Reaction products of clay minerals with sodium hydroxide under hydrothermal conditions

Phase relations of some tungstate minerals under hydrothermal conditions

The binary phase relations ofseveral naturally-occurring tungstats mins14ls, ofthe general form M2*WOae w€t€ investigated hydrothermally at fluid pressure of 1.0 kbar and temperatures of 400o-900oc. A complete solid solution, with tetragonal symmetry, between scheelite (M2* Ca) and Stolzite (Pb) forms above725"C. The solvus is alnost symmetrical with a crest near CaorPbrr. The observed linear v...

Redox-driven dissolution of clay minerals by uranium under high pressure CO2 conditions

Synthesis of Zeolites, Merlinoite Minerals of Damavand’s Natural Clinoptiloite Zeolites Mineral in Hydrothermal Conditions, under the Influence of Alkaline

In the present research synthesis of zeolites, merlinoite minerals of natural clinoptiloite mineral in the presence of alkaline mediums, was investigated. The analyzed variants are a result of a concentration of Na+ and K+ ions, temperature and time. Phase transition of clinoptiloite was conducted in the presence of an 8 molar potash solution (KOH) and a 4 molar soda solution (NaOH). Results in...

Clay Minerals and Catalysis

More than half a century ago, Irish physicist John Desmond Bernal and Swiss geochemist Victor M. Goldschmidt independently proposed that clay minerals may have played an important role in prebiotic synthesis (Bernal 1949; Goldschmidt 1952). I concur that mineral catalysis must have had a central role in prebiotic synthesis because most uncatalyzed reactions start from simple precursors like hyd...

Clay Minerals: Adsorbophysical Properties

The structure and features of surfaces of clay minerals (kaolin, montmorillonite, etc) have an important scientific and practical value. On the surface the interrelation of processes at electronic, atomic and molecular levels is realized. Availability of mineral surface to external influences opens wide scientific and technical opportunities of use of the surface phenomena, so the research of c...