The secondary gypsum facies are formed after hydration of anhydrite and anhydritizated primary gypsums. Additionally, mineralogical and geochemical …

The objective of our research is to improve some laboratory procedures in order to determine and quantify gypsum in the soil, especially secondary accumulations. We applied several methods of sample handling and …

Obtained secondary gypsum binder was tested on consistency, density, setting time, and strength. The standard consistency of Suttard ring flow at 180 mm was achieved and with such, W/B ratio …

The gypsum mined is, in many cases, of secondary type; that is to say, it comes from anhydrite that is hydrated on the surface due to meteoric waters. The extent of this secondary gypsum depends on the hydration zone of the anhydrite beds from which it originates, which is not usually regular and, in many cases, does not form uniforms layers.

Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate (CaSO4·2H2O). It is commonly found in sedimentary rock formations and is often associated with other minerals such as anhydrite, halite, and sulfur. The name "gypsum" is derived from the Greek word "gypsos," which means "plaster" or "chalk.".

A number of other secondary minerals were considered for mixing with the gypsum and steel slag from the basic oxygen process was found to be most successful. An optimised mix was developed and a ...

Each and every secondary nutrient plays a dominant role in the plant nutrition management. Increased need of Calcium, Magnesium and Sulphur by crop plants in addition to primary nutrients such as N, P & K has led Greenstar to market CMS in the form of granulated and powder form of 'Keerthi' and Phosphor Gypsum in bulk and bagged as …

of secondary gypsum as an alternative to primary gypsum. T welve boreholes were drilled for a depth of 2 m, as the thickness of suitable secondary gypsum layer ranges from 1 to 1.5 m.

The Use of Secondary Gypsum to Make a Controlled Low Strength The Open Construction and Building Technology Journal, 2008, Volume 2 297 D C D F A A B E Fig. (2). Phase "A" is an iron-rich inclusion, "B" is a calcium-iron-manganese-magnesium oxide, phase "C" is a calcium silicate, approxi- mating to impure wollastonite and "D" is ...

39. Classification of forms of secondary carbonates 38 40. Classification of gypsum content 39 41. Classification of forms of secondary gypsum 39 42. Classification of salt content of soil 40 43. Dependency of water content of saturation extract on texture and content of humus for mineral soils and on decomposition for peat soils 41 44.

Gypsum is a common primary and secondary mineral of arid and semi-arid region soils. Gypsum is by far the dominant sulfate mineral in soils. It is …

FGD gypsum used as a replacement for mined gypsum in wallboard (referred to as "FGD gypsum wallboard") during use by the consumer. ... The BU Methodology presents an approach for evaluating a wide range of industrial non-hazardous secondary materials and their associated beneficial uses. As such, it may be used to …

Gypsum: Schofield P F, Knight K S, Stretton I C (1996) Thermal expansion of gypsum investigated by neutron powder diffraction American Mineralogist ... Breit, G.N. (2005) Origin of secondary sulfate minerals on active andesitic stratovolcanoes. Chemical Geology: 215: 37: 60. Lane, M.D. (2007) Mid-infrared emission spectroscopy of sulfate and ...

Abstract. Secondary gypsum rocks, formed from anhydrite by the action of ground waters and/or surface weathering and unmodified by tectonic influences, are …

From the results, both secondary gypsum and syngenite formation caused faster stiffening and set. The amount of syngenite produced during 1 hour hydration was approximately 1 % of total mass of ...

the properties of gypsum binder obtained from secondary raw materials originating from CDW. Three types of drywall boards and cast monolithic gypsum from interior walls, treated in the laboratory,

Soil in arid and semi‐arid regions are differentiated to Solonchaks with a high content of soluble salts, Solonetz with a high percentage of adsorbed sodium ions, Gypsisols with a horizon of …

1). Then gypsum CDW was milled to powder-like particles by collision milling in a semi-industrial disintegrator with a rotational speed of 50 Hz [14]. The obtained gypsum pow-der was used for further research as a secondary gypsum binder. Figure 1. The treatment process of CDW to obtain secondary gypsum powder for binder produc …

The gypsum content may be due to an accumulation of secondary gypsum, the transformation of primary gypsum inherited from parent material, or other processes. Suffix yy is used when the horizon fabric has such an abundance of gypsum (generally 50% or more, by volume) that pedogenic and/or lithologic features are obscured or disrupted …

The primary facies include massive gypsum and Anhydrite. The secondary facies comprise stainspar and laminated-banded gypsum facies (Figure 8). In addition to these facies, clastic and carbonate layers are observed along the sections as interbands or intercalations between and at the bottom of the formation facies (Figure 8).

Secondary gypsum with different dimensions formed with the effect of SSA in the studied samples. SEM–EDX determinations showed that there was a direct correlation between the shape size and the sulfur content of gypsum crystals. NSA treatment induced physical changes on the limestone surfaces. Accordingly, the crystal morphology of …

Secondary gypsum usually cuts through the bedding and occurs in veins . Based on a previously recovered drill core, the evaporites are composed of gypsum, anhydrite, and rock salts . The thickness of the rock salt is up to 356.8 m. It mainly consists of clay gravel and halite, and it exhibits tectonic reworking, salt solution, and leaching.

The formation of secondary gypsum was more evident in samples where calcium sulfate was more soluble (calcination at 350 °C with higher alkaline activator content) and at higher quantities (20%). The intense formation of secondary gypsum proved to be very harmful to compressive strength; 3. The largest formations of ettringite …

The combined effect of acidic and oxidation reactions caused the fracture initiation and propagation, where the acidic reaction of calcite was dominant while oxidation reactions were secondary. Gypsum (CaSO 4 ⸱2H 2 O) crystallization was formed after Na 2 S 2 O 8 imbibition and the crystallization-induced stress was one of the favorable ...

Evidence for low-salinity gypsum in the Messinian Salinity Crisis comes primarily from the study of gypsum primary fluid inclusions. These suggest average salinities of gypsum parent waters equal to 16 g kg −1 in the Piedmont Basin (northern Italy) (Natalicchio et al., 2014), 32 g kg −1 in the Sorbas basin (Spain) (Evans et al., 2015) and …

Gypseous (high-gypsum) soils generally occupy sparsely populated land with minimal land use intensity in arid and semiarid climates. Gypsum content in …

natural gypsum and secondary gypsum resources [1]. Natural gypsum is mainly gypsum ore, which is divided into dihydrate gypsum ore (CaSO42H2O) and anhydrite ore (CaSO4) according to the chemical composition. The natural gypsum is mainly used as a cement manufacturing retarder [1–3], while secondary gypsum …

Soils having a (petro-)gypsic horizon (horizon with accumulation of secondary gypsum) or 15 percent or more gypsum accumulated under wet conditions. They have no diagnostic horizons other than an ochric or cambic horizon, an argic horizon permeated with gypsum or calcium carbonate, or a (petro-)calcic horizon below the gypsic horizon. ...

The Use of Secondary Gypsum to Make a Controlled Low Strength Material. This paper reports on the use of secondary minerals to make Controlled Low Strength Materials for trench or mine backfill. The mixes used red titanogypsum which is a by-product of titanium dioxide pigment production. A number of other secondary minerals were …

Alabaster is secondary gypsum very fine-grained and formed by replacement of anhydrite (Yilmaz and Karakan 2005). Porphyritic was observed as larger gypsum crystal (phenocrysts) sets in a finer-grained secondary gypsum groundmass. Concerning the field study, porphyritic gypsum is outcropped in the south and east of the …