The Study On Preparation Of Yellow Phosphorus Furnace Slag Glass-ceramics And Harmless Treatment Of Chromic Slag

Industrial solid wastes such as yellow phosphorus furnace slag,chromium slag are produced more and more with the development of economy.How to recycle these industrial solid wastes is the problem of sustainable development.The preparation of glass-ceramic is a kind of high value-added way to make full use of industrial solid waste.A series of glass-ceramics was prepared using yellow phosphorus furnace slag as basic raw material in this paper.First,the effects of chemical component on the crystallization ability of glass-ceramics were analyzed based on crystallization kinetics;the types of the crystal phase of glass-ceramics were calculated by FactSage based on crystallization thermodynamics.Second,the effects of external factors on the crystallization ability of glass-ceramics were explored.Finally,a series of glass-ceramics were prepared using yellow phosphorus furnace slag and chromic slag as raw material.The crystallization ability of basic glass could be enhanced and then weakened with the increase of Cr₂O₃ content.The crystal ability of basic glass was the strongest by the addition of 0.9 wt%Cr₂O₃.The predominant crystal phase of glass-ceramic was wollastonite?CaSi O₃?and the minor crystal phases were cristobalite?Si O₂?and aluminian diopside Ca?Mg,Al??Si,Al?₂O₆).It did not change with the increase of Cr₂O₃ content.The crystallization ability of basic glass could be enhanced with the increase of ZnO content.The crystal ability of basic glass was the strongest by the addition of 7 wt%ZnO.The predominant crystal phase of glass-ceramic was wollastonite?CaSi O₃?and the minor crystal phase was aluminian diopside Ca?Mg,Al??Si,Al?₂O₆).It did not change with the increase of Cr₂O₃ content.The crystallization ability of basic glass could be enhanced and then weakened with the increase of CuO content.The crystal ability of basic glass was the strongest by the addition of 5 wt%CuO.The predominant crystalline phase of glass-ceramic was wollastonite?CaSi O₃?and the minor crystalline phases was aluminian diopside Ca?Mg,Al??Si,Al?₂O₆).It did not change with the increase of Cr₂O₃ content.Compareing with adding TiO₂,The crystallization ability of basic glass could be promoted when TiO₂+CaF₂ or TiO₂+P₂O₅ was added.Whereas in the case of adding TiO₂+Cr₂O₃ the effects is opposite.The major crystal phase of glass-ceramic was wollastonite?CaSiO₃?and the minor crystal phases were aluminian diopside?Ca?Mg,Al??Si,Al?₂O₆?and fluorapatite?Ca₅?PO₄?₃F?when any one of TiO₂,TiO₂+CaF₂,TiO₂+P₂O₅ and TiO₂+Cr₂O₃ was added.The calculated results by FactSage indicate that the crystal phases of glass-ceramics were wollastonite?CaSiO₃?,cristobalite?SiO₂?,diopside?CaMgSi₂O₆?,anorthite?CaAl₂Si₂O₈?and uvarovite(Ca₃Cr₂Si₃O₁₂)when Cr₂O₃ was added;the crystal phases of glass-ceramics wre wollastonite?CaSiO₃?,diopside?CaMgSi₂O₆?,cristobalite?SiO₂?and anorthite?CaAl₂Si₂O₈?when ZnO was added;the crystal phases ofglass-ceramicswerewollastonite?CaSiO₃?,diopside?CaMgSi₂O₆?,anorthite?CaAl₂Si₂O₈?,cristobalite?SiO₂?and sphene?CaSiTiO₅?when Cu O is added;the crystal phases of glass-ceramics were wollastonite?CaSiO₃?,diopside?CaMgSi₂O₆?,anorthite?CaAl₂Si₂O₈?fluorapatite(Ca₁₀?PO₄?₆F₂),sphene?CaSiTiO₅?and albite?NaAlSi₃O₈?,when any one of TiO₂,TiO₂+CaF₂ and TiO₂+P₂O₅ was added,but the crystal phases of glass-ceramics were wollastonite?CaSiO₃?,diopside?CaMgSi₂O₆?,anorthite?CaAl₂Si₂O₈?fluorapatite(Ca₁₀?PO₄?₆F₂),sphene?CaSiTiO₅?,albite?NaAlSi₃O₈?and uvarooite(Ca₃Cr₂Si₃O₁₂)when TiO₂+Cr₂O₃ was added.The thermodynamic calculation results were consistent with experimental results.The crystallization ability of basic glass could be influenced by atmosphere.The crystallization ability of basic glass was stronger in air atmosphere than in nitrogen atmosphere.The crystal phases of glass-ceramics was CaSiO₃ whether in atmosphere or in nitrogen atmosphere.The crystallization ability of basic glass could be influenced by melting time.The crystallization ability of basic glass could be weakened gradually with the increase of melting time.The predominant crystalline phase of glass-ceramics was wollastonite?CaSiO₃?and the minor crystalline phases was aluminian diopside Ca?Mg,Al??Si,Al?₂O₆).It did not change with the increase of melting time.The crystallization ability of basic glass could be influenced by cooling method.The crystallization ability of basic glass by water quenching was relatively stable.The cooling method could also influence the crystalline phase of glass-ceramics.Thepredominantcrystallinephaseofglass-ceramicswas wollastonite?CaSi O₃?and the minor crystalline phases was aluminian diopside Ca?Mg,Al??Si,Al?₂O₆)under natural cooling condition,but the crystalline phase of glass-ceramics was wollastonite?CaSiO₃?and the minor crystalline phase was aluminian diopside Ca?Mg,Al??Si,Al?₂O₆)under water quenching condition.A series of glass-ceramics could be prepared using yellow phosphorus furnace slag and chromic slag as raw material and adding different amount of silicon dioxide.The crystallization ability of basic glass could be enhanced and then weakened with the increase of chromic slag.The major crystal phase of glass-ceramics was wollastonite?CaSiO₃?and the minor crystal phases were aluminian diopside?Ca?Mg,Al??Si,Al?₂O₆?and ferric diopside?Ca?Mg,Fe,Al??Si,Al?₂O₆?when 10wt%chromic slag or 20 wt%chromic slag was added.The major crystal phase of glass-ceramics was wollastonite?CaSiO₃?and the minor crystal phases were aluminian diopside?Ca?Mg,Al??Si,Al?₂O₆?,ferric diopside?Ca?Mg,Fe,Al??Si,Al?₂O₆?and anorthite?Ca₂Al₂SiO₇?when 30 wt%chromic slag or 40 wt%chromic slag was added.The leaching toxicity of glass-ceramics met safety standards when 10 wt%⁴0 wt%chromic slag was added.