Primary Tin Research Articles

A New Source of Primary Tin Ore in the Indus Civilization

(1999). A New Source of Primary Tin Ore in the Indus Civilization. South Asian Studies: Vol. 15, No. 1, pp. 115-118.

Use of Landsat thematic Mapper imagery as mineral prospecting tool in the tin province of Goias, Brazil

Abstract The Tin Province of Goias, in central Brazil, includes several granitoids with greisenized‐albitized facies, which occupy the apical parts of the massifs. Stanniferous mineralizations (cassiterite) frequently occur associated with these metasomatkally altered facies. Areas of altered rocks bear open grasslands in contrast to the savanna‐type vegetation cover composed of small trees, shrubs and herbaceous plants occurring everywhere over the granitoids. Landsat Thematic Mapper ratio images (TM4/TM3) of the rainy season were used to delineate these target areas within the granitoids. Follow‐up field checking confirmed the occurrence of metasomatic rocks with cassiterite in most of the delineated areas. Thus, future prospecting work for primary tin deposits in the granitoids of the region can be largely facilitated by the use of this procedure.

Evolutionary trends of gold and tin deposits

The time distribution of the most important goldbearing conglomerates (Fig. 1) and the most important primary gold deposits (Fig. 2) reveals a major gold hiatus - a gap in gold mineralization between 1800 m.y. and 700-600 m.y. Unlike gold, the biggest concentration of which occurred in the Precambrian, the greatest concentration of tin took place in the Phanerozoic. Periodicity in the orogenic processes and granitization produced a certain time and space pattern of the primary gold and tin deposition. The origin of the space and time separation of gold and tin lies probably in the early inhomogeneities of the mantle and in the formation of the granitic parts of the primitive crust.

Origin of topaz-bearing and related peraluminous granites of the Late Devonian Davis Lake pluton, Nova Scotia, Canada: crystal versus fluid fractionation

The Davis Lake pluton, in the Late Devonian South Mountain Batholith in southwestern Nova Scotia (Canada), is composed of peraluminous leucomonzogranites and subordinate topaz-bearing leucogranites that host greisens and a primary tin deposit. The concentrations of incompatible trace elements (e.g., Rb, Li, U, F, Ta and Sn) and element (e.g., K Rb , Nb Ta and La Sm ) and isotopic ratios (e.g., 206 Pb 204 Pb and 87 Sr 86 Sr display a spatial zonation. The granitic rocks were generated by extensive fractional crystallization of major phases (feldspars and biotite) and accessory minerals (monazite, apatite and zircon) in a compositionally zoned magma chamber. Fractional crystallization of the evolving F-rich peraluminous granitic magma was accompanied, particularly in later stages, by fluid fractionation involving fluorine complexing. Fluid fractionation was a major differentiation process during the terminal stages of the pluton's evolution. It played an important role in the genesis of the evolved rocks which are characterized by low K Rb (24–150), Nb Ta (1–6), La Sm (1.5–4) and Eu Eu ∗ (0.01–0.3) ratios. These ratios as well as the enhanced concentrations of Li, Rb, U, Ta and Sn in these rocks correlate with F. Fluorine-rich fluids modified the Rb Sr and U Pb ratios which produced the distinct variations of 87 Sr 86 Sr and 206 Pb 204 Pb isotopic ratios. The parent magma was formed by dehydration melting of lower-crustal metasedimentary rocks. The melting was related to crustal thickening in association with terrane and collision along the eastern margin of the Appalachians.

Tin mineralization in the Archean Sinceni rare element pegmatite field, Kaapvaal Craton, Swaziland

The Sinceni pegmatite field constitutes a large group of 3.0 Ga granitic pegmatites in the exocontact of the Sinceni pluton in south-central Swaziland. Field relations, age dating, and geochemical evidence indicate a genetic relationship between the pegmatites and the Sinceni pluton. The Sinceni pegmatites are moderately fractionated granitic pegmatites belonging to the beryl type of the rare element class. The pegmatite field is compositionally zoned, with the highest fractionation and strongest mineralization in a restricted area referred to as Sinceni West. Only the alluvial and eluvial tin concentrations are of economic interest, and the largest of these is the Sinceni West deposit. Primary tin mineralization at the Sinceni West deposit consists of cassiterite in late-stage pegmatite units of sugary albite, associated with mica-tourmaline metasomatic selvages in the host rock. The albitic units are interpreted as the products of late residual melt, and the metasomatic selvages reflect fluid exsolution from the melt at the latest stage of pegmatite consolidation. Several factors contributed to the development of primary tin mineralization in the Sinceni West area. First, the pegmatites in this area are the most highly fractionated, as shown by Ta, Rb, and Cs concentrations in blocky K feldspar. Second, the richest mineralization occurs in pegmatites that lack tourmaline, whereas tourmaline is abundant in the barren pegmatites. A lack of tourmaline allows the buildup of boron in residual melts, which promotes extended fractionation by increasing water solubility and depressing the solidus temperature. Third, the best tin values occur in pegmatites that exhibit boudinage and other signs of ductile deformation caused by an adjacent shear zone. Microstructures show that at least some cassiterite predates the deformation and that the albitic units and wall-rock alteration are synkinematic. The ductile deformation may have influenced the distribution of residual melt and its interaction with preexisting pegmatite and wall rocks, but it was probably of minor importance for the mineralization itself.

Particle size and trace element distribution characteristics of cassiterite as an aid to provenance study of stanniferous placers in northeastern Tasmania, Australia

In order to assist a heavy mineral provenance study of stanniferous placers in northeastern Tasmania, Australia, particle size and trace element distribution characteristics of cassiterite were examined. The contents of four trace elements: niobium (Nb), tantalum (Ta), tungsten (W), and zirconium (Zr) within cassiterite were determined using wavelength X-ray fluorescence spectrometry. This was carried out to test the diagnostic value of these elements in recognizing different types of primary tin mineralization in order to provide clues on the distance of transport of cassiterite. Cassiterites from the Blue Tier and Mount Cameron Massifs have been found to show differences with the former enriched in W and the latter enriched in Nb, Ta and Zr. These differences are explained by a greisen- and a pegmatite-predominated source rock, respectively. The particle size distribution characteristics of cassiterite concentrates obtained from mines were found to be a valuable means of distinguishing between placers showing kulit, kaksa and mintjan affinities. Based on the dominance of kulit and kaksa placers found, and records of ore distribution in deep leads, it is concluded that the bulk of the economic placers in northeastern Tasmania are locally derived and do not normally exceed 1 km in distance of transport downstream of the source rock.

Physico-Chemical Factors Affecting the Separation of Cassiterite and Fluorite by Froth Flotation

Abstract Cassiterite flotation is achieved industrially with some anionic collectors. However, the presence of fluorite in primary tin ores usually poses a problem in relation to the selectivity between the two minerals. In this work, a comparative study was undertaken involving adsorption, electrophoretic mobility and suspension stability measurements of both cassiterite and fluorite as a function of oleic acid concentration. These properties are discussed with reference to the calculated free energy of adsorption equation pending of oleic acid on the two minerals. Hallimond tube flotation tests conducted with the two minerals showed a distinctly higher floatability of fluorite at low oleic acid concentration. Micro-flotation studies using Procol CA-540. a sulphosuccinamate collector, presented similar results, indicating that fluorite can be floated selectively from cassiterite at low collector concentration and neutral pH.

Geological interpretation of aeromagnetic data in some parts of northcentral Nigeria

Airborne magnetic data and field observations were used to define structural trends in some parts of North Central Nigeria. The aeromagnetic anomalies of the Jurassic Younger Granite complexes are distinctive with relatively high amplitudes and short wave-lengths and are directly associated with the outcrop patterns of the intrusions. The mosaic pattern of magnetic anomalies may be used to identify the Younger Granite ring complexes. The aeromagnetic data also contain evidence of linear structural discontinuities. some of these linear features are long and extend through the survey area. They are identified by a pattern of contour offsets and probably reflect deep crustal features cutting some of the Younger Granite known to be mineralised. In particular, a major fault is mapped which cuts the Ririwai complex to the East. This fault trending NW-SE, appears to extend southwards through the area. The lineaments probably acted as conduit through which mineralized fluid flowed. The regional trends of structures are revealed on the aeromagnetic map, these being mainly northeast-southwest and northwest-southeast. The Northwest-southeast trends are superimposed on the northeast-southwest trends. This overprinting of one magnetic anomaly trend over the other suggests that the Northeast-southwest lineaments are older than the northwest-southeast lineament patterns Three known tin-bearing ring complexes show strong magnetic anomalies which make them more prominent than the other complexes on the coloured magnetic anomaly map. This characteristic should assist in locating new provinces for primary tin deposits.

Geochronological evidence for multiple tectono-thermal overprinting events in the East Kemptville muscovite–topaz leucogranite, Yarmouth County, Nova Scotia, Canada

The East Kemptville muscovite–topaz leucogranite, located in Yarmouth County, Nova Scotia, Canada, is host rock to the only producing primary tin deposit in North America (56 Mt, 0.165% Sn). Previous geochronological studies include (i) Rb–Sr whole-rock analyses of the quartz–topaz greisens, which indicated a date of 337 ± 5 Ma, and (ii) 40Ar/39Ar analyses of greisen muscovite, which indicated apparent plateau dates of ca. 300 Ma. However, the pervasive development of deformational fabrics at East Kemptville suggests that both the Rb–Sr whole-rock and 40Ar/39Ar muscovite ages are at best minimum estimates for the inferred time of mineralization. In the present study, Rb–Sr whole-rock and mineral (muscovite, plagioclase, K-feldspar) analyses and 40Ar/39Ar incremental-step heating of a muscovite separate indicate the following: (i) diffusion of Sr on the whole-rock scale terminated at 344 ± 5 Ma (11 point isochron date), coincident with closure of muscovite to intracrystalline diffusion of Ar (apparent plateau date of 338 ± 2 Ma) and (ii) internal reequilibration of Sr among muscovite, feldspar, and whole rock varied considerably such that Rb–Sr whole rock – muscovite pairs give dates of 361–311 Ma (mean = 330 Ma, n = 7), whereas whole rock – plagioclase – K-feldspar give dates of 276–240 Ma (mean = 254 Ma, n = 7). This younger thermal event is reflected in apparent dates of 269–286 Ma for the low-temperature steps of the 40Ar/39Ar muscovite age spectrum.Collectively the data indicate that the East Kemptville area either cooled slowly over a protracted period of time (ca. 100 Ma) or experienced episodic tectono-thermal activity at ca. 344, 330, and 254 Ma. Examination of previously published geochronological data for the southern Meguma Terrane indicates that these aforementioned ages broadly coincide with earlier documented magmatic or tectono-thermal events (e.g., intrusion of Wedgeport Pluton at 315 Ma). Inferences by some workers of mid-Carboniferous magmatism in the Meguma Terrane are, however, not supported by the present study.

Sungei Isahan - A new primary tin occurrence in Sumatra

Sungei Isahan - A new primary tin occurrence in Sumatra

Undiscovered lode tin resources of the Seward Peninsula, Alaska

The United States is a net importer of many important minerals, including tin. Consumption of primary tin in the United States is about 36,000 metric tons per year. Identified U.S. tin resources consist of about 40,000 metric tons. Although such figures provide insight about vulnerability to supply disruptions in the short term, they do not provide information about the potential of a country to meet its needs for a commodity from undiscovered domestic sources. Recent developments, including the preparation of models of mineral deposits and their grades and tonnages, and the application of computer simulation techniques to the estimation of metallic mineral resources, make it possible to estimate the magnitude of undiscovered resources, by deposit type, for relatively small areas such as the Seward Peninsula. This paper uses these developments and geophysical data to estimate undiscovered lode tin resources on the Seward Peninsula of Alaska. The assessment is based on a three-step methodology that (1) identifies the types of tin deposits that may be present in the region, (2) identifies the geophysical characteristics of unroofed granites and shallow granitoids, and (3) estimates, on the basis of various combinations of geologic and geophysical conditions, the number of undiscovered deposits present within or near exposed or concealed granite plutons. Computer simulation was used to combine the estimates of the number of deposits with available grade and tonnage models. Simulation experiments were designed to estimate the amount of tin in undiscovered deposits under a variety of limiting conditions. Results of simulation experiments indicate there is a 90 percent chance that the Seward Peninsula contains at least 51,000 metric tons, a 50 percent chance that it contains at least 390,000 metric tons, and a 10 percent chance it contains at least 1,100,000 metric tons of tin in undiscovered greisen, vein, and replacement deposits that have average grades of at least 0.5 percent tin.

The composition of tin slags from the south‐west of England

This paper discusses tin slags from archaeological contexts in the south‐west of England dating from the Early Bronze Age to the nineteenth century. It also includes slags resulting from a recent experimental smelting programme. Analyses show that there has been little change in composition over this period and that most primary tin slags contain from 10–30 per cent stannous oxide in the glass phase, with tin metal prills more common in the early and medieval slags. The principal impurities in the metal are iron and antimony, with smaller amounts of tungsten and arsenic. The Devon slags differ from the Cornish ones in having larger amounts of titanium in them.

Metallogeny of tin in central Thailand: A genetic concept

Tin mineralization in central Thailand is associated with granitic rocks of the Thai-Burmese border range (western group). Granitic intrusions east of Bangkok and near the Kampuchea border (eastern group) have no tin. Fractional crystallization is the fundamental petrogenetic process that controls the evolution of both groups of granites. The tin-bearing alkali-feldspar aplogranites of the western group display an extreme degree of differentiation that has no petrological equivalent in the eastern group. These aplogranites are the product of a combination of magmatic fractionation (primary tin enrichment trend) modified by fluid interaction. The latter process is responsible for a secondary geochemical tin deficiency that is balanced by redistribution of tin in fracture systems—i.e., tin mineralization. The pattern of tin depletion in the aplogranites provides an indication of the tin potential in a given ore-forming system.

REE geochemistry and petrogenesis of some granite bodies related to tin-polymetallic deposits in Nanling region, South China

Tin-polymetallic deposits, with a characteristic elemental association of Sn, Cu, Pb, Zn, Au, Ag and sometimes Fe, W and Mo, are widespread in the Nanling region, South China. Like W-Sn-Nb-Ta-Be(REE) deposits, they are commonly associated with acid granites. Therefore, it has long been considered that tin-bearing granitic magma derived from anatexis in the tin-rich belt in the sial crust is the only source of primary tin mineralization, including the tin-polymetallic deposits discussed in this paper. Genetically they are related to the continental crust-reworked (I-type and S-type) granites.

Stanniferous placer development on an evolving landsurface with special reference to placers near St Austell, Cornwall

The geomorphic setting of the stanniferous placers of SW England is presented and the history of their development is broadly drawn. In particular, the relationships between the placers and the major types of primary tin deposit in the region are emphasized. The nature and genesis of three placer deposits in the N St Austell district are treated in some detail in order to demonstrate the complexity of placer development in the region as a whole. Stress is placed on an examination of the placer cassiterite morphology to determine the complex genesis of the Cornish deposits. Finally, it is emphasized that the initial stages of placer development in the region are due essentially to processes of disintegration, with processes of decomposition never playing more than a very minor role.

Tin Processing at the Texas City Smelter

Since 1969, Gulf Chemical and Metallurgical Company, a Division of Associated Metals and Minerals Corporation, has operated The Texas City Tin Smelter. It has transformed a complex roasting and reverberatory furnace smelting flowsheet1 to a simple flow sheet utilizing a single high speed rotary furnace. The result of this change is a more efficient smelter capable of processing primary and secondary tin bearing feed stock.

生野工場における錫製錬

Ikuno tin smelter started its operation in 1913 with the reverberatory furnace smelting process and in 1916 another plant started to recover tungsten which was contained in tin concentrates in the form of scheelite.In 1950, the company replaced the reverberatory furnace with an electric furnace to improve operation efficiency and recovery.The smelting process is composed of three stages, namely, concentrate smelting, slag smelting, and hard-head smelting. At present, smelter treats both tin concentrates mainly from Akenobe Mine and other tin bearing scrap materials to recover tin metal.Annual production of crude tin metal is approximately 1, 250 metric tons and 50% of the crude metal comes from tin bearing scrap materials.Ikuno is the only primary tin smelter in Japan.

直島製錬所の電気錫製錬

The tin refining plant at Naoshima Smelter began operation in 1960 treating crude tin produced at Ikuno Smelter, while the tin refining plant at Osaka Refinery was shut down.At the present time, the plant, the only primary tin refinery in Japan, produces electrolytic tin of more than 99.995% at a capacity of 130 t/m.

Age of tin mineralization and plumbotectonics, Belitung, Indonesia

Primary tin deposits on Belitung, Indonesia, are spatially related to Upper Triassic granites that have a Rb-Sr isochron age of 213 + or - 5 m.y. The average K-Ar age of muscovite from two cassiterite-bearing greisens is 198 + or - 4 m.y., which suggests that the tin mineralization is not a simple late-stage event in the emplacement of the granitic plutons. Lead isotope data suggest that the source of lead in galena from the tin deposits is continental crust rather than oceanic crust. Such a source is also supported by an initial 87 Sr/ 86 Sr value of 0.7139 for the Rb-Sr isochron. The part of the shelf upon which Belitung Island is located is most likely continental shelf and not a thin continental cover over a primitive arc system.

Solidification of undercooled Sn-Bi and Pb-Sb alloys

In hypoeutectic and eutectic alloys of Sn-Bi and Pb-Sb, the first phase to solidify from the melt is the nonfaceted phase, tin and load, respectively. Since primary tin and lead are poor nucleants for the second phase of the eutectic, the faceted phase, substantial undercooling below the equilibrium eutectic temperature occurs before the eutectic is nucleated. Once nucleated the faceted phase does not grow preferentially to return the melt composition to the equilibrium eutectic composition. Instead growth of a complex regular structure takes place from a melt whose composition is displaced from the equilibrium eutectic composition towards the faceted component. Reheating experiments have confirmed that the complex regular structure is rich in the faceted component. This structure grows at a temperature depressed several degrees below the equilibrium eutectic temperature. An hypothesis is presented to explain the growth of a structure rich in the faceted component at a depressed temperature.