Technische Eignung und wirtschaftliche Betrachtung der Aufarbeitung komplexer Sekundärrohstoffe

Research output: ThesisMaster's Thesis

Abstract

The number of recycling processes for the treatment of secondary raw materials increased during the last decades due to upcoming environmental legislations as well as the need for high recycling rates which come along with the request for sustainable production. In most of them only one valuable metal is recovered. This causes that the economic of the process is highly depended on the price for the metal and the energy price. In awareness of the just mentioned facts, this master thesis considers a process wherein more than one metal can be recycled. Another important aspect is the quality of the main product zinc oxide. The investigated method is a treatment on an inductively heated metal bath, in this case an iron bath, which is the base for the pyrometallurgical treatment of zinc containing raw materials. Such typical complex wastes arise from the ferrous- as well as the nonferrous-metallurgy, for instance dusts from copper secondary industry, electric arc furnace dusts from carbon steel production, neutral leaching residues from zinc industry and the waelz slag. This gives an interesting assortment of available residues from metal producing industries. These secondary raw materials came on the one hand from different industries and on the other hand from pyro- as well as hydrometallurgical processes. In the special case of the waelzslag, a material which passed already a recycling step is the matter of investigation. As a first step it was necessary to perform intensive investigations in the characterization of the secondary raw material, which shows the morphologic phases, the meltability, the reduction behaviour and the needed additives. Based on the charaterization, thermodynamic calculations and the chemical analysis a mass- and an energy-balance for the treatment on an inductive heated metal bath were created. Furthermore a description for the energy consumption is given, which includes the covering of the losses, the warm-up of the feedstock as well as the energy for the chemical reactions. Based on the mass- and energy-balance a view on the economy of the described process was carried out. This was based on information from process development companies, currently carried out projects just as finished ones and literature surveys. The treatment seems to be economical in case of a suggestive process control, the recycling of more than one metal and a high quality product without increasing the energy demand and investment costs. Especially the high zinc bearing EAF-dusts and dusts from copper secondary industry are showing a high potential.

Details

Translated title of the contributionTechnical applicability and economic outlook on the treatment of complex secondary raw materials
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date18 Dec 2009
Publication statusPublished - 2009