JP2003147453A - Low temperature flow-down refining to tin, lead and solder and recycle system for these metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new recycle smelting method with a crucible with high efficiency, in recycling tin, lead and a solder as an alloy thereof in the diversified components. SOLUTION: Tin, lead and the solder alloy containing impurities such as a copper, are charged into a low temperature flow-down furnace and heated to a temperature at not higher than the melting point of the impurities of copper, iron, or nickel, and tin and lead are melted and flown down to remove the impurities in a solid state. Further, many unnecessary added materials and impurities are filtered off by forming copper granular layer in the low temperature flow-down furnace and filtering the copper granular layer because the fluidity of the copper grain is low at the low temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a refining mainly for removing impurities and unnecessary additives in the recycling refining of tin, lead, and alloys of solder.

[0002]

2. Description of the Related Art In the prior art, when refining tin, lead and solder in a crucible, a refined material containing copper was placed on an exhaust flue and allowed to flow at a low temperature to reduce the copper content.

[0003]

In the conventional copper removal by low temperature flow utilizing the residual heat of the crucible refining, the temperature control is difficult because the flue temperature rises in proportion to the refining temperature of the crucible refining. It was not known that impurities could be removed in addition to copper, not just that they could be removed very much. With the widespread use of semiconductors, solder welding now contains not only iron, which was rarely included in recycled solder materials, but also nickel and silicon, which were never included in recycled solder materials. Conventional lead and tin-based solders have been replaced by tin-based lead-free solders, but lead-free solders contain nickel, germanium, etc., and these must be removed. In lead recycling, various components change due to the sophistication of usage technology for tin, lead, and solder, including the fact that calcium is often contained. With the progress of solder welding technology, even the interposition of metal oxides such as tin and lead, which have not been a problem until now, became a problem.

[0004]

[Means for Solving the Problems] In order to solve the above problems, a dedicated low-temperature downflow furnace (basic structure is the same as that of a reflection furnace) for removing additives and impurities is manufactured, and tin, lead, and solder are used as melting points. Impurities, additives, and metal oxides are not only removed by low-temperature flow at a similar temperature, but also an appropriate amount of copper is melted and added to the refining of recycled materials with or without a small copper content in the recycled materials. As a result, tin, lead, and copper molecules in solder can be used as a filter to completely remove the above-mentioned additive impurities.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a dedicated low-temperature downflow furnace for tin, lead, and solder was produced in order to thoroughly control temperature.

When the recycled material of tin, lead, and solder contains an appropriate amount of copper and iron iron, nickel, silicon, germanium, calcium, metal oxide, etc., and when the amount of copper does not reach the appropriate amount. Melt and add an appropriate amount of copper.

In front of the metal discharge port, a resistance material such as refractory brick is installed for the falling metal.

[0008] The recycled material made into a base metal is put into a low temperature down-flow furnace and is made to flow down at low temperature. When the input base metal is tin or a lead alloy (solder), a large amount of tin having a low melting point flows down first, so the amount of tin in the flow-down solder that flows down first is higher than that of the input base metal.

When the amount of metal flowing in the low-temperature flow furnace decreases,
Gradually raise the temperature. At this time, as the temperature of the flowing metal increases, the tin content having a lower melting point decreases and the lead content having a higher melting point than tin increases.

When the copper content starts to flow down, the downflow refining is stopped,
The remaining copper-containing metal is taken out.

If the necessary removal components are not sufficiently removed,
Repeated low temperature smelting.

[Examples] The practice is to circulate and recycle recovered recycling materials such as tin, lead, solder base metal, their solvent-containing metal lees, and metal containing foreign substances according to the following procedure.

Solvent incineration of recycled materials in an incinerator.
By incineration, (A) primary base metal is produced and other by-products are produced. Product- (A) Primary base metal By-product- (B)
Metal oxide ash (C) Metal foreign material

In the low temperature down-flow furnace, the (A) primary base metal is flown down at low temperature to remove the removable components. Product- (D) Secondary base metal By-product- (E) Copper-containing alloy

(B) Metal oxide ash is reduced at a high temperature in a reducing furnace to produce (A) primary base metal. Product- (A) Primary base metal By-product- (F) Metalloro

The (A) primary base metal produced in the above reduction furnace is reprocessed in the low temperature flow furnace (D) into the secondary base metal.

The residual copper component is removed from the secondary base metal (D) by a chemical reaction with sulfur in a component adjusting furnace. Product- (G)
Recycled metal byproduct- (H) decopper residue

The above (H) decoppered residue is reprocessed in a reducing furnace (A) into a primary base metal.

The above (A) primary base metal is re-processed in a low temperature downflow furnace (D) into a secondary base metal.

The above (D) secondary base metal is used as a component adjusting furnace (G) recycled base metal.

Dust collecting ash of the dust collector is generated in the incinerator reduction furnace. (In-plant cleaning ash is also included in dust collection ash)

[0021]

The present invention is carried out in the above-mentioned modes,
By utilizing the low temperature down-flow furnace as a part of the circulation recycling system for tin, lead and solder, the following effects can be obtained.

By the low-temperature down-flow furnace, most of the above-mentioned additives and impurities required for removal can be kept below the allowable limit of tin, lead and solder impurities specified in Japanese Industrial Standards. Moreover, even if impurities of components not listed in Japanese Industrial Standards can be removed to less than 0.01%, the utility value of recycled metal is increased and the range of its use is expanded.

By incorporating a low temperature down-flow furnace into the above circulation type recycling system, a circulation type recycling system which does not generate industrial waste was completed.

From the above products and by-products, (A) primary base metal (B) metal oxide ash (D) secondary base metal (H) decopper residue is circulated and refined in the factory.

The products sold and reused from the above-mentioned products and by-products are (C) foreign metal (E) copper-containing alloy (F) metal noro (G) recycled metal (I) dust ash

From (A) to (I), all of them are recycled by being reprocessed or sold and used.

[Explanation of symbols]

1 (1) to (7) Materials that can be removed by a low temperature down-flow furnace. 2 to recycling type, recycling material processing equipment. 3 (A) to (I) Materials that are reprocessed in-house, and materials that are sold to others.

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Claims (8)

[Claims] 1. A low-temperature down-flow smelting process of tin, lead and solder, which is an alloy thereof, in a low-temperature down-flow furnace. 2. Identification of a removable substance in low-temperature smelting of solder, which is an alloy of tin, lead and their alloys, in a low-temperature down-flow furnace (1) copper (2) iron (3) nickel (4) germanium (5) silicon ( 6) Calcium (7) Metal oxides such as tin and lead 3. A filter effect by copper particles, which is related to a substance to be removed in refining metal, by melting and adding copper to a low-temperature flowing-down refining material. 4. A copper particle filter which is provided with a refractory brick or the like in front of a metal discharge port of a low-temperature down-flow furnace, which gives resistance to the downflow and collects copper particles having poor fluidity to form a thick copper particle metal layer. The filter effect of. 5. In the recycling and refining of tin, lead and solder,
By incorporating the low temperature down-flow furnace into the recycling system,
Completion of a recycling system that does not generate industrial waste. 6. Increased removal of unnecessary additives and impurities by repeated downflow refining of tin, lead and solder in a low temperature downflow furnace. 7. Concentration of tin in tin-lead solder by utilizing the melting point in low-temperature smelting of solder. 8. A lead content concentration of tin-lead solder, which utilizes a melting point in low-temperature smelting of solder.