Study On Preparation And Pore Structure Of Molybdenum Tailings Foamed Ceramics

Molybdenum tailings are solid wastes discharged from molybdenum ore in mining and beneficiation.and how to recycle them has become an urgent problem.A large amount of research and development work is dedicated to seeking comprehensive utilization solutions for molybdenum tailings,such as developing high-value products.The chemical composition of molybdenum tailings is mainly composed of Si O₂ and Al₂O₃,and its high content of silicon and aluminum makes it a potential raw material for the preparation of foamed ceramics,which not only reduces the production cost of foamed ceramics,but also realizes the high value-added utilization of molybdenum tailings.Based on this,the effects of sintering schedule and body composition on the properties of foam ceramics were systematically studied using molybdenum tailings as the main raw material;and characterize the high temperature liquid phase by measuring the height of the highest point of the triangular cone from the ground and the amorphous phasor obtained by X-ray diffraction pattern fitting,establish the relationship between the high temperature liquid phase and pore structure,and reveal the pore-forming mechanism of foamed ceramics.The main research results of this paper are as follows:（1）The firing system is the key to successfully preparing foamed ceramics.By adjusting the heating rate,firing temperature,and insulation time of the basic ratio,the effect of firing system on the properties of molybdenum tailings foamed ceramics was studied.The results show that increasing the heating rate is beneficial for improving the compressive strength of foamed ceramics,while the non-uniformity of pore size increases,leading to an increase in thermal conductivity.When the heating rate is 1℃/min,the comprehensive performance of foamed ceramics is good;The firing temperature and time have a significant impact on the pore structure of foamed ceramics.Increasing the temperature or prolonging the insulation time is beneficial for forming a uniform pore structure and obtaining foamed ceramics with good comprehensive performance.However,excessive temperature or time can lead to the merging and collapse of pores,thereby affecting the performance of foamed ceramics.（2）Based on the determined firing system and basic ratio in the previous section,the effects of Si C dosage,molybdenum tailings dosage,and RM/PF dosage ratio（red mud/potassium feldspar dosage ratio）on the properties of molybdenum tailings foamed ceramics were studied.The results show that Si C be forced to oxidize in silicate melts,and the amount of Si C determines the rate of oxidation reaction.As the amount of Si C increases,the pore structure of foam ceramics will experience an increase in non-uniformity.Therefore,0.8wt%is chosen as the optimal amount;The presence of feldspar phase in the molybdenum tail mineral phase can effectively reduce the viscosity of high-temperature melt,which is beneficial for reducing the apparent density and thermal conductivity.However,excessive addition will affect the uniformity of pore structure,so the reasonable dosage of molybdenum tailings is set at70wt%;As the RM/PF dosage ratio increases,the decrease in potassium feldspar dosage leads to a gradual increase in high temperature viscosity,a decrease in the average pore size of the sample,and a gradual increase in thermal conductivity.Therefore,the RM/PF dosage ratio is set to 1:1.（3）The relationship between the height of the highest point from the ground and the amorphous phasor and the pore structure was established to study the pore-forming mechanism of molybdenum tailings foamed ceramics.The results indicate that the height from the highest point of the temperature measuring triangular cone to the ground and the amorphous phasor can be used as an indicator to determine the uniformity of the pore structure.When the temperature measuring triangular cone shows a slight bending state,many small pores begin to form inside the sample;When the height of the highest point of the temperature measuring triangular cone changes within the range of 8mm～10mm from the ground,a uniform pore structure can be obtained inside the sample.When the temperature measuring triangular cone contacts the ground,it marks the beginning of instability and collapse of the pore structure.When the amorphous phasor is less than 50%,the growth of pore structure will be hindered.When the amorphous phasor is greater than 65%,the growth of pores will be excessively promoted,and pores may merge to form connected pores,resulting in the fracture of pore wall structure of the sample.When the amorphous phasor is in the range of 57%～62%,pores with uniform pore size will be obtained.There is a negative correlation between the height of the highest point off the ground of the temperature measuring trianglar cone and the fitting curve of amorphous phasor.