Mining wastes of the Russian North-West: microbiological prerequisites of reclamation

Russian North-West is the region with extremely high diversity of superficial mining wastes, deposited in form heaps and hills. These substrata are potentially dangerous for environments and. therefore, should be reclaimed. One of the most effective way of utilization of mineral wastes is to incorporate them to natural processes of revegetation and to initialize the priming of initial soil formation process. Thus, we have investigated microbial processes in very initial superficial ecosystems of numerous heaps of pre quaternary materials of former abandoned and recently explored quarries. The research question of this study: what groups of microorganisms we do have on the surface of mining mineral wastes and are we able to qualify their role in further recycling of mineral waste to natural processes, including pedogenesis and ecogenesis of terrestrial ecosystems. The great variation of taxonomy composition of microbiome composition was revealed. At the same time, some phylums of microorganisms were dominant in all revegetated heaps investigated - Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Chloroflexia, Verrucomicrobia. They could be considered as a core components of very initial soil microbiome. Primary data have showed the increasing of microbial biodiversity with timing rate of waste exposure on surface.

Use of the O2-Thiosemicarbazide System, for the Leaching of: Gold and Copper from WEEE & Silver Contained in Mining Wastes

Environmental pollution today is a latent risk for humanity, here the need to recycle waste of all kinds. This work is related to the kinetic study of the leaching of gold and copper contained in waste electrical and electronic equipment (WEEE) and silver contained in mining wastes (MW), using the O2-thiosemicarbazide system. The results obtained show that this non-toxic leaching system is adequate for the leaching of said metals. Reaction orders were found ranging from 0 (Cu), 0.93 (Ag), and 2.01 (Au) for the effect of the reagent concentration and maximum recoveries of 77.7% (Cu), 95.8% (Au), and 60% (Ag) were obtained. Likewise, the activation energies found show that the leaching of WEEE is controlled by diffusion (Cu Ea = 9.06 and Au Ea = 18.25 kJ/Kmol), while the leaching of MW (Ea = 45.55 kJ/Kmol) is controlled by the chemical reaction. For the case of stirring rate, it was found a low effect and only particles from WEEE and MW must be suspended in solution to proceed with the leaching. The pH has effect only at values above 8, and finally, for the case of MW, the O2 partial pressure has a market effect, going the Ag leaching from 33% at 0.2 atm up to 60% at a 1 atm.

Management of mining wastes through their transformation into useful sorbent

Abstract Every year a few hundred million or so tons of industrial waste are generated all over Europe. A considerable share is attributable to exploratory wastes from the mining sector and combustion byproducts. The process of their reprocessing and utilization fits into the following rules subject to intensive development, viz.: zero waste economy (Zero Waste Europe), effective use of resources (Resource Efficient Europe) as well as closed-circuit economy (Circular Economy). The article shows some research results to corroborate the concept of industrial waste processing of carbonaceous shales into sorbent materials. The applied process of carbonaceous shale calcination led to the obtaining of a material containing metakaolinite, then used in the synthesis of zeolites. The specific surface of the sorbent obtained in the aforesaid way exceeded 100 m2/g.

Mine Waste-Based Next Generation Bricks: A Case Study of Iron Ore Tailings, Red Mudand GGBS Utilization in Bricks

Utilization of mine wastes as a building material in the construction industry surmises to environmental and sustainable concepts in civil engineering.The potential environmental threat posed by mining wastes, as well as a growing societal awareness of the need to effectively treat mining wastes, has elevated the subject importance.The present research proposes a method of producing bricks that is both cost effective and environmentally benign. The research is based on the geopolymerization, known to save energy by obviating high-temperature kiln firing and lowering greenhouse gas emissions. The methodology encompasses the mixing of red mud and iron ore tailings in the range of 90% to 50% with a decrement of 10% with GGBS in the range of 10% to 50% with an increment of 10%. The raw materials and the developed composites have been tested as per Indian and ASTM standards.In addition to tests pertaining to the physical and mechanical properties, XRF, XRD, and SEM tests have been performed for examining various related issues. Based on the result analysis, the compressive strength values showed noticeable differences in case of IOT and red mud bricks with IOT-based bricks showing better compressive strengths.

Quantification of Potentially Toxic Elements in Degraded Mining Soils and Medicinal Plants: A Case Study of Indus Kohistan Region Northern Pakistan

In recent years, a series of environmental and ecological problems have occurred due to enhanced anthropogenic disturbances for precious minerals mining. Traditional medicines have become an important pillar in national homeopathic treatment system especially in mountainous environment of developing countries. The current study investigates the level of potentially toxic elements ( PTEs ) contamination in degraded mining soil and medicinal plants along the mafic-ultramafic rocks in the Kohistan region. Soil samples and medicinal plant species were collected from the degraded mining area and were screened for PTEs (Pb, Cr, Ni, Mn, Zn, and Cd) using atomic absorption spectrometry. Various pollution indices were used for PTEs such as contamination factor (CF), pollution load index (PLI) and translocation factor (TF) in degraded mining soil and medicinal plants. The mean concentration of PTEs found in soil were in order of Mn>Ni>Cr >Pb>Zn>Cd, while in medicinal plants were Pb>Cr>Mn>Ni>Zn>Cd. Highest bioaccumulation was observed in Ajuga bracteosa (Cr=349 mg kg –1 ), Phlomis bracteosa (Pb=335 mg kg –1 ), Chenopodium ambrosioides (Mn = 304.3 mg kg –1 ), Isatis costata (Ni=169 mg kg –1 ), Ajuga parviflora (Zn = 38.4 mg kg –1 ) and Salvia moorcoftiana (Cd=11 mg kg –1 ). Furthermore, the concentrations of PTEs were significantly higher ( p <0.001) in degraded mining soil and medicinal plants than the reference site, which may be attributed to the mining and open dumping of mining wastes. The present study revealed that chromite mining and open dumping of mining wastes can cause serious environmental problem in the study area. Furthermore, medicinal plants grown in degraded mining soil may pose risk to the local inhabitants as most of the people consume these plants for various health problems.