Limestone experimental results

Since water is the reactant in equation (1), the diffusion should be important only in removing the products from the reaction zone. The measurements presented in the Experimental Results Section were designed to determine the relative effects of the surface reaction rate and the diffusion of products on the overall dissolution rate. The variables in these tests were temperature, pH, stirring rate, and type of limestone. 

For comparison purposes, the published k values of sand, asphalt, limestone, and sulfur are also given in Table VII. On the basis of the range of values for limestone, the experimental result for asphaltic concrete appears reasonable. 

Thermal Expansion. Experimental results obtained from S—A—S mixtures and a conventional asphaltic concrete are also given in Table VII. Published data on asphalt cement, asphaltic concrete sulfur, sand, and limestone are also provided. The overall thermal expansion coefficient of the composite is derived from the combined effects of the individual ingredients in the mixture and the air voids present in the final material. Any combination which tends to decrease the air voids content... 

An analysis of experimental results on the reaction of SOj with limestone using a grain model similar to the one discussed in this section was published by Pigford and Sliger [15]. 

Porous media can be classified as unconsolidated and consolidated materials. Soils, clays, and packings of various sorts belong to the first class, while rocks such as sandstones and limestones belong to the second. Both classes are investigated in this section. The first two subsections are devoted to ordered or random systems of particles, and the third to a different model of consolidated rocks, based on the classical reconstruction technique [26,34]. Finally, a formula valid in the thick double layer limit is used to gather all the numerical results and also some experimental results found in the literature. 

The experimental results are in general agreement with the theoretical model. The observed effects of chloride concentration on SO2 removal efficiency for a limestone-based... 

Coutanceau-Monteil and Jacquin (1993) investigated the permittivity of sedimentary rock samples in the frequency range from 20 to 1000 MHz. A comparison of model equations and experimental results shows that the GRIM model fits the data for water-saturated quarry limestones, whereas the Hanai-Bruggeman equation fits the data for water-saturated Fontainebleau sandstones fairly well. 

The results of boron determinations in soils by the Spectrophotometric method are shown in Table 12.2. Soil samples were provided by Aula Dei, Experimental Station of the Consejo Superior de Investigaciones Cientificas (CSIC), and correspond to alluvial ground or soils with a high limestone content (35-45% of calcium carbonate). 

In a special publication devoted to sulfide ore dust explosions, a dust explosion in a copper-zinc sulfide mine is discussed and related to causes and preventive measures [1]. Control measures [2] and prevention of secondary explosions are also discussed [3], and surveyed, including the need for further work [4], The results of experimental work on the use of limestone dust to suppress explosions in pyrites dusts are presented [5], For another special publication on ore dust explosion with numerous incidents and further studies on mechanism and control see [6], Explosibility declines in the order pyrrotite, pyrite, chalcopyrite, sphalerite, covellite, chalcocite, galena. Pyrite at 1000 g/m3 can give a peak pressure of 5.8 bar [7], Self heating of broken sulfide ore, to possible ignition, has been studied. Pyrrhotite seems primarily responsible [8],... 

The preparation of quicklime from limestone is C/dC03(s) = CaO(s) + CO2(g). Experiments carried out between 850°C and 950°C led to a set of Kp values fitting an empirically determined (resulting from experimentation) equation... 

This study confirms our previous result [8] that even ultrashort shock experiments with laser and electric discharge guns are well suited to reproduce shock defects known to occur in naturally shocked minerals. For example, dislocation glide and twinning activated in the experimentally shocked specimens have also been detected in weakly shocked limestones from the Ries crater [50]. 

Hanehara and Yamada [360] studied the effect of PA admixture addition on the flow diameter and found an exact lelationship in the case of w/c = 0.4 however the results are not always good for w/c = 0.3 because of the effect of cement with water mixing procedure. This problem was resolved by addition of limestone powder. According to these authors there is no general method of cement-admixture compatibility establishment, but it is possible to settlement certain experimental conditions, which permit to determine it. It is moderate fineness of cement and suitable w/c. Moreover, the proper conformity criteria should be selected, because the plastic viscosity, yield stress value and flow diameter can give various results [400]. In Fig. 6.105 the effect of SP on the relative flow area, chosen as cement-SP compatibility determining parameter, after Yamada [400] is shown. SP does not affect the relative flow area below the threshold value, above this value the flow area is increasing proportionally with admixture, but above the saturation level this parameter is not influenced by an admixture content. 

The results of these experiments showed that the aerosols released from the interaction mixture were primarily composed of elements originating from the concrete materials. Silicon species made up at least 50% of the aerosol mass in the tests with siliceous or limestone/sand concrete in which appropriate amounts of metal had been present. With the exception of tellurium, fission product elements contributed less than about 1% to the total aerosol mass. The release fractions of several low-volatility fission products during the first seven minutes of the tests (in order to compare the different experimental conditions such as type of concrete, type of corium etc.) are shown in Table 7.11. In general, the release fractions of the fission product elements and uranium were about an order of magnitude or more higher for limestone concrete than for siliceous or limestone/sand concretes. These release fractions were greatest when the metal content of the melt was largest, and decreased as metal content decreased and more concrete became incorporated into the melt. 

Deactivation model was later applied by Orbey et al (1982) for the sorption of SO2 with calcined limestone in a packed bed. Values of the deactivation constant was reported both by Dogu and Orbey et al (1981,1982). In a more recent work this approach was extended by Uddin, Orbey and Dogu (1990) by taking both n and m being equal to one in Eq.2.32 and numerical solutions were compared v/ith experimental data. A similar approach was also used by Fan et al (1984) and it was shown that the results are in good agreement with the data in the literature. 

Results are presented for different kinds of analyzed objects. Two macroscopic test objects were manufactured from teflon and PVC with diameters of approximately lO cm Fig. 5 shows the macroscopic objects in different orientations together with the three dimensional reconstruction in corresponding orientations. To verify the method, the volumes of these objects were calculated as well as experimentally determined. The maximum deviation between the two methods was 3 %. Fig. 6 shows the reconstruction of a limestone particle with an equivalent diameter Xp = 90 pm. The reconstructions reveal the typical shape characteristics for this material with a relative smooth surface. 

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