Solid/liquid separation stages

Vinification has consistently been reported to reduce ochratoxin A concentrations in wine, independent of the initial ochratoxin A concentration in grapes. Ochratoxin A is removed at each solid-liquid separation stage of the process. 

Solid/liquid separation is important at all stages and depends on the extent of coal cleaning during pretreatment, depolymerization of coal macromolecules at the dissolution stage, and catalyst durability through the catalytic process. 

A. Interface of Primary and Secondary Stages—Solid/Liquid Separations... 

Solid/liquid separation is usually required at the interface of the primary and secondary stages to allow optional upgrading of the crude coal liquids of the primary liquefaction stage, by removing mineral matter, unreacted coal, heavy products, and catalysts (111, 112). Distillation, anti-solvent extraction, and centrifugation have been conventionally employed in liquefaction processes (113, 114). 

The recovery of valuable minerals and metals requires several stages of sequential processing operations. The mined ore must be crushed and ground to fine sizes prior to treatment by such bene-ficiation processes as heavy-medium separation, tabling, magnetic separation, electrostatic separation, flotation, selective flocculation, etc. Since most of these processes are carried out in aqueous media, solid-liquid separations by such operations as thickening and filtration are an integral part of the benefici-... 

Solid-liquid separation systems generally consist of four stages, which are 1) pretreatment to increase particle size 2) solid concentration in thickeners 3) solid separation in filters and centrifuges and 4) posttreatment to remove solubles and reduce liquid content. Fig. 6 shows the relationship among these stages. 

Fig. 8 Equipment used for the four stages of solid-liquid separation.

Solid-liquid separation systems generally consist of four stages including pretreatment, solid concentration in thickeners, solid separation in filters or centrifuges, and post-treatment by expression and washing operations. There are different types of SLS equipment served for different functions in relation to the four stages. Product specification, characteristics of solid-liquid suspension, solid settling velocity, rate of cake... 

Svarovsky, Ladislav. 1990. Solid-liquid separation. 3rd ed. London, Boston Butterworth Co., 29-30. Tiller, F.M. 1978. Characteristics of staged, delayed-cake filters. Filtration and Separation May/June XXX. Tiller, F.M. 1974. Continuous processes for cake filtration. Chemical Engineering April 29. 

As shown in Fig. 11.1-1, the solids—liquid separation device is the link between the solids formation equipment and the diying operation, Thus, predictable and reliable operation is essential in this stage of the processing sequence. Continuous or baich-automatic centrifuges nad continuous vacuum filters are typically used to recover solid material from continuous crystal I ization operations. Many factors are considered in [ha final selection of the device. In any case, an equipment testing program is always essential to determine the capacity and performance of solids separation equipment. 

Fig. 1 a-c Biphasic solid/liquid separations of a soluble polymer a beginning with a biphasic mixture of reactants and polymeric catalyst but with an intermediate monophasic reaction mixture and a biphasic solid/liquid separation b beginning with a monophasic mixture of reactants and polymeric catalyst, with an intermediate monophasic reaction mixture but with formation of a biphasic mixture of polymer and products that is separated or c beginning with a biphasic mixture of reactants and polymeric catalyst that remains biphasic throughout the reaction and through the separation stage... 

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