Estimation of lead and zinc emissions from mineral exploitation based on characteristics of lead/zinc deposits in China

Nonferrous mining activities are some of the largest sources of heavy metals emissions into the environment and China is one of the largest producers and consumers of lead and zinc in the world.The cumulative productions and emissions of lead and zinc from mining-related activities in China were estimated.Up to 2007,the cumulative productions of lead and zinc in China were estimated to be about 6.69 and 12.59 Mt,respectively;and about 1.62 Mt lead and 3.32 Mt zinc emitted into the ambient environment during the mining,processing and smelting activities,representing 24.39% and 26.36% cumulative production,respectively.Among these three types of mining-related activities,mineral processing contributes the most to the total emission of 50.67% lead and 45.51% zinc.

Heavy metal concentrations in soils and plants in the vicinity of Arufu lead-zinc mine, Middle Benue Trough, Nigeria

This study focused on the influence of base metal mining on heavy metal levels in soils and plants in the vicinity of Arufu lead-zinc mine, Nigeria. Soil samples (0-15 cm depth) and plant samples were collected from cul-tivated farmlands in and around the mine, the unmineralized site and a nearby forest (the control site). The samples were analyzed for heavy metals (Fe, Zn, Mn, Cu, Pb, Cr and Cd) by Atomic Absorption Spectrophotometry (AAS). The physical properties of soils (pH and LOI) were also measured. Results showed that soils from cultivated farm-lands have neutral pH values (6.5-7.5), and low organic matter contents (<10%). Levels of Zn, Pb and Cd in culti-vated soils were higher than the concentrations obtained from the control site. These heavy metals are most probably sourced from mining and agricultural activities in the study area. Heavy metal concentrations measured in plant parts decreased in the order of rice leaves>cassava tubers>peelings. In the same plant species, metal levels decreased in the order of Zn>Fe>Mn>Cu>Pb>Cr>Cd. Most heavy metals were found in plant parts at average concentrations normally observed in plants grown in uncontaminated soil, however, elevated concentrations of Pb and Cd were found in a few cassava samples close to the mine dump. A stepwise linear regression analysis identified soil metal contents, pH and LOI as some of the factors influencing soil-plant metal uptake.

Analysis and Evaluation of Bioavailable Heavy Metals in Surface Soil of the Abandoned Lead-zinc Mine in Changhua,Hainan Province

[Objectives] The research was conducted to study characteristics of bioavailable levels pollution of heavy metals in the surface soil of the lead-zinc mine in Changhua.[Methods] A total of 56 surface samples were collected from the 3 study zones （peripheral zone, reclamation zone and tailing zone） located at the lead-zine mine in Changhua. Based on total and bioavailable heavy metals （Pb, Zn, Cu and Cd） in soils, the correlation of total content with bioavailable content was analyzed, and their pollution characteristics were assessed by methods of single factor pollution index, Nemerow pollution index, geological accumulation index and potential ecological risk index.[Results] （i） The surface soils were polluted by Pb, Zn, Cu, Cd in different degrees, and the overall trend of the contents of the 4 heavy metals was in order of Cd 〉 Pb 〉 Zn 〉 Cu. The average excess multiple of heavy metals of total and bioavailable content in soils were in the order of peripheral zone 〉 tailing zone 〉 reclaimed zone, and their pollution degrees were tailing zone 〉 peripheral zone 〉 reclaimed zone. （ii） In general, the total and bioavailable contents of Pb, Zn, Cu, Cd showed a significant correlation, but were not correlated in each study zone. （iii） Pollution degrees of the study zones were in the order of tailing zone 〉 peripheral zone 〉 reclamation zone. The pollutions of heavy metals Pb and Cd were more serious, especially Cd reached high levels of pollution degree, and the pollution degrees of Zn, Cu were lighter. Contributors of ecological risk were mainly Cd, Pb and Cu, and the contribution of Cd achieved more than 90 %, making it the main source of pollution.[Conclusions] The results not only revealed the pollution status of heavy metals in the surface soil of the abandoned coal mine, but also could provide scientific guidance for reasonable utilization and ecological recovery of the land.

Analysis of Oxygen Consumption in Lead and Zinc Metallurgy

This article analyzes the role of oxygen in lead zinc metallurgy,including shortening the metallurgical process,promoting energy conservation and environmental protection,improving metallurgical strength,enhancing raw material adaptability,and enhancing comprehensive recovery efficiency.This article introduces different lead zinc metallurgical processes and their oxygen consumption characteristics,including oxygen enriched side blowing lead smelting,oxygen bottom blowing lead smelting,oxygen enriched top blowing lead smelting,flash smelting lead,oxygen pressure leaching zinc smelting,and atmospheric pressure oxygen leaching zinc smelting.It is pointed out that oxygen enhanced metallurgy is the direction for the transformation and upgrading of lead zinc metallurgy.

Feasibility of Simultaneous Application of Fuzzy Neural Network and TOPSIS Integrated Method in Potential Mapping of Lead and Zinc Mineralization in Isfahan-Khomein Metallogeny Zone

Iran is located on a silver, lead, and zinc belt and according to the latest studies holds 11 million tons of lead, zinc, and silver stones which constitute 4 percent of global resources. Considering that mineral materials are explored in an uncertain space, exploration investment risk is an inseparable part of these activities. The important fact is to minimize the effect of this undesired factor in exploration. To achieve this, it is required that exploration activities and withdrawals are performed in a certain framework in which risk minimization is considered. Using mineral potential modelling for determining promising zones which should be taken into consideration in more detailed stages could make achieving the purpose possibly. This work is aimed at applying fuzzy neural network and TOPSIS methods simultaneously in order to explore zinc and lead resources. In this article, geological, telemetry, geophysics, and geochemistry data is integrated using fuzzy-neural network (neuro fuzzy) and using TOPSIS method rating for lead and zinc ore deposit potential mapping in Isfahan-Khomein strip which has been introduced as one of zinc and leads mineral scopes in Iran. This area which is composed of several zinc and lead ore deposits has been considered as the target area. Fuzzy integration results of zinc and lead mineralization witness layers confirm the relatively high potential of lead and zinc mineralization in this region having a northwest-southeast trend and involving more than 90 percent of the known indices and ore deposits of the region. In this research, it was shown that the results of TOPSIS-Neuro-Fuzzy integrated model (a combination of neural network and fuzzy logic) have increased the resolution of talented areas from the areas with no mineralization potential in comparison with the fuzzy method individually.

New Constraints on the Environmental Impact of Iron Oxides and Lead-Zinc Mines in Red Sea Hills,Egypt

Iron oxides and lead-zinc deposits in host rocks located in ten drainage basins in the coastal plain of the Red Sea,Egypt,have been subjected to important mining activities.The drainage basins were analyzed to estimate the transportations of these minerals. Fourteen soil samples and fifteen plant samples were collected from sites located in the basin and also in neighboring area and chemically analyzed.In

Sulfidation roasting of lead and zinc carbonate with sulphur by temperature gradient method

In order to enhance the lead and zinc recovery from the refractory Pb-Zn oxide ore, a new technology was developed based on sulfidation roasting with sulphur by temperature gradient method. The solid-liquid reaction system was established and the sulfidation thermodynamics of lead and zinc carbonate was calculated with the software HSC 5.0. The effects of roasting temperature,molar ratio of sulphur to lead and zinc carbonate and reaction time in the first step roasting, and holding temperature and time in the second roasting on the sulfidation extent were studied at a laboratory-scale. The experimental results show that the sulfidation extents of lead and zinc are 96.50% and 97.29% under the optimal conditions, respectively, and the artificial galena, sphalerite and wurtzite were formed. By the novel sulfidizing process, it is expected that the sulphides can be recovered by conventional flotation technology.

Order of sphalerite and galena precipitation: A case study from lead-zinc deposits in southwest China

Most of the lead and zinc deposits in Southwest China, are characterized by mineral zoning, which is especially true for the Huize and Zhaotong deposits. The mineral assemblage zoning is consistent for both horizontal and vertical zoning, from the base(center) of the ore body to the top(outermost), the mineral zones are as follows. I-1: coarse-grained pyrite and a little puce sphalerite;I-2: brown sphalerite, galena, and ferro-dolomite;I-3: galena, sandy beige and pale yellow sphalerite, and calcite;and I-4: fine-grained pyrite, dolomite, and calcite. Among them, sphalerite is the landmark mineral of different zoning. From I-1 to I-3, the color of sphalerite changes from dark to light, its crystalline size changes from coarse to fine, and its structure changes from disseminated to veinlet. This mineral zoning is seen not only on a microscopic scale, but is also clear on a mesoscopic and macroscopic scale. It is caused by the order of the sphalerite and galena precipitation. We studied the metallic minerals and fluid inclusions using a thermodynamic phase diagram method, such as lgfO2–lgfS2, pH–lgfO2, pH–lg[Pb^2+] and pH–lg[HS^-], discussed the constraints on the order of the sphalerite and galena precipitation in the migration and precipitation process of lead and zinc under different pH values, oxygen fugacity, sulfur fugacity, and ionic activity. We also explain the formation mechanism and propose that the main controlling factor of the order of the sphalerite and galena precipitation is sulfur fugacity.

Local Structure Analysis of Lead Zinc Niobate-Barium Titanate Ceramic by X-Ray Absorption Spectroscopy and Density Functional Calculation

The local structure of an alternative Pb（Zn1/3Nb2/3）O3-based perovskite ceramic is investigated. The 0.07BaTiO33-0.93Pb（Zn1/3Nb2/3）O3 ceramic is synthesized using a combination of Zn3Nb2O8 B-site precursor and BaTiO33 perovskite phase stabilizer. Then, x-ray absorption spectroscopy and density functional theory are employed to calculate the local structure configuration and formation energy of the prepared samples. Ba2＋ is found to replace Pb2＋ in AA-site with Zn2＋ occupying BB-site in Pb（Zn1/3Nb2/3）O3, while in the neighboring structure, Ti4＋4＋ replaces Nb5＋5＋ in BB-site with Pb2＋2＋ occupying AA-site. With the substitution of BaTiO33 in Pb（Zn1/3Nb2/3）O3, the bond length between Zn2＋ and Pb2＋ is longer than that of the typical perovskite phase of Pb（Zn1/3Nb2/3）O3. This indicates the key role of BaTiO33 in decreasing the steric hindrance of Pb2＋ lone pair, and the mutual interactions between Pb2＋ lone pair and Zn2＋ and the formation energy is seen to decrease. This finding of the formation energy and local structure configuration relationship can further extend a fundamental understanding of the role of BaTiO33 in stabilizing the perovskite phase in PbZn13Nb23O3-based materials, which in turn will lead to an improved preparation technique for desired electrical properties.

THE METALLOGENIC STRUCTURE OF VEIN-SHAPED LEAD-ZINCDEPOSIT IN HENGSHANLING-SHEXINGPING,CHENZHOU,HUNAN

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Qinling-Type Lead-Zinc Deposits

Qinling-type Pb-Zn deposits are located in the Qinling fold belt, occurring in the fine-clastic and carbonate rocks of the Devonian marine facies. They are reformed sedimentary deposits originating from hydrothermal waters, and may be subdivided into 2 subtypes: hydrothermal sedimentary deposits (Changba subtype) and reformed hydrothermal sedimentary deposits (Bijiashan-Qiandongshan subtype). In comparison with some of the famous Palaeozoic Pb-Zn deposits in the world, the Qinling-type Pb-Zn deposits constitute an independent type, which possesses some characteristics of both hydrothermal sedimentary deposits (Meggen type) and reformed hydrothermal deposits (Mississippi Valley type).

旬阳铅锌矿带地质环境问题现状及治理对策

旬阳铅锌矿带铅锌矿资源多年粗放式开发,导致地质环境问题逐步显现,主要表现为由采矿活动引发的地质环境污染、矿山土地资源损毁及矿山地质灾害隐患等。对旬阳铅锌矿带环境问题现状进行了详细分析和总结,并提出相应的地质环境治理对策。

典型铅锌矿区周边土壤-稻米重金属污染特征及健康风险评价

为了掌握黔西北典型铅锌矿区周边稻田土壤重金属污染状况,分别采集98个土壤样品和稻米样品,运用单因子污染指数法、内梅罗综合污染指数法和潜在生态危害指数法对研究区稻田土壤中八种重金属(Cr、Ni、Cu、Zn、Cd、Pb、Hg、As)进行污染特征分析和风险评价,并采用健康风险评估模型对研究区稻米进行健康风险评价。结果表明:研究区稻田土壤受到重金属不同程度污染,整体处于中度污染水平(P_(N)=2.61),但Cu为重度污染(P_(Cu)=3.13);土壤生态风险总体处于中等水平(RI=279),最主要生态风险因子为Hg,其生态风险危害程度为很强(E_(Hg)=179);研究区稻米中重金属平均含量未超标,但有部分点位样品重金属含量超标;食用研究区种植的稻米不会对成人和儿童引起单一重金属健康风险,但长期食用,多种重金属复合污染会对成人和儿童健康产生负面影响(THQ_(成人)=2.41,THQ_(儿童)=2.48)。

三维激电法在黔西北某铅锌矿勘查中的应用

黔西北铅锌成矿区是贵州省重要的铅锌产地之一,区内发现的某超大型铅锌矿深部及外围被认为仍具较大找矿潜力。随着埋深加大,地质条件更复杂,通过地球物理方法探查直接或间接的矿致异常愈加被认可。为研究三维激电方法在黔西北铅锌成矿区的勘查效果,首先在典型矿床开展了方法有效性及装置参数试验,结果显示梯度四极加三极装置联合反演显示的高极化率(17~20 mV/V)、低电阻率(158~251Ω·m)与已知铅锌矿体空间位置对应较好,然后应用到外围空白区,圈定了高极化、低电阻激电异常,经钻孔验证为含黄铁矿及铅锌矿(化)地质体。表明通过低电阻率高极化率圈定含黄铁矿物地质体异常,结合地质分析,间接指示铅锌矿体空间位置是本区三维激电方法应用的思路,对地区同类型铅锌矿地球物理勘探具有参考意义。

铅锌矿废石产酸潜力及模拟强酸雨环境下重金属淋溶规律分析

这是一篇矿山生态修复领域的论文。矿山开发过程中不可避免产生大量废石,废石中重金属元素在风化、淋溶等作用下释放,将对矿区周边水土环境质量产生影响。为了研究某铅锌矿废石重金属元素淋溶规律,分析了该废石的化学组成和产酸潜力。模拟强酸雨环境下,分析了废石中重金属元素溶出率及淋溶前后废石的矿物组成。结果表明:该废石中重金属Cu、Pb、Zn、Cd、As元素无独立矿物,在废石中分散赋存;废石酸中和能力较高,净产酸量NAG为0 kg H_(2)SO_(4)/t,无产酸潜力。在模拟强酸雨淋溶实验中,淋出液pH值均呈弱碱性,这与废石含较多的碱性矿物有关,废石具有一定的酸缓冲能力;第1轮淋溶过程Cu、Pb、Zn、Cd、As元素随淋溶时间延长累积溶出率逐渐升高;第2轮淋溶2周期后Cu、Pb、Zn、Cd元素累积溶出率趋于稳定,后续基本不溶出;As元素累积溶出率随淋溶时间延长而升高;总体而言,废石中重金属溶出率低。废石淋溶前后矿物成分不变,矿物含量略有变化。本文可为矿山废石堆场管理及其周边重金属污染防治提供依据。

开放系统下铅锌对地质碳汇的影响研究

自工业革命以来,资源需求量不断增加,矿产资源被过度开采引起一系列地质环境问题,针对采矿学者研究主要集中在地质环境灾害、矿山的修复技术方法和采矿暴露出的重金属对人类身体健康造成的危害等方面,鲜有学者研究采矿中重金属元素与地质碳汇的关系,随着双碳目标成为国家战略,重金属与地质碳汇机理研究对双碳战略目标有重要的科学意义。本文通过研究不同岩样在不同浓度铅、锌溶液中的溶解特征来探究开放系统条件下铅锌对地质碳汇的影响,研究发现:(1)随着实验时长的增加,所有组别的pH值呈下降趋势,电导率呈上升趋势。(2)0.5 mg/L的铅溶液可能会抑制岩石的溶解,HCO_(3)^(-)的浓度在第10天时突然变大随后又逐渐减小,而当加入灵川县铅锌矿场的铅锌矿粉末后溶液中HCO_(3)^(-)浓度倍增。0.1 mg/L铅溶液中加入铅锌矿粉末后,其水溶液中的HCO_(3)^(-)浓度明显少于未加入铅锌矿粉末的对照组。故认为铅可能作为抑制剂影响岩样在溶液中的溶解。(3)在1和5 mg/L锌溶液中加入铅锌矿粉末,无论其浓度高低,灰岩、角岩和灰岩+角岩3个实验组别HCO_(3)^(-)浓度将明显高于未加入铅锌矿粉末的对照组,故认为锌可能起催化作用。(4)通过对干燥后的岩样进行非原位SEM图像扫描发现,无论低浓度还是高浓度铅溶液,其溶蚀坑较无铅溶液明显增多,溶蚀台阶也明显呈无规则状,但在高浓度的铅溶液中更加突出,并且伴随着置换反应的发生,由低浓度到高浓度的铅溶液中可以观察到一些孔隙的发展和裂缝的形成。

石灰与生物炭对污染土壤理化性质、万寿菊生长与镉铅含量的影响

土壤镉铅污染已成为我国主要的环境问题,严重威胁着农业的可持续发展.因此,亟需探索经济、有效的土壤修复技术.采用云南兰坪铅锌矿周边重金属污染的农田土壤开展盆栽试验,研究石灰(2.0 g·kg^(-1))与生物炭(20.0 g·kg^(-1))对土壤理化性质、万寿菊(Tageteserecta L.)生长与镉铅累积的影响.结果表明:(1)石灰和生物炭均显著增加土壤pH、碱解氮含量、株高与生物量,单施生物炭还显著增加土壤速效钾含量,导致植株氮磷钾养分含量降低;(2)石灰和生物炭会降低土壤弱酸提取态镉、可还原态铅的含量,增加残渣态镉铅含量,有效态镉含量分别降低23.4%和17.6%,有效态铅含量分别降低32.4%和21.8%;(3)石灰和生物炭降低万寿菊植株镉铅含量与累积量,植株水溶态镉、氯化钠提取态铅含量降低,残渣态镉、铅含量增加,并显著降低万寿菊镉铅富集系数;(4)石灰和生物炭增加万寿菊菊花产量与叶黄素含量,导致叶黄素提取液的铅含量分别降低37.6%和30.3%;单施石灰导致叶黄素提取液的镉含量降低49.3%.可见,石灰和生物炭能改善污染土壤理化性质,降低土壤镉铅有效性与万寿菊植株镉铅含量,促进万寿菊生长,增加菊花产量,促进重金属污染农田的安全利用.

青海某铜铅锌多金属矿选矿工艺研究

针对青海某铜铅锌多金属矿,进行了不同类型捕收剂对铜铅锌浮选分离影响的试验,重点考察了新型捕收剂4037B、P5100C、QBSC的选别效果。结果表明:P5100C和QBSC更有利于铜、铅分离,在最佳条件下,采用铜快速浮选—铜铅混选—铜铅再磨分离—锌浮选流程,获得铜品位35.56%、铜回收率75.23%的铜精矿;铅品位45.02%、铅回收率71.92%的铅精矿;锌品位41.49%、锌回收率72.58%的锌精矿;含铜20.14%、含铅8.90%、含锌28.38%,铜回收率11.93%、铅回收率6.77%、锌回收率11.81%的混合精矿。全流程铜总回收率97.94%,铅总回收率96.62%,锌总回收率92.64%。