It is one kind of the Marvels top products as well as the traditional advantage. We have many patents for this kind of products. We have been producing them for more than 50 years as the founder of it in China. It has excellent resistance to slag attack, over temperature damage, vacuum attack, oxidation reduction and abrasion. It is widely used in critical parts of metal smelting furnace. Up to now, it is the best choice as working lining of smelter which adopts to different operation situations of vacuum, different slag PH value and strong oxidation. For example, it is used as working ling, and at location such as hot spot, slag, tuyere and flushing of various high-quality refining furnaces (RH or DH degasser, VOD, AOD, and ultra-high-power electric furnace), large non-ferrous smelting furnaces (such as flash furnace, convertor, anode furnace and Caldo furnace).
After salt impregnation, the physical and chemical properties are enhanced and the performance improves a lot. The apparent porosity will be decreased to about 5.0%, while the bulk density and the cold crushing strength will increase by about 0.05g/cm3 and 30MPa, respectively.
It is mainly made from fused mag-chrome, magnesia and chrome ore, pressed under high pressure and burnt at ultra-high temperature. Based on different raw material, it is divided into three types: Re-bonded Mag-chromite (FMK), Direct Bonded Mag-chromite (DMK) and Semi-rebonded Mag-chromite (SMK).
(1) Re-bonded Mag-chromite Brick (KROMAG FMK)
Made of fused magnesia chromite, it is produced by ultra-high temperature firing, with the properties of very good thermal shock stability, oxidation reduction resistance, thermal fatigue resistance, wear resistance and erosion resistance, especially with ultra-strong resistance to slag attack and vacuum damage. Under vacuum refining condition, or strong oxidation atmosphere, or ultra-high temperature liquid erosion, or high alkaline slag and frequent alkalinity changes in slag, they are proved to be the irreplaceable, the longest service life and the most economical furnace lining refractories. Therefore, they are widely used in the vacuum refining furnaces (e.g. RH Degasser, VOD degassing ladles), argon oxygen refining furnaces (e.g. AOD convertors), ultra-high power EAF furnaces, non-ferrous smelting big furnaces, or used at key parts of refining furnaces under very harsh conditions, e.g. working linings, hot spots, slag line zone, tuyere zone, erosion zone and easily damaged arts of big furnaces.
(2) Direct Bonded Mag-chromite Brick (KROMAG DMK)
Made of high purity magnesia and chrome concentrate, it is produced by high temperature firing, with properties of excellent thermal shock stability, slag attack resistance, thermal fatigues resistance, and vacuum damage resistance. In addition, they are resistant to oxidation reduction, comparatively better wear resistance and erosion resistance. Under vacuum refining conditions, or strong oxidation atmosphere, or ultra-high temperature liquid erosion, or high alkaline slag liquid and alkalinity changes in slag, the service life is the second after KROMAG FMK, but much more economical furnace lining refractories. It was widely used as working lining of furnace for steel, non-ferrous, chemical and paper making industries.
(3) Semi Rebonded Mag-chromite Brick (KROMAG SMK)
Made of fused magnesia chromite, sintered magnesia, chrome concentrate, it is produced under high temperature firing. It is one kind of transition products between re-bonded and direct bonded mag-chromite bricks. The thermal shock resistance is better than that of re-bonded mag-chromite brick, while the erosion resistance properties is better than the direct bonded mag-chromite bricks. It is widely used in nonferrous industry.