At the meeting, Professor Ye fangbao, Institute of high temperature materials, Zhengzhou University, Professor Wei Yaowu, School of materials and metallurgy, Wuhan University of science and technology, Professor Zhang Sanhua, chief expert of amorphous refractories of Luoyang Refractories Research Institute Co., Ltd., Dr. Li Zhigang, Zhengzhou Kexin furnace materials Co., Ltd., Dr. Bi Zhenyong, general manager of Henan Haiger high temperature materials Co., Ltd., and Heng were invited Mr. Shao Changbo, general manager of jiagaochun, made a special technical exchange on the research and development trend of alumina refractory raw materials and refractory technology, which was followed and reported by China Refractory window network. More than 80 enterprises and 170 people from all over Henan and surrounding provinces attended the meeting.

                                          Conference site

    The meeting was kicked off by Mr. Li Hongchao, sales manager of Higianthigh purity central and western regions, who introduced Higiant high purity executives to the guests attending the meeting. Mr. Wang Yongting, sales director, warmly welcomed the guests on behalf of Higiant Gaochun. At the same time, he thanked the customers and friends who supported and accompanied Higiant Gaochun's growth.

         Mr. Wang Yongting, deputy general manager and marketing director of HigiantGaochun

    General manager Wang said that Higiant high purity technology exchange meeting has been held for three times, and the fourth session has returned to Gongyi, which is of great significance. In just four years, Higiant high purity has realized the listing of the new third board, and successively launched new products such as plate-shaped corundum, hydrated alumina and high-purity spinel for permeable brick core. The annual capacity of plate-shaped corundum and high-purity spinel has reached 50000 tons, the annual capacity of calcination and active α - alumina has reached 45000 tons, and the annual capacity of aluminum rich spinel powder has reached 5000 tons, with a total capacity of 100000 tons. While attaching importance to the development of domestic market, actively expanding foreign market, the sales volume in 2019 is expected to achieve a year-on-year growth of 50%, reaching 200 million yuan. With the increase of production capacity, continuous new products and substantial increase of sales, Higiant Gaochun's confidence in "persistence, pursuit of stability, quality for excellence, and creation of excellence" has been strengthened. It will give back the trust of users with high-quality and stable raw materials.
Next, university professors and enterprise senior engineers shared the research progress and test results of castable for iron trench and ladle. The meeting was presided over by Chen Zhiqiang, technical director of Higiant high purity Technology Co., Ltd.

Chen Zhiqiang, technical director of Higiant high purity Technology Co., Ltd. presided over the scene

    Mr. Zheng Daye shared "the influence of micro powder on the rheological behavior of pumping castable". He introduced the construction technology development of refractory castable, the characteristics of pumping castable, and mainly explained the rheological properties. By studying the rheological parameters of castable, we can accurately get the deformation and viscosity change of castable under the action of shear stress at different rates, truly evaluate the rheological behavior of castable in pumping pipeline, and have different rheological properties for development The castable has theoretical guidance and practical application significance.
    He used corundum castables and bauxite silicon carbide castables for rheological tests. It is found that the rheological behavior of castable is controlled by the properties of matrix, and the main component affecting the rheological behavior of matrix is micro powder. The rheological behavior of the two castables is Bingham fluid. At the same time, in order to realize pumping smoothly, it is necessary to control the rheological properties, and in order to avoid swelling fluid, the fluid type should also be controlled in the yield pseudoplastic fluid or Bingham fluid type.

     Professor Ye fangbao, Institute of high temperature materials, Zhengzhou University

   In the experiment, Mr. Ye also found some problems, and asked the raw material manufacturers to pay more attention to the particle size, particle size morphology, activity evaluation index, impurity content and type, quality stability of the micro powder. He conducted basic research on the surface characteristics of the micro powder and the dispersion effect of the composite powder.
   Mr. Wei of the University of martial arts showed the influence of the test method on the thermal shock stability of corundum castable and analyzed it. The performance of refractories to resist the rapid change of temperature without damage is called thermal shock stability or thermal shock resistance. The test method and test method of thermal shock stability are introduced in the report. Through the natural cooling, air cooling and water cooling tests of corundum castables after heating, the flexural strength, elastic modulus, pore size distribution and microstructure of the samples are compared and analyzed. It is suggested to test the thermal shock stability of corundum castables by heating air cooling cycle. The results show that the existence of microcracks of certain size is helpful to improve the thermal shock stability of the material.

  Professor Wei Yaowu, School of materials and metallurgy, Wuhan University of science and technology 
     The report presented by Professor Zhang of luonaiyuan is "the influence of spinel composition and addition amount on the properties of corundum spinel castable". He said that spinel has the advantages of high melting point, stable chemical properties, good slag resistance and small coefficient of thermal expansion, which has been widely used in shaped and amorphous refractories, such as skateboards, air permeable bricks, prefabricated blocks, ladle castables, etc. In order to understand the influence of spinel composition, solid solution and desolvention behavior on the properties of corundum based castables, 14 groups of experimental schemes of corundum based castables were designed. In the castables, a quantitative amount of corundum aggregate, cement, α - alumina micropowder were added, the amount of corundum micropowder and different grades of spinel micropowder (am70, am85, AM90) were adjusted After that, the cold and hot bending strength, microstructure and slag resistance of the castable were tested. The results showed that under the experimental conditions, the composition of three kinds of spinel added with fine powder had little effect on the properties of corundum based castable, but the effect of adding or not or adding proper amount was more significant.

Professor Zhang Sanhua, chief expert of amorphous refractories of Luoyang Refractories Research Institute Co., Ltd. of Sinosteel group

     Dr. Li Kexin of Zhengzhou explained the concept of refractory innovation. He believed that refractory innovation is based on the continuous improvement and improvement of existing products and processes. As a traditional Al2O3-SiC-C castable, it is not only an oxide non oxide composite material, inorganic organic composite material, self repairing intelligent material, nano composite material, gradient material, but also a functional material. It has excellent slag resistance, good thermal shock performance, and better mechanical properties. The combination methods mainly include ultra-low cement combination, no cement combination, and no silica fume cement Combination.

            Dr. Li Zhigang of Zhengzhou Kexin charge Co., Ltd

    The thermodynamic analysis and performance study of Al2O3-SiC-C castables with different bonding modes show that under the condition of carbon burial, the stability order of SiO2 containing oxides is quartz < mullite < calcium feldspar; under the condition of carbon burial, when the temperature is lower than 1431 ℃, the content of carbon and SiO2 in the castables increases due to the oxidation of Si and SiC in the materials by CO, and only when the temperature is higher than 1431 ℃, can SiC exist stably. SiO2 in the castable is not conducive to the structural stability of the material. At high temperature, SiO2 gas escapes, resulting in loose structure and unfavorable performance of the material. The cementless Al2O3-SiO2 bonding system is not suitable for Al2O3-SiC-C castable used at high temperature.
    The general report of hagelby is "a discussion on the composition and properties of the castable of Al ξ o ₃ - MgO". He pointed out in the report that the refractory for ladle faced new challenges, such as high requirements for safety and environmental protection, high labor intensity in masonry construction, shortage of workers, large fluctuations in raw material quality and price, energy conservation and consumption reduction, ladle expansion, thickness reduction of lining, and timely adjustment of technical scheme. The advantages and disadvantages of castables, prefabricated parts and magnesia carbon bricks were compared, and the thermal shock stability of alumina magnesia shaped refractory was emphasized The optimization experiment should take the practical application effect as the final evaluation standard. It is also proposed that the development of refractories from traditional mode to new mode, such as lightweight corundum, stress dissipation aggregate, new structural optimization additives and other new concepts, new ideas, new products are worthy of attention.

     Dr. Bi Zhenyong, general manager of Henan Hager high temperature materials Co., Ltd

   Higiant high purity Shao reviewed the company's development process for more than six years, as well as the current research and development of testing equipment and technical level. Since 2014, Higiant high purity has invested more than 8 million yuan to build an alumina based refractory material R & D center, with more than 40 sets of various testing instruments such as XRD, XRF, SEM, bet, etc., which can carry out online testing of raw materials, effectively control the stability of product quality, realize the R & D of alumina based refractory materials, carry out product application tests and help customers test and develop.

            Mr. Shao Changbo, chairman and general manager of Higiant high purity

     Next, Shao introduced the classification of calcined alumina powder and activated alumina powder in detail, as well as the role in refractories, and discussed the application of α - Al2O3 powder in iron channel castables and ladle castables. However, Higiant plate-like corundum is a pure Al2O3 raw material, which is composed of well-developed α - Al2O3 crystal without the addition of low melting point impurities such as B2O3 and MgO. The pores in the crystal can inhibit the crack growth, and the grain boundary between the crystal and the crystal can also buffer the thermal stress, which are beneficial to thermal shock resistance. The micro pores on the surface of plate-like corundum are beneficial to matrix sintering. It can improve the high temperature strength and erosion resistance of the castable when applied in the iron trench material; it can help to improve the wear resistance of the material when applied in the ceramic wear-resistant material, it can also help to improve the processing accuracy of the materials requiring mechanical grinding such as the sliding plate and the water nozzle, and it can also improve the thermal shock resistance of the material.
     As for the new high-purity magnesia alumina spinel am-78, the purity (Al2O3 + MgO) > 99.8%, the impurity content is low, the low melting matter is less, it is more heat-resistant, it does not contain the periclase phase, the crystal is large, the closed pore structure, the high temperature strength is high, the thermal shock stability is good, and the hydration resistance is strong. He also introduced the application of am-90 active spinel ultrafine powder developed by Higiant company ten years ago in large ladle castable and coating spraying, which can greatly improve the service life of ladle material.
In addition to the sharing of experts and high technology, the meeting also conducted on-site interactive exchanges, which made the participants fruitful. Higiant high purity also made more customers understand Higiant's plate-shaped corundum, spinel and alumina powder through this meeting. Through contact and communication with customers, Higiant high purity also understood customers' products and requirements for plate-shaped corundum, alumina powder and other raw materials, which laid a solid foundation for the perfection of Higiant high purity products and the research and development of new products.
    Higiant high purity will adhere to the professional attitude of "professional, attentive, single-minded, and strive for perfection", and make HENGJIA become a famous brand of aluminum oxide refractory materials at home and abroad, helping the high-quality development of refractory materials in China.