Recycling of aluminum salt cake
The secondary aluminum industry generates more than 110 {times} 10{sup 3} tons of salt-cake waste every year. This waste stream contains about 3--5% aluminum, 15--30% aluminum oxide, 30--40% sodium chloride, and 20--30% potassium chloride. As much as 50% of the content of this waste is combined salt (sodium and potassium chlorides). Salt-cake waste is currently disposed of in conventional landfills. In addition, over 50 {times} 10{sup 3} tons of black dross that is not economical to reprocess a rotary furnace for aluminum recovery ends up in landfills. The composition of the dross is similar to that of salt cake, except that it contains higher concentrations of aluminum (up to 20%) and correspondingly lower amounts of salts. Because of the high solubility of the salts in water, these residues, when put in landfills, represent a potential source of pollution to surface-water and groundwater supplies. The increasing number of environmental regulations on the generation and disposal of industrial wastes are likely to restrict the disposal of these salt-containing wastes in conventional landfills. Processes exist that employ the dissolution and recovery of the salts from the waste stream. These wet-processing methods are economical only when the aluminum concentration in that waste exceeds about 10%. Argonne National Laboratory (ANL) conducted a study in which existing technologies were reviewed and new concepts that are potentially more cost-effective than existing processes were developed and evaluated. These include freeze crystallization, solvent/antisolvent extraction, common-ion effect, high-pressure/high-temperature process, and capillary-effect systems. This paper presents some of the technical and economic results of the aforementioned ANL study.
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 6361359
- Report Number(s):
- ANL/CP-73449; CONF-911265--1; ON: DE92003408
- Country of Publication:
- United States
- Language:
- English
Similar Records
An economic and technical assessment of black-dross and salt-cake-recycling systems for application in the secondary aluminum industry
An economic and technical assessment of black-dross and salt-cake-recycling systems for application in the secondary aluminum industry
Related Subjects
320305* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Industrial Waste Management
ALKALI METAL COMPOUNDS
ALUMINIUM
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
COST
CRYSTALLIZATION
ECONOMIC ANALYSIS
ECONOMICS
ELEMENTS
EXTRACTION
HALIDES
HALOGEN COMPOUNDS
MANAGEMENT
MATERIALS RECOVERY
METALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
PRECIPITATION
PROCESSING
RECOVERY
RECYCLING
SEPARATION PROCESSES
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLUBILITY
SOLVENT EXTRACTION
WASTE MANAGEMENT
WASTE PROCESSING