Study On Fluoride-free Mold Flux Of Thin Slab Continuous Casting

Mould fluxes is a very important and critical material during continuous casting of steel,the traditional fluoride flux addition to the problems existence of the Earth's environmental but alsao has adverse effects on the continuous casting itself and continuous casting equipents.Study on fluoride-free flux has a very important significance with the states take the environmental issues on and the emergence of green metallurgy.This paper emphasis on the fluorine-free slag,to meet the conditions of the thin slab continuous casting focusing on its melting temperature,melting rate and viscosity.Author test and determine the best chemical composition scopes of the fluoride-free powder for orthogonal experiment,suing chemical pure reagents and single-factor design method:The content of MgO range:7%～11%;the content of Li₂O range:0.5%～3.0%;the content of Na20 range:6%～10%;the content of B₂O₃ range:3%～7%;the content of BaO range:6%～10%.Using range analysis and variance analysis,through orthogonal,to study the chemical compositions of the slag how tu impact the flux performance.The results of Range analysis,1) The each component impact the fluoride-free flux melting temperature stength of the order is:B₂O₃＞Li₂O＞R＞MgO＞BaO＞Na₂O;2) The each component impact the fluoride-free flux melting rate stength of the order is:R＞Na₂O＞MgO＞Li₂O＞B₂O₃＞BaO;3) The each component impact the fluoride-free flux viscidity(1300℃) stength of the order is:Li₂O＞R＞B₂O₃＞BaO＞Na₂O＞MgO.The results of variance analysis,1) The each component impact the fluoride-free flux melting temperature stength of the order is:Li₂O＞B₂O₃＞MgO＞R＞BaO＞Na₂O;2) The impact of Li₂O,B₂O₃,BaO,Na₂O,MgO on the slag melting rate is very small,under the conditions of not carbonaceous materials in.3) The each component impact the fluoride-free flux viscidity(1300℃) stength of the order is:Li2O＞B2O3＞R＞BaO＞MgO＞Na2O.The results of range analysis and variance analysis are basic agreement.Selects a suitable melting temperature,melting rate and viscosity of slag as the base slag based on the range analysis and variance analysis,adding carbonaceous material to determine the appropriate allocation of carbon content.Carbonaceous material is added as a mixture form of graphite and charcoal,at the same time,the relationship between graphite and charcoal is chaatoal/graphite=1/3,and the melting temperature is 1076℃;the melting rate is 23.5s;the viscidity is 0.089 Pa.s (1300℃).In this paper,the results of industrial raw materials of pre-melten-type fluorine-free slag,using cement clinker,magnesia,Industrial barium carbonate,borax industry, spodumene,industrial soda,industrial lime,quartz sand,graphite abd carbon black powder.,are the melting temperature 1079℃;the melting rate 26.3s;the viscidity 0.094 Pa.s(1300℃).The melting temperature,viscidity and melting rate of the fluoride-free mold flux,the pre-melt-type slag of this article studede,are meet the requirements of 1 thin slab continuous casting,and adapted to Low Carbon Steel.The fluoride-free mold flux,stdudied in the laboratory,has a practical significance on the development of green metallurgy ande fluoride-free mold flux's industrial,and provide apractical guide ande reference for the thin slab continuous casting slag productional design.