铜熔炼渣中组元Fe_(3)O_(4)对铜的阻滞行为及机制

Blocking behaviors and mechanism of component Fe_(3)O_(4) on copper in copper smelting slag

机械夹带和化学溶解是造成铜冶炼过程金属损失的主要路径,而这两种损失路径均受铜熔炼渣成分影响明显。以Fe_(3)O_(4)和Cu2O为研究对象,模拟铜熔炼造渣过程的主要条件,研究铜熔炼渣中组元Fe_(3)O_(4)对铜的阻滞行为。研究结果表明:组元Fe_(3)O_(4)对铜离子具有明显的阻滞效应,包括化学溶解阻滞和物理性阻滞。化学阻滞主要是Cu(Ⅰ)与Fe_(3)O_(4)结构中次晶格八面体中Fe(Ⅱ)发生离子交换,取代部分铁位形成Fe(Ⅲ)—O—Cu(Ⅰ)键,铜离子被滞留在四氧化三铁晶格中形成铜掺杂态铁氧化物;物理阻滞主要与以Fe(Ⅲ)为网络形成剂构建的玻璃网络体有关,Fe(Ⅲ)与渣中[SiO4]四面体中的Si—O键结合形成Fe(Ⅲ)—O(BO)—Si键,桥氧键含量增加导致渣黏度增大,铜离子和金属铜颗粒流动性变差,被Fe(Ⅲ)—O(BO)—Si网络体包裹进入玻璃体中,造成铜熔炼渣中铜的多元化损失。通过提高铜熔炼渣碱度,破坏玻璃网络结构和Fe_(3)O_(4)结构中Fe(Ⅲ)—O—Cu(Ⅰ)键,可以明显增加铜的资源化回收效果。

Mechanical entrainment and chemical dissolution are the main paths for copper loss, which are significantly affected by the composition of copper smelting slag. Taking Fe_(3)O_(4)and Cu2O as the research objects,the main conditions of the copper smelting slag-making process were simulated, and the blocking behaviors of the component Fe_(3)O_(4)on copper in the copper smelting slag was studied. The results show that the component Fe_(3)O_(4)has obvious blocking effect on copper ion, including chemical dissolution blocking and physical blocking.Chemical retardation is mainly related to the ion exchange between Cu(Ⅰ) and Fe(Ⅱ) in the sub-lattice octahedron in the Fe_(3)O_(4)structure, substituting part of the iron sites to form Fe(Ⅲ)—O—Cu(Ⅰ) bonds, resulting in copper ion being retained in the metal-doped ferric oxide;physical retardation is mainly related to the glass network constructed with Fe(Ⅲ) as the network former, and Fe(Ⅲ) combines with the Si—O bonds in the [SiO4] tetrahedron in the slag to form Fe(Ⅲ)—O(BO)—Si bond, which will increase the proportion of bridging oxygen bonds in the slag, and increase the viscosity of the slag. The fluidity of copper ion and metallic copper particles becomes poor, and they are encapsulated into the glass body by the Fe(Ⅲ)—O(BO)—Si network, resulting in the diversified loss of copper in the copper smelting slag. The recycling effect of copper can be significantly increased by increasing the basicity of copper slag and destroying the Fe(Ⅲ)—O—Cu(Ⅰ) bond in the glass network structure and Fe_(3)O_(4)structure.