Hydration resistance of magnesia-calcium brick

Because magnesia calcium brick contains free CaO, in the process of storage and use of magnesia calcium brick, if exposed to external water will occur hydration, resulting in loose magnesia calcium brick structure, the use of performance decline, in serious cases will cause scrap. Therefore, improving the hydration resistance of magnesia-calcium brick is one of the main technical problems involved in the production and use of magnesia-calcium brick. Magnesia-carbon bric

The higher the free CaO content of magnesia-calcium brick, the worse the hydration resistance. Therefore, the hydration resistance of magnesia dolomite brick is better than that of dolomite brick. This is also one of the reasons why the use of magnesia dolomite bricks is more common than dolomite bricks. The ways to improve the hydration resistance of magnesia-calcium brick are as follows: firstly, reduce the free CaO content in magnesia-calcium brick as much as possible; The second is to avoid contact between magnesia-calcium brick and external water.

The content of CaO in magnesia-calcium brick is reduced and the content of MgO is increased, so that MgO in magnesia-calcium brick forms a continuous phase, free CaO is separated and wrapped by MgO. Add an appropriate amount of additives, such as ZrO2, TiO2, etc., to the ingredients of magnesia-calcium bricks, react with free CaO to form hydration resistant minerals, and wrap the free CaO.

Using high density synthetic magnesia calcium raw material, under the premise of meeting the high temperature performance of magnesia calcium brick, the synthetic magnesia calcium raw material contains a small amount of impurities, impurities react with CaO at high temperature to form hydration resistant minerals, but also promote the material sintering, improve the density of magnesia calcium brick.

When making bricks, the raw materials are dried and the bond is fully boiled to avoid bringing water into the brick. The produced magnesia-calcium brick is sealed and packaged in time to prevent contact with external moisture.

Avoid the contact between magnesia-calcium brick and water when laying the furnace lining, and bake and put into use in time after laying. During use, as far as possible to avoid a long shutdown. During the shutdown period, the lining should be baked to avoid hydration due to cooling and moisture absorption of the lining.