Making magnesite roof refractories with additions of fused spinel

Conclusions The Nikitov Dolomite Combine has produced an industrial batch of magnesite — spinel roof products containing fused spinel in the batch. The experimental refractories have very high quality factors.Testing of these products in the roof of a large open-hearth furnace with intensive oxygen blow in the bath showed that their resistance is 19% higher than the resistance of roofs made from periclase — spinel brick in identical furnaces at the Krivoi Rog Metallurgical Factory (with a simultaneous increase in output of 3.1%)Translated from Ogneupory, No. 4, pp. 1–6, April, 1971.     

Magnesia roof refractories with fused spinel in the batch

Conclusions Dense highly fired roof refractories based on sintered magnesite powder and electrofused aluminomagnesia spinel are characterized by high volume constancy and a 30–50% lower wear compared with ordinary periclase — spinel products in comparative tests in the roofs of 600 ton open-hearth furnaces working with the use of oxygen.The wear of magnesite — spinel refractories containing 20, 30, and 40% electrofused spinel in the batch during service in the roofs of open-hearth furnaces occurs by fusion.Translated from Ogneupory, No. 1, pp. 24–28, January, 1971.     

Testing unfired volume-constant magnesite-chromite products in open hearth roofs

Conclusions Tests in the main roof of a 160-ton open-hearth furnace showed that the wear of unfired volume-constant magnesite-chromite products on average is the same as that of fired products MKhS worked in the same section of the roof. The minimum wear is shown by unfired products based on fused magnesite.The mechanism of the wear in unfired and fired magnesite-chromite products is basically the same.Translated from Ogneupory, No. 4, pp. 29–34, April, 1969.     

Magnesite — Spinel roof refractories from fused spinel

Refractories and Industrial Ceramics - The production technology for high-quality fused-spinel brick was developed under industrial conditions. Extensive industrial-scale tests demonstrated the...     

Service of forsterite refractories in regenerator roofs of open-hearth furnaces

Conclusions The Panteleimonov Refractories Plant produced a large industrial batch of forsterite roof brick for the lower structure of open-hearth furnaces. Tests carried out at the Donetsk Metallurgical Factory showed that it is desirable to use these forsterite refractories: the life of the regenerator roofs was four campaigns in the main roof with an adequately large residual thickness.Investigations established that the changes in the forsterite brick during service in the roof of regenerators are similar to the changes in bricks during service in other structural elements, but the destruction processes occur much more slowly.Translated from Ogneupory, No. 8, pp. 31–38, August, 1968.     

“AGING” of aluminomagnesia spinel ceramics

Refractories and Industrial Ceramics -     

Obtaining fused magnesia-alumina spinel and using it to produce magnesite-spinel roof refractories

Conclusions A method was developed for producing fused spinel which, when used in place of chromite as a component of the charge for basic refractories, yields roof products characterized by enhanced refractoriness under load, and also by low creep at elevated temperatures. This ensures high factors for the other properties. The preliminary testing of the refractories in the roofs of electric-steel melting furnaces demonstrated an increase in their wear resistance by 26–33% compared with the resistance of the currently supplied periclase-spinel refractories, which are used normally in these conditions.Translated from Ogneupory, No. 4, pp. 12–17, April, 1973.     

平炉精炼包冶炼工艺与耐火材料的应用

以平炉用精炼包冶炼工艺参数为依据，分析了ＬＦ精炼包渣线用镁炭砖蚀损的主要因素；提出改进镁炭砖用结合剂、添加高活性的合金粉、提高镁砂的ＣａＯ／ＳｉＯ２比和加入合成原料等措施，提高镁炭砖的抗氧化性和抗法侵蚀性能，从而满足了平炉用精炼包冶炼工艺用耐火材料的要求。     

Service of fused periclase refractories in linings of converter steel discharge holes

Conclusions Periclase and periclase-spinel blocks for lining the discharge apertures of steel melting converters made on the basis of fused periclase, in conditions at the Chelyabinsk Metallurgical Plant, have a resistance of 164–214 heats.The maximum wear resistance is possessed by periclase-spinel blocks made on the basis of fused periclase which is confirmed by the minimum wear during the heat (despite the relatively high initial porosity of the products), the number of thermal cracks, the extent of the working zone, and also the minimum quantity of fusible new formations in this zone.Important significance, in order to guarantee sufficient service, is attached to the rational selection of the diameter of the channel in the blocks. In conditions at the Chelyabinsk Plant it is desirable to try blocks with a channel diameter of 140 mm.Further increases in the resistance of periclase and periclase-spinel blocks, made on the basis of fused periclase, to the action of liquid and gaseous reagents of the melt should be achieved by improving the chemical and phase compositions and structure (for example, reducing the quantity and size of the pores).Translated from Ogneupory, No. 2, pp. 30–37, February, 1973.