Preparation And Study Of The Bauxite Tailings Using For High-Strength Silicon-Aluminum Ceramics

Bauxite tailings is a bauxite mine waste that cannot be used as aluminum or refractorymaterials,but also a valuable resource if handled properly. It can not only reduces productioncosts and bring greater economic benefits, but also be conducive to the protection ofenvironment and has great influence on ceramic industry if the low-grade bauxite tailings canbe reused directly into the ceramic tile productions.Firstly, this thesis refers the MgO-Al2O3-SiO2phase diagram and choose a high Al2O3content areas for exploratory experiments. It uses pure oxide as raw materials, and the A/S isnear1:1.This thesis also studies the impact on experiments brought by different (CaO+K2O+Na2O) of the total amount of additives: if the amount of solvent is too high, the strength anddense of the silicon and aluminum porcelain will be worse. The results show that when thechemical composition range of MgO is generally2~5%、Al2O345~55%、SiO240~53%,the performance of the sample fired at1200℃si the best; when the total amount of additivesof (CaO+K2O+Na2O) is3%, MgO is2.9%, Al2O343.6%, SiO250.4%, the bulk density ofceramics can be2.33g/cm3, water absorption is3.22%, flexural strength is89.2MPa.Whenthe inevitable Guizhou bauxite tailings iron and titanium components is added, and selectedingredient in the above formula composition range,the bulk density of ceramics fired at1200℃can be2.61g/cm3, water absorption1.8%, flexural strength133.1MPa.Secondly, physical and chemical properties of two low-grade bauxite tailings areanalyzed, and on the basis of pure oxide formulations, we uses bauxite tailings as main rawmaterials and made high strength ceramics at a low temperature: when using the bauxitetailings1as main raw materials and firing at1226℃,the firing shrinkage of the samples canbe10.7%, bulk density is2.59g/cm3, water absorption is0.06%and flexural strength of129.5MPa. Moreover, the impact on the results caused by the composition fluctuations is alsostudied: when using the bauxite tailings2as main raw materials and firing at1200℃,thefiring shrinkage of the samples can be9.0%, bulk density is2.46g/cm3, water absorption is5.58%and flexural strength of124.2MPa.The results show that composition fluctuationsmade small affect on flexural strength, but big affect on water absorption of the ceramics.Finally, paper studies the effects of trace elements using orthogonal test method phosphorus, lithium, titanium and rare earth elements on the performance of these ceramicsprepared the basic formula, results show that rare earth element1had great impact on thesintering and mechanical properties of ceramics, and performance of the ceramics improvedgreatly with increasing content of the REE1: adding0.24g REE1, water absorption isreduced from22.56%to13.76%, lower by as much as39%, while the flexural strengthincreased from34.2MPa to58.7MPa, increased by as much as71.6%;Rare earth elements2and pentoxide have great affect on the sintering properties,but small affect on mechanicalproperties;Rare earth elements3, titanium dioxide and lithium oxide have small affect on theperformance of ceramic.