降低电炉炉结厚度及渣含铜的方法探究

Study on the method of reducing electric furnace accretion and copper content in slag

电炉炼铜生产过程中,适当的炉结厚度可以对炉体形成保护层,但过厚的炉结会大幅降低炉内的有效容积率、增加炉渣中铜含量,炉结厚和渣中含铜高是电炉炼铜生产的两大技术难题,也是解决电炉产能增长的最终途径。本文对炉结的成分及性质进行了分析,认为渣中Fe_(3)O_(4)的含量是决定炉结厚度的关键,渣中Fe_(3)O_(4)的含量高不但增加铜在渣中的机械夹带,而且会加剧铜在渣中的化学溶解损失。通过对Fe_(3)O_(4)还原分解的热力学和动力学条件进行分析,本文给出了有效降低渣中Fe_(3)O_(4)含量的措施:采用通过小油枪将柴油、白砂和N2同时喷入炉底的方案;在油气体积比为1∶17~1∶20条件下,还原渣中Fe_(3)O_(4)时,油枪的最佳插入深度为0.2~0.3 m,降低渣含铜时,油枪插入渣层厚度的1/2~3/5,处理炉结时,油枪插至炉底再上提50~100 mm;合理控制入炉原料配比,按比例加入熔渣量1.6‰的Na_(2)CO_(3)。实施该方案后,电炉炉结厚度降至平均452 mm,电炉渣含铜降至月平均0.498%,产生了较好的经济效益。

In the process of electric furnace copper smelting,a proper thickness of the furnace accretion can form a protective layer on the furnace body,while a much larger one would lead to a great reduction of the effective volume ratio of the furnace and increase of copper content in the slag.The determination of thickness of the furnace accretion and high copper content in the slag are two major technical issues in electric furnace copper smelting production,and also the final way to increase the capacity of electric furnaces.By analyzing the composition and properties of the furnace accretion in this paper,it is concluded that the content of Fe_(3)O_(4) in slag is the key to the thickness of furnace accretion.The high content of Fe_(3)O_(4) not only increases the mechanical entraining of copper in slag,but also increases the loss of chemical dissolution of copper in slag.By analyzing the thermodynamic and kinetic conditions of the reduction and decomposition of Fe_(3)O_(4),effective measures to reduce the content of Fe_(3)O_(4) in the slag are given in this paper:diesel oil,white sand and N2 are sprayed into the bottom of the furnace by a small oil gun;When the volume ratio of oil to gas ranges from 1∶17 to 1∶20,the optimal insertion depth of oil gun is 0.2~0.3 m when the Fe_(3)O_(4) in reducing slag is reduced,the oil gun is inserted into 1/2~3/5 of the slag layer thickness when the copper content in slag is reduced,and the oil gun is inserted into the bottom of furnace and then lifted 50~100 mm when the furnace accretion is treated.Besides a proper control on the ratio of raw materials,Na_(2)CO_(3) flux with slag content of 1.6‰should be added in proportion.When this scheme was carried out,it is found that the thickness of the furnace accretion is reduced to an average of 452 mm,and the copper content of the slag is reduced to a monthly average of 0.498%,indicating a good economic benefit.