Title: Processing of industrial wastes with the aim to obtain zinc, tin and lead - based marketable products

Principal investigator: prof. Ing. Tomáš Havlik, DrSc.

Duration: 2015 - 2019

Acronym: RECWAZ

Anotation: The lack of raw materials results in processing wastes, often with higher content of metal than in primary raw materials. This is also in the case of zinc. The EU Commission declared the Raw Material Initiative based on three pillars: 1. Ensuring a level playing-field in access to resources in third countries; 2. Fostering a sustainable supply of raw materials from European sources; 3. Boosting resource efficiency and recycling. Qualified estimates suggest that primary Zn sources are available only for 20 years. Therefore, the objective of this project is focused on recycling of Zn containing wastes with the aim to produce commercial products. Zn containing wastes in the SR are represented by steelmaking dusts, wastes generated during hot dip galvanizing, wastes from copper production. The reasons for recycling Zn containing wastes are relatively high price of zinc (2240 USD/t in October 2014) and relatively large amount of input secondary raw material, what creates preconditions for its successful processing. Total annual amount of zinc in such wastes, in SR, is 5831 t worth of approximately 13 062 000 USD. Other advantages of recycling are: saving fees for landfilling of hazardous waste, possibility of using valuable compounds like Fe concentrate, Sn and Pb from sludge in ZnSO4 production and etc. Recycling of Zn containing wastes reduces environmental burden and leads to economic profit. Pyrometallurgical processing is economic only when processing more than 150 000 t/y, while hydrometallurgical processing already at 15 000 t/y, what is amount reachable in condition of SR. Therefore, the project is based on hydrometallurgical processing whose advantages are: high flexibility, using heterogeneous input material, lower investment and operating costs, high purity of products and no emissions.

The aim of the project is development of technology for recycling Zn containing wastes with aim to obtain commercial products ZnSO4.7H2O, ZnO, and electrolytic Zn. Because of some zinc bearing wastes contain also other valuable constituents as tin and lead, the next aims of project is reasonable recovery of commercial products containing tin and lead.