High temperature process for making fine magnetic particles

Chemistry of inorganic compounds – Oxygen or compound thereof – Metal containing

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

252 6258, 252 6263, 423634, 423594, C01G 4902, C04B 3226

Patent

active

047770317

ABSTRACT:
The present invention is a method of producing single, unaggregated magnetic iron oxide particles. An iron or iron and divalent metal halide feed solution is kinetically atomized into a high velocity flame. The feed solution is vaporized and held in a reactor at a temperature and partial pressure of an oxidizing phase sufficient to form either ferrous oxide or magnetite particles. The iron or iron and divalent metal halide vapor reacts with the oxidizing phase vapor and converts to either ferrous oxide vapor or magnetite vapor. Since the vapor phase is beyond equilibrium concentration ferrous oxide or magnetite particles precipitate from the vapor phase. Quenching of the magnetite particles at an enhanced rate to less than 500.degree. C. in a reducing atmosphere renders magnetite and in a oxidizing atmosphere renders maghemite. Quenching of the ferrous oxide particles in a non-oxidizing atmosphere produces magnetite particles.

REFERENCES:
patent: 379872 (1943-04-01), Ebner
patent: 2155119 (1939-04-01), Ebner
patent: 2950955 (1960-08-01), Wagner
patent: 3378335 (1968-04-01), Ellis et al.
patent: 4336242 (1982-06-01), Schmidberger et al.
"Ultrafine Metal Oxides by Decomposition of Salts in A Flane", Nielsen et al., Proceeding of the Electrochemical Society Symposium--Ultrafine Particles, May 3, 1961, pp. 181-195.
"Fine Grained Ferrites I. Nickel Ferrite", Malino Fsky et al., Journal of Applied Physics, Supplement to vol. 32, No. 3, Mar. 1961, pp. 237s-238s.
"Spray Roasted Iron Oxide for the Production of Ferrites", Ruthner et al., Ferrite-Proc. of Int'l. Conference, Kyoto, Japan, 1970.
"Fast Reaction Sintering Process for the Production of Ferrites", Ruthner, Journal de Physique, Colloque C1, Supplement No. 4, Apr., 1977, pp. C1-311 to C1-315.
"Preparation of Ferrites by the Atomizing Burner Technique", Wenckus et al., Conference on Magnetism and Magnetic Materials, (IEEE) Publication T-91 (1957), pp. 526-530.
"Sintering of Ferrite Powder Prepared by a New Spray-Roasting Technique", Akashi et al., Sintering and Related Phenomena-Proceedings of International Conference, Jun. 1965, pp. 747-758.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

High temperature process for making fine magnetic particles does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with High temperature process for making fine magnetic particles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High temperature process for making fine magnetic particles will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1957425

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.