This article presents a concept method which aids the forecasting of the reclamation cost in post- rock mining areas. The method may also prove useful in estimating the investment profitability of a mining operation at its planning stage as well as managing a potential Reserve Fund to cover future activities, such as land reclamation. The development of the method consisted in defining a set of basic/typical land reclamation directions and the typical structure of reclamation operations/works, which are based on “statistically stable” values. The estimations included the distribution of the probable cost of these works with respect to the reclamation direction and were calculated on the basis of the analyzed current price lists and historical land reclamation projects. The article proposes a method for estimating the cost structure of multi-directional projects by combining the basic directions. The changeability and predictability of various land reclamation solutions was analyzed in terms of fuzzy logic. A price list was developed, which included unit costs for separate types of reclamation works, independent of their type and scale. The assumed optimal measure involved comparing the cost of individual types of operations to the surface of the reclamation area. As an example, the method was also applied to hypothetical data from a clastic rock mine with a surface of 20 ha, and for the forest, agricultural and forest-agricultural reclamation directions. The forest-agricultural reclamation directions was presented in the proportions of 0.3:0.7.
A study was undertaken to investigate the effects of crumb rubber on the strength and mechanical behaviour of Rubberized cement soil (RCS). In the present investigation, 26 groups of soil samples were prepared at five different percentages of crumb rubber content, four different percentages of cement content and two different finenesses of crumb rubber particle. Compressive strength tests were carried out at the curing age of 7 days, 14 days, 28 days and 90 days. The test results indicated that the inclusion of crumb rubber within cement soil leads to a decrease in the compressive strength and stiffness and improves the cement soil’s brittle behaviour to a more ductile one. A reduction of up to 31% in the compressive strength happened in the 20% crumb content group. The compressive strength increases with the increase in the cement content. And the enlargement of cement content is more efficient at low cement content.
The problem related to the management of post reclamation dusts generated in the reclamation process of waste moulding sands with
organic binders is presented in the hereby paper. Waste materials generated in this process are products hazardous for the environment and
should be utilised. The prototype stand for the utilisation of this dangerous material in its co-burning with coal was developed and patented
in AGH in Krakow. The stand was installed in one of the domestic casting houses. As the utilisation result the transformed waste product
is obtained and its management in the production of ceramic materials constitutes the subject of the presented publication.
“Wartowice” tailings pond was closed in 1989, resulting in 232,4 ha tailings pile requiring reclamation. The major problem is heavy metals presence and poor nutrient conditions and physicochemical structure of soil which disturbs the plants development. In order to assess the real condition of studied area the complete biological characteristic has been done. The physicochemical conditions were assessed altogether with phytosociological, microbiological and toxicological studies of deposits. We recorded only 27 species of vascular plants belonging to 15 families on the tailings pond of which 5 belong to Rosaceae, 4 to Asteraceae and 3 to Poaceae and Saliceae. Species inhabiting the tailings depended on their dispersal capacity, metal tolerance and rhizome strategy. Microbiological analyses revealed the low number of bacteria and fungi on the tailings pond, apart from the small uplift area where the plants were indentified. Bacteria identified on the tailings pond were classified to 8 genera. The low number of bacteria suggests the lack of nutrients which affects the development of soil microflora. Toxicity tests showed that post-flotation sludge is not toxic to microorganisms because of its high pH. Some plants, such as lucerne could even influence positively the microorganisms development what has been proved in our studies. The tailings toxicity was higher towards producers, where Secale cereale appeared to be the most sensitive species. Amendment with topsoil from adjacent areas can influence positively the phytotoxic properties of tailings and enrich them into native seeds.
The cumulative results of investigations of the possibility of using the reclaimed materials after the mechanical, thermal or
mechanical-thermal reclamation for making cores by means of the blowing method in the alkaline CO2 technology, are
presented in the paper. Three kinds of spent sands: with furfuryl resin, bentonite and alkaline phenolic resin, obtained from
the foundry, were subjected to three kinds of reclamation: mechanical, thermal and combined mechanical-thermal, applying
for this aim adequate experimental devices. The obtained reclaims were assessed with regard to the degree of the matrix
liberation from the determined binding material. Reclaims of moulding sands with binders of the form of resin were assessed
with regard to ignition loss values and pH reaction, while reclaims of moulding sands with bentonite with regard to the
residual clay content and pH value. In all cases the results of the performed sieve analyses were estimated and the average
characteristic diameter dl was determined. The reclaimed matrix was applied as a full substitute of the fresh high-silica sand in typical
procedures of preparing core sands used for making shaped samples for bending strength investigations, Rg
u
.
Presented are results of a research on usability of an innovative reclamation process of microwave-hardened moulding sands containing
water-glass, combined with activation of binder. After each subsequent stage of reclamation, quality of the reclaimed material was
determined on the grounds of measurements of permeability and results of screen analysis. The reclaimed material was next used again to
prepare new moulding sand. The sandmix based on high-silica sand prepared with water-glass grade 145, was subject to the following
cyclical treatment operations: mixing components, consolidation, microwave hardening, cooling, heating the mould up to 800 °C, cooling
to ambient temperature, mechanical reclamation dry and wet. It was found that the used-up and reclaimed sandmix containing water-glass
is susceptible to the applied activation process of thermally reacted film of binder and, in addition, it maintains good quality and
technological properties of high-silica base. Observations of surfaces of reclaimed high-silica grains with activated film of reacted
inorganic binder were carried-out using a scanning microscope. Thanks to properly selected reclamation parameters, the high-silica base
can be reused even five times, thus reducing demand for fresh aggregate and inorganic binder.
The paper, especially dealt with problems of reclamation of used furan sand, carried out in new, vibratory sand reclamation unit REGMAS
developed by researches from AGH-University of Science and Technology, Faculty of Foundry Engineering in Cracow (Poland).
Functional characteristics of reclamation unit as well as the results of reclamation of used sand with furfuryl resin are discussed in the
paper. The quality of reclaim was tested by means of the LOI and pH value, dust content in the reclaim and at least by the the quality of
the castings produced in moulds prepared with the use of reclaimed matrix.
The article discusses the problem of the supply of a by-product, which is synthetic gypsum produced as a result of flue gas desulphurization in conventional power plants. The state of production and forecast for the future are presented. Currently, synthetic gypsum is almost entirely used as a raw material in the gypsum products plant located in the immediate vicinity of the power plant. Since the mid-1990s, in Poland, an increase in the production of synthetic gypsum associated with the construction of a flue gas desulphurization installation in Polish conventional power plants has been observed. In the near future, the upward trend will continue in connection with the construction of new coal units in power plants. Significant surpluses of this raw material will appear on the market, which will not be used on an ongoing basis in the production of gypsum components. However, due to the EU’s restrictive policy towards energy based on coal and lignite, within the next few decades, the share of conventional power plants in energy production will be gradually reduced. As a consequence, the supply of synthetic gypsum will also gradually decrease. Therefore, it is advisable to properly store the surplus of this raw material so that it can be used in the future. Taking this into account, it is already necessary to prepare methods for storing the expected surpluses of synthetic gypsum. For this purpose, post-mining open pits are particularly suitable, especially in mines of rock raw materials. The article proposes a legal path enabling the post-mining open pits to be transformed into a anthropogenic gypsum deposit.
The article presents the directions of foundry waste management, mainly used for spent foundry sands (SFS) and dust after the reclamation of this waste. An important aspect of environmental protection in foundry production is the reduction of the amount of generated waste as a result of SFS regeneration. The advantage is the reuse of waste, which reduces the costs of raw materials purchase and environmental fees for landfilling. Non -recycled spent foundry sands can be used in other industries. SFS is most often used in road and construction industries as well as inert material in closed mines (Smoluchowska and Zgut 2005; Bany-Kowalska 2006). An interesting direction of using SFS is its application in gardening and agriculture. The article presents the advantages and disadvantages of such use. It was found that spent foundry sands can be useful for the production of soil mixtures for many agricultural and horticultural applications. Due to the possibility of environmental pollution with heavy metals and organic compounds, such an application is recommended for the so-called green sands, i.e. SFS with mineral binders. In addition, an innovative solution for the energy use of dusts after spent foundry sands reclamation with organic binders has been discussed and proposed by some researchers. It was shown that dust from reclaimed SFS with organic binders can be used as an alternative fuel and raw material in cement kilns, due to the high percentage of organic substances which determine their calorific value and silica.
Open pit mining has severe environmental impacts on the environment of mining region. Mined land reclamation procedure in open pit mining contains numerous activities in order to prevent, monitor, control reduce environmental impacts of a project from exploration stage to exploitation, to mine closure and beyond. After mine closure, a permanent Post Mining Land Use (PMLU) should be implemented as an appropriate choice for use of different sections of mined land in an open pit mine. Mined land in open pit mining comprise different sections as pit(s), waste dump(s), tailing pond(s), roads, areas for on site facilities and free land zones which are not mined. The selected PMLU for each section of mined land as the most appropriate alternative based on the different points of view is presented as Optimum Post Mining Land Use (OPMLU). OPMLU for each section of mined land and the specifications of mine site are the most decisive parameters which affect the quality and volume of mine closure procedure, reclamation process and their costs. Furthermore, to define Ultimate Pit Limit (UPL) in open pit mining, consideration of mine closure and reclamation costs is essential as other costs of a mining project. Therefore, defining OPMLU for each section of mined land is essential within planning phase of an open pit mining project. In this paper the applicable alternatives of PMLU, the effective criteria, attributes and sub-attributes for defining OPMLU are presented for pit area amongst different sections of mined land. Pit area amongst different sections of mined land has more significant effects on the adjacent environment and also on defining OPMLU for the other sections of mined land. As there are several alternatives of PMLU, several criteria, attributes and sub-attributes for defining OPMLU, Multi Attribute Decision Making (MADM) methods are efficient techniques to define OPMLU for pit area. Fuzzy sets use a spectrum of numbers instead of using absolute numbers. As well, the nature of the effective parameters for defining OPMLU is same as Fuzzy numbers including incremental changes without definite limits thus the use of Fuzzy MADM modeling can produce more reliable results than the other techniques. As pair-wise comparisons and judgments through Fuzzy numbers have proper consistency with the nature of the effective parameters for defining OPMLU accordingly, a model is developed to attain OPMLU for pit area through Fuzzy Analytical Hierarchy Processing (FAHP). As a case study the model was implemented in Sungun copper mine in Northwest of Iran. Lumber production was defined as OPMLU for the pit area in this mine. It is finally concluded that using the developed model, OPMLU is defined for pit area as a key parameter to estimate reclamation costs in planning phase of an open pit mining project.
There was done an inventarization of 41 coal mining dumping grounds, gathering waste material from 27 mines. Considering the fact, that five mines belong to multi-motion plants the research comprised 32 hard coal deposits. Source data with localization of particular dumps have been obtained from archival materials from the mines and municipalities, in the boundaries where the dumps occur as well as free accessible published materials (books, scientific papers). The data have been verified, in the beginning on the basis of topographical maps, orthophotomaps and aerial photographs and then, after vision done during field works they have been drawn on the topographic base, what resulted in creating the map of post-mining dumping grounds. Valorisation of coal mining waste dumps, using already repeatedly presented method, included defining of: name of the dump, coal mine from where the wastes come from, state of the dump, surface of the dump, type of technical and biological reclamation, accessibility of the object, possibilities of recovery of coal and the results have been drawn on the map. On the basis of collected and elaborated data there was done an attempt of defining of potential possibilities of recovery of coal from the dumps and connecting of coal quality in exploited deposits and coal content in waste material. The results showed that in spite of initial information that the majority of the dumps comprise potential objects of coal recovery of coal from waste material, eventually only in some cases (thirteen objects) the recovery seems to be economically justified.
The analysis of after reclamation dusts generated during the reclamation treatment of test portions of two kinds of polydispersive material in the Regmas device, is presented in the hereby paper. For the comparative purpose the fresh moulding sand marked as quartz sand „Sibelco” –1K 0.40/0.32/0.20, J88, >14000C, WK = 1.20 (acc. PN-83/H-11077), as well as the spent moulding sand, which was previously subjected to the primary reclamation and to dedusting, were used. Conditions of the process treatment were forced by the frequency of supplying the vibratory drive motors being successively 40, 50 and 60Hz for 5, 10 and 15 min. and by causing a diversified material flow through the functional system of the device (charging hopper, abrasive chamber acting as a buffer space). Two states of the process treatment, when a material was flowing through the chamber, were applied. In the first one, an intergranular surface abrasion of grains occurred as a result of the granular material circulation in the chamber forced by the vibratory drive. In the second one, the forced material flow was performed in the presence of crushing elements (steel balls), additionally introduced into the abrasive chamber. Analyses of the device influence were performed by determinations of the amount of dusts separated in the pneumatic classifier and analysis of their grain sizes by means of Analysette 22NanoTec.