Studies on zinc recovery from technogenic waste

Marinela Panayotova,Vladko Panayotov,A.D Nazarov

doi:10.1051/e3sconf/202129503008

Marinela Panayotova, Vladko Panayotov + Show 1 more

Open Access

https://doi.org/10.1051/e3sconf/202129503008

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Abstract

Results from laboratory experiments are presented on extraction of zinc available in waste from lead-zinc metallurgy, mixed with lead-zinc flotation tailings and some waste rock, by leaching it under atmospheric conditions with sulfuric acid (H2SO4) solutions (5 and 10 wt. %) and 30 % hydrogen peroxide in the temperature range of 25 - 80 °C, at leaching time 30 - 120 min. Material leaching with 10 % H2SO4solution at 70 °C for one hour brings into pregnant leach solution (PLS) around 80 % of zinc available. Imposing an electrochemical impact during the leaching process increases the quantity of leached zinc by around 5 %. Direct electrowinning from the PLS obtains zinc metal of grade 75-76 %. The suggested treatment removes metals-pollutants from accumulated mixed technogenic waste therefore rendering it more environmentally friendly. Experiments showed that old mixed waste from mining, mineral processing and metallurgy activities merits further studies as secondary source of metals.

Highlights

Zinc is used mainly in preparing galvanic coatings for steel protection from corrosion, production of brass and bronze, zinc-based alloys and different chemical compounds
The need for metals has led to a demand for technologies for their extracting from other technogenic waste, such as slag from plants smelting lead and zinc, solid wastes from iron- and steelmaking plants, copper converter slag, flotation tailings, disposed mill tailings of sulfide ores, magnetite concentrates, pyrrhotine concentrates [18 - 21], low grade zinc concentrate obtained by flotation of gathered flotation tailings [22], land filled Znrich sludge and jarosite [23]
The results show that the electrochemical impact leads to an increase of about 5% in the leaching of zinc into the solution

Summary

Introduction

Zinc is used mainly in preparing galvanic coatings for steel protection from corrosion, production of brass and bronze, zinc-based alloys and different chemical compounds. The need for metals has led to a demand for technologies for their extracting from other technogenic waste, such as slag from plants smelting lead and zinc, solid wastes (sludge and slag) from iron- and steelmaking plants, copper converter slag, flotation tailings, disposed mill tailings of sulfide ores, magnetite concentrates, pyrrhotine concentrates [18 - 21], low grade zinc concentrate obtained by flotation of gathered flotation tailings [22], land filled Znrich sludge and jarosite [23]. Huge amounts of such types of waste are available worldwide. Based on the findings of the referred to studies and our experience, we have tested material leaching mainly with sulfuric acid solution

Materials and methods

Results and discussion

Conclusions