This study aims to provide the basic knowledge for furnace refractory design by investigating refractory property changes occurred in a hydrogen atmosphere.Since refractory bricks are thermodynamically stable in a hyd...This study aims to provide the basic knowledge for furnace refractory design by investigating refractory property changes occurred in a hydrogen atmosphere.Since refractory bricks are thermodynamically stable in a hydrogen atmosphere at 1100°C,we tried to find out the minute changes.In this experiment,a refractory brick was prepared by andalusite,mullite chamotte,and clay as raw materials and heated to 1100°C in a 100%hydrogen atmosphere for 72 h.It was found that the strength of the brick was decreased and the color was changed to black by the reduction of impurities.And in addition,this study covered research on the slaking risk of MgO raw materials because the minimum temperature is expected to 400°C in fluidized reduction furnaces unlike shaft furnaces.展开更多
The use of materials from waste in buildings compensates for the lack of natural resources, solves the problem of waste management and provides an altern<span style="font-family:Verdana;">ative techniq...The use of materials from waste in buildings compensates for the lack of natural resources, solves the problem of waste management and provides an altern<span style="font-family:Verdana;">ative technique for protection of the environment. There are a lar</span><span style="font-family:Verdana;">ge number of industrial wastes that are used for full or partial replacement of raw materials in some construction materials. This review assesses mining waste in concrete as a substitute for aggregates and cement;in fired bricks as a substitute for soil;and in road backfill as a substitute for soil. This paper reviews some mining tailings, mine waste rocks and some slags obtained in the exploitation and/or processing of some ores including iron, gold, lead, phosphate, copper, coal, etc. Different physical properties, mechanical properties, chemical properties, heavy metal content, mineralogic composition, geotechnical properties and environmental properties (leaching test) of the mine wastes were examined. The physical, mechanical and environmental properties of the materials obtained by substitution of raw materials by mine waste were examined and compared to reference materials. Mining waste in cementitious materials offers good compressive strengths, while the porosity of the concrete and/or mortar is a factor influencing its toxicity. As for the waste in fired bricks, fired at a temperature of 900°</span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">C</span><span style="font-family:Verdana;"> or more, it offers convincing compressive and flexural strengths. The few research studies obtained on the use of mining waste in road embankments have shown that mining waste can be used as a sub-base layer and backfill as long as it is not toxic. In addition, several other mining wastes require special attention as substitutes for raw materials in construction materials, such as coltan, cobalt.</span></span></span></span>展开更多
基金supported by the Korea Planning & Evaluation Institute of Industrial Technology (KEIT)the Ministry of Trade, Industry & Energy (MOTIE, Korea) of the Republic of Korea (No. RS2023-00262421)
文摘This study aims to provide the basic knowledge for furnace refractory design by investigating refractory property changes occurred in a hydrogen atmosphere.Since refractory bricks are thermodynamically stable in a hydrogen atmosphere at 1100°C,we tried to find out the minute changes.In this experiment,a refractory brick was prepared by andalusite,mullite chamotte,and clay as raw materials and heated to 1100°C in a 100%hydrogen atmosphere for 72 h.It was found that the strength of the brick was decreased and the color was changed to black by the reduction of impurities.And in addition,this study covered research on the slaking risk of MgO raw materials because the minimum temperature is expected to 400°C in fluidized reduction furnaces unlike shaft furnaces.
文摘The use of materials from waste in buildings compensates for the lack of natural resources, solves the problem of waste management and provides an altern<span style="font-family:Verdana;">ative technique for protection of the environment. There are a lar</span><span style="font-family:Verdana;">ge number of industrial wastes that are used for full or partial replacement of raw materials in some construction materials. This review assesses mining waste in concrete as a substitute for aggregates and cement;in fired bricks as a substitute for soil;and in road backfill as a substitute for soil. This paper reviews some mining tailings, mine waste rocks and some slags obtained in the exploitation and/or processing of some ores including iron, gold, lead, phosphate, copper, coal, etc. Different physical properties, mechanical properties, chemical properties, heavy metal content, mineralogic composition, geotechnical properties and environmental properties (leaching test) of the mine wastes were examined. The physical, mechanical and environmental properties of the materials obtained by substitution of raw materials by mine waste were examined and compared to reference materials. Mining waste in cementitious materials offers good compressive strengths, while the porosity of the concrete and/or mortar is a factor influencing its toxicity. As for the waste in fired bricks, fired at a temperature of 900°</span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">C</span><span style="font-family:Verdana;"> or more, it offers convincing compressive and flexural strengths. The few research studies obtained on the use of mining waste in road embankments have shown that mining waste can be used as a sub-base layer and backfill as long as it is not toxic. In addition, several other mining wastes require special attention as substitutes for raw materials in construction materials, such as coltan, cobalt.</span></span></span></span>
