Anodic Lodes and Scrapings as a Source of Electrolytic Manganese

Abstract

Abstract:Manganese is an element of interest in metallurgy, especially in ironmaking and steel making, but also in copper and aluminum industries. The depletion of manganese high grade sources and the environmental awareness have led to search for new manganese sources, such as wastes/by-products of other metallurgies. In this way, we propose the recovery of manganese from anodic lodes and scrapings of the zinc electrolysis process because of their high Mn content (>30%). The proposed process is based on a mixed leaching: a lixiviation-neutralization at low temperature (50 • C, reached due to the exothermic reactions involved in the process) and a lixiviation with sulfuric acid at high temperature (150-200 • C, in heated reactor). The obtained solution after the combined process is mainly composed by manganese sulphate. This solution is then neutralized with CaO (or manganese carbonate) as a first purification stage, removing H 2 SO 4 and those impurities that are easily removable by controlling pH. Then, the purification of nobler elements than manganese is performed by their precipitation as sulphides. The purified solution is sent to electrolysis where electrolytic manganese is obtained (99.9% Mn). The versatility of the proposed process allows for obtaining electrolytic manganese, oxide of manganese (IV), oxide of manganese (II), or manganese sulphate.

Recovery of Copper and Magnetite from Copper Slag Using Concentrated Solar Power (CSP)

“…In addition, recycling and reutilization of materials increases the efficiency of the industrial processes and, thus, the economic profitability of the industrial sector. In this context, new uses are being given to industrial wastes [65][66][67][68] and new potential processes are being considered, such as solar energy [69]. In this manuscript, we proposed the utilization of concentrated solar power (CSP) in the treatment of copper slag to recover/concentrate copper and iron from these slags.…”

Silicomanganese and Ferromanganese Slags Treated with Concentrated Solar Energy

“…If Mn would have been transformed into oxide (well-developed and with proper size), the sample could have been grinded and milled, and manganese oxides could have been recovered through gravimetric methods. These unfavorable results could make more interesting alternatively hydrometallurgical processes for manganese residues, as for instance, that used by Fernández-González et al, in the treatment of anodic lodes and scrapings from the zinc electrolytic process [10]. Maybe the addition of any reductant reagent or even increasing the quantity of calcium carbonate (or lime if calcined) would liberate manganese from the silicates present in the slag.…”

Impact of high volume E.M.D. residue on the corrosion resistance and mechanical properties of construction materials in sulfate environment

“…EMD waste materials are highly acidic, due to the presence of sulfuric acid (H 2 SO 4 ) used in the production of EMD [52]. Furthermore, these wastes may contain residual solvents or carbonaceous materials, contributing to their overall toxicity, while also containing heavy metals, such as Cr, Ni, and Cd, which can be harmful to human health and the environment [53,54]. Due to their hazardous nature, EMD wastes require proper handling and disposal to prevent environmental pollution and health hazards.…”