Low cement cast-able

Low Cement Cast-able

Low cement cast-able is a new type of castable with little binding dose. The key is to use no more than 1 μ M ultrafine particles. Its heat shock resistance, slag resistance and corrosion resistance are significantly improved, which is higher than that of similar refractory bricks. Ultra Low Cement Castables and cement free castables can be prepared by further reducing the binder content.

Low cement castable is a high-tech refractory developed on ordinary castable by using rheological principle, closest packing theory and ultra-fine powder technology. It has the characteristics of low porosity, small pore size, large density, good volume stability, high strength and small amount of water. It overcomes the characteristics that the strength of ordinary castable decreases significantly at 800 ~ 1200 ℃, and increases with the increase of temperature. In this way, the thermal shock of furnace body can be more than doubled.

Application of low cement castable

(1) Anchor nail welding. Use the pistol welding gun to clamp the anchor nails with the supporting anchor nail chuck, and weld the water-cooled beam (column) according to the design spacing.

(2) Ceramic fiber felt binding and surface treatment. Wrap the pre processed block ceramic fiber felt on the corresponding water-cooling beam (column), wrap the ceramic fiber felt tightly on the water-cooling beam (column) with Z2 galvanized iron wire, and then spray hardener on the surface of the ceramic fiber felt. The pouring construction can be carried out only after it is dried and hardened to form a hard shell on the felt surface.

(3) Formwork installation. In order to ensure the shape of lining wall after pouring and the fumigation and reuse of formwork, 4 mm thick steel plate is used to make shaped steel formwork. The steel formwork shall be installed from bottom to top, and the lower end of the later installed formwork shall be clamped on the poured lining wall.

(4) Mixing of Low Cement Castables. Forced mixer must be used for mixing, clean water shall be used, and the water temperature shall be 10 ~ 25 ℃; Ingredients and water shall be added in strict accordance with the mix proportion given in the material operation manual; In order to overcome the uneven particle size distribution of dry aggregate during transportation; It shall be dry mixed for 1 min and then mixed with water for 4 ~ 5 min.

(5) Pouring. The mixed castables are quickly transported to the pouring site, and the castables are poured into the mold with a small shovel and a special lower hopper. When pouring the beam, blanking shall be carried out from one side of the formwork to prevent voids at the lower part of the beam. During blanking, the wrapped ceramic fiber felt shall be prevented from breaking and falling off. After the material is filled, start the vibrator, the material surface sinks during vibration, and add material in time. When the pouring material surface no longer sinks or there is no bubble escaping on the surface, the vibration can be stopped. The vibration time is generally 2 min.

After the column castable vibrates, the surface shall not be repaired. After the beam castable vibrates, it shall be scraped and formed with an iron trowel before the initial setting of the castable, so that the section of the castable lining wall on the upper part of the beam meets the design requirements.

(6) Formwork removal and repair: when the temperature in the furnace is 10 ~ 25 ℃, the formwork can be removed 8 hours after pouring, and the castable can be cured naturally after formwork removal. The pouring quality shall be inspected in time. General defects shall not be treated, but important parts and major problems shall be repaired to make the lining wall meet the production process requirements.