Claims
- 1. A method of treating an aluminum-processing fused slag containing water-soluble salts, corundum, spinel and quartz in a major proportion and metallic aluminum in a minor proportion, said method comprising the steps of:
- (a) crushing said aluminum-processing fused slag containing water-soluble salts, corundum, spinel and quartz in a major proportion and metallic aluminum in a minor proportion, by an impact crusher and sieving the resulting crushed slag in a first two-stage sieving apparatus, from said first sieving apparatus recovering a first metallic aluminum fraction having particle sizes above 25 mm and a content of metallic aluminum about 98 percent, a first intermediate fraction with particle sizes between 0.5 and 25 mm, and a first fine slag fraction having particle sizes below 0.5 mm;
- (b) crushing said first intermediate fraction by a multi-rotor hammer mill and sieving the crushed fraction from said mill in a second two-stage sieving apparatus, from said second sieving apparatus recovering a second metallic aluminum fraction having particle sizes above 8 mm and a content of metallic aluminum above 98 percent, a second intermediate fraction with a particle sizes between 0.5 and 8 mm, and a second fine slag fraction having particle sizes below 0.5 mm;
- (c) crushing said second intermediate fraction by a first roll crusher and sieving the crushed fraction from said first roll crusher in a third two-stage sieving apparatus, from said third sieving apparatus recovering a third metallic aluminum fraction with particle sizes above 3 mm and a content of metallic aluminum above 98 percent, a third intermediate fraction with particle sizes between 0.5 and 3 mm, and a third fine slag fraction having particle sizes below 0.5 mm;
- (d) crushing said third intermediate fraction by a second roll crusher and sieving the crushed fraction from said second roll crusher, from said sieving recovering a fourth metallic aluminum fraction with an aluminum content of above 80% and particle sizes above 0.6 mm and a fourth fine slag fraction with particle sizes below 0.6 mm,
- (e) feeding water and said first, second, third and fourth fine slag fraction into a leaching vessel and in said vessel continuously dissolving the water-soluble constituents of said slag fractions to form an aqueous suspension, said suspension being in contact with said slag fractions for a residence time of two to four hours;
- (f) from said leaching vessel separately withdrawing evolved gases and said suspension, filtering said withdrawn suspension and evaporating water from the filtered solution; and
- (g) scrubbing said evolved gases with aqueous sulfuric acid and then passing the gases over an active carbon absorber.
- 2. The method defined in claim 1 wherein ball mill dust is fed into said leaching vessel.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3137950 |
Sep 1981 |
DEX |
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Parent Case Info
This is a continuation of co-pending application Ser. No. 797,181 filed on Nov. 8, 1985, which is a continuation of application Ser. No. 684,977 filed on Dec. 21, 1984, which is a continuation of application Ser. No. 421,241, filed Sept. 22, 1982, all of which are now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1669327 |
Oct 1969 |
DEX |
2853256 |
Apr 1979 |
DEX |
2746860 |
Dec 1979 |
DEX |
Non-Patent Literature Citations (1)
Entry |
A Dictionary of Metallurgy, pp. 63 and 324, 6/17/59. |
Continuations (3)
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Number |
Date |
Country |
Parent |
797181 |
Nov 1985 |
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Parent |
684977 |
Dec 1984 |
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Parent |
421241 |
Sep 1982 |
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