NIOSHTIC-2 Publications Search

Atmospheric pressure desilication of leach liquors from lime-sinter processing of anorthosite.

Authors
Hayashi-M
Source
Bureau of Mines 1982; :1-14
Link
NIOSHTIC No.
10006400
Abstract
The Bureau of Mines conducted laboratory studies to investigate methods for desilicating sodium aluminate solution derived from leaching a limestone-anorthosite sinter with 10-pct na2co3 solution. Desilication tests were made at atmospheric pressure to determine the effects of time and additions of lime and desilication residues. A two-stage, countercurrent desilication procedure was developed to reduce the sio2 content sufficiently to meet specifications for cell- grade al2o3. Both stages were conducted at boiling temperatures at atmospheric pressure. Reagent lime was charged as desilication seed to the partially desilicated solution in the second stage, and a product (desilication residue) precipitated by the lime addition was charged to the freshly leached solution in the first stage. Average al2o3 loss in the desilication circuit was 5.8 pct, and the product solution contained less than 0.04 G/l sio2. Complete precipitation of al2o3 by carbonation resulted in a hydrate containing less than 0.01 pct sio2. Calcination of this hydrate would produce al2o3 meeting the 0.015 pct sio2 specification for cell-grade materials.
Keywords
Mining; Sodium compounds; Limestone; Limestone mines; Laboratory testing; Reagents; Chemical processing
CAS No.
1302-42-7; 1317-65-3
Publication Date
19820101
Document Type
IH; Report of Investigations
Fiscal Year
1982
Identifying No.
RI 8713
NIOSH Division
SLRC
Source Name
Bureau of Mines
State
UT
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division