黒鉱選鉱操業の概況と問題点

Nickel sulphide ore subjected to this investigation was taken from the Marmara district of Turkey, where widespread chromite mineralization can be observed. Some amounts of magnetite and chromite exist in the ore together with sulphide and oxide type nickel minerals. The ore sample contains 1.32% Ni, 10.79% SiO2, 78.39% Fe2O3, 1.3 g/t Ag, and 1.0 g/t Au. The ore sample is constituted of about 70% magnetite, 15% sulphide minerals, and 5% chromite and iron oxides, as well as 10% gangue minerals. Nickel mineralization in the ore such as pentlandite, violarite, millerite awaruite, and asbolanewas determined. Due to the complex structure of mineralization, a combination of gravity-separation and flotation methods was applied for the concentration of nickel sulphide and oxide ores. A nickel concentrate containing 12.32% Ni was produced with 89.7% recovery and final tailings with 0.088% Ni can be disposed with 4.9% of metal loss. A process flowsheet was developed according to the optimum test results. The importance of this research is that it is the first example of developing a flowsheet for the beneficiation of sulphide and oxide type nickel mineralization observed together in chromite ore deposits.

The use of simple analytical techniques to assess surface oxidation of sulphide ores

Tailings generated during ore processing may host significant residual contents of valuable commodities, including critical metals. The particle properties of the tailings, such as mineralogy, particle size, and the surface liberation of ore minerals, strongly control processing behaviour. This study explores a novel combination of methods for incorporating particle data, derived from automated mineralogy, into geometallurgical models of tailings deposits to better understand their reprocessing potential and the economic feasibility of re-mining. This was achieved through binning of different particle types, geostatistical modelling of particle bin frequencies, and bootstrap resampling to reconstruct particle populations. The spatial distributions of processing-relevant particle properties throughout the tailings deposit were predicted with corresponding uncertainties. There are clear systematic trends in the spatial distributions of different particle types, resulting from the sedimentary-style deposition of the tailings. For instance, the tailings nearer the dam walls comprise coarser, silicate-rich particles, while fine-grained and well-liberated sulphide mineral particles are more abundant in the centre of the tailings deposit. As a result, robust models could be developed for the spatial distributions of particle size and mineralogy, which strongly control the sorting of particles during deposition, and other related properties, such as sulphide mineral grain sizes. Finally, a bulk sulphide flotation process was simulated and acid mine drainage potential estimated using the interpolated particle data. Around 58% of the sulphide minerals present could be recoverable by flotation, with the recoverable sulphide portion decreasing towards the centre of the TSF due to the fine-grained nature of the sulphide minerals. The acid mine drainage potential of the tailings is estimated to be moderate to high, indicating that the carbonate minerals present are not sufficient to neutralise the high acid-generating potential of the sulphide minerals. Overall, this study demonstrates how particle-based geometallurgical models can be developed and utilised for practical applications, with the aim of improving the accuracy of resource and reserve estimations of tailings deposits and the sustainable and responsible management of anthropogenic resources. The methodology proposed here can be easily transferred to other tailings deposits.

Sulfur cycle in the Valles Caldera volcanic complex, New Mexico – Letter 1: Sulfate sources in aqueous system, and implications for S isotope record in Gale Crater on Mars

The paper presents chemical and mineralogical characteristics of calamine ore from the Pomorzany mine. A flowsheet for recovery of sulphide minerals of zinc and lead in the form of the Zn-Pb bulk concentrate was presented. In the following part, preparation of the feed for flotation of Zn-Pb oxide minerals and optimal conditions for separation from it iron sulphide minerals, represented by marcasite, were determined. In the final section the results of flotation of Zn-Pb oxide minerals with anionic collector AM2 belonging to the hydroxyamide group of collectors and a cationic collector in the form of a coconut amine, being a mixture of primary aliphatic amines, were presented. Basing on the obtained results, a technological flowsheet for the recovery of Zn-Pb sulphide and oxide minerals from the calamine ore of the Pomorzany mine was presented.

Cho-Dien zinc oxide ore is characterized by strong weathering. The ore has a content of 6-10% zinc content. Zinc occurs mainly in hemimorphite (calamine), smithsonite and chalcophanite. The rocks are mainly goethite, clay and quartz. However, no feasibility study has been conducted to treat this ore in practical production. This paper presents the effects of different types of flotation reagents (collectors, depressants, dispersers, etc.) on the beneficiation process of zinc oxide ore. From there, the suitable flotation reagents dosages and regimes were given. The research result shows the concentrate has a content of 20-25 % Zn at a recovery ratio of 55-60%. These preliminary results suggest that developing a technically and economically feasible beneficiation technology for Cho-Dien zinc oxide ore is possible.

Summary Water consumption related to the life cycle of metals is seldom reported, even though mines are often situated in very dry regions. In this study we quantified the life cycle consumption of groundwater and fresh surface water (blue water footprint [WF blue ]) for the extraction and production of high‐grade copper refined from both a copper sulfide ore and a copper oxide ore in the Atacama Desert of northern Chile. Where possible, we used company‐specific data. The processes for extracting copper from the two types of ore are quite different from each other, and the WF blue of the sulfide ore refining process is 2.4 times higher than that of the oxide ore refining process (i.e., 96 cubic meters per metric ton [tonne] of copper versus 40 cubic meters per tonne of copper). Most of the water consumption (59% of WF blue ) in the sulfide ore process occurred at the concentrator plant, via seepage, accumulation, and also by evaporation. In the oxide ore process, the main user of water is the heap‐leaching process, with 45% of WF blue . The crushing and agglomeration operations, electrowinning cells, and solution pools are also significant contributors to the total consumption of water in the oxide ore process. Most of the water consumed in the oxide ore process was lost to evaporation. The WF blue of the oxide ore process can be reduced by preventing water evaporation and using more sophisticated devices during irrigation of the leaching heaps. The WF blue of the sulfide ore refining process can be reduced by improving water recovery (i.e., reducing seepage, accumulation, and evaporation) from the tailings dam at the concentrator plant. Using seawater in the production of copper is also a promising option to reduce the WF blue by up to 62%.

The properties of complex ores that determine the technologies for their processing are inherent in the minerals and their compositions, rather than individual chemical elements. Therefore, conventional production control based solely on the chemical composition cannot fully determine the quality and technological properties of ores and enrichment products. In recent years, the use of automated X-ray diffraction quantitative phase analysis (XRD QPA) using the full-profile Rietveld method [1] has been intensively developed in global practice for controlling the mineral composition. The essence of the method is to model the diffraction pattern of the sample measured on a diffractometer with calculated diffraction patterns of its phases, which are computed from the atomic-crystalline structures of minerals. This refines the lattice parameters, peak profile of the diffraction peaks of phases, textures, and possibly the crystal structure parameters of the main phases of the sample. This makes Rietveld QPA the most accurate of the existing methods. However, the Rietveld QPA method is effective only when the qualitative mineral composition of ores and products is known and stable, and even partial changes in samples lead to errors. This impedes the development of automation of Rietveld XRD QPA in cases of significantly variable mineral composition.

Ball mills are used for the second stage of ore grinding in mining operations by proportioning ore piles. Controlling the operating conditions of ball mills is one of the key factors for optimal mill perform and high mill load turnover. One of the factors affecting the efficiency of the ball mill is the loading of the balls. Optimum distribution of ores according to the size of the mill, increasing the efficiency of the grinding process and reducing energy consumption are achieved. In addition, the ore properties are one of the important parameters for the optimal utilizing of the ball mill. Ore can have various properties, such as hardness, density, moisture content, etc., which can affect the ore’s productivity and grinding efficiency

The Hongge giant Fe-Ti-V oxide ore deposit is hosted by a layered intrusion located in the central part of the Emeishan large igneous province, SW China. The intrusion is relatively small in comparison with other typical oxide-bearing intrusions worldwide; it consists of a lower olivine clinopyroxenite zone, a middle clinopyroxenite zone, and an upper gabbro zone (herein referred to as the lower, middle, and upper zones). Most of the economic Fe-Ti-V oxide ore layers occur within the middle zone. The Hongge oxide ores are depleted in REE and enriched in Zr, Hf, Nb, and Ta as compared to the associated clinopyroxenites. This enrichment of elements that are compatible in titanomagnetite is consistent with the interpretation that the ores formed by accumulation of magnetite and ilmenite. As in the nearby coeval Panzhihua Fe-Ti-V oxide deposit described previously by others, mafic silicates in the Hongge deposit have much higher MgO contents than those in other oxide deposits associated with large layered intrusions in the world. This highlights the importance of relatively primitive parental magma becoming saturated in titanomagnetite at an early stage in the genesis of the giant Fe-Ti-V oxide deposits in the Emeishan large igneous province. Phase equilibrium constraints suggest that the parental magma of the Hongge deposit is similar to that of some of the most primitive high Ti basalts in the Emeishan large igneous province. The ferrobasaltic parental magma and the ferropicritic primary magma of the Hongge intrusion are similar in major and trace element composition to the ferropicritic-ferrobasaltic magma in the Pechenga belt, Kola peninsula, Russia. Depletion of incompatible trace elements in the oxide ores and associated rocks in the Hongge intrusion as compared to the coeval high-Ti basalts suggest that not all the magma involved in the development of the Hongge intrusion has been retained in the intrusion. The occurrence of multiple Fe-Ti oxide layers alternating with Fe-Ti oxide-bearing silicate layers within a single zone and the repetitive appearance of sulfides, olivine, and Cr-rich layers suggest that multiple pulses of magma were involved in the formation of the Hongge intrusion and related Fe-Ti-V oxide deposit. We propose that the middle zone of the Hongge intrusion was a magma stepwise flow-through system and that some of the liquid was lost to the peripheral lavas to form the basalt.

12 - Mill Tailings

This study investigated the geological properties of the uranium ore found in Pa Lua - Pa Rong area for potential industrial exploitation. A combination of field measurements, modeling and several mathematical approaches were employed to characterize the geological properties of the uranium ore. We found: i) The thickness of the ore bodies ranges from thin to medium, exhibiting varying degrees of instability (Vm = 83.8÷102.8%). The average U3O8 content indicates that the ore bodies belong to the poor ore type, with an unevenly distribution (Vc = 57.9÷100.9%); ii) The morphology and structure of the ore bodies are highly complex, exhibiting irregular variations. The thickness of the ore bodies shows a positive correlation with the uranium content in each body (R = 0.6-0.7); iii) The variograms of the U3O8 concentration and the thickness in various directions exhibit a spherical pattern, indicating an autogenous effect. The most significant variation in uranium content aligns with the dip direction (50°±12.5°), while the least variation aligns with the strike of the ore body (140°±12.5°). The variations in ore body thickness are more straightforward and consistent with those of the uranium content. In summary, these findings provide valuable insights into the characteristics of uranium ore in Pa Lua – Pa Rong area. The results contribute to a better understanding of the geological processes and can inform some effective exploration strategies for uranium resources in this region.

Assessing and reducing risks at the Montague and Goldenville gold districts in Nova Scotia

The leaching kinetics of an oxide gold ore with iodide/iodine solutions

A comminution process is a material size reduction and separation process which is primarily used in the aggregates and the minerals processing industry. Knowledge related to equipment’s operation, raw material properties, operational strategies, control system, maintenance, etc. is needed to design a capable plant. New needs are arising from the industry for existing operational crushing plants such as investigation for improvements, upscaling, and downscaling of the capacity. The paper presents an application of simulation-driven development for a crushing plant in an existing gold processing plant. Due to the change in ore characteristics and the need for optimizing the cost of operation, it is required to investigate the opportunities for improvement and alternative options for downscaling the capacity of the plant. A systematic process for configuring, developing, and evaluating alternative concepts using a process simulation tool is presented. The results show the process of generating knowledge for alternative crushing plant operation settings and how the choices can be selected and eliminated using boundary conditions. The evaluation presents possible improvements and alternative concepts with their opportunities and pitfalls.