Ore and non-ore mineralization in cracks filled with hydrocarbons in the dark grey Upper-Devonian limestone has been found in the Józefka quarry of Upper Devonian limestone and dolomite near the Górno village near Kielce at Holy Cross Mts. Poland. Hydrocarbons in the liquid form and iron and copper sulphides appears hear in the fault zone as joints filling. The wall rocks are impregnated by hydrocarbons giving them black color. Hydrocarbon impregnations appears also following the bedding planes The coexistence of ore mineralization and hydrocarbon suggests their common origin and migration from deep-seated sources, that may be the Silurian Ordovician or Lower to Middle Devonian black shales. The metallic-hydrocarbon compounds were suggested as metals carrier.

Ore and non-ore mineralization in cracks filled with hydrocarbons in the dark grey Upper-Devonian limestone has been found in the Józefka quarry of Upper Devonian limestone and dolomite near the Górno village near Kielce at Holy Cross Mts. Poland. Hydrocarbons in the liquid form and iron and copper sulphides appears hear in the fault zone as joints filling. The wall rocks are spotty impregnated by hydrocarbons giving them black color. Hydrocarbon impregnations appears also following the bedding planes The coexistence of ore mineralization and hydrocarbon suggests their common origin and migration from deep-seated sources, that may be the Silurian Ordovician or Lower to Middle Devonian black shales. The metallic-hydrocarbon compounds were suggested as metals carrier.

The article analyzes the present state of the phosphate raw material base to meet Ukrainian chemical enterprises’ needs. In Ukraine, a number of complex apatite and phosphorite deposits have been explored. Their exploitation can lead to a complete supply of Ukrainian chemical enterprises with raw materials and can partly reduce the amount of expensive imported phosphate mineral fertilizers. At present, the following deposits, where apatite is connected with other useful components, are prepared for exploitation: Stremyhorod, Fedorivka, Novopoltavka, Kropyvna and others. The advantage of the development of these deposits is the possibility to extract apatite along with the production of rare earth concentrates, ilmenite, titanomagnetite, as well as feldspars, olivine, pyroxenes, mica and others which will significantly increase the profitability of the deposits development.

The alternative to apatite-containing deposits in Ukraine can be sedimentary deposits of nodule, granular and mixed type phosphorites. Phosphorite deposits can be used mainly for the production of phosphorite and limestone flour. Considerable resources of granular phosphorites have been discovered in Volyn-Podillia and Dnieper-Donetsk which are considered to have a various agricultural effect. They are environmentally friendly ores without impurity which prevents plants from cesium, strontium and reduces nitrates in the soil. Arranging the exploration of phosphorite ores in certain parts of Volyn-Podillia basin and Dnieper-Donets Rift is recommended.

The article concerns investigations over benefits of application of HRC devices into sulphide copper ore processing plant. High pressure comminution appears to be very effective technology in hard ore processing circuits, especially in terms of energy consumption. This can be particularly observed in downstream grinding and beneficiation operations. A series of pilot-scale crushing tests in HRC roller press for various levels of operating pressure, were performed. HRC crushing effectiveness along with downstream grinding process course for each crushing product were also under analysis. The investigations were supplemented by analysis of flotation process effectiveness and impact of the process of high-pressure comminution on environment (dust emission). The results of investigation show that operating pressure level influences the obtained comminution results (comminution degree, yield of finest particle size fractions). The grinding effectiveness, measured through production of the finest particle size fractions was significantly influenced by the operating pressure. The results show that higher values of operating pressure (4.0 and 4.5 N/mm2) are not as efficient within this scope as the pressure 3.5 N/mm2. Dust emission is also correlated with the operating pressure value.

Reconciliation between two copper ore mines transferred ore from one mine to another for processing in enrichment plants generated the need to regularly study the amount and composition of the ore on the conveyor connecting these two mines. To ensure the objectivity of the study, taking composite samples and their analysis was entrusted to a specialized outside laboratory. However, the managing staff of both mines still have doubts whether sampling results reflect correctly content of transported ore especially when the fed is highly variable. In order to investigate how the relatively low sampling rate affects the accuracy and precision of the measurement, the article investigates the hypothetical situation on the linking conveyor with the ore having extremely differentiated mineralization: 80% of almost barren rock (below 0.7% Cu) and 20% of the richly mineralized shale (around 10% Cu). Such ore occurs in some areas of the mine, from which it is fed onto a connecting conveyor. Through simulation techniques it was examined how the frequency of sampling can influence the distribution of the pooled sample results. It turned out that for 16 randomly selected samples in the following 15 minutes time intervals of a working shift, the spread of results around the simulated value is very large. A satisfactory accuracy level for the estimations of mean Cu content in the transported ore is achieved when the samples are collected at 30-second intervals. Only with sampling frequency close to on-line scanner parameters the probability of obtaining estimations with deviation exceeding 10% drops to the level of 2%. In the case of extremely differentiated ore doubts about confidence in the described measurements are fully confirmed, because with over 50% probability a single measurement could be deviated by 50% up and down from the true value.

The separation or beneficiation processes are conducted in many devices and concern many various types of minerals and raw materials. The aim of conducting these processes is always to achieve the best possible results allowing as much of the useful component as possible to be obtained by maintaining reasonable costs of the process. Therefore, it is important to have the possibility to monitor the process effects and to have efficient tools to evaluate the course of it. Generally, the ore’s ability to partition into concentrate and tailings is called its efficiency, upgradeability etc. It can be said that there is no unambiguous measure of upgradeability and there are many factors in use which enable to evaluate it qualitatively. Among them are such commonly known parameters as: recovery, losses, yield, upgrading ratio and many others. They are based on three principal parameters that is the average content of the useful component α, the contents of this component in concentrate β and the contents of this component in tailings ϑ. For a given ore (assuming that α = constant), the multi-product separation results can be treated as points of a trajectory located on the surface of factor w in a three dimensional space (β, ϑ, w). The course of the trajectory depends on the ore petrographic and mineralogical properties preparation for the process. For these reasons, searching for optimal (potential) possibilities of the ore is relative, which is presented in the example of Halbich, Fuerstenau and Madej upgrading curves. Such curves are efficient tools to evaluate the course of a separation (beneficiation) process and each of their types allow the effects to be shown in different perspective. Apart from this, they allow also the optimal feed conditions to conduct a certain process with aim of achieving the expected results to be found. Furthermore, the effect of the ore preparation on the flotation results, on the sum of recoveries of the useful component in concentrate and residual recovery in tailings is presented in the paper. The results indicated that any additional contamination of concentrate should be taken into account during the organization of the flotation process. In this way, the results of fractionated flotation have much valuable information to establish the course of the process.

At present, with the increase of production capacity and the promotion of production, the reserves

of most mining enterprises under the original industrial indexes are rapidly consumed, and the full

use of low-grade resources is getting more and more attention. If mining enterprises want to make

full use of low-grade resources simultaneously and obtain good economic benefits to strengthening

the analysis and management of costs is necessary. For metal underground mines, with the gradual

implementation of exploration and mining projects, capital investment and labor consumption are

dynamic and increase cumulatively in stages. Consequently, in the evaluation of ore value, we should

proceed from a series of processes such as: exploration, mining, processing and the smelting of

geological resources, and then study the resources increment in different stages of production and the

processing. To achieve a phased assessment of the ore value and fine evaluation of the cost, based on

the value chain theory and referring to the modeling method of computer integrated manufacturing

open system architecture (CIMOSA), the analysis framework of gold mining enterprise value chain is

established based on the value chain theory from the three dimensions of value-added activities, value

subjects and value carriers. A value chain model using ore flow as the carrying body is built based on

Petri nets. With the CPN Tools emulation tool, the cycle simulation of the model is carry out by the

colored Petri nets, which contain a hierarchical structure. Taking a large-scale gold mining enterprise

as an example, the value chain model is quantified to simulate the ore value formation, flow, transmission

and implementation process. By analyzing the results of the simulation, the ore value at different

production stages is evaluated dynamically, and the cost is similarly analyzed in stages, which can improve mining enterprise cost management, promote the application of computer modeling and

simulation technology in mine engineering, more accurately evaluate the economic feasibility of ore

utilization, and provide the basis for the value evaluation and effective utilization of low-grade ores.

The article presents the results of plasma vitrification of solid remnants from thermal waste treatment with and without the addition of a carbonate fraction obtained from lead-zinc ore flotation. The substrates used in the research were slags and ashes from medical waste treatment, incineration of municipal waste, sewage sludge as well as hazardous and industrial wastes.

The plasma treatment resulted in acquiring products of different quality depending on the processed substrate. Most of the obtained products were of vitreous and homogenic build. Treatment of remnants from incineration of hazardous and industrial wastes resulted in obtaining heterogeneous and rough surfaced products. A 20% share of the carbonate fraction enabled the obtaining of a vitrified product with a glassy surface and fracture. Hardness of the obtained products was rated in Mohs scale and ranged from 6 to 6,5. Leaching tests showed a decrease in heavy metal concentration in the leachates from vitrificates with the addition of carbonate fraction compared to the ones with it.

In this paper are presented results of study fusion characteristics of the biomass ashes from the hydrolyzed lignin and the ashes from the coke breeze. The hydrolyzed lignin ashes were compared with the coke breeze ashes i.e. with a fossil fuel. These ashes were prepared in muffle furnace at the temperature of 550°C (hydrolyzed lignin) and 850°C (coke breeze). Biomass (the hydrolyzed lignin) represents the new fuels for sintering process and an attractive way to decrease CO2 emissions from the energy production. The characterization methods were the following: standard fuel characterization analyses, chemical and mineralogical composition of the ashes and phase analyses of the ashes of biomass and the coke breeze. These ashes were prepared by the same method. Characterisation of the ashes samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline and amorphous phases in each of the ash samples were carried out using the Rietveld method. The dominant phase of the ash from the coke breeze was mullite (Al6Si2O13). SiO2 is the dominant phase of the ash from the hydrolyzed lignin.

The contemporary underground mining of raw minerals is more and more associated with geological and mining software packages which support the work of designers from the moment of the exploration of a deposit, determination of its size and quality, geological, hydrogeological and tectonic conditions, by planning the development and cutting of the deposit. Production planning is one of the most important activities carried out in the course of a mining project, because it allows to set specific production results of a mine in relation to a time unit, and then allows for a verification of the degree of completion of the assumed plan. At present, computer-aided design is applicable to daily or long-term output planning taking deposit, qualitative, quantitative and cost constraints into account. In the article, selected forms of ore deposits were presented. On the basis of several dozen boreholes up to 300m in length, an exemplary fragment of the ore cutting model using computer-aided design of mining works was presented. By using modern computer software - ABB MineScape with modular construction, the possibilities of improving the process of development of future exploitation areas have been determined. In particular, the arrangement of boreholes, based on which ones the cross sections were made with, present the exemplary lithostratigraphic thickness of layers, including the location of discontinuous deformations in the form of faults, and an ore bearing zone. For the block model, resources with priority for metal N o. 1 and 2 were calculated. I n the last section of the article, the cutting idea for a shallow ore deposit has been presented. The degree of effective use of the deposit has been analysed for the room and pillar mining method.

The analysis of changes in the mechanical properties of wooden mining cribs under the influence of different types of exploitation loads is the question for which deals with many domestic and abroad research centers deal with. High The high interest in this subject results from the increase of the conducted depth exploitation, which contributes to the increase in both the vertical pres-sure and the complexity of geological – mining conditions and in- the intensification of natural hazards. Another reason is the tendency of decreasing the thickness of the exploited ores deposits. Wooden crib support is used Both both in underground ore, hard coal and salt mining is used wooden crib support. Mining cribs with various configurations are especially useful for the reinforcement of excavations workings behind the front and for further strengthen of the crossings. In particular, additional reinforcement support in the form of wooden cribs (pile supporting), which shall be left empty or filled with waste rock is applied in the ore mining in places where found extended rooms or drifts are found or in places with degraded roof conditions, applies additional reinforcement support in the form of wooden cribs (pile supporting), which shall be left empty or filled with waste rock. During underground ex-ploitation is produced waste Waste rock, which comes from the access, prepar-atory excavations and from ongoing field of exploitation is produced during underground exploitation. In the case of the underground exploitation of cop-per ore, waste rock is used to fill voids after exploitation as rock stowing. It is also used for filling mining wooden cribs, as an artificial support and for harder transportation roads. This paper presents the results of the laboratory strength tests performed on models of four-point timber cribs, built with beams set horizontally, at the ge-ometrical scale of 1:10. In the laboratory research Research wooden cribs models with size 200 × 200 × 200 mm and 100 × 100 × 100 mm were used in the laboratory. The paper describes the maximum loading capacity of the cribs consisted consisting only of beams and filled with waste rocks. In addition, a vertical and appropriate strain of cribs at maximum force was shown. On the basis of laboratory research it was found that the use of the same number of timbers and the management of waste rocks, the filling of the four-point cribs with the waste rocks allowed several times to increase its support to be increased several times.

The article describes the method of controlling the recovered grade based on measuring the intensity of volume ultrasonic oscillations and Lamb waves covering a fixed distance through the test medium and on a metal plate contacting the test medium at various time points of deliberate motion of ground materials.

The authors suggest a method of determining density of ground ore particles in the pulp periodically after isolating the pulp flow in the vertical part of the measuring vessel based on measuring attenuation change values in Lamb waves covering a fixed distance on a plate contacting the medium under study and high frequency volume ultrasonic oscillations that have come through it within a certain time period.

There are given dependencies of amplitudes of measuring channels based on volume ultrasonic oscillations and surface Lamb waves, size distribution according to solid phase pulp particles for various types of ores under study, a set of curves for determining the recovered grade with regard to various types of ores under study.

The article discusses the validation process of a certain method of balancing gas contained in the pore space of rocks. The validation was based upon juxtaposition of the examination of rocks’ porosity and the effects of comminution in terms of assessing the possibility of opening the pore space. The tests were carried out for six dolomite samples taken from different areas of the ‘Polkowice-Sieroszowice’ copper mine in Poland. Prior to the grinding process, the rocks’ porosity fell in the range of 0.3-14.8%, while the volume of the open pores was included in the 0.01-0.06 cm3/g range. The grinding process was performed using an original device – the GPR analyzer. The SEM analysis revealed pores of various size and shape on the surface of the rock cores, while at the same time demonstrating lack of pores following the grinding process. The grain size distribution curves were compared with the cumulative pore volume curves of the cores before grinding. In order to confirm the argument put forward in this paper – i.e. that comminution of a rock to grains of a size comparable with the size of the rock’s pores results in the release of gas contained in the pore space – the amount of gas released as a result of the comminution process was studied. The results of gas balancing demonstrated that the pore space of the investigated dolomites was filled with gas in amounts from 3.19 cm3/kg to 45.86 cm3/kg. The obtained results of the rock material comminution to grains comparable – in terms of size – to the size of the pores of investigated rocks, along with asserting the presence of gas in the pore space of the studied dolomites, were regarded as a proof that the method of balancing gas in rocks via rock comminution is correct.

The present elaboration gives the results of investigations carried out by the VLF method in September. 1980. in Fuglebersletta, in the Hornsund Fiord area, Spitsbergen. The aim of the investigations was to localize precisely the ore-bearing veins and to trace their course.

In 2011, the Miedzi Copper Corporation (MCC) initiated its exploration program involving deep Cu-Ag deposits in the Fore-Sudetic Monocline. A very vast study area was adopted, along with the use of a wide range of research instruments. In the years 2011–2013 the exploration of MCC involved 21 concession areas. The location of concessions for exploration as well as exploration and prospecting was based on the known prognostic and hypothetical areas with confirmed contact of the Rote Fäule facies with the reduced facies, placed in the proximity of the Zechstein elevations. In 2012 and 2013, historical boreholes drilled mainly by the petroleum industry were logged, and in cases where the preservation of rock material allowed, samples were collected for chemical analyses. Moreover, a wide range of specialized examinations was performed, involving organic chemistry, coal macerals, vitrinite reflectance and petrography, with a particular emphasis on the Rock Eval method. The latter allows the presence of the so-called strong Rote Fäule associated with the presence of the richest mineralized horizons to be established. It was equally important for the purpose of exploration to perform the reprocessing of geophysical data using the innovative method of effective reflection coefficients. This allows transforming a conventional seismic image into an impulse form of seismic records, meaning a temporal sequence of coefficients, whose sections can be correlated with the logs of historical boreholes in order to trace the course of lithological series. This method provides a much higher accuracy for determining structural elements crucial for exploration than before, suggesting the presence of various tectonic phenomena important for mineralization. As a result, a more detailed mineralization distribution model was obtained and the so-called sweet spots were pinpointed, becoming an object of further drilling exploration. The number of active concessions was reduced to 6, which resulted largely not just from the absence of ore, but also from economic premises. The drilling program initiated in 2013 and still continued today allowed the discovery and preliminary documentation of three copper and silver deposits in the Fore-Sudetic Monocline. These are the Mozów and Sulmierzyce deposits, where the presence of prospective areas was previously recorded, as well as the Nowa Sól deposit, discovered in the so-called green field, where no ore exploration was previously conducted. At the current stage of identification, each of these deposits contains resources exceeding 5 million tons of equivalent copper, and the performed economic analyses indicate the viability of their extraction using the modern methods of shaft sinking, air conditioning and waste management.

The draw theory is the foundation for decreasing ore loss and dilution indices while extracting deposits from mines. Therefore, research on draw theory is of great significance to optimally guide the draw control and improve the economy efficiency of mines. The laboratory scaled physical draw experiments under inclined wall condition conducted showed that a new way was proposed to investigate the flow zone of granular materials. The flow zone was simply divided into two parts with respect to the demarcation point of the flow axis. Based on the stochastic medium draw theory, theoretical movement formulas were derived to define the gravity flow of fragmented rocks in these two parts. The ore body with 55° dip and 10 m width was taken as an example, the particle flow parameters were fitted, and the corresponding theoretical shape of the draw body was sketched based on the derived equation of draw-body shape. The comparison of experimental and theoretical shapes of the draw body confirmed that they coincided with each other; hence, the reliability of the derived equation of particle motion was validated.

The paper proposes a new electropulse apparatus for processing natural raw materials. The temperature of the crushing-and-reducing assembly of an electropulse plant is found. The results of ore crushing are presented and optimal engineering factors are offered. The elemental analysis of the test material is obtained. It is reported that the electropulse processing at the reduction stage made for significant increase in the content of non-ferrous and rare metals.

An attempt to summarize the primary iron raw materials and steel market’s hundred years history as well as influence of economic indicators on the iron ore deposit qualification for extraction has been undertaken in the paper. Steel products are crucial to the world economy, and their production has a major impact on the environment. The main factor is the huge scale of the production and growth rate, unprecedented among minerals. Iron ore and concentrates production has increased more than thirty times over the past century, and the geological resource base at the current level of consumption has provided almost 250 years of sufficiency. There have been tremendous changes in the world geography of the ore and steel industry. The iron ore mining industry is the driver of other economic activities (land transport, freight, metallurgy) and involves huge capital and human resources. The consumption of iron raw materials is also considered as an important indicator of the countries development and current or even future economic situation. Population growth remains one of the key stimulating factors. The prices of ore and iron concentrates depend on the quality of the raw material, delivery conditions, market balance and the weight of the ordered cargo. They are usually the subject of negotiations. In the past, they were long-term contracts, while short-term (yearly, quarterly) and current spot transactions are now significant. The prices of ores and concentrates in relation to steel prices are showing a strong correlation. The average iron content of the reserves has been reduced in the largest producers in the 21st century, however it does not translate into the quality of mining output. Exploitation of the richer parts of the mineral deposit is usually carried out. The high content of iron in the output is a response to the technological requirements of the metallurgy where the blast furnace charge should contain at least 56% Fe and 5–8% FeO. The current surplus of geological-mining supply (large resource base) justifies that a mineral deposit choice, destined for excavation, is economic profit maximization as well as social and environmental considerations.

The presented article describes the relationship between lithological and facies development of reservoir rocks in the area of the roof elevation of the Weissliegend sandstones, with a particular emphasis on the influence of elevation on the occurrence of low mineralization zones in the deposit area. To illustrate the variability of the deposit parameters, closely related to the facies and lithological conditions of the host rocks, three-dimensional lithological and geochemical models for two research areas were developed using the geostatistical methods and based on field observations and the sampling of the deposit. The research area includes parts of the Northern Elevation of Rudna and the surrounding depressions within the boundaries of the Sieroszowice and Rudna deposits. Based on cross-sections of the 3D models, a different deposit formation in the roof elevation area of sandstone formations has been characterized; the lithological profile is defined as „atypical” due to the absence of a copper-bearing shale series, the most characteristic layer for copper ore deposits in the Fore -Sudetic monocline. Large variations in the shape of the deposit and the irregular boundaries of both balance mineralization and enclaves of gangue have been confirmed. The presence of large-scale enclaves of igneous rock in the entire profile of the Lower Zechstein rocks (areas without the balance copper mineralization) and small areas of gangue (sandstone) enriched with anhydrite binders adjacent to the parts of balance deposit located in argillaceous sandstone has been revealed. The possibility of the occurrence of gangue, in the area of the roof elevation of the Weissliegend sandstones directly adjacent to the border with calcareous dolomite, and irregular gangue partings in sandstone formations in the balance deposit was indicated. In addition, small areas of strong enrichment in Cu sulphides were observed in the contact zones between sulphate and clay binders in the Weissliegend sandstone series.

Iron ore blending in an open-pit mine is an important means to ensure ore grade balance and resource recycling in iron mine industrial production. With the comprehensive recovery and utilisation of resource mining, the multi-source and multi-target ore blending method has become one of the focuses of the mining industry. Scientific and reasonable ore blending can effectively reduce the transportation cost of the enterprise. It can also ensure that the ore grade, washability index and iron carbonate content meet the requirements of the concentrator and significantly improve the comprehensive utilisation rate and economic benefits of the ore. An ore blending method for open-pit iron ore is proposed in this paper. The blending method is realised by establishing the ore blending model. This model aims to achieve maximum ore output and the shortest transportation distance, ore washability index, total iron grade, ferrous iron grade and iron carbonate content after the ore blending meets the requirements. This method can meet the situation of a single mine to a single concentrator and that of a single mine to multiple concentrators. According to the results of ore blending, we can know the bottleneck of current production. Through targeted optimisation management, we can tap the production potential of an open-pit mine.

Belts are widely applied in mine production for conveying ores. Understanding ore granularity, which is a crucial factor in determining the effectiveness of crushers, is vital for optimising production efficiency throughout the crushing process and ensuring the success of subsequent operations. Based on edge computing technology, an online detection method is investigated to rapidly and accurately obtain ore granularity information on high-speed conveyor belts. The detection system utilising machine vision technology is designed in this paper. The high-speed camera set above the belt is used to collect the image of the ore flow, and the collected image is input into the edge computing device. After binary, grey morphology and convex hull algorithm processing, the particle size distribution of ore is obtained by statistical analysis. Finally, a 5G router is used to output the settlement result to a cloud platform. In the GUANBAOSHAN mine of Ansteel Group, the deviation between manual screening and image particle size analysis was studied. Experimental results show that the proposed method can detect the ore granularity, ore flow width and ore flow terminal in real-time. It can provide a reference for the staff to adjust the parameters of the crushing equipment, reduce the mechanical loss and the energy consumption of the equipment, improve the efficiency of crushing operation and reduce the failure rate of the crusher.

The basis for a mineral deposit delimitation is a qualitative and quantitative assessment of deposit parameters, qualifying a deposit as an economically valuable object. A conventional approach to the mineral deposit recognition and a deposit detailed parameters qualification in the initial stages of development work in the KGHM were presented in the paper. The goals of such recognition were defined, which through a gradual detailed expansion, resulting from the information inflow, allows for the construction of a more complete decision-making model. The description of the deposit parameters proposed in the article in the context of fuzzy logic, enables a presentation of imprecise statements and data, which may be a complement to a traditional description. Selected non-adjustable and adjustable s-norm and t-norm operators were demonstrated. Operators effects were tested for selected ore quality parameters (copper content and deposit thickness) by constructing adequate membership functions. In a practical application, the use of chosen fuzzy logic operators is proposed for the assessment of the qualitative parameters of copper-silver ore in the exploitation blocks for one of the mines belonging to KGHM Polish Copper S.A. The considerations have been extended by including the possibility of using compensation operators.

The Sin Quyen deposit is characterized by a high accumulation of rare earth elements (REE). This deposit belongs to the IOCG type copper deposits (Iron Oxide Copper-Gold Deposits). In the deposit, the REE carrier minerals have been identified as follow: allanite, titanite, uraninite, monazite, apatite, chevkinite, aeschynite, bastnäsite, and epidote. In the skarn zone, contents of allanite range from single percentages to 10% in hand-size specimens. Locally, minerals of epidote subgroup which occur in large amounts in the host rocks are important. The studied allanites have concentrations of: REE (14–27 wt%), Ca (9–16 wt%), Al (8–19 wt%), Si (26–34 wt%) and Fe (12–21 wt%). Two populations of allanite are documented, the first is texturally older and probably related to the Ca-K alteration (second stage of crystallization). This population has higher REE concentration ranging from 20 to 27 wt%. The second population is texturally younger and has a lower total REE concentration ranging from 14 to 19.9 wt%, which occur mostly as a rim surrounding the older and likely arose during the K alteration with Cu-Au mineralization (third crystallization). The chemical composition indicates that the studied allanites belong to the Ce-La-ferriallanite family, with low ΣHREE and an average of 0.21 wt.%. A temperature of 355°C which was calculated using a value of δ34S isotopes is interpreted as a temperature of the second crystallization stage of allanite. In the studied deposit, excluding allanite and titanite, the other bearing REE minerals have an insignificant role in the REE balance, since they either have the total content of REE, which is often close to the WDS detection limit (rf. the epidote subgroup), or their only occur at the single points. The content of total REE in accessory uraninites is high and range from 1.311% up to 7.959% with an average value of 4.852%.

Due to the occurrence of zinc and lead ore deposits in dolomite rocks, the sphalerite concentrates obtained from these ores contain an admixture of dolomite. In practice, a substantial amount of magnesium included in zinc ores passes to the last production stage, i.e. zinc electrolysis. The magnesium present in electrolyte impairs electrical conductance and appears in the technical and economical indexes. This paper deals the attempts to remove magnesium removal from initial sphalerite concentrates by means of chemical flotation using spent electrolyte derived from zinc electrolysis. The authors attempt to substantiate the existing relationships, as well as to derermine the optimum conditions for the procedure suggested. The leaching efficiency of magnesium amounted to about 80%, and is dependent upon the stage of the leaching. Losses of zinc were below 2%, and the magnesium concentration in solution amounted to about 20%. These solution can produce magnesium and zinc, which will be presented in the following paper.