Study On Gelation Characteristics Of Micro-Powder In Iron Tailings And Its Concrete Preparation

As a kind of solid waste,iron ore tailings has low utilization rate and bring mang environmental and safety problems.On the other hand,because of its fine grain,easy to grinding and potential hydraulic after grinding,use iron power as the application of mineral admixtures in concret,that not only turn wast into available resources but also reduce the energy consumption and resource consumption in cement industry and environmental pollution.In this paper,first of all,the mechanical properties of iron ore taikings power cement wad studied.Secondly,through XRD,FSEM,2020 m ASAPanalyzed the net iron ore tailings power cement slurry hydration product,micostructure and pore distribution.Finally,apply iron ore tailings to concret and studied the working properties,mechanical properties and durability of the concrete,and the following main conclusions:(1)Tailings iron power has a certain hydraulic but does’t have ash properties,the mechanical properties of the test piece will decrease with the increase of its content;Although the incorporation of iron tailings powder will adversely affect the early strength of the test piece,the strength growth after 28 days is equivalent to that of the control group and iron tailings fine powder can alleviate the strength of cement latex retraction.(2)Under the autoclave condition,the iron tailings fine powder has good gelation performance,which can be secondary hydrated with calcium hydroxide produced by hydration of cement,and the hydration gelation degree is improved,so that the mechanical properties of the mortar can be improved,At the same time,autoclaved curing will also have a certain impact on the microstructure of the test block,will increase the porosity of the test block to increase the proportion of harmful holes and pests.(3)Iron ore tailings powder cement-based hydration products mainly for:calcium hydroxide,hydrated calcium silicate,dicalcium silicate,tricalcium silicate.Changing the curing age or curing condition had no effect on the type of hydration product.(4)The effect of iron tailings powder on the performance of concrete is not obvious.When the content of iron tailings is varied in the horizontal range,the concrete slump is about 90mm,and the working performance is moderate.Concrete content of iron tailings has obvious influence on the mechanical properties of concrete.However,when the dosage is not more than 15%,the compressive strength and flexural strength of concrete are 32.5.(5)The tailings of iron tailings have a great influence on the durability of concrete.The ability of anti-chloride ion permeation and anti-carbonation of concrete is decreased with the increase of iron powder tailings,but when the content of iron tailings is less than 15%,The resistance to chloride ion permeability,anti-carbonization durability of life to meet the requirements of practical engineering.