The dissolution routes of chalcopyrite in acidic sulfate aqueous solution have been discussed by thermodynamic calculation under different aqueous species concentrations, such as Cu²⁺, Fe²⁺ and H₂S. The results show that for both oxidative dissolution and non-oxidative dissolution of chalcopyrite, the dissolution process undergoes several intermediate steps before completely decomposing to Cu²⁺, Fe²⁺ and elemental sulfur, in which bornite and covellite are the most likely intermediates. The dissolution routes of the secondary intermediates have also been discussed and covellite is the most likely final intermediate. Based on these results, some frequently reported phenomena, such as the existence of an optima redox potential range, the promotive action of the addition of Cu²⁺ and Fe²⁺ , as well as the preferential release of Fe²⁺ in the chalcopyrite leaching process, have been explained and elucidated.

The potential use of emulsion liquid membranes (ELMs) with LIX 7950 as the mobile carrier to remove heavy metals from waste cyanide solutions has been proposed. Relatively stable ELMs with reasonable leakage and swelling can be formed under suitable mixing time and speed during emulsification. The concentration of LIX 7950 and Span 80 in the membrane phase, KOH in the internal phase and the volume ratio of membrane to internal phases are also critical to ELM formation. The efficiency of copper and cyanide removal from dilute cyanide solution by ELMs is related to ELM stability to some extent. More than 90% copper and cyanide can be removed from dilute cyanide solutions by ELMs formed under suitable experimental conditions.

In this work, a mineralogical study and thermal decomposition analysis of jarosite residue sample from a zinc plant were carried out. The mineralogical analysis showed that the jarosite residue is mainly composed of four components, including jarosites, sulfates–hydroxides, sulfides and spinel. The distribution of relevant metallic elements in these components was characterized using a sequential extraction process. The X-ray diffraction results showed that AFe₃(OH)₆(SO₄)₂ and ZnFe₂O₄ are the main components of the jarosite residue sample. The thermal decomposition mechanisms of ammoniojarosite and sodium jarosite were studied by TG-DSC (Thermogravimetric analysis–differential scanning calorimetry). The thermal decomposition process and the corresponding mechanism of the jarosite residue were analyzed. The jarosite thermal decomposition process includes the removal of crystal water, dihydroxylation and deammoniation, desulfonation of component jarosite and desulfonation of component zinc sulfate.

The jarosite residue is a harmful byproduct of the zinc hydrometallurgical process and has been classified as hazardous waste due to its high content of heavy metals and poor stability. In this work, the recovery of valuable metals by synergistic disposal of jarosite residue with cement kiln has been investigated. A series of investigations were undertaken to assess the effect of amount of jarosite residue, roasting time, and the addition of CaCl₂ on phase transformation and migration of valuable elements in the cement clinker. When 25% of jarosite residue was added to the raw cement materials and roasted at 1400 °C for 30 min, the silicate content in the cement clinker reached 54.4%. In the presence of CaCl₂ as the mineralizer, the volatilization rates of Pb and Zn were 93% and 75%, respectively. The results indicated that jarosite residue can be used as the cement additive and valuable metals of Pb and Zn can be recovered simultaneously during the roasting process.

In the paper, glass ceramics used as architectural materials were prepared based on lead fuming furnace-slag (LFFS) by a synergistic sinter-crystallization method. The effects of Al₂O₃ addition on the crystallization phase, crystallization kinetics, and mechanical performance of glass ceramics were investigated. The results showed that the phases of the glass ceramics prepared were composed of gehlenite and wollastonite, and crystallization kinetics analysis showed that bulk crystallization dominated the overall crystallization process in the Al₂O₃ content range from 2% to 8%. The glass transition temperature and the crystallization peak temperature of the glass ceramics generally increased with the increase in the Al₂O₃ content. Additionally, the crystalline morphology gradually developed from sheet-like to spherical, while the number of pores increased and the bulk density gradually decreased. When the Al₂O₃ content was 2%, the bending strength of glass ceramics reached its maximum, 75.1 MPa, corresponding to a bulk density of 2.24 g·cm⁻³. Owing to the high strength and relatively low bulk density, the sintered glass ceramics appear promising for potential applications in lightweight construction tiles.

The viscosity and conductivity of the smelting slag of copper oxide concentrate are important for reducing the operating temperature. In this study, seven slag samples were prepared by the reductive smelting of copper oxide concentrate with different ferrous oxide contents. The viscosity and conductivity data of these CaO-MgO-FeO-Al₂O₃-SiO₂ samples were measured in the temperature range of 1290~1410 °C. Based on the structural features of aluminosilicate melts, the change and dependency relationships of their viscosity and conductivity were analyzed. The results show that there is a strong tendency to form orthosilicate even when the slag composition is acidic. The formation of fayalite would allow more Al³⁺ to form pyroxene with the six-coordinated structure. As a result, the polymerization degree and viscosity of the melt will be reduced. The ${\left[\mathrm{AlO}\right]}_4^{5-}$ as a network former will reduce the bonding strength of the structural units, thus reducing the slag viscosity at high temperature. In the experimental range, the logarithm of viscosity of each slag sample has a good linear relationship with its logarithm of conductivity. However, there is no uniform linear equation for these complex slags with wide composition variations. These results have potential guiding significance for the copper smelting process.