2015-03-23 Refractory Window

With the increasing emphasis on energy conservation and consumption reduction in the steel industry, refractory raw materials and materials are developing towards lightweight and low thermal conductivity. As a result, the upgraded product of "sintered corundum" - energy-saving lightweight microporous corundum - has emerged.

In January 2015, Jiangsu Jingxin High Temperature Materials Co., Ltd., a large domestic sintered synthetic refractory raw material enterprise, received news that Jiangsu Jingxin had achieved a breakthrough in upgrading from sintered corundum to microporous corundum. Currently, it has successfully produced more than 400 tons of microporous corundum and officially entered the stage of mass production. Zhejiang Zili Alumina Material Technology Co., Ltd., a rising star in alumina production, organized a project appraisal meeting for the Zhejiang Province New Product Trial Production Plan, stating that it has successfully trial produced microporous (lightweight) corundum.

Micro porous corundum is mainly made from industrial alumina, aluminum hydroxide, and α - Al2O3 micro powder, with appropriate additives added, and rapidly fired in a high-temperature vertical kiln. The product has the characteristics of low apparent porosity, high strength, good thermal shock resistance, and high refractoriness. Compared with ordinary sintered corundum, the strength and corrosion resistance are basically equivalent. By increasing the internal closed micro pores, the thermal conductivity and structural thermal stress of the material are reduced, and the insulation and thermal shock resistance of the material are improved. It can be applied to partially or completely replace ordinary sintered corundum in refractory products such as steel bag walls and bottom castables, prefabricated parts, and seat bricks. The strength and corrosion resistance of refractory products produced using microporous corundum will not be reduced, and they will also have better thermal shock resistance, low thermal conductivity, and energy-saving insulation performance.

How should sintered corundum enterprises respond to the emergence of microporous corundum?

Since the trial production of sintered corundum by Shandong Aluminum Industry in 1995, domestically produced sintered corundum in China has undergone 20 years of development. The production process is relatively mature and the quality is relatively stable. It is widely used in the production of high-performance refractory materials for steelmaking, such as sliding nozzles, sliding plates, permeable bricks, castables, and prefabricated parts. As of the end of 2014, the production capacity of sintered corundum had exceeded 350000 tons, with an output of around 250000 tons. Enterprises with advantages in alumina resources were still considering launching sintered corundum projects. Refractory product enterprises with large amounts of sintered corundum also planned to build new production lines or acquire existing sintered corundum enterprises to achieve cost reduction goals. The overcapacity and self-sufficient development of product enterprises have brought pressure to raw material enterprises that produce and sell sintered corundum. They not only have to face price wars from competitors, but also need to be wary of white corundum making a comeback at low prices, and new micro porous corundum making efforts to seize the market. They must also face the decline in product prices and the compression of profit margins. Therefore, the editor believes that the challenge facing sintered corundum enterprises in 2015 is how to reduce production costs, maintain price advantages, and maintain existing market share while stabilizing the performance of sintered corundum.

Although microporous corundum can theoretically replace sintered corundum, in the sluggish situation of the refractory industry chain market, it is still difficult for companies accustomed to using sintered corundum to choose high priced new faces of microporous corundum. Therefore, it is impossible for microporous corundum to completely replace sintered corundum in the short term, and the market position of sintered corundum cannot be shaken. However, companies can face it calmly and also need to not reject microporous corundum products or blindly launch microporous corundum projects, after all, lightweight development is the current trend of material development.

It is reported that the microporous corundum produced by Jiangsu Jingxin has been successfully applied in ladle casting material manufacturers, but due to its higher price compared to sintered corundum, the product has not yet been widely recognized, resulting in a slightly slow development of the microporous corundum market. However, Jiangsu Jingxin has clearly stated that the second phase of its "three-step" strategy for mass production is beginning, and the third phase is to promote cooperation in a wider range of fields. Through Jiangsu Jingxin's experience in domestically producing and promoting sintered corundum and the momentum of Zhejiang Zili Alumina Material Technology Co., Ltd. in producing and actually applying sintered corundum and developing and applying microporous corundum, we have reason to believe that the future market for microporous corundum is promising.