Diatomite fillers

Similar deposits of radiolaria or diatoms composed of siUceous skeletal remains are widespread in more temperate areas in deep water below 5000 m. The deposits maybe very pure. The diatoms recovered from deposits on land are used as fillers or filter materials or as a source of high quaUty carbonate or sihca (see Diatomite). 

There are two principal ways in which finished diatomite products are used in manufacturing plants either as a filter aid (see Filtration), where the diatomite is expendable, or as a filler, where the diatomite becomes a component and remains as part of the manufactured product. As of 1990, the use of diatomite products was 71% filtration, 15% fillers, and 14% other (7). 

Typically, a filter cake or precoat is built up on the filter septa to prevent blinding, short filter cycle times, and cosdy cleaning of the septa. Then diatomite is added as body feed to the Hquid to be filtered so that the permeabiHty of the filter cake may be maintained. Filler aid permeabiHty of diatomite ranges from 0.06 to 30 lnF. At the end of the filter cycle the filtrate is clear and the soHds are retained in the soHd or semisoHd diatomite filter cake. The type and amount of diatomite for precoat and body feed are normally deterrnined by pilot studies (18,19). 

Fillers. Diatomite mineral fillers are used primarily (/) where bulk is needed with minimum weight increase, (2) as an extender where economy of more expensive ingredients is a factor, or (3) where the stmcture of the particle is important. In other appHcations, diatomite can add strength, toughness, and resistance to abrasion, or it can act as a mild abrasive and polishing agent (see Abrasives). 

Diatoms are single-celled algae that produce a hard skeleton made of hydrous silica (opal). The rock that forms from consolidated layers of diatom skeletons is called diatomite. This material has many common and commercial names, including diatomaceous earth, Fuller s earth, kieselgur, and tripo-lite. Diatomite is mined and used as building material, in filters, as insulation, as a mild abrasive, and as a filler in dry chemicals. 

For hundreds of years sticky surfaces have been dusted with powder (e.g., talc) to keep them separated. Talc is broadly used in cable and profile extrusion to obtain a smooth surface. Similarly, in injection molding, the application of aluminum trihydroxide gives a better surface finish. Talc, CaCOs, and diatomite provide anti-blocking properties. Graphite and other fillers decrease the coefficient of friction of materials. PTFE, graphite and M0S2 allow the production of self-lubricating parts. Here, PTFE, a polymer in powder form, acts as a filler in other polymers. Matte surfaced paint is obtained by the addition of silica fillers. 

Dicalite Natural Diatomite Functional Fillers 104, CA-3, lG-3, 143, SA-3,182 Dicalite Processed Diatomite Functional Fillers WF, WFAB, 395, WB-5, L-5, L-10, SP-5, PS, SF-5 World Minerals, Inc., Celite, Lompoc, CA, USA... 

Figure 2.24 shows the method of processing of diatomite to different grades of fillers. The natural grades are uncalcinated powders which are crushed and classified according to particle size distribution. In this process moisture is also removed. Natural diatomite contains 40% moisture. In the production of the calcinated and the flux-calcinated products, large kilns are used. The high... 

Kenite. [Witco] Diatomite filter aid, anticddng t ents, absmbent bulking agent condition , extmider pigment filler, opacifier. 

Diatomite (Kieselguhr). Diatomaceous earth (as it is also called) is chemically ineit, but it has high adsorptive power. This can account for adsorption of curing ingredients that interfere with accelerated-sulfur vulcanization. However, diatomite is used as a filler in silicone rubber. Because of its high adsorptive capacity, it is used as a process aid in high-oU rubber compounds. 

Diatomite di- a-t9- mlt (1887) (diatomaceous earth, DE, kieselguhr, infusorial earth, siliceous earth, and tripolite) n. The naturally occurring deposit of skeletons of small unicellular algae called diatoms, consisting of from 83 to 89% silica. Its many uses include fillers for plastics. 

Dicalite diatomite, perlite functional fillers Redland... 

Oicalite Diatomite functional fillers are produced from dlatonaceous earth, a versatile and valuable raw material. 

Natural diatomite - This is diatomite ore which has been gently crushed and milled to retain the finstule shape and then screened and air classified to remove impurities and to segregate products into coarse finctions for filtration applications and fine tractions for filler uses. 

Annual worldwide production of diatomite is approximately 1.6 million metric tons, dominated by the United States with about 37% of this total. Other major producers are France, the former Soviet republics, and Spain. Production in Romania and the former Soviet repubhcs is almost exclusively of relatively low-value material for construction products. Uses elsewhere are dominated by filtration applications (80% in the US, 60% worldwide). The only other major use is as a filler. 

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