Preparation And Properties Of Ceramic Materials From Spodumene Flotation Tailings In Western Sichuan

As a special bulk industrial solid waste,flotation tailings are usually directly stacked in tailings pond after flotation.This treatment method will occupy a lot of land resources and even endanger the environment and human health.Therefore,the resource utilization of tailings has important practical significance.In this paper,spodumene flotation tailings were used as the main raw material to explore its comprehensive utilization.The potential of spodumene flotation tailings as raw material for ceramic materials,porous ceramic materials and low-temperature sintering adsorption materials was studied.Firstly,the basic physical and chemical properties of spodumene flotation tailings were analyzed through a series of characterization tests.In the research on the preparation of domestic ceramics from tailings,the effects of binder mass ratio,sintering temperature and mass ratio of raw materials on the properties of ceramic materials were explored to select a suitable preparation conditions.Porous ceramics with high porosity were prepared by hydrogen peroxide foaming method,but there was a problem of obvious shrinkage at high temperature.Considering that low melting point glass powder can produce liquid phase at lower sintering temperature,low melting point glass powder was selected as raw material in order to reduce the sintering temperature through a liquid phase sintering.Finally,low-temperature sintered porous adsorbents were prepared by combining foaming method with low-temperature sintering.The main conclusions of this paper are as follows:Firstly,ceramic materials were prepared with kaolin as binder.The main reasons for the densification of ceramic materials were that the appearance of the glass phase filled some voids between the particles,and the enhancement of mass transfer at high temperature made the neck of the particles bond together and shorted the center distance of particles.The melting of feldspar and its eutectic phase in the three major mineral components(quartz,feldspar and muscovite)in Spodumene tailings was the main reason for the densification of ceramic materials.When the ridge material quartz was used as the main raw material,the flexural strength was increased with decreased particle size of quartz.However,the dehydroxylation reaction of layered muscovite at high temperature resulted in the increase of the layer spacing and the destruction of the crystal structure.Secondly,porous ceramic materials with porosity of 64.14% were prepared by hydrogen peroxide foaming method.The sintering temperature and the mass ratio of kaolin were the two most important factors affecting the physical properties of porous ceramics.When the sintering temperature was 1150 ? and the mass ratio of kaolin was 10%,the porous ceramic materials with flexural strength,compressive strength,apparent porosity and water absorption of 2.46 MPa,4.96 MPa,52.48% and 44.96% respectively could be prepared.In addition,low melting point glass powder(LPG)was used as high-temperature binder to prepare low-temperature sintered materials with good mechanical properties at 550 ?.The results show that when the proportion of low melting point glass powder was 30 wt.%,the sintering temperature was 650 ?,the bending strength and compressive strength of the sample were the largest,which was 19.55 MPa and 42.25 MPa respectively.At this time,the average apparent porosity of the sample was as high as 24.52%,which was due to the accumulation of pores between particles.The appearance of the liquid phase caused by the melting of low melting point glass powder was the main reason for the adhesion between particles.Finally,based on the above research,low-temperature sintering and chemical foaming were combined to prepare porous adsorption functional materials.The apparent porosity of the prepared material was higher than 50%,the flexural strength was higher than 5.5 MPa,and the linear shrinkage was only 1.43%,which overcame the problem of severe shrinkage of porous ceramics at high temperature.In addition,due to the decreased sintering temperature,kaolin did not completely dehydroxylate into metakaolin,which maintained the adsorption performance of kaolin.It realized the loading of adsorption performance of porous materials,eventually.