Patent · US Expired

Method for the treatment of red mud

US3989513A · kind A · utility

7Cited by
9References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 11, 1975
Grant dateNov 2, 1976
Priority date
Expiry dateMar 11, 1995

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S75/958
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Disclosed is a method for the treatment of the red mud byproduct of the Bayer aluminum process, wherein limestone, hydrated lime or other CaO-containing material is added to the red mud in certain molar proportions to the ingredients of the red mud, then the mixture is further mixed with a reducing agent, and the entire mixture is subjected to a reducing heat treatment during the course of which the mix becomes softened or molten. The iron and the slag are separated from each other while the mix is still molten, or after it has been cooled, and then the Na and Al-content of the slag is extracted with a sodium carbonate solution containing a caustic, or with a sodium carbonate solution and a solution of a caustic in two steps.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.