Zirconium and uranium recoveries from a ZrSiO$sub 4$ and ZrO$sub 2$ mineral (Caldasito) from the Pocos de Caldas Plateau, the State of Minas Gerais, Brazil (in Portuguese)
Thesis/Dissertation
·
OSTI ID:4375842
Thesis. A commercial-gnade zirconium dioxide (Zr, Hf)O/sub 2/ and a sodium diuranate (SDU) or ammonium diuranate (ADU) processing is presented. These compounds are obtained from the Caldasito, from the Pocos de Caldas Plateau in the southern part of the State of Minas Gerais, Brazil. The processing scheme is developed in three steps: the chemical opening of the ore, the uranium- zirconium separation and the zirconium purification. The uranium-zirconium sepanation takes place by a liquid-liquid extraction in the TBP-varsol-HNO/sub 3/- H/sub 2/O system, using as organic phase a mixtare of TBP 36% v/v-varsol. The yield of the uranium extraction, in a single and discontinuous stage is higher than 80% in U/sub 3/O/sub 8/. The zirconium extraction by the tributyl phosphate (TBP) in dilute nitric acid is negligible. The raffinate (zirconyl nitrate) is purified by an ion-exchange operation with a strong cationic resin. Aluminium, titanium, and iron are the most important impurities in the aqueous solution. The zirconium nitrate is transformed into a colloidal solution, the zirconium being not retained by the column. The zirconium in the effluent is precipitated by ammonium hydroxide and calcined to a commercialgrade zirconium dioxide. By this procedure it is possible to produce a commercial-grade oxide higher than 97% in ZrO/sub 2/. (INIS)
- Research Organization:
- Sao Paulo Univ. (Brazil). Escola Politecnica
- NSA Number:
- NSA-29-012551
- OSTI ID:
- 4375842
- Report Number(s):
- INIS-mf--943
- Country of Publication:
- Brazil
- Language:
- Portuguese
Similar Records
Brazilian uranium mine decommissioning-chemical and radiological study of waste rock piles
How Stakeholder Engagement is Evolving at the Caldas Uranium Mining Site in Minas Gerais, Brazil - 13223
PREPARATION OF UO$sub 2$ FOR USE IN CERAMIC FUELS. PART II. CONTINUOUS PRECIPITATION OF AMMONIUM DIURANATE
Journal Article
·
Mon Dec 30 23:00:00 EST 1996
· Transactions of the American Nuclear Society
·
OSTI ID:436863
How Stakeholder Engagement is Evolving at the Caldas Uranium Mining Site in Minas Gerais, Brazil - 13223
Conference
·
Mon Jul 01 00:00:00 EDT 2013
·
OSTI ID:22224813
PREPARATION OF UO$sub 2$ FOR USE IN CERAMIC FUELS. PART II. CONTINUOUS PRECIPITATION OF AMMONIUM DIURANATE
Technical Report
·
Sun Jun 01 00:00:00 EDT 1958
·
OSTI ID:4272077
Related Subjects
*AMMONIUM URANATES-- PRODUCTION
*SODIUM URANATES-- PRODUCTION
*URANIUM-- SOLVENT EXTRACTION
*ZIRCONIUM OXIDES-- PRODUCTION
*ZIRCONIUM-- SOLVENT EXTRACTION
ADU
AMMONIUM HYDROXIDES
ION EXCHANGE
N40240* --Chemistry--Inorganic
Organic
& Physical Chemistry--Feed Materials Processing
N50120 --Metals
Ceramics
& Other Materials--Ceramics & Cermets--Preparation & Fabrication
NITRIC ACID
ORE PROCESSING
PURIFICATION
TBP
URANATES
URANIUM OXIDES U3O8
WATER
*SODIUM URANATES-- PRODUCTION
*URANIUM-- SOLVENT EXTRACTION
*ZIRCONIUM OXIDES-- PRODUCTION
*ZIRCONIUM-- SOLVENT EXTRACTION
ADU
AMMONIUM HYDROXIDES
ION EXCHANGE
N40240* --Chemistry--Inorganic
Organic
& Physical Chemistry--Feed Materials Processing
N50120 --Metals
Ceramics
& Other Materials--Ceramics & Cermets--Preparation & Fabrication
NITRIC ACID
ORE PROCESSING
PURIFICATION
TBP
URANATES
URANIUM OXIDES U3O8
WATER