Refractories are commercial products created from nonmetallic minerals that possess the capacity to maintain their form and strength when subjected to highly elevated temperatures amid varying extremes of mechanical stress and chemical attack by hot gases, liquids, or molten and semi-molten substances. In the modern economies of the world, alumina (Al2O3), the oxide of aluminum, … Read more

Canada is a producer of natural refractory minerals, electrofused minerals, and synthetic refractory minerals. Several deposits also have good potential for development. During the past two years three new graphite mines have been developed. The mines produce flake type graphite and they have a combined production capacity of about 55,000-60,000 t/y of concentrates that grade … Read more

The management of solid waste is an ever increasing concern in the United States. Every year our nation generates between 140 to 160 million tons (Lichstein, 1990 and Thayer, 1989) of municipal solid waste. Only about 10 pct of the waste is recycled, mostly aluminum and paper. About 135 million tons of this waste end … Read more

Pigments are used in two segments of paper making, as the major component in paper coating formulations and, in small percentages, as fillers in the paper web. Historically, the dominant use has been in coating, however, recent developments have fostered a multifaceted effort to substantially increase the pigment component in the paper furnish. Factors responsible … Read more

Kaolin is a white, naturally occurring, hydrated aluminum silicate that is formed by the weathering of feldspar. Commercially significant deposits of paper grade kaolin are located in Georgia and South Carolina in the southeast United States, the Cornwall District of England, Brazil, and Australia. Kaolin deposits are classified as primary or secondary deposits depending on … Read more

Although paint is often considered to be a relatively simple commodity, it is in fact a complex composite material. Considerable effort is required to design a coating which is easily manufactured, applies easily by a variety of techniques, dries evenly, covers thoroughly, has a pleasing appearance, resists physical or chemical attack, and is cost efficient. … Read more

Serpentinite minerals are available in large quantities from asbestos mining activity. The granular or fibrous serpentite, at temperatures greater than 700°C, will recrystalize into olivine, forsterite and enstatite. These minerals have been used and studied for decades and are environmentally safe. The thermal process changes the composition and properties of the original mineral. Therefore, the … Read more

Although calcium sulfate dihydrate, commonly referred to as gypsum, has been utilized for some time in fiberglass reinforced polyester (FRP) applications, it does not have the fire retardant filler recognition of ATH. Gypsum is more commonly known for application in cement, soil and water treatment, plaster, and wall-board. Inherent characteristics of gypsum limit its use … Read more

Acid-activated clays are produced almost exclusively from southern or nonswelling bentonites by treatment with various mineral acids. When used for their ability to decolorize or “bleach” color pigments from vegetable and petroleum oils, they are called bleaching clays or bleaching earths. Although sometimes confused with fuller’s earths, which are also sometimes called bleaching clays (Table … Read more

Key Properties and Tests of Absorbent Clays: Clay deposits in the ground contain from 30-40% water. This leads to the remarkable observation that a thick clay bed that can support heavy machinery is by volume 50% water. Most clays when they dry shrink noticeably. Wyoming bentonite, for example, develops a “popcorn-like” appearance on drying owing to … Read more