The effect of maturation upon the mineralogical and physicochemical properties of illitic-smectitic clays for pelotherapy

Abstract

A B S T R A C T : Illitic-smectitic clays were matured with a ferruginous, bicarbonate-rich and sulphate-rich water for different periods of time (7, 15, 30, 60 and 90 days), and subjected to discontinuous stirring, to test their use in pelotherapy. A progressive degradation of the clay minerals was observed during the maturation process, with a reduction in the illite and smectite crystallinity, in the percentage of smectites and in the phyllosilicate content. The percentage of <2 mm particles also decreased. These modifications caused changes in the clays' physicochemical properties, which are evident in an increase in their plasticity index and in slower cooling of the peloid, both of which improved the clays' effect in pelotherapy.

Assessment of three Spanish clays for their use in pelotherapy

“…Furthermore, some properties of peloids prepared with clays, different types of water and different maturation conditions have been studied Curini et al, 1990;Fernández-González et al, 2013;Gámiz et al, 2009;Quintela et al, 2010;Sánchez et al, 2002;Tateo et al, 2010;Veniale et al, 2004). However, these studies include only some of the properties important in pelotherapy while others do not consider the modifications to these properties which occur during preparation of the clay-water mixture prior to maturation.…”

Thermal mud maturation: organic matter and biological activity

“…During the last few years, some scientific studies have focused on characterization of the muds and evaluation of the maturation process. These investigations have looked at the changes in the physico-chemical properties of thermal mud induced by maturation, using various instrumental techniques [4,8,[11][12][13]; the microflora has been examined [14][15][16][17] and the organic matter determined, particularly the lipid fraction [15,[18][19][20][21][22][23][24][25][26][27].…”

A study of the chemical, mineralogical and physicochemical properties of peloids prepared with two medicinal mineral waters from Lanjarón Spa (Granada, Spain)

“…This process, known as aggradation (Pédro, 1987) has been described in soils treated with potassium fertilizer (Velde and Barré, 2010). However, in the specific literature for peloids, the opposite process has been described, whereby crystalline perfection decreases in the saponites during maturation (Sánchez et al, 2002). We believe that this case is due to the water employed (ferruginous, bicarbonated and sulphate-rich), which may have degraded the clay minerals.…”

“…The process known as peloid maturation is necessary to improve and stabilize their therapeutic properties (Sánchez et al, 2002) and small changes in mineralogy may occur during this process (Tateo and Summa, 2007). Maturation is a process of mixing and resting with periodic shaking of the materials over a specific time period in order to homogenize and optimize the properties of the peloid while also developing some specific properties (Carretero et al, 2006;Veniale et al, 2004).…”