Geomorphological Processes at the Industrial Sludge Landfill in Sered, Slovakia

The principal aim of the study is to identify the nature and causes of changes to the surface of a landfill body of waste from nickel production located in the industrial zone of the town of Sereď (Slovak Republic). This change is related to natural and anthropogenic geomorphological processes characteristic of the temperate zone of the northern hemisphere. The landfill is an accumulative anthropogenic form of relief, and its body is composed from an artefact-metallurgical sludge, which has specific properties. The landfill constitutes a strange shape of relief at the Danubian Plane, which attracts attention with its physiognomy and also with the black color of the material significantly. It formed during the 30-year-long existence of the nickel smelter plant (1963–1993) and remained in this location, until the present day, for another 28 years after the end of production. Since 1994, the landfill has been the property of a private company that mines sludge in order to obtain residual metals.

Life cycle impact assessment of metal production industries in Australia

Metal production industries are associated with positive economic benefits, however their activities are significantly resource and energy intensive, contributing to emission of pollutants and greenhouse gases to the environment. The balance between the economic inputs and environmental footprint of the metal production industries determines their contribution to sustainability. This work provides environmental impact assessment of the production of aluminium, copper, gold, iron and steel, lead, nickel and zinc, and considers their contribution to the economy. The emissions of selected representative industries in Australia were sourced from public national emission inventories and used as input parameters in the openLCA software. ReCiPe midpoint and endpoint hierarchist impact assessment methods were used to investigate the environmental impacts of the selected industries. The results indicate that lead, followed by aluminium and nickel production had the largest environmental impacts. The work further revealed the specific emissions for better control for each industry taking into consideration their relative environmental and economic impacts. For instance, adoption of renewable energy sources would significantly decrease the greenhouse gas emissions and the associated environmental impacts of the copper, zinc, gold, and iron and steel production industries. Improvement of sustainability of the production of lead would require further control of trace metal emissions, while for aluminium and nickel production, improved control of emissions of particles and the acidic gases SO2 and NOx.

The Nature of the Technosols on the Waste from Nickel Production

The aim of the study was to investigate the properties of the metallurgical sludge—waste from nickel production—on the landfill of a former nickel plant in Sereď, Slovakia, in relation to the technosols soil group. The sludge is a loose material which is a toxic industrial technological anthropogenic sediment of an unnatural black colour which originated from the crushing, washing, and leaching of poor iron–nickel lateritic ore in ammoniac solution and other caustics substances. The terrain reconnaissance enabled us to identify the points for the location of the probes. Here we dug seven probes and took 17 samples. In the samples the pH levels, the content of heavy metal and iron TOC, IC, C, and N, and the C:N ratio were determined. This study provides substantial empirical data on the properties of the metallurgical sludge. The results of the analyses clearly demonstrate that the sludge is a strongly alkaline material and contains toxic amounts of heavy metals (Cr, Ni). It is an artefact whose properties are unfavourable to living organisms and their communities. On the basis of the results of the probes analysis we identified the nature of the technosols on the given locality.

Removal of nickel from nickel production pulp simulators during gas-phase conversion

A new approach to Ni removal from simulators of dump waste product of the industrial waste purification of the wet gas-cleaning plant and the copper electrolysis workshop at the Copper Plant (Polar branch PJSC MMC «Norilsk Nickel») is proposed. The method is based on gas-phase treatment of waste product with NOХ, HNO3, or NH3 vapors, followed by dissolution of Ni salt in water. It has been found out that using nitrating media, containing HNO3 (vapor), NOX and H2O (vapor), allowed us to perform the effective leaching of nickel from the pulp simulator volume. A possible disadvantage of the method is a simultaneous leaching of considerable amounts of calcium and sulfur.

The use of low-temperature secondary energy resources using heat transformers in non-ferrous metallurgy

The concepts of developing efficient and reliable schemes for the use of waste heat of low-potential energy resources in heat transformers (HT) are considered. Examples of using HT in several non-ferrous metallurgy plants in Russia and Kazakhstan are given: the production of nickel, zinc and ferroalloys. In the case of nickel production, two schemes are proposed for consideration: for summer and winter modes. The main object of study is a nickel production scheme using a lithium bromide absorption chiller (AbCh). Recycled water is the main source of utilized low-grade waste heat for AbCh. The cold obtained in AbCh is necessary for the technological process. The basic parameters were calculated under various extreme conditions, the energy effect of the modernization of the circuit was estimated, and equipment was selected. Studies have shown the feasibility of introducing AbCh into circuits with a large amount of waste heat. Low-grade heat utilization of nickel production using heat pump unit (HPU) in winter allows to obtain heat energy for heating water from the heating network and raw water for feeding the boiler house of a thermal power plant.Another example of HT use is a heat pump unit (HPU) in the production of zinc and ferroalloys. HPU is designed to heat feed water before chemical water purification and at the same time “cool down” the circulating water, which is then used on a series of electrolysis, replacing purchased artesian water. In winter, the heat produced at HPU is used for heating, ventilation and hot water supply, which allows to dispense with the services of a third-party thermal power plant.