The Effect Of Iron Oxides On Crystallization Behavior Of Tailings Glass Ceramics

At present,it is difficult to get the comprehensive utilization of tailings in China.The utilization rate is only 7%,and a large number of useful elements are wasted,which can't be used effectively.As the content of silicon and iron are slightly high in tailings of Anshan,it will make economic benefit to manufacture glass ceramics using iron tailings,which not only solve the problems caused by tailings accumulation,but also make full use of iron oxides in tailings,and creating economic value.The existence of Fe O and Fe2O3 must be considered in the preparation of glass ceramics using iron tailings,because Fe²⁺ and Fe³⁺ play different roles in the glass structure network when they are independent or co-existing.Therefore,the glass ceramics formulations with different Fe O and Fe2O3 contents were prepared using the chemical purity by simulating the mineral composition of iron tailing in Anshan,The tailings glass ceramics were prepared through sintering method.DSC,XRD,SEM and other detection means were used in the experiment.This paper investigated the dynamic process of crystallization of glass ceramics,phase analysis and microstructure were also studied;The density,porosity,water absorption of the samples were measured by immersion method and specific gravity method,with the aim of acquiring advanced and reasonable process,and providing technical support and theoretical basis for more effective utilization of iron tailings in Anshan area.Through the experiment,the test and the result analysis,the main conclusions of this paper are as follows:?1?When Fe²⁺,Fe³⁺ are independent,Fe²⁺ is more effective than Fe³⁺ in decreasing the crystallization activation energy of glass ceramics;when Fe²⁺ and Fe³⁺ exist at the same time,keeping the content of Fe³⁺ unchanged,the activation energy is increased with increasing the content of Fe²⁺,thus determining Fe²⁺ and Fe³⁺ proportion has become extremely important.?2?Crystallization kinetics analysis is using on the tailings glass ceramics.The results show that there is a reasonable numerical range of crystallization kinetics parameters,crystal growth index is gradually increasing with the decrease of heating rate.Especially at 5? /min,which the glass ceramics crystal growth index reaches the maximum value,n=6.13.?3?As far as this experiment is concerned,using chemical pure reagent to simulate the preparation process of Anshan tailings glass ceramics,when the ratio of iron ions(Fe³⁺/ Fe²⁺)is 2:4,the spinel which is the main phase tailings of glass ceramics can be produced.