Optimization of Geopolymer Ratio for Vanadium-Titanium Iron Tailings Base Geopolymer Based on Response Surface Methodology
In order to promote the high-quality and large-scale effective utilization of vanadium-titanium iron tailings,geopolymer cementitious materials were prepared using vanadium-titanium iron tailings as the main raw material.The Central Composite Design design in response surface methodology was used to study the effects of n(SiO2)/n(A12O3),Na2CO3 content and liquid-solid ratio on the compressive strength of geopolymer and reveal the mechanism of strength formation.A regression model was constructed to explore the degree of influence of various factors and their interactions,thus obtain the best perform-ance ratio.The results indicated that n(SiO2)/n(Al2O3)has the greatest impact on the compressive strength of geopolymer,while the liquid-solid ratio has the least impact,and there is a certain interaction between the three.Under the excitation of so-dium carbonate,vanadium titanium iron tailings and metakaolin undergo polymerization and hydration reactions,generating N—A—S—H gel and C—S—H gel and so on.At the same time,the micro aggregate effect of vanadium titanium iron tailings also contributes to the compressive strength of geopolymer,so the formation of geopolymer strength mainly comes from the dense structure closely interwoven between the gel and aggregate.With n(SiO2)/n(Al2O3)=2.7,Na2CO3 dosage of 55％,the liquid solid ratio of 0.25 mL/g,the predicted compressive strength of the geopolymer is 51.769 MPa,and the experimental value is 50.320 MPa.The relative error is within a reasonable range,confirming that the response surface method can effectively opti-mize the ratio and has good predictive ability.
vanadium-titanium iron tailingsgeopolymerresponse surface methodratiointeraction
万方数据
维普
