Melting minerals, carbon content

Resistance to environmental stress cracking - Measurement of the melt flow index -Carbon black and/or mineral filler content measurement in polyethy-lene by direct combustion - Measurement of carbon black content by thermogravimetric analysis (TGA) - Assessment of carbon black dispersion in polyethylene using a microscope... 

Figure 2.24 is a plot of fluidity (measured as dial divisions per minute (ddpm) of the Gieseler equipment) against the carbon content of the coal (wt% diy mineral matter free basis (dmmf)). Considerations of fluidity are a matter of considerable importance in activated carbon production. A coal which fuses (melts), such as a bituminous coal, on carbonization requires a different pre-treatment from a coal which does not melt (brown coals and anthracites). 

The conventional approach to asphalt analysis has been to extract the bitumen with an organic solvent and then to characterize bitumen and minerals separately. Sulfur content and melting point are commonly measured properties of bitumen. Minerals are generally screened and then subjected to simple quantitative tests. Measurement of weight loss on ignition helps to distinguish between calcium carbonate, which loses... 

The total aluminium content is obtained in order to characterize the soil with respect to the soil-forming substrate, weathering, etc. Together with analyses of other components of clay minerals, it may be used for calculating values which may be employed in the identification of clay minerals. To obtain the aluminium solution, the sample is melted with sodium carbonate and the melt is dissolved in concentrated hydrochloric acid. 

Fillers are mainly used for reasons of economy, but in many cases they also improve some properties of the polymer. The most important fillers for polymers are minerals such as talc, chalk and china clay. Filler content generally used with plastics is up to 60 wt%. The most common practice is to feed the filler downstream into the melt by means of a twin-screw side feeder (Figure 6.3). It is well-known that thermoplastic melts with high loadings of small particles such as calcium carbonate, carbon black and titanium dioxide give both yield values in shear flow [58, 59], and uniaxial extension [60, 61]. 

The use of lithium in glass and ceramics applications is continuing to expand throughout the world because of the increased durability it imparts to the glass or ceramic product. Some glass and ceramics manufacturers use lithium carbonate, but lithium minerals are preferred because of the additional alumina and silica contained in the mineral product. Petalite is particularly desirable because of its very low iron content Addition of lithium lowers melting points and reduces the coefficient of... 

---