Ceramic digestion methods

Mann S., Geilenberg D., Broekaert J. A. C. and Jansen M. (1997) Digestion methods for advanced ceramic materials and subsequent determination of silicon and boron by inductively coupled plasma atomic emission spectrometry, J Anal At Spectrom 12 975-979. 

Inductively coupled plasma-mass spectrometry (ICP-MS) has been utilized as a bulk technique for the analysis of obsidian, chert and ceramic compositional analyses 12-14). However, due to the high level of spatial variation of ceramic materials, increased sample preparation is necessary with volatile acids coupled with microwave digestion (MD-ICP-MS) to properly represent the variability of ceramic assemblages IS, 16). Due to the increased sample preparation and exposure to volatile chemicals, researchers have continued to utilize neutron activation analysis (INAA) as the preferred method of chemical characterization of archaeological ceramics (77). 

Typically, these will be alloys, rocks, fertilisers, ceramics, etc. These materials are taken into solution using suitable aqueous/acid media, according to solubility hot water, dilute acid, acid mixtures, concentrated acids, prolonged acid digestion using hydrofluoric acid if necessary, alkali fusion (e.g. using lithium metaborate), Teflon bomb dissolution. Fusion and bomb methods are usually reserved for complex siliceous materials, traditionally reluctant to yield to solubilisation. 

Microwave-assisted digestion has been applied to other types of samples such as ceramics [198,199], air particulate matter [200-202], polymers [203,204], lithographic materials [205], coal and ash [206], among others. As with the previous samples, the main purpose was the determination of their metal contents. The results provided by microwave-assisted digestion are similar to those obtained with conventional methods. 

Bauxitland Cement. See kuhl cement. Bayer Process. A process for the extraction of alumina from bauxite, invented by K. J. Bayer in 1888. The bauxite is digested with hot NaOH and the AI2O3 is then extracted as the soluble aluminate. Because of this method of extraction, the calcined alumina used in the ceramic industry usually contains small quantities of Na20. 

The duration of all studies was 5 million cycles conducted at a frequency of 1 Hz using 25% v/v bovine serum as a lubricant, which was replaced every 333,000 cycles. Wear was determined gravametrically for metal and ceramic materials and geometrically for UHMWPE every million cycles. Wear surfaces were analysed with a 3D form Talysurf and wear debris analysed using digestion, centrifugation and SEM/TEM. Analysis methods have been extensively reported in a previous publication [4]. All components were 28 mm in diameter and commercially available. 

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