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Title: Advanced preparation of ceramic powders

Abstract

A process is described for the preparation of sinterable metal oxide ceramic powders, comprising the steps of: (a) forming a first solution of an ammonia donor in a water-miscible organic liquid and a second solution of salts of all the metals whose oxides are present in the metal oxide ceramic powders, the second solution also containing sufficient water to produce by reaction with the ammonia donor in the first solution a sufficient amount of ammonia to precipitate at least part of the cations of the metal salts in the second solution when such ammonia is released into the second solution; (b) mixing the first solution and the second solution while maintaining a temperature of at least 60/sup 0/C in the reaction vessel, so as to form a solid precipitate containing at least part of the ceramic metal content originally in the second solution; (c) treating the solid precipitate with alkali for a sufficient time to prevent discoloration of the precipitate upon subsequent heating to 400/sup 0/C; (d) neutralizing the alkali remaining after the treating of part (c) to produce a pH of 7.0 +. 0.2 in the liquid phase in contact with the solid precipitate; (e) separating the solid phasemore » remaining after part (d) from the bulk of the liquid phase present therewith after part (d); (f) washing the solid phase remaining after part (e) with sufficient aqueous ammonia to remove substantially all the soluble inorganic matter and the last traces of organic matter from the solid phase, (g) drying and calcining the solid phase remaining after part (f) by heating it for a sufficient time at a temperature sufficient to yield a stable crystal phase and degree of hydration if any for sintering but not so high as to cause appreciable sintering or coarsening of particle size in the solid phase.« less

Inventors:
Publication Date:
OSTI Identifier:
5348623
Patent Number(s):
US 4605631
Assignee:
Norton Co., Worcester, MA
Resource Type:
Patent
Resource Relation:
Patent File Date: Filed date 19 Mar 1984
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CERAMICS; CHEMICAL PREPARATION; AMMONIA; AQUEOUS SOLUTIONS; CALCINATION; CHEMICAL REACTION YIELD; DRYING; HEATING; HIGH TEMPERATURE; HYDRATION; MEDIUM TEMPERATURE; METALS; MIXING; OXIDES; PARTICLE SIZE; PH VALUE; POWDERS; SINTERED MATERIALS; SINTERING; SOLUBILITY; WASHING; WATER; CHALCOGENIDES; CHEMICAL REACTIONS; CLEANING; DECOMPOSITION; DISPERSIONS; ELEMENTS; FABRICATION; HYDRIDES; HYDROGEN COMPOUNDS; MATERIALS; MIXTURES; NITROGEN COMPOUNDS; NITROGEN HYDRIDES; OXYGEN COMPOUNDS; PYROLYSIS; SIZE; SOLUTIONS; SOLVATION; SYNTHESIS; THERMOCHEMICAL PROCESSES; YIELDS; 360201* - Ceramics, Cermets, & Refractories- Preparation & Fabrication

Citation Formats

Rossi, G A. Advanced preparation of ceramic powders. United States: N. p., 1986. Web.
Rossi, G A. Advanced preparation of ceramic powders. United States.
Rossi, G A. 1986. "Advanced preparation of ceramic powders". United States.
@article{osti_5348623,
title = {Advanced preparation of ceramic powders},
author = {Rossi, G A},
abstractNote = {A process is described for the preparation of sinterable metal oxide ceramic powders, comprising the steps of: (a) forming a first solution of an ammonia donor in a water-miscible organic liquid and a second solution of salts of all the metals whose oxides are present in the metal oxide ceramic powders, the second solution also containing sufficient water to produce by reaction with the ammonia donor in the first solution a sufficient amount of ammonia to precipitate at least part of the cations of the metal salts in the second solution when such ammonia is released into the second solution; (b) mixing the first solution and the second solution while maintaining a temperature of at least 60/sup 0/C in the reaction vessel, so as to form a solid precipitate containing at least part of the ceramic metal content originally in the second solution; (c) treating the solid precipitate with alkali for a sufficient time to prevent discoloration of the precipitate upon subsequent heating to 400/sup 0/C; (d) neutralizing the alkali remaining after the treating of part (c) to produce a pH of 7.0 +. 0.2 in the liquid phase in contact with the solid precipitate; (e) separating the solid phase remaining after part (d) from the bulk of the liquid phase present therewith after part (d); (f) washing the solid phase remaining after part (e) with sufficient aqueous ammonia to remove substantially all the soluble inorganic matter and the last traces of organic matter from the solid phase, (g) drying and calcining the solid phase remaining after part (f) by heating it for a sufficient time at a temperature sufficient to yield a stable crystal phase and degree of hydration if any for sintering but not so high as to cause appreciable sintering or coarsening of particle size in the solid phase.},
doi = {},
url = {https://www.osti.gov/biblio/5348623}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1986},
month = {8}
}