Dolomite is abundant in my reserves, mainly in Hebei, Hubei, Guangxi, Shaanxi and other places, processing equipment is mainly used for ultrafine mill dolomite processing. Dolomite is the main basic refractories. Because it combines the characteristics of limestone and periclase, it has high alkalinity, high temperature resistance, stable thermodynamic properties, strong thermal shock resistance, and can be used to purify molten steel, resist corrosion, etc. advantage. The early dolomite refractories synthesis process used a two-step roasting method: the dolomite was directly fired into a dense sintered body at a high temperature, and was then crushed using an ultra-fine pulverizer, but the process was affected by the uneven composition of natural dolomite. Due to the high impurity content and other conditions, its performance has been greatly affected.
At present, the two-stage roasting method of dolomite is mainly used: the mixture of MgO and CaO produced by dolomite in the calcination condition of 1000°C--1200°C is called light-burned dolomite, and its activity is large and it is prone to hydration. The formation of Mg(OH)2 and Ca(OH)2 has affected their dosage and performance. When using ultrafine mill, due to the presence of hydration, refractory bricks produced from light-burned dolomite can easily absorb moisture from the air to form hydrates, which can result in the chalking of calcium-magnesia brick products. crack.
In order to enhance the hydration resistance of light-burned dolomite, secondary baking is usually performed at a temperature of 1400° C.-1500° C., and the resulting mixture after the second baking is called dead burned dolomite, which has small activity, high stability, and high crystallinity. The chemical composition is distributed evenly and the structure is compact. It also improves the hydration resistance and slag erosion resistance of dolomite refractories. It can be produced under the combined action of activated materials to obtain higher density and lower sintering temperature. Dolomite refractories. In milling by a pulverizer, modification of the dolomite surface and internal structure with additives is also required to improve the slag resistance after sintering.