Study On Flue Accretion Problem Of Anode Copper Making Process Using Two Bottom Blown Furnaces

The copper smelting process from concentrate to anode using two bottom blown furnaces,with its commissioning in commercial uses,offers an alternative for the copper smelting industry of the world.It is characterized with short production flow,low Operating cost and capital expenditures,etc.Therefore its continuous improvement is of great significance for the development of the copper smelting technology.This study introduces briefly the copper smelting process from concentrate to anode using two bottom blown furnaces,and focuses on the flue accretion problem of the matte making furnaces,including its chemical and phase compositions,the formation mechanisms,influence factors,as well as,the controlling or eliminating methods.This study aims at providing the guidance for the operation of the matte making furnace.The main results and conclusions obtained in this study are as follows.（1）The dust yield of the smelting furnace increases with increment of the feeding mass.Larger feeding mass requires more gas injection volume,thus,resulting in more off-flue gas,as a result,the dust yield increases inevitably.The dust yield has a direct impact on the growth speed of the accretion（2）The impurities in the feeding,especially,lead and zinc,also affect the accretion formation in the flue to a certain degree.In the accretion,lead mainly exists in the form of low melting point eutectic melt between Pb O and Si O₂;while zinc mainly forms zinc franklinite,a refractory compound,which makes the accretion harder and denser,thus,difficult to eliminate.（3）The accretion formation process is a process of continuous change and development of the chemical composition and phase structures.This was testified by the fact found in the study that the accretion presents a multilayers structure;the chemical composition and phases are much different between layers.In the inner side of the accretion,the main phase is copper matte,a kind of eutectic melt of Fe S and Cu₂S.However,in the outside of the accretion,the iron oxide containing slag formed by splashing is the main phase.（4）To improve the accretion problem,many accretion inhibitors were tested.It was proved that those of high melting point were more recommendable.The inhibitors were added periodically and consolidated as interlayers in the accretion,making it easier to be eliminate through hammering.66 figures,35tables and 88 references.