Common Cements

Such cementing compositions are obtained by adding ABS types to common cements used in subterranean applications (85,86). When ABS is added to water-extended slurries, a cementing composition is created with a lower Young s modulus while achieving high compressive and tensile strengths. 

Controlled burning of tires or TDF for fuel value occurs most frequently in tvo types of process units - kilns and boilers. This chapter will describe the general process operation of cement kilns and boilers. The various types of boiler configurations will be described with attention to the implications for burning tires or TDF. Kilns in two industries have burned tires or TDF supplementally - lime manufacturing and, more commonly, cement manufacturing. 

As the name implies, beachrock generally forms in the intertidal to supratidal zone. Magnesian calcite and aragonite are the common cement-forming minerals in... 

In addition, common cement can be attacked by carbon dioxide. Thus all wells though the zone should be completed and, if necessary, abandoned using C02-resistant cement. 

The stability relationships between calcite, dolomite and magnesite depend on the temperature and activity ratio of Mg " /Ca " (Fig. 5d). Lower Mg/Ca activity ratios are required to induce the dolomitization of calcite and to stabilize magnesite at the expense of dolomite (Fig. 5d) (Usdowski, 1994). Formation waters from the Norwegian North Sea reservoirs have an average log(an g -/ cz- ) - TO to 0.0 and thus fall within the stability field of dolomite. Nevertheless, both calcite and dolomite are common cements in these rocks, indicating that dolomitization is a kinetically controlled reaction. Further evidence of this is revealed from Recent sediments, such as the Fraser River delta in Canada (Simpson Hutcheon, 1995) (log (aMg2+/aca=+) -2.2 to h-1.0), where the pore waters are saturated with respect to dolomite, but it is calcite rather than dolomite that precipitates. Calcite rather than dolomite forms below the deep>-sea floor, yet the pore waters plot at shallow, near sea bottom temperatures in the stability field of dolomite and shift with an increase in depth towards the stability field of calcite (Fig. 5d). This shift is due to a diffusion-controlled, downhole decrease in Mg/Ca activity ratio caused by the incorporation of Mg in Mg-silicate that results from the alteration of volcanic material, a process which is coupled with the release of calcium (McDuff Gieskes, 1976). 

The type II calcite is the most common cement in the Namorado Sandstone. It was precipitated relatively early, at an estimated temperature of 25 °C, prior to oil emplacement, whereas type III calcite was precipitated after oil charging in the water zone, at an estimated precipitation temperature of 40°C. 

ENV 197-1 Cement — Composition, specifications and conformity criteria — Common cements , 1993. 

EN 197-1 2000, Cement Part 1 Composition, Spedfications and Conformity for Common Cement, European Committee for Standardization, 2000. 

Sodium jarosite and gypsum are the major species in the commercial Noranda Inc., CEZinc jarofix product. The finer gypsum particles are formed by the reaction of Na-jarosite and cement, whereas the large crystals are from the original gypsum filter cake. Trace amounts of zinc ferrite, hematite and quartz are present in the jarofix product they originate fiom the jarosite residue. Trace amounts of calcium hydroxide which is a cement reaction product, of calcite which forms from the air-carbonation of of Ca(OH)2, and of Ca-Al-Fe oxide ( Ca4Al2Fe08.5 or Ca2(Al,Fe)205) which is a common cement decomposition species are also detected in the jarofix product. 

Angular or rounded grains commonly cemented by clay, calcine or Iron minerals... 

CEN EN 197-1. 2011. Cement - Part 1 Composition, specifications and conformity criteria for common cements. Brussels CEN. 

The cement used for the production of concrete is the common cement (Portland) or cement with fly ash. The cement should be in compliance with national specifications. For Europe and the United States, the relevant specifications for cement are the following CEN EN 197-1 (2011) and CEN EN 450-1 (2012) if with pulverised fuel ash, and CEN EN 197-2... 

The term cemented carbides, also called hardmetals, refers to powder-conqiosite materials consisting of carbide particles bonded with metals or alloys. Extensive treatments are given in [1.94,95]. The most common cemented carbide is WC bonded with Co. Cobalt is used as a binder since it wets the angular WC particles particularly well. Nickel is added to increase corrosion and oxidation resistance of the Co binder phase. The metals Ta, Nb, and Ti may be added to form a (W, Ta, Nb, or Ti) C solid solution carbide phase which is an additional microstructural constituent in the form of rounded particles in the so-called complex grade, multigrade, or steel-cutting grade cemented carbides. Table 3.1-90 lists representative materials. 

This chapter, therefore, describes and compares practical approaches in sample preparation, data collection and data analysis used for quantification and characterisation of (hydrated) cements by XRD. Specific attention is paid to the effects of hydration stoppage and practical strategies towards data collection are described. The aim of the chapter is not only to present best practise but also to inform about compromises inherent in the adopted approaches and to draw attention to potential pitfalls. As an aid to data analysis, a database is given that provides crystal structures and powder diffraction identification files of common cement anhydrous and hydrate phases. Finally, the application of XRD to the study of cements is illustrated by two typical case studies of QPA on (1) an anhydrous portland cement and (2) a hydrated portland cement. 

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