NOVEL REFRACTORY MATERIALS FOR HIGH ALKALI, HIGH TEMPERATURE ENVIRONMENTS

Hemrick, James Gordon ; Smith, Jeffrey D ; O' ; Hara, Kelley ; Rodrigues-Schroer, Angela ; Colavito,

Oak Ridge National Laboratory

关键词: Coal Gasification;    Spent Liquors;    Kilns;    01 Coal, Lignite, And Peat;    36 Materials Science;   

DOI  :  10.2172/1049095
RP-ID  :  ORNL/TM-2012/245
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  1049095

美国|英语

来源: UNT Digital Library

【 摘 要 】

A project was led by Oak Ridge National Laboratory (ORNL) in collaboration with a research team comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al 2O3, MgAl2O4, or other similar spinel structured or alumina-based unshaped refractory compositions (castables, gunnables, shotcretes, etc.) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, high-alkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. Both practical refractory development experience and computer modeling techniques were used to aid in the design of this new family of materials. The newly developed materials were expected to offer alternative material choices for high-temperature, high-alkali environments that were capable of operating at higher temperatures (goal of increasing operating temperature by 100-200oC depending on process) or for longer periods of time (goal of twice the life span of current materials or next process determined service increment). This would lead to less process down time, greater energy efficiency for associated manufacturing processes (more heat kept in process), and materials that could be installed/repaired in a more efficient manner. The overall project goal was a 5% improvement in energy efficiency (brought about through a 20% improvement in thermal efficiency) resulting in a savings of 3.7 TBtu/yr (7.2 billion ft3 natural gas) by the year 2030. Additionally, new application techniques and systems were developed as part of this project to optimize the installation of this new family of refractory materials to maximize the properties of installed linings and to facilitate nuances such as hot installation and repair. Under this project, seven new shotcrete materials were developed for both primary and repair applications in aluminum, black liquor, coal gasification, and lime kiln environments. Developed materials were based on alumino-silicate, magnesia, and spinel forming systems. One of the developed materials was an insulating shotcrete to be used behind the high conductivity spinel linings developed under this project. Fundamental research work was carried out at MS&T throughout the life of the project to provide support for the development and production of the experimental refractory materials being developed. Work was also ongoing at ORNL and MS&T through the duration of the project on the measurement and characterization of key refractory properties as identified during year one of the project. Both materials currently being used in the industrial processes as identified and supplied by the industrial partners of this project and new materials being provided and developed by MINTEQ were evaluated as necessary. Additionally, energy savings estimates based on measured properties of the experimentally developed refractory systems from this project were made at MINTEQ to validate the energy savings estimates originally proposed for the project. As another part of the project, on-line inspection and hot repair techniques were considered. It was determined that although repair materials were successfully developed under this project for aluminum, black liquor, and coal gasification systems which enable hot repair, there was only minor interest from industry in implementing these materials. On-line inspection techniques were also identified under this project which are currently used in the steel industry, but implementation of these techniques in applications such as black liquor and coal gasification where higher temperatures and tighter access clearances exist proved difficult due to cost considerations. Therefore, on-line inspection was not further pursued under this project. Information from data collected during this and previous DOE projects was inputted into a refractory database housed at a public site (http://extwebapps.ornl.gov/crpd/Default.aspx). This database was initially populated with over twenty five refractory systems. Industrial trials of the insulating shotcrete (INSULSHOT FH) and the material for use in aluminum rotary furnaces (ROTOSHOT AL) developed under this project were performed validating the commercial potential of these materials. Additionally, the magnesia-rich spinel formulation (FAST FIRE MG-SP SHOT) for use in black liquor and lime kiln/cement applications was commercially released by MINTEQ. Industrial trials were monitored through the end of the project...