Tham khảo tài liệu 'extractive metallurgy of copper 4th ed. w. davenport et. al. (2002) episode 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Batch Converting of Cu Matte 137 Table . Distribution of impurity elements during Peirce-Smith converting of low and high grade mattes Vogt et al. 1979 Mendoza and Luraschi 1993 . Ag Au and the Pt metals report mainly to blister copper. Tenmaya et al. 1993 report that extra blowing of air at the end of the coppermaking stage lowers As Pb and Sb in the converter s product copper. 54 Cu matte feed 70 Cu matte feed distribution distribution to 10 to to to to blister converter converter blister converter converter Element copper slag offgas copper slag offgas As 28 13 58 50 32 18 Bi 13 17 67 55 23 22 Pb 4 48 46 5 49 46 Sb 29 7 64 59 26 15 Se 72 6 21 70 5 25 Zn 11 86 3 8 79 13 For this reason some smelters treat the dusts for impurity removal before they are recycled Shibasaki and Hayashi 1991 . Bismuth in particular is removed because i it causes brittleness in the final copper anodes and ii it can be a valuable byproduct. Industrial Peirce-Smith Converting Operations Tables Industrial Peirce-Smith converters are typically 4 m diameter by 11 m long Table . They consist of a 5 cm steel shell lined with m of magnesite-chrome refractory brick. Converters of these dimensions treat 300-700 tonnes of matte per day to produce 200-600 tonnes of copper per day. A smelter has two to five converters depending on its overall smelting capacity. Oxygen-enriched air or air is blown into a converter at 600 Nm3 minute and atmospheres gage. It is blown through a single line of 5 cm diameter tuyeres 40 to 60 per converter. It enters the matte to 1 in below its surface nearly horizontal Lehner et al. 1993 . The flowrate per tuyere is about 12 Nm3 minute at a velocity of 80 to 120 meters per second. Blowing rates above about 17 Nm3 minute tuyere cause slopping of matte and slag from the converter Johnson et al. 1979 . High blowing rates without slopping are favored by deep tuyere submergence in the matte Richards 1986 . About half of the world s Peirce-Smith
