【摘要】 以HCl作为酸浸介质,考察热活化及碳酸钠助剂+热活化耦合活化两种活化方式下,煤矸石物料在酸浸过程中Al,Fe,Ca,Mg,K和Ti等金属离子的溶出活性,采用X射线衍射光谱(XRD)和红外光谱(IR)对活化前后的物料及酸浸渣进行矿物组成和微观结构表征,并根据金属在煤矸石中的矿物存在形态对金属离子的溶出活性进行解释.结果表明,在750℃热活化作用下,煤矸石中Al,Fe,Ca和Mg大量溶出,K的溶出率很低,Ti基本上不溶出;加碳酸钠助剂活化不仅有利于Al的溶出,同时滤液中金属离子K,Ti和Na也大量溶出,增加了滤液分离提纯和铝产品制备的难度.此外还研究了煤矸石热活化-酸浸工艺过程中金属离子的溶出规律,提出了酸浸预除杂的措施.更多还原

【Abstract】 The dissolution of metal ions such as Fe,Al,Ca,Mg,K and Ti from coalgangue were investigated under two different activation ways,thermal activation and thermal activation with Na2CO3 as additive.Hydrochloric acid was used as leach media.ICP-OES was used to determine the metal ion concentration in the aqueous phase.XRD and IR were used to analyze the mineral components in the coal gangue samples before and after activation,as well as the leaching residues.The dissolution properties of the metal ions were explained according to the mineral existence form of the metals in the coal gangue.The results show that Al,Fe,Ca and Mg can be quantitatively dissolved from the coal gangue after thermal activation.Only 31% of K can be dissolved in the experimental condition,while Ti can be barely dissolved.Thermal activation with Na2CO3 as additive can promote Al dissolution,the impurity metals ions like K,Ti and Na were largely dissolved into the leach liquor at the same time,which brings difficulty to prepare high-purity of aluminum products.The dissolution characteristics were specially investigated for the thermal activated coal gangue.By pre-leaching the activated coal gangue sample in6mol/L hydrochloric acid for less than 5min can remove most of the impurity metal ions,by preleaching the activated coal gangue sample in≤1mol/L hydrochloric acid first can remove Ca and Mg,then in ≥8mol/L hydrochloric acid can removal Fe.更多还原