Individual Sulfide Research Articles

The CuFeNi sulfide component of the amphibole-rich veins from the Lherz and Freychinède spinel peridotite massifs (Northeastern Pyrenees, France): A comparison with mantle-derived megacrysts from alkali basalts

The orogenic-type spinel peridotite massifs of Lherz and Freychinède (Northeastern Pyrenees, Ariège, France) were tectonically emplaced along the North Pyrenean fault. They have been cross-cut by Cretaceous alkali basalts, a few kilometres below the Moho. These magmas crystallized at about 1.0–1.5 GPa as veins of amphibole-rich pyroxenites, containing garnet, and also occasionally as phlogopite hornblendites. In spite of the low volume of trapped silicate liquid, the veins contain up to 1900 ppm S, up to 140 ppm Cu and up to 10 ppb Pd. Under the microscope, the sulfides occur as isolated inclusions within magmatic phases (orthopyroxene, clinopyroxene, amphibole, garnet, spinel, ilmenite), irrespective of parting, cleavage or exsolution planes, or as interstitial grains among the major phases, showing signs of textural equilibration. The sulfide inclusions are interpreted as resulting from entrapment of an immiscible sulfide liquid during magmatic crystallization of the veins. However, a detailed comparison with sulfide inclusions from Cpx- and Al-augite megacrysts entrained in continental basalts shows that post-trapping structural and compositional rearrangements have probaly occurred, in response to cooling, deformation and recrystallization of the veins in the lithospheric mantle. Except in the thinnest veins where subsolidus re-equilibration of the Ni partitioning has occurred between the veins and their host peridotites, the sulfide inclusions are predominantly composed of slightly nickeliferous pyrrhotite, coexisting with subordinate amounts of pentlandite and chalcopyrite. Bulk chemistry recomputed from modal proportions and microprobe analyses of each individual sulfide in ∼ 500 inclusions is as follows: 54% Fe, 5.5% Ni, 2.0% Cu and 38.0% S. A calculation combining this composition and the experimentally determined distribution coefficients for Ni and Cu between sulfide melt and silicate melt leads to < 200 ppm Ni and > 85 ppm Cu in the silicate melt at the time at which the sulfide liquid became immiscible. It is concluded that the alkalic basaltic magma parent to the amphibole-rich veins reached sulfide saturation at depth of ∼ 30–40 km, i.e. after some differentiation occurred in the uppermost lithospheric mantle.

Free-Radical Thiylation of Di-, Tri-, and Tetrachloroethylenes and 1,1,2-Trichloropropene with Organyl Thiols and Diaryl Disulfides

Abstract UV-Irradiation and benzoyl peroxide initiated radical reactions of the title ethenes with aliphatic and aromatic thiols and diaryl disulfides are presented. From these reactions individual unsaturated sulfides RSCX[dbnd]CYZ (X, Y, Z = H, Cl, CH3) or mixtures of the above isomeric sulfides and saturated sulfides RSCXX′CX″X″′Y (X, X′, X″, X″′ = H, Cl; Y = H, Cl, CH3) have been obtained. The reaction features in each given case and differences in the reaction course for thiols and disulfides are discussed. Reaction mechanisms explaining the differences in the process in each particular case are suggested.

Base metal mineralization in the Kanmantoo Group, South Australia; a regional sulfur isotope study

A number of base metal sulfide deposits are hosted by multiply deformed metagraywackes of the Kanmantoo Group, South Australia. Sulfide mineralization is of three main types: (1) copper deposits which include the Kanmantoo and Bremer mines, South Hill prospect, and several minor occurrences; (2) lead-zinc deposits at the Aclare, Wheal Ellen, and Strathalbyn mines; (3) pyrite-pyrrhotite mineralization of the Nairne pyrite deposit and other pyritic schists within the Kanmantoo Group.Copper deposits are discordant and pipelike and contain chalcopyrite, pyrrhotite, magnetite, and pyrite as the major opaque minerals. Lead-zinc deposits lack magnetite and are apparently concordant. Beds of pyritic schist reach an overall thickness of 100 m and persist for as much as 32 km.Sulfur isotope ratios for ore shoots from the Kanmantoo mine, excluding one sample, range from 3.5 to 12.4 per mil and average 8.0 + or - 2.3 per mil. Average values for individual ore shoots differ by as much as 4 per mil. 34 S enrichment is noted at Kanmantoo among some low-grade sulfide mineralization (delta 34 S = 16ppm) and supergene pyrite from the main orebody (delta 34 S = 39.6ppm). The minor deposits of copper and lead-zinc all show a similarity in sulfur isotope composition. The delta 34 S values for sulfides range from -4.7 to 6.5 per mil and averages for these deposits lie close to zero per mil. The pyritic schists are strongly depleted in 34 S and contain biogenic sulfur formed in an anoxic marine environment; individual sulfides range from -19.9 to -11.9 per mil. Isotopic disequilibrium is a characteristic feature of coexisting sulfide pairs from many of the deposits, despite subsequent amphibolite facies metamorphism (3.8 kb and 500 degrees -600 degrees C). Sphalerite-galena pairs at the Wheal Ellen mine yield consistent calculated temperatures (379 degrees C) and may have reequilibrated below the metamorphic peak.Base metal mineralization is accounted for by subsurface (copper) and sea-floor (lead-zinc) accumulation from hydrothermal fluids circulating to or expelled from depths of at least 3 to 4 km within the sedimentary basin. This minimum depth estimate for fluid extraction corresponds to the stratigraphic interval occupied by pyritic schists, which underlies the horizon of base metal mineralization. Sulfur isotope evidence suggests that sulfur was extracted by hydrothermal leaching from the pyritic schists. Sulfur within the base metal mineralization shows a mixed Cambrian seawater and biogenic (pyritic schist) source. Variations in mixing proportions of the two forms of sulfur are responsible for differences among ore lenses at the Kanmantoo mine and individual deposits within the region.

Copper metallogeny in the Jogimardi Volcanics, Chitradurga Greenstone Belt

Abstract Massive volcanic-hosted sulphide deposits, within the Jogimardi volcanic suite (JVS) are Cu-rich with minor Zn and Pb and form an important early phase in the evolution of the late Archaean Chitradurga belt. The deposits are concordant stratabound lenses in the bedded mafic tuffs emplaced as submarine volcaniclastites. The JVS is an integral part of the Chitradurga antiform flanked by synclines on either side. The stratiform massive and vein-type sulphide deposits of the JVS are confined to the eastern limb of the antiform. The volcanic rock succession in the JVS consists of 85% tholeiitic basa1ts; 12% low silica variolitic andesites and 3% of rhyolites. The basalts are quartz-normative tholeiites, not known to occur in MORB environment. Unlike those of MORB, in their major, minor and REE geochemistry, the basalts related to massive sulphide deposits are almost identical to back-arc basalts generated in an ensialic marginal basin environment. The thermal and chemical environment of ore formation are determined based on fluid inclusions data and d34S pyrite values of individual sulphide phases. These data indicatce that the ores were deposited under anoxic chemical environment at a temperature of 350°C within a pH range of 5 to 7 corresponding to proximal facies conditions. The stratiform sulphide ore body in the area is located in the vicioity of a fracture controlled stringer/stock-work ore zone - 'a hydrothermal discharge vent' in the pillowed basalts of tholeiitic composition which confirms the proximal nature of the deposit. Uranogenic and thorogenic lead isotope studies on the galenas of Ingladhal stratiform sulphide bodies indicate that they are not of mantle origin but derived from the basement gneisses, dated at 3 b.y. Geologic setting, preservation of quench plagioclase textures in the pillowed basalts and volcanogenic synsedimentary nature of the stratiform sulphide deposits indicate that the sulphides were deposited initially in the JVS prior to folding and regional greenschist facies metamorphism.

Oxidation of petroleum sulphides with nitrogen dioxide

1. 1. Petroleum sulphides (obtained as concentrates from appropriate distillates) were oxidized with a mixture of air and nitrogen dioxide to sulphoxides, with yields of 75 to 80% for sulphoxide sulphur, but the process was complicated by secondary processes: the formation of up to 30% of nitrosulphoxides of variable structure; sulphones and carbonyl compounds were present as traces. The target product was separated from most impurities by an alkaline wash, followed by chromatography. 2. 2. Oxidation of individual sulphides under the conditions adopted gave sulphoxides, which contained only traces of compounds with a nitro-group, easily removed by recrystallization or elution chromatography.

The effect of treatment with triethylaluminium on the hydrogenation and hydrodesulfurization activity of molybdenum, cobalt, and nickel sulfide catalysts

The activities for hydrogenation of hex-1-ene (1 atm, 573 K) and hydrodesulfurization (hds) of thiophene (1 atm, 673 K) of alumina-supported molybdenum, cobalt, and nickel sulfide catalysts, and a sulfided Co-Mo γ- Al 2O 3 catalyst have been measured before and after treatment of the catalyst with triethylaluminium (AlEt 3). The triethylaluminium treatment (a) increased the hex-1-ene hydrogenation activity of the individual sulfides; (b) decreased the hex-1-ene hydrogenation activity of the sulfided Co-Mo γ- Al 2O 3 ; (c) increased the thiophene hds activity of sulfided Mo γ- Al 2O 3 ; (d) decreased the thiophene hds activity of the other catalysts and loss of promoting effect of Co on sulfided Mo in the sulfided Co-Mo γ- Al 2O 3 catalyst. The hydrogenation activities of the catalysts decreased after they had been used for hds. The AlEt 3 treatment of the catalysts also caused changes in their electron spin resonance spectra which are attributed to reduction of oxidic Mo(V) to oxidic Mo(III) and sulfided Co(II) to sulfided Co(I). The work provides additional evidence that the active species is a Mo(IV) sulfide promoted by Co(II).

Wall-rock alteration at the Millenbach Cu-Zn mine, Noranda, Quebec

Pipe-shaped zones of altered rock containing disseminated and stockwork vein mineralization underlie each of the several Archean volcanogenic Cu-Zn ore lenses at the Millenbach mine. The rocks and mineralization have been metamorphosed first to hornblende hornfels assemblages, then retrograded to greenschist facies assemblages, but the metamorphism has not significantly affected the bulk composition of the rocks. The alteration pipes show a distinct mineralogical zoning in which a core zone containing either anthophyllite-bearing assemblages or massive chlorite grades outward into a biotite-rich zone characterized by a spotted texture. Normative calculations were used to show that alteration pipes initially had a chlorite core which graded laterally and vertically into a sericite-rich outer zone and finally into unaltered rocks. Similar zoning is present on the selvedges of individual sulfide veins within the alteration pipes. Volume was conserved, and a distinctive metasomatic trend developed across the alteration pipes and vein selvedges during the alteration process. The most characteristic features of the altered rocks are increased Fe and Mg, and decreased Ca and Na, relative to fresh rocks. K and Al have generally been added at the margins and leached at the cores of pipes. Chemical zoning across vein selvedges is similar. The zoning of alteration types on vein borders, and to a certain extent in the pipes as a whole, is interpreted as due to the progressive reaction of an initially homogeneous hydrothermal solution with the rocks as the fluid moved upward in, and outward from, permeable channelways in the discharge conduit of a submarine, sea water-dominated hydrothermal system. However, an additional cause of vertical, and to a lesser extent lateral, zoning is thought to have been the existence of a strong vertical thermal gradient, as well as lateral variations in the permeability in the pipes. The thermal gradient could have been caused by the discharge fluid column being under hydrostatic pressure and everywhere at its boiling point. The fluid was probably evolved sea water which was in equilibrium with the rocks at depth in the system and then degenerated, causing alteration and sulfide deposition as a result of cooling and chemical changes associated with boiling as it rose in the conduit systems.

Displacement of organic sulphides by amines in trans-dichlorobis(organic sulphide)palladium(II) complexes

The kinetics of nucleophilic displacement of a variety of organic sulphides RSR′ from complexes of the type trans-[Pd(RSR′)2Cl2] by amines of different basicity and steric hindrance have been measured in 1,2-dimethoxyethane at 25 °C. The overall reaction occurs in two separate stages, the first being much faster than the second. The investigated processes correspond to the reaction: trans-[Pd(RSR′)2Cl2]+ amine →trans-[Pd(RSR′)(amine)-Cl2]+ RSR′(amine = pyridine or substituted pyridine). The nucleophilic substitutions obey the usual two-term rate equation. The rate of the reactions, the discrimination of one complex against the individual entering amines, and the lability of the individual sulphides when they are displaced by a given amine are compared and discussed.

The relationship between sulfide grain size and metamorphic grade of host rocks in some strata-bound pyritic ores

New data concerning the grain size of sulfide minerals in some ore deposits surrounded by metamorphosed silicate host rocks is presented. These indicate that average grain size of ore and grain size range of individual sulfide minerals show fair correlation with metamorphic grade of host rocks.

Sewerage and Sewage Treatment: State-of-the-Art Abstracts

Abstracts of 13 ongoing research projects are given. The summaries consider activated sludge effluent, clarification processes, ecology in waste stabilization ponds, wastewater treatment by ion-exchange resins, plant operating costs, fly ash filters, wastewater aeration, individual home waste treatment systems, oxygenation, sulfides, and other problems. This paper has been prepared as an activity of the Committee with significant information on waste treatment, inclusive of subjects of research and demonstration projects.

Separation and Determination of 2, 4-Dinitrophenylsulfides by Thin-layer Chromatography

A thin-layer chromatographic method is described for the separation, identification and determination of 2, 4-dinitrophenyl sulfides. The derivatives are easily obtained from mercaptan and dinitrofluorobenzene in the presence of sodium bicarbonate at room tem-perature. The sulfides are separated on silica gel plates using a solvent mixture of benzene-xylene-carbon tetrachloride (2:1:1, v/v). The individual sulfides are determined spectrophotometrically, at 330_??_335mμ in ethanol, emax ca. 13, 000, after washing out the plate with hexane and extraction from the adsorbent with acetone.

Selenium in some Canadian sulfides

Determinations of Se contents have been made by X-ray spectrographic means on pyrite, pyrrhotite, pentlandite, and chalcopyrite from a variety of Canadian ores including a high-intensity magnetite replacement body, several nickeliferous copper sulfide (magmatic) ores of Sudbury, 9 massive, nonnickeliferous, Cu, Fe, (Zn) hydrothermal replacement ores chiefly from Quebec and Ontario, 10 pyritic gold- quartz deposits, banded siderite-pyrite (chert) deposits, Michipicoten, and pyritic, uraniferous ores of Algoma, Ontario. Richest Se concentrations are found in some of the Precambrian nonnickeliferous Cu ores, containing several hundred to 1,000 p. p. m. Se, but even in these, relatively Se-rich and Se-poor provinces are evident. One Precambrian and 2 Paleozoic Cu ores are of the latter type. The Sudbury deposits are intermediate between the 2 extremes, Se in these averaging between 50 and 100 p. p. m. in the 4 common sulfides. Pyrites in gold-quartz ores, in the banded Michipicoten deposits, and in the U ores of Algoma average less than 50 p. p. m. Se but range to below the limit of detectability (15 p. p. m.). In general no order of preference is indicated by the individual sulfides but in several Cu ores and also in the Sudbury ores the tendency is noted for the progressive concentration of Se with the order of crystallization and in some, amounts of pyrrhotite and chalcopyrite are fairly similar. It is suggested that the apparent lack of order in other deposits may be due to contamination of earlier sulfides in a restricted system by late vapors or Cu-rich fluids penetrating earlier minerals. Variations in Se with apparent temperature of formation of pyrite in a Au ore, and vertical and horizontal variations in pyrite and pyrrhotite in several of the different types of deposits are noted in addition to distance from intrusives of diabase and quartz porphyry. Se is somewhat enriched in lower temperature pyrite, a distinct enrichment is noted in the upper levels of more deeply explored deposits, McIntyre and Noranda, and variations in others occur over shorter distances. Horizontal variations with respect to intrusives are irregular to negligible in some cases, but are more regular in others, Se being highest at about 100 ft. from quartz porphyries (McIntyre) and near the contact of larger diabase dikes (Noranda and Geco). Very extensive sampling of all deposits is required before a clear picture can be obtained of the distribution of Se in a single ore deposit. The low to negligible Se content of gold-quartz deposits is attributed to Se-poor magmatic sources and/or wall rocks. In marked contrast to the Se-rich U ores of the Colorado plateau are the low-Se siderite ores of Michipicoten, also associated with tuffs, and the (non-tuffaceous) Algoma U ores in conglomerates, for the pyrite of which a hydrothermal rather than purely sedimentary origin is favored.

Geochemistry, crystal structure and mineralogy of the sulfides

The principal component metals of the sulfides and the similarities of chemical bonding and packing geometry of both simple and complex sulfides and sulfo salts are discussed. While individual sulfides and sulfo salts may differ in chemical composition, there is sufficient structural resemblance to permit the establishment of a single classification. An attempt has been made to relate the descriptive mineralogy (the physical and chemical properties) to the new classification and bonding structure.

Preparation and Tests of Refractory Sulfide Crucibles

Crucibles have been prepared from all af the sulfides of barium, cerium, and thorium, and also from some of the mixed sulfides of cerium with thorium and uranium with thorium. The type of molds used, as well as the methods of pressing of the sulfide powders, are described in detail. Sintering procedures and techniques are listed for each of the various refractories. More than 800 refractory sulfide crucibles have been produced by the authors in the Berkeley laboratories. These crucibles have ranged from extremely small containers with 0.0026 cc. capacity to crucibles with 50 cc. capacity. Tests of these crucibles indicate that they are satisfactory refractories for a large number of metals and halides. Tests of the individual sulfide refractories as containers for various melts are summarized. The individual differences, as well as similarities, of the sulfide refractories are pointed out.