Magnesium-silicate scaling in mixture of geothermal water and deaerated fresh water in a district heating system

Signatures of biologically influenced CaCo3 and Mg–Fe silicate precipitation in hot springs: Case study from the Ruidian geothermal area, western Yunnan Province, China

“…15H to L) appearance. Reticulate coatings, characterized by their mesh-like structure and variable elemental contents (for example, Si, Mg, Al, Fe, Ca, Na, Cl and Mn), are known from hot spring deposits in the African Rift Valley (Casanova & Renaut, 1987;Casanova, 1994;Jones & Renaut, 1996a,c), hot spring deposits in New Zealand (McKenzie et al, 2001;Jones et al, 2003), in scale that lines pipes in the geothermal systems of Iceland (Gunnlaugsson & Einarsson, 1989;Kristmannsdottir et al, 1989;Sverrisdottir et al, 1992), submarine hot springs in Iceland (Geptner et al, 2002) and in speleothems found in wave-cut notches (Jones, 2010) and caves (L eveill e et al, 2000a,b;Polyak & G€ uven, 2000Polyak & G€ uven, , 2004. Their precise mineralogy is difficult to establish because they form such thin coatings that it is generally impossible to extract them for XRD analysis and most appear non-crystalline with microscale variations in element concentrations.…”

Precipitation of poorly crystalline antigorite under hydrothermal conditions

“…Scales of poorly crystalline magnesium silicate have formed in geothermal installations when magnesium-bearing ground water is heated and when high-pH geothermal waters are mixed with Mg-bearing nonthermal waters. Several studies have been carried out to reveal the nature of the magnesium silicate precipitated in geothermal installations (Kristmannsdóttir, 1980;Kristmannsdóttir et al, 1999;Sverrisdóttir et al, 1992), and the conditions under which they form (Gunnlaugsson and Einarsson, 1989;Hauksson et al, 1992;Hauksson and Thórhallsson, 1993). Evaluation of potential magnesium silicate scaling from exploited geothermal waters requires knowledge of the solubility of the magnesium silicate phase involved, and the water saturation state with respect to that mineral.…”

Types of the scaling in hyper saline geothermal system in northwest Turkey

“…Geothermal fluids are saturated with silica and are typically close to saturation with calcite, calcium sulphate, calcium fluoride, magnesium silicate, aluminium-silicates, opaline silica, iron-magnesium-silicates, and metal sulfide (Gunnlaugsson, 1989;Kristmannsdóttir, 1989;Honegger et al, 1989;Ölç enoglu, 1986;Patzay et al, 2003). The reduction of temperature and pressure during production lowers the solubility and causes prodigious precipitation known as scaling.…”