Physical recovery methods

The definition of heavy oil is usually based on API gravity or viscosity, but the definition is quite arbitrary. Although there have been attempts to rationalize the definition based on viscosity, API gravity, and density (2,3), such definitions, based on physical properties, are inadequate, and a more precise definition would involve some reference to the recovery method. 

Micromechanical theories of deformation must be based on physical evidence of shock-induced deformation mechanisms. One of the chapters in this book deals with the difficult problem of recovering specimens from shocked materials to perform material properties studies. At present, shock-recovery methods provide the only proven teclfniques for post-shock examination of deformation mechanisms. The recovery techniques are yielding important information about microscopic deformations that occur on the short time scales (typically 10 -10 s) of the compression process. 

When ores are mineralized in such a way that discrete grains of valuable minerals are contained in a matrix of gangue minerals, physical concentration methods such as flotation, gravity separation, and magnetic separation can yield valuable mineral concentrates with recoveries in the range of 80 to 95% of the value in the ore. However, there are important ore types in which the nature of mineralization is not amenable to physical concentration, and so primary processing by chemical means is necessary. 

REMTL Recovery of metals Recovery of organics uses direct physical removal methods to extract metal or inorganic constituents from a waste... 

Multiobjective optimization is an optimization strategy that overcomes the limits of a singleobjective function to optimize preparative chromatography [45]. In the physical programming method of multiobjective optimization, one can specify desirable, tolerable, or undesirable ranges for each design parameter. Optimum experimental conditions are obtained, for instance, using bi-objective (production rate and recovery yield) and tri-objective (production rate, recovery yield. 

This chapter covers three major approaches to the physical recovery of oil from the water surface, namely skimmers, sorbents, and manual recovery. In many cases, all of these approaches are used in a spill situation. Each method has limitations, depending on the amount of oil spilled, sea and weather conditions, and the geographical location of the spill. 

The recovery of magnetic materials with physical separation methods is principally considered at this time for the following three products HDDs, air-conditioner compressors, and direct drive (DD) motors of laundry machines. In addition, efforts are underway in order to recycle relatively large magnets used in automobiles and industrial machines however, these are excluded from the discussion here because the methods involved do not typically employ mass separation but are rather individual, employing dismantling by hands with only some machine assistance. 

Waste materials such as municipal solid waste, scrap tires, and waste plastics have traditionally been placed in sanitary landfills. However, with landfill space rapidly decreasing in the United States and worldwide, an alternative disposal method for these waste materials becomes imperative. The recycling of solid wastes is a challenging problem, with both economic and environmental constraints. Recently, two broad approaches have been attempted to reclaim solid wastes. The first approach relies on thermal or catalytic conversion of waste materials into fuel and valuable chemical feedstocks. Examples of this approach include gasification, pyrolysis, depolymerization, and liquefaction. The second approach relies on the physical recovery of valuable ingredients in the waste materials. 

Further development of recovery methods contemplated physical and chemical procedures, such as application of pressure, water injection, or implementation of techniques that alter system miscibility. All aspects that impact on the flnal recovery yield must be considered, for example capillary forces oil viscosity contact angle between the adsorbed oil and the solid surface permeability, wettability, and porosity of the solid reservoir among others. Hence, it is obvious that huge perturbations are provoked in the oil reservoirs when surfactant-based systems are used in enhanced oil recovery operations. The potential role of microemulsions in such activities is once again highlighted. 

Control of thermochemical processes under downhole and reservoir conditions is key to both work safety and optimization of enhanced oil recovery methods. In 2010, Emmanuel Institute of Biochemical Physics presented to Rostechnadzor a mobile laboratory that controls reaction under downhole conditions and ensures safe injection of large amoimts of nitrates into the reservoir. Rostechnadzor approved experimental injection of an unrestricted amount of nitrates into boreholes under the requirement of two levels of safety control [5]. 

The treatments used to recover nickel from its sulfide and lateritic ores differ considerably because of the differing physical characteristics of the two ore types. The sulfide ores, in which the nickel, iron, and copper occur in a physical mixture as distinct minerals, are amenable to initial concentration by mechanical methods, eg, flotation (qv) and magnetic separation (see SEPARATION,MAGNETIC). The lateritic ores are not susceptible to these physical processes of beneficiation, and chemical means must be used to extract the nickel. The nickel concentration processes that have been developed are not as effective for the lateritic ores as for the sulfide ores (see also Metallurgy, extractive Minerals recovery and processing). 

Purification. The method used to recover the desired alkylphenol product from the reactor output is highly dependent on the downstream use of the product and the physical properties of the alkylphenol. The downstream uses vary enormously some require no refining of the alkylphenol feedstock others require very high purity materials. Physical property differences affect both the basic type of process used for recovery and the operating conditions used within that process. 

An enrichment is defined as a separation process that results in the increase in concentration of one or mote species in one product stream and the depletion of the same species in the other product stream. Neither high purity not high recovery of any components is achieved. Gas enrichment can be accompHshed with a wide variety of separation methods including, for example, physical absorption, molecular sieve adsorption, equiHbrium adsorption, cryogenic distillation, condensation, and membrane permeation. 

A sharp separation results in two high purity, high recovery product streams. No restrictions ate placed on the mole fractions of the components to be separated. A separation is considered to be sharp if the ratio of flow rates of a key component in the two products is >10. The separation methods that can potentially obtain a sharp separation in a single step ate physical absorption, molecular sieve adsorption, equiHbrium adsorption, and cryogenic distillation. Chemical absorption is often used to achieve sharp separations, but is generally limited to situations in which the components to be removed ate present in low concentrations. 

The special case involving the removal of a low (2—3 mol %) mole fraction impurity at high (>99 mol%) recovery is called purification separation. Purification separation typically results in one product of very high purity. It may or may not be desirable to recover the impurity in the other product. The separation methods appHcable to purification separation include equiUbrium adsorption, molecular sieve adsorption, chemical absorption, and catalytic conversion. Physical absorption is not included in this Hst as this method typically caimot achieve extremely high purities. Table 8 presents a Hst of the gas—vapor separation methods with their corresponding characteristic properties. The considerations for gas—vapor methods are as follows (26—44). 

Separation and Purification of Isomers. 1-Butene and isobutylene caimot be economically separated into pure components by conventional distHlation because they are close boiling isomers (see Table 1 and Eig. 1). 2-Butene can be separated from the other two isomers by simple distHlation. There are four types of separation methods avaHable (/) selective removal of isobutylene by polymeriza tion and separation of 1-butene (2) use of addition reactions with alcohol, acids, or water to selectively produce pure isobutylene and 1-butene (3) selective extraction of isobutylene with a Hquid solvent, usuaHy an acid and (4) physical separation of isobutylene from 1-butene by absorbents. The first two methods take advantage of the reactivity of isobutylene. Eor example, isobutylene reacts about 1000 times faster than 1-butene. Some 1-butene also reacts and gets separated with isobutylene, but recovery of high purity is possible. The choice of a particular method depends on the product slate requirements of the manufacturer. In any case, 2-butene is first separated from the other two isomers by simple distHlation. 

Enzymes are usuaHy sensitive to harsh physical and chemical conditions, and care must be taken during recovery and purification to avoid inactivation of the enzyme. This demands careful selection of production processes and conditions for each individual enzyme. Different methods are subsequently appHed to assure the stabHity and activity of the enzymes during storage and appHcation. 

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