Study Of Synergistic Preparation Of Glass-cearmics From Yellow Phosphorus Slag And Dianchi Lake Sediment

Yellow phosphorus slag is a solid waste produced by the electric furnace for yellow phosphorus process,which main composition is SiO2,CaO,sediment is dredged silt produced by the process of eutrophication governance of lakes or rivers,the main components are Si02,Al2O3,Fe2O3,etc.At present,the main way of the phosphorus slag and sediment resources is building materials(such as cement,brick,etc.),which possesses low additional value and low solid waste utilization ratio,with the piling is the main treatment method,so that the hidden trouble in safety will be inevitable in soil,water,atmosphere environmental hazards risk and human health safety.Therefore,the technology with high additional value of the phosphorus slag and sediment efficient utilization production is necessitated problem.This research adopts the method of synergistic preparation of high additional value glass-ceramics to system research the influence law by the component(silica,fluxing agent,nucleation agent)and heat treatment on the crystallization and properties of glass ceramics,discusses the crystallization mechanism of the Slag of Yellow Phosphor slag-sediment glass-ceramics,providing new ideas for efficient utilization of the phosphorus slag and sediment.Experiments based on SiO2-MgO-CaO ternary phase diagram(Al2O3 content 10%)design the yellow phosphorus slag-sediment system glass-ceramic formula which solid waste amount is more than 90%,and establish the heat-treating process,and analyse the crystal phase composition(XRD),microscopic morphology(SEM),the physical and chemical characteristics,Fourier infrared(FTIR)and thermodynamics(DSC)of glass-ceramic,the product can be used as a fine building decoration materials.Research shows that:the SiO2 content increases the particle migration resistance,making it harder for nucleation and need more heat and higher nucleation temperature,at the same time hinders the crystallization of calcium magnesium long yellow crystal phase,promote the he crystallization of diopside and wollastonite,when coupled with SiO2 content more than 6%,there is a little change on the crystal phase type and the quantity,when synthesize its performance and economical efficiency,the optimal addition of SiO2 is 1.0%;With the introduction of Na2O,the wollastonite crystal phase,the original main crystal phase,is gradually disappear,when the addition of Na2O more than 3 wt%,wollastonite and diopside crystal phase disappeared completely with the main crystal phase transition into a single calcium aluminum long yellow crystal phase,which the main grain structure is thick sheet structure,this structure is easily appears the quenching cracks during annealing.This study discusses the influence of nucleation agent on the crystallization behavior of yellow phosphorus slag glass-ceramics and yellow phosphorus slag-sediment glass-ceramics respecively.The laws of CaF2 to the yellow phosphorus slag glass-ceramics is adding the nucleation agent CaF2 can significantly promote the crystallization of glass-ceramics and change the crystallization peak temperature and activation energy;With further adding CaF2 does not change the main crystalphase(wollastonite phase)type,it produces new CaF2 crystal phase,changes the grain size at the same time.When adding 2.5 wt%CaF2,the glass-ceramics activation energy is 281.54 kJ/mol,the crystallization index was 3.97.The results of research on the laws of the nucleation agent Cr2O3 to the yellow phosphorus slag-sediment glass-ceramics show that:the structure of glass-ceramics,crystallization and the physical and chemical performance can be optimized with adding Cr2O3.When adding 0.5wt%Cr2O3,it can significantly reduce the activation energy and the crystallization temperature,the dense microstructure makes the bending strength of the sample is up to 148.6MPa;Further to add Cr2O3,it turns a trend that the glass-ceramics crystallization behaviors is gradually transformed from one-dimensional crystallization into two-dimensional crystallization,thus make the ball grain number increase,needle-like grain number decreases,and the process is easy to produce micro structure defects,it makes the glass-ceramics bending strength decreased.