bluuebunny/crossref_metadata_2025 huggingface dataset:
Drying
Authors: McCormick Paul Y.
Published: August 2004

Drying is an operation in which volatile liquids are separated from solids, slurries, and solutions to yield solid products. Drying mechanisms and processes, including psychometry, heat‐ and mass‐transfer principles, and a description of liquid and vapor flow encountered during drying are discussed. In freeze drying (lyophilization), wet material is cooled to freeze the liquid and vaporization occurs by sublimation.

Industrial dryers may be broadly classified according to the method of heat transfer as being either direct‐heat or indirect‐heat dryers. The types of dryers employed in the chemical industry, which may also be classified as batch or continuous, are described. Conventional, radiant, dielectric, and microwave heat sources are discussed as are emission control and energy usage of the various dryer types.
Drying Oils
Authors: Wicks Zeno W.
Published: August 2004

Natural and synthetic drying oils are discussed. Occurrence, isolation, composition, and analysis of oils is covered. Mechanism of drying through free‐radical initiated autoxidation is described with particular emphasis, in the case of oils with nonconjugated double bonds, of the role of activated methylene groups between double bonds. The reactions are catalyzed by oil‐soluble transition‐metal salts. Modified and synthetic oils include: varnishes, synthetically conjugated oils, esters of higher functionality polyols, maleic anhydride‐modified oils, and vinyl‐modified oils. Data on economic aspects and lists of specifications are included. Natural drying and semidrying oils as well as their fatty acids are used in making alkyds, epoxy esters, and urethane oils, which can properly be considered synthetic drying oils. Uses of drying oils discussed include paints, printing inks, and other uses.
Electroseparations, Electrophoresis
Authors: Rudge Scott , Markey Kathleen
Published: August 2004

Electrophoresis is a separation technique which is most often applied to the analysis of biological and other polymeric samples. The principles, modes of operation, separation matrices, detection techniques, and equipment for the various electrophoresis techniques are presented. The three principal modes of electrophoresis, zone electrophoresis, isoelectric focusing, and isotachophoresis, are discussed, as are the advantages of the principal matrices in which electrophoresis is performed, including agarose, polyacrylamide, paper, capillaries, and flowing buffers. Specific examples of techniques such as immunochemical reaction, two‐dimensional techniques, and blotting are given.
Electroanalytical Techniques
Authors: Sandifer James R.
Published: August 2004

Electroanalytical techniques may be classified as involving active or passive measurements. Active measurements, such as those obtained in coulometry and voltammetry, result from the application of a voltage or current. Passive measurements, such as those from an ion‐selective electrode, are made independently of external waveforms. The various electroanalytical techniques are described, as is the assembly of electrochemical cells for electroanalysis. Electroanalytical cells employ at least two electrodes placed in either aqueous or organic media. Analyte concentrations may be in the picomolar to molar range. Electroanalytical systems may be employed independently or in conjunction with a separation technique such as chromatography.
Embedding
Authors: Wong C. P. , Xu Jianwen
Published: August 2004

Advances in electronic technology have had great technological and economic impact on the electronic industry throughout the world. The rapid growth of the number of components per chip, the rapid decrease of device dimension, and the steady increase in IC chip size have imposed stringent requirements not only on IC physical design and fabrication, but also in electronic packaging and embedding. Electronic embedding is one of the most common processes used to encapsulate and protect electronic components. With advances in VLSI technology and multichip modules packaging, embedding of high density packages in electronics has become a challenge. Various polymeric encapsulants are used for embedding these types of electronic components. These materials, such as silicones, silicon‐carbon thermosets, epoxies, polyurethanes, polyesters, polysulfides, and advanced thermoplastics, and their electrical, mechanical, and rheological properties as well as material processes related to molding, potting, casting, and saturation coating processes, are discussed in detail. Furthermore the studies of material curing by differential calorimetry, ftir, and microdielectrometry are described.

The development of a novel aluminum‐filled high dielectric composite is detached. Aluminum is a fast self‐passivation and low‐cost metal. The thin passivation layer forms a boundary layer outside of metallic spheres that has dramatic effects on the electrical, mechanical, and chemical behaviors of the resulting composites.
Ethylene Oxide
Authors: Dever J. P. , George K. F. , Hoffman W. C. , Soo H.
Published: August 2004

Ethylene oxide is a colorless gas that condenses at low temperatures into a liquid and is miscible with water and most organic solvents. Its vapors are flammable and explosive. Ethylene oxide can be relatively toxic as both a liquid or gas, and is considered as a potential human carcinogen and reproductive hazard.

Ethylene oxide was first prepared from ethylene chlorohydrin and aqueous potassium hydroxide in 1859. It was first produced commercially during World War I in Germany by the chlorohydrin process. In 1931, direct oxidation of ethylene to ethylene oxide was achieved by using a silver catalyst. The chlorohydrin process was quickly replaced by the direct oxidation process, and is still the dominate technology.

Ethylene oxide is a highly reactive compound; it is used industrially as an intermediate for many chemical products. The total world production capacity in 1992 was about 9.6 × 106metric tons. More than 98% of the total ethylene oxide production is converted to derivatives. About 60–65% is consumed in the manufacture of ethylene glycol. Other derivatives include glycol ethers, ethanolamines, and surfactants. The fastest growing market is expected to be ethylene glycol for polyester production.
Ethylene–Acrylic Elastomers
Authors: Dobel Theresa M.
Published: August 2004

Ethylene‐acrylate elastomers are a family of addition copolymers of ethylene and methyl acrylate that were commercialized under the trademark VAMAC by Du Pont Co. in 1975. Traditional grades of ethylene‐acrylic elastomers also have small amounts of a carboxylic monomer polymerized into the polymer backbone to provide cure sites for cross‐linking with amines. A line of copolymers of only ethlyene and methyl acrylate has been added to the ethylene‐acrylic family. In this article cure properties, aging characteristics, mechanical properties, and low temperature properties of ethylene‐acrylic elastomers are reviewed. Special compounded attributes such as uniquely temperature‐stable vibrational damping properties and the ability to produce flame‐resistant and smoke suppressive compounds are also discussed. Ethylene‐acrylic elastomers are processed in the same manner as other elastomers. Because of this balance of properties, ethylene‐acrylic elastomers have found ready acceptance in many high performance applications, especially in the automotive market.
Fermentation
Authors: Sengha Surjit S.
Published: August 2004

Fermentation uses microorganisms to manufacture products such as alcoholic beverages, antibiotics, enzymes, organic acids, amino acids, vitamins, and other materials. The processes may be either anaerobic or aerobic. Fermentation is often the only financially viable method for manufacturing complex molecules such as enantiomers. There are over 150 companies worldwide employing bacteria, yeast, and fungi in fermentation processes which consist of preparing sterile medium, fermentors, and related equipment; propagation of seed cultures; culturing the microorganisms; separation of the product from the fermentation broth; and subsequent purification. Fermentations, which typically require oxygen, carbon, and nitrogen sources and other nutrients such as raw materials, are computer controlled to provide optimal pH, temperature, oxygen saturation, and nutrient concentrations.
Fertilizers
Authors: Taylor Alan W.
Published: August 2004

The function of fertilizer applications is to raise the level of soil fertility and biological activity in the soils and farming areas where they are used by increasing the amounts of available plant nutrients, in particular, nitrogen and phosphorus. As a result, adverse environmental impacts may occur to water quality. In recent years, there has been a large body of research directed toward the need to reduce the fertilizer contribution to these problems.
Fillers
Authors: Falcone James S.
Published: August 2004

Fillers are finely divided solids added to paints, paper, plastics, and rubber to modify the mechanical and optical properties of the system. They also reduce the usage of generally more costly matrix materials, eg, wood pulp, polymer resins, or paint vehicles.
Catalyst Regeneration, FCC units
Authors: Upson L. L. , Lomas D. A.
Published: August 2004

The fluid catalytic cracking (FCC) process is an important refinery process in the United States. Catalyst regeneration is an essential part of this process. In the reactor section of a FCC unit, hydrocarbon feed is combined with hot fluidizable cracking catalyst at the base of the riser reactor. Catalyst and hydrocarbon vapors pass up the riser in a dilute‐phase, plug‐type flow and discharge into the reactor vessel where catalyst and hydrocarbon vapors are separated. When in contact with the catalyst, the hydrocarbon feed cracks to form gasoline, middle distillates, liquefied petroleum gas (LPG), and fuel gas. Coke, which is also formed, deposits on the catalyst surface and greatly reduces the catalyst activity. To restore its activity, the catalyst passes into the regenerator section where the coke is burned off. The heat released from coke burning is completely used to provide the heat requirements on the reactor side. Heat balance, environmental concerns, regenerator configuration and design, and other parameters of FCC are discussed.
Formaldehyde
Authors: Gerberich H. Robert , Seaman George C.
Published: August 2004

Formaldehyde is a versatile, reactive substance, basic to the chemical industry because of its low cost and ease of production. It is manufactured by vapor‐phase oxidation of methanol using two principal processes. One method employs a pure silver catalyst and the other an iron molybdate catalyst. Several other processes are under development, but none have been commercialized. All processes are capital intensive, requiring integrated reaction, heat recovery, and purification systems to achieve optimum economic benefits.

Formaldehyde is sold as concentrated, aqueous solutions, and may contain methanol to inhibit polymerization. It is also sold in alcohol solutions, which contain little water. Its principal uses are in the production of amino and phenolic resins, polyhydric alcohols, acetal resins, paraformaldehyde, and fertilizers. It reacts with numerous organic compounds in condensation‐type reactions, resulting in formation of one or more new carbon‐carbon bonds.

In recent years, formaldehyde has come under increased scrutiny because of its potential negative health effects. It is an irritant to the eyes, nose, and throat, and is a suspected human carcinogen.
Initiators, Free‐Radical
Authors: Sanchez José , Myers Terry N.
Published: August 2004

Most commercial free‐radical applications employ initiators such as peroxides and azo compounds. Lesser amounts of carbon–carbon initiators and photoinitiators, and high energy ionizing radiation are also used commercially to generate free radicals. The chemical initiators are substances possessing labile oxygen–oxygen, carbon–nitrogen, or carbon–carbon covalent bonds that under certain thermal, chemical, or photochemical conditions undergo homolytic scission of the labile bond to produce free radicals. The free radicals produced are useful in many industrial chain reactions, eg, halogenations, additions to carbon–carbon double bonds, polymerizations of vinyl monomers, grafting reactions, curing of rubbers and unsaturated polymers, cross‐linking of polyolefins, modification of polyolefins, and reactive processing.

In this article free‐radical initiator decomposition pathways are reviewed. Initiator reactivity is related to chemical structure and to first‐order decomposition parameters such as temperature, frequency factor, and activation energy. Reactivity of derived free radicals is also related to structure and to the occurrence of secondary reactions such as β‐scission and induced decomposition. The energy and the chemical properties of the free radicals determine commercial utility, thus the interrelation of initiators, their kinetics, and the radicals produced provide guidelines for initiator selection.
Furnaces, Fuel‐Fired
Authors: Bozzuto Carl R.
Published: August 2004

A furnace is a device (enclosure) for generating controlled heat with the objective of performing work. In fossil‐fuel furnaces, the work application may be direct (eg, rotary kilns) or indirect (eg, plants for electric power generation). The furnace chamber is either cooled (waterwall enclosure) or not cooled (refractory lining). Furnaces related to metallurgy such as blast furnaces are excluded. Fuel‐fired furnaces primarily utilize carbonaceous or hydrocarbon fuels. Since the purpose of a furnace is to generate heat for some useful application, flame temperature and heat transfer are important aspects of furnace design. Industrial furnaces are an order of magnitude smaller than power‐plant furnaces since the applications are usually on an individual basis rather than feeding power to a regional electric grid. Like the power‐plant furnace, the function of the industrial furnace usually is to generate steam, generally for a chemical process, mechanical power, or heating application, rather than electric power generation. New furnace concepts in evolutionary stages include fluidized‐bed furnaces, coal gasification furnaces, and MHD furnaces. Fluidized‐bed combustion has reached commercial‐scale operations.
Germanium and Germanium Compounds
Authors: Thomas Dennis W.
Published: August 2004

Germanium is a semiconducting metalloid element found in Group 14 (IVA), Period 4 of the Periodic Table. Although it looks like a metal, it has a diamond cubic crystal structure and is fragile like glass. Its electrical resistivity is about midway between that of metallic conductors and good electrical insulators. The first significant use was in solid‐state electronics, and, using germanium, the transistor was invented. The entire modern field of semiconductors owes it development to the early successful use of germanium. Germanium is used for optical fiber production, as polymerization catalysts, in infrared optics, in electronic and solar applications, and in other miscellaneous markets. Germanium usually occurs widely dispersed in minerals. Most germanium production has been from zinc smelters and copper smelters.

Germanium also occurs in significant concentrations in many coals around the world. Germanium is quite stable in air up to 400°C, where slow oxidation begins. The metal resists concentrated acid and alkali. Many Ge alloys have been prepared and studied.

No mineral is mined solely for its germanium content. Almost all of the Ge recovered worldwide is a by‐product of other mining. Germanium compounds generally have a low order of toxicity.
Glass
Authors: Boyd David C. , Danielson Paul S. , Thompson David A.
Published: August 2004

Both organic and inorganic materials may form glasses if their structure is noncrystalline, ie, if they lack long‐range order. This includes some plastics, metals, and organic liquids. In principle, rapid cooling could prevent crystallization of any substance if the final temperature is sufficiently low to prevent structural rearrangement. Thus glasses are formed primarily for kinetic reasons.

Glasses can be prepared by methods other than cooling from a liquid state, including solution evaporation, sintering of gels, reaction sputtering, vapor deposition, neutron bombardment, and shock‐wave vitrification.

Conditions favorable for glass formation may be deduced from either geometric or bond strength considerations. Glass formation of individual oxides can be predicted from the melting point, and individual bond energies can be normalized by dividing by the melting point of the oxide. Glass is a good medium for controlled crystallization, and has become the basis for a number of unique crystalline materials known as glass‐ceramics.

Most glass articles are manufactured by a process in which raw materials are converted at high temperatures to a homogeneous melt that is then formed into the articles. Molten glass is either molded, drawn, rolled, or quenched, depending on desired shape and use.

In a secondary forming, a piece of preformed glass is reheated and reworked into the finished product. Glass manufacture is classified according to the product into flat, container, fiber, or specialty glass.

Glasses are used in the electrical and electronic industries as insulators, lamp envelopes, cathode ray tubes, and encapsulators and protectors for microcircuit components. The resistance of glass to chemical corrosion $$$ frequently the reason for its use. However, the durability of a glas varies from highly soluble to highly durable, depending on its composition and the solvent considered. Optical glasses are usually described in terms of their refractive index.
Hafnium and Hafnium Compounds
Authors: Nielsen Ralph H.
Published: August 2004

Hafnium, Hf, is in Group 4 (IVB) of the Periodic Table, as are the lighter elements zirconium and titanium. Hafnium is a heavy gray‐white metallic element never found free in nature. It is always found associated with the more plentiful zirconium. The two elements are almost identical in chemical behavior.

Hafnium is obtained as a by‐product of the production of hafnium‐free nuclear‐grade zirconium. Hafnium's primary use is as a minor strengthening agent in high temperature nickel‐base superalloys. Additionally, hafnium is used as a neutron‐absorber material, primarily in the form of control rods in nuclear reactors.

Hafnium is a hard, heavy, somewhat ductile metal having an appearance slightly darker than that of stainless steel. Hafnium's aqueous chemistry is characterized by a high degree of hydrolysis, the formation of polymeric species, a very slow approach to true equilibrium, and the multitude of complex ions that can be formed. Hafnium is a highly reactive metal.

Most hafnium compounds have been of slight commercial interest aside from intermediates in the production of hafnium metal. However, hafnium oxide, hafnium carbide, and hafnium nitride are quite refractory and have received considerable study as the most refractory compounds of the Group 4 (IVB) elements.
Fluorine Compounds, Inorganic, Halogens
Authors: Bailey Webb I. , Woytek Andrew J.
Published: August 2004

There are eight known halogen fluorides, binary compounds of fluorine with chlorine, bromine, and iodine. The halogen fluorides are highly reactive, powerful oxidizing agents that exist as noncryogenic liquids, offering a storable liquid source of fluorine at low pressure. Properties are described.

Chlorine trifluoride, bromine trifluoride, and iodine pentafluoride are available commercially. Chlorine trifluoride is used in the processing of nuclear fuels, bromine trifluoride as a chemical cutting agent for oil well pipe and tubing, and iodine pentafluoride as a fluorinating agent for organic compounds.
Hydrogen
Authors: Czuppon T. A. , Knez S. A. , Newsome D. S.
Published: August 2004

Hydrogen is one of the most important industrial commodities. Physical thermodynamic, and chemical properties are described. The chemistry of hydrogen from a commercial perspective is followed by a description of manufacturing methods. Steam reforming of hydrocarbons and partial oxidiation of hydrocarbons account for almost all hydrogen production. Other, less conventional manufacturing methods are also presented, such as hydrogen from coal, water splitting by electrolysis and chemical means, solar processes, metal–water reactions, bacteria, nuclear, and hydrogen sulfide‐splitting reactions. Hydrogen purification is reviewed. The storage of hydrogen is discussed, including conventional methods for gas and liquid storage, and possible future methods, such as in metal hydride systems and microcapsules. Analysis of hydrogen, health and safety issues, and environmental considerations are discussed. Hydrogen consumption figures are presented, and the possible future usage of hydrogen is discussed.
Hydrogen Peroxide
Authors: Hess Wayne T.
Published: August 2004

Hydrogen peroxide is a strong oxidizing agent commercially available in aqueous solution over a wide concentration range. Its many uses involve its varied chemistry and are based on oxidations, reductions, substitutions, molecular additions, and decompositions. Product from hydrogen peroxide decomposition are the environmentally benign oxygen and water. Manufacture and use, especially in industrial bleaching applications, are on the rise, fueled by environmental concerns and ecological pressure to replace chlorine‐based bleaching with the cleaner peroxide chemistry.

Manufactured primarily in large, strategically located anthrahydroquinone autoxidation processes, the primary use for hydrogen peroxide is in bleaching wood pulp. Hydrogen peroxide is also produced electrolytically. The various manufacturing processes are discussed. Safe use and handling require adherence to approved procedures and use of proper protective equipment.
Indium and Indium Compounds
Authors: Slattery James A.
Published: August 2004

Indium, indium alloys, and indium compounds exhibit a wide range of diverse properties. For example, the metal retains plasticity at cryogenic temperatures and many compounds with the metalloids are semiconducting. Applications vary from the use of the metal in the control rods of nuclear reactors, to that of alloys as solders, and of indium trioxide as an electrically conductive film for glass and plastic.

Indium is basically a by‐product of the zinc and lead–zinc industries. Properties are described. Uses and production are discussed.
Enzyme Applications, Industrial
Authors: Kirk Ole , Damhus Ture , Borchert Torben Vedel , Fuglsang Claus Crone , Olsen Hans Sejr , Hansen Tomas Tage , Lund Henrik , Schiff Hans Erik , Nielsen Lone Kierstein
Published: August 2004

Enzyme technology has been used in industrial applications since ancient Greece. The present industrial applications of enzymes are, however, the result of a rapid development seen primarily over the past four decades thanks, first of all, to the evolution of modern biotechnology. The result is a highly diversified market that is still growing both in terms of size and complexity.

The detergent industry is the largest user of industrial enzymes. Enzymes such as proteases, amylases, lipases, and cellulases are used to remove soilings, increase softness, and protect fabric. The starch industry uses a variety of enzymes, first of all of amylases, in the production of value‐added products from starches. Enzymes also find use in the textile, leather, pulp and paper, and animal feed industries. Another important area is the food industry in which enzymes are used in the dairy, bakery, brewing, and protein modification industries.

The introduction of protein engineering and directed evolution has revolutionized the development of industrial enzymes and made it possible to tailor‐make enzymes to display new activities and adapt to new process conditions enabling a further expansion of their use. Production of enzymes involves recombinant expression in selected host microorganisms, fermentation, recovery, and formulation.
Inks
Authors: Bassemir R. W. , Bean A.
Published: August 2004

This article includes a description of the important commercial printing processes used in the world. The inks required for each of these processes are described, including the key ingredients in the formula necessary due to the physical constraints of each particular printing process. A discussion of the nature of the raw materials used in printing inks and their general chemical composition is given. A summary of the environmental regulations applying to the printing industry and their impact on ink formulation is presented.
Aluminum Compounds, Introduction
Authors: Sleppy William C.
Published: August 2004

The CAS registry lists 5037 aluminum‐containing compounds exclusive of alloys and intermetallics. The aluminum containing compound having the largest worldwide market is metal‐grade alumina. Second is aluminum hydroxide. The split between additive and feedstock applications for Al(OH)
3
is roughly 50:50. Additive applications include those as flame retardants in products such as carpets, and to enhance the properties of paper, plastic, polymer, and rubber products. Significant quantities are also used in pharmaceuticals, cosmetics, adhesives, polishes, dentifrices, and glass. Aluminum sulfate,

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, also known as alum cake, is industrially produced for major applications as a sizing agent in the paper industry and as a coagulant to clarify municipal and industrial water supplies. In terms of worldwide production, it ranks third behind alumina and aluminum hydroxide. All the halogens form covalent aluminum compounds having the formula AlX
3
. The most important commercially are the anhydrous chloride and fluoride, and aluminum chloride hexahydrate. The latter is used in pharmaceuticals and cosmetics as a flocculant and for impregnating textiles. The alkyls and aryls, R
3
Al (in monomer form), are colorless liquids or low melting solids easily oxidized and hydrolyzed when exposed to the atmosphere. Triethylaluminum (TEA), one of the most commercially important members of this family of chemicals, is so reactive it bursts into flame on contact with air, ie, it is pyrophoric, and it reacts violently with water. Special techniques are necessary for the safe handling and use of organoaluminum compounds, which are used commercially in multimillion kg/yr quantities as catalysts or starting materials for the manufacture of organic compounds such as plastics, elastomers biodegradable detergents, and organometallics containing zinc, phosphorus, or tin. Sodium aluminate is used in water purification, in the paper industry, for the after‐treatment of TiO
2
pigment, and in the manufacture of aluminum‐containing catalysts and zeolite. A large and growing industrial use of aluminum hydroxide and sodium aluminate is the manufacture of synthetic zeolite. Zeolites are aluminosilicates with Si/Al ratios between 1 and infinity. There are 40 natural, and over 100 synthetic, zeolites. Zeolite‐based materials are extremely versatile: uses include detergent manufacture, ion‐exchange resins (ie, water softeners), catalytic applications in the petroleum industry, separation processes, and as an adsorbent for water, carbon dioxide, mercaptans, and hydrogen sulfide.
Ketones
Authors: Braithwaite John
Published: August 2004

Braithwaite, John (Union Carbide Chemicals and Plastics Co., Inc.). Ketones are a class of organic compounds that contain one or more carbonyl groups bound to two aliphatic, aromatic, or alicyclic substituents. Ketones are an important class of industrial chemicals that have found widespread use as solvents and chemical intermediates. Acetone is the simplest and most important ketone and finds ubiquitous use as a solvent. Higher members of the aliphatic methyl ketone series (eg, methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone) are also industrially significant solvents. Cyclohexanone is the most important cyclic ketone and is primarily used in the manufacture of γ‐caprolactam for nylon‐6. Other ketones find application in fields as diverse as fragrance formulation and metals extraction. Physical and chemical properties as well as uses, manufacture, and health and safety data are given.
Lanthanides
Authors: Sabot Jean‐Louis , Maestro Patrick
Published: August 2004

Maestro, Patrick, and Sabot, Jean—Louis (Rhône‐Poulenc Inc.). Lanthanides is the name given collectively to the 15 elements from lanthanum to lutetium sharing the same space in Mendeleev's original Periodic Table. Lanthanides have a unique electronic structure because of partially filled 4forbitals. Occurrence and preparation of the rare earths is described. Mining of lanthanide ores and the various separation methods are discussed. Except for cerium and europium, the lanthanides are separated industrially of solvent extraction. The production of lanthanide metals is also presented.

Industrial applications of lanthanides encompass a number of different fields, including the high technology field of electronics. Uses in metallurgy, catalysis, and the glass and ceramics industry are based on unique chemical and structure properties. Uses as luminescent materials for phosphor applications or in medical imaging technology are limited to specific optical properties. Uses of lanthanides and their alloys as high energy magnets result from the special magnetic properties. Information storage is but one of many industries in which lanthanide usage is expected to grow. Vol. 14, pp. 1091–1116, 51 refs. to January 1993.
Lime and Limestone
Authors: Gutschick K. A.
Published: August 2004

Lime and limestone are mainstays of the construction industry, in chemical and metallurgical production, and for other industrial and agricultural uses. In the United States limestone production comprises about 75% of total stone output. Lime is produced from high purity limestone.

The geological, physical, and chemical properties of lime and limestone are described as well as steps in production and primary uses. Whereas limestone is primarily a construction material used especially in road building, it is also used in the production of pig iron, glass, cement, and lime, as a scrubbing agent for removal of SO
2
from stack gases, as a mineral filler, etc. Lime is primarily a chemical and metallurgical raw material, used in the production of steel, gold and copper, aluminum, calcium carbide, pulp and paper, etc. It is also a leading material in environmental uses, such as SO
2
removal from power plant stack gases, in potable and wastewater treatment, and for hazardous wastes. Lime is also an important construction material, used in masonry mortar, plaster, and stucco, in road building to stabilize highly plastic clays, and in manufacture of calcium silicate building products such as sand–lime brick. Growth is expected in scrubbing stack gases, in the production of precipitated calcium carbonate for use as a filler in fine white paper, and for sterilizing sewage sludge for cropland use.
Amines, Lower Aliphatic Amines
Authors: Turcotte Michael G. , Johnson Thomas A.
Published: August 2004

Lower aliphatic amines are derivatives of ammonia with one, two, or all three of the hydrogen atoms replaced by alkyl groups of five carbons or less. Amines with higher alkyl groups are known as fatty amines. Amines are toxic, colorless gases or liquids, highly flammable, and have strong odors. Lower mol wt amines are water soluble and are sold as aqueous solutions and in pure form. Amines react with water and acids to form alkylammonium compounds analogous to ammonia. The base strengths in water of the primary, secondary, and tertiary amines and ammonia are essentially the same. The lower aliphatic amines are widely used as intermediates in the manufacture of medicinal, agricultural, textile, rubber, and plastic chemicals. Some commercially important alkylamines are methylamine, dimethylamine, ethylamine,
n
‐propylamine, isopropylamine, allylamine,
n
‐butylamine, isobutylamine,
sec
‐butylamine, ethyl‐
n
‐butylamine,
n
‐amylamine. The formation of salts with acids is the most characteristic reaction of amines. Alkylamine are corrosive to copper, copper‐containing alloys (brass), aluminum, zinc, zinc alloy, and galvanized surfaces. Lower aliphatic amines can be prepared by a variety of methods, using many different types of raw materials. By far the largest commercial applications involve the reaction of alcohol with ammonia to form the corresponding amines. Other methods are employed depending on the particular amine desired, raw material availability, and plant economics. The U. S. Department of Transportation requires labeling of all shipments of amines commensurate with the associated hazards. Alkylamines are toxic. Both the liquids and vapors can cause severe irritation to mucous membranes, eyes, and skin. Protective butyl rubber gloves, aprons, chemical face shields, and self‐contained breathing apparatus should be used by all personnel handling alkylamines.
Magnesium Compounds
Authors: Kramer Deborah A.
Published: August 2004

A variety of magnesium compounds and minerals are found both in seawater and in the earth's crust. Commercial magnesium compounds are widely used in chemical processing, whether in the production of paper or rayon fiber, or as a catalyst, filler, flame retardant, alkaline material, stable coating for magnetic recording media, or wastewater or flue gas scrubber. Magnesium hydroxide is a common over‐the‐counter antacid and laxative. Additionally, the branch of synthetic organic chemistry known as Grignard reactions is based on magnesium compounds. Magnesium forms stable salts with most common anions, such as acetate, carbonate, the halides, hydroxide, oxide, and sulfide, as well as with some less common ones such as vanadates. Many magnesium alkyls are also known. The production, properties, economics, uses, safe handling, and analysis of the commercial magnesium compounds are described.
Magnesium and Magnesium Alloys
Authors: Wilson Clifford B. , Claus Ken G. , Earlam Matthew R. , Hillis James E.
Published: August 2004

Magnesium is the world's most readily available metal and occurs naturally in minerals, brines, and seawater. Magnesium metal is prepared commercially by two types of processes. In the first process, magnesium chloride is recovered from the raw materials and converted to metal by molten salt electrolysis. The second process involves the reduction of magnesium oxide with silicon or aluminum at high temperatures. The resulting metal is then cast into a variety of shapes and sizes of ingots, or alloyed with various other metals and made into ingots, slabs, billets, and many extruded shapes. Pure magnesium is used for making aluminum alloys, the desulfurization of steel, the manufacture of ductile iron, and as a reducing agent for the production of other metals. Elemental magnesium is the lightest structural metal. Magnesium alloys are used mainly in die and sand castings, and in the manufacture of wrought products. Alloy composition is varied to obtain the desired physical and mechanical properties for a given application.
Metal‐Matrix Composites
Authors: Chawla K. K.
Published: August 2004

(New Mexico Institute of Mining and Technology). Metal‐matrix composites have a metal or an alloy as the continuous phase, in which the reinforcing phase (particle whisker, short or continuous fiber) is distributed. Important techniques for processing metal‐matrix composites are described. A description of the reinforcement/matrix interface region and its characteristics, and properties of different metal‐matrix composites are provided. Different applications of metal‐matrix composites are summarized.
Methacrylic Acid and Derivatives
Authors: Gross Andrew W. , Dobson John C.
Published: August 2004

Methacrylic acid, the simplest branchedα,β‐unsaturated carboxylic acid, and its ester derivatives have found wide use in polymer chemistry. Although primarily utilized in radical polymerizations, these materials also undergo a variety of reactions typical ofα,β‐unsaturated carbonyl compounds. The primary method of manufacture is via the conversion of acetone cyanohydrin to methacrylamide sulfate and subsequent hydrolysis to methacrylic acid. Alternative syntheses include routes starting from ethylene, propylene, methylacetylene, and isobutylene. Key intermediates include isobutyraldehyde and methacrolein. Market and price data are presented. Handling procedures and toxicological studies are reviewed.
Methyl Chloride
Authors: Holbrook Michael T.
Published: August 2004

Methyl chloride is the simplest chlorinated hydrocarbon and occurs naturally in significant quantities. At ordinary temperatures and pressures it is a colorless gas with a very mild odor and a sweet taste. The principal methods of industrial preparation are methanol hydrochlorination and methane chlorination. U.S. capacity has been estimated at 339,000 t/yr. Its primary use is in the production of silicone rubbers and as a general methylating agent. Growth rates of 1–2% per year have been made for the early 1990s. Methyl chloride is regulated by a number of federal and state laws.
Catalyst Regeneration, Metal Catalysts
Authors: Robinson D. W.
Published: August 2004

The regeneration of deactivated heterogeneous noble metal catalysts, such as promoted platinum‐alumina reforming catalyst, can be successfully achieved by the removal of carbonaceous deposits from the catalyst surface using a carefully controlled combustion procedure followed by platinum redispersion and rechloriding of the catalyst support. Three regeneration techniques are in common commercial practice for noble metal catalysts. The continuous catalyst regeneration system used in the CCR Platforming process continuously circulates spherical catalyst between the regeneration vessel and the process reactors. The regeneration methods used for fixed catalyst‐bed reforming processes are also discussed. Regeneration of non‐noble or base metal catalysts such as those used in hydrocracking processes can also successfully restore catalyst performance to near that of fresh catalyst. Catalysts containing base metal hydrogenation components, such as nickel, cobalt, molybdenum, and tungsten, and an acidic support, such as alumina, silica‐alumina, or zeolites, are used in a variety of refining processes. If catalyst deactivation in this service is a result of carbonaceous deposits, the catalytic performance can be substantially improved by a regenerative oxidation treatment to remove this deposit. Theex situregeneration is performed in moving‐bed belt calciners or conical‐shaped rotating drum calciners.
Fibers, Olefin
Authors: Wust, Jr. C. J.
Published: August 2004

Olefin fibers, also known as polyolefin fibers, are synthetic fibers of growing commercial importance. Several olefin polymers are capable of forming fibers, but only polypropylene and polyethylene are of practical importance. From the first commercial application of polyethylene in automobile seat covers to multicomponent extrusion for specialty applications, olefin fibers have made a significant impact in the fiber industry. This article reviews the fiber properties, including physical, tensile, chemical, and thermal and ultraviolet stability, which make them ideally suited for these varied applications. Commercial fiber manufacturing and processing is discussed for staple fiber, continuous filament, and directly formed nonwovens. The extrusion, quench, and draw play integral roles in the development of the fiber properties. Bicomponent, high strength, and hard‐elastic fiber technology is examined.
Chloroethanes
Authors: Snedecor Gayle
Published: August 2004

The physical and chemical properties, manufacturing methods, uses, environmental concerns, and toxicity of the following chloroethanes are discussed: 1,1‐dichloroethane, 1,2‐dichloroethane, 1,1,1‐ trichloroethane, 1,1,2‐trichloroethane, 1,1,1,2‐tetrachloroethane, 1,1,2,2‐tetrachloroethane, pentachloroethane, and hexachloroethane.
Flame Retardants, Overview
Authors: Gann Richard G.
Published: August 2004

Fires result from an ignition source meeting a flammable product. Fire or flame retardants are commonly added to polymeric products to slow or prevent ignition and to reduce the intensity of burning should ignition occur. This article provides an introduction to fire retardants. It presents reasons why fire retardants are useful, general mechanisms for their effectiveness, how the performance of polymer‐retardant composites is measured, a summary of the market for these chemicals, and forces that might change that market.
Phosgene
Authors: Dunlap Kenneth L.
Published: August 2004

Phosgene is a colorless, low boiling liquid which is manufactured by reaction of carbon monoxide and chlorine over activated carbon. It is a very toxic substance, and extensive safety procedures and equipment have been developed to help ensure the safe handling of phosgene. Phosgene is an important and widely used intermediate for chemical synthesis. Its primary use is for the manufacture of polyisocyanates for the polyurethane industry. Other uses are the production of polycarbonate, chloroformates, agrochemicals, and intermediates for pharmaceuticals and dyestuffs. Vol. 18, pp. 645–655, 91 refs. to August 1995.
Flame Retardants, Phosphorus
Authors: Weil Edward D.
Published: August 2004

One of the principal classes of flame retardants for plastics and textiles is that of phosphorus, phosphorus‐nitrogen, and phosphorus‐halogen compounds. These flame retardants are also used for wood and paper. The mechanisms of action, which may be in the condensed or vapor phase or in both, are presented. The interactions with other flame retardants are discussed.

Commercial phosphorus‐based flame retardants include some inorganic compounds as well as both additive and reactive organic phosphorus systems. These materials range from simple salts to oligomeric compounds and encompass both liquids and solids. Some commercial products are pure compounds. Others are mixtures. The various compounds, corresponding structures, and specific uses are given. The toxicity of these products is discussed.
Chromogenic Materials, Piezochromic
Authors: Drickamer H. G.
Published: August 2004

In its most general sense piezochromism is the change in color of a solid under compression. There are three aspects of the phenomenon: (1) the color of a solid results from the absorption of light in selected regions of the visible spectrum by excitation of an electron from the ground electronic state to a higher level. If the two electronic energy levels are perturbed differently by pressure, compression results in a color change. This is the basic definition of pressure tuning spectroscopy; (2) a discontinuous change of color occurs when a crystalline solid undergoes a first‐order phase transition from one crystal structure to another; (3) the phenomenon of most interest is a change in color of a solid as a result of a change in the molecular geometry of the molecules that make up the solid. Examples of material's piezochromic behavior and the types of transitions involved are discussed.
Plastics Testing
Authors: Furches Barbara J.
Published: August 2004

Plastics testing covers analytical, thermal, physical, and environmental procedures for determining the composition, structure, as well as mechanical and other responses to a variety of environmental conditions of plastic materials. General uses of Fourier transform infrared, nuclear magnetic resonance, Raman, and x‐ray techniques are reviewed and illustrated with specific examples. Developments in neutron and x‐ray scattering techniques, as well as molecular weight determination techniques such as gel‐permeation chromatography and turbidimetric methods, are also covered. Thermal tests, thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry, and dynamic mechanical analysis are all useful for understanding degradation and phase changes in polymers and their influence on material behavior. Several mechanical testing techniques are used in plastics for normal quality control testing and initial application screening of polymers. These tests and those used for more fundamental understanding of polymer response to stress, including fracture mechanics procedures, are referenced. Flammability tests commonly used for plastics include oxygen index, flammability ratings, and smoke generation. Work on the use of cone calorimeters to characterize behavior of plastics under fire conditions is also covered. Finally, environmental testing, chemical exposure, weathering, radiation, and biological agents are reviewed. Emphasis is given to test development or applications reported since 1980.
Plastics Processing
Authors: Xanthos M. , Todd D. B.
Published: August 2004

Processing of plastics comprises a variety of operations involving flow and shaping of polymer melts into finished articles. For thermoplastic resins the most common processing operations are extrusion and molding. In extrusion, solid plastic resin is melted and then shaped in a continuous part of a defined cross section by screw‐conveying and forcing the melt to flow through a die. Die forming is used in pipe and tubing, film, sheet, wire, and cable coating. Molding involves such noncontinuous processes as injection molding, blow molding, rotational molding, and compression molding, in which three‐dimensional parts are made in a closed mold. Molded products are solid, hollow, or foamed. Other thermoplastics operations include thermoforming, calendering, and casting. In contrast to thermoplastics, thermosetting resins use low viscosity components which, through chemical reaction, produce the solid part in the mold. Common processing methods for thermoset systems are compression molding, transfer molding, and injection molding. Specialized techniques developed for fiber‐reinforced thermosets include open‐mold processing, pultrusion, resin transfer molding, and reaction injection molding. Specific processing methods for making low density articles from thermoset polyurethanes are described.
Fine Chemicals
Authors: Pollak Peter , Habegger Erich
Published: August 2004

Fine chemicals are low volume, high priced chemical intermediates and bulk active ingredients primarily used in the preparation of pharmaceuticals and agrochemicals, but are also used in other specialties, such as household and personal care ingredients, electronic chemicals, and flavors and fragrances. In contrast to specialty chemicals, these intermediates are sold within the chemical industry and according to specifications rather than performance criteria. Fine chemicals typically are manufactured by batch processes in multipurpose plants starting from commodity chemicals and involving several distinct chemical or biotechnological steps. A typical fine chemical plant consists of a “wet” section, where the chemical reactions and the preliminary solid–liquid separations are carried out, and a “dry” section, where the product drying, milling, sieving, and packaging takes place. The wet section is further divided into production trains that allow individual process steps to be performed. The main apparatus are jacketed and agitated 1–10‐m3reaction vessels connected to overhead condensers, and filters resp. centrifuges. The smallest production unit is a “train”. A train consists usually of three jacketed reactors with overhead condensers, head tanks, receivers, and a filtration unit (centrifuge or nutsche). Several trains are regrouped in a production building. A complete plant also comprises an administrative building, R&D, and analytical laboratories, a pilot plant, utilities, maintenance and waste disposal units, and a warehouse.