Industrial Ore Research Articles

Study on the Geological Conditions of Uranium Mineralization in Guojiaping

Guojiaping is located in the middle of China's carbonaceous-siliceous-argillite uranium mineralization belt, and its areal position, lithofacies paleogeographic environment and mineralization geological conditions can give a good reflection to its better geological background of uranium mineralization. In this paper, through analysis and comparison on previous prospecting data used in Guojiaping as well as neighboring areas, the characteristics and geological conditions of the uranium mineralization are seriously studied with theory, new technology and new methods. Guojiaping owns an upper Sinian-lower Cambrian stratum, and thus contains rich uranium source, and especially lithological combination favorable for uranium mineralization exists in upper Sinian stratum. In the study area, it is found that a group of approximately parallel NE---NNE fracture structures with equal intervals develops, and also the output of industrial uranium ores is spatially controlled by it.

The influence of phyllosilicate mineralogy on the rheology of mineral slurries

Phyllosilicate minerals have been shown to present some rheological challenges during ore beneficiation, with difficulties such as reduced flotation rates and complex tailings treatment arising. This study focuses on two phyllosilicate minerals which commonly exist as major gangue components in many industrial ores: muscovite with its thin platy structure and vermiculite which exhibits concertina-like swelling behaviour. The surface charge distribution of the minerals is evaluated using electrokinetic zeta potential measurements and potentiometric titrations. Rheology tests give the plastic viscosities and Bingham yield stresses of the suspensions. The results show that muscovite and vermiculite particles have an apparent negative charge due to the high aspect ratio of the negatively charged tetrahedral faces to the edges within a tetrahedral-octahedral-tetrahedral (T–O–T) layer configuration. The charge separation between the edges and faces results in the non-typical stacking behaviour of muscovite and vermiculite particles, forming suspensions with higher Bingham yield stresses than quartz, a non-phyllosilicate isotropic mineral with a regular non-platy morphology. However, upon yielding, these structures are destroyed and the resultant suspensions are characterised by low Bingham viscosities similar to isotropic minerals. This study provides a preliminary understanding of the flow behaviour of muscovite and vermiculite.

Untangling galvanic and passivation phenomena induced by sulfide minerals on precious metal leaching using a new packed-bed electrochemical cyanidation reactor

Because permanent galvanic contacts between gold rotating disc electrodes and slurried sulfide-rich ores are uneasy to achieve, the standard gold rotating disc electrode/slurry cyanidation arrangement has a tendency to inflate overly the importance of passivation phenomena over the corrective trend of galvanic interactions inherently present within the ore grains. A new packed-bed electrochemical reactor (PBER) was thus developed and tested to decouple and quantify the individual contributions of passivation phenomena (PP) and galvanic interactions (GI) on precious metal (gold and silver, PM) leaching rates during the cyanidation of sulfide-rich ores. The PBER was filled with homogenized mixtures of minerals (pyrite, chalcopyrite, sphalerite, chalcocite, galena, stibnite, and industrial ore), gold and silver powders, which were arranged as electrically isolated sulfide-quartz segregated bilayer(s) with permanent (inter)particle–particle electrical contacts among all constituents in each layer. Implantation of PM powders successively in the quartz layer and then in the sulfide layer, enabled PP and GI to be singled out and quantified separately for each sulfide. Galvanic interactions were found to ameliorate, to various degrees, the leaching of PM. Locating the PM powders in the quartz layer emphasized the negative impact of PP of the sulfide layer on Au and Ag dissolution, except for galena which enhanced gold leaching kinetics. Galvanic interactions due to pyrite, chalcopyrite and an industrial ore were so positive that they largely outweighed the negative impact of PM passivation. The galvanic current measured between Au/Ag electrode and each of the above minerals confirmed the positive effect of GI on gold leaching rate. In close agreement with PM recoveries, stronger galvanic currents were measured for Au-pyrite, Au-chalcopyrite and Au-industrial ore galvanic couples in comparison to those for Au-sphalerite, Au-chalcocite and Au-stibnite.

Long-term changes of heavy metal and sulphur concentrations in ecosystems of the Taymyr Peninsula (Russian Federation) North of the Norilsk Industrial Complex

The Norilsk industrial ore smelting complex (Taymyr Peninsula, Russian Federation) has significantly impacted many components of local terrestrial and aquatic environments. Whether it has had a major impact on the wider Russian Arctic remains controversial as studies are scarce. From 1986 to 2004, data on heavy metal (Cu, Ni, Zn, Hg, Cd and Hg) concentrations in fish (burbot), moss, lichens, periphyton, hydric soils and snow in and around Norilsk and the most northern parts of the Taymyr Peninsula were analysed. Very high concentrations of Cu (203 μg L⁻¹ ± 51 μg L⁻¹) and Ni (113 μg L⁻¹ ± 15 μg L⁻¹) were found in the water of the Schuchya River close to Norilsk. Heavy metal concentrations in burbot liver were highest in Lake Pyasino near Norilsk compared to other study regions that were >100 km distant. From 1989-1996, Cu (121 μg L⁻¹ ± 39 μg L⁻¹ SD), Zn (150 μg L⁻¹) ± 70 μg L⁻¹) and Ni (149 μg L⁻¹ ± 72 μg L⁻¹) snow concentrations were greatest in Norilsk, but were low elsewhere. By 2004, these concentrations had dropped significantly, especially for Cu-74 μg L⁻¹ (±18.7 μg L⁻¹ SD), Zn-81.7 μg L⁻¹ (± 31.3 μg L⁻¹ SD) and Ni-80 μg L⁻¹(±18.0 μg L⁻¹ SD). Norilsk and its surroundings are subject to heavy pollution from the Norilsk metallurgical industry but these are absent from the greater Arctic region due to the prevailing winds and the Byrranga Mountains. Pollution abatement measures have been made so further investigations are necessary in order to assess their efficiency.

Geomaterials on the Basis of Analcime-Bearing Rocks

Analcime-bearing rocks (Komi Republic, Russia) are perspective raw for geological materials. The article represents possibilities of their application for water purification, as raw for ceramic industry and poor ore for aluminum industry.

New potentially industrial sulfide indium-manganese ore type

The Vysokogornoe ore field is located within the Southern Verkhoyan synclinorium, which is a part of the Okhotsk volcanic belt. Metallogenically it is related to the Yudom segment of the Southern Verkhoyan Province specializing in silver–tin–poly� metallic ore. There is a united system of ore veins in aleuropsammite of the Verkhoyan terrigenous unit pararagenetically related to Cretaceous granite within the considered field. These veins are controlled by the zone of a regional fault of submeridional strike feath�

Electrochemical behavior of gold cyanidation in the presence of a sulfide-rich industrial ore versus its major constitutive sulfide minerals

Abstract A detailed study on the relative importance of passivation phenomena and galvanic interactions during gold cyanidation was carried out. Mineral disc electrodes consisting of a sulfide-rich industrial ore and major sulfide components were prepared along with an Au electrode (gold/silver alloy) in use for gold leaching rate tests. These leaching tests that were conducted by hyphenating gold and mineral disc electrodes conjointly in one electrochemical cell or in two separate electrochemical cells objectified both passivation-induced setbacks as well as boosts by Au/mineral galvanic interactions on gold dissolution. To decipher the role of sulfide ores on gold cyanidation, a systematic study was performed by monitoring the leaching behavior of an Au disc electrode successively immersed in slurries of industrial ore and its major sulfide constituents, i.e., pyrite, sphalerite and chalcopyrite. The tested mineral constituents and ore exhibited an inhibiting effect on gold leaching, decreasing in the following order: chalcopyrite > sphalerite > industrial ore > pyrite. Pre-oxidation of the industrial sulfide ore prior to cyanidation improved the gold leaching rate. However, in spite of noticeable reductions in cyanide consumption, no beneficial effect of pre-oxidation on gold leaching was observed for the major sulfide (ore) constituents when tested separately. Although cooperating permanent galvanic interactions between gold and main constitutive minerals in the industrial ore prompted higher gold leaching rates, predictability of the latter from lab-controlled leach tests of the nearly pure constitutive sulfide minerals still remain premature.

Multivariate statistical analysis of gold cyanidation plant data

Dynamic measurements performed around an industrial gold ore leaching plant with two leaching tanks were used to perform a multivariate statistical analysis to extraction information from this data set. Performance indices related to leaching rate constants were generated in the data set pre-processing. Then, Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to find correlations between the process variables. It is shown that in the studied case, the behaviour of the two cyanidation tanks can be modelled separately. Despite correlated inputs, noisy measurements, and a few missing variables, it was possible, through multivariate regression based on the Projection to Latent Structures (PLS) technique, to propose an empirical model of the first leaching tank.

Peculiarities of the structure and conditions of formation of the Chin Shan porphyry-copper-gold deposit (People’s Republic of China)

The Chin Shan porphyry copper-gold deposit is located in the south of China in Fujian province. This is a large deposit containing more than 1000 t industrial reserves of gold and more than 0.5 mln. t of copper. It is related to a very complex polygenic and polychronic type of porphyritic plutonogenic hydrothermal deposits formed during the final stage of the formation of volcano-plutonic granite dioritic complex of the Cretaceous age. Later post-magmatic fluids of the Late Mesozoic (Kimmeridgian) epoch of tectonic magmatic activation also took part in ore formation. The gold-silver and polymetallic activation is related to precisely this epoch. The modern shape of the deposit and all industrial ores appeared in the Quaternary period during the formation of the unique extended oxidation zone.

A simulation model of the comminution–liberation of recycling streams: Relationships between product design and the liberation of materials during recycling

End-of-Life (EOL) products can be considered to be industrial ores, since the minerals (materials can be considered as minerals) contained are recovered, processed and reintroduced in the material production systems as industrial ores. Therefore, the principles used in classical minerals processing can be applied to describe the comminution and liberation of EOL products during recycling. Similarly as for natural ores, particle size reduction and liberation have an important role in the quality of the recycling streams and on the possibilities for their further processing and reintroduction in the resource cycles. A simulation model is presented that describes the relationships between product design and the liberation level attained by shredding. The model simulates the comminution and liberation phenomena as a function of the product design variables. From the analysis of experimental samples, sensitivity analysis and simulations, relationships are illustrated and discussed. The breakage behaviour of End-of-Life (EOL) products differs largely from these natural minerals. Therefore, although many definitions can be adapted from classical minerals processing, a different approach is required in the modelling of the comminution–liberation of EOL products. This is the first step in the development of these type of models, and much experimental work is required for further development. The simulation results using a passenger vehicle as example show that during product design, the materials and joints among them can be chosen to obtain the best possible liberation and the lowest possible contamination. Therefore, industrial ores can be ‘designed’ for recycling, to reduce recycling losses and optimise resource efficiency. The aim is to implement this knowledge in the product design stage of defining materials and connections.

Treatment Of Biologically Treated Distillery Effluent - A Case Study

The paper addresses physico-chemical treatment of biologically treated distillery effluent using conventional and non-conventional coagulants. Conventional coagulants, viz. ferrous sulphate, ferric sulphate, and alum were used during the study. Ferrous sulphate in combination with lime was found to be optimal which could remove 78.50 percent COD with efficient removal of colour. Further, commercially available polyelectrolyte aid, Percol 47 was found to be suitable for the reduction of ferrous sulphate requirement from 20 gL −1 to 10 gL −1 , which produced the same quality of effluent without affecting the overall efficiency of the treatment. Non-conventional coagulants viz. wastewater from an iron pickling industry and titanium ore processing industry were also evaluated. The iron pickling wastewater also removed 86.8 percent and 92.5 percent residual COD and BOD, respectively, from the biologically treated distillery effluent. Further, commercial activated carbon was assessed for polishing the effluent after treatment with coagulants. A dose of 8 gL −1 of carbon with contact time of 45 minutes was found to be optimal. The effluent generated after treatment with activated carbon had COD concentrations less than the discharge standard for inland surface water as prescribed by Central Pollution Control Board (CPCB), Ministry of Environment and Forests (MOEF), Government of India.

A portable load cell for in-situ ore impact breakage testing

This paper discusses the design and characterisation of a short, and hence portable impact load cell for in-situ quantification of ore breakage properties under impact loading conditions. Much literature has been published in the past two decades about impact load cells for ore breakage testing. It has been conclusively shown that such machines yield significant quantitative energy-fragmentation information about industrial ores. However, documented load cells are all laboratory systems that are not adapted for in-situ testing due to their dimensions and operating requirements. The authors report on a new portable impact load cell designed specifically for in-situ testing. The load cell is 1.5 m in height and weighs 30 kg. Its physical and operating characteristics are detailed in the paper. This includes physical dimensions, calibration and signal deconvolution. Emphasis is placed on the deconvolution issue, which is significant for such a short load cell. Finally, it is conclusively shown that the short load cell is quantitatively as accurate as its larger laboratory analogues.

Separation of spectral and non-spectral interferences by on-line high performance ion chromatography inductively coupled plasma sector field mass spectrometry (HPIC-ICP-SFMS) for accurate determination of 234U , 235U, 238U and 232Th in industrial ores

A novel and versatile method for the determination of 232Th, 234U, 235U and 238U in milling grade ores and intermediates containing high amounts of rare earth elements (REE) was developed. Spectral and non-spectral interferences were eliminated by on-line matrix separation with high performance ion chromatography (HPIC) using 2,6-pyridinedicarboxylic acid (PDCA) as complexing agent. Hyphenation to inductively coupled plasma sector field mass spectrometry (ICP-SFMS) introduced a highly sensitive method of detection. Quantification of uranium and thorium could be established using external calibration and post-column internal standardization. Elemental levels down to concentrations of pg g−1 to ng g−1 in samples containing rare earth elements as the main matrix components could be assessed. The method was validated for 235U and 238U by comparison of isotope dilution mass spectrometry (IDMS) results without and with on-line matrix separation using a matrix matching pure cerite carbonate sample containing about 0.5 ng g−1235U and 65 ng g−1238U. The results of the external calibration were in good agreement with the IDMS results and overlapped within their uncertainties. 232Th was quantified to about 30 ng g−1 (solid material) by on-line HPIC-ICP-SFMS using 233U as internal standard. The results were in excellent agreement with those obtained by HPIC-ICP-SFMS using indium as internal standard. Measurement of a series of industrial samples proved the versatility of the method and can give a quick assessment of whether a material is suitable for a further production process or not, since isotope dependent limit values have to be determined.

Pb isotopes in sediments of Lake Constance, Central Europe constrain the heavy metal pathways and the pollution history of the catchment, the lake and the regional atmosphere

Pb isotope ratios and Pb concentrations of well-dated sediments of Lake Constance, Central Europe have been analyzed using thermal ion mass spectrometry. Sequential extraction studies indicated isotope homogeneity of the leachable Pb components within the investigated layers. Since the middle of the 19th century a significant anthropogenic Pb component appeared in the lake sediments, and rapidly approached concentration levels similar to that of the geogenic Pb background (20 ppm) at the beginning of the 20th century. Anthropogenic Pb was predominantly transferred to the lake sediments via the atmosphere. Pb sources were coal combustion, industrial ore processing and leaded gasoline. The flux of a fluvial Pb component to the lake sediments, additive to atmospheric Pb deposition, peaked in about 1960. This flux is attributed to (re)mobilization of Pb from polluted parts of the lake catchment, and indicates the change of catchment soils from a pollution sink to a heavy metal source. The strong reduction of anthropogenic Pb in the uppermost lake sediments since the 1960’s has been caused by advances of environmental protection. The lake sediments record the changing fluxes and the isotope composition of the deposited aeolian Pb pollution. During the 20th century aeolian Pb fluxes to the lake sediments were in the range of 1–4 μg/cm 2/a. During peak emission periods of gasoline Pb to the atmosphere (1960–1990) the aerosol Pb isotope composition was rather constant ( 206Pb/ 207Pb: 1.12–1.13) and probably a mixture of Canadian and Australian with Russian and Central European Pb types. Aeolian Pb isotope and Pb flux trends in the lake sediments as a whole agree well with the trends found in Alpine glaciers (Döring et al., 1997a,b) and in ombrotrophic peat bogs of Switzerland (Shotyk et al., 1996). However, different industrial Pb components were deposited in the archives of aeolian pollution during the early 20th century.

An experimental study with a vortex magnetic separation (VMS) device

A vortex magnetic separation (VMS) system was designed and applied to the separation of a number of materials. An important feature is that the slurry passageways and the vortex magnetic capture regions are separately arranged in the device. The vortex traps are formed in the vortex magnetic capture regions under certain conditions so that magnetic particles can be driven into the vortex traps from the slurry and captured there. The VMS was used to treat an artificial mixture of wolframite and quartz and some real industrial ores. This paper presents some experimental results obtained. The results showed that the VMS can largely solve the mechanical entrapment problem encountered by the current practice of HGMS. VMS can be run at higher slurry velocities and so produce a higher output. The preliminary experiments carried out on industrial ores showed that this device can treat samples with a wide size range without blockage.

Development of a new jet mill for very fine mineral grinding

In order to achieve maximum micronization with a minimum of power consumption, a highly efficient prototype micronizer has been designed. The apparatus is based on the principle of countercurrent jet milling in closed circuit with a pneumatic classifier capable, among other things, of controlling the top size of the final product. Systematic experimental investigations allowed to analyse the dynamics of breakage due to impact and attrition and to optimize the fluid dynamics circuit, the design and the resulting prototypes, the adjustable operating parameters, the size class characteristics of the feed and the performance achievable. The results obtained for a variety of industrial ores (talc, kaolin, baryte) are presented, with particular reference to the micronization of a high grade baryte concentrate with an elevated degree of whiteness.

Digital multispectral techniques and automated image analysis procedures for industrial ore modelling

The choice of suitable beneficiation strategies is strictly linked to the precise mineral-petrographic, textural and structural characterisation of the ore. Careful analysis and precise modelling of spatial relationships between different mineralogical phases constituting the ore is the basis of any procedure which aims at forecasting the separation results. The textural and structural characterisation of the ore on a macro/microscopic scale is carried out through optical microscopy and in some special cases by SEM analysis. The main purpose of these procedures is that of obtaining information which can be used in numeric form as data for the models. The traditional procedure consists of analysing sections under the microscope to obtain distribution maps for the different mineral phases and making a synthesis of these data so that they can be easily managed inside a numeric procedure. In the last few years the development of procedures based on techniques of optical image processing has greatly reduced the analysis time, allowing a better characterisation of the ore in textural and structural terms. The growing development of research in electronics and computer science and the subsequent availability of hardware and software products, allow handling and processing of full colour digital images, at lower and lower costs. In this paper the problems arising from the adoption of such a digital approach both in terms of quality of results (mineralogical species automatic identification) and in terms of further processing of the data (morphological and morphometrical characteristics and assessment of the mineral species constituting the ore), are described and discussed.

Investigation of particle breakage mechanisms in a batch ball mill using back-calculation

Simultaneous estimation of breakage rate and distribution function parameters has been carried out for two industrial ore samples and three types of cement clinker using dry batch ball mill data. Unique parameter estimates were obtained through a back-calculation approach using non-linear least squares fitting. The batch mill operating conditions were chosen to resemble industrial grinding situations. Investigation showed that breakage distribution and rate parameters did not conform to the commonly used functional forms. The analysis demonstrates that the breakage distribution function correlates to material property and particle size, and the breakage rate function also changes with material type and with mill content size distribution. The mechanisms of particle breakage in a ball mill inferred from the fitted breakage rate and distribution functions are also discussed in this paper.

The Multiple Factors and Multiple Stages Involved in Sedimentary Ore Genesis

Sedimentary mineral deposits cannot be formed by any kind of simple chemical reactions, but are products of a complex multi-episodic process depending on multiple factors. The whole process is governed by a combination of sedimentary, geochemical, biogeochemical, organic geochemical, paleoclimatical. mechanical agents as well as by the properties of relevant earth crust segment and its structural making up and tectonic mobility. A sedimentary ore deposit is nothing but a special kind of sedimentary facies, characterized by definite sedimentary assemblages. Different genetic types of ore deposit and different ore associations characterize different sedimentary assemblages in different ore-forming belts. Crustal movement, including orogenic, epeirogenic and, particularly eustatic events, controls the formation and distribution of all kinds of sedimentary mineral deposits, most of which occur within the transgression front in the lower part of marine transpressive series. Mineral deposits of economic importance cannot be precipitated directly from sea water, but are products of terrestrial imbibition, biological enrichment and pore water concentration instead. Deposits formed above the wave base in the inner continental shelf under strong dynamic condition of sea water are often large and predominantly clastic in texture with commercial grade. Below the wave base in the outer continental shelf environment, where it is more or less dynamically stagnant and oxygen-deficient, the resulted industrial ore deposits are mostly of diagenetic or strata-bound type, formed through deep-burying diagenesis. The theory of multi-factor and multi-episodic metallogenesis includes three major aspects: the ore-forming process, the sedimentary environment and the geological background. The study of the formation process itself and the sources of ore-forming elements would provide useful clues to further prospecting. Whereas, investigations of the sedimentary environments should shed light on the spacial distribution of deposits and the analysis of geological background would contribute a lot to our knowledge of the temporal evolution of sedimentary metallogenesis.

Applications of static electricity in coal and ore beneficiation: The contribution of the University of Cagliari to the development of new separators and to the improvement of the processing technology

Electrophysical properties of natural minerals can be exploited for separation purposes in high intensity static fields in order to obtain commercial products starting from crude ores. For the development of industrial processes high selectivity of charging is needed; this can be achieved on condition that electrophysical properties of mineral species to be separated are well differentiated. On the basis of the indication of the fundamental research, interesting possibilities have been experimented regarding treatment of mineral mixtures using original apparata designed and built both on the laboratory and pilot plant scales. Some beneficiation problems to the solution of which electrostatic separation can give substantial contribution, are discussed in the paper. Coals can be processed with electric methods with the aim of obtaining low ash, pyrite-free cleaned products. Actually there is a strong interest in the set-up of suitable dry methods for the preparation of coal-water slurries capable of replacing fuel oil in heath and power generation. The upgrading of lean phosphates is a very important challenge; in arid areas the ore can be beneficiated only with dry processes, among which electrostatic methods appear as the more promising. These can can be successfully applied for the separation of potassium salts, the recovery of heavy minerals contained in marine placers and the treatment of complex industrial ores. Finally, the prospects of electric separation are pointed out and discussed.