Cabot Corporation

About: Cabot Corporation is a company organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Carbon black & Carbon. The organization has 1279 authors who have published 1399 publications receiving 36736 citations.

Tantalum powders and methods of producing same

Abstract: Methods of forming tantalum powders and other valve metal powders are described. The method involves high impact milling a starting powder in a fluid medium and optionally a milling media using a high energy mill. The methods of the present invention have the ability to reduce DC leakage and/or increase capacitance capabilities of valve metal powders when formed into capacitor anodes. The methods of present invention further reduce the milling time necessary to form high surface area valve metal powders and leads to reducing contaminant levels in the valve metal powders. The process is particularly well-suited for forming metal flakes, such as tantalum or niobium flakes, of high purity.

High chromium nickel base alloys

Abstract: Disclosed is a nickel-base alloy which provides excellent corrosion resistance to a variety of severe environments, especially hot phosphoric acid. The alloy preferably contains, in weight percent: about 30 chromium, about 4 molybdenum, about 2 tungsten, about 1 Cb/Ta, about 1.5 copper, about 14 iron and the balance nickel plus the impurities and modifying elements usually found in alloy of this class. The alloy is eminently suited for use as articles in chemical processing apparatus in the manufacture and/or containment of phosphoric acid and sulfuric acid.

Reduction of Phosphate Ores by Carbon: Part I. Process Variables for Design of Rotary Kiln System

Abstract: Feasibility is established for the reduction of phosphate ores in a rotary kiln, avoiding electric submerged arc furnace technology. This represents a totally new approach to phosphoric acid. Reduction rates of phosphate ore-silica mixtures by carbon in the temperature range of 1100 to 1500 °C under several CO partial pressures in nitrogen were measured in thermogravimetric analyzers. Parameters such as carbon and silica contents, particle and pellet sizes, and gas flow rate were also evaluated with various domestic and foreign phosphate ores. Furthermore, a variety of carbon sources such as subbituminous coals, bituminous coals, anthracite, petroleum coke, and metallurgical coke were tested as reducing agents. Thermodynamic considerations elucidate the temperature dependence of overall conversion as well as the role of excess silica in establishing equilibrium pressure. These findings provide the background for analysis of the kinetics of conversion in Part II of this work. These studies, in conjunction with a previously published work, indicate the importance of intergranular melt phases in the kinetics of otherwise solid state reactions.

Fumed silica of controlled aggregate size and processes for manufacturing the same

Abstract: The invention provides fumed silica comprising aggregates that have an aggregate size and a surface area that satisfy particular formulas relating aggregate size to surface area, as well as aggregates that exhibit particular viscosity, power law exponent index, and/or elastic modulus characteristics when dispersed in liquid media. The invention also provides processes of preparing such fumed silica by combining a silica precursor with a stream of combustible gas, combusting the stream, and producing a stream of combusted gas and fumed silica particles, wherein dopants are introduced, the time/temperature profile, or history, of the stream of combusted gas and fumed silica particles is adjusted to allow for post-quench aggregate growth, and/or additional silica precursor is introduced into the stream of combusted gas.

Precipitated silica reinforcing agents and rubber compositions containing same

Abstract: Improved reinforced rubber compositions are provided by dispersion into a vulcanizable rubber of dehydrated precipitated silicas in combination with polyethylenimine.