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The dehydration of CoHPO4 · 1.5H2O has been followed by means of thermal analyses at quasi isothermal-isobaric conditions. The intermediates and products prepared in the course of the TA and by calcination of the starting hydrogen phosphate in electric ovens at various temperatures have been analyzed and identified by means of thin-layer chromatography, IR spectroscopy, X-ray diffraction analysis and electron microscopy.

Some condensed phosphates, especially cyclo-tetraphosphates have been synthetized as new binary compounds and their existence has been proved. The synthesis of cyclo-CdMgP4O12 is shown as an example. The products crystallize in the monoclinic system (C2c group) and are stable to 900°C. The synthesis is based on a thermal procedure making use of the reversible transformation of cyclo-tetraphosphates to higher linear phosphates (the 1.method) and on a calcination of the starting binary dihydrogenphosphate at quasi-isothermal-isobaric conditions (the 2.method).

The decomposition of hydronium jarosite occurs in two temperature ranges: first a loss of 8 moles of H2O from 2 moles of jarosite, then in the second step one mole of H2O and 4 moles of SO3 are simultaneously evolved. Fe(OH)(SO4)2 and Fe2O(SO4)2 are assumed intermediates. During the thermal treatment of Na or K jarosits, only Fe2(SO4)3 appears as intermediate. The decomposition temperatures are significantly influenced by the type of crucible used (determination of partial pressure of gaseous decomposition products). The particle size distribution of the starting jarosite has no effect upon the temperature of the decomposition steps and of the reaction with ZnO.

Thermal analyses under quasi-isothermal-isobaric conditions were used to follow the condensation reactions proceeding during the calcination of zinc hydrogenphosphate. Its calcination in an electric oven under isothermal conditions was adopted for preparation of the intermediates and the main product, which were analysed by chromatography, IR spectroscopy, NMR spectroscopy, X-ray analysis and electron microscopy.

Binary cyclo-tetraphosphates Me2II-xMxIIP4O12 were synthetized via the thermal decomposition and recrystallization of polyphosphate glasses, i.e. binary higher linear phosphates (Me2II-xMxII)n/4H2PnO3n+l. The syntheses ofc-Zn2-xMgxP4O12 andc-Zn2-xCaxP4O12 are presented as examples.

Cyclo-tetraphosphates M2II-xMxIIP4O12 have been synthetized by thermal dehydration of dihydrogenphosphates. The syntheses of the binary cyclo-tetraphosphatesc-Zn2-xCaxP4O12 andc-Mn2-xMgxP4O12 are presented as examples.

The dehydration and condensation reactions taking place during the calcination of Mn1/2Ca1/2(H2PO4)2.2H2O has been followed by means of thermal analyses under quasi-isothermal-isobaric conditions. Isothermal calcination of starting binary dihydrogenphosphate has been also carried out in an electric oven at various temperatures. The reaction products obtained were analyzed by chromatography, IR-spectroscopy, X-ray diffraction analysis, and electron microscopy. The compositions of the calcinates were determined through extraction. The effect of the partial pressure of water vapour has been followed on course, of the condensation reactions and of the formation of the main product: binary cyclotetraphosphate (tetrametaphosphate) MnCaP4O12.

The mechanism of the dehydration and condensation reaction taking place during calcination of Co1/2Ca1/2(H2PO4)2.2H2O has been followed by means of thermal analyses at non-isothermal (dynamic) and at quasi-isothermal-isobaric conditions. Isothermal calcination of starting binary dihydrogenphosphate was carried out in electric oven at various temperatures. The reaction intermediates and products obtained were analyzed by instrumental analytical methods and extraction experiments with solutions of inorganic compounds and with organic reagents. Effect of water vapour pressure has been followed on course, rate and yield of the condensation reactions and of the formation of main considered product-binary cyclo-tetraphosphate (tetrametaphosphate)c-CoCaP4O12.

c-CuMgP4O12 is an industrial product used for various practical purposes. Its preparaton from Cu1/2Mg1/2(H2PO4)2.0.5H2O by calcination was studied by means of thermal analysis and extraction methods under different experimental conditions, in particular at different partial pressures of water vapour with the sample in contact. The intermediates and end-products were identified and the optimal conditions for the formation ofc-CuMgP4O12 are given.

The dehydration of CuHPO4·H2O was followed by means of thermogravimetric measurements under quasi-isothermal-quasi-isobaric conditions. The intermediates and products formed during The thermal analysis and during the calcination of the starting hydrogen phosphate in an electric furnace at various temperatures were analysed by means of thin-layer chromatography, IR spectroscopy, X-ray diffraction analysis and electron microscopy.

With the application of thermogravimetry under quasi-isothermal-isobaric conditions, the reaction course of the calcination of Mn(H2PO4 · H2O to give dimanganese cyclotetraphosphate has been studied. Isothermal calcination was also carried out in an electric furnace at various temperatures (200 min). The reaction products were analyzed by chromatography, IR and NMR spectrocopy, and X-ray diffraction analysis. The compositions of the calcinates were determined through extraction with various inorganic and organic solvents.

In our laboratory, the synthesis of new inorganic pigments is followed by thermal analysis using a Derivatograph apparatus. The first information about the temperature region of the formation of the pigments investigated is provided by thermal analysis. The main attention is directed to the preparation of high-temperature colour pigments, lightfastness colour pigments, anticorrosive pigments, new ecological inorganic pigments and luminescent pigments. All inorganic pigments are useful for colouring of ceramic glazes, enamels, plastics, paints, cements and other building systems. The synthesis of all these pigments is based on temperature calcination of starting materials. Tens of new inorganic pigments have been prepared thanks to methods of thermal analysis. These synthesis are described in more than 100 Czech patents.