Modified process for refining niobium by electron beam
Creators
- 1. Universidade Estadual de Campinas (Brazil). Inst. de Fisica
- 2. Fundacao de Tecnologia Industrial, Sao Paulo (Brazil)
- 3. Sao Paulo Univ. (Brazil). Escola Politecnica
Description
The experimental results, thermodynamic equilibrium and kinetic theory of the metal/gas interaction in refractory metals are reviewed. The adsorption and desorption of nitrogen, hydrogen and CO are reversible, whereas those of oxygen are irreversible, with adsorption of an oxygen atom and volatilisation of the metal oxide. Based upon this fact, a new electron beam refining technology is proposed for niobium, consisting of four points: preparation of an electrode by aluminothermic reduction; zone refining in the first melt; kinetic refining in subsequent melts and compact design of the refining plant. Experimental results from a 300 kW pilot plant were in complete agreement with the technology proposed, giving 2.4 times the productivity predicted by the conventional technology. (Author)
Abstract (Portuguese)
Sao revisados os resultados experimentais, teoria termodinamica de equilibrio e teoria cinetica de interacao metal-gas nos metais refratarios. O processo de absorcao e degaseificacao do nitrogenio, hidrogenio e CO e reversivel, enquanto o do oxigenio e irreversivel, com absorcao do atomo de oxigenio e volatilizacao do oxido metalico. Baseando-se neste fato e proposta uma nova tecnologia de refino de niobio por feixe eletronico a partir de quatro pontos, preparacao de eletrodo reduzido por aluminotermia; refino por zona na primeira fusao; refino cinetico nas fusoes subsequentes; configuracao compacta da instalacao do refino. Resultados experimentais numa instalacao piloto de 300 kW mostraram concordancia completa com a tecnologia proposta, fornecendo produtividade 2,4 vezes maior que a prevista pela tecnologia convencional. (Autor)Additional details
Additional titles
- Original title (Portuguese)
- Processo modificado de refino de niobio por feixe eletronico
Publishing Information
- Journal Title
- Metalurgia (Sao Paulo)
- Journal Volume
- 38
- Journal Issue
- 299
- Series
- Metalurgia (Sao Paulo).
- Journal Page Range
- 591-597
- ISSN
- 0026-0983
Conference
- Title
- 36. Annual Congress of the Brazilian Association of Metals.
- Dates
- 5 Jul 1981.
- Place
- Recife, PE (Brazil).
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 14771326
- Subject category
- S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- COMPARATIVE EVALUATIONS; ELECTRON BEAMS; NIOBIUM; PILOT PLANTS; REFINING; REFRACTORIES; ZONE REFINING
- Descriptors DEC
- BEAMS; ELEMENTS; FUNCTIONAL MODELS; LEPTON BEAMS; METALS; PARTICLE BEAMS; SEPARATION PROCESSES; TRANSITION ELEMENTS