Continuous rotary kiln calcination of YBaCuO precursor powders

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00026a038· OSTI ID:7233612

Shelukar, S D; Sundar, H G.K.; Semiat, R; Richardson, J T; Luss, D ^[1]

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1. Univ. of Houston, TX (United States)

A bench rotary kiln was used to produce pure YBa[sub 2]Cu[sub 3]O[sub 6+x] by continuous calcination of spray-roasted precursor powder using a countercurrent air flow to avoid a reaction between evolved CO[sub 2] and the product. Product agglomeration caused a spread in the velocity distribution, requiring the use of extra calcination for a pure product. High-purity YBa[sub 2]Cu[sub 3]O[sub 6.6] was obtained at 940 C for 0.9 vol% solid loading, an average residence time of 75 min, and N[theta] (N = rotation rate, [theta] = inclination) between 3 and 4.5 rpm deg. However, at a residence time of 77 min, increased product agglomeration at 2.5 rpm deg caused incomplete conversion to YBa[sub 2]Cu[sub 3]O[sub 6.6]. Increasing the average residence time above 75 min increased the oxygen content of the product, with pure orthorhombic YBa[sub 2]Cu[sub 3]O[sub 6.9] forming at 160 min. Due to reaction and temperature induced changes in particle size and shape, existing correlations cannot predict the dependence of the average solid residence time on the operating conditions.

• OSTI ID: 7233612
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 33:2; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CALCINATION
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER COMPOUNDS
COPPER OXIDES
DECOMPOSITION
HIGH-TC SUPERCONDUCTORS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
SUPERCONDUCTORS
SYNTHESIS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES