wanhaorefractory

  1.The slurry in the alkali-eroded alumina clinker kiln is mixed with a considerable amount of alkaline substances such as CaCO? and Na?CO?, which are soaked or adhered to the lining surface at high temperature and penetrate into it, in addition to their own chemical changes , and may also react with the lining to form a two-component tissue along the cross-sectional direction, destroying the tissue structure of the original lining, thereby reducing the strength of the lining. When the temperature or composition of the material changes greatly, the two phases separate and the lining peels off. It is easy to prove this point by analyzing and comparing the petrographic structure of the peeled block, the residual brick and the original brick. It can be seen from the alkali existence state of the preheating zone and the decomposition zone that these two working zones are most severely affected by alkali erosion, but the strength of the material itself at this stage is low...

  The outlet angle of submerged entry nozzle affects the kinetic energy loss of jet，then affects the flow behavior in the mold. A 1∶4 scale water model of slab mold was built. The influence of 0° and +5° nozzles on the flow behavior in wide slab casting mold was studied using particle image velocimetry under the condition that pulling rate was 0.425 m/min and nozzle immersion depth was 40 mm. The results show that there is a big difference in jet morphology between 0° and +5° nozzle. When the angle is 0°，the jet flow is relatively concentrated and spread slowly，it will spread to the wide surface in the direction of thickness when it reaches the narrow surface. However，at +5°，the jet has a process of upward impact and back again，and the expansion range of jet is larger than that of the 0° nozzle. This will make more jets impact the wide surface before reach the narrow front(which can reach the wide surface within 0.3 s). It means that the molten steel scours dendrite...

   When  MgO-C bricks  are used for refining ladle furnaces and ladles, they are mainly used in headroom and slag lines. According to the operating conditions, the refractory materials used in these parts must have high temperature resistance, thermal shock resistance, and resistance to mechanical corrosion caused by slag erosion. So in the past, these parts used magnesia-chromium refractory materials, but considering that chromium pollutes the environment, its consumption has been reduced, and now  magnesia-carbon bricks  are used. Since the magnesia-carbon bricks in the new ladle will be severely damaged during the preheating process, the loose decarburized layer can reach 30-60mm thick. This layer is washed away during the injection of molten steel, bringing the magnesia grains into the slag. Obviously, preventing the carbon in the magnesia carbon bricks from being burned out during preheating is one of the important steps to improve the se...