Study On The High Temperature Melting Performance And Crystallization Characteristics Of Red Mud And Fly Ash Imitation Basalt

Red mud and fly ash are large industrial waste residues generated in the process of industrial development,and their comprehensive utilization is related to the sustainable development of society.As a raw material for basalt fiber production,basalt has a large fluctuation in its chemical composition and a high iron content,which has troubled the development of the basalt fiber industry.In terms of chemical composition,red mud and fly ash are similar to basalt,so the use of red mud and fly ash to prepare basalt-like refractory materials has certain research significance.Therefore,in order to develop high-performance imitation basalt materials,this article uses red mud and fly ash as the main raw materials to prepare imitationThe experiment prepared red mud-like basalt material or fly ash-like basalt material by adding Al₂O₃,Si O₂,Fe₃O₄,Mg O,Ca CO₃,Na CO₃,KOH and Ti O₂ into red mud or fly ash;Adding industrial grade raw materials such as alumina,quartz,potash feldspar,albite,dolomite and talc to prepare red mud-fly ash imitation basalt material.In order to obtain the imitation basalt material with crystallization ability and high temperature viscosity close to that of basalt,the phase composition and chemical composition of the raw materials were analyzed.With the help of thermodynamic software,the chemical composition of the imitation basalt material is designed,and then the raw material composition is calculated according to the chemical composition of the raw material and the target imitation basalt material composition to prepare the imitation basalt material.The investigation of high-temperature viscosity found that the viscosity values of red mud and fly ash with different phases and compositions at the same temperature differ greatly.But after the experimental ingredients were prepared into imitation basalt materials with similar compositions,their viscosity values at the same temperature were very close.This shows that the high-temperature viscosity of the imitation basalt material is largely determined by its chemical composition.Moreover,the high-temperature viscosity of basalt material obtained by thermodynamic design is very close to that of basalt.In addition,the introduction of KOH and Na₂CO₃ makes the high-temperature viscosity of basalt samples increase to varying degrees,but the effect of KOH on the viscosity is more obvious.Through different heat treatments,it is found that the increase in cooling rate is conducive to the formation of glass phase.At the same cooling rate,the crystallization ability of some of the simulated basalt materials prepared in the experiment is lower than that of the basalt sample.When the experimental sample was kept at a lower heating temperature（1400°C）,a large number of crystals existed in the sample after cooling to room temperature due to insufficient melting of the experimental sample.Insulation of the sample during the cooling process can easily lead to the generation of crystals inside the sample,and with the extension of the holding time,the precipitation of crystals will become more and more serious.In addition,the introduction of sodium oxide and potassium oxide will destroy the stability of the basalt matrix,resulting in the formation of crystals during cooling.And this phenomenon becomes more and more obvious with the increase of the introduction amount.The experimental process investigated the imitation basalt materials prepared from red mud and fly ash samples with different phase compositions,and found that when their chemical compositions are close,the high temperature melting performance and crystallization ability of the test samples are also very close.This shows that the properties of the minerals relative to the sample do not constitute an influence,but that their close chemical composition determines that they have similar high-temperature melting properties and crystallization capabilities.