| Copper slag contains plentiful copper,iron and other valuable metals.Traditional copper slag is made up of silicates,the copper's grade less than 5% and the iron's up to about 40%.With the increasing of copper's production and consumption,the recycle of scrap copper can not only offset the shortage of copper,but also effectively reduce the production of wastes and protect the environment and resources,especially for a relatively poor copper resources country.Therefore,the recycle of scrap copper must become an integral part of the copper's metalluragy and there is a certain amount of scrap copper smelting slag producedin the production process.In the paper,the raw material is scrap copper from the Jiangxi Tungsten Alloy New Material Co.,Ltd's the Bright Copper Pole's production slag.The production process of the Bright Copper Pole is Spain Paul Lafargue FRHC scrap copper refining process.also calling High conductivity copper fire refining production process.The annual output of copper of this copper slag is about 800 tons and its market value is more than $ 4,000,000.Based on the nature and characteristics of the copper slag,under argon atmosphere conditions,the copper slag's copper can be recycled by Pyrometallurgical depleted method and that can achieve the reuse of the copper.The FRHC copper slag was analyzed by chemical analysis,XRD,SEM and the copper and iron phase analysis.The results showed that the copper of the slag accounts for 15.80%,mainly metal copper,free copper oxide,combined with the presence of cuprous oxide state,and the iron of the slag accounts for 8.83%,mainly in iron phosphate,metal iron and the magnetic iron oxide form,and the phosphorus of the slag accounts for 15.16%,the silicon of the slag accounting for 0.17%.The copper slag is different from traditional slag because it is a kind of copper slag phosphates.Deteced by high temperature phase analyzer,the copper slag softening temperature is 1090?and the copper slag hemisphere temperature is 1184?,and the copper slag flow temperature is 1212?.The FRHC copper slag was depleted by single factor Pyrometallurgical depleted method.According to the results,we got the optimum conditions.The optimum conditions is holding temperature 1275?,after addition of 3.75% graphite powderranging from 200 mesh to 400 mesh and 2% calcium oxide,holding time 80 minutes.comparing adding proper calcium oxide with no adding,the copper's yield grow slowdown twenty minutes earlier and its yield increase by six percentage points.Under optimized process conditions obtained above,different additives were added to bath based the optimum conditions.We have added respectively calcium fluoride,sodium carbonate and high sodium barium.By comparing the three additives,the calcium fluoride is the most.The copper's yield is 85.08% and the coper's grade is96.33% when the amount of calcium fluoride addition is 1.5%.And the levels of iron and lead is 0.237% and 0.891%.The size of graphite is from 200 mesh to 400 mesh and five factor and four level crossing link experiments were designed.According to the experiments,the results convinced that the most optimum is keeping temperature at 1300?,adding 4%graphite powder,adding amount of lime and fluorite are around 2% and 1%,holding80 minutes.Under the most optimal process condition,we got the result that the yield of copper is up to 85.81%.And the depleted copper block contained 96.45% copper,the order of several elements of higher metal impurity is 0.96% lead,0.35%nickel,0.36% tin,0.3% phosphorus,0.216% zinc,0.204% iron. |
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