Геополимеры на основе механоактивированных смесей золы ТЭЦ с природными карбонатами кальция и магния

Nanocrystalline ytterbium zirconate Yb4Zr3O12 (δ-phase) was synthesized by the solid-state method with preliminary mechanical activation of a stoichiometric mixture of the corresponding oxides. The processes occurring in the course of the synthesis were studied by X-ray powder diffraction, IR spectroscopy, and thermal analysis. The average size of Yb4Zr3O12 crystallites obtained by annealing a mechanically activated oxide mixture at 900, 1000, 1100, and 1200°C was calculated by the Scherrer formula and was 12, 17, 27, and 41 nm, respectively.

Аннотация.Исследованы вяжущие свойства геополимерной механоактивированной композиции на

The issues of improved reactivity in geopolymerization reactions developed under effect of mechanical activation are examined in the fly ash obtained from the Apatity Heat and Electric Power Plant. The effect of normal and hydrothermal hardening of ash activated with sodium hydroxide solution is explored from the standpoint of changing the strength of geopolymers obtained.

— Nanocrystalline gadolinium zirconate, Gd 2 Zr 2 O 7 , has been prepared by solid-state reaction, using mechanical activation of a stoichiometric mixture of Gd 2 O 3 and ZrO 2 . The mechanical activation was performed in an AGO-2 centrifugal planetary mill for 10 min. The processes that occurred during heat treatment of the mechanically activated mixture of gadolinium and zirconium oxides were characterized by X-ray diffraction, IR spectroscopy, and a combination of thermoanalytical techniques. The average crystallite size of gadolinium zirconate prepared by calcining the mechanically activated oxide mixture at 1100 and 1200°C for 3 h was 29 and 68 nm, respectively, as determined using the Scherrer formula.

In this study, the effect of mechanical activation of coprecipitated hydroxide precursor on synthesis of gadolinium zirconate Gd2Zr2O7 has been studied. Mechanical activation of the precursor has been performed in an AGO-2 laboratory centrifugal-planetary mill at a centrifugal factor of 20 g with zirconia vials and balls. Particular attention has been given to carbonization of the as-prepared and mechanically activated precursors due to reaction with atmospheric carbon dioxide and their decarbonization in the course of calcination. The removal of the volatile components (H2O and CO2) from the as-prepared and mechanically activated precursors can be achieved by calcination at 1100–1200 °C for 3 h. Calcination of the as-prepared and mechanically activated precursors in the range of 700–1200 °C results in the formation of nanocrystalline fluorite-type Gd2Zr2O7. Gadolinium zirconate prepared from the mechanically activated precursor exhibits 4–9 times larger BET surface area relative to that of Gd2Zr2O7 synthesized at the same calcination conditions from the as-prepared precursor. In particular, this is beneficial for preparation of nanostructured dense ceramic materials with enhanced properties.

The problems of increasing the reactivity of fly ash of the Apatity thermal power plant in the reactions of geopolymerization occurring under the influence of mechanical activation were considered. The effect of the normal and hydrothermal curing of fly ash activated with sodium hydroxide solution on the strength of the resulting geopolymers was studied.

Синтез геополимеров на основе золы уноса с применением механоактивацииКалинкин А.М., Гуревич Б

Аннотация.В работе изучена возможность использования механоактивированных серпентинсодержащих горнопромышленных отходов без

Nanocrystalline BaZrO3 has been prepared by solid-state reaction, using preliminary mechanical activation of a stoichiometric mixture of BaCO3 and ZrO2. The mechanical activation was performed in an AGO-2 centrifugal planetary mill for 10 min at a centrifugal factor of 40g. The effect of mechanical activation of the reactant mixture on the processes that take place during subsequent heating of the mixture has been studied using a combination of thermoanalytical techniques. The synthesized barium zirconate, with an average crystallite size from 50 to 100 nm, has been characterized by X-ray diffraction and scanning and transmission electron microscopy.

Nanocrystalline lanthanum zirconate La2Zr2O7 was synthesized by the solid-phase method using preliminary mechanical activation of a La2O3 and ZrO2 mixture. Processes occurring during heating the mixture of mechanoactivated lanthanum and zirconium oxides were studied using the X-ray phase analysis, IR spectroscopy, and complex thermal analysis. Synthesized lanthanum zirconate was characterized by the X-ray phase analysis and transmission electron microscopy methods.

Nanocrystalline SrZrO 3 has been synthesized by a solid-state procedure using mechanical preactivation of a strontium carbonate–zirconia mixture in an AGO-2 centrifugal planetary mill. The effect of mechanical activation of the reactant mixture on the processes occurring during its subsequent heating has been studied by thermal analysis. The resulting strontium zirconate has been characterized by X-ray diffraction and by scanning and transmission electron microscopy.