Bismuth potassium chromates

Bismuth Potassium Chromates.—When potassium chromate, or diehromate, is added to a solution of a bismuth salt, the yellow precipitate formed, if allowed to remain in contact with the solution,... 

Sihcon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between sihcon carbide and a variety of compounds at relatively high temperatures. Sodium sihcate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal sihcide. Sihcon carbide decomposes in fused alkahes such as potassium chromate or sodium chromate and in fused borax or cryohte, and reacts with carbon dioxide, hydrogen, ak, and steam. Sihcon carbide, resistant to chlorine below 700°C, reacts to form carbon and sihcon tetrachloride at high temperature. SiC dissociates in molten kon and the sihcon reacts with oxides present in the melt, a reaction of use in the metallurgy of kon and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new sihcon nitride-bonded type exhibits improved resistance to cryohte. 

Bi(N03)3 + 3NaOH Bi(OH)3 + 3NaN03 Reaction with potassium chromate produces bismuth chromate ... 

Potassium chromate Yellow precipitate of bismuth (III) chromate... 

Derivation Interaction of bismuth nitrate and potassium chromate. 

M. M. P. Muir reported the 1 1 0-compound, bismuthyl chromate, Bi203.Cr03, or (BiO)2Cr04, to be formed by treating a soln. of bismuth nitrate with an excess of potassium chromate or dichromate, and, after the addition of a few drops of nitiic acid, boiling the mixture for a few hours until it is transformed into a red powder. The product is washed with hot water, and dried at 100°. It is also obtained by... 

White precipitates are formed when a 1% solution of cusparine is treated with phosphotungstic, phosphomolybdic or tannic acids, or with mercuric chloride or potassium mercuri-iodide. Picric acid, platinic chloride or potassium chromate give yellow precipitates, auric chloride or potassium bismuth iodide brown, and potassium ferrocyanide bluish-white (36). By treating a solution of cusparine hydrobromide with bromine water, a series of bromocusparine polybromides is obtiuned(38). 

Calcium oxide Cupric sulfate anhydrous Cupric sulfate pentahydrate Di-iron phosphide steel mfg., specialty Calcium silicon steel priming Zinc potassium chromate steel processing Bismuth... 

Bismuth chromates group Calcium chromates group Copper chromates group Iron chromates group Lead chromates group Zinc chromates group Barium chromate(VI) Barium potassium chromate Cadmium chromate Crocoite Manganese chromate Mercury chromate Silver chromate Strontium chromate Thallium chromate Tin chromate... 

The oxidizers include heavy metal oxides such as red lead (Pb304), lead dioxide (Pb02), iron oxide (Fe203), bismuth oxide (Bi203), lead and barium chromates etc., peroxides (barium peroxide) and various oxysalts of potassium and barium. 

A formulation based on antimony trisulfide (Sb2S3)-20%, potassium perchlorate (KC104)-8% and barium chromate(BaCr04)-72% (with NC as binder) is a well-known slow-burning delay formulation with a burning rate of 0.43 cm s 1. The burning rate decreases to 0.23 cms 1 on substitution of barium chromate by bismuth chromate. These formulations are safe to handle as revealed by the sensitivity data [26]. 

Potassium or sodium-potassium alloy mixed with ammonium nitrate and ammonium sulfate results in explosion (NFPA 1986). Violent reactions may occur when a metal such as aluminum, magnesium, copper, cadmium, zinc, cobalt, nickel, lead, chromium, bismuth, or antimony in powdered form is mixed with fused ammonium nitrate. An explosion may occur when the mixture above is subjected to shock. A mixture with white phosphorus or sulfur explodes by percussion or shock. It explodes when heated with carbon. Mixture with concentrated acetic acid ignites on warming. Many metal salts, especially the chromates, dichromates, and chlorides, can lower the decomposition temperature of ammonium nitrate. For example, presence of 0.1% CaCb, NH4CI, AICI3, or FeCb can cause explosive decomposition at 175°C (347°F). Also, the presence of acid can further catalyze the decomposition of ammonium nitrate in presence of metal sulfides. 

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