Search Results for mineral processing equipment

Structural applications for advanced ceramics include mineral processing equipment, machine tools, wear components, heat exchangers, automotive products, aerospace components, and medical products. This article begins with an overview of the wear-resistant applications and the parameters affecting wear of ceramics, namely, hardness, thermal conductivity, fracture toughness, and corrosion resistance. The next part of the article addresses temperature-resistant applications of advanced ceramics. Specific applications of ceramic materials addressed include cutting tools, pump and valve components, rolling elements and bearings, paper and wire manufacturing, biomedical implants, heat exchangers, adiabatic diesel engines, advanced gas turbines, and aerospace applications.

Ores, which consist of the primary valuable mineral, predominant gangue content, valuable by-products, and detrimental impurities, are extracted and directed to mineral processing. This article describes the mineral processing facilities, such as crushers, grinders, concentrators, separators, and flotation devices that are used for particle size reduction, separation of particles according to their settling rates in fluids and dewatering of concentrate particles. It explains the basic principles, flow diagrams, ore concentrate preparation methods, and equipment of major types of metallurgical processes, including pyrometallurgical, hydrometallurgical, and electrometallurgical processes.

This article focuses on the mineral and organic acid cleaning of iron and steel. It begins with a discussion on the application methods, process selection criteria, solution composition, equipment used, and control of process variables in mineral acid cleaning. The article then describes the advantages and disadvantages of organic acid cleaning. Applications, including boiler cleaning, stainless steel cleaning, and removal of iron- and copper-bearing deposits, are discussed. The article concludes with an overview of acid cleaning of nonferrous alloys.

This article describes the corrosion of principal parts of mining equipment such as mine shafts, wire rope, rock bolts, and pump and piping systems. It discusses the diagnosis and prevention of various types of corrosion including uniform corrosion, pitting corrosion, crevice corrosion, erosion-corrosion, and intergranular corrosion. The article explains the corrosion in tanks, reactor vessels, cyclic loading machinery, and pressure leaching equipment.

This article focuses on the corrosion-wear synergism in aqueous slurry and grinding environments. It describes the effects of environmental factors on corrosive wear and provides information on the impact and three-body abrasive-corrosive wear. The article also discusses the various means for combating corrosive wear, namely, materials selection, surface treatments, and handling-environment modifications.

Tribocorrosion is the subject dealing with complex, synergistic effects of chemical and mechanical conditions that cause wear. This article begins with a discussion on oxidative wear and corrosive wear, as well as quantitative measurements of corrosion, mechanical wear, and wear-corrosion effects. It illustrates the mechanism of corrosive-abrasive wear and discusses the factors affecting two-body wear. These factors include particle shape, size, density, and hardness; slurry velocity; slurry particle angle of attack; solids concentration in the slurry; hydrodynamic factors; corrosion products and the mass transfer of oxygen. The article describes slurry particle impingement tests and grinding tribocorrosion tests, as well as the factors to be considered for mitigating corrosive wear, such as materials selection, surface treatments, and environment modifications.

This article provides a summary of the concepts discussed in the Section “Corrosion in Specific Industries” in the ASM Handbook, Volume 13C:Corrosion: Environments and Industries. This Section applies the fundamental understanding of corrosion and knowledge of materials of construction to practical applications. The industries addressed are nuclear power, fossil and alternative fuel, land transportation, air transportation, microelectronics, chemical processing, pulp and paper, food and beverage, pharmaceutical and medical technology, petroleum and petrochemical, building, and mining and metal processing.

Natural and synthetic rubber linings are used extensively in many industries for their corrosion and/or abrasion resistance. These industries include transportation, chemical processing, water treatment, power, mineral processing, and mining. This article provides information on soft natural rubber, semihard natural rubber, hard natural rubber, neoprene or polychloroprene, chlorobutyl, three-ply linings, nitrile, and ethylene propylene with a diene monomer. Emphasis is placed on advantages, disadvantages, and common uses of each material discussed.

This article describes the methods of wear measurements and a model of corrosive wear in mill atmospheres. It explains the polarization curves of pyrrhotite and high-carbon low-alloy steel in a quartzite slurry with examples. The surfaces of pyrrhotite in contact with mild steel or stainless steel affected by galvanic interaction are discussed. The article contains a table that lists the results of laboratory marked ball wear tests for three types of steel balls in wet grinding of magnetic taconite. It also provides information on the mechanism of electrochemical interaction and relative significance of corrosion and abrasion in wear. Galvanic interactions in multielectrode systems are reviewed. The article presents a case history on the material selection for grinding balls to minimize corrosion loss and the adverse effect on flotation.

This article presents a brief discussion on the main applications for low- and high-viscosity polyalphaolefins (PAOs) and highlights key areas of interest and shows why PAOs are used in these applications. It discusses the physical properties of passenger car motor oils (PCMOs) based on or containing PAOs. The properties include Noack volatility and pour point. The article also discusses the properties and applications of heavy-duty engine oil (HDEO), industrial lubricants, food-grade lubricants, greases, transportation gear oils, compressor oils, hydraulic fluids, and transmission fluids.

This article focuses on lubricants classified as either internal combustion engine or nonengine lubricants, and the lubricant additives. The functional groups of chemically active and inert additives, as well as friction modifiers and other additives, are described in detail. The chemically active additives include dispersants, detergents, antiwear, and extreme-pressure agents, oxidation inhibitors, and rust and corrosion inhibitors. The chemically inert additives include emulsifiers, demulsifiers, pour-point depressants, foam inhibitors, and viscosity improvers. The article also discusses the multifunctional nature of additives and concludes with information on lubricant formulation.

This article describes the eight chemical cleaning methods, namely, circulation, fill and soak, cascade, foam, vapor-phase organic, steam-injected, on-line chemical, and mechanical cleaning. It presents information on deposit types, solvents used to remove them, and construction material incompatibilities in a table. The article summarizes the uses of chemical cleaning solutions, including hydrochloric acid, phosphoric acid, and sulfamic acid, as well as the additives used to neutralize their impact on corrosion. It discusses the chemical cleaning procedures, including selection of cleaning method and solvent, documentation of cleaning, and corrosion monitoring in chemical cleaning.

Wear, a form of surface deterioration, is a factor in a majority of component failures. This article is primarily concerned with abrasive wear mechanisms such as plastic deformation, cutting, and fragmentation which, at their core, stem from a difference in hardness between contacting surfaces. Adhesive wear, the type of wear that occurs between two mutually soluble materials, is also discussed, as is erosive wear, liquid impingement, and cavitation wear. The article also presents a procedure for failure analysis and provides a number of detailed examples, including jaw-type rock crusher wear, electronic circuit board drill wear, grinding plate wear failure analysis, impact wear of disk cutters, and identification of abrasive wear modes in martensitic steels.

Engineered components fail predominantly in four major ways: fracture, corrosion, wear, and undesirable deformation (i.e., distortion). Typical fracture mechanisms feature rapid crack growth by ductile or brittle cracking; more progressive (subcritical) forms involve crack growth by fatigue, creep, or environmentally-assisted cracking. Corrosion and wear are another form of progressive material alteration or removal that can lead to failure or obsolescence. This article primarily covers the topic of abrasive wear failures, covering the general classification of wear. It also discusses methods that may apply to any form of wear mechanism, because it is important to identify all mechanisms or combinations of wear mechanisms during failure analysis. The article concludes by presenting several examples of abrasive wear.

This article discusses the functions and chemistry of metal cutting or grinding fluids. It reviews the choice of cutting or grinding fluids that is influenced by the workpiece material, fluid characteristics, and machining operation. The article describes two application methods of cutting or grinding fluids: flooding and misting. It discusses and lists the American Society for Testing and Materials standard test procedures used in establishing control of cutting and grinding fluids. The article provides information on the storage, distribution, cleaning, and disposal of cutting and grinding fluids. It concludes with information on the health implications and biology of cutting fluids.

Metal surfaces must often be cleaned before subsequent operations to remove unwanted substances such as pigmented drawing compounds, unpigmented oil and grease, chips and cutting fluids, polishing and buffing compounds, rust and scale, and miscellaneous contaminants. The article describes common cleaning processes, including alkaline, electrolytic, solvent, emulsion, molten salt bath, ultrasonic and acid cleaning as well as pickling and abrasive blasting. It also explains how to select the appropriate process for a given soil type and surface composition.

Solvent cleaning is a surface preparation process that can be accomplished in room temperature baths (cold cleaning ) or by condensing vapors of a solvent on a workpiece (vapor degreasing). This article provides a detailed discussion on solvents, equipment, process limitations and applications, and safety and health hazards of cold cleaning and vapor degreasing. It also includes information on control of contamination, conservation and recovery of solvent, and disposal of solvent wastes.

This article provides a brief introduction to abrasive wear-resistant coating materials that contain a large amount of hard phases, such as borides, carbides, or carboborides. It describes some of the commonly used methods of producing thick wear-resistant coatings. The article also provides information on metal-matrix composites and cemented carbides. The three base-alloying concepts, including cobalt-, iron-, and nickel-base alloys used for wear-protection applications, are also described. The article compares the tribomechanical properties of the materials in a qualitative manner, thus allowing a rough materials selection for practitioners. It presents a brief discussion on hot isostatic pressing (HIP) cladding, sinter cladding, and manufacturing of thick wear-resistant coatings by extrusion or ring rolling. The article also discusses the processing sequence of thick wear-resistant coatings, namely, compound casting, deposition welding, and thermal spraying.

This article begins with discussion on forgeability and the factors affecting the forgeability of aluminum and aluminum alloys. It describes the types of forging methods and equipment and reviews critical elements in the overall aluminum forging process: die materials, die design, and die manufacture. The article discusses the critical aspects of various manufacturing elements of aluminum alloy forging, including the preparation of the forging stock, preheating stock, die heating, lubrication, trimming, forming and repair, cleaning, heat treatment, and inspection. It concludes with a discussion on the forging of advanced aluminum materials and aluminum alloy precision forgings.

This article discusses the materials of construction found in pharmaceutical production facilities. The materials discussed are different stainless steels, nickel and nickel-base alloys, titanium, zirconium, impervious graphite, fluoropolymers, and glass-lined steel. The article describes the three primary causes of failure in the manufacture of pharmaceuticals: embedded iron, failures of glass linings, and corrosion under thermal insulation.