MANTLE SOURCE NATURE OF ORE FLUIDS FOR THE JINDING Pb-Zn DEPOSIT, LANPING, YUNNAN

Geological setting\;Jinding superlarge Pb\|Zn deposit lies in the Lanping basin between the Lancangjiang fracture zone and the Jinshajiang\|Ailaoshan fracture zone. The Lanping basin is a Meso\|Cenozoic rifting basin whose basement consists of the Paleozoic strata. Mesozoic paralic and continental sediments with a thickness of about 20000m deposited in the basin. In the Paleocene, gypsum\|salt\|bearing strata with a thickness of more than 1000m accumulated. In the Cenozoic, collision of the Indian plate with the Eurasian plate resulted in strong folding and napping and subsequent extensions in the Oligocene and Pliocene. The extensions were responsible for alkaline magmatic intrusion in the centre and alkaline magmatic extrusion in the east.Faulting is well developed. N\|S\|trending Bijiang fault with a length of 120km links with the Jinshajiang fracture zone in the north and with the Lancangjiang fracture zone in the south, controlling on the Cenozoic Lanping rifting basin and acting as passage\|way for ore fluids.

Geochronology and geochemistry of magmatic rocks in the Dongzi–Changhanboluo Pb–Zn ore district in Chifeng,Inner Mongolia,and their relationship with metallogenesis

Bulk-rock elements,isotopes,and zircon U–Pb ages are reported for magmatic rocks in the Dongzi–Changhanboluo Pb–Zn ore district in Chifeng,Inner Mongolia,China.Zircon U–Pb dating identified four stages of magmatism:Late Silurian gabbroic diorite(*420 Ma),Middle Permian monzonite(*274 Ma),Late Jurassic quartz porphyry and ignimbrite,breccia tuff(153–158 Ma)and Early Cretaceous andesitic porphyrite(*127 Ma).Integrating field observations,geochronology,and element and isotope geochemistry indicated a complex petrogenetic history of the magmatic rocks.The gabbroic diorite may have been sourced from EM1-type mantle.The source of the monzonite may have been mantle metasomatized by melt from the subducting plate.The Jurassic volcaniclastic rocks formed in a medium-pressure,high-temperature environment,possibly in the background of crustal thickening in a syncollisional stage and an early postcollisional stage.During this process,shaly sedimentary rocks were brought into the deep crust and heated,followed by the rapid isostatic uplift of the crust,which caused partial melting of the sedimentary rocks.Quartz monzonite porphyry and quartz porphyry formed by partial melting of mantle metasomatized by subducted sediments,but the quartz porphyry experienced high-degree differentiation and evolution.The andesitic porphyrite has characteristics similar to those of Permian monzonite,indicating that its source area was also the zone of mantle metasomatized by subducted sediment.The late Silurian and Permian magmatic rocks in this area most likely formed against a continental arc background related to the subduction of the Paleo-Asian Ocean Plate beneath the North China Plate.The Late Jurassic magmatic rocks suggest that the northern margin of the North China Craton may have been in a postcollisional setting during the Late Jurassic,with no obvious crustal thinning.The Cretaceous andesitic porphyrite may have formed against the background of lithospheric extension and thinning.According to the comprehensive analysis of geological characteristics,diagenetic and metallogenic epochs,and Pb isotope data,the formation of ore bodies in the Dongzi–Changhanboluo ore district was closely related to the Jurassic quartz porphyry.

Characteristics of the ore-forming fluid in the Huayuan Pb-Zn ore filed, Northwest of Hunan Province, China

1 Geological Setting The Huayuan Pb-Zn ore field in Xiangxi is located in the southeastern margin of the Yangtze block and the mid-segment of the West Hunan-West Hubei metallogenic belt.The exposed stratum are the lower

The Forming Conditions of and Ore-searching Direction for B, Mg,Pb, Zn and Au Deposits in the Liaoji Proterozoic Rift

The Liaoji Proterozoic rift is an inter-intracontinenatl rift developed from Archean granite-greenstone tectonic regime and contains many important mineral deposits of U, B, magnesite, Pb-Zn, Au, Ag, Co and P. These deposits were formed as the result of late mobilization, transportation and concentfation of the previously enriched ore-forming mate- rials in several ore-bearing formations formed during the rift stage. So the metallogeny of these deposits in the rift shows both inheritance and new generation of the ore-forming materials. In future ore-searching practice, attentions should be paid on the studies of the ore-bearing formations in the rift, on the multiple stages of metallogeny and and on multiple derivations of the ore-forming materials.

Pb,Cu和Zn在自然水体生物膜中铁/锰氧化物等组分上的富集规律

用选择性萃取法萃取天然基质采集的生物膜中的铁/锰氧化物,考察生物膜上铁/锰氧化物对水体中Pb,Cu及Zn的富集作用.结果表明,锰氧化物对生物膜富集Pb起主要作用,而铁氧化物和除铁/锰氧化物以外的以有机质为主的其它组分的作用很小;膜上其它组分对Cu的富集贡献较大,锰氧化物的贡献与铁氧化物的接近;锰氧化物对Zn的富集贡献最大,铁氧化物和其它组分的贡献比较接近.锰氧化物对Pb,Cu及Zn的富集能力分别高于铁氧化物的富集能力,铁氧化物和锰氧化物对3种金属富集能力的大小顺序分别是Zn>Cu>Pb和Zn>Pb≥Cu.

Genesis of the Maoping carbonate-hosted Pb–Zn deposit,northeastern Yunnan Province,China:evidences from geology and C–O–S–Pb isotopes

The Maoping Pb-Zn deposit(~3 Mt Pb+Zn reserves with grades of 12-30 wt%)is one of the largest Pb-Zn deposits in the Sichuan-Yunnan-Guizhou(SYG)metallogenic province,which has contributed a tremendous amount of lead and zinc resources for China.To obtain a further understanding of the sources of ore-forming materials and ore genesis of the deposit,S-Pb isotopes of sulfides and C-O isotopes of ore-stage calcites were systematically collected from representative orebodies at different elevations with a Finnigan MAT-253 mass spectrometer.The calcites separated from the sulfides of the NoⅠand NoⅡorebodies shared identical b13 CPDB values(-5.3 to-0.8‰)andδ18OSMOW values(+14.5 to+21.8‰)with those of the calcites in the SYG region,suggesting that CO2 in regional ore-forming fluids possibly had a homologous C-O source that originated from a ternary mixture of the dissolution of marine carbonate rocks,degassing process of the Emeishan mantle plume,and dehydroxylation of sedimentary organic matter.The No.Ⅰ-1 and No.Ⅰ-2 orebody was hosted in the same strata,but the sulfur source of No.Ⅰ-1 orebody(+13.1 to+19.0‰)with equilibrated sulfur fractionation(δ34Sspbaierite-<δ34Sgalena)and No.Ⅰ-2 orebody(+18.0 to+21.8‰)with sulfur equilibrium fractionation(δ34Sspnaierite>δ34-Sgalena)were different.They were derived from the allopatry thermochemical sulfate reduction(TSR)of overlying Carboniferous sulfates in the ore-hosting strata and local TSR of sulfates in the ore-bearing Upper Devonian Zaige Formation,respectively.The narrow and uniform Pb isotopic ratios of single galena grains collected from sulfides with 206Pb/204Pb of 18.713-18.759,207Pb/204Pb of 15.772-15.776 and 208Pb/204Pb of39.383-39.467 indicate a well-mixed metal source(s)that consist of Proterozoic Kunyang and Huili Group basement rocks and Devonian to Middle Permian ore-hosting sedimentary rocks.Besides,the late Permian Emeishan basalts are difficult to contribute metals for regional Pb-Zn mineralization despite a closely spatial relationship with the distribution of the Pb-Zn deposit.This is supported by Pb isotopic ratios plotting above the average upper crustal Pb evolution curves and staying far away from that of the agecorrected Emeishan basalts.Hence,taking into account of the similarities in tectonic setting,ore-hosting rock,ore assemblage,wall rock alteration,ore-controlling structure,and ore-forming materials and the differences in relationship with regional magmatism,fluid inclusion characteristic and ore grade between the Maoping deposit and typical MVT Pb-Zn deposit,the ore genesis of the Maoping deposit should be an MVT like Pb-Zn deposit.

铅、镉和锌污染对芦苇幼苗氧化胁迫和抗氧化能力的影响

对Pb, Cd和Zn胁迫下芦苇幼苗叶片和根内超氧阴离子自由基(O2-)和过氧化产物丙二醛(MDA)的含量、电解质渗漏以及超氧化物岐化酶(SOD)和过氧化物酶(POD)活性进行了研究. 结果表明,受3种重金属的影响,叶片和根内O2- 积累,MDA含量增加,伴随着电解质渗漏增大,显示发生了膜脂过氧化,细胞膜系统遭到破坏;作为植物抗氧化系统中的关键酶,SOD和POD活性高于对照,说明在重金属胁迫下芦苇幼苗体内的抗氧化能力增强. 可见,在重金属污染下细胞内O2- 浓度升高带来的膜脂过氧化增强是重金属伤害植物的主要原因;而保护酶系统SOD和POD活性的升高则可能是芦苇抗过氧化的机理之一.

豫西某难选铅锌矿选矿试验研究

豫西某铅锌矿有用矿物共生关系密切、嵌布粒度较细,采用铅锌等可浮、铅锌分离-硫化锌浮选-氧化铅浮选工艺,成功实现了该矿的铅锌回收与分离,并有效回收了氧化铅矿物,最终获得了铅品位、回收率分别为58.95%、68.67%的铅精矿和锌品位、回收率分别为48.67%、66.06%的锌精矿。

复杂铜铅锌硫化矿试验研究

某复杂铜铅锌硫化矿,铜铅锌共生关系密切,且都存在不同程度的氧化,分离难度较大。依据矿物特性,采用铜铅混浮-铜铅分离-浮铜铅尾矿浮锌的流程,在铜品位0.52%、铅品位1.50%、锌品位1.05%的条件下,取得了铜品位21.87%、回收率67.58%,铅品位43.29%、回收率72.04%,锌品位42.26%、回收率66.89%的指标,达到了综合回收铜铅锌矿物的目的。

真空碳热还原处理低品位氧化铅锌矿热力学分析及实验研究

针对低品位氧化铅锌矿开展了真空碳热还原提取锌的研究。通过热力学计算,得出ZnO被C还原的化学反应自由能和还原反应临界温度,当系统压力从101.3 kPa,依次降低为20.26,2.026,0.203,0.020,0.002 kPa时,所对应的还原反应临界温度从1 221 K依次降低为1 080,915,795,703和631 K。在多级冷凝真空炉内,温度为1 173 K时真空蒸馏处理低品位的氧化铅锌矿1 h,获得纯度为99.42%以上的金属Zn,Zn回收率达到95.68%。

硫酸-氯盐法浸出高铟氧粉酸浸渣中铜锌铅的试验研究

通过分析高铟氧粉酸浸渣的成分和物相特征，发现其主要物相为Cu2 FeS2、ZnSO4、ZnS和PbSO4，由于成分复杂，单一方法无法有效回收铜、锌、铅，因此设计了硫酸-氯盐二段浸出法，分别提取酸浸渣中铜、锌和铅。一段浸出采用硫酸浸出，在始酸浓度60 g/L，液固比5∶1，氧化剂高锰酸钾用量4％，浸出温度60℃条件下，浸出2 h，铜和锌浸出率分别达到84．29％和92．02％；二段浸出采用氯盐浸出，在NaCl浓度300 g/L，液固比10∶1，pH＝1．5～2．0，浸出温度90℃条件下，浸出60 min，铅浸出率达到91．14％。该法对铜、锌和铅都有很好的浸出效果。

高硅氧化铅锌矿加压酸浸中锌的浸出动力学

探讨了高硅氧化铅锌矿加压酸浸中锌的浸出反应动力学。考察了温度、硫酸浓度、搅拌速度、压力对锌浸出的影响。结果表明:氧化铅锌矿加压酸浸过程遵循"未反应核缩减"模型,浸出过程属于固体膜层扩散控制,表观反应级数为1.09,在试验选取的温度范围内,浸出的扩散活化能14.3kJ/mol。

复杂铜铅锌硫化矿浮选的研究

内蒙某铜铅锌硫化矿的铜铅锌品位低,矿物组成较复杂,并且铅锌矿物都存在不同程度的氧化.采用优先浮铅、浮铅的尾矿选锌的工艺,用SN-9和CD作方铅矿的捕收剂,38号黄药作锌矿物的捕收剂,在原矿品位为Pb 1.08%和Zn 2.43%时,获得品位41.8%、回收率60.96%的铅精矿和品位45.76%、回收率78.97%的锌精矿,铜主要富集在铅精矿中.

广西某低品位硫氧混合型铅锌矿选矿工艺

在工艺矿物学研究的基础上针对广西某大型低品位硫氧混合型铅锌矿进行了选矿工艺研究。结果表明,矿石中的方铅矿属于细粒嵌布,与闪锌矿、黄铁矿相互交代连生,且有部分氧化和泥化,采用优先浮铅—活化浮锌的工艺流程依次获得铅精矿、锌精矿。全流程闭路试验得到含铅52.13%、锌3.15%,铅回收率为61.36%的铅精矿和含锌51.60%,锌回收率为90.04%的锌精矿。

氧硫混合铅锌矿的选择性磨矿研究与实践

会泽选矿厂采用两段闭路磨矿流程,选矿产品中铅锌互含较高,选矿指标不理想。根据氧硫混合铅锌矿的抗破碎力学性能和磨机给矿的粒度特性,结合磨矿介质尺寸、初装方案、形状对铅锌矿选择性磨矿影响的实验室试验研究,确定合适的初装方案,进行工业应用研究。研究表明:在粗磨和粗精矿再磨的两段磨矿流程中采用铸铁段取代钢球,使整个磨矿流程实现了线接触破碎,并通过磨矿工艺的逐步调整,满足了氧硫混合铅锌矿选择性磨矿的要求,减轻了过粉碎粒级-0.025mm的含量。选矿指标好转,产品之间的互含减轻,锌精矿中的铅品位下降10%,硫精矿中的铅品位下降30%左右;尾矿品位下降显著,尾矿中的金属损失减少。

常见硫化物的氧化作用及其环境效应

自然或人为采矿活动暴露的硫化物矿物的氧化作用 ,常产生一定范围的次生地球化学异常和严重的环境污染。在黄铁矿、方铅矿、闪锌矿、毒砂等硫化物矿物氧化过程中 ,S、Pb、Cd、As等有害元素将被有效释放而进入水体 ,并通过大气 -水 -土壤 -植物

缅甸某铅锌银多金属氧硫混合矿选矿技术开发研究

对缅甸某铅锌银多金属氧硫混合矿进行了选矿流程方案试验,遴选出优先浮铅⁃活化选锌⁃硫化黄药法浮选回收氧化铅工艺方案,闭路试验可获得铅精矿铅品位52.25%、含银1732.52 g/t、回收率分别为65.96%和78.28%,锌精矿锌品位43.82%、含银209.56 g/t、回收率分别为79.15%和11.90%,氧化铅精矿铅品位35.62%、含银215.55 g/t、回收率分别为11.16%和2.42%。2种铅精矿综合铅品位48.94%、总回收率77.12%,含银1430.97 g/t、回收率80.70%。

园林绿化废弃物堆肥对铅、锌污染土壤上小白菜生理特性的影响

为探讨园林绿化废弃物堆肥(GWC)对重金属污染下小白菜(Brassica chinensis L.)生理特性的影响,采用盆栽试验,研究不同GWC施用量(质量分数分别为0、1%、2%、5%)对铅(500 mg·kg^-1)、锌(1000 mg·kg^-1)单一和复合污染下小白菜生物量、叶绿素含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性和游离脯氨酸含量的影响。结果表明:随着GWC施用量的增加,铅、锌单一和复合污染下小白菜生物量、叶绿素含量、游离脯氨酸含量呈上升趋势,MDA含量有不同程度的下降。施用GWC能提高铅、锌单一和复合污染下小白菜CAT活性。施用适当量的GWC能促进小白菜生长,改善小白菜生理特性,提高小白菜抵御铅、锌胁迫的能力。

某高泥型硫氧混合铅锌矿选矿技术研究及工业实践

针对云南兰坪地区某高泥型硫氧混合铅锌矿开展选矿技术研究。在工艺矿物学分析的基础上,结合了常规氧化锌选矿难点,确定了预先脱泥—泥质重选回收氧化锌—先硫后氧浮选回收铅锌的"重—浮"联合回收工艺。研究使用离心机有效地回收了泥质中的氧化锌矿物,氧化锌浮选采用新型组合捕收剂改善了氧化锌矿物分选效果,全套技术成功地应用于该矿山生产,取得了优异的工业生产指标。

选择性絮凝浮选法处理某低品位硫氧混合铅锌矿选矿试验研究

云南某特大型硫氧混合铅锌矿原矿因深度泥化,预先脱泥造成大量金属流失、直接硫化-胺法浮选很难富集,针对以上特性,在工艺矿物学分析的基础上在浮选过程中加入分散剂腐殖酸钠+LA处理硫化锌浮选尾矿矿浆,再加入高效的选择性絮凝剂KN絮凝细泥,絮凝沉降后的精矿再加入硫化钠及胺类捕收剂进行硫化-胺法浮选,使用该方法处理原矿含铅2.21%、含锌7.71%的硫氧混合铅锌矿可获得较优的选矿指标,其中氧化锌精矿品位达35.26%,硫化锌和氧化锌总回收率达81.26%,该指标优于国内同类型氧化铅锌矿山,为矿山下一步技术改造提供了夯实的科学依据。