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.

Refractory material for lime kiln

There are many kinds of main shaft kiln, lime kiln, rotary kiln and annular kiln etc… Most of the countries with the shaft kiln production of lime; the lime requirement is large, using rotary kiln.

Lime shaft kiln feed around the mouth and pre tropical lining of the body temperature is low, mainly due to mechanical impact material and wear, can choose the dense clay brick masonry. Calcined lime kiln lining body, subjected to chemical erosion wear, material flow and CaO at high temperature, rapid damage. For the small shaft kiln, generally used in low porosity and high alumina brick and illuminate brick; for large shaft adopt magnesia chrome brick, magnesia brick, magnesia spinel brick and brick for burning zone lining of the body.

Lime shaft kiln cooling zone and a lining material around the mouth, using the temperature is relatively low; damage reason is lime wear and alternating hot and cold induced temperature difference, the site selection of high – strength of clay brick masonry.

The laying of firebrick in furnace

Drum type heating furnace is mainly composed of a cylinder, head, tube, pipe, oil (water) distribution pipe, smoke box, a chimney, saddle and the interface tube etc… The combustion of the fuel in the furnace, forming high temperature flue gas and release the heat, high temperature flue gas heat generated by a fire tube or pipe to heat conduction, convection, radiation, convection, the heat is transferred to the medium in the furnace, the temperature reached the process demand.

The heating furnace in the burner side fire tube entrance laying 1.2 ~ 2.4m long refractory brick, the fuel burns, ceramic fiber blanket generates a lot of heat in the refractory brick refractory brick surface, heat transfers to the outside, causing the distance refractory brick recent fire tube heat intensity is too high, local overheating, oxidation, axial, radial deflection indentation deformation.

Transfer station is widely used at present, self discharge process, silt into the furnace from the water discharge pipe, the heating medium convection heating furnace of sediment, stirring constantly, and finally fell on top of the fire tube and smoke pipe.

Can be found in dredging, heating furnace overhaul, the heating furnace tube sediment thickness more than 150mm, especially in the high temperature zone of the fire tube (refractory bricks in 100 ~ 500mm of maximum sediment thickness). Under such circumstances, is bound to cause loss, heat transfer efficiency of the heating furnace of local overheating, drum kits, perforation may happen at any time.

The innovative development of refractory material

In high production, refractory material  based on the characteristics of heat resistance, plays an irreplaceable role in high temperature industrial development. It is widely used in metallurgy, petroleum, chemical, ceramics, glass and other industries, and provides convenience for the development of industry. Therefore, refractory products market is the vast.

A general increase in 2014 production of refractory products. One led by Liaoning, reached 4583429 tons, achieved the growth of 5.27%. But the yield at least Xinjiang, although 1-2 monthly production is 2000 tons, but also the growth of 21.07%, than in the past has been greatly improved.

Production and processing of refractory material production,because of the need for natural resources as the foundation, so the regional demand is very high.Refractories enterprises are mostly distributed in the regions of China East China and southwest, central China area almost no. Dispersive inter industry.

As refractory materials have certain market products, in order to have a better development in the future road, while maintaining the original advantages at the same time, and constantly innovation, in innovation and development. New products from quality of original for energy saving, environmental protection, many varieties, high profit, so as to increase their competitiveness in the market is refractory products remain invincible in the market.