AU619849B2 - Pre-melting treatment process for reproducing aluminum - Google Patents

Description

11 L i ,L i i r

AUSTRALIA

Patents Act 619849 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Applicant(s): Yamaichi Kinzoku Company Limited 715 Honjyuku Nagaizumi, Sunto-District, Shizuoka, JAPAN Susono Light Metal Company Limited Hiramatu Susono, Shizuoka, JAPAN Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: PRE-MELTING TREATMENT PROCESS FOR REPRODUCING ALUMINUM Our Ref 136211 POF Code: 104296/104309,104317 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1 6006 r

SPECIFICATION

PRE-MELTING TREATMENT PROCESS FOR REPRODUCING

ALUMINUM

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BACKGROUND OF THE INVENTION The present invention relates to a re-melting treatment process for reproducing aluminum, for example, Aluminum alloy 3004 from used aluminum cans.

Nowadays, aluminum cans containing various juices and beer are mass-produced by using composite metal of aluminum, such as aluminum alloy (hereinafter referred as aluminum simply) and very thin synthetic resin film coated on a surface of the aluminum cans. The very thin synthetic resin may comprise a printed trademark, picture, company name or the like applied by paint. The paint quite often contains titanium. Most of the aluminum cans used have been recovered or recycled. The aluminum cans recovered are shattered or powdered producing scale-like pieces of a predetermined size. The aluminum pieces are melted after removing iron pieces, trash and sand from the pieces, reproducing aluminum material.

According to the shortcomings of the prior art, the yield rate of melting and reproducing aluminum is considerably low and impurities such as titanium and carbide are remained or contained in the reproduced aluminum, resulting in a low purity of the aluminum reproduced.

In addition, it has been disadvantageously necessary to consume a large quantity of energy in order to melt the aluminum chips before reproducing aluminum purified.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an aluminum reproducing process which overcomes or alleviates any shortcomings of the conventional aluminum reproducing process from aluminum cans used.

o* \"NT0a* 1A gi -I 1 According to the present invention, there is provided a pre-melting treatment process for producing aluminum from used aluminum cans or used aluminum alloy cans comprising the steps of pulverizing used aluminum cans or used aluminum alloy cans into aluminum chips, separating and removing impurities such as dust, sand, iron chips and the like from the aluminum chips, o o o 0 ooo oo 090 0 0 0 0 9 o o0 1 oo o o 00oo 00 e a incinerating the synthetic resin and paint attached to said aluminum chips.

heating these chips to the temperature of a range of 300 C to 350 C, applying twisting and impact pressure force to the heated aluminum chips in order to form substantially spherical aluminum granules and simultaneously removing impurities such as carbide and titanium remaining from the synthetic resin and paint on the aluminum chips.

0)00 00 0 3 9 00000 o a 1) o 000 -00 0 o 0 o0 0 lB f4 ~N h~ceu;rrt~-P~TZe---~ 1 1 It is the third purpose of the present invention to j provide an aluminum reproducing process in which the aluminum l can be reproduced with a little energy.

All the three purposes above are attained according to the present invention providing the unique aluminum reproducing which comprises a step of pulverizing aluminum cans used or discarded along roads int- scale-like aluminum chips, a step of separating rubbish rtter, sand, and metal chips from the aluminum chips a/ removing them, a step of burning I up or incinerating an synthetic resin attached to these S aluminum chips orprieces, astep of heating these chips in a S range of about/3Oc -about 350c softening them, a step of applying twisting and pressing force to the softened aluminum chips iorder to tear off any impurities, such as carbide :n.

titanium remained unremoved and unburned, granulating Again, the reproducing yield of aluminum in the prei melting treatment process according to the present invention is considerably improved compared to that in the conventional treatment process resulting in more volume of aluminum reproduced than the conventional process. To the aluminum reproduced by the present invention, a twisting and pressing force is applied to separate and remove impurities of titaniirm and carbide raising the purity of the aluminum reproduced.

I It is noted that the volume of energy to be consumed in the Sunique premelting treatment process of the present invention is very little since the aluminum chips are heated to only be soften without melting them.

BRIEF DESCRIPTION OF THE DRAWING Next, a preferred embodiment of the pre-melting treatment process of the present invention for reproducing aluminum from used aluminum cans will be explained with h reference to the enclosing drawing of the solo figure depicting a diagramatic view of one of the pre-melting treatment processes above.

DESCRIPTION OF THE PREFERRED EMBODIMENT First, anumber of used aluminum cans and the like are entered to a pulverizer 1 and they are pulverized. Only the chips of less than 30 mm in length are passed through a sieve l'of 30 mm in diameter, which is installed on the P interior of the pulverizer 1 at near its bottom.

The aluminum chips passed through the sieve 1' are transferred aerodynamically to a cyclone 3 along with air wind pressed by a blower 2. These chips rotate at a high speed in the cyclone 3 to separate dust and sand and the like attached on the aluminum chips and make fine powder of paint chips and the like of less than 100 micron in diameter and gas generated by evaporation of paint stuck to the aluminu chips sucked through a bag filter 4, removing them.

Aluminum chips discharged from the cyclone 3 and the i impurities of rubbish and dust previously separated arn supplied to a sieving device 5 removing the impurities from the aluminum chips. Then, the aluminum chips are sent to a i magnetic separator 6.

i Any iron chips blended with the aluminum chips are separated from the chips of aluminum in the magnetic sepatator S6 and removed from the separator. The aluminum chips are aerodynamically sent to the storage tank 7.

The aluminum chips stored in the tank 7 are transferred to a heat treating machine 8 by means of a screw conveyor i (not shown). The volume of aluminum chips to be sent to the i heat treatment machine 8 is suitably so controlled as to burn at any synthetic resin and the like stuck to the aluminum i chips in the machine 8. When a burning temperature in the r heat treatment machine 8 is lowered than the predetermined one, for example, 200C, it is necessary to supply oil or fuel to the machine 8. When the burning temperature is higher than the predetermined one, water spraying is need to cooldown the Sinterior of machine. Consequentlyafter synthetic resin stuck to aluminum chips are burned out in the heat treatment machine 8 of a suitable temperature, the aluminum chips are heated to about 330A by meanes of a burner 8'installed on the machine S8.

i The heated aluminum chips are supplied to an impacttype granulating machine 9 functionally or operatively connect(i to the heat treating machine 8. The impact-type granulating machine 9 has a fixed impact body (not shown) and a rotary impact body (not shown), respectively installed in the granulating machine 9 so as to form a gap between both bodies.

Impact is applied to the aluminum chips in the granulating machine 9 through these fixed and rotary impact bodies, as a result impurities such as titanium and carbide are further separated from the aluminum chips improving or raising the purity of alminum reproduced. The elongation of the heated l aluminum chips is make five times of that of an aluminum at i a room temperature, so that impact applied to the heated aluminum chips makes them twisted and pressed between the fixed or stationary impact body and the rotary body not becoming broken or powdered. In other words, the aluminum chips are shredded and tore making a number of granulated aluminum of about 11 mm in diameter when they pass through between both bodies installed in the impact-type granulating machine 9.

The relation of the diameter of granulated aluminum to the scale-like aluminum chips pulverized in the pulverizer 1 is shown by the following equation.

2 3A C R which is developed I- 4 7 A 3C wherein diameter of granulated aluminum R substantially equals to the distance of gap between the stationary and rotary impact bodies length and width of aluminum chip A thickness of aluminum chip C A also equals to about the maximum mesh size of the sieve 1'.

Various shapes, such as rectangular, square, and round of the aluminum chips are appropriately used.

According to the embodiment above of the present invention, the maximum mesh size of the sirve 1' is 30 mm in di: It is, however, permitted to suitably use the particular sizes of a range from about 6 mm to 60 mm of the mesh size of the sieve The experiment shows that the suitable temperature of aluminum chips heated to soften them is in the range of According to the experiments carried arding the present invention, a repr e- gyieid of aluminum was 96 since alu cips of 100 kg was consumed to reproduce g 3-nmof_ 96_kg r gtc the'ii--= 300 C to 350 0

C.

According to the experiments carried out regarding the present invention, a reproducing yield of aluminum was 96 since aluminum chips of 100 kg was consumed to reproduce granulated aluminum of 96 kg. According to the Sconventional o to at 000 S 0 0 5A pre-melting process, only 85 kg of aluminum has been reproduced from 100 kg of aluminum chips, so that the reproducing yield of aluminum has been 85%. Comparing the premelting process of the present invention to the conventional pre-melting process, the aluminum reproducing yield of the present invention exceeds that of the conventional process by so high as 11%.

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Claims (2)

1. A pre-melting treatment process for producing aluminum from used aluminum cans or used aluminum alloy cans comprising the steps of pulverizing used aluminum cans or used aluminum alloy cans into aluminum chips, separating and removing impurities such as dust, sand, iron chips and the like from the aluminum chips, f f 41 I 0 0 0t 2 *r I

4. 1 25 11*4, incinerating the synthetic resin and paint attached to said aluminum chips. heating these chips to the temperature of a range of 300 C to 350°C, applying twisting and impact pressure force to the heated aluminum chips in order to form substantially spherical aluminum granules and simultaneously removing impurities such as carbide and titanium remaining from the synthetic resin and paint on the aluminum chips. 2. A process according to claim 1, substantially as herein described with reference to the accompanying drawing. DATED: 19 November 1991 PHILLIPS ORMONDE FITZPATRICK 4 *S Attorneys for: YAMAICHI KINZOKU CO., LTD. and SUSONO LIGHT METAL CO., LTD. 2394Z 7