The basic composition of ordinary refractory ramming material is similar to that of refractory castables and plastics. The difference is that there are more refractory powders and less binder. Soft clay is usually added to increase the viscoplasticity and sinterability of the material. The critical particle size of the refractory aggregate is 10mm, and it is also useful for 5mm. The mass ratio of coarse and fine aggregate is 3:7 to 4:6. More fine aggregates, easy to knot and compact. The particle size composition of the refractory ramming material is generally 60%~65% of the refractory aggregate, and the refractory powder is 35%~40%, so that the bulk density can be obtained, and the lining after the beating is also bulky.
It should be pointed out that the refractory ramming material is applied more on the working layer of the steel drum and has achieved certain results. The refractory aggregate and powder are first-grade or super-grade bauxite clinker with a maximum particle size of 10 mm; when adding pyrophyllite or powder, it is called alumina wax ramming material, adding first-grade brick magnesia powder or metallurgical magnesia. When powder is used, it is called aluminum-magnesium ramming material, and the powder fineness is less than 0.09mm, accounting for more than 90%; using water glass solution with modulus 2.6 and density of 1.36g/cm3 or aluminum sulfate with density of 1.26g/cm3 The solution acts as a binder.
Practice has proved that the application of aluminum-magnesium refractory ramming material with more application and better effect on Shenggang drum has its composition. When the amount of magnesia powder is 9%~12%, sufficient magnesium-aluminum spinel can be formed, which has good slag resistance and long service life.
After the refractory ramming material is mixed, the volume density of the lining body is imitated, and the sample is prepared on a press. The sample was naturally cured for 3 days, dried and tested for performance.
Refractory ramming materials have also been applied in thermal equipment such as electric furnace tops, power frequency induction furnaces and refining equipment outside the furnace. Its varieties are high-aluminum phosphate and corundum-chromium-zirconium, water-glass aluminum-zirconium and magnesia-chromium, etc., which generally meet the requirements of the production process and have a high service life.
High-aluminum ramming material is made of Al2O3 88% alumina clinker as aggregate and powder, and more fused corundum powder is added to improve matrix performance, while adding Suzhou clay as plasticizer; magnesium aluminum The chrome ramming material is prepared from materials such as fused magnesia-chromium composite and aluminum-magnesium spinel. The aluminum zirconium ramming material is made of 85% alumina clinker with Al2O3 as refractory aggregate and powder, and ZirO2 is 64% zircon powder and Jiaozuo mud; magnesium-chromium refractory ramming material mix ratio; MgO91 The % brick masonry aggregate and powder are 55% and 15% respectively, the Cr2O347% chromite aggregate and powder are each 15%, and the water glass solution is 4% to 5%. The high-strength magnesia refractory ramming material uses 97% fused magnesia as the bone powder. The critical particle size is 5mm, the fourth-grade ingredients, the ratio of bone powder is between 7:3~6:4; the phosphate is used as the binder, the dosage is 2%~4%, plus the composite metal powder. When preparing the sample, the molding pressure is selected according to the specified bulk density. After the sample maintenance expires, the performance is checked, and the results are shown in Table 1-1. It can be seen from the table that the performance of this type of refractory ramming material is better, the compressive strength after burning is up to 123.2 MPa, the softening temperature of load is up to 1700 or more, and the lowest porosity is 13%.
Aluminate cement high alumina and corundum refractory ramming materials, periclase cement magnesia refractory ramming materials and phosphoric acid and phosphate refractory ramming materials have also been applied; for the convenience of users, refractory plants will be fire resistant The mashing material is added with a preservative and wet-kneaded evenly, and then sealed in a plastic bag, which can be stored for 3 to 6 months. There is still plasticity and can be beaten, and its performance is not significantly reduced. This type of ramming material, also known as plastic refractory ramming material.
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