改性活性炭的粒级对吸附金-硫代硫酸根络离子的影响研究  

Effect of particle size of modified activated carbon on adsorption of gold-thiosulfate complex

作　　者：余洪[1] 宋文强 程彦玲 张汉泉[1] 谢蕾 YU Hong;SONG Wenqiang;CHENG Yanling;ZHANG Hanquan;XIE Lei(School of Resources&Safety Engineering,Wuhan Institute of Technology,Wuhan 430074,China)

机构地区：[1]武汉工程大学资源与安全工程学院,湖北武汉430074

出　　处：《中国矿业》2023年第1期141-149,共9页China Mining Magazine

基　　金：湖北省教育厅科学技术研究项目资助(编号:B2017055);武汉工程大学研究生教育创新基金资助(编号:CX2021462)。

摘　　要：硫代硫酸盐提金法是最有望取代氰化法的无毒提金方法,但浸出液中金-硫代硫酸根络离子Au(S_(2)O_(3))_(2)^(3-)无法经济有效地回收阻碍了该方法的工业应用。为了提高活性炭对Au(S_(2)O_(3))_(2)^(3-)的负载量,本文以三种粒级的活性炭为原料,采用三聚氰胺浸渍-高温热活化法制备了改性活性炭。通过静态吸附法、孔径与比表面积分析仪、SEM-EDS和XPS等方法详细研究了三聚氰胺用量、浸渍温度、热活化温度和时间等对改性活性炭吸附Au(S_(2)O_(3))_(2)^(3-)的影响和吸附机理。研究结果表明,粒级为0.45~0.90 mm的活性炭添加3.75%的三聚氰胺,50℃下浸渍改性后,在温度为750℃下热活化60 min,制备的活性炭对Au(S_(2)O_(3))_(2)^(3-)的负载量最大,为553.35μg/g。吸附机理研究发现,粒级为0.45~0.90 mm的活性炭改性后,具有较大的微孔占比和适宜的平均孔径;季氮官能团增加了活性炭表面的正电性,含氧官能团提升了活性炭的亲水性,这些因素共同作用极大提升了改性活性炭对Au(S_(2)O_(3))_(2)^(3-)的吸附能力。It is the most promising non-toxic method for thiosulfate gold leaching to replace cyanide extraction,but the failure of economic and effective recovery of gold-thiosulfate complex in leaching solution hinds the industrial application of this method.In this paper,in order to improve the loading capacity of activated carbon to Au(S_(2)O_(3))_(2)^(3-),modified activated carbon is prepared by high temperature thermal activation method with three kinds of different granular activated carbon as raw materials and melamine as nitrogen source.By static adsorption,particle size and specific surface area,SEM-EDS and XPS,the effects of melamine dosage,modified temperature,thermal activation temperature and time on the adsorption of gold on modified activated carbon and adsorption mechanism are studied in detail.The results show that the activated carbon with the particle size of 0.45-0.90 mm adding 3.75%melamine,modified temperature of 50℃,thermal activation temperature of 750℃for 60 min,the prepared activated carbon has the maximum adsorption capacity of 553.35μg/g for Au(S_(2)O_(3))_(2)^(3-).It is found that the average particle size and large proportion of micropores of 0.45-0.90 mm modified activated carbon is suitable for the adsorption of Au(S_(2)O_(3))_(2)^(3-) on activated carbon.What s more,the functional groups of quaternary nitrogen increase the positive electric property on the surface of activated carbon,and the functional groups of oxygen increase the hydrophilicity of activated carbon.These factors together greatly enhance the adsorption of Au(S_(2)O_(3))_(2)^(3-) on the modified activated carbon.

关 键 词：活性炭 改性 粒级 吸附 金-硫代硫酸根络离子 

分 类 号：TF831[冶金工程—有色金属冶金] TF114