Research On The Distribution Characteristics And Direction Control Of Arsenic In Copper ISA Smelting Proces

In recent years,with the consumption of high-grade copper ore,the impurity content in the concentrate has gradually increased.The harmful element arsenic is difficult to remove in the smelting process and accumulates in the copper smelting system,which ultimately affects the quality of cathode copper.Therefore,the oxygen-enriched top-blown smelting experiment of mixed copper concentrate was carried out in this paper.The mechanism of arsenic fixation in slag at 1160℃（1433K）was studied.According to the distribution characteristics of arsenic in each phase,arsenic was enriched in slag in the form of stable arsenate.The results show that the ability of slag to absorb arsenic can be effectively improved by changing the composition of slag and increasing the basicity of slag.At the same time,the arsenic fixation of Pb,Zn and Bi in copper smelting dust was studied,which provided a theoretical basis for the control of arsenic in copper smelting process.Combined with the actual production of copper top-blown smelting in an enterprise,the distribution ratio of harmful arsenic in flue gas and dust is 55～75%,the distribution ratio in matte phase is 10～20%,and the distribution ratio in slag phase is 20～35%.In this paper,the distribution and trend regulation of arsenic in copper top-blown smelting process were theoretically analyzed,and the effects of process parameters such as Fe/Si O₂,oxygen-enriched concentration,matte grade and Ca O content on arsenic distribution rate in different outputs were investigated under laboratory conditions.The results show that by controlling the oxygen concentration of 55vol%and 65vol%respectively,the optimal distribution rate of As in the slag is determined by the change of Ca O content and Fe/Si O₂in the slag,and As is regulated into the slag.At the same time,after optimizing the process parameters,the proportion of As in slag is 30～40%,the proportion of flue gas and dust is50～60%,and the proportion of matte is 5～15%,so as to control the content of arsenic in each product.The main stage of arsenic fixation in dust is the oxidation of trivalent arsenic to improve the fixation rate of arsenic and the stability of final arsenic residue.In copper pyrometallurgical smelting,in addition to the use of fixing agents（such as Ca O and Fe O）to fix arsenic,Pb,Zn and Bi in the form of oxides in the flue system of copper smelting can also be used as arsenic fixing agents to react with As₂O₃ to form stable arsenate.In view of the high content of Pb,Zn and Bi in some copper concentrates,the impurity components in production were simulated by adding Pb O,Zn O and Bi₂O₃.The results showed that the arsenic fixation rates were as high as 91.03%,90.21%and 90.11%,respectively,with the addition of different arsenic fixation agents.The As₂O₃ in the dust could be converted into stable arsenate and fixed in the dust.