The Study Of Environmental-friendly Taphole Clay

Taphole clay is a kind of functional refractory materials which used to block the tap hole to ensure the well production of furnace tap hole.Meanwhile,it shall be easily opened in order to ensure the molten iron coming out form the blast furnace,and keep the taphole in a proper depth.With the development and process of the society,people have realized the huge danger of traditionally tap-hole clay bonded by coal tar and asphalt.One of the most typical PAHs is Benzo[a]pyrene?BaP?,which has a strong carcinogenic activity.To be environmental-friendly and body healthy,it's urgent to develop taphole clay with low BaP to meet the need of modern iron and steel industry.Therefore,in this work,a kind of environmental-friendly resin systhesized in experiment and a new kind of pitch were used to control the BaP content in whole sample.The effects of the resin,pitch,ferroence addition,calcium alumino-titanate and heat-treatment temperatures on properties of tap-hole clay have been investigated.The results are shown as follow:?1?The combination and operational performance were optimized when the phenol molar ratio,oxalic acid and reaction time were 1:0.85,1 wt%and 1.5 h,respectively.With the increase of resin,Marshall value,hot modulus of rupture?HMOR?,bulk density?BD?,cold crushing strength?CCS?,slag resistance decreased gradually,while apparent porosity increased.By raising the temperature,the BD and CCS first decreased and then increased,while AP first increased and then decreased.?2?With the increase of pitch,Marshall value and BD decreased,while HMOR,CCS and slag resistance increased gradually.The oxidation resistance first rose and then declined,while AP variation was opposite.By raising the temperature,the CCS increased,the BD first decreased and then increased,while the AP variation was opposite.All the samples demonstrated shrinkage after firing at 1100?due to the binder carbonization.However,the mullite formation at 1400?followed by some expansion could negate some shrinkage,leading to some sample demonstrated expansion.?3?Using some ferrocene as anti-smoke could effectively reduce the smoke of taphole clay and have no negative effect on the physical and chemical properties.With the increase of ferrocene addition,the anti-smoke effect and AP first increased and then decreased,while the CCS and BD first declined and then rose,oxidation resistance declined gradually.The CCS and BD decreased,while AP increased by raising the temperature.?4?The solid waste calcium alumino-titanate main phases were CA6,Ca((Al_0.84Ti_0.16)₂)₆O₁₉9 and CA₂.Oxidation resistance were reduced,but the slag resistance improved after the brown alumina were replaced by calcium alumino-titanate.