Research On Carbonation Consolidation Process Of Ferrous Dust

Carbonate of iron pellets can realize dust containing iron and other solid wasteresource utilization and CO2greenhouse gas emission reduction and possess greatenvironmental, economic and social benefits, through the experiment study the processparameters which exert a influence on quality of green pellets and the process ofparameters which exert a influence on the carbonation pellets quality influence, and studythe carbonation reaction process kinetics. The main research contents and conclusions areas follows:Green pellets for preparing test using CaO as binder, after digestion of CaO particlesform Ca(OH)2colloid attachment in iron containing dust particles, pellets has a certainstrength of CaO ratio and green pellets water the content increase will make pelletscompression strength increased first and then decreased, falling strength has beenincreased, but the increase is relatively small; extended pellets making time, green pelletsmechanical strength will be increased;To extend pellets making time, the mechanicalstrength of pellets will not have too greatly improved;the higher the CaO ratio,the higherthe pellets moisture content, pellets the longer making time of pellets will reduce thenumber of small diameter ball, large size pellets will increase obviously, particle size istoo large or small, will be made pellets in the mechanical strength to adverse. The CaOratio is M3%, the ball in water content is W2%, pellets making time of t3min pelletizingproperty and pellet quality best.Carbonation process results in high density CaCO3, thereby improving thecarbonation quality of pellet. The reaction temperature of T4℃, gas flow rate of L2L/min,gas volume ratio is V4%, the maximum degree of pellet carbonation. The greater thecarbonation is, i.e.The higher of CaO conversion rate is, the smaller porosity, carbonationpellet strength increase. Reaction time20min, along with the extension of reaction time,There is no obvious improvement of the carbonation reaction degree.Carbonation test shows that, the carbonation process can be divided into two stages:the first stage carbonation reaction rate is fast; second stage along with the reaction, CaOconversion rate increased slightly, but the reaction rate is very slow. Carbonation reactionconsists of interface chemical reaction and gas diffusion in the early stages, carbonationreaction, chemical reaction is restricted link; in the late, diffusion is restricted link. T1~T2and T2~T4temperature carbonation reaction activation energy were6.641kJ· mol-1and16.005kJ·mol-1.So, the green ball preparation parameters and carbonation reaction processparameters on the carbonation pellet quality greatly, the topic for the dust containing ironcarbonate pellet practical applications to provide theoretical support and technicalguidance.