Study On Performance Of Thermally Activated Coal Gangue-slag-fly Ash Geopolymer

With coal gangue, slag and fly ash as main raw materials, use its rich clayey minerals, under the action of alkaline silicic acid, to preparate geopolymer which properties is similar to the "Geopolymer",called coal gangue-slag-fly ash geopolymer.Due to geological polymer can use industrial solid wastes as main raw material, and not only has excellent structure characteristics and durability, but also has good economy and environmental protection, therefore, much attention has been paid to become a research hotspot.This paper is a subproject of the national natural science foundation of China coal joint project 《research of gangue in cement and concrete resource utilization of key scientific problems》 (U1261122).All the research results are funded by this foundation.This paper studies the thermal activation of gangue, select the calcination temperature, holding time and cooling way three factors, according to the orthogonal table L16(45) of mortar strength of orthogonal experiment was carried out, revealing the effects of heat treatment process on coal gangue activity, in order to determine the coal gangue reactivity best process system;Next, the experiment is designed according to the method of uniform design in the horizontal, with dosage of coal gangue, slag, modulus of sodium silicate, sodium potassium ratio and dosage of ligand concentration of solution for the variable, with coal gangue, slag and fly ash geopolymer mortar intensity as the objective function, using MATLAB software to deal with the test data,to establish quantitative mathematical relationship between them,and give the the optimal mixture ratio; Final preparate geopolymer with the optimal mixture ratio,and detect its fineness, setting time and strength of mortar and volume stability the main technical properties of cementitious materials.Specific research contents and results are as follows:(1)Fuxin QingHeMen mine gangue best thermal activation process:Calcination temperature of 650℃, holding time 2h, air-cooled cooling.Various factors influence the degree of order of size:Thermal activation temperature> cooling system> holding time>Interaction of thermal activation temperature and holding time.(2)By uniform experiment, it is concluded that a series of regression equation of the coal gangue-slag-fly ash geopolymer 3d and 28d the flexural, compressive strength.With establishment of the formula, it can estimate the coal gangue, slag and fly ash geopolymer of 3 d and 28 d of the flexural, compressive strength value,when the coal dosage,slag content,sodium silicate modulus,potassium and sodium ratio and silicate concentration is known.and it has a practical guiding significance to engineering.(3)The fineness of coal gangue, slag, fly ash geopolymer is 1003.07m2/Kg、the initial setting time, final set time are 60min and 90min、volume stability qualified, four indicators all meet the technical requirements of the national standard of Portland cement, and show the characteristics of rapid hardening, early strength of the technology.