Basic Experimental Research On Preparation Of Oxidized Pellets With Sea Sand Mine

Sea sand mine is a iron ore resource formed by river,wave,tide and current scouring.Titanium magnetite is the main phase.It is rich in reserves,easy to pick and choose,and low in price.It can be used as a raw material for blast furnace iron making.However,because its sea sand mine contains vanadium,titanium and other elements,the shape of the particles is regular,mostly spherical or elliptical,the surface is smooth,the grain size is coarse,and it has not been used on a large scale in the steel industry.In order to achieve the purpose of large-scale use of sea sand mines in iron and steel enterprises as ironmaking raw materials,this paper has carried out related research on the preparation of oxidized pellets in sea sand mines based on the principle of optimized ore blending.Firstly,the basic characteristics of the raw materials for the preparation of sea sand mine pellets were tested and analyzed.The chemical composition,phase composition and particle properties of the pelletizing materials were mainly studied.Then,low proportion sea sand mine pellets by prepared,The effects of low proportion sea sand mine on the cold properties and reduction properties of pellets were studied,and the influence mechanism was analyzed briefly.Finally,based on the previous research,the proportion of sea sand mine is continuously improved,and the influence of high proportion sea sand mine on the cold properties and reduction properties of pellets is studied.Through the research of this paper,the main conclusions are as follows:(1)The New Zealand Sea Sand Mine used in the test is a vanadia-titania magnetite composed of phases such as hematite,magnetite and ilmenite spinel.The sea sand mine is black sand-like crystal,the shape of the particles is relatively regular,mostly spherical or ellipsoidal,the granular texture is smooth and shiny,the grain size is coarse,and the ball forming properties is poor.(2)According to the principle of optimized ore blending,the sea sand mine,Sijiaying and Yuantong 14 mines were used as raw materials to prepare oxidized roasting pellets,and the performance and analysis of pellets were carried out.It is found that with the increase of the amount of sea sand mine,the falling strength of the raw pellets and the crushing strength of the finished pellets of sea sand mine gradually increase,while the crushing strength of the raw pellets gradually decreased,but still meet the requirements of the production of blast furnace ironmaking raw materials.(3)Through the reduction properties of low proportion sea sand mine pellets were tested and analyzed,it is found that the amount of sea sand mine is gradually increased,the reduction swelling index of pellets is gradually increased,and the crushing strength of pellets after the reduction swelling shows a gradual decline;the reduction index of the pellets is inhibited,the degree of reduction is decreased,and the crushing strength of the pellets after reduction gradually reduced,but it can still be used as a raw material for blast furnace ironmaking.(4)On the basis of the research on the low proportion sea sand mine pellets,the research on the addition amount of sea sand mine is carried out.It is found that with the increasing amount of sea sand mine,the prepared pellets tend to be flat.Forming pellet performance deteriorates,the falling strength of the raw pellets and the crushing strength drop sharply;the crushing strength of the finished pellets firstly increased and then decreased,but both meet the requirements of the national second-class pellets crushing strength.(5)Through the reduction properties of high proportion sea sand mine pellets were tested and analyzed,it is found that with the increasing amount of sea sand mine,the reduction swelling index of finished pellets firstly increased and then decreased,the crushing strength of pellets after the reduction swelling generally showed a downward trend;the degree of reduction of sea sand mine pellets gradually decreased,and the crushing strength of the pellets after reduction also decreased.