Study On Preparation Of Foam Concrete With Vanadium Tailings

Vanadium tailings are solid wastes produced by industrial acid leaching of vanadium.Because of the lower V₂O₅ taste in vanadium ore resources and big differences tailings properties caused by the different ore and different beneficiation process,it is difficult to recycle vanadium tailings.Resulting in a large number of vanadium tailings deposit,bring a negative impact to the economy and environment.Therefor,study on characteristics of vanadium tailings in Shanyang,Shanxi Province in this paper.Then study on the activation mode of vanadium tailings and the technical feasibility of preparing foamed concrete by vanadium tailings.It provides the basic theory support for comprehensive utilization of vanadium tailings.The basic properties of vanadium tailings were studied.The results show that there are higher SiO₂ in the chemical composition of vanadium tailings,mainly in the form of quartz,and a small amount of minerals such as gypsum,feldspar and pyrite are also present in the tailings.At the same time,activation of vanadium tailings was carried out by different activation methods and the activity of vanadium tailings was evaluated by the activation index K28.The results show that when the mechanical grinding combined with chemical excitation for vanadium tailings,the activity index increased to 85.1%.The vanadium tailings activated in this way can be used as the ideal siliceous material for the production of building products.Through single factor test and orthogonal test and considering the utilization of vanadium tailings and foam concrete product performance.,oming to optimize the preparation of vanadium tailings foam concrete mixing ratio?mass percentage?: vanadium tailings 40%,slag 34%,lime 5%,13% of cement clinker,gypsum 8%,water to material ratio of 0.6.Compressive strength of products is the 3.70 MPa,dry density is 592kg/m3.Meet the A06,C3.5 foam concrete requirements,which the JG / T266-2011 "foam concrete" industry standard required.Analyze the sources of vanadium tailings strength of foam concrete articles by XRD,SEM process of hydration reaction mechanism.It is concluded that Si-Otetrahedra and Al-O-tetrahedrons in the surface of the slag and tailings are broken and recombined to form C-S-H gel and ettringite under the common action of alkali excitation and sulfate excitation.The overall density of the gel material is improved because of the needle-like calcium-vanadite crystals interspersing in the pores of the gel.So the strength of products increased.In addition,good pore structure can improve the compressive strength in a certain range.Use professional software “Image-Pro Plus” to analysis distribution of pore structure of foamed concrete.Study on influences of the distribution of pore structure on product performance.And provide some basic theories for the study of the correlation between pore structure and product properties.The results show that when the composition of raw materials is same,and the porosity of the products is roughly equal,the distribution of stomatal structure will have a greater impact on the strength properties of products.When the most of the pore size distribution in the average pore size,the compressive strength of products will achieve the best.