Naturally occurring carbonates have a wide variation in Mg and Ca contents. Using the density-functional-theory calculations, this study examines the effect of Mg and Ca concentrations on bond lengths and equilibrium fractionation factors of Mg-Ca isotopes among calcite-type carbonate minerals (MgxCa1 xCO3). Mg content x and Ca content (1 x) of the investigated carbonate minerals range from 1/1...

Silicified dolomite of the approximately one billion year old Skillogalee Dolomite of the Adelaide Geosyncline, South Australia, contains organically preserved microfossils of a structurally complex, crustose pleurocapsalean cyanophyte, herein described as Paleopleurocapsa wopfnerii. Although actual cell contents have been degraded, lamellar sheath material faithfully preserves the morphology o...

Li Zhang 1,*, Wu Zhang 2, Juhua Zhang 3 and Guangqiang Li 3 1 School of Materials and Metallurgy, Northeastern University, Shenyang 110819, China 2 School of Materials Science and Engineering, Shenyang Ligong University, Shenyang 110168, China; [email protected] 3 The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China; zhangj...

High-shear and fluid-bed processes were used for granulation of dolomite powder into agrochemical product. In this paper, comparative study of the granulation process focuses on the observation of granule size distribution (GSD). Considerable difference between high-shear and fluid-bed GSDs is analyzed with process kinetics. Simulation of dynamic development of GSD is achieved with application ...

Refractory masonry (refractories) is exposed to in-service loads of different types. To rationalise the design and failure analysis, differences under cyclic monotonic loading were studied. For samples silica refractories tested in wedge splitting set-up global parameters crack trajectories assessed. Under loading, higher fracture energy lower brittleness at seen. Cracks modes had similar non-l...

Nowadays, SiC is one of the refractory materials which is used widespread because of its unique properties like structural stability in high temperatures. SiC nano whiskers are important in reinforcement of different kinds of composites like ceramic base materials, thanks to their outstanding mechanical, thermal, and chemical properties like low expansion coefficient, high thermal resistant, hi...

The oxygen isotopic composition of calcite from carbonate rocks of the lower unit of the Flagstaff formation (Paleocene) exposed along the western margin of the Wasatch Plateau, Utah, is about 7 per mil lower than that of coexisting dolomite, suggesting that isotopic equilibration of these two minerals can occur at relatively low temperatures. Unlike recent isotopic evidence presented by Degens...

Experimental investigations were undertaken in batch kinetic systems, for the removal of iron (II) from aqueous solutions using activated dolomite. The effect of the extent dolomite activation on the dissolution of magnesium and calcium from the dolomite lattice was determined. Under optimum experimental conditions there was a direct linear relationship between magnesium dissolution and iron (I...

The project summarized here investigated some of the parameters and relationships used to predict the performance of limestone contactors. The purpose of the project was to study the effect of limestone composition, especially the dolomite [CaMg(CO 3) 2 ] and impurity content of the stone, on the kinetics of carbonate mineral dissolution and to determine the effect of temperature on the rate of...

Unfavourable soil conditions frequently limit tree regeneration in mountain forests on calcareous bedrock. Rocky, shallow organic soils on dolomite pose a particular problem for tree regeneration due to commonly restricted water and nutrient supplies. Moreover, an often dense layer of understorey vegetation competes for the limited resources available. Hence, an array of interacting factors imp...