Fused Cast Refractories for Steel Mills

DF Refratek is fully dedicated to manufacturing high quality fused cast refractories and providing innovative refractory service and solutions to glass,iron & steel, aluminum, petrochemical or wear resistant applications.

Catering to customers' requirements of high quality fused cast refractories on a continuous basis for iron & steel industry, DF Refratek promote 3 kinds of different quality fused cast refractory blocks for iron & steel industry: Fused cast alpha alumina block,fused cast mullite block and fused cast alpha beta alumina block。

Our strict quality and control standards enable us to meet even the highest specification requirements due to our competence in cutting, milling, grinding and finishing, even with large dimensions or special shapes, ensures compliance with tight tolerances.

1.Fused cast alpha alumina block ---DF-A---higher cost with best performance

DF-A has been successfully used as skid rails as well as soaking zone bottom of heavy duty pusher-type furnaces reheating ingots due to its excellent abrasion resistance.  It is available in many shapes & sized, and is produced with and without casting voids.

Typical Application:

• Walking beam furnace
• lSoaking pit furnace
• Pusher furnace

Attention:

• The block is a rigid material by nature containing some glassy phase.Impact of the blocks against each other should be avoided during the process of moving on rollers and turning over the edges and corners.Otherwise it is easily to split off.
• The blocks shall be kept in a dry, covered place. Water absorbed by the shrinkage cavity and the open pores may cause blocks to shatter when heated up or to burst if exposed to frost.
• The temperature of fused cast rails or bottom should not change more quickly than 60 °C / hour,preferably 40-50 °C / hour
• There are three phases when heating up the furnaces int iron and steel industry

1.drying
2.pre-heating
3.heating to the operating temperature.
The length of each phase is subject to the quality of the refractory material, their expansion and the thickness of              the furnace wall. Depending on the thickness of mortar or ramming mass, the prepared furnace bottom should                  be dried.

• When the temperature of 600 ℃ is reached, the heating up is continued with the main burners instead of the auxiliary ones at a constant rate of max. 60℃/h. It is imperative to avoid local overheatings. Fused cast materials should not be exposed to jet flame, and also the flow in of cold air should be avoid.

• When scale removal is necessary, the furnace should be cooled down below 800℃. Rapid cooling with compressed air or water spray may cause the fused cast blocks to shatter. Scraping slabs or hand tools are generally used for scaling.

2.Fused Cast Mullite Skid Rail Block  --- DF-SM----Cost & Effectiveness

Due to the extremely high resistance of  DF-SM against mechanical wear and its dense structure,fused cast mullite block is well suitable for the hearths and skid rails of preheating and pusher furnaces in the steel industry.

It is available in many shapes & sized, and is produced with and without casting voids.

Typical Application:

• Slab,Billet and Ingot pusher furnace
• Soaking pit furnace
• Walking bean furnace
• Preheating furnace or Reheating furnace

Recommendations for start up

• The recommended heating up rate of the hearth or the furnace should not exceed 50 °C / hour.
• At operational furnace temperatures not lower than 800 °C blooms, billets or slabs can be pushed onto a hearth lined with fusion cast refractory blocks.
• If it is necessary to lower the operational temperature of the furnace during the weekends or holidays, the furnace temperature shall not be decreased below 700 ° C.
• During reheating of the furnace the heating rate of the recommended 50 °C / hour should not be exceeded.

3.Fused Cast Alpha-Beta Alumina Refractory ---DF-M

Fused Cast Alpha-Beta Alumina(DF-M) is a fusion cast alumina refractory with about 45% alpha,53% beta alumina and a minor amount of glass phase.It provides excellent corrosion resistance and low defect potential in the conditioning or refining end of a glass melting furnace.Also it is selected for use in metal reduction cells due to its corrosion resistance and in skid rails application in a steel mill due to its excellent abrasion resistance.What is more, it is the primary solution for crowns and superstructure in oxy-fuel fired glass melting furnaces.

It is available in many shapes & sized, and is produced with and without casting voids.

Typical Applications:

• Glass Furnace:Paving,Refiner Sidewalls,Channels and Canals

• Oxy-fuel Combustion Atmosphere:Crown,Superstructure

• Magnesium and Titanium Reduction Cells

• Skid Rails of Steel Reheating Furnace