Amelioration of subsoil acidity using gypsum (CaS04.2Hz0) or lime (CaC03) was studied on sandy textured soils with low water holding capacity in a low rainfall environment. Field trials were established in 1989 at two sites on yellow sandplain soils to investigate whether different rates, sources and combinations of gypsum and lime application could be used to increase wheat and lupin yields. G...

With the huge explored reserves of potash salts in Kazakhstan, there is still no production fertilizers, demand for which constantly growing. In this regard, research processing largest Chelkar deposit ore into fertilizers and an urgent problem. The article presents results washed decomposition with nitric acid suspension filtration. filtering properties granulometric composition insoluble resi...

The hydrogeochemical evolution of Bosten Lake has an important impact on the lake’s ecology and water environment. Kriging interpolation, principal component analysis Piper Gibbs charts were used to analyze hydrochemical characteristics genesis in summer autumn. following are main conclusions: (1) In autumn, hydrochemistry lake follows order SO42− > Cl− HCO3− Na+ Mg2+ Ca2+ K+. (2) concentrat...

The mineralogical composition, microstructure, and reactivity of traditional gypsum, a multiphase product, is closely connected to its calcination temperature, but systematic studies which relate those features mechanical properties weathering resistance plasters are scarce. Here we examined the hydration behavior gypsum calcined between 100 1000 °C, contained varying amounts uncalcined bassani...

This paper describes some physical, structural, and biological properties of gypsum bioceramics doped with various amounts of strontium ions (0.19-2.23 wt%) and compares these properties with those of a pure gypsum as control. Strontium-doped gypsum (gypsum:Sr) was obtained by mixing calcium sulfate hemihydrate powder and solutions of strontium nitrate followed by washing the specimens with dis...

Syngenite (K2Ca(SO4)2 ⋅ H2O) presents an effective hydration activator (accelerator) for anhydrite (CaSO4) applied in construction systems. The current synthesis relies on co-precipitation of K2SO4 and CaSO4 2H2O produces large amounts waste water holding excess potassium sulfate. Therefore, this method is deemed ineffective, uneconomical environmentally unfriendly. Moreover, it crystals (ℓ ∼5-...

One of the most important environmental issues for decades to come is the treatment of industrial wastewaters containing salts (sulfates, chlorides, sodium, magnesium ...) which can lead to strong perturbations affecting the fauna and flora when highly concentrated at the discharge point. Different processes used to separate the dissolved salts from the liquid matrix may be encountered dependin...

This research assessed the use of gypsum (CaSO42H2O) as a skeleton builder for sludge dewatering since polymer conditioning of sludge affected only the rate of water release, not the extent of dewatering. The use of gypsum as a physical conditioner, in association with a polymer, could improve sludge filterability. More significantly, gypsum serves as a skeleton builder, forming a permeable an...

We report the δ34S and δO(SO4) measured in gypsum, pyrite, and elemental sulfur through a 456-m thick sediment core from the center of the Dead Sea, representing the last ∼200 kyrs, as well as from the exposed glacial outcrops of the Masada M1 section located on the margins of the modern Dead Sea. The results are used to explore and quantify the evolution of sulfur microbial metabolism in the D...

A numerical analysis of the evolution with time of an abandoned gypsum mine flooded by water is presented. The lay-out of the problem is shown first, together with the experimental results obtained in laboratory tests on gypsum specimens retrieved from site. An elastic-plastic strain-hardening constitutive model, capable of taking weathering effects into account, is sketched next. A chemo-mecha...