Production technology: high purity synthetic dolomite sand and high purity magnesia as the main raw materials, while adding a certain amount of binder, through mixing and refining and made. Main application: used for ramming the bottom of AC and DC electric furnace without adding any binder and moisture. Usage: the use of the product is simple, that is, in the bottom of the furnace spread 100-150mm thick bottom material, after vibrating and compacting, the surface scraping once, and then the next auxiliary material, and so on. After the completion of the furnace bottom ramming material construction, a layer of thin steel plate is laid on its surface to prevent the surface from being damaged when it is loaded with scrap iron or molten iron.