Preparation method of magnesium-iron composite alumina spinel brick for rotary kiln for co-processing hazardous waste

Abstract

The invention provides a preparation method of a magnesium-iron composite alumina spinel brick for a rotary kiln for co-processing hazardous waste. The preparation method of the magnesium-iron composite alumina spinel brick for a rotary kiln for co-processing hazardous waste comprises the following steps: S1, a production process of the magnesium-iron composite alumina spinel brick; a, standards of raw materials: raw materials are selected for chemical component analysis, and the requirements are as follows: (1) fused magnesia contains more than or equal to 97% of MgO, less than or equal to 0.8% of SiO2, less than or equal to 0.8% of Fe2O3 and less than or equal to 1.0% of CaO; (2) sintered iron sand contains more than or equal to 97% of MgO, less than or equal to 1.0% of SiO2, less than or equal to 1.0% of Fe2O3 and less than or equal to 1.5% of CaO; and (3) hercynite contains less than or equal to 1.0% of MgO, less than or equal to 0.8% of SiO2, more than or equal to 35% of Fe2O3, more than or equal to 58% of Al2O3 and less than or equal to 1.0% of CaO. According to the preparation method of a magnesium-iron composite alumina spinel brick for a rotary kiln for co-processing hazardous waste, provided by the invention, the magnesium-iron composite alumina spinel brick has good erosion resistance, good kiln coating hanging performance and good thermal shock resistance.

Description

technical field [0001] The invention belongs to the technical field of magnesia-iron composite alumina spinel bricks, and in particular relates to a preparation method of magnesia-iron composite alumina spinel bricks for co-processing hazardous waste rotary kilns. Background technique [0002] The refractories used in the firing zone of large cement rotary kilns must have high temperature resistance, alkali resistance, wear resistance, thermal shock resistance and excellent kiln skin resistance. Although traditional magnesia-chrome bricks have the above advantages, their It also has the biggest weakness---chromium, which is easy to cause pollution, and the main ways of pollution are: during the calcination process of cement clinker, when the chromium-containing refractory material exists in an oxidizing atmosphere and alkaline oxide, at a certain temperature, Cr+ 3 Part of it will be converted into Cr+6 which is harmful to humans, and will be mixed into cement clinker with t...

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Problems solved by technology

[0002] The refractories used in the firing zone of large cement rotary kilns must have high temperature resistance, alkali resistance, wear resistance, thermal shock resistance and excellent kiln skin resistance. Although traditional magnesia-chrome bricks have the above advantages, their It also has the biggest weakness---chromium, which is easy to cause pollution, and the main ways of pollution are: during the calcination process of cement clinker, when the chromium-containing refractory material exists in an oxidizing atmosphere and alkaline oxide, at a certain temperature, Cr+ 3 Part of it will be converted into Cr+6 which is harmful to humans, and will be mixed into cement clinker with the peeled refractory material, resulting in excessive chromium content in cement, so the "chromium public nuisance" problem caused by chromium-containing refractory materials used in cement kilns It has increasingly attracted people's attention and attention. Industrial developed countries such as Europe, America, and Japan have passed legislation to explicitly prohibit or restrict the use of magnesia-chrome bricks in cement kilns, and China has also proposed environmental protection requirements for the clean production of the cement industry. One is to adopt Relatively environmentally friendly low-chromium magnesia-chrome bricks, although to a certain extent retains the characteristics of magnesia-chrome bricks sticking to the kiln skin and reduces the environmental pollution of waste magnesia-chrome bricks, but still does not completely solve the problem of Cr6+ pollution; Chromium-containing refractory materials, such as magnesia dolomite bricks, magnesia-iron composite alumina spinel bricks, but magnesia-iron composite alumina spinel bricks have not been fundamentally resolved due to the hydration of CaO in raw materials in China, and there are still the following disadvantages:

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