Flotation Test Study On Copper Recovery From Converter Blowing Sla

In the world,97%of the copper has been produced by pyrometallurgy,which always results in the production of the copper smelting slag.The copper grade in this kind of slag is usually higher than that in the minable copper ores in China,and moreover,it is usually accompanied with valuable gold,silver,lead,zinc,cobalt,nickel and other metals,becoming very important resources with a high recycling value.In the background of copper resources increasingly depleting,the comprehensive recycling of the copper smelting slag has gradually become a trend.According to the different copper smelting technology,the copper slags produced can be approximately classified into three types:the copper smelting slag,the copper converting slag and the copper refining slag.Among those,the copper converting slag inevitably contains as high as about 4%～8%copper element because of the strong oxidizing stirring of the copper matte and iron during the converter smelting process.Therefore,it will be a huge waste of copper resources,if such a high value slag is discarded directly.Nowadays,the recycling methods of the copper converting slag are mainly smelting and flotation at home and abroad,and the latter is the most widely used one.In order to fully recover the valuable metals in the copper converting slag,copper slag flotation plants have already been built or are being built in many main copper metallurgy enterprises in China at present.Without taking up the capacity of smelting furnaces,and with a higher recovery,a lower costs than impoverishment smelting,the flotation technology of copper converting slag has become the most economic and effective method for copper recovery from the slag.The slag sample used in this research(a slow cooling slag from the copper converter blowing)is taken from a state-owned copper metallurgy enterprise in Yunnan province,with a X-ray fluorescence spectrum analysis,the process mineralogy property of the slag has been detailedly investigated.It has been found that the metals with comprehensive recycling values in this slag are copper,gold and silver.The contents of 2.09%Cu,0.2g/tAu and 25g/tAg,have been determined,respectively.Based on the process mineralogy properties of the slag,tests on flotation reagent system and flotation flowsheet for this converter slow cooling slag have been conducted.The flotation reagent system obtained from the tests is as follows:mixed butyl xanthate and butyl ammonium aerofloat as the collector,sodium sulfide as the activator,sodium silicate as the adjuster,and 2#oil as the frother.And the suitable flotation flowsheet consists of two roughers,two cleaners and two scavenger.The final experiment results obtained with the recommended flotation flowsheet and the reagent system are as follows:the copper grade of concentrate is 18.61%,the recovery of copper 84.58%,the gold grade 0.60g/t,and the grade of silver51.70g/t.To the“once roughing,once concentrating”maginetic separation flowsheet,Fe grade 60.02,and recovery 61.77%concentration are gained.So these results have further demonstrated the feasibility and effectiveness of the flotation technology for the treatment of the copper converter slow cooling slag,thus providing a reliable basis for the application of the flotation technology in this enterprise.