Research On Formula Optimization Of Ultra-light Ceramsite Prepared From Bauxite Tailings

With the rapid development of my country's alumina industry,a large amount of bauxite tailings and red mud have accumulated,occupied land resources,and polluted the environment.At present,there are few ways to absorb bauxite tailings on a large scale.Ceramsite is widely used in construction,petroleum,chemical industry and other fields due to its light,high-strength,heat and sound insulation,corrosion resistance,and high temperature resistance.Bauxite tailings are very suitable for the needs of ceramsite raw materials,so the use of bauxite tailings to prepare ceramsite is highly feasible,is a bulk way to absorb bauxite tailings,and can bring economic benefits for enterprises Benefits to achieve a win-win situation.With the goal of using bauxite tailings as ceramsite raw materials to prepare solid waste ultra-light ceramsite,first use analytical purification reagents as raw materials to fire the ceramsite,and explore the relationship between the chemical composition of the raw material and the ceramsite roasting.Guide the formulation optimization of solid waste ultra-light ceramsite.Through the method of single-factor condition test,the effects of calcination temperature,calcination time,the amount of alkali metal flux K₂CO_3,the amount of foaming material SiC,and the amount of Al₂O₃ on the apparent density of ceramsite products were investigated,and the chemical composition and roasting system were obtained.The law of influence on the performance index of ceramsite.With reference to the performance index,apparent phenomenon,chemical composition of raw materials and roasting rule of ceramsite of chemical reagent,bauxite tailings,red mud,kaolin tailings,copper tailings and granite sawing mud are used as solid waste materials to prepare solid Waste ceramsite,and the formulation optimization test of ceramsite raw material,finally successfully prepared solid waste ultra-light ceramsite,and by analyzing the performance index results of solid waste ceramsite,the universal applicability of the ceramsite roasting rule of chemical reagents was confirmed as Solid waste recycling workers provide reference.Using chemical reagents as raw materials to carry out an exploration test on the ceramsite roasting system,the following conclusions were drawn:when the roasting temperature is low and the roasting time is short,the ceramsite is insufficiently expanded and the density is high;when the roasting temperature is too high,the roasting time When it is too long,the ceramsite appears overburned,the shape collapses,the bubbles are unstable,and large-diameter through holes are likely to appear.Finally,the suitable roasting system was determined as follows:temperature rising rate from room temperature to 100°C was 10°C/min,holding temperature was 100°C for 10min,heating rate from 100°C to 700°C was 15°C/min,holding temperature was 700°C for 10min,700 The heating rate from?to roasting temperature 1140?is 10?/min,and the temperature is kept at 1140?for 30min.After determining the appropriate roasting system,adjust the influence of each component in the prepared raw materials on the density and lightness of the ceramsite.research shows:1.When the dosage of flux K₂CO₃ is between 9%and 13%,there is a significant fluxing effect.The more K₂CO₃ dosage,the lower the ceramsite density,and the higher the ceramsite density is,when it is higher than 13%;2.When the amount of SiC foaming material is between 0.15%and 0.45%,the ceramsite density is lower,and the appearance is better,and the pore uniformity is better;3.The content of Al₂O₃ is directly proportional to the density and unidirectional fracturing strength of the ceramsite.When the content of Al₂O₃ is higher than 19%,the ceramsite does not have expansibility.Refer to the above rules to guide the preparation of solid waste ultra-light ceramsite.Based on the roasting rule of chemical reagent ceramsite,the raw material formula of solid waste ultra-light ceramsite is adjusted to establish a roasting system.first using bauxite tailings,red mud,Kaolinite tailings were used to prepare ceramsite raw materials,and an orthogonal test was conducted to match the flux content adjustment with Al₂O₃ content.The final formula of the ceramsite raw materials was bauxite tailings:red mud:kaolinite tailings=3:3:4 Among them,the content of alkali metal flux is 15.15%and the content of Al₂O₃ is 18.32%.The adjusted solid waste ceramsite raw material obtains the best ceramsite performance index when the roasting temperature is 1130?:bulk density:387kg/m³,cylinder pressure strength:2.3Mpa,1h water absorption rate:3.25%.Then,bauxite tailings,copper tailings and granite sawing mud were used as raw materials to prepare ceramsite,and to verify the universal applicability of the first solid waste ceramsite formula and verify the sintering law of solid waste ceramsite.When the content of alkali metal flux is adjusted to about 15%,the content of Al₂O₃ is similar to that of the first solid waste ceramsite raw material.The chemical composition of the raw materials of the two ceramsites is only a large difference between the content of Fe₂O₃.The final performance of the ceramsite fired Compared with the first type of ceramsite,the analysis shows that too much Fe₂O₃ content in the ceramsite raw material will cause the liquid phase viscosity of the ceramsite to become lower,increase the density of the ceramsite,and cause the bubbles to merge seriously.The content of Fe₂O₃ in the ceramsite raw material should be less than 10%.Compared with the ceramsite prepared with analytical purification reagents and solid waste as raw materials,it has a high consistency in the firing rule,and can be used to guide the optimization of the formula of solid waste ceramsite,and finally use the optimized formula to burn out the accumulation The solid waste ultra-light ceramsite,which has a density of387kg/m³,a cylinder pressure strength of 2.3Mpa and a water absorption rate of 3.25%in 1hour,meets the national ultra-light ceramsite standard.The ultra-light ceramsite has excellent performance.