Geochemistry, petrology and evolutionary computations in the service of archaeology: restoration of the historical smelting process at the Katowice–Szopienice site

Acknowledgments This study was was supported by NCN 53 grant No. 2014/13/B/ST10/02403, entitled “Zinc and lead metallurgical slags—testing ground for investigation of behaviour of potentially toxic elements in the crystal phase structures and their interaction with environment” given to AG and supported by the grant of Centre for Polar Studies, University of Silesia, Poland—The Leading National Research Centre (KNOW) in Earth Sciences 2014-2018 given to RWActivity at the smelting plant at Katowice–Szopienice dates back to the nineteenth century. Currently, the Museum of Zinc has been funded at the site. Unfortunately, as a result of unrest during both World Wars, all technological descriptions were lost. Three historically described samples were provided by Museum of Zinc and additional slag and lining samples were collected directly from the furnace. “Enriched ore” is dominated by ZnS (89.5%) as sphalerite and wurtzite accompanied by gangue minerals. “Roasted ore” is composed mainly of zincite (74%) resulting from the oxidation of ZnS. Study has proved that “roasted ore with coke” sample description is inappropriate. It is zinc depleted and enriched in Si (22.93 wt.%), Al (9.16 wt.%), C (9.66 wt.%) and its phase composition suggest that it contains recycled lining material and coke. Such characteristics place sample as additions used for smelting process. Advanced mathematical tool, the differential evolution algorithm, was used for restoration of smelting process at the site. Algorithm proved great usefulness by providing low dispersed results for calculated compositions of loss on smelting (mainly yield) with the fitting error reduced down to 1.19 wt.%. Loss on smelting composition was dominated by Zn (41.40 wt.%), Si (9.67 wt.%) and C (9.50 wt.%). Proportion of roasted ore to addition in smelting process was estimated as 1:1.27 and loss on smelting share from batch was 62%. Geochemistry and petrology have provided rich qualitative information about the samples and smelting process, but in combination with evolutionary computations, high-quality quantitative data were obtained

The pyrolytic-plasma method and the device for the utilization of hazardous waste containing organic compounds

This paper is focused on the new method of waste processing. The waste, including hazardous waste, contain organic compounds. The method consists in two main processes: the pyrolysis of waste and the oxidation of the pyrolytic gas with a use of non-equilibrium plasma. The practical implementation of the method requires the design, construction and testing of the new device in large laboratory scale. The experiments were carried out for the two kinds of waste: polyethylene as a model waste and the electronic waste as a real waste. The process of polyethylene decomposition showed that the operation of the device is correct because 99.74% of carbon moles contained in the PE samples was detected in the gas after the process. Thus, the PE samples practically were pyrolyzed completely to hydrocarbons, which were completely oxidized in the plasma reactor. It turned out that the device is useful for decomposition of the electronic waste. The conditions in the plasma reactor during the oxidation process of the pyrolysis products did not promote the formation of PCDD/Fs despite the presence of the oxidizing conditions. An important parameter determining the efficiency of the oxidation of the pyrolysis products is gas temperature in the plasma reactor.Web of Science31829028