Red Mud Preparation Cbc Road Base Material

Red mud is the solid waste discharging in the process of alumina smelter industrial production. At present, red mud stack stock has beed accumulated over 100 million tons in china, but its utilization rate is only about 15 percent, so far as a large number of red mud in an effective way has not yet been founded. Solving the red mud caused by the waste of resources and environmental pollution has become a very urgent task in alumina industry.This experiment was based on red mud in the bayer process and red mud sintering as the main raw materials, with industrial waste such as fly ash, slag, gypsum,porcelain agent, and addition agent according to a certain proportion mixed,used the static compaction law, and prepared at room temperature conservation CBC roadbed materials. Unconfined compressive strength as the main indicators, the red mud as the main raw material conditions was explored, meeting the performance requirements of the roadbed material with the best ratio.The basic properties of red mud and CBC curing agent were studied, the physical and mechanical properties of materials were tested, and using XRD and SEM microstructure of the material were characterized and curing CBC red mud samples curing mechanism was studied, the technical and economic and application prospects of CBC roadbed material production by red mud were analysised,for the size of red mud utilization to provide theoretical and technical basis. The results show that:(1) based on red mud in bayer process, selected porcelain agent, fly ash, gypsum, slag and other material for the main components of the curing agent, through the orthogonal and single factor test to find out the additive the best composition, under experimental conditions at the best with the ratio of porcelain agent:fly ash:gypsum:slag:red mud= 7:5:5:5:78 was obtained. The 7d unconfined compressive strength of roadbed material with adopting the program to prepare had greater than 5MPa, it was fully able to meet a variety of level of the technical requirements of the roadbed, and after the conservation of 7 days,it did not appear phenomenon of efflorescence on the curing object. With the conservation of time, the strength of the curing material promoted sustainly, and the 28d unconfined compressive strength of it could reach more than 10MPa.(2) based on red mud red mud sintering, also selected porcelain agent, fly ash, gypsum, slag and other material for the main components of the curing agent, through the orthogonal and single factor test to find out the additive the best composition, under experimental conditions at the best with the ratio of porcelain agent:fly ash:gypsum:slag:red mud= 7:5:2:5:81 was obtained. The 7d unconfined compressive strength of roadbed material with adopting the program to prepare had greater than 6MPa, it was fully able to meet a variety of level of the technical requirements of the roadbed, and after the conservation of 7 days,it did not appear phenomenon of efflorescence on the curing object. With the conservation of time, the strength of the curing material promoted sustainly, and the 28d unconfined compressive strength of it could reach about lOMPa, and processed the performance of a good water stability.(3) Optimizing the curing agent composition and content, when the curing agent was 4%, the content will be able to fully meet the requirements of the road base material, but for sound reasons, the proposed content of 6 percent.(4) The means such as a combination of physical and mechanical properties, freeze-thaw performance andwet and dry cycle,etc.,were adopted to study the performance of the red mud curing object. It shows that CBC solidification red mud has good adaptability, stability, good physical and mechanical properties and durability.(5) The X-ray diffraction analysis showed that:the mineral composition of 7d and 28d of the curing object from CBC solidification red mud obvious changed,and generated a more stable and complex aluminum silicate structure, with high strength characteristic.(6) SEM indicated that, hydrated mineral of the CBC curing red mud is the sheet product, because of the stacked structure of criss-crossing the plate, between the three levels closely bite, so it demonstrates outstanding properties,and is also reasons. That CBC curing red mud significantly different from lime andcement curing agent.(7) The analysis of economy and technology showed that:using industrial wastes as the main raw materials to produce CBC curing agent has the advantage of a low-cost and abundant source of raw materials, simple production technology,and input-output ratio; with this curing agent curing red mud to produce roadbed material has strong market competitiveness and better economic efficiency. It can effectively solve the problem of environmental pollution and waste of resources about red mud, and will be able to promote the technical progress of the implementation of circular economy in alumina industry.