Wet Abrasive Conditions

In the South African mining industry most processes for recovering precious metals, coal, minerals and diamonds are wet methods, involving the suspension of solids in water [1], In the control of such wet abrasive conditions in the pumping of fine particles size slurries, particle size separation in cyclones and in floatation cells, the choice of soft natural rubber lining is the most cost effective. 

The wet track abrasion test covers measurement of the wearing qualities of slurry seal under wet abrasion conditions. 

Cross-linked finishes are not permanent in the tme sense of the word however, under optimum conditions the finish can last for the usehil life of the material. Wet abrasion during laundering is probably the principal cause of gradual removal of the finish. In order to retain antistatic protection for extended use, an excess of finish is often appHed The extent of chemical interaction between the durable antistatic agents and the fiber substrates to which they are appHed is not perfectiy understood. Certain oxidizing agents such as hypochlorite bleaches tend to depolymerize and remove some durable antistatic finishes. Some of the durable finishes have also produced undesirable side effects on textile materials, ie, harsh hand, discoloration, and loss of tensile properties. 

Often several different robotic transport systems are used to convey the wafers to and from locations inside the CMP tool. Most tools have two basic internal environments under which they must operate (1) a wet environment of multiple spray rinses, moist atmospheres, and high particle (slurry abrasive) conditions, and (2) a dry environment with an ultraclean low-particle... 

The determination of wearing is carried out according to CEN EN 12274-5 (2003). The test method determines the minimum binder content of the mix under wet track abrasion conditions. It also covers the compatibility between aggregate fillers and cationic bitumen emulsion. The test is similar to wet track abrasion loss described in ASTM D 3910 (2011), a brief description of which is given in Section 6.8.3.1. 

Silica can be added as extender to increase wet abrasion resistance. Small amounts of aluminium oxide can also be used instead of silica with little effect on sheen. Because of the abrasive nature of aluminium oxide, it should be added at the end of the let down stage with just sufficient stirring for good wetting and dispersing. Pine oil may be used as plasticiser for improved odour characteristics. Epoxy ester emulsions, such as Araldite DP-624 (Ciba), may be added to improve resistance to cracking and lifting of the film under severe exterior conditions. 

To remain safe and efficacious on the eye, contact lenses must maintain clear and wetted surfaces, provide an adequate supply of atmospheric oxygen to and adequate expulsion of carbon dioxide from the cornea, allow adequate flow of the eye s tear fluid, and avoid excessive abrasion of the ocular surface or eyeflds, all under a variety of environmental conditions. The clinical performance of a contact lens is controlled by the nature of the lens material the lens design the method and quaUty of manufacture the lens parameters or specifications prescribed by the practitioner and the cleaning, disinfection, and wearing procedures used by the patient. 

Different rubber compounds are used in the manufacture of floatation cell rubber components for various corrosion and abrasion duty conditions. Floatation as applied to mineral processing is a process of concentration of finely divided ores in which the valuable and worthless minerals are completely separated from each other. Concentration takes place from the adhesion of some types of solids to air bubbles and wetting of the... 

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