Abstract: Finely-divided metal oxides are prepared by the steps of (a) contacting a compound of a metal with a carbohydrate material to obtain an intimate mixture thereof, (b) igniting this mixture to oxidize the same and to insure conversion of substantially all of said metal compound to a fragile agglomerate of its metal oxide, and (c) pulverizing the product of step (b) to form a finely-divided metal oxide powder having a mean particle size below about 1.0 micron. Certain of the finely-divided metal oxide powders produced by this process have the useful property of sinterability at temperatures significantly lower than metal oxide powders heretofore readily available. The powders are useful in the preparation of high strength compacted shapes for use in high temperature and/or corrosive environment, in the preparation of refractory cements, catalysts, catalysts supports and the like.
Abstract: A method for the separation of a light reactive metal (e.g., zirconium) from a heavy reactive metal (e.g., hafnium) by forming insoluble nitrides of the metals in a molten metal solvent (e.g., copper) inert to nitrogen and having a suitable density for the light metal nitride to form a separate phase in the upper portion of the solvent and for the heavy metal nitride to form a separate phase in the lower portion of the solvent. Nitriding is performed by maintaining a nitrogen-containing atmosphere over the bath. The light and heavy metals may be an oxide mixture and carbothermically reduced to metal form in the same bath used for nitriding. The nitrides are then separately removed and decomposed to form the desired separate metals.
Abstract: Synthetic rutile is produced from a titaniferous slag derived from ilmenite. Ilmenite concentrates are reduction smelted to remove iron as a high grade pig iron byproduct and to enrich the remaining slag phase in titanium. Oxidation of the slag and aging at high temperature in the presence of a titanium pyrophosphate flux converts the titanium bearing phases to discrete rutile crystals and a phosphate glass phase containing most of the associated impurities. Rutile is separated from the glassy matrix by attrition scrubbing aged, ground slag in dilute mineral acid solutions.
Type:
Grant
Filed:
December 2, 1975
Date of Patent:
December 7, 1976
Assignee:
The United States of America as represented by the Secretary of the Interior
Abstract: In the clean-up and recovery of isopropanol used to deash polypropylene prepared by the polymerization of propylene in the presence of a TiCl.sub.3.AlCl.sub.3 catalyst, the neutralized bottoms from the first stage of a two stage evaporization of isopropanol are deashed by adding a small quantity of water, which causes flocculation of a substantial portion of the ash in the bottoms which are separated from liquids in the system by centrifuging, with the centrate going to the second stage evaporization in which substantially only amorphous polypropylene is left as bottoms.
Abstract: When titanium phosphate is used as a white pigment to an article of which surface comprises polyolefin composition, the article is remarkably whitened.