Thermodynamic Study on Production of High Purity Copper

为了估计Se在碳酸钠基炉渣和熔融铜之间的分配比，对含Se氧化物的炉渣在1423 K至1523 K的热力学性质进行了以下测量。(1)在<0.5><0.5>不同CO_2分压下，NaO_2-CO_2-SeO_2渣中NaO_2活度的电化学测定。（）0.667 {N = n_<Na>/（n_<Na>+n_<Se>），n为摩尔数}。(2)Se在炉渣和铜液之间的分配平衡测定;（3）CO_2在炉渣中的溶解度测定。估算了Se在渣-铜液间的平衡分配比随CO_2分压的变化关系。在1423 K和1523 K温度下，研究了渣中CO_2和O_2的含量与渣中成分的关系。在较高的氧分压和较低的CO_2分压下，2.还对N * 1渣系进行了氧分压对分配比的影响试验。Se的分配比对氧分压有两种不同的依赖关系。在相对较低的氧分压下，两种元素的分配比随氧分压的增加而减小，而在相对较高的氧分压下，Se的分配比随氧分压的增加而增加。在这两个地区，在较低的CO_2分压条件下，都能获得较高的分配比。

In order to estimate the distribution ratios of Se between sodium carbonate-based slag and molten copper, the following measurements have been conducted on the thermodynmic properties of the slags containing Se-oxide at 1423 K to1523 K.(1) Electrochemical measurements of activity of NaO_<0.5> in NaO_<0.5>-CO_2-SeO_2 slag under various partial pressues of CO_2 over the composition range of 1 > N (〕SY.gtoreq.〔) 0.667 {N = n_<Na>/(n_<Na>+n_<Se>), n : the number of moles} by using beta"-alumina as a solid electrolyte.(2) Distribution equilibrium measurements of Se between the slag and molten copper, and(3) Solubility measurements of CO_2 in the slags.Finally based on the results, the equilibrium distribution ratio of Se between the slags and molten copper have been estimated as a function of partial pressures of CO_2 and oxygen and the slag composition at the temperatures of 1423 K and 1523 K.Higher distribution ratios are achieved under conditions of higher partial pressure of oxygen and lower partial pressure of CO_2.Experiments were also conducted for the slag of N * 1 in order to evaluate the effect of partial pressure of oxygen on the distribution ratios. The distribution ratio of Se has two different dependences on the oxygen partial pressure. Under the relatively low oxygen partial pressure, the distribution ratio of both elements decreases with increasing oxygen partial pressure while under the relatively high oxygen partial pressure the distribution ratio of Se increases with increasing the oxygen partial pressure. In both areas, higher distribution ratios are achieved under the condition of lower partial pressure of CO_2.