gypsiferous soils occur in xeric, ustic, and aridic moisture regimes. environmental conditions affect the mode of gypsum formation. gypsiferous soils in fars province, southern iran, are found in piedmont plains, flood plains, and alluvial plains. the objective of this work was to investigate the micromorphology of gypsum crystals formed under different soil moisture regimes. the results indica...

Late Quaternary soils in southern New Mexico support previous work that suggested pedogenic gypsum accumulates in successive stages as a function of time, similar to pedogenic carbonate. However, gypsum also occurs as small (0·5}1 mm), powdery spheres that we term snowball morphology. The snowball morphology represents one of the initial stages of pedogenic gypsum development. Scanning electron...

The potential for mineral scaling that may limit the generation of new potable water resources by reverse osmosis (RO), from inland brackish water of high gypsum scaling propensity, was experimentally explored via flux decline measurements and real-time RO membrane surface imaging. Antagonistic gypsum and calcium carbonate scaling kinetics were demonstrated for high-sulfate brackish water desal...

Surface crystallization of calcium sulfate dihydrate (gypsum) on a series of polymeric surfaces was studied using a quartz microbalance system. Polyelectrolyte multilayer films (positively and negatively charged surfaces) were formed on the quartz crystal microbalance (QCM) sensors utilizing a layer-by-layer spin-assembly method. The kinetics of gypsum surface crystallization was quantified in ...

This work identifies unknown crystals found encrusting the Marcellus Shale Formation at the Mapleton Quarry locality in Central Pennsylvania, over the course of a month. The outcrop has been exposed for sufficient time for there to be advanced chemical weathering, allowing for the presence of secondary minerals to form and changes in the composition of the surrounding water table and environmen...

With the enlarging of industrial desulfurization, the amount of FGD gypsum is increasing rapidly. The preparation of alpha-calcium sulfate hemihydrate (α-HH) is one of the biggest concerns for FGD gypsum reclamation. The influence of mixed chlorate solution of Mg-Ca-Na concentrations (5-30 wt%) and FGD gypsum concentrations(5-30 wt%) by hydrothermal salt solution method at atmospheric were inve...

Mineralogical processes taking place close to equilibrium, or with very slow kinetics, are difficult to quantify precisely. The determination of ultraslow dissolution/precipitation rates would reveal characteristic timing associated with these processes that are important at geological scale. We have designed an advanced high-resolution white-beam phase-shift interferometry microscope to measur...

Wet flue gas desulphurization (FGD) plants with forced oxidation, installed at coal and oil fired power plants for removal of SO2(g), must produce gypsum of high quality. However, quality issues such as an excessive moisture content, due to poor gypsum dewatering properties, may occur from time to time. In this work, the particle size distribution, morphology, and filtration rate of wet FGD gyp...