Function and performance of blast furnace taphole clay

Small blast furnaces are generally provided with an iron outlet and 2 ~ 3 slag outlet, large and medium-sized blast furnaces have 2 ~ 4 iron outlet and 1 ~ 3 slag outlet. The taphole clay used to plug the iron opening is squeezed in by a mud gun, so it is also called gun mud. The taphole clay used in blast furnace should have the following properties:

1) good plasticity and cohesiveness, easy to squeeze into and fill gaps and cracks: 2) suitable porosity, easy to discharge moisture when dry. 3) Shrink the volume at high temperature to avoid cracks. 4) Good sintering performance, high strength, erosion resistance and erosion resistance. 5) Easy to open, to ensure that molten iron and slag can flow out at a uniform speed. The taphole clay (mainly water taphole clay) used in small and medium blast furnaces is mainly made of clay clinker particles, coke powder and asphalt. The taphole clay used in large and medium-sized blast furnaces (mainly anhydrous taphole clay) is generally made of high aluminum material, and added with additional materials such as silicon carbide and carbon, so as to stabilize the depth of the iron outlet.

The taphole clay used in blast furnace is a functional refractory material. Function of taphole clay in iron drawing operation in front of blast furnace

As the valve, when the iron needs to be out, the iron hole will be opened. After the iron is out, the iron hole can be plugged in time, and the iron time should be ensured.

Marchia value is an important physical index of taphole clay, and high quality taphole clay must have good performance.

Easy to open: when the iron outlet needs iron, the mud in the iron outlet hole can be easily drilled through, timely iron, ensure the smooth operation of the blast furnace before the furnace, reduce the labor intensity before the furnace;

Easy to block: when the iron outlet is finished, it can block the iron outlet in a short time, and ensure enough mud to maintain a stable iron depth; The variation of iron hole depth causes the fluctuation of iron output. Too deep iron mouth is not conducive to opening iron mouth and iron out point, prolong the iron out time, and waste plugging mud; If the iron mouth is too shallow, it is easy to produce iron accidents, and produce unclean and uneven slag iron, which has a great influence on the stable operation of the furnace. If the iron mouth is too shallow for a long time, it is easy to lead to the furnace cylinder burning accident, which seriously affects the long life of the blast furnace.

Good adhesion. The new gun mud driven into the iron hole should have good adhesion with the old gun mud in the hole, so that the new and old mud form a whole, to prevent the existence of cracks, resulting in iron infiltration, slag infiltration, affecting the iron and the occurrence of safety accidents before the furnace;

Good sinter property. It is required that the taphole clay in the hole of the iron outlet can reach different degrees of sintering in the three temperature stages of low temperature, medium temperature and high temperature, so as to plug the iron outlet in time and form a mud bag of sufficient size in the hearth to protect the lining brick of the cylinder.

It has good scour resistance and erosion resistance, and the iron opening aperture does not expand sharply, so as to ensure that the iron time is 150~180 minutes/time, and reduce the number of iron out before the furnace. The reasonable number of iron out should be maintained at 8~10 times/day. Reduce the labor intensity in front of the furnace, reduce the material consumption in front of the furnace, so as to reduce the cost.