Study On Preparation And Properties Of Polymer Artificial Stone From Tungsten Tailings

The utilization rate of tungsten tailings in China is low,tungsten tailings have become a solid waste that needs to be studied and treated urgently in China.Using tungsten tailings to prepare inorganic geopolymer artificial stones can alleviate the pressure on the environment caused by tailings,while reducing the production cost of artificial stones.In this paper,a tungsten tailings of gravity concentration were selected as the research object,tungsten tailings are used as aggregate and filler,fly ash and metakaolin are used as cementitious materials,and artificial stones are prepared in two ways of single mixing and mixed mixing cementitious materials.Using the compressive and flexural strength of artificial stones as the criteria for determining their mechanical properties,phase analysis was conducted on the finished products of artificial stones using characterization methods such as XRD,FT-IR,and SEM.The preparation process and mechanism of geopolymer artificial stones were studied,and the optimal preparation process of artificial stones was explored;Finally,optimize the grading of tungsten tailings aggregate and explore its impact on the mechanical properties of artificial stones.The main summary are as follows:（1）The physical properties of tungsten tailings-metakaolin based artificial stones are affected by multiple factors.The raw material conditions during the test can affect the performance of artificial stones,and the curing conditions after molding can also affect the performance of artificial stones.Na OH has the greatest impact on the finished product of artificial stone.The concentration of Na OH and the ratio of Na OH water glass in the alkali activator affect the mechanical properties of artificial stone by changing the alkaline condition of the alkali activator.（2）The effect of solidification temperature on artificial stone of tungsten tailings is significant.For fly ash artificial stones,increasing the curing temperature of the finished artificial stone results in a sudden increase in the mechanical strength of the artificial stone,from 40℃to 60℃,and a compressive strength increase of 189.86%.Heating up can enhance the activity of fly ash and promote the polymerization reaction of fly ash.The Al-O and Si-O bonds in the active Al₂O₃ and Si O₂ of fly ash continuously break,and then polymerize in the form of Al-O-Si bonds,ultimately forming a high-strength amorphous cementitious structure.（3）Optimizing the particle size ratio of aggregate can effectively improve the mechanical properties of tungsten tailings artificial stone.The influence of fractal dimension on the artificial stone made from different cementitious materials is different,when the fractal dimension F=2.6,the metakaolin based artificial stone has the best mechanical properties,and the compressive strength is 53.71 MPa;the best mechanical properties of fly ash based artificial stone are obtained when the fractal dimension F=2.4,and the compressive strength reaches 78.57 MPa.The spherical structure of fly ash can be used to fill the aggregate grading with poor compactness.The aluminum silicate generated by the polymerization reaction of fly ash can further wrap the tailings,resulting in high compactness and density inside the artificial stone,achieving better physical properties.