Resource and energy saving technologies of refractory linings of thermal units

Abstract

Abstract. In Russian practice, the vast majority of thermal units and other industrial furnaces are still built with the use of single-piece ceramic refractories. The purpose of research was to develop a wide range of special materials suitable for repairs of any linings of thermal units. In accordance with the purpose, this paper solved the following tasks: Selecting reactive binders used in the compositions of refractory concrete capable of structural modification of any refractory lining materials; Developing impregnating-coating compositions based on reactive binders capable of forming a protective coating with high adhesive strengthen linings; Developing compositions of refractory ramming mixtures, used for the repair of large fragments of linings and having high adhesion to any refractory lining materials; Checking the effectiveness of the technology in production environment. In this paper, we used not only standard techniques but also specially designed ones, in particular, to determine the adhesion of refractory coating to the refractory lining materials. The technology of repair works consists of application of some or all of the above solutions depending on the state of worn out lining of the thermal unit. Testing was carried out on many sintering plants of Samara region where rotary kilns are operated. The use of such chemically active substances as phosphate bonds and sodium silicate solutes in special refractory repair compositions with different functional purpose, allowed increasing the durability of liners of expanded fire clay rotary kilns as a result of reparatory works. Some items from the general technological scheme of repair works to restore the linings of heating units may be used in industrial furnaces in many industries.

Šamotinio ugniai atsparaus betono šarminio atsparumo tyrimai

“…Medžiagų atsparumą cheminei korozijai padidinti leidžia impregnavimo technologija. Tam naudojamos įvairių medžiagų suspensijos ( Kobayashi 2003 United States Patent US 6,667,074 B2;Slovikovskii et al 2016) ir rišikliai (Khlystov et al 2017), kai stengiamasi sumažinti medžiagos poringumą. Tačiau, naudojamų impregnavimui medžiagų vaidmuo gali būti ir kitas.…”

Analysis of the Structure and Durability of Refractory Castables Impregnated with Sodium Silicate Glass

“…These castables incorporate various ultra-dispersive additives, such as silica fume and calcined alumina, alongside deflocculants that effectively diminish cement content to a mere fraction compared to conventional refractory castables [21]. However, it is important to note that these low and ultra-low-cement castables often prove sensitive to factors such as ambient conditions, water content, mixing parameters, and more, making the production process challenging [22][23][24].…”

“…Meanwhile, medium-cement castables have gained recognition for their capacity to maintain consistent quality even under varying manufacturing conditions, setting them apart as a favorable choice for biofuel boiler installations [22,23]. While the lower porosity of castables can undoubtedly enhance their durability within alkaline environments, it is important to acknowledge that over time, alkali may still infiltrate the castable structure and engage with aluminosilicate aggregates [21].…”

“…Impregnation (immersion of the samples in the special fluid) of the material could also be an effective method to substantially decrease the porosity of refractory castables and increase their alkali resistance. In the field of impregnation technology, suspensions of various materials are employed [22,23], and the specific materials used for impregnation can vary in their roles. The authors in [27] reported a significant enhancement in corrosion resistance of a chromium-magnesium material after impregnation with suspensions containing nano-Cr 2 O 3 and nano-Fe 2 O 3 particles.…”