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(chemical engineering)
The concentration of the solids in a suspension in order to recover a fraction with a higher concentration of solids than in the original suspension.
(mining engineering)
Concentrating dilute slime pulp into a pulp containing a smaller percentage of moisture by rejecting the free liquid.



the removal of the liquid phase, for example, water, from disperse systems, for example, pulps, suspensions, and colloids. Thickening forms the basis for the production of condensed milk, fruit and vegetable juices, syrups, and purees. The process consists in the removal of moisture from the starting products in evaporators. After thickening, moisture content in milk and juices is reduced by a factor of 10–15.

As a production operation or, more frequently, an auxiliary operation in production, thickening is used in processes where one stage requires water but subsequent stages require a drastic reduction in the amount of water. Processes of this type include the production of paper, the concentration of ores, and processes in hydromechanization and hydrometallurgy. In the production of paper, the ground fibrous mass is mixed with water, thereby forming a suspension. After stirring and the removal of mechanical impurities, the suspension is subjected to thickening prior to shipment to the factory. In wet concentration of ores, a pulp is formed, which consists of a concentrate and 40–60 percent water. Since the water content in the concentrate shipped to the factory should not exceed 5–15 percent, the pulp is first thickened, which reduces the water content by a factor of 1.5–2, and then dehydrated, which results in an almost total removal of water. When dredges are used to work gravel deposits containing sand, the content of the material in the pulp is 3–6 percent by volume. Prior to screening and hydraulic separation, the sand in the pulp is thickened to a concentration of 10–15 percent.


References in periodicals archive ?
Computerized tomography of the chest revealed bilateral, multi-focal large pleural thickenings and also pleural thickening of the right major fissure appearing as a mass in the parenchyma (Figure 2).
Drug-induced pulmonary diseases due to beta-blockers have been published previously as pulmonary parenchymal infiltration and pleurisy, but bilateral multifocal and extensive pleural thickening alone has not been mentioned previously.
We report herein a case in which treatment with acebutolol was followed by bilateral extensive pleural thickening necessitating withdrawal of the drug.
However bilateral, multi-focal and extensive pleural thickening due to beta-blockers has not been reported previously.
Additionally pleural biopsy excluded mesothelioma and pleural thickening secondary to asbestos exposure.
In our case, however, there were no pulmonary symptoms since the patient had bilateral pleural thickening without effusion or lung infiltration.
Researchers next found the characteristic skin thickenings and spherical fungal bodies in dying leopard frogs in Arizona (SN: 7/4/98, p.