Monsanto Company

David O Fisher

Mark A Hochwalt

Macaulay S Feld

Leonard F Laskowski

Evan E Thomsen

Gregory J Gervasio

John J Freeman

Dennis J Kalota

Kent P Lannert

John S McConaghy, Jr

Ronald E Zielinski

Chen-Hsyong Yang

John F Freeman

There is disclosed an improved process for the preparation of phosphorus trichloride wherein elemental phosphorus is caused to react with chlorine. The improvement comprises continuous, high speed analysis of the contents of the reactor whereby the reaction is controlled to produce less phosphorus pentachloride and other by-products. The analysis is performed by a laser Raman spectrometer associated with an optrode having a remotely located probe head and a circulating sampling system to continuously provide fresh sample to the probe head continuously. Also disclosed is apparatus for the automatic control of the reaction by control of the reactant feed to the reactor in response to the on-line, continuous analysis of the reactor contents.

Process for preparing phosphorus trichloride

Apparatus for preparing phosphorus trichloride

There is disclosed a process for the controlled hydrolysis of phosphorus trichloride which avoids the formation of lower oxides of phosphorus, phophines and diphosphines wherein phosphorus pentachloride is added to the phosphorus trichloride from about 20 to about 90 percent by weight of the phosphorus trichloride and then water in the form of finely divided droplets is added over the surface of the phosphorus trichloride while the temperature is controlled to below about 80.degree. C.

Hydrolysis of phosphorus trichloride

A method of disposing of wastes containing heavy metal compounds by neutralizing the wastes, oxidizing the neutralized wastes, then solidifying the oxidized wastes using conventional mineral binding agents such as Portland cement. This method is of particular interest in treating arsenic sulfide containing aqueous sludges produced in the manufacture of phosphoric acid.

Method of disposing of wastes containing heavy metal compounds

A perfluorinated polyether having the formula

Vapor phase soldering using certain perfluorinated polyethers

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Chesterfield, MO, United States of America

David O Fisher