Ore classification
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Ore classification Ore is natural rock or sediment that contains one or more valuable minerals concentrated above background levels, typically containing metals, that can be mined, treated and sold at a profit. The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore. A complex ore is one containing more than one valuable mineral. Minerals of interest are generally oxides, sulfides, silicates, or native metals such as copper or gold. Ore bodies are formed by a variety of geological processes generally referred to as ore genesis, and can be classified based on their deposit type. Ore is extracted from the earth through mining and treated or refined, often via smelting, to extract the valuable metals or minerals. Some ores, depending on their composition, may pose threats to health or surrounding ecosystems. In most cases, an ore does not consist entirely of a single ore mineral but it is mixed with other valuable minerals and with unwanted or valueless rocks and minerals. The part of an ore that is not economically desirable and that can not be avoided in mining is known as gangue. The valuable ore minerals are separated from the gangue minerals by froth flotation, gravity concentration, electric or magnetic methods, and other operations known collectively as mineral processing or ore dressing. Mineral processing consists of first liberation, to free the ore from the gangue, and concentration to separate the desired mineral(s) from it. Once processed, the gangue is known as tailings, which are useless but potentially harmful materials produced in great quantity, especially from lower grade deposits. An ore deposit is an economically significant accumulation of minerals within a host rock. This is distinct from a mineral resource in that it is a mineral deposit occurring in high enough concentration to be economically viable. An ore deposit is one occurrence of a particular ore type. Most ore deposits are named according to their location, or after a discoverer (e.g. the Kambalda nickel shoots are named after drillers), or after some whimsy, a historical figure, a prominent person, a city or town from which the owner came, something from mythology (such as the name of a god or goddess) or the code name of the resource company which found it (e.g. MKD-5 was the in-house name for the Mount Keith nickel sulphide Different kinds of ores are found in nature. The four primary types of ores are halide ores, carbonate ores, sulphide ores, and oxide ores. Ore deposits are not distributed uniformly across the globe. Vast tracts of land are devoid of viable deposits while others constitute what are known as ‘metallogenic provinces’—regions containing an unusually high concentration of deposits of one or several types. Notable examples include the numerous copper deposits in the southwestern United States, the clusters of lead-zinc deposits in northeastern Australia, and the tin deposits of SE Asia. For both geological and economic reasons, it is important to have some knowledge of this distribution. From a geological point of view, the distribution provides important clues to the ore-forming process; from an economic point of view, the irregular distribution strongly influences metal prices and global trade, and is a factor that influences many of the alliances and conflicts that govern relationships between countries around the world. In plate tectonic classifications of ore deposits, the emphasis is quite naturally on the tectonic setting in which the deposit occurs. But many deposits develop in sedimentary settings or as a result of superficial weathering; in such cases geo- morphology, surface relief, and modern or past climate exert an additional important influence of the localization of the deposits. All these factors are dis- cussed briefly in the foll. Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis. The following is a general categorization of the main ore deposit types: Magmatic deposits Magmatic deposits are ones who originate directly from magma Granitic pegmatite composed of plagioclase and K-feldspar, large hornblende crystal present. Scale bar is 5.0 cm Pegmatites are very coarse grained, igneous rocks. They crystallize slowly at great depth beneath the surface, leading to their very large crystal sizes. Most are of granitic composition. They are a large source of industrial minerals such as quartz, feldspar, spodumene, petalite, and rare lithophile elements. Carbonatites are an igneous rock whose volume is made up of over 50% carbonate minerals. They are produced from mantle derived magmas, typically at continental rift zones. They contain more rare earth elements than any other igneous rock, and as such are a major source of light rare earth elements. Magmatic Sulfide Deposits form from mantle melts which rise upwards, and gain sulfur through interaction with the crust. This causes the sulfide minerals present to be immiscible, precipitating out when the melt crystallizes. Magmatic sulfide deposits can be subdivided into two groups by their dominant ore element: Ni-Cu, found in komatiites, anorthosite complexes, and flood basalts. This also includes the Sudbury Nickle Basin, the only known astrobleme source of such ore. Platinum Group Elements (PGE) from large mafic intrusions and tholeiitic rock. Stratiform Chromites are strongly linked to PGE magmatic sulfide deposits. These highly mafic intrusions are a source of chromite, the only chromium ore. They are so named due to their strata-like shape and formation via layered magmatic injection into the host rock. Chromium is usually located within the bottom of the intrusion. They are typically found within intrusions in continental cratons, the most famous example being the Bushveld Complex in South Africa. Podiform Chromitites are found in ultramafic oceanic rocks resulting from complex magma mixing. They are hosted in serpentine and dunite rich layers and are another source of chromite. Kimberlites are a primary source for diamonds. They are originate from depths of 150 km in the mantle and are mostly composed of crustal xenocrysts, high amounts of magnesium, other trace elements, gases, and in some cases diamond. Metamorphic deposits These are ore deposits which form as a direct result of metamorphism. Skarns occur in numerous geologic settings worldwide. They are silicates derived from the recrystallization of carbonates like limestone through contact or regional metamorphism, or fluid related metasomatic events. Not all are economic, but those that are, are classified depending on the dominant element such as Ca, Fe, Mg, or Mn among many others. They are one of the most diverse and abundant mineral deposits. As such they are classified solely by their common mineralogy, mainly garnets and pyroxenes. Greisens, like skarns, are a metamorphosed silicate, quartz-mica mineral deposit. Formed from a granitic protolith due to alteration by intruding magmas, they are large ore sources of tin and tungsten in the form of wolframite, cassiterite, stannite and scheelite Porphyry copper deposits These are the leading source of copper ore. Porphyry copper deposits form along convergent boundaries and are thought to originate from the partial melting of subducted oceanic plates and subsequent concentration of Cu, driven by oxidation. These are large, round, disseminated deposits containing on average 0.8% copper by weight. Hydrothermal A cross-section of a typical volcanogenic massive sulfide (VMS) ore deposit Hydrothermal deposits are a large source of ore. They form as a result of the precipitation of dissolved ore constituents out of fluids. Mississippi Valley-Type (MVT) deposits precipitate from relatively cool, basal brinal fluids within carbonate strata. These are sources of lead and zinc sulphide ore. Sediment-Hosted Stratiform Copper Deposits (SSC) form when copper sulphides precipitate out of brinal fluids into sedimentary basins near the equator. These are the second most common source of copper ore after porphyry copper deposits, supplying 20% of the worlds copper in addition to silver and cobalt. Volcanogenic massive sulphide (VMS) deposits form on the seafloor from precipitation of metal rich solutions, typically associated with hydrothermal activity. They take the general form of a large sulphide rich mound above disseminated sulphides and viens. VMS deposits are a major source of zinc (Zn), copper (Cu), lead (Pb), silver (Ag]], and gold (Au). are a copper sulphide ore which form in the same manor as VMS from metal rich brine, but are hosted within sedimentary rocks and are not directly related to volcanism. Orogenic gold deposits are a bulk source for gold, with 75% of gold production originating from orogenic gold deposits. Formation occurs during late stage mountain building (see orogeny) where metamorphism forces gold containing fluids into joints and fractures where they precipitate. These tend to be strongly correlated with quartz veins. Epithermal vein deposits form in the shallow crust from concentration of metal bearing fluids into veins and stockworks where conditions favour precipitation. These volcanic related deposits are a source of gold and silver ore, the primary precipitants. Sedimentary deposits Magnified view of banded iron formation specimen from Upper Michigan. Scale bar is 5.0 mm. Laterites form from the weathering of highly mafic rock near the equator. They can form in as little as one million years and are a source of iron (Fe), manganese (Mn), and aluminum (Al). They may also be a source of nickel and cobalt when the parent rock is enriched in these elements. Banded iron formations (BIFs) are the highest concentration of any single metal available. They are composed of chert beds alternating between high and low iron concentrations. Their deposition occurred early in Earth's history when the atmospheric composition was significantly different than today. Iron rich water is thought to have upwelled where it oxidized to Fe (III) in the presence of early photosynthtic plankton producing oxygen. This iron then precipitated out and deposited on the ocean floor. The banding is thought to be a result of changing plankton population. Sediment Hosted Copper forms from the precipitation of a copper rich oxidized brine into sedimentary rocks. These are a source of copper primarily in the form of copper-sulfide minerals. Placer deposits are the result of weathering, transport, and subsequent concentration of a valuable mineral via water or wind. They are typically sources of gold (Au), platinum group elements (PGE), sulfide minerals, tin (Sn), tungsten (W), and rare-earth elements (REEs). A placer deposit is considered alluvial if formed via river, colluvial if by gravity, and eluvial when close to their parent rock. The extraction of ore deposits generally follows these steps. Progression from stages 1–3 will see a continuous disqualification of potential ore bodies as more information is obtained on their viability: Prospecting to find where an ore is located. The prospecting stage generally involves mapping, geophysical survey techniques (aerial and/or ground-based surveys), geochemical sampling, and preliminary drilling. After a deposit is discovered, exploration is conducted to define its extent and value via further mapping and sampling techniques such as targeted diamond drilling to intersect the potential ore body. This exploration stage determines ore grade, tonnage, and if the deposit is a viable economic resource. A feasibility study then considers the theoretical implications of the potential mining operation in order to determine if it should move ahead with development. This includes evaluating the economically recoverable portion of the deposit, marketability and payability of the ore concentrates, engineering, milling and infrastructure costs, finance and equity requirements, potential environmental impacts, political implications, and a cradle to grave analysis from the initial excavation all the way through to reclamation. Multiple experts from differing fields must then approve the study before the project can move on to the next stage. Depending on the size of the project, a pre-feasibility study is sometimes first performed to decide preliminary potential and if a much costlier full feasibility study is even warranted. Development begins once an ore body has been confirmed economically viable, and involves steps to prepare for its extraction such as building of a mine plant and equipment. Production can then begin, and is the operation of the mine in an active sense. The time a mine is active is dependent on its remaining reserves and profitability. The extraction method used is entirely dependent on the deposit type, geometry, and surrounding geology. Methods can be generally categorized into surface mining such as open pit or strip mining, and underground mining such as block caving, cut and fill, and stoping. Reclamation, once the mine is no longer operational, makes the land where a mine had been suitable for future use. With rates of ore discovery in a steady decline since the mid 20th century, it is thought that most surface level, easily accessible sources have been exhausted. This means progressively lower grade deposits must be turned to, and new methods of extraction must be developed. Metallurgy began with the direct working of native metals such as gold, lead and copper. Placer deposits, for example, would have been the first source of native gold. The first exploited ores were copper oxides such as malachite and azurite, over 7000 years ago at Çatalhöyük . These were the easiest to work, with relatively limited mining and basic requirements for smelting. It is believed they were once much more abundant on the surface than today. After this, copper sulphides would have been turned to as oxide resources depleted and the Bronze Age progressed. Lead production from galena smelting may have been occurring at this time as well. The smelting of arsenic-copper sulphides would have produced the first bronze alloys. The majority of bronze creation however required tin, and thus the exploitation of cassiterite, the main tin source, began. Some 3000 years ago, the smelting of iron ores began in Mesopotamia. Iron oxide is quite abundant on the surface and forms from a variety of processes. Until the 18th century gold, copper, lead, iron, silver, tin, arsenic and mercury were the only metals mined and used. In recent decades, Rare Earth Elements have been increasingly exploited for various high-tech applications. This has led to an ever-growing search for REE ore and novel ways of extracting said elements. Ores (metals) are traded internationally and comprise a sizeable portion of international trade in raw materials both in value and volume. This is because the worldwide distribution of ores is unequal and dislocated from locations of peak demand and from smelting infrastructure. Most base metals (copper, lead, zinc, nickel) are traded internationally on the London Metal Exchange, with smaller stockpiles and metals exchanges monitored by the COMEX and NYMEX exchanges in the United States and the Shanghai Futures Exchange in China. The global Chromium market is currently dominated by the United States and China. Iron ore is traded between customer and producer, though various benchmark prices are set quarterly between the major mining conglomerates and the major consumers, and this sets the stage for smaller participants. Other, lesser, commodities do not have international clearing houses and benchmark prices, with most prices negotiated between suppliers and customers one-on-one. This generally makes determining the price of ores of this nature opaque and difficult. Such metals include lithium, niobium-tantalum, bismuth, antimony and rare earths. Most of these commodities are also dominated by one or two major suppliers with >60% of the world's reserves. China is currently leading in world production of Rare Earth Elements. The World Bank reports that China was the top importer of ores and metals in 2005 followed by the US and Japan. Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined. Ore-genesis theories generally involve three components: source, transport or conduit, and trap. (This also applies to the petroleum industry: petroleum geologists originated this analysis.) Source is required because metal must come from somewhere, and be liberated by some process. Transport is required first to move the metal-bearing fluids or solid minerals into their current position, and refers to the act of physically moving the metal, as well as to chemical or physical phenomena which encourage movement. Trapping is required to concentrate the metal via some physical, chemical, or geological mechanism into a concentration which forms mineable ore. The biggest deposits form when the source is large, the transport mechanism is efficient, and the trap is active and ready at the right time. metallogeny where various thiosulfate, chloride, and other gold-carrying chemical complexes (notably tellurium-chloride/sulfate or antimony-chloride/sulfate). The majority of metal deposits formed by hydrothermal processes include sulfide minerals, indicating sulfur is an important metal-carrying complex. Sulfide deposition: Sulfide deposition within the trap zone occurs when metal-carrying sulfate, sulfide, or other complexes become chemically unstable due to one or more of the following processes; falling temperature, which renders the complex unstable or metal insoluble loss of pressure, which has the same effect reaction with chemically reactive wall rocks, usually of reduced oxidation state, such as iron-bearing rocks, mafic or ultramafic rocks, or carbonate rocks degassing of the hydrothermal fluid into a gas and water system, or boiling, which alters the metal carrying capacity of the solution and even destroys metal-carrying chemical complexes Metal can also precipitate when temperature and pressure or oxidation state favour different ionic complexes in the water, for instance the change from sulfide to sulfate, oxygen fugacity, exchange of metals between sulfide and chloride complexes, et cetera. Metamorphic processes Ore deposits formed by lateral secretion are formed by metamorphic reactions during shearing, which liberate mineral constituents such as quartz, sulfides, gold, carbonates, and oxides from deforming rocks, and focus these constituents into zones of reduced pressure or dilation such as faults. This may occur without much hydrothermal fluid flow, and this is typical of podiform chromite deposits. Metamorphic processes also control many physical processes which form the source of hydrothermal fluids, outlined above. Sedimentary or surficial processes (exogenous) Surficial processes are the physical and chemical phenomena which cause concentration of ore material within the regolith, generally by the action of the environment. This includes placer deposits, laterite deposits, and residual or eluvial deposits. Superficial deposits processes of ore formation include; Erosion of non-ore material. Deposition by sedimentary processes, including winnowing, density separation (e.g.; gold placers). Weathering via oxidation or chemical attack of a rock, either liberating rock fragments or creating chemically deposited clays, laterites, or supergene enrichment. Deposition in low-energy environments in beach environments. Sedimentary Exhalative Deposits, formed on the sea floor from metal-bearing brines. Classification of hydrothermal ore deposits is also achieved by classifying according to the temperature of formation, which roughly also correlates with particular mineralising fluids, mineral associations and structural styles. This scheme, proposed by Waldemar Lindgren (1933) classified hydrothermal deposits as follows: Hypothermal — mineral ore deposits formed at great depth under conditions of high temperature. Mesothermal — mineral ore deposits formed at moderate temperature and pressure, in and along fissures or other openings in rocks, by deposition at intermediate depths, from hydrothermal fluids. Epithermal — mineral ore deposits formed at low temperatures (50–200 °C) near the Earth's surface (<1500 m), that fill veins, breccias, and stockworks. Telethermal — mineral ore deposits formed at shallow depth and relatively low temperatures, with little or no wall-rock alteration, presumably far from the source of hydrothermal solutions. Ore deposits are usually classified by ore formation processes and geological setting. For example, sedimentary exhalative deposits (SEDEX), are a class of ore deposit formed on the sea floor (sedimentary) by exhalation of brines into seawater (exhalative), causing chemical precipitation of ore minerals when the brine cools, mixes with sea water, and loses its metal carrying capacity. Ore deposits rarely fit neatly into the categories in which geologists wish to place them. Many may be formed by one or more of the basic genesis processes above, creating ambiguous classifications and much argument and conjecture. Often ore deposits are classified after examples of their type, for instance Broken Hill type lead-zinc-silver deposits or Carlin–type gold deposits. As they require the conjunction of specific environmental conditions to form, particular mineral deposit types tend to occupy specific geodynamic niches, therefore, this page has been organised by metal commodity. It is also possible to organise theories the other way, namely according to geological criteria of formation. Often ores of the same metal can be formed by multiple processes, and this is described here under each metal or metal complex. Iron Iron ores are overwhelmingly derived from ancient sediments known as banded iron formations (BIFs). These sediments are composed of iron oxide minerals deposited on the sea floor. Particular environmental conditions are needed to transport enough iron in sea water to form these deposits, such as acidic and oxygen-poor atmospheres within the Proterozoic Era. Often, more recent weathering is required to convert the usual magnetite minerals into more easily processed hematite. Some iron deposits within the Pilbara of Western Australia are placer deposits, formed by accumulation of hematite gravels called pisolites which form channel-iron deposits. These are preferred because they are cheap to mine. The gold is transported up faults by hydrothermal waters and deposited when the water cools too much to retain gold in solution. Intrusive related gold (Lang & Baker, 2001) is generally hosted in granites, porphyry, or rarely dikes. Intrusive related gold usually also contains copper, and is often associated with tin and tungsten, and rarely molybdenum, antimony, and uranium. Intrusive-related gold deposits rely on gold existing in the fluids associated with the magma (White, 2001), and the inevitable discharge of these hydrothermal fluids into the wall-rocks (Lowenstern, 2001). Skarn deposits are another manifestation of intrusive-related deposits. Placer deposits are sourced from pre-existing gold deposits and are secondary deposits. Placer deposits are formed by alluvial processes within rivers and streams, and on beaches. Placer gold deposits form via gravity, with the density of gold causing it to sink into trap sites within the river bed, or where water velocity drops, such as bends in rivers and behind boulders. Often placer deposits are found within sedimentary rocks and can be billions of years old, for instance the Witwatersrand deposits in South Africa. Sedimentary placer deposits are known as 'leads' or 'deep leads'. Placer deposits are often worked by fossicking, and panning for gold is a popular pastime. Laterite gold deposits are formed from pre-existing gold deposits (including some placer deposits) during prolonged weathering of the bedrock. Gold is deposited within iron oxides in the weathered rock or regolith, and may be further enriched by reworking by erosion. Some laterite deposits are formed by wind erosion of the bedrock leaving a residuum of native gold metal at surface. A bacterium, Cupriavidus metallidurans plays a vital role in the formation of gold nuggets, by precipitating metallic gold from a solution of gold (III) tetrachloride, a compound highly toxic to most other microorganisms. Similarly, Delftia acidovorans can form gold nuggets. The gold is transported up faults by hydrothermal waters and deposited when the water cools too much to retain gold in solution. Intrusive related gold (Lang & Baker, 2001) is generally hosted in granites, porphyry, or rarely dikes. Intrusive related gold usually also contains copper, and is often associated with tin and tungsten, and rarely molybdenum, antimony, and uranium. Intrusive-related gold deposits rely on gold existing in the fluids associated with the magma (White, 2001), and the inevitable discharge of these hydrothermal fluids into the wall-rocks (Lowenstern, 2001). Skarn deposits are another manifestation of intrusive-related deposits. Placer deposits are sourced from pre-existing gold deposits and are secondary deposits. Placer deposits are formed by alluvial processes within rivers and streams, and on beaches. Placer gold deposits form via gravity, with the density of gold causing it to sink into trap sites within the river bed, or where water velocity drops, such as bends in rivers and behind boulders. Often placer deposits are found within sedimentary rocks and can be billions of years old, for instance the Witwatersrand deposits in South Africa. Sedimentary placer deposits are known as 'leads' or 'deep leads'. Placer deposits are often worked by fossicking, and panning for gold is a popular pastime. Laterite gold deposits are formed from pre-existing gold deposits (including some placer deposits) during prolonged weathering of the bedrock. Gold is deposited within iron oxides in the weathered rock or regolith, and may be further enriched by reworking by erosion. Some laterite deposits are formed by wind erosion of the bedrock leaving a residuum of native gold metal at surface. Ore genesis processes Ore genesis may be divided into several categories, based on the processes involved. These categories are: internal processes, hydrothermal processes, metamorphic processes, and surficial processes Internal processes: These are the physical and chemical processes that take place within magmas (molten rock beneath the Earth's surface) and lava flows (molten rock ejected by volcanic activity). Hydrothermal processes: These are the physical and chemical phenomena and reactions that occur during the movement of hydrothermal (hot-water) solutions within the crust. Metamorphic processes: Metamorphic (rock-transforming) reactions occur during geological shearing. These processes may liberate minerals from deforming rocks, focusing them into zones of reduced pressure or dilation such as geological faults. Metamorphic processes also control many physical processes that are the source of hydrothermal fluids. Surficial processes: These are the physical and chemical processes that occur on the Earth's surface, generally by the action of the environment. Examples of these processes are erosion and sedimentation. They concentrate ore material within the regolith (loose material covering solid rock). Iron
In addition, weathering during the Tertiary or Eocene periods converted the usual magnetite minerals into hematite, which is more easily processed. Some iron deposits in the Pilbara of West Australia are placer deposits, formed by the accumulation of hematite gravels called pisolites. They are less expensive to mine. Titanium Titanium ore is formed as placer deposits (mineral sands, noted below) or within ultramafic layered intrusions. In the latter case, titanium takes the form of layers of ilmenite, a titanium oxide mineral, through the process of crystallization as the intrusion cools. These layers can be considerably heavy and long, and this type of ore is known as "hard rock titanium." In addition, the ore may contain vanadium as a second metal within the ilmenite. Application (n) / ˌæp lɪˈkeɪ ʃən / – hujjat, ariza Alteration (n) /ˌɔːltəˈreɪʃn/ – o’zgarish, o’zgartirish Replacement (n) /rɪˈpleɪsmənt/ – almashtirish Classification (n) /ˌklæsɪfɪˈkeɪʃn/ – turlash, sinflarga ajratish Concentration (n) /ˌkɒnsnˈtreɪʃn/ – fikrni bir joyga jamlash Precipitation (n) /prɪˌsɪpɪˈteɪʃn/ – yog’ingarchilik Formation (n) /fɔːˈmeɪʃn/ – tashkil toppish Composition (n) /ˌkɒmpəˈzɪʃn/ – qisim, tarkib Qualification (n) /ˌkwɒlɪfɪˈkeɪʃn – mutaxassislik Extraction (n) /ɪkˈstrækʃn/ – ajratib olish Exploration (n) /ˌekspləˈreɪʃn/ – tadqiqot Excavation (n) /ˌekskəˈveɪʃn/ – qazilma ishlari Exploitation (n) /ˌeksplɔɪˈteɪʃn/ – foydalanish, ishlatish Operation (n) /ˌɒpəˈreɪʃn/ – jarrohlik, ish Requirement (n) /rɪˈkwaɪəmənt/ – talab, ehtiyoj Solve (v) /sɒlv/ – hal etmoq, hal qilmoq Originate (v) /əˈrɪdʒɪneɪt/ – keltirib chiqarmoq Occur (v) /əˈkɜː(r)/ – sodir bo’lmoq Obtain (v) /əbˈteɪn/ – bilim ,tajriba olmoq Relate (v) /rɪˈleɪt/ – ulanmoq, bog’liq bo’lmoq Enrich (v) /ɪnˈrɪtʃ/ – boyitmoq, boyimoq Evaluate (v) /ɪˈvæljueɪt/ - baholamoq Target (v) /ˈtɑːɡɪt/ – nishonga olmoq Confirm (v) /kənˈfɜːm/ – tasdiqlamoq Surround (v) /səˈraʊnd/ – qamrab olmoq Believe (v) /bɪˈliːv/ – ishonmoq Trade (v) /treɪd/ – savdo – sotiq qilmoq Depend (v) /dɪˈpend/ – bog’liq bo’lmoq Involve (v) /ɪnˈvɒlv/ – taqozo qilmoq Liberate (v) /ˈlɪbəreɪt/ – ozod qilmoq Chemical (adj) /ˈkemɪkl/ – kimyoviy Ready (adj) /ˈredi/ – tayyor , shay Important (adj) /ɪmˈpɔːtnt/ – muhim,zarur Structural (adj) /ˈstrʌktʃ(ə)r(ə)l/ – tuzilish jihatdan Specific (adj) /spəˈsɪfɪk/ – aniq, oydin Environmental (adj) /ɪnˌvaɪrənˈmentl/ – atrof – muhit Fractional (adj) /ˈfrækʃənl/ – juda kichik, ahamiyatsiz Abundant (adj) /əˈbʌnd(ə)nt/ – mo’l, serob Natural (adj) /ˈnætʃrəl/ – tabiiy Valuable (adj) /ˈvæljuəbl/ – ahamiyatli Download 31.17 Kb. Do'stlaringiz bilan baham: 
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