Compact CA2-CA6 composite phase lightweight fire-proof clinker and preparation method thereof

Abstract

The invention relates to a compact CA2-CA6 composite phase lightweight fire-proof clinker and a preparation method thereof, wherein the components comprise, by weight, 77.2-84.6% of Al2O3, 11.4-20.8% of CaO, and 2.0-4.0% of MnO, the relative density is 91.3-95.2%, and the apparent porosity is 2.6-3.8%. The preparation method comprises: (1) respectively carrying out fine grinding on bauxite and limestone, and mixing; (2) pressing the mixed material into green pellets, and carrying out first calcination to produce the clinker; (3) carrying out fine grinding on the clinker, adding manganous oxide micro-powder, and pressing into pellets; and (4) carrying out second calcination. According to the present invention, the manganous oxide micro-powder is adopted as the sintering promoting agent, and manganous oxide solid is dissolved into the CA2 and CA6 crystal phase during the calcination process to form the solid solution, such that the occurrence of the lattice distortion of the CA2 and CA6 phase is promoted, the activity is improved, and the sintering and compacting behavior of the CA2-CA6 composite phase lightweight fire-proof clinker is effectively promoted so as to obtain the compact CA2-CA6 composite phase lightweight fire-proof clinker under the conditions of the low two calcination temperatures and the short thermal insulation time.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, in particular to a dense CA 2 -CA 6 Composite lightweight refractory clinker and its preparation method. Background technique [0002] Calcium dialuminate (CaO 2Al 2 o 3 , referred to as CA 2 ) and calcium hexaaluminate (CaO 6Al 2 o 3 , referred to as CA 6 ) is CaO-Al 2 o 3 Important high melting point compounds in binary systems. Among them, CA 2 Its own thermal expansion coefficient is low, and at the same time, when it is combined with other materials with high melting point and high expansion coefficient, it can well reduce the thermal expansion coefficient of the composite material, and has quite good thermal shock stability; CA 6 Low solubility in iron-containing slags, high stability in reducing atmospheres (CO), good chemical stability in alkaline environments, low wettability to molten metals and slags (steel and non-ferrous metals) , so it is very good resistanc...

AI Technical Summary

Problems solved by technology

[0004] Preparation of Dense Ca in Solid-Phase Synthesis 2 -CA 6 In the process of multiphase lightweight refractory clinker, due to the CaO-Al 2 o 3 There are many chemical reactions inside refractory materials under high temperature conditions, and the volume expansion effect accompanied by the reaction between components inhibits the sintering and densification process, and it is difficult to obtain dense refractory clinker through one-time calcination; at the same time, due to CA 6 The sintering activity of the phase is low, and it is difficult to obtain dense clinker even after two calcinations, so it is generally required that the sintering temperature should not be lower than 1700 ° C; in addition, due to the CA 6 The easy dendrite bridging interconnection between crystal phases forms a network porous structure, which further affects the CA 2 -CA 6 Sintering densification of composite lightweight refractories