Application of mullite materials in rotary kiln

Mullite aluminum silicate formation at high temperature minerals, the magnetization roasting rotary kiln lower process temperature, process characteristics of resistance, corrosion resistance, thermal shock resistance, mullite SiC composite prefabricated brick with mullite materials and silicon carbide material composition and mullite SiC castable method of composite masonry, at the same time refractory materials at high temperature with different proportions, to improve the thermal stability of refractory materials, delaying the ring material erosion of refractories and destructive effect, slow ring phenomenon, obtains a good application effect.

Masonry of refractory materials has also been a corresponding improvement. The composite precast slabs by anchor is welded and fixed on the kiln body, between two rows of brick layer with light castable and wear resistant pouring material filling, ensure the integrity, stability and thermal insulation refractory. In building process, in order to prevent the kiln rotary kiln in emphasis, built after four rows of prefabricated brick, turn to the top and then laying four lines. After the completion, in turn rotary masonry.

Through the above method, to ease the interaction of refractory materials and materials, delaying ring phenomenon. And the use of masonry composite prefabricated brick and abrasion resistant castable refractory material to strengthen the strength, processing node ring for refractory material damage, repair cycle is short. Through the practice, refractory maintenance cycle from 2 to March was extended to 1 year, improve the rotary kiln operating rate, with significant economic benefits.

The operation of corundum castable

We usually do not know how many of corundum castable understand, then give you some tips and tricks, discuss with you today is the knowledge of its sample. The following summarizes the four o’clock related content, you can carefully read this:

1. When the sample production and maintenance, the ambient temperature is 20 ℃ ± 1 ℃. Using 40mm × 40mm × 160mm mold making.
2. When the ingredients must first aggregate, (A + B) and part of the cement binder Stir respectively, and then press the 93:7 (A + B): 0.15 Weigh aggregates, cement binder. The weighed aggregates, cement and additives used in the experiment into the dry mix mortar mixer for 2-3 minutes, then add clean tap water, add water to the total weight of material 4.8 to 6% (press the lower water, in pourable performance guarantee provided to minimize the amount of water), stir 3 to 5 minutes until construction material has good plasticity, can be cast.
3. Good material into the wet mix tryout, on the vibration table to make it sufficiently dense vibration.
4. Forming complete specimen placed 20 ℃ environment conservation with mold release after 36 ~ 48h, after stripping the sample before drying treatment after 48 hours and then the Nature Conservancy.

These are the relevant content corundum castable sample operation, we can refer to, and I hope to help you understand the product. Today’s content introduced here, want to know more you can continue to focus on our product knowledge.

The relationship between wear resistance of refractory bricks and temperature

What is the relationship between the abrasion resistance of refractory brick and temperature, so here we briefly introduce:

Some materials such as silicon aluminum refractory brick, it is generally believed that under certain temperature (as in the 700 ~ 900 ℃ within elastic range), the higher the temperature wear resistance is low, can be considered as the temperature is increased with the increase of the elastic modulus, wear resistance decrease. When the temperature increased, reaching a maximum of elastic modulus, with lower elastic modulus, wear resistance increase instead. Such as aluminum silicate refractory brick in 1200 ～ 1350 ℃, the wear resistance even better than at room temperature, when the temperature is further increased, up to 1400 ℃ + for refractory brick in liquid phase viscosity decreases sharply decreased, wear resistance. Some brick such as chrome quality products, with the temperature increasing, the wear resistance increased.

Why the carbon containing refractories in Nickel Converter use effect is not good

Due to the poor wettability of molten slag and graphite, graphite to refractory oxides can greatly reduce the infiltration depth of slag refractory material, thereby reducing the thermal spalling and flaking refractories.Therefore, in the iron and steel industry especially some intermittent production equipment such as hot metal pretreatment tank (or bucket), oxygen converter, electric furnace, ladle, extensive use of carbon containing refractories, and achieved good results. Naturally want to carbon containing refractories used in copper, nickel converter, but the effect is not ideal. The former Soviet Union, Japan and China have in copper or Nickel Converter tried MgO – C, C, but the effect is not ideal.

Why the carbon containing refractories in the iron and steel industry especially the effect of oxygen converter steelmaking is very good, but in the smelting of copper, nickel converter is not ideal?

Metal melt the iron and steel industry is the Fe.c melt. The blast furnace gas contains large amounts of CO, carbon in liquid iron at or near saturation; natural, blast furnace, hot metal pretreatment tank available carbon and carbon containing material. The important task of oxygen converter steelmaking is to reduce the carbon in liquid iron, steel will precipitate a large number of CO gases, in iron making, converter, and oxygen pressure is very low.

Copper or nickel converter blowing to the matte or ice nickel (nickel matte, ice is Cu – Fe – S or Ni – Fe-s sulfide melt) FeS oxidation in the melt of FeO, into the molten slag.

As long as the partial pressure of CO is less than CO equilibrium partial pressure 5.02 × 105kPa, carbon containing refractories in carbon will be oxidized. While copper, nickel converter, CO partial pressure is small, far more than the CO equilibrium partial pressure 5.02 × 105kPa much smaller; thus in refractories containing carbon carbon, oxidation tendency is very large, it is easy to be oxidized. So the copper or Nickel Converter with carbon containing refractory lining, the use effect is not ideal.