Pyrite hardness

Liner wear increases with the size, hardness, and sharpness of feed more than with ball size. The hardness of manganese steel corresponds to softer types of ore, while Nihard is about the same as magnetite [Moore et al.. International J. of Mineral Proce.s.sing, 22, 313-343 (1983)]. Quartz and pyrite are considerablv harder than any metals used. Rubber, being resihent, is less affected by ore hardness, and therefore has the advantage with harder ores. Low-charge volume below 35 percent results in increased wear since the liners are not protected bv a covering of ore. Several studies indicate that wear increases at least proportional to the square of mill speed in percent of critical. 

Select a tungsten carbide insert bit with no offset and conical or double cone inserts when drilling hard and abrasive limestone, hard dolomite, chert, pyrite, quartz, basalt, etc. Use bit type 7-4 to 8-3. 

It is worthy of mention that the properties of hauerite are in accordance with the conception that the Mn—S bonds are much weaker than the Fe—8 bonds in pyrite. The hardness of hauerite is 4, as compared with 6—6.5 for pyrite. All members of the pyrite group have a bright metallic luster except hauerite, which is dull. Hauerite is said to have a much smaller electrical conductivity than the others. 

Site 2 is situated on the south shore of Moore s pit (Figs. 1 2b). This site consists of i) a pyritic waste rock pile, covered with a thin veneer of Fe-oxide tailings and ii) a down stream acid drainage affected area that is characterized by a Fe oxide + sulfur-rich hard pan surface layer that overlies a stratified unit comprised of intensely altered (Fe-oxide stained) and unaltered Quaternary glaciolacustrine deposits. A small creek (product of beaver activities) flows along the eastern margin of the site into Moore s pond. 

The natural pyrite consists of yellow cubic crystals density 5.02g/cm3 hardness 6.3 Mohs melts at 1,171°C soluble in dilute acids. 

CA 53, 15567 (1959) (Sensitization of Dynamite Gelatin by 1 —5% of inert substances of high or moderate hardness such as pumice, quartz, A1203, hematite, pyrite, etc can raise deton velocity to as high as 6800 m/sec)... 

The burning of pyrites is not quite so simple a matter as the burning of sulphur, as a red heat ia required, Two varieties of pyrites are Ordinarily met with. One kind, of which large quantities are to be found in Wicklow, Ireland, and is imported into this country, to a considerable extent, for the nse of sulphuric acid manufacturers, has the crystalline form of a cube, and is of a bronze-yellow color, very hard, so much so as to strike fire with steel. The following is the composition of a specimen, on the authority of R. D. Thomson—... 

Iron is obtained from misy, a yellow, gold-appearing, hard stone (pyrites ). Pliny vaguely describes under the same name a product formed by roasting a copper ore. According to Berthelot, the misy of Pliny is the product of a gentle oxidation of copper pyrites, a mixture of basic sulphates of iron and copper.48... 

Tables 3.1, 3.2 and 3.3 compiled by Povarennykh (1963) specify the initial data accepted for the calculation of hardness from formulae (3.5) and (3.6). As the ratio WJWa increases, the coefficient a decreases (Table 3.1). For compounds with ratios inverse to those given in the table, i.e., for compounds having a so-called antistructure, the coefficient a will be exactly the same, e.g., 1/2 and 2/1. In both cases, x — 80. The link attenuation coefficient / varies over a relatively narrow range, usually between 0.7 and 1.0 (Table 3.2). This coefficient requires the state of lattice linkage to be considered in each case, and like coefficient a it depends on the type of compound involved. For various types of compounds, the values of the coefficient / may be lower taking as an example minerals in the pyrite and skutterudite group, they are as follows for compounds 2/2—0.60, for 3/3—0.48 and for 4/4—0.39. The values of the coefficient y grow proportionally with coordination number (Table 3.3). The constancy of the coefficient y depends on the constancy of the coordination number which is influenced by the valence ratio of electropositive and electronegative atoms. Lattice spacings, state of chemical bonds and electron-shell structure, and for complex compounds, also the degree of action of the remain-...

STANNITE (Mineral). This mineral is a sulfo-stannate of copper and non, sometimes with some zinc, corresponding to the formula. Uii PeSnS j It is tetragonal brittle with uneven fracture hardness, 4 specific gravity, 4.3-4.5 metallic luster color, gray to black, sometimes tarnished by chalcopyiite stieak, black opaque. The mineral occuts associated witli cassilerile, chalcopyiite. tetrahedrite, and pyrite, probably the result of deposition by hot alkaline solution. Stannite occurs in Bohemia Cornwall, England Tasmania Bolivia, and in the United States in South Dakota. It derives its name from the Latin word for tin, stannum. 

Some general problems associated with the determination of sulfur in coal are nonuniform distribution of pyrite particles, failure to convert all the sulfur to sulfate, and loss of sulfur as sulfur dioxide during the analysis. The nonuniform distribution of pyrite necessitates the collection of many sample increments to ensure that the gross sample is representative of the lot of coal in question. Pyrite particles are both hard and heavy and have a tendency to segregate during the preparation and handling of samples. Because the particles are harder, they are more difficult to crush and pulverize and tend to concentrate in the last portion of material that remains from these processes. 

The scratch hardness of coal can be determined by measuring the load on a pyramidal steel point required to make a scratch 100 xm in width on the polished surface of a specimen. The scratch hardness of anthracite is approximately six times that of soft coal, whereas pyrite is almost 20 times as hard as soft coal (Table 8.3). Similar data were noted for anthracite and cannel coal, but durain, the reputedly hard component of coal, was found to be only slightly harder than vitrain and cannel coal. 

Table LXVI shows the correlation coefficients obtained for the hard and soft types. The existence of two clay populations limits the meaning of correlations found for the combined data (Hinckley, 1961). In both groups K20 and mica and K20 and Fe203 are positively correlated. In addition, for the soft type there is a positive correlation between Fe203 and mica and negative correlations between mica and books, and Fe203 and books. These interrelations suggest, but do not prove, that books are derived from the mica and that much of the K20 and Fe203 may be present in the mica or that a leaching process that altered the mica and removed its interlayer K20 also removed the iron regardless of where it occurred (pyrite, anatase, iron oxides, etc.).

High levels of sulfate in water tends to form hard scales in pipes and other equipment under high temperature, gives water a bad taste, and may induce diarrhea. Sulfate-rich waters are commonly found in areas where the geologic strata is rich in sulfides (e.g., pyrite). For additional information, see Shelton (1989). 

Ruthenium Sesquisulphide, RuaSs, occurs in the platinum washings of Borneo and Oregon as the rare mineral lauriie, usually in the form of minute octahedra hardness 7-5, density 6-99. It has a bright metallic lustre and contains a little osmium. Deville and Debray 5 prepared a similar sulphide artificially in the form of isometric crystals, octahedra, and cubes by heating ruthenium with pyrites and borax. 

Platinum is found in combination with arsenic as the rare mineral sperrylite, PtAs2, at Vermillion Mine in Ontario, Canada. It was first discovered by Sperry (whence its name) in 1887 along with copper and iron pyrites in contact with gold ore. It crystallises in cubes or, less frequently, in oetahedra hardness, 6-7 specific gravity, 10-602 at 20° C. It is tin-white in colour, possessed of metallic lustre, and contains traces of rhodium and antimony.4... 

Iron pyrites, pyrite, marquisite, or mundic is the name given to a brass-coloured sulphide of iron to which the formula FeS2 is usually ascribed. It often occurs in coal, and is known by miners as brass or fool s gold. The spontaneous combustion of coal is frequently facilitated by the oxidation of iron pyrites to iron sulphate.6 It often crystallises in cubes, the faces showing striations but a very characteristic form is the pentagonal dodecahedron, usually termed the pyritohedron. Hardness 6 to 6-5 density 4 8 to 5-2. It leaves a greenish or brownish-black streak. 

Cobalt-nickel pyrites, (Fe, Co, Ni)Sa, has been found in Westphalia as small cubic crystals, steel-grey in colour, giving a greyish-black streak.3 Density 4 7, hardness 5 to 5 5. Iron nickel pyrites, (Fe,Ni)S2, occurs in Norway 4 and in the Sudbury district, Ontario.5... 

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