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Registration Number

0216U007284, 0115U001504 , R & D reports

Title

Production technology reprocessing of mix from stabilized zirconia and pilot batches of powders for plasmic coating, ramming mixes and mortars from ZrO2 and periclase chromate powders out put.

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Head

Shulik I.,

Registration Date

17-06-2016

Organization

Public joint stock company "The Ukrainian research institute of refractories named after A.S.Berezhnoy"

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The object of the research is the stabilized zirconium dioxide mass. The objective of the work is refine of production technology the stabilized zirconium dioxide masse. Research methods are chemical, petrographic, electron microscope, X-ray diffraction. The influence of heat treatment temperature (150-2200 °С) on the main indicators properties of zirconium dioxide samples, stabilized by combined additive of CaO and MgO, on phosphate binder, has been researched. It has been found, that with increasing heat treatment temperature up to 1200-1400 °С open porosity of samples increased from 12.8 to 15.7-16.3 % at values apparent density, constituting 4.62-4.64 g/cm3, due of process destabilization of ZrO2 at these temperatures. A further increase temperature up to 1750 °C, due to the sintering process and the beginning of re-stabilization, reduces the values of the open porosity to 14.4 % at values of apparent density 4.68 g/cm3. Increasing temperature to 2000-2200 °C results in insignificant increase of open porosity - 16.9-19.0 % (apparent density 4.56-4.58 g/cm3), due to a decrease in the number of closed and coalescence of open pores. The samples in investigated temperature range, characterized by high cold crushing strength - 50-74 MPa, and a slight growth (+0.2)-(+0,9) %. The processes of phase-formation zirconium dioxide samples, stabilized by combined additive of CaO and MgO, on phosphate binder in the temperature range 150-2200 °C has been researched. It has been determined, that the most complete interaction Р2О5 with filler and fine binder of samples occurs in the temperature range 1200-1400 °C and is manifested in significant destabilization of the cubic phase of ZrO2, but does not lead to abrupt loss of samples strength (cold crushing strength reduced from 74 to 60 MPa), as when using stabilizing additives of CaO or Y2O3 (cold crushing strength 18-24 MPa), forming with Р2О5 a crystalline phosphate, causing softening of samples. Increasing of heat treatment temperature of samples up to 1750-2200 °C causes to dissolving of phosphates and leads to a re-stabilization of ZrO2, which contributes to the gradual hardening of the samples by sintering and formation, from 2000 °C, the lamellar structure, cementing filler grain. It has been determined, that at the phase-formation process in temperature range 150-2200 °C strength of the samples, from the developed mass, is high, which provides the structural strength of the lining in the service. The researches of influence of the combined phosphate binder from calcium dihydro-phosphate and phosphoric acid in the ratio of 1:3, 1:1 and 3:1, at the main indicators properties stabilized zirconium dioxide samples, have been carried out. Developed the combined phosphate binder, consisting of calcium dihydro-phosphate and phosphoric acid in a ratio of 1:3, the use of which achieves close values properties, compared with the samples of bonded phosphoric acid (heat treatment temperature - 1580 °C): apparent density 4.56 and 4.59 g/cm3, open porosity 15.4 and 14.3 %, cold crushing strength 34 and 37 MPa respectively. This binder is recommended for the manufacture of vibrocast intricate-shaped configuration products, the application of which will improve the life-time of the metal molds. As a result of research, production technology the zirconium dioxide mass, stabilized combined additive, has been improved. Pilot batch of the mass, manufactured at the pilot plant of the Institute, transmitted to the Omsktechuglerod OOO for testing in service and installed in the lining of reactor's combustion chamber of carbon black production, which in may 2015 was put into operation. On the composition of the highly-refractory zirconium dioxide mass, combined additive of CaO and MgO, pending the alleged invention. Pilot batches have been made: mixture of powders to a packed mass brand СМЦН-93, as well as mortar brand МЦ-93-1; powders for plasma spraying brands: ПЦПК-100, ПЦПК-63, ПБПК-63-1, ПЦПК-40, with indicators properties, the relevant technical requirements of Ukraine; periclase powder fraction < 1 mm with indicators properties, the relevant requirements of the consumer. These refractory products have been supplied to consumers in the domestic and foreign markets (exports to Russia). Work should continue in the direction of further improvement of production technology stabilized zirconium dioxide mass.

Product Description

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Шишковський Д.О.

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2020-04-02