Performance Research And Application Of Fly-Clinker-Silicon-rich-Tailings Composite Cementitious Material

Abstract Annual production of cement reached2.5billion tons at present, and with rapid growth. Cement production requires large amounts of natural resources and energy, and emit large quantities of carbon dioxide, which greatly damaged the relationship between man and nature. The utilization ratio of industrial solid waste was low. In fact, some kinds of industrial waste can be used as substance fur cement clinker.In this paper, fly ash and silicon-rich tailings were used for the study. Mixed with right amount of cement clinker, composite cementitious material can be made.Alkaline activator should be used to improve activity of Composite cementitious material. The main works were as follows:(1)Composition of clinker, fly ash and silicon-rich tailings were analyzed. Based on this composite cementitious material was made. Investigate how alkaline activator, clinker content and fly ash content influence the strength of composite cementitious material.(2) NMR techniques was used to research the initial hydration performance. Results show us the trends of three kinds of water(adsorbed water, pore water and free water) in cementitious material slurry. The content of adsorbed water is over90%.(3)The ability of acid, alkali and salt resistance was determined by using immersion test. Results show that the ability of alkali resistance is better than acid and salt.(4) Heavy metals leaching tests were used to study the ability of the cured composite cementitious material of heavy metal ions, and it can be inferred the composite binder has a better ability to consolidate heavy metal ions.(5) Based on the above research, composite cementitious material was used to cement full tailings, and compared with pure cement, to evaluate the cement effect. Results show that, compressive strength of two kind of filling mass changed little, but the mobility of composite cementitious material is poor than that of pure cement. In the case of add in superplasticizer, composite cementitious material can be used to backfilling in the underground.