[1] Multiproxy data from ODP Hole 1017E (Point Conception, California) provide an excellent opportunity to examine the behavior of barium, within a well‐characterized sedimentary system. Bariumexcess is generally considered to be a productivity proxy; however, in nearshore environments, Baexcess records can be compromised by both sediment provenance and barite remobilization. For the last 60 ky...

Abstract: the reduction agent. Pellets of barite ore containing about 95% BaSOtemperature, time, ore grain size and the type and grain size of the carbon materials. Graphite, coke and charcoal havebeen used as the reducing agent and the reduction experiments have been performed in the temperature range of 925-1150 °C. Apart from conducting the experiments using pellets made of ore powder, kinet...

Most commercial water contains alkaline earth metal cations such as magnesium, calcium and barium, and anions such as carbonate, bicarbonate, sulfate, silicate, oxalate, phosphate, etc. Different combinations of these anions and cations will give rise to potentially scalant systems, such as calcium carbonate, calcium silicate, calcium sulfate, calcium oxalate, barium sulfate, magnesium sulfate,...

Barite particles with a rich variety of well-defined morphologies have been synthesized by using double-hydrophilic block copolymers (which consist of a hydrophilic solvating block and a hydrophilic binding block) as crystal growth modifiers to direct the controlled precipitation of barium sulfate from aqueous solution. The influences of variation in functional group and molecular structure of ...

Barite plaster has been largely used as shielding material in installations housing gamma radiation sources as well as x-ray generating equipment, in order to minimize exposure to individuals. However, some physical characteristics, such as density, plasticity, resistance to compression and radiation attenuation for the different types of barite plaster commercially available in Brazil are not ...

Deposits of barium sulfate are a common issue in the oil and gas industry. The presence these crystals impacts production, causing technical problems such as inhibiting flow rate, increasing pressure pipe, pipe to break be damaged. results this study show formation (BaSO4) with batch crystallizer method at 300 °C under influence stirring rotation speed (0 rpm, 120 240 360 480 rpm) additive conc...

The desmid green alga Closterium moniliferum belongs to a small number of organisms that form barite (BaSO(4)) or celestite (SrSO(4)) biominerals. The ability to sequester Sr in the presence of an excess of Ca is of considerable interest for the remediation of (90)Sr from the environment and nuclear waste. While most cells dynamically regulate the concentration of the second messenger Ca(2+) in...

In this study fuzzy arithmetic is presented as a tool to tackle the prediction of the amount of barium, strontium and calcium sulfates scales in oilfield operations. Since the shape of fuzzy numbers’ membership functions is a spread representative of the whole possible values for a special model parameter, fuzzy numbers are able to consider the uncertainties in parameter determinations and thus...

Microbial processes played a major role in mineral precipitation throughout the Earth’s history. Such processes have been widely discussed for the last few decades with regard to carbonate precipitation. Other than microbial precipitation of carbonates, in natural environments is also of great interest the potential role of microbes in the precipitation of marine barite. Regarding carbonates, o...

The sulfur isotope composition of pyrite in marine sedimentary rocks is often difficult to interpret due a lack precise isotopic constraints for coeval sulfate. This study examines and barite the Late Devonian Canol Formation (Selwyn Basin, Canada), which provides an archive δ 34 S 18 O values during diagenesis. Scanning electron microscopy (SEM) has been combined with microscale secondary ion ...