Abstract. Barite formation is of concern for many utilisations the geological subsurface, ranging from oil and gas extraction to geothermal reservoirs. It also acts as a scavenger mineral retention radium within nuclear waste repositories. The impact its precipitation on flow properties has been shown vary by orders magnitude, emphasising need robust prediction models. An experimental flow-thro...

BACKGROUND In geochemically perturbed systems where porewater and mineral assemblages are unequilibrated the processes of mineral precipitation and dissolution may change important transport properties such as porosity and pore diffusion coefficients. These reactions might alter the sealing capabilities of the rock by complete pore-scale precipitation (cementation) of the system or by opening n...

This paper studies several kinetic aspects of flotation of celestite and calcite in a mechanical cell with sodium dodecylsulphate as the collector agent, using pure minerals ranging in average particle size between 137 and 74 mm, respectively, with a constant pH 3 in the flotation bath in all experiments. The results obtained indicate that both minerals float rapidly and that the flotation rate...

Skeletal biomineralisation by microbial eukaryotes significantly affects the global biogeochemical cycles of carbon, silicon and calcium. Non-skeletal biomineralisation by eukaryotic cells, with precipitates retained within the cell interior, can duplicate some of the functions of skeletal minerals, e.g. increased cell density, but not the mechanical and antibiophage functions of extracellular ...

Synechococcus strain GL24 is a unicellular cyanobacterium that was isolated from Fayetteville Green Lake, New York, a meromictic lake which has high Ca and SO(4) concentrations. Epicellular mineralization of Synechococcus cells in the lake is the mechanism by which extensive calcitic bioherms (or microbial reefs) have been formed on the lake's shore and a marl sediment has been built on the lak...

Celestite/barite−replaced and phosphate−replicated tubes of Early Cambrian anabaritids from the northern part of the Si− berian Platform (Anabar Shield) give new evidence on the wall−structure of these enigmatic fossils. The walls consist of fibres, interpreted as reflecting an original aragonitic fabric. Bundles of fibres are arranged in growth lamellae, and the latter form an angle of at leas...