The mineral industry is an opportunity-based challenging investment with high risk. Risks include geological uncertainties, technical inefficiency, commercial feasibility, political stability, and the will of regulating authorities. Investment decisions arise at exploration, development, and production with interrelated components of resource, risk, and revenue. Investment risk can be visualized through cash flow, net present value, internal rate of return, and sensitivity analysis resulting in profit or loss. Investors prefer early and bigger benefits. Sources of investment risks include scientific, technical, price fluctuation, and sociopolitical determination. Economic evaluation is assessed on technical, economic, and community needs. Information is collected during geological, feasibility, and economic studies with due diligence at that point of operation. Evaluation factors are gross in situ value, mining and milling losses, smelting and refining charges, transportation costs, capital and operating expenditure, revenue income, inflation, depreciation, depletion, amortization, royalties, taxes, and cash flow with examples of two scoping studies. A checklist for information collection norms for investment in new mineral projects is discussed.
Exploration case histories enrich our knowledge base for future mineral search. They help in conceptualizing the possibility of mineral occurrences in new matching environments. Topics include: ancient metal mining traditions at Zawar, India, the world's largest and richest zinc deposit at Broken Hill , Australia, the single largest porphyry copper-molybdenum deposit at Malanjkhand, India, routine drilling that discovered concealed Sindesar-Khurd Zn–Pb–Ag, India, geophysical success in locating concealed Neves Corvo orebody, Portugal, the world's largest platinum-chromium deposit at Bushveld, South Africa, the world's largest nickel-platinum deposit at Sudbury, Canada, the single largest Ni–Cu–PGE deposit at Jinchuan, China, geostatistical applications in borehole optimization at Rampura-Agucha, India, and environmental system management at Jhamarkotra rock phosphate mine, India. Mineral discovery trends can be analyzed for the country as well as from a global perspective to forecast and overview the future path of exploration. Each deposit has its own unique characteristics, and symbolizes a type. Each case history focuses on the application aspect of the book. Eleven case studies allow one to quickly apply exploration concepts to real-life scenarios in the field.
Geophysics works on the principles of physics to study Earth from core to surface. The process involves quantitative measurements of response or contrast in properties between rocks, structures, stratigraphy, and mineralization. Variations are either the position of objects or the function of time. Interpretation highlights the "signal" of mineral-related features under investigation or nongeological "noise." An anomaly is a significant departure from the normal pattern of background values and must be explained geologically, indicating possible occurrences of oil and mineral deposits. Geophysics covers a wide domain of applications, e.g., seismic, gravitational, magnetic, electrical, including resistivity, induced potential and self-potential, electromagnetic, radiometric, and borehole logging. Geophysics supplements a quick and cost-effective path to identify subsurface objects and prioritize drill targets. Borehole logging asserts ore continuity during feasibility and mining. Specialized instrument training, mathematical interpretation skill, capacity of depth penetration, and the experience of practicing professionals add significance to successful investigations. It optimizes exploration programs by maximizing the rate of ground coverage and minimizing expensive drilling needs. The techniques are time tested and proven for discovery of deep-seated mineral deposits all over the world.
Boundless imagination, ideas, concepts, models, and systematic exploration may end with the discovery of economic deposits. Exploration models are dynamic investigation techniques that cover all physical and chemical interrelated parameters. Models develop from observations of the past, data input of the present, and interpretation to make an experimental or prototype for future search. They foresee the unknown to achieve the targets. Exploration modeling follow the same principle under similar geological conditions with additional support from local effects. Exploration programs perceive various models like descriptive, conceptual, genetic, deposit/belt, predictive, statistical/geostatistical, orebody, grade/tonnage, and empirical types. The broad objectives and strategies are defined at the start to select one or more complementary models. The purpose is target selection, future investment decision, resource augmentation, sample optimization, economic evaluation, and midterm corrections under multidisciplinary functions. Geoscientists have to follow routine planning, integration, and interpretation with untiring effort to attain success. Models have to be tested for acceptability. Models work on dynamic and holistic approaches within their limitations.
Exploration geochemistry deals with the enrichment or depletion of certain trace elements having a genetic affinity to parent mineralization. The art of geochemistry is to identify “primary” or “secondary halos” formed by natural dispersion of indicator elements. Halos exist around the parent body or move distances by physical and chemical processes. Success depends initially on planning of the orientation survey to distinguish thresholds, background values, and anomalies. The parameters are host environment, dispersion characteristics, contamination, topography, sampling medium, optimum interval, depth, size fraction, analytical techniques, and anomaly enhancement. There are low-cost field analytical and expensive instruments. The most widely used unbiased techniques are preferred. Geochemical studies carry out the successive reduction of areas from regional, provincial, district, and local scales. An entire range of geochemical processes is focused on soils, weathering profile, isotope dating, rocks, stream sediments, groundwater, vegetation, lifeforms, vapor, and electrogeochemical, radiogenic isotope, heavy mineral, polymetallic polynodule, and hydrocarbon surveys. Geochemistry played a vital role in mineral exploration long before conceptualization and continues much beyond mine closure.
Mineral resources are in situ concentrations of minerals existing on or in Earth's crust that eventually become ore reserves, primary sources for economic extraction. Key functions are estimation of quantity (tonnage), quality (% and g/t of metal content), hydrocarbon estimation, classification scheme, and reporting codes for mineral, oil, and gas. The various time-tested traditional estimation procedures are based on complexity of mineralization, exploration techniques, sampling type, and adequacy. Methods are old style, triangular, square, rectangular, polygonal, isopach, isograde, cross-section, longitudinal-section, level plan, and inverse power of distance. Classification schemes and reporting codes have been evolved by different countries to propagate between exploration and mining companies, investors, and financial hubs through stock exchanges. Classification is based on increasing level of geological confidence, consideration of economic mining, metallurgy, marketing, legal, social, environmental, and governmental factors, industry best practices, competitiveness, acceptability, and internationality. The worldwide classification codes include US Geological Survey for ore and hydrocarbons, United Nations Framework, Joint Ore Reserve Committee, Canadian classification, and South African Code. The reporting of information code is credited by a reputed qualified person.
The uncertainties in determining the level of significance and confidence of traditional estimations are overcome by application of statistical and geostatistical procedures in mineral exploration and assessment. Statistics assume probability of various distributions. The equality between population and sample parameters are authenticated by null hypothesis, t , F , and chi-square test with level of significance. Correlation coefficient and analysis of variance between multivariable data are useful. Trend surface mapping provides generalized view of geological features. Statistical techniques estimate global average grade and confidence limit by normal, lognormal and probability plots.
Mineral deposits, in various forms and industrial uses, are economic and profitable as an investment. Principal ore minerals with formulae, % metal/element content, and major uses are listed. Understanding of deposit-type benefits to formulate an appropriate and effective exploration program from grassroots to mining is essential. Deposits are classified based on multiple criteria like geographic localization, depth of occurrence, host rock relation, structural control, nature of mineralization, morphology, genetic features, and contained metals. Deposit class is perceivable, comparable, and acceptable. All topics end with global examples. Mineral deposits are an integral part of host rocks formed at a definite time and space. Orebodies are concentrations of mineral(s) or metal(s) and are technoeconomically minable. Ore minerals have empathy to host rocks, associated elements, and deposit type. Adequate knowledge of favorable stratigraphy, structure, and host rock of the region is necessary to design an exploration program. Attention is focused on layered mafic–ultramafic rocks in the search for platinum-group elements. A proterozoic carbonate black schist environment is the preferred target for sedimentary exhalative sulfide ore. Mineral sectors work on standard industrial specifications for saleable market-finished commodities.
Mineral discovery was traditionally based on tangible surface studies. Application of RS by capturing airborne digital images and electromagnetic energy (EME) contributed several dimensions to modern exploration.
Case histories and applications of exploration, mining, processing, estimation, environment, sustainability and discovery trend enrich knowledge base that helps conceptualizing possibility of mineral occurrences in new matching environments. Topics include age-old ancient metal mining tradition, exploration of World’s largest and richest deposits, locating concealed orebody through geophysical success, geostatistical applications in estimation, QC and QA, geological model-based concepts, environment management practices and finally mineral discovery trend. Each deposit is unique in own characteristic and symbolizes a type. Each case history focuses on application aspect of the book. Ten case studies allow you to quickly apply exploration concepts to real-life scenarios in the field.
Mining is excavation and recovery of ore and associated waste rocks from Earth's crust. The principle of mining is not to maximize ore production but to aim at zero waste generation and long-term sustainable development of nonrenewable wasting assets. The technology relies on rock competency, distance to surface, size, and orebody attributes, and is broadly grouped into surface and underground and soft and hard rock operations. Stoping is characterized by scale of mechanization, production capacity, productivity, postmining support, and cost per tonne of ore. Methods include open pit, underground soft bedded, and hard massive orebody. Mine access suites the technology during initial development. Production capacity and productivity increase with size of ore reserves, innovative cost-effective mining methods, and advanced mechanization. The procedure includes development, large diameter drilling, blasting, sizing, and transportation to in-house or third-party beneficiation plants. A standard-quality explosive improves the powder factor. Rock mechanic studies predict the best support system. Better mine ventilation improves the working conditions. Mine closure is an integral part within the legislative framework. A combination of in-house and commercial software provides the best possible design, execution, and product mix.
Geological exploration for natural resources is expensive with high risk. However, it opens new challenges and opportunities. Governments and multinational companies are key players. Geological exploration follows a sequence of multidisciplinary activities: reconnaissance, discovery, prospecting, and economic mining. The exploration concept looks for a package of unique stratigraphic age, promising favorable rocks, and type structure to host certain groups of minerals. Mineral deposits portray a surface signature similar to mineral exposed to a surface, weathering effects (laterite, gossan), remnants of ancient mining, shear zone, and lineaments that can be identified during a field survey. These features guide exploration and may end with new discoveries. A good quality, precise, surface geological map with various scales plays a significant role in producing an exploration program. Exploration continues at regional, district, belt, and deposit levels with prerequisite activities to achieve specific objectives. Stratigraphic correlation compares and establishes litho formation to host economic minerals for future searches. Exploration exclusively for coal-lignite, coalbed methane, and oil and gas needs carboniferous and younger sedimentary formation and complementary structures having sufficient plants and algae to form fossil fuels. World reserves and production are highlighted.
Metal content and surface properties vary widely between minerals. End-users look for the highest purity of minerals. Run-of-mine ore is beneficiated through particle size reduction, liberation, separation, and concentration using physical and surface chemical properties. Ore is crushed, grinded, and classified. Valuable minerals are concentrated by leaching and sorting with light reflectance, gamma radiation, and X-ray luminescence. Gravity concentration is possible by panning, jigging, spiraling, shaking table, and multigravity and dense medium separation. Magnetic and electrostatic properties aid in concentration. The majority of ore (Cu, Zn, Pb, platinum-group elements, etc.) is best suited to froth flotation, which includes conditioning of fine liberated particles and reagents like collectors, depressors, regulators, and frothers. Slurry passes through rougher-scavenger cells and concentrates. Concentrates are cleaned by washing, sedimentation, and dewatering. Rejects are disposed to tailing ponds or used for the void-filling stabilization of underground stopes. Column flotation improves quality and recovery. Plant performance is judged by metallurgical accounting, metal balancing, operating cost, quantity, purity, recovery, and valuation. Extractive pyrometallurgy, hydrometallurgy, and refining processes recover the purest metals from concentrates.
In order to investigate the groundwater environment in Tianjin City. Nine heavy metal elements in 93 groundwater specimens were detected. Multiple statistical analysis and comprehensive evaluation modus were applied to explore the distribution as well as pollution of heavy metal elements. The average values of heavy metal contents were Mn > Ba > Zn > As > Se > Cu > Ni > Pb > Cd. The Mn, As and Ba outstriped the national level II standard. Besides other heavy metals were conform to the national level I standard. The groundwater was polluted by Mn, Se, As, Ba. Ni, Cu, and Zn in the groundwater mainly came from industrial, agricultural, and traffic pollution. Pb and Cd influenced by natural sources. Ba, As, Mn, and Se impacted by human activities and natural factors simultaneously. The carcinogenic risk of groundwater was mainly affected by As, with the main influencing pathway being the drinking route. The lifetime risk of cancer in both adults and children was greater than 1 × 10−4 a−1. The non-carcinogenic risk of groundwater was affected by As and Se. The non-carcinogenic risk of drinking was greater than skin contact. Comparing children, the risk in adults is higher. The non-carcinogenic risk values of both children and adults exposed through two pathways are higher than the safety limit of 1.
三苏木西银多金属矿床所在区域地质及找矿工作程度较低,为了解研究区成矿地质条件和找矿前景,本文基于研究区地表地质特征,通过开展土壤地球化学测量和激电测量,圈定元素地球化学异常和激电异常;通过对重点异常进行查证,分析物化探异常特征与金属矿化、断裂构造、蚀变带的对应关系,进而研究区内构造、岩体与成矿的内在联系,对探讨研究区成矿控矿要素、主要矿化元素组合、找矿前景与找矿方向具有一定意义.
以鄂尔多斯盆地合水地区长6超低渗透砂岩储层为例,综合应用储层敏感性、扫描电镜、X射线衍射等实验技术方法,系统研究了储层敏感性类型及损害程度,并深入地探讨了黏土矿物对于长6储层敏感性的影响与控制作用.结果表明:①长6油层的储层敏感性整体表现为中等偏强水敏性和速敏性、弱酸敏性、强盐敏性以及中等偏弱碱敏性的五敏特征;②储层黏土矿物主要有高岭石、伊利石、绿泥石以及伊蒙混层等4种类型,且以伊利石含量最高;③储层敏感性及其程度明显受控于黏土矿物类型及其含量,并且具有黏土矿物含量越高、储层敏感性越强的特点.本研究成果将为合水地区长6油层注水开发过程中有效保护储层以及提高采收率提供重要的参考依据.
钼是一种重要的战略金属,也是中国的优势矿产品资源,关系到我国军事、政治、经济安全.近年钼的价格大起大落,行业利润波动较大,企业避险需求强.然而,在可以提供有效风险管理的国内期货市场上,目前还没有钼期货.本文从产业需求出发,对钼产业进行了研究,认为钼精矿和钼铁具有可标准化、市场规模适中、储运方便、市场化程度高等特征,适应开展期货交易.上市钼期货,有利于为企业提供风险管理工具,也有利于中国掌握钼的定价话语权.
