Process for insolubilizing and consolidating spent linings from hall-heroult electrolysis cells
US5947888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1997 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Nov 25, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/91
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Process for insolubilizing and consolidating in pellet form the spent linings from electrolysis cells for the production of aluminium comprising grinding said spent linings and mixing them thoroughly with various pulverulent refractory additives before heating, characterized in that after the addition of: PA1 a first additive intended to fix the alkali metals during firing, which is chosen from the group of aluminosilicates, PA1 and subsequently a second additive intended firstly to combine with the impregnating fluoride compounds during firing to form new stable, insoluble compounds, and secondly through its non-combined excess part to assure the consolidation of the mixture, and is chosen from the group of calcium oxides and salts, preferably limestone cements and mortars, PA1 the intimate mixture of ground, spent linings and said first and second pulverulent additives is agglomerated into pellet form before firing at a temperature in the range of from 700.degree. C. to 950.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.