Thermal Behavior of Estonian Graptolite–Argillite from Different Deposits

Graptolite–argillites (black shales) are studied as potential source of different metals. In the processing technologies graptolite–argillites, a preceding thermal treatment is often applied. this study, behavior Estonian graptolite–argillite (GA) samples from Toolse, Sillamäe and Pakri areas were using Setaram Labsys Evo 1600 thermoanalyzer coupled with Pfeiffer OmniStar Mass Spectrometer. The products by XRD, FTIR, SEM analytical methods. experiments carried out under non-isothermal conditions up to 1200 °C at heating rates in atmosphere containing 79% Ar 21% O2. differential isoconversional Friedman method was applied for calculating kinetic parameters. All GA characterized high content orthoclase (between 38.0 57.3%) quartz 23.8 35.5%), lower muscovite, jarosite, pyrite, etc. organic carbon varied between 7.3 14.2%. results indicated that, 200 °C, emission hygroscopic physically bound water takes place. Between 500–550 followed thermo-oxidative decomposition matter. first step thermo-oxidation pyrite water, sulphur dioxide, nitrogen oxides, hydrocarbon fragments complicated composition At higher temperatures, 550 900 transformations continued dehydroxylation processes clay minerals, jarosite carbonates took temperatures above 1000–1050 slow increase dioxide followed, indicating beginning second which not completed 1000 °C. Kinetic calculations prove mechanism samples: samples, it occurs two steps, Silllamäe Toolse three steps. Preliminary tests estimation influence pre-roasting on solubility elements contained following leaching sulphuric acid based sample.