Gray antimony

Stibnite. (gray antimony antimony glance an-timonite). Sb2S3. 

Antimony sulphide, black 4132 8b2Sa Antlmonlus sulphldei antimony gianca antimony trisulphide cruda antimony gray antimony sesqulsulphuret of antimony stibnlte antimonita aulphide of antimony sulphuret of antimony ter-sulphuret of antimony. 

Aiiittmny gUmce, Sb.jS3 also known by the names gray antimony ore, stibiiite, or antimonite. It contains 7T4 per cout. of antimony and SS G per cent, of sulphur. 

The niter and fresh caustic soda, required to maintain the fluidity of the salt bath in the reactor chamber, are added gradually. When the color of the saturated salts turns from a dark gray to white, the impurity metals are at their highest state of oxidation, and the lead content of the spent salts is very low. In a modification, the arsenic and tin are selectively removed as sodium arsenate and sodium stannate, followed by the removal of antimony as sodium antimonate. 

A rapid method to determine the calcium content of lead alloys is a Hquid-metal titration using lead—antimony (1%) (9). The end point is indicated by a gray oxide film pattern on the surface of a sohdifted sample of the metal when observed at a 45° angle to a light source. The basis for the titration is the reaction between calcium and antimony. The percentage of calcium in the sample can be calculated from the amount of antimony used. If additional calcium is needed in the alloy, the melt is sweetened with a lead—calcium (1 wt %) master alloy. 

Tin exists in two ahotropic forms white tin (P) and gray tin (a). White tin, the form which is most familiar, crystallizes in the body-centered tetragonal system. Gray tin has a diamond cubic stmcture and may be formed when very high purity tin is exposed to temperatures well below zero. The ahotropic transformation is retarded if the tin contains smah amounts of bismuth, antimony, or lead. The spontaneous appearance of gray tin is a rare occurrence because the initiation of transformation requires, in some cases, years of exposure at —40° C. Inoculation with a-tin particles accelerates the transformation. 

Antimony may be added to copper-base alloys such as naval brass. Admiralty Metal, and leaded Muntz metal in amounts of 0.02—0.10% to prevent dezincification. Additions of antimony to ductile iron in an amount of 50 ppm, preferably with some cerium, can make the graphite fliUy nodular to the center of thick castings and when added to gray cast iron in the amount of 0.05%, antimony acts as a powerflil carbide stabilizer with an improvement in both the wear resistance and thermal cycling properties (26) (see Carbides). 

Nitrogen is a colorless diatomic gas. Phosphorus has several elemental forms, but the most common is a red solid that is used for match tips. Arsenic and antimony are gray solids, and bismuth is a silvery solid. Classify these elements of Group 15 as metals, nonmetals, or metalloids. 

The structures of antimony and bismuth correspond to that of gray arsenic. With increasing atomic weight the distances between adjacent atoms within a layer and between layers become less different, i.e. the coordination polyhedra deviate less from a regular octahedron. This effect is enhanced under pressure (cf. next section). 

Bakufuh. Detonating Explosive or Exploding Powder. A light-gray to tan pdr consisting of MF (Mercuric Fulminate) 28.8, K chlorate 37.7, Antimony trisulfide 31.5 abrasive 2%. Accdg to documents, Mks I III are used in ammunition primers while Mk 2 is used in fuze primers (Ref 1, p 25 Ref 5, pp 362—63). 

Raibun (Enka) (Thunder Powder or Smoke and Fire) consisted of K chlorate 60 Arsenic Sulfide 40%. Lt gray to tan powder used in fuze and pyrotechnic primers. Comp with Bakufun (Ref 1, p 25 Ref 5, p 369, where its compn is erroneously given as K chlorate 60 Antimony sulfide 40%)... 

On warming, gray (or a) tin, with a cubic structure changes at 13.2°C into white (or j0) tin, the ordinary form of the metal, which has a tetragonal structure. When tin is cooled below 13.2°C, it changes slowly from white to gray. This change is affected by impurities such as aluminum and zinc and can be prevented by small additions of antimony or... 

Reilly (Ref 1) describes a gray mixt made by mixing 7 parts of meal powder with 100 parts of sulfur, and is mostly used for the manuf of fire balls (used in war). These consist of twill bags, charged with compressed gray mixture, which is filled into them with the aid of spirit they are fired by means of a composition fuse. Gray mixture mixed with antimony sulfide is used for torches. 

Bismuth(III) oxide, Bi O is the compound produced by heating the metal, or its carbonate, in air. It is definitely a basic oxide, dissolving readily 111 acid solutions, and unlike the arsenic or antimony compounds, not amphiprotic in solution, although it forms stoichiometric addition compounds on heating with oxides of a number of other metals. It exists in three modifications, white rhombohedral, yellow rhombohedral, and gray-black cubical, Bismuth(II) oxide. BiO, has been produced by heating die basic oxalate. 

BOULANGERITE. A mineral compound of lead-antimony sulfide, PbjSb Sn. Crystallizes in the monoclinic system hardness, 2.5-3 specific gravity, 6.23 color, lead gray. 

BOURNONITE. An antimony-copper-lead sulfide corresponding to the formula PbCuSbS3. It is orthorhombic, and repeated twinning often produces crosses or wheel-shaped crystals. It is brittle fracture, subconchoidal hardness, 2.5-3 specific gravity, 5.83 luster, metallic color and streak, dark gray to black opaque. 

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