聚氨酯泡沫塑料吸附-火焰原子吸收光谱法测定铜选矿流程样品中金

Determination of gold in beneficiation process sample of copper by atomic absorption spectrometry after polyurethane foam plastic adsorption

在稍开马弗炉炉门的条件下焙烧样品后,采用盐酸、硝酸-氯酸钾溶样,用约0.2g经10%(体积分数,下同)盐酸浸泡24h后的聚氨酯泡沫塑料(简称泡塑)吸附样品中金,以自来水冲洗干净泡塑以去除吸附矿浆,然后直接用王水-高氯酸对泡塑进行消解,建立了泡塑吸附-火焰原子吸收光谱法(FAAS)测定铜选矿流程中金的分析方法。实验表明:高碳、高硫样品在稍开马弗炉炉门的条件下,650℃焙烧3.5h可以将碳处理干净;用0.2g经10%盐酸浸泡24h后的泡塑可将4.0mg金吸附完全;泡塑震荡吸附120min基本可以消除矿浆对吸附率的影响。在选定的实验条件下,金在0.20~1.0μg/mL质量浓度范围内与其对应的吸光度线性良好,相关系数为0.999 8,方法检出限为0.024μg/g。采用实验方法对铜选矿流程中铜原矿、铜精矿、铜尾矿中金进行测定,测定结果与标准方法 GB/T 3884.2—2012或GB/T 20899—2007均较为一致,相对标准偏差(RSD,n=11)不大于10%。

After the sample was roasted in muffle furnace with furnace door was slightly opened,it was dissolved with hydrochloric acid and nitric acid-potassium chlorate.Gold in the sample was adsorbed with 0.2g of polyurethane foam plastic which had been immersed in 10%（volume fraction,the below was the same）hydrochloric acid for 24 h.The polyurethane foam plastic was cleaned with water to remove the adsorbed ore pulp,and then directly digested with aqua regia-perchloric acid.Thus,a determination analysis method of gold in beneficiation process sample of copper was established by flame atomic absorption spectrometry（FAAS）after polyurethane foam plastic adsorption.The experimental results showed that carbon in high-carbon high-sulfur sample could be fully removed after roasting at 650 ℃for 3.5hwith the furnace door slightly opened 4.0mg of gold could be adsorbed completely with 0.2g of polyurethane foam plastic which had been immersed in 10% hydrochloric acid for 24 h.The influence of ore pulp on adsorption rate could be basically eliminated by oscillation adsorption for 120 min.Under the selected experimental conditions,the mass concentration of gold in range of 0.020-1.0μg/mL showed good linearity to its corresponding absorbance with correlation coefficient of 0.999 8.The detection limit of method was 0.024μg/g.The proposed method was applied for the determination of gold in beneficiation process sample of copper（raw copper ore,copper concentrate and copper tailings）.The results were consistent with those obtained by national standard methods（GB/T 3884.2-2012 or GB/T 20899-2007）.The relative standard deviations（RSD,n=11）were not more than 10%.