Behavior of Tin and Antimony in Secondary Copper Smelting Process

Abstract

Different types of metal-bearing wastes, such as WEEE (Waste Electrical and Electronic Equipment), are important urban minerals in modern society, and the efficient recycling and reuse of their metal values is of key interest. Pyrometallurgical copper smelting is one of the most prominent ways of treating WEEE, however, more accurate experimental data is needed regarding the behavior of different elements during each process stage. This article investigates the behavior of tin and antimony, both commonly present as trace elements in electrical and electronic waste, in secondary (i.e., sulfur-free) copper smelting conditions. The experiments were conducted in oxygen partial pressure range of 10−10–10−5 atm, covering the different process steps in copper smelting. The basis of the equilibrium system was metallic copper–iron silicate slag, with the addition of alumina and potassium oxide to account for the presence of these compounds in the actual industrial process. The results showed that the distribution coefficients of both trace metals, LCu/slag = [wt % Me]copper/(wt % Me)slag, increased significantly as a function of decreasing oxygen pressure, and the addition of basic potassium oxide also had an increasing effect on the distribution coefficient. A brief comparison between EPMA and LA-ICP-MS (electron probe microanalysis and laser ablation–inductively coupled plasma–mass spectrometry), the two in situ analytical techniques used, was also presented and discussed.

Recycling of tellurium via copper smelting processes

“…The most important experimental parameters have been collected in Table 1. A more detailed description of the experimental set-up has been presented earlier [23].…”

“…The total sample mass was approximately 0.4 grams and equilibrations were performed in small cylindershaped alumina crucibles (> 99.5% Al 2 O 3 , Degussit AL23, Friatec NA, Germany; ID 8 mm and H 15 mm). The distribution behavior of nickel, tin and antimony in the system have been presented in our previous publications [23,25]. After equilibration, the quenched samples were cast in epoxy resin, followed by grinding, polishing and carbon coating.…”

“…The alumina concentration in the slags, 17-19 wt%, remained virtually unaffected by the changes in oxygen potential. More details of the composition of the slag, spinel and copper phases have been published earlier [23,25].…”

“…Based on the slope (black line in Fig. 6) [23,25], tellurium dissolved into the slag as TeO in oxidizing conditions of secondary copper smelting, i.e. above 10 −2 Pa oxygen partial pressure.…”

Thermodynamic-Based Exergy Analysis of Precious Metal Recovery out of Waste Printed Circuit Board through Black Copper Smelting Process

“…So, copper from any sort of metallurgical, industrial, or consumer waste is considered secondary copper. Smelting in a shaft furnace is the most common pyrometallurgical route for refining copper from secondary sources [28][29][30][31]. However, the process has its own issues, such as impurities associated with the secondary materials.…”