Flexible periclase compound spinel brick

Abstract

A flexible periclase compound spinel brick solves the problems of the structure spalling and the environmental pollution of the generated sexivalence chromium salt which are always existed in the traditional magnesia-chromite brick. The manufacturing process thereof comprises sand making and brick making; firstly, a solid solution, the inner core of the body of which contains Al2O3, Cr2O3 and MgO, is prepared; the outer edge of the body is special synthesized solid solution sand formed by layer belts containing magnesium aluminate spinel; and then ynthesized solid solution sand used as one of brick making ingredient, prefabricated magnesite clinker, and periclase spinel selected according to the requirements are made into the periclase compound spinel brick according to the requirements of the set technological conditions. The brick conditionally retains a defined amount of chromium and has good hanging kliner coating performance, and obviously reduces the capability of generating sexivalence chromium salt owing to changing the mode of existence of Cr2O3 in the brick. When the brick is used, a metamorphic zone belt does not appear, thus fundamentally eliminating the recurring illness of the structure spalling generation in the use course and prolonging the service life.

Description

technical field [0001] The invention relates to a refractory material, in particular to a flexible periclase composite spinel brick which is specially used for the firing zone of a cement kiln, has no structure peeling off, has a long service life and can effectively reduce hexavalent chromium salt. Background technique [0002] There are two major technical problems in the existing magnesia-chrome bricks used in the firing zone of cement kilns: [0003] One is that magnesia-chrome bricks produce hexavalent chromium salts that are harmful to humans and the environment during production and use. [0004] In 1931, German doctor E. Pfeiel discovered that the employees of chromate factories had lung cancer. Further research found that the water-soluble hexavalent chromium salt that entered the human body penetrated into the cells and reduced to trivalent chromium to form carcinogens, which in turn caused cell mutations and cancerous. All countries in the world attach great imp...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a flexible periclase composite spinel, which solves the problems of structural spalling and the generation of hexavalent chromium salts that have always existed in traditional magnesia-chrome bricks, and its structural design is reasonable. While retaining an appropriate amount of chromium conditionally, it not only changes the inner Cr 2 o 3 Existing form, significantly reduces the ability to generate hexavalent chromium salt, and also achieves good performance of hanging kiln skin, no structural deterioration after use, fundamentally eliminates the stubborn disease of structural peeling, and prolongs the service life