that it can be recycled.

  On the other hand, Sn-Pb solder has been used as a bonding material in the electronic industry. However, since lead (Pb) is an environmental pollutant, it is subject to regulation. Therefore, lead-free solder, which is an environmentally friendly product, is developed or imported. Therefore, the present invention can effectively produce a lead-free solder material which is such an environment-friendly product, and has the effect of reducing pollution and substituting imports.

  In addition, according to the current Waste Electrical and Electronic Equipment Directive (WEEEE) and the Restriction on Hazardous Substances [RoHS] Directive Free Solder In this case, the lead (Pb) content is regulated to 1000 PPM (0.1%) or less. However, if the soldering operation is continued for a long time, the concentration of lead (Pb) and copper (Cu) in the lead-free solder increases and the operation cannot be continued. Therefore, the solder must be replaced. Waste solder is generated inside. By removing lead (Pb), which is an impurity, from such waste solder by the refining apparatus according to the present invention, not only can the waste resources (solder) be recycled, but also if the waste solder contains silver, the solder Recycling can save costs.

  In this specification, the screw conveyor type refining apparatus according to an embodiment of the present invention and a refining method using the refining process are attached, particularly focusing on a refining process for removing lead (Pb) as an impurity from a mixture of tin or tin alloy. This will be described with reference to the drawings.

  As shown in FIGS. 1-4, the screw conveyor type | mold refiner | purifier by this invention contains the screw conveyor 200 and the reaction control part.

  The screw conveyor 200 is installed inclined with respect to the base 100. The base 100 can be a truss-like frame.

  As shown in FIGS. 2 and 3, the screw conveyor 200 is coupled to the upper half hollow cylindrical body 204 having a semicircular cross section and the coupling portion 202 of the upper half hollow cylindrical body 204 so as to face each other. A hollow cylinder composed of a lower half hollow cylinder 205 having a circular cross section is included. A cylindrical heat insulating material 201 is inserted between the upper half hollow cylindrical body 204 and the lower half hollow cylindrical body 205, and a spiral screw 210 can be rotated inside the hollow cylindrical bodies 204 and 205 by a drive unit. Installed. Here, the cylindrical heat insulating material 201 prevents the loss of the melting heat of the tin metal in the screw conveyor 200.

  The helical screw 210 is inserted into the hollow cylindrical bodies 204 and 205 and is connected to a drive unit, for example, the drive motor 500 via the sprocket 610 and the chain 611 of the speed reducer 600. The helical screw 210 is rotated by the drive of the drive motor 500, and pushes up and moves the crystalline metal solidified by the blade 211 formed spirally on the outer periphery thereof. Here, a predetermined gap is formed between the hollow cylindrical bodies 204 and 205 and the blade 211 in order to flow the impurity metal in the molten state to the impurity discharge port 240.

  Here, in the upper half hollow cylindrical body 204, a charging portion 220 for injecting a crude metal to be purified from a separate kettle 250 is formed in communication, and the bottom surface of the lower half hollow cylindrical body 205 has lead ( An impurity discharge port 240 is formed for discharging the metal dissolved in the eutectic state of the Sn—Pb alloy enriched in Pb). In addition, a pure material discharge port 230 (product discharge port) through which purified tin is discharged is formed in communication with an upper portion corresponding to the impurity discharge port 240 of the lower half hollow cylindrical body 205. That is, the pure product outlet 230 is disposed at a position higher than the impurity outlet 240 from the floor on which the base 100 is placed. Here, when the crude tin (Sn) is purified, a valve 241 is attached to the impurity outlet 240 so that the flow of the impurity metal enriched in lead (Pb) can be adjusted.

  As shown in FIGS. 5 and 6, the reaction control unit includes a heating unit 340 that heats the screw conveyor 200, a cooling unit 440 that cools the screw conveyor 200, and temperatures that control the operation of the heating unit 340 and the cooling unit 440. And a control unit. Here, the temperature control unit includes a heating control unit 300 for controlling the heating unit 340 and a cooling control unit 400 for controlling the cooling unit 440.

  The heating unit 340 may be a heater attached to the lower half hollow cylindrical body 205 of the screw conveyor 200. As shown in FIG. 4, a plurality of heaters 340 (preferably 18 to 21) are mounted in close contact with the lower half hollow cylindrical body 205 of the screw conveyor 200, and a power source is connected to a main body formed of a copper casting. A terminal 342 is connected and heated by supplying power. In addition, a heater heat insulating portion 341 having a semicircular cross section is attached to the bottom surface of the heater 340 to prevent heat loss of the heater 340 and to keep the temperature of the lower half hollow cylindrical body 205 constant. maintain.

  In addition, in order to accurately control the degree of heating, a heating temperature sensor or thermocouple 331 is attached to the heater 340, and the heater 340 sets an appropriate temperature range by the temperature controller 330 of the heating controller 300. It is controlled so that it can be maintained.

  As shown in FIGS. 2 and 5, a voltage regulator is provided between a plurality of (18 to 21) heaters 340 and thermocouples 331 inserted in any two of the heaters and the heating control unit 300. 320, the temperature controller 330, and the instrument panel 310 are each electrically connected. Accordingly, the voltage adjuster 320 adjusts the level of the voltage applied to the plurality of heaters 340, and the temperature adjuster 330 adjusts the temperature of the heater 340 using the thermocouple 331. The instrument panel 310 visually displays the output voltage, current, and operation Kw of the voltage regulator 320 to enable overall work management.

  As shown in FIGS. 1 and 6, the cooling unit 440 is installed in the upper half hollow cylindrical body 204 of the screw conveyor 200 at a predetermined distance, sprays water, and reciprocates along a predetermined section along the screw conveyor 200. It may be a water injection portion formed so as to be movable.

  The water injection unit 440 is a combination of two solenoid valves 430 coupled to one water injector 441 and is fixedly installed on the injection table 450. The water injection unit 440 is provided above and below the loading unit 220 of the screw conveyor 200, respectively. Installed. The water injection unit 440 is installed at a predetermined distance above the screw conveyor 200 so that water can be injected while reciprocating at a predetermined distance 451 (about 35 cm) in the longitudinal direction of the screw conveyor 200.

  Further, the solenoid valve 430 is connected via a rubber hose 433 to a water pipe 432 installed in the upper part of the work place and a compressed air pipe 431 to which compressed air is supplied from a separate air compressor.

  The water injector 441, the solenoid valve 430, and the magnet switch 420 are connected to the output side of the temperature controllers 410 to 415 (the same number as the thermocouple 460) formed in the cooling control unit 400, respectively. Six cooling temperature sensors or thermocouples 460 for measuring the temperature of tin metal in the screw conveyor 200 are connected to the input sides of 410 to 415, respectively. These thermocouples 460 are sandwiched along the longitudinal direction of the cylindrical heat insulating material 201 in order to measure the temperature of the tin metal inside the screw conveyor 200.

  The temperature information of the thermocouple 460 is transmitted to the cooling control unit 400, the water injection amount of the water injection unit 440 is automatically adjusted, and the temperature inside the screw conveyor 200 is accurately maintained within the refining work control range.

  Accordingly, when an operator sets and inputs a water injection control temperature range to each of the temperature controllers 410 to 415 of the cooling control unit 400, the solenoid valve 430 is opened and closed by each of the temperature controllers 410 to 415, and the water injection unit The 440 water jet is automatically activated. Thereby, the melting temperature of the crude tin (Sn) in the screw conveyor 200 is controlled, and the recrystallization and impurity removal operations are performed as described above.

Purification method of the present invention Hereinafter, a method of refining crude tin (Sn) metal using the screw conveyor type purification apparatus according to the present invention configured as described above will be described.

  As shown in FIG. 7, the crude tin metal is dissolved in a separate kettle 250 and maintained at 250 ° C.

  Thereafter, the screw conveyor 200 is preheated to 250 to 280 ° C. by the heater 340 of the screw conveyor 200. Then, the molten metal of the kettle 250 is pumped with a stainless steel container or the like, poured into the charging section 220 and filled into the screw conveyor 200, and then the molten state of the metal is confirmed.

  The temperatures of the temperature controllers 410 to 415 of the cooling controller 400 (FIG. 6) are set to 232 ° C. at the beginning of operation. The water injection unit 440 is operated and water is injected (cooled) while the drive motor 500 connected to the screw conveyor 200 is operated and the spiral screw 210 is gradually rotated. In addition, the working temperature is set in each of the temperature controllers 410 to 415 of the cooling control unit 400.

  For example, in the case of tin metal, each temperature gradient is determined based on 232 ° C. for the uppermost temperature controller 410 and 185 ° C. for the lowermost temperature controller 415, and gradually lowered by 1 ° C. Maintain the temperature control range of operation and continue work. Here, the reference of the control temperature can be calculated by the following formula 1 obtained by experiment.

Tx ° C. = 81.5 ^(logx−1) +150.4 (1)

  Here, the tin content in the alloy is applied in the range of 61.9 to 100%.

  In the above formula 1, x is the tin content%, and when tin is 100%, 90%, 61.9%, it is calculated as follows.

T ₁₀₀ ° C = 81.5 ^{(log 100-1)} + 150.4 = 231.9 ° C.
T ₉₀ ° C = 81.5 ^{(log 90-1)} + 150.4 = 81.5 ^(1.95424-1) + 150.4 = 217.13 ° C.
T _61.9 ° C. = 81.5 ^{(log 61.9-1)} + 150.4 = 81.5 ^0.779169 + 150.4 = 183 ° C.

  In this way, the temperature adjustment range necessary for the work can be calculated using Equation 1 above.

  Next, water is injected by the water injection unit 440 to partially solidify (partially crystallize) the metal inside the screw conveyor 200. When the spiral screw 210 is gradually rotated, the solidified metal (crystal) is transferred little by little to the upper part of the screw conveyor 200.

  The heater 340 is operated by setting or operation of the heating control unit 300 to melt the solidified metal (crystal) along the liquidus shown in the Sn—Pb alloy state diagram of FIG.

  Further, water is sprayed onto the surface of the upper half hollow cylindrical body 204 of the screw conveyor 200 by the water spraying section 440 to solidify (recrystallize) the metal. In this process, when the metal solidified upon cooling is a pure metal or alloy, a eutectic alloy is formed.

  As described above, the refining operation is performed through a recrystallization process in which metal solidification and dissolution operations are repeated infinitely.

  In normal operation, the refined product is discharged from the pure product outlet 230 at the upper part of the screw conveyor 200, and the metal enriched with impurities passes through the valve 241 of the impurity outlet 240 at the lower part of the screw conveyor 200. By adjusting, about 1/8 to 1/15 of the product is discharged. As shown in each example, the discharge amount of the impurity metal is calculated by the material balance at the time of work.

  The calculated values of the amount of impurity metal are shown in the following examples and the impurity removal process diagram of FIG.

  When the Pb content in the impurity metal is around 10%, the product recovery rate is increased by circulating and repeatedly treating as shown in the impurity removal process diagram of FIG.

  When the work is finished, the operation of the water injection unit 440 and the spiral screw 210 is stopped, and only the heater 340 is operated to completely dissolve the metal remaining in the screw conveyor 200, and then the impurities are discharged. The valve 241 at the outlet 240 is opened to receive the metal into the ladle 260, and the heater 340 is turned off to complete the operation.

  The refining operation is a so-called continuous operation process in which raw material charging and product production are continuously performed. In addition, as shown in FIGS. 1, 3, 6, 7, and 8, all six thermocouples 460 sandwiched between the screw conveyor heat insulating materials 201 during operation are the temperatures of the cooling control unit 400 of FIG. The regulators 410 to 415 automatically adjust the temperature like the numerical values in Tables 2 to 5 set in advance according to the processing characteristics.

  In order to remove lead (Pb) in crude tin, the present inventor processed several hundred tons with the above-described screw conveyor type refining apparatus according to the present invention and a refining method using the same. The processing capacity is about 5 tons and the power consumption averages 91.6 KWH per ton of processed metal. Hereinafter, a part of the actual operation is shown in the examples.

Example 1
Using the screw conveyor type refining apparatus according to the present invention, the content of lead (Pb), which is an impurity in the crude tin metal (Sn), is reduced to 0.05% or less that is ASTM Grade A standard by the above-described refining method. The purification operation was performed by changing the control temperature range of actual operation in the working conditions for removal (Table 2 above) to 230 to 232 ° C. The results are as follows.

  The feed is a crude tin metal, and a crude tin metal having a lead (Pb) content of 0.055% is injected into the charging section 220 of the refiner in a molten state at 250 ° C. Purification work was performed under working conditions. Here, the reason for changing the control temperature range of the actual operation in Table 2 from 185 to 232 ° C. to 230 to 232 ° C. is that the lead (Pb) content of the crude tin metal to be refined is too low, and the control temperature This is because when the refining operation is performed at a temperature range of 185 to 232 ° C., the semi-molten metal inside the screw conveyor 200 is solidified and the refining operation is impossible.

  Thereby, the lead (Pb) content in the refined tin metal (Sn) discharged from the pure material outlet 230 of the refiner is 0.017%, which is lower than 0.05% which is the ASTM Grade A standard. Moreover, the lead (Pb) content in the impurity alloy (Sn—Pb alloy) discharged from the impurity discharge port 240 of the refiner was 1.19%. The impurity alloy is circulated as shown in the impurity removal process diagram of FIG.

  This is shown in the table below.

Example 2
The results of the purification work of Example 2 are shown in the table as follows.

Example 3
The results of the purification work of Example 3 are shown in the table as follows.

Example 4
The results of the purification work of Example 4 are shown in the table as follows.

Example 5
The results of the purification operation of Example 5 are shown in the table as follows.

Example 6
The operation of Example 6 is an operation for removing antimony (Sb) in the hard lead (Pb—Sb alloy).

  The preferred embodiments of the present invention have been described above by way of example. However, the scope of the present invention is not limited to such specific embodiments, and appropriate within the scope of the claims. Can be changed.

It is a figure which shows the structure of the screw conveyor type | mold refiner | purifier by one embodiment of this invention. It is the II-II sectional view taken on the line of FIG. It is a disassembled perspective view of the screw conveyor of FIG. It is a perspective view of the heater of FIG. It is the schematic which shows the structure of the control part which controls the heater of FIG. It is an expanded sectional view which shows the electrical connection of the water injection part of FIG. It is a figure for demonstrating the impurity refinement | purification method of a tin alloy. It is process drawing which shows the impurity removal process using the apparatus shown in FIG. It is a phase diagram of a Sn-Pb alloy. It is a phase diagram of a Sn-Ag alloy. It is a phase diagram of a Sn-Ag-Cu alloy. It is a phase diagram of a Sn-Ag-Cu alloy. It is a phase diagram of a Pb-Sb alloy.

Explanation of symbols

100 base 200 screw conveyor 300 heating control unit 400 cooling control unit 500 drive motor 600 decelerator

Claims (17)

A screw conveyor that has a hollow cross-section and is formed to extend in the longitudinal direction and moves the mixture inside;
A reaction controller for controlling the internal temperature of the screw conveyor so as to repeat the melting and solidification operations of the mixture, and separating and moving the mixture into pure and impurities;
A screw conveyor type refining device.   The screw conveyor type refining device according to claim 1, wherein the mixture contains Sn-Pb, Sn-Ag, and Sn-Ag-Cu tin alloys. The screw conveyor is
A hollow cylinder into which the mixture is charged;
A helical screw rotatably mounted inside the hollow cylindrical body;
A drive unit connected to the helical screw to rotate the helical screw;
The screw conveyor type | mold refinement | purification apparatus of Claim 1 characterized by the above-mentioned. The hollow cylindrical body is
An upper half hollow cylinder and a lower half hollow cylinder having semicircular cross-sections joined together;
A cylindrical heat insulating material disposed between the upper half hollow cylindrical body and the lower half hollow cylindrical body;
The screw conveyor type | mold refinement | purification apparatus of Claim 3 characterized by the above-mentioned. The hollow cylindrical body is
A charging section for charging the mixture to be purified;
An impurity outlet formed such that the impurities are melted and discharged;
A pure product outlet formed such that the pure product is solidified and discharged;
The screw conveyor type | mold refinement | purification apparatus of Claim 3 characterized by the above-mentioned. Further including a base,
The hollow cylindrical body is positioned with respect to the base such that the end on the side where the pure material discharge port is formed is positioned higher than the end on the side where the impurity discharge port is formed. The screw conveyor type refining device according to claim 5, wherein the refining device is mounted with an inclination. The drive unit is
A drive motor;
A speed reducer coupled to the drive motor;
A sprocket and a chain connecting the speed reducer and the helical screw;
The screw conveyor type | mold refinement | purification apparatus of Claim 3 characterized by the above-mentioned. The reaction controller is
A cooling part formed on one side of the screw conveyor to cool the mixture;
A heating unit formed on the other side of the screw conveyor to heat the mixture;
A temperature control unit that senses the internal temperature of the screw conveyor and controls the operation of the cooling unit and the heating unit;
The screw conveyor type | mold refinement | purification apparatus of Claim 1 characterized by the above-mentioned.   The cooling unit is a water injection unit that is arranged separately from the screw conveyor and injects water, and the heating unit is a heater that is attached to the screw conveyor. The screw conveyor type | mold refining apparatus as described in 1 ..   The screw conveyor type refining device according to claim 9, wherein the water injection unit is installed so as to be able to reciprocate a predetermined distance in the longitudinal direction of the screw conveyor.   The screw conveyor type refining device according to claim 9, further comprising a heater heat insulating part that is mounted on the screw conveyor so as to cover the heater and prevents heat loss of the heater. The temperature controller is
A cooling control unit for controlling the operation of the cooling unit;
A heating control unit for controlling the operation of the heating unit;
The screw conveyor type | mold refinement | purification apparatus of Claim 8 characterized by the above-mentioned. A cooling temperature sensor that extends into the screw conveyor and is electrically connected to the cooling controller, and measures the temperature of the mixture;
A heating temperature sensor mounted on the heating unit and electrically connected to the heating control unit for measuring the temperature of the heating unit;
The screw conveyor type refining device according to claim 12, further comprising: Dissolving the crude tin or tin alloy in a kettle and maintaining at about 250 ° C .;
Preheating the screw conveyor to 250-280 ° C. with a heater;
Injecting the melted crude tin or tin alloy in the kettle into the screw conveyor through the preheated screw conveyor charging section;
The working temperature of the screw conveyor is set and controlled, water is jetted from a water jetting part while gradually rotating the helical screw of the screw conveyor, the metal inside the screw conveyor is partially solidified, and the solidified metal is Transferring to the top of the screw conveyor;
A method for purifying a tin alloy, comprising:   Utilizing lead (Pb), which is an impurity in the tin alloy Sn-Ag system containing silver (Ag), Sn-Pb eutectic system having a melting point of 183 ° C and Sn-Ag co-crystal having a melting point of 221 ° C The tin according to claim 14, wherein the operation control temperature is set to 185 to 221 ° C so that a crystal system is formed, and lead (Pb) as an impurity is removed by a recrystallization method. Alloy refining method.   Utilizing lead (Pb) which is an impurity in the tin alloy Sn—Ag—Cu system containing silver (Ag), Sn—Pb eutectic system with a melting point of 183 ° C. and Sn—P with a melting point of 216 ° C. The operation control temperature is set to 185 to 216 ° C so as to form an Ag-Cu eutectic system, and lead (Pb) as an impurity is removed by a recrystallization method. 2. A method for purifying a tin alloy according to 1. Arbitrary work control reference temperature when refining crude tin (Sn) in the screw conveyor is ^{expressed by the} formula Tx = 81.5 ^(logx-1) +150.4
(In the formula, x represents tin (Sn) content% and is applied when the tin content% is 61.9 to 100%, and Tx is the work control reference temperature when the tin content% is x. (° C)
The method for refining a tin alloy according to claim 14, wherein a refining work control temperature range is calculated based on the work control reference temperature.

Images