Lead Ore Research Articles

Sampling and combined Pb and Ag isotopic analysis of ancient silver coins and ores

The combination of Pb and Ag isotopes in silver coins, artefacts, and ores greatly helps identifying ancient metal sources and detecting alteration such as lead addition, ore mixing, and metal recycling. The present study proposes a new set of procedures suitable for high-precision analysis of lead and silver isotopes in Ag-bearing ores and ancient silver coins. The protocols for combined Pb and Ag extraction and purification are based on multi-step ion-exchange and reversed-phase partition chromatography. In addition to conventional drilling, which irreversibly damages the silver object being sampled, a new method was developed to collect metal from silver coins by etching their edges with a solution of hydrogen peroxide and ammonia (H2O2 + NH4OH), either pure or with added dispersed silicon carbide (SiC) to increase etching efficiency, a technique that only damages the coin patina. This technique can also be applied to silver artefacts other than coins with minor modifications to adapt to different object shapes. Multi-collection inductively-coupled plasma mass spectrometry (MC-ICP-MS) was used to measure the isotopic compositions of both Pb and Ag in ores and coins. Variations in Pb and Ag isotopic compositions are uncorrelated for all the material analyzed, whether ores or silver coins, which demonstrate that isotope variability results from physically different processes. Evidence of mixing between different components is observed for ores, while etched and drilled coins show a conspicuous range of Pb and Ag isotopic compositions. The latter is interpreted as resulting from mass-dependent fractionation during surficial alteration under oxidizing burial conditions, and from patina formation. Silver in patina is isotopically light due to the formation of Ag2S, while the layer below the patina is isotopically heavy. Preliminary patina removal followed by H2O2 + NH4OH etching with suspended SiC may be used as an alternative to coin drilling when the latter is not possible such as for rare and precious coins. The present techniques will further help distinguish primary Pb isotopic variability in artefacts and coins from secondary variations due to underground interaction with the water table, weathering from prolonged burial, and curatorial handling.

Mining and metallurgical activity in the medieval Serbia

The mining and metallurgical activity has a centuries-old tradition in Serbia. Copper, iron and gold are the basic metals in the ore of Eastern Serbia. Lead, zinc, iron and silver ore are present in central Serbia, while antimony and lead ore are predominant at the location of western Serbia. The strength of Nemanjic's Serbia was mostly based on the development of this activity. With the arrival of the Turks, the mining and metallurgical activity weakened, and at the beginning of the 18th century it completely become extincted. Almost all current mines of polymetallic ores in Serbia appeared on the locations of medieval mines.

An efficient and environmentally friendly route for PbS crystal recovery from lead ash generated in tin removal section (LATR) via high-speed leaching and recrystallization method

This paper mainly investigated the synthesis of a high purity PbS crystal directly from lead ash which was collected from Tin ash removal process (LATR). The LATR was firstly disposed by nitric acid leaching system to generate the lead nitrate solution. The PbS crystal was prepared by mixing the lead nitrate solution with the sodium sulfide at the room temperature (25?C). The effects of molar ratio of HNO3 to Pbin the LATR on Pb leaching efficiency was investigated, demonstrating that the Pb leaching efficiency could attain to 82.9 % at molar ratio of 3. The leaching ratio of As, Cu, Fe, and Al generally increased with increasing molar ratio of HNO3 to Pbin the LATR, while 99.99 wt% of Sn was still left in the residue. In the process of generating PbS crystal from the leaching solution, the yield of PbS crystal increased with increasing molar ratio of Na2S to Pbin the filtrate. The yield of PbS crystal could up to 93.1% at a molar ratio of 1.5. Overall, this method proved to be an efficient and environmental friendly route for synthesis of high quality PbS crystal directly from the common lead containing waste from the lead ore or secondary smelting factory.

Selection of the optimal contour of the open pit in mining the lead and zinc ore deposit with the increased mercury content

Mining processes are complex and complicated, with many different economic, technical, environmental and other parameters that must be planned before the project gets its practical value. Many of these parameters are evaluated independently of others, due to the expediency and difficulties in predictting values for variables under consideration. Costs, prices, reserves, mining and processing of ore, as well as many social aspects, such as issuing permits for works, are absolutely crucial for the project evaluation. Each ore body is different, but the main steps in the open pit planning, when the main goal is to maximize NPV, follow the same principle. These steps are presented as the linear for simplicity. The actual planning process is an iterative process, in which some steps or a combination of steps are repeated many times with the sensitivity analysis.

Pedeset godina metalurške proizvodnje cinka i kadmijuma u Srbiji

Serbia has plenty of rich sites and active excavation mines of polymetallic ores of lead and zinc and centuries-old practice of their exploitation. In Serbia, the metallurgical processing of zinc concentrate started in 1955 at Zorka company in Šabac, while in the town of Kosovska Mitrovica, it began in 1967 at the Trepča combine. Several factors, including the fall o Yugoslaviam general societal circumstances and ownership transition, lead to a significant decline in production since 1992. It developed to the final halt of zinc's metallurgical production in 1999 at Trepča and in 2002 at Zorka. During the work-life o both production sites, since they opened till they closed, there were several reconstructions and capacity expansions, and all the while, the normalization and renewal of zinc production in Serbia hasn't been realized till 2021.

Risk Assessment of Natural Radionuclide Contamination in Lead–Zinc Sulfide Ores Mining

Lead and zinc ores are the most important natural raw materials widely used in the industry. These types of ores contain different amounts of radionuclides that expose workers to radiation during extraction, transport, and processing. In this study, 22 samples were collected, including 18 samples of lead–zinc ore and 4 samples of mining waste. Specific activities of 226Ra, 232Th, and 40K were determined using a high-purity germanium gamma radiation detector (HPGe). The specific activities of corresponding radionuclides in lead–zinc ore samples varied in the range (< 0.21–107.61), (1.91–48.13), and (< 10.16–664.04) in Bq/kg, respectively. According to the European Commission’s dose assessment instruction for workers, the effective dose absorption was calculated for different scenarios, as transport, outdoor storage, and internal storage, which varied from 0.76 to 10.23 µSv/y, 1.05–17.00 µSv/y, and 1.20–19.20 µSv/y, respectively. For all lead–zinc ore samples, effective doses in various scenarios were lower than the intervention level (1.0 × 103 μSv/y) determined by the International Commission on Radiological Protection.

Comparative analysis of internal and external characteristics of lead-acid battery and lithium-ion battery systems based on composite flow analysis

Due to human's diversified requirements and the constraints of external environmental factors, lead-acid batteries and lithium-ion batteries coexist and compete with each other now. However, the difference of internal and external characteristics between the two battery systems is unknown. Based on the analysis of the internal flows and its impact on the external environment, this research established a framework for the relationship between the battery system and the external systems. The internal and external evaluation index system was developed. The external influence results of the two systems in China mainland at 2016 show that when the amount of social service provided by lead-acid battery system (LABS) was 1.6 times more than that of lithium-ion battery system (LIBS), the consumed lead ore was 52 times more than the lithium ore; the total energy consumption of the systems was 23.12 million tce, and that of the LABS accounted for about 63%; waste lead emissions was 2.7 million tons, and the waste lithium emissions was 40,900 tons lithium carbonate equivalent (LCE); the total economic outcomes were 220.23 billion yuan, and the proportion of that in LABS was about 44.4%. The recycle rates of LABS and LIBS were 0.368 and 0, respectively; the energy density of the LIB was 4.4 times of that in LAB; the “price” of the lithium in lithium ore and LIB were about 12 times and 3 times of that in LAB. The management suggestions on sustainable development were put forward from the aspects of waste recycling, product structure in the application field and product performance. What's more, future plan was discussed for the sustainable development.

Sustainable materials from hazardous lead ore flotation waste in composites with spent foundry sand and clay

The aim of this study was the experimental tests of the mechanical properties and structure formation processes of sustainable ceramics from hazardous lead ore flotation waste, spent foundry sand, and natural red clay to produce sustainable ceramics. The lead was mined on a large scale from lead ores in the city of Adrianopolis, Brazil, for 58 years. The wastes from this activity bequeathed profound environmental and social impacts. The mechanical characteristics of twenty compositions of the ceramics were analyzed through the flexural resistance, water absorption, apparent density, and linear shrinkage; the study of the physicochemical processes of the ceramics’ mineral composite transitions and structure formation during sintering at 900–1250 °C was accomplished using XRD, SEM, EDS, AAS, and LAMMA methods. All ceramics presented flexural resistance (until 10.08 MPa) in comparison with the values established in the Brazilian national standards (> 1.5 MPa), with low water absorption and shrinkage. Ceramics with 7% of the flotation waste and 10% spent foundry sand, whose resistance reached from 3.7 to 10.1 MPa, showed the best mechanical properties. Leaching and solubility analyses by AAS method showed that there is no environmental jeopardy in using these compositions to produce sustainable ceramics.

Protective and therapeutic effects of garlic and tomato on cadmium-induced neuropathology in mice

BackgroundHeavy metals are natural components of the earth’s crust and are considered as constant environmental pollutants since they cannot be degraded or destroyed easily. Cadmium (Cd) is present primarily in the ores of zinc, copper, or lead; the extraction and processing of which releases large quantities of cadmium into the atmosphere, hydrosphere, and soil thereby contaminating the human environment. The present study aimed to investigate the possible protective and therapeutic effects of garlic and tomato extract on cadmium-induced AChE activity, biochemical parameters along with the pathological changes in the brain tissue of mice.MethodsMale Swiss albino mice (n = 40) were divided into several experimental (protective and therapeutic) groups and were given single dose of cadmium (6 mg/kg bw) with supplementation of garlic (100 mg/kg bw) and tomato (50 mg/kg bw) extract for 15 and 30 days under protective and therapeutic study.ResultsCadmium-treated mice showed a significant decline in AChE (p < 0.01) level and total proteins (p < 0.0001) but a nonsignificant decrease in glycogen, cholesterol in the brain tissue activity as compared to control group. The histological study also showed degeneration in the form of vacuolation, congestion, hyperemia, lymphocytic infiltration, and edema in the brain (cortex and hippocampus) of Cd-treated mice. But the antioxidant-treated groups showed significant increment in AChE level and other biochemical parameters in the protective study. But there were significant variations in the therapeutic study, and this was also confirmed by the histological analysis of the brain. Both tomato and garlic administration showed more attenuation in the brain AChE activity, and it may be due to the strong antioxidant potential of their constituents.ConclusionWe can conclude that cadmium exposure should be avoided as it causes neuropathological effects. But in daily life, it may not be possible, so we should regularly intake natural antioxidants which may neutralize the effects of heavy metals to some extent.

Isotope systematics and fluid inclusion studies of the Hongtaiping Cu–Pb–Zn deposit in Yanbian, NE China: Implications for ore genesis

The Hongtaiping Cu–Pb–Zn deposit is located in the central part of the Yanbian–Dongning region, NE China, which is the eastern segment of the Central Asian Orogenic Belt. The Cu–Pb–Zn mineralization occurs in the contact zone of the Lower Permian Miaoling and Kedao formations with tuff lavas, tuffs, and marlstones as the principal host rocks. The orebodies are distributed in stratiform, stratiform‐like and lenticular morphologies, consistent with the host strata. Field investigations indicate three ore facies consisting of stringer–stockwork, massive, and laminated ores in the Hongtaiping deposit, which show apparent variation spatially from bottom to top of sulphide types. A lot of liquid‐rich fluid inclusions were identified in mineral crystals from the three types of ore facies with complete homogenization temperatures varying from 162 to 249°C and salinities in the range of 3.3 to 9.6 wt% NaCl equiv. The δD and values of calcite samples from the stringer or stockwork ores range from −82.0 to −75.1‰ and 3.3 to 3.7‰, respectively, lower than those (δD values of −64.1 to −38.8‰, values of −0.9 to 2.2‰) of the massive and laminated ores. In addition, the calcite samples show restricted δ13C values from −6.8 to −4.0‰. These fluid inclusions and H–O–C isotope geochemistry suggest that ore‐forming fluids of the Hongtaiping deposit were mainly sourced from heated seawater or brine derived, with the carbon from marine carbonates by water–rock interaction. The δ34S values of sulphide separates from the stringer–stockwork, massive and laminated ores range from −15.2 to −9.2‰ with an average value of −12.3‰. The sulphide minerals yield 206Pb/204Pb ratios from 18.025 to 19.758, 207Pb/204Pb ratios from 15.601 to 15.795, and 208Pb/204Pb ratios from 37.202 to 39.305. These S and Pb isotope compositions indicate that the sulphur had an origin in seawater sulphates from which sulphur was most possibly transformed into sulphide by thermochemical reduction, while the lead in ores originated mainly from the Miaoling Formation, with small amounts directly derived from the subvolcanic intrusion. Taken together, the Hongtaiping deposit can be classified as a volcanogenic massive sulphide (VMS) deposit, for which the possible mineralization process is interpreted in terms of a long‐lived convective circulation of mobile heated seawater mixed with some magmatic fluids along submarine faults and fissures during the Early Permian. The metals were migrated and subsequently enriched in the hydrothermal circulation system by being leached from the underlying volcanic rocks, with the metal‐rich ore‐forming fluids combined with contributions of water–rock reaction, thermochemical sulphate reduction and temperature change leading to the precipitation of polymetallic sulphides.

Controllable Synthesis of Lead Iodide Hexagonal Plate from Mixed Sulfide-oxide Lead and Zinc Ore for Efficient Perovskite Solar Cells

The hexagonal plate lead iodide (PbI2), with band gap energy of 2.31 eV, was firstly synthesized from mixed sulfide-oxide lead and zinc ore by an in-situ reduction-selective leaching-precipitation approach, and the recovery efficiency of lead reached 92.30%. When the formed PbI2 was used to fabricate a perovskite solar cell (PSC), the power conversion efficiency (PCE) reached 14.98%, equivalent to that of the PSC from specpure PbI2. This work developed a new process for high value-added utilization of the mixed ore.

Selective and efficient extraction of lead from mixed sulfide-oxide lead and zinc ore by the in-situ self-reduction method

Efficient and selective extraction of lead was realized from the mixed sulfide-oxide lead and zinc ore by an in-situ self-reduction method for the first time. The thermodynamic feasibility of reaction scheme which consisted of reducing PbO2 from Zn leach residue containing PbO2 to PbSO4 by pyrite (FeS2) and sphalerite (ZnS) coexisted in the mixed ore in sulfuric acid (H2SO4) medium, followed by leaching PbSO4 as Pb(Ac)42− ions using NH4Ac solution, was elucidated. The effects of experimental parameters on extraction of Pb were comprehensively studied. Results demonstrated that the Pb extraction efficiency could achieve a high value of 99.4%, and specifically, the Pb(Ac)42− solution contained only Pb and Ca ions without any other impurity, which was conductive to preparing functional materials. This paper provides a novel pathway for selective and efficient extraction of Pb from the mixed ore.

From Lead Paste to High-Value Nanolead Sulfide Products: A New Application of Mechanochemistry in the Recycling of Spent Lead–Acid Batteries

The recycling of lead in spent lead–acid batteries (LABs) is an effective measure to cope with the depletion of primary lead ore. In this study, multicomponent lead in the lead paste of spent LABs ...

The Prison of Public Works: Enslaved People and State Formation at Virginia's Chiswell Lead Mines, 1775–1786

The Prison of Public Works:Enslaved People and State Formation at Virginia's Chiswell Lead Mines, 1775–1786 Sean Gallagher (bio) One night in November 1775, an enslaved man named Charles stole an oyster boat at Aquia Creek in Stafford County, Virginia, and tried to sail to freedom. He and three other bondpeople took a couple of white fishermen hostage and demanded that they pilot the boat to the mouth of the York River, where the royal governor, John Murray, the fourth earl of Dunmore, was stationed. Charles had learned that Lord Dunmore had issued a proclamation offering freedom to all rebel-owned enslaved people who could reach his ship and would defend the Crown. Charles therefore made, in the words of his owner Robert Brent, "a determined resolution to get liberty." But the escape failed; the white fishermen sailed the boat into view of another ship and had the bondpeople placed under arrest. At their trial the following April, a county court loyal to the Patriot Committee of Safety in Williamsburg convicted Charles and the others of felony insurrection and sentenced them to "be hanged by the Neck until they be dead."1 Before the men's execution, however, the Committee of Safety commuted their executions to hard labor at the Chiswell lead mines in the southwest corner of the colony (in present-day Wythe County). In December 1776, Governor Patrick Henry of the newly independent state of Virginia issued ninety pounds from the treasury to Brent and purchased Charles for state use. Charles had no mining experience or skill in [End Page 777] the trade work necessary at mines such as blacksmithing or carpentry. He had "always" labored as Brent's personal servant. His "design" to selfemancipate, however, made him an ideal miner for Chiswell.2 Carted nearly three hundred miles west of Williamsburg, Charles extracted lead ore alongside other bondpeople and smelted it into musket shot for Continental army and militia troops. For the duration of the Revolutionary War, Charles worked as what was known as a "public negro," producing ammunition for his captors.3 The Chiswell lead mines were among the multiple works that Patriot institutions leased or subsidized at the outset of the war in order to supply munitions to militia troops.4 While most of these Patriot manufactories remained unbuilt in 1775–1776, the lead mines along the New River were already developed and indeed already possessed a workforce of free Welsh artisans and several bondpeople. John Chiswell founded the site in 1761, and by the Revolution it was owned by several prominent shareholders, including William Byrd III. The Fincastle County Committee of Safety, at the behest of Virginia's Third Convention, began renting the mines from private shareholders only a few months before Charles's escape. When Virginia's first state constitution went into effect in July 1776, the committee's lease transferred to Governor Patrick Henry and his executive council, just as the legislative functions of the provincial conventions passed to the House of Delegates. The House of Delegates empowered the governor to purchase bondpeople specifically for the mines. Militia officers—first, Colonel James Callaway and then, from December 1777 onward, Colonel Charles Lynch—superintended the works on the ground. With the exception of the period between May 1779 and June 1780, when the Virginia Board of Trade oversaw public works, the governor and council handled the Chiswell affairs either directly or through appointed commercial agents.5 [End Page 778] Patriot assemblies became state institutions when they incarcerated black runaways like Charles at sites of public labor like Chiswell. Of course, historians have long known that enslaved people's escapes and revolts at the height of the imperial crisis pushed their owners toward independence. As scholars from Sylvia R. Frey to Woody Holton have argued, when enslaved people triangulated the conflict with Britain by seeking the protection of royal governors, Patriot associations took up the mantle of upholding white supremacy.6 In effect, as Sally E. Hadden and Edward B. Rugemer have shown, the rage militaire of 1775 and 1776 was, in the southern colonies, the rejuvenation of the mid-eighteenth-century slave patrol and "Ordering" acts by independent...

Η μεταλλουργία της Πιστύρου και της περιοχής της κατά τους ιστορικούς χρόνους: η έρευνα και τα πρώτα πορίσματα

The metal production at Pistyros and the surrounding area in the historical period: Reserach and first results. This article focuses on metal production at the Thasian colony of Pistyros in Aegean Thrace during the Classical/Hellenistic periods. Evidence for mining activity in the Lekani Mountains, that was mentioned by ancient authors is also under examination. Mining shafts and galleries, mineral processing areas and slag heaps represent direct evidence for the organization and running of large-scale metal production in this region. With the foundation of Thasian colonies and emporia in the coastal zone, the output in metals increased and this became possible through the involvement of Thracian manpower as they were more numerous and better suited to exploit these resources. On the other hand, the Greeks of the colonies traded finished products in exchange for raw materials. This reciprocal relation is corroborated by recent evidence for metal production deriving from the ongoing excavation at Pistyros, namely large volumes of metallurgical slag. The archaeological findings reveal that primary smelting of iron/manganese ores bearing precious metals and argentiferous lead ores were smelted at Pistyros for the extraction of silver and possibly also gold. The coexistence of slag, speiss and litharge at Pistyros provide clues to the potential workflow for precious metals extraction. Thus, it is being suggested that three liquid layers formed within the same furnace: a) slag floating on the top, b) speiss separating in the middle and c) a layer rich in Pb/Ag collected at the bottom. The next stage would involve further treatment of the Pb/Ag product through cupellation for the separation of lead from silver during which platy litharge was formed, characteristic examples of which were found during excavation. The supply of raw materials, i.e. minerals and timber for charcoal, from the mining zone in the Lekani Mountains was a matter of negotiation and exchange between the indigenous Thracian miners and the Thasian populations of the colonies.

Historical evolution of lead-acid battery system and its relationship with external environment based on the composite flow

The quantitative demand for composite flow of lead-acid battery (LAB) system varies with the requirement from human and affects the external environment. A framework with four stages [production of primary lead (PPL), fabrication and manufacturing (F&M), use and waste management and recycling (WMR)] and the external dynamic evaluating system was developed. The historical evolution characteristics of the system in the Chinese mainland from 1990 to 2016 was investigated. For material aspect, the consumption of secondary lead increased faster. All lead ore was consumed in PPL and reduced by the average rate 1.2%. The total lead emissions declined before they increased, that in F&M reduced the most with the average rate 29%; the share of scrap lead in waste LAB was vital, 63%-75%. For energy aspect, the energy consumption in WMR grew faster. And the external performance of energy flow grew, that in PPL reduced the fastest with the average rate 31%, and the share of that in use was approximately 80%. For value aspect, the value of lead in LABs increased faster. The influence from the value flow grew negatively. The index of WMR increased the positively and fastest by average rate 85%, and its proportion of use was largest, about 313%. The evolution of the key internal factors was analyzed, which have a great influence on the system. The overall change of large recycling rate, intermediate recycling rate and lead emissions rate of WMR grew. The lead emissions rates of F&M and PPL increased before decreasing. The reasons influencing the variation, such as policies and technologies, were analyzed.

The Pb-Zn-Ag vein system at Montevecchio-Ingurtosu, southwestern Sardinia, Italy: A summary of previous knowledge and new mineralogical, fluid inclusion, and isotopic data

The Montevecchio-Ingurtosu district (SW Sardinia) was among the largest historical Pb-Zn producers of Italy, with significant Ag output, and yields of metallic byproducts such as Cd, Co, Cu, Bi, Sb, Ge, In, and Ga. Despite this importance, detailed descriptions of orebodies and mineral assemblages are surprisingly scarce and old. Here we summarize all previously available information and contribute new textural, microchemical, fluid inclusion, and C-O isotopic data deriving from a recent sampling of currently exposed orebodies. Mineralization occurs as steeply dipping veins extending for almost 20 km at the northern and western flanks of the Variscan Arbus pluton; veins are hosted in phyllites of the Arburese Unit close to the thermometamorphic aureole. Ore enrichments range from massive to coarsely nodular, stockwork and brecciated. Vein filling consists of siderite (locally Zn-rich), quartz, sphalerite, galena (remarkably rich in micro-inclusions), with accessory chalcopyrite, fahlore, bournonite, barite, and Ni-Co sulfarsenides. Vein assemblages may vary, even within a single vein, from sphalerite- to galena-dominated. Cu-rich assemblages (fahlore + chalcopyrite) were locally observed. Wallrock is affected by silicification, sericitization and pyrite dissemination. Sphalerite shows a complex mineral chemistry, with marked variations in Fe (0.08 to 8.9 mol% FeS) and in Cd contents (from <0.05 to >1 wt%). Trace element analyses (LA-ICP-MS) document the presence of measurable amounts of Ga, Ge, In, Ag, Ni, Co, Tl and Mo. Fahlore varies from the Sb (tetrahedrite) and the As (tennantite) endmembers, with Ag-rich compositions corresponding to Sb endmembers. The occurrence of Cd-rich tetrahedrite (up to 14.5 wt%) is remarkable. Fluid inclusion studies on sphalerite and quartz are in agreement with previous literature data, and indicate comparatively low (in the range 90°–130 °C) homogenization temperatures (Th) and high salinities (14 to 25 equiv. mass % NaCl); both microthermometric data and SEM/EDS analyses of decrepitated inclusions indicate the presence of Ca and K beside Na. Pressure correction to Th is presumably low (in the order of 10 °C), considering a hydrostatic pressure regime. Application of the sphalerite-based GGIMFiS thermometer provided temperatures in excellent agreement with fluid inclusion data for the Montevecchio mineralization. Isotopic data on Montevecchio carbonates define mildy negative δ13CPDB values (between −1 and −5 per mil), and a larger spread of δ18OSMOW values, between +14 and +20 per mil. Other isotopic data from literature include a limited set of δ34S values for galena, sphalerite and pyrite, and a fairly large body of Pb isotopic data on galena. Comparatively narrow ranges for sulfur isotope signatures suggest a homogeneous, possibly igneous, sulfur source, whereas the large spread in Pb isotope signatures reflects the large-scale character of the hydrothermal process and indicates that the Arbus pluton may have been just one of the sources of ore lead. The Montevecchio vein system shows affinities with other late to post Variscan European deposits. The nature of the mineralizing fluids at Montevecchio is analogous to low temperature, basinal brines, and typical of several regional-scale, late to post-Variscan hydrothermal events across Europe. Mineralization at Montevecchio obviously postdates the emplacement of the Arbus plutonic complex, but its exact age remains unknown..

The history of mining and metallurgy of metal ores in upper Silesia preserved in metallurgical waste dumps

Abstract The history of mining and metallurgy in Upper Silesia dates back to the early Middle Ages. Initially, appearing on the surface, calamine, i.e. oxidized zinc-lead ores, and limonite – iron ore were used. The development of mining technology allowed for exploitation of ore deposits at greater depths. It contributed to the intensive development of industry at the turn of the 19th and 20th centuries. At that time, one of the most important industrial settlements was today's Ruda Śląska. In its area, apart from hard coal mines, there were several forges processing locally exploited zinc, lead and iron ore. The testimony of the former mining and metallurgy, among others, is the dump, which is a remnant of the Hugo zinc smelter (1812-1932). Mineralogical and chemical analyzes of waste material collected on the dumping ground provide a lot of interesting information about the processed raw material.

A Detailed study of Applying Gravity Separation to Lead and Zinc Carbonate Ore for Smithsonite Concentration Using DMC

ABSTRACT Gravity separation of a low-grade lead and zinc carbonate ore (case study: Angouran mine, Zanjan, Iran) was investigated based on detailed laboratory and modeling studies. The authors used two types of laboratory sink-float evaluations with single density and multiple densities to demonstrate the effectiveness of Dense Medium Cyclone (DMC) as a new application to separate lead and zinc minerals, in particular, zinc carbonate (Smithsonite) from silica and limestone gangue. The laboratory tests included determining floats from five to six density intervals that descended between the densities of the light and heavy minerals. In addition, the authors used MODSIMTM process simulation software to determine the optimum separating density, zinc grade of concentrate and tailings products, yield and metal recovery. The results showed the possibility of successful gravity separation of the ore. To optimize DMC gravity separation operation in the plant, the circuit was sampled and the effect of important parameters influencing separation performance was studied. The separation efficiency (sharpness) and plant performance to separate valuable minerals were determined by estimating the partition curve for the particle size distribution limited to 0.5–5.6 mm range. The performance indicating parameters including the short circuit fractions to sinks and floats, the separation sharpness and the separating density were estimated to be equal to 0.0116, 1.5885, 20.4 and 3.18, respectively, using the non-linear optimization tool of Excel (Solver) based on least squares method.

Assessment of a Nigerian lead ore potential for industrial value additions by sulfamic acid solution

The potential of a Nigerian lead ore in form of galena and anglesite containing 72.82 wt% Pb, 19.95 wt % S, 3.07 wt% Au and 2.77 wt% As, as major elements was treated by sulfamic acid (H3NSO3) solution. The influence of acid concentration, reaction temperature, stirring speed and particle size on the extent of ore dissolution were properly determined. From the results obtained, the dissolution of lead ore increases with increasing H3NSO3 concentration, reaction temperature, stirring speed and decreasing particle size. At a set of experimental conditions (0.75 mol/L H3NSO3, − 70 + 90 µm, 320 rpm, 70 °C), 68.2% of the initial 10 g/L ore reacted within 120 min. The calculated apparent activation energy of 28.35 kJ/mol with reaction order of 0.758 confirmed and supported the proposed diffusion controlled mechanism for the dissolution process appeared to be first-order relation. The leach liquor at optimal conditions as analyzed by atomic absorption spectrophotometry were found to contain 2861 mg/L (68.2%) Pb2+, 270 mg/L (6.44%) Fe2+ and 185 mg/L (5.34%) Zn2+ as major species.