Gospodarka Surowcami Mineralnymi - Mineral Resources Management

This article takes an analysis of the mining M&As during 2000 and 2001 as a starting point for a discussion of the concentration of metal mining industries in general and in the gold and iron ore industries in particular. Potential influences on metal prices are also addressed. Article indicates the high pace ofconsolidation ofglobal mining and the increasing attractiveness of valuable assets ofmining companies, describes the major deals in 2000/200 I and provides detailed information about the most active companies: Billiton, BHP, Rio Tinto, Anglo de Beers. The author presents the structure of the gold industry and clarifies the relationships between the largest companies on the gold and iron markets. The influence of consolidation of the global mining industry on the metal market structure and the 2002 forecast is also considered.

Initiation of the principles of a market economy in Poland extracted a big effect on methods of settlement and application of mineral reserves, especially of economic reserves, which should be object of profitable mining. Last years in the columns of journals and among the specialist there was carried a discussion about valuation of reserves and range of changes. Treatment of results of inquiry should be disposed mines and the Treasury to verification of method of qualification and valuation of economic reserves. In order to obtain a valuation of reserves author of this article used the opinion of experts. The results of this method, described in the article, should persuade mines and the Ministry of the Treasury to verification of a method of valuation of economic reserves.

The paper presents empirical relationships for the determination ofyield and true density ofchars produced within the temperature range of coal plasticity. At this stage of carbonisation process, loose coal grains are transformed into agglomerated coke structure. The course of this transformation determines the properties of produced coke. Mass and true density changes ofcarbonised coal at this stage ofcarbonisation influence volume changes ofsolid material and, as a result, the porosity of obtained coal. Therefore the formulae concerning mass and volume changes within the temperature range ofcoal plasticity constitute an important element ofthe model ofcoking process. The first part of the paper contains the formulae referring to the mass and true density changes of mineral matter in carbonised coals. These formulae have been derived on the basis of the model of mineral components behaviour during carbonisation. The next part of the paper presents the formulae concerning the mass changes of organic matter in coal within the temperature range of its plasticity. On deriving the formulae it was assumed that, within the temperature range of plasticity, the organic matter could divided into two types, i.e. the organic matter of raw coal and the organic matter of resulting semi-coke. Moreover, the conversion of coal into semi-coke has been described by means of the Clp(t)- function. The parameters of this function have been determined on the basis of experimental data. The final part of the paper contains the formulae for calculation of yield and true density of chars produced within the temperature range of coal plasticity. The formulae presented in this paper arc based on laboratory research carried out under conditions similar to those in coking chamber (the rate of heating, the composition and pressure of gaseous atmosphere, the bulk density and the size of coal grains). For this reason the presented formulae can be used in the modelling of coking process on commercial scale.

Currently, coal is ranked among the three most important energy sources. Due to its abundant resources coal will play an important part in world energy balance in the years to come. One ofthe most interesting ways ofits conversion is the process of hydrogasification. However, the low coal reactivity with hydrogen constitutes a problem. Therefore, catalysts required for this process must be selected. The paper presents the results of kinetics examination of hard coal with high volatile matter contents. The first series ofexaminations involved comparison ofhydogasification kinetics for raw coal and for coal with reduced contents of ash and pyrite. In the former case much higher yields of hydrocarbons were observed, mainly due to a higher yield of methane. In the second series of examinations, coal with additions of pyrite, iron - oxide (Il} and elementary sulphur were observed to have a beneficial effect on the process of hydrogasification. In this case, the increase in the rate of reaction occurred at temperatures exceeding 1150 K. The iron - oxide (Il) alone was reported to have no influence on hydrogasification reaction. The other additives increased the yield ofmethane, not exerting any influence on other products ofhydrogasification process.

The review and the classification of mineral engineering processes course estimation indexes arc presented in article. The indexes arc based on the mass preservation law expressed by the dependencies between the average component concentrations in products. The index formula were treated as three-dimensional surfaces and it allowed to obtain better characteristic of indexes and to indicate the approximation direction of two-dimensional dependencies. The indexes with the best properties informational were pointed.

The Belchatów lignite open pit dewatering caused changes in water management of the area. Groundwater natural resources were changed. While groundwater storage were reduced, groundwater renewable resources were grown. For estimation the changes of ground water resources, ground water flow model was constructed representing the study area of about 2500 km2. The model simulation was performed for steady state condition for the period before drainage system has been put into operation and also for transient conditions as a result of 20-years mine dewatering with the mine water inflow ranged from 170--450 m3/min. The results obtained during simulation indicate that in the range of dewatering influence area effective infiltration from precipitation grows about 50%. Additional recharge of aquifer as a result of increase of water infiltration from water courses as well as artificial recharge from disposal site caused that the total renewable resources increased about 80%. After 20-years of dewatering, the total mine water inflow from groundwater renewable resources was 72. 7% and from groundwater storage was 27.3%.

Analysis of the intlucncc industrial waste site "Górka" on the groundwater quality in the disposal vicinity has been delineated. Pollutants from leaching of the industrial waste flow within natural joints and fissures and also artificial underground workings. Movement of the extremely alkaline solutes causes pollution ofthe groundwater in the Jurassic and Triassic aquifer. Progression of the leachate migration is potentially dangerous for water quality in Main Groundwater Basin (MGWB) 452 Chrzanów.

The Żuławy Wiślane groundwater structure includes three groundwater horizons: I - Pleistocene-Holocene, li -multiagc, IJI - Cretaceous. The I and Il horizons arc widespread although hydrogcological conditions in various parts of the Vistula River delta arc diversified. The Pleistocene-Holocene horizon is best developed in the Żuławy Gdańskie area (Main Groundwater Aquifer GZWP 112) and in the western part of the Żuławy Elblaskie one (Main Groundwater Aquifer GZWP 203). The Cretaceous aquifer occupies the eastern part of a large hydrogeological structure - the Gdańsk sub-trough which extends far beyond the Żuławy area. However, the practical importance of this aquifer is limited only to the Żuławy Gdańskie area (Main Groundwater Aquifer GZWP 111). The groundwater horizons are interconnected into the joint groundwater circulation system. The Żuławy Wiślane area is a regional drainage base for all groundwater horizons. The natural vertical flow directions towards the surface have been significantly disturbed due to intensive exploitation of aquifers. Most advanced changes were observed in Gdańsk and Elbląg areas where regional depressions of groundwater table reach a dozen ofmeters. The current rate of groundwater withdrawal reaches 122,000 m3/24 h. The main recharge for all the groundwater horizons in the study area comes from the lateral flow from the Kaszuby, Starogard and Iława lake districts. The direct infiltrational recharge from in the Żuławy Wiślane area is far limited due to impermeable cover of alluvial muds covering almost whole land and the well-developed melioration system which drains most ofmeteoric waters. The limiting factors for exploitation of groundwaters arc: hydrodynamic regime which precludes the lowering of groundwater table in Pleistocene-Holocene horizon below the bottom of impermeable beds and quality of groundwaters. In the vast areas of Żuławy Wiślane and Żuławy Elbląskie high concentrations of chlorides, iron, manganese and fluorides precludes the utilization of these outclassed waters. The modelling included three groundwater horizons in the Vistula River delta area. The internal boundaries of the model were based upon the morphology (margins of lake district uplands) and the sea shore. The calculations enabled the optimization of exploitation conditions for groundwater intakes in the whole groundwater structure and for regional units of the Żuławy area. Total groundwater resources of the Żuławy Wiślane area reach 212,880 m3/24 h.

The selection of groundwater aquifers which meet the qualitative and quantitative standards is an alternative solution to exploitation of surface waters of usually low quality and high susceptibility to pollution. However, the localization of such aquifers in particular hydrogeological structures is sometimes impossible. The common practical solution is the construction of infiltration wells which allows the artificial recharge of water horizons and, consequently, increases the groundwater resources. Detailed hydrogcological forecast of an intake operation gains still more practical importance. Analytical methods and/or more credible mathematical modelling arc common calculation procedures. The authors evaluated the accuracy of hydrogcological forecasts for double-well infiltrational intake localized close to the recharge boundary and perpendicular impermeable boundary. The results of analytical methods and mathematical modelling were compared for intakes under the conditions of confined and unconfined water table. Totally, 48 variants were considered, differing in assumed filtration parameters of groundwater horizons as well as technical and operational conditions of the intakes. For analytical calculations of the two interacting wells the formulae developed by the authors were applied. The accuracy of analytical calculation of intake discharge under the assumed boundary conditions is satisfactory, particularly for the confined water table (error: ± 1.0%). Under the unconfined flow conditions the maximum error rises to-6.0%. The errors for depression calculation are usually low (up to several per cent) in the immediate neighbourhood of the well but increase to about -20% towards the boundaries of depression cone.