Lead metal

The cmde lead and discard slag from the reduction furnace are tapped continuously through a single taphole into molds. The discard slags have a 1 to 2% lead oxide content and 1 to 2% of lead metal prills (pellets). 

In 1986 Britannia Refined Metals (Northfleet, U.K.) introduced technology for the treatment of Parkes cmst, a triple alloy of Ag, Zn, Pb, which by 1992 had been adopted by seven lead refineries (22). The technology consists of a three-stage process in which the silver-rich cmst is first Hquated to reduce its lead content, then placed in a sealed furnace where the 2inc is removed by vacuum distillation and, finally, the silver—lead metal is treated in a bottom blown oxygen cupel (BBOC) to produce a Htharge slag and dorn metal. 

Reverberator Furnace. Using a reverberatory furnace, a fine particle feed can be used, the antimony content can be controlled, and batch operations can be carried out when the supply of scrap material is limited. However, the antimony-rich slags formed must be reduced in a blast furnace to recover the contained antimony and lead. For treating battery scrap, the reverberatory furnace serves as a large melting faciUty where the metallic components are hquefted and the oxides and sulfate in the filler material are concurrently reduced to lead metal and the antimony is oxidized. The furnace products are antimony-rich (5 to 9%) slag and low antimony (less than 1%) lead. 

Sodium nitrite has been synthesized by a number of chemical reactions involving the reduction of sodium nitrate [7631-99-4] NaNO. These include exposure to heat, light, and ionizing radiation (2), addition of lead metal to fused sodium nitrate at 400—450°C (2), reaction of the nitrate in the presence of sodium ferrate and nitric oxide at - 400° C (2), contacting molten sodium nitrate with hydrogen (7), and electrolytic reduction of sodium nitrate in a cell having a cation-exchange membrane, rhodium-plated titanium anode, and lead cathode (8). 

Some friction materials may contain other potentially harmfiil materials. Lead has been found in some secondary linings. Class B and C organic disk pads, and other friction materials as lead metallic particles, oxides, and sulfides. Several original equipment and aftermarket suppHers are known to have a pohcy against incorporation of lead or other potentially harmfiil materials in thek products. 

The second set of experiments was carried out in 1929 by Paneth. The decomposition of tetramethyllead was carried out in such a way that the decomposition products were carried by a flow of inert gas over a film of lead metal. The lead was observed to disappear with re-formation of tetramethyllead. The conclusion was reached that methyl radicals must exist long enough in the gas phase to be transported from the point of decomposition to the lead film, where they were reconverted to tetramethyllead. 

Latin American Crop Protection Association (LACPA), 259 Latvian histihite of Organic Synthesis (OIS), 262 Latvian Ministry of Eiivironmental Protection and Regional Development, 283 Laurel Industries Inc., 236, 241 Laxnii Organic hidustries Ltd., 173 Lead - metallic and inorganic compomids, 82 Lead acetate, 82 Lead arsenate, 82 Lead chloride, 82... 

The use of dibromodifluoromethane with zinc [26] or lead metal [27] is a simple, economical method for generating difluorocarbene under mild conditions, but the reaction is limited to highly nucleophilic olefins (equation 8)... 

One problem with heterogeneous catalysis is that the solid catalyst is easily poisoned. Foreign materials deposited on the catalytic surface during the reaction reduce or even destroy its effectiveness. A major reason for using unleaded gasoline is that lead metal poisons the Pt-Rh mixture in the catalytic converter. 

Lead azide, Pb(N,)2, is used as a detonator, i i) What volume of nitrogen at STP (1 atm, 0°Ci does 1.5, of It id azide produce when it decomposes into lead metal and nitrogen gas (b) Would 1.5 g of mercury(ll) azide, Hg(N which is also used as a detonator, produce a larger or smallei volume, given that its decomposition products i c elemental mercury and nitrogen gas (c) Metal azides in general are potent explosives. Why ... 

C19-0050. What are the half-reactions for these redox processes (a) Aqueous hydrogen peroxide acts on Co, and the products are hydroxide and Co , in basic solution, (b) Methane reacts with oxygen gas and produces water and carbon dioxide, (c) To recharge a lead storage battery, lead(II) sulfate is converted to lead metal and to lead(IV) oxide, (d) Zinc metal dissolves in aqueous hydrochloric acid to give ions and hydrogen gas. 

Synonym(s) Lead metal plumbum olow (Polish) pigment metal Lead(2+) acetic acid plumbous acetate Initiating explosive (lead azide, dextrinated type only) Lead (II) bromide d... 

Domestic lead metal production rose at an annual rate of 1.3% between 1990 and 1996, going from 1.33 million metric tons to a record high of 1.43 million metric tons. Primary lead production declined at an annual average rate of 3.2% during this time period, dropping from 404,000 metric tons in 1990 to... 

Imports of lead metal, which accounted for 17.5% of U.S. domestic consumption in 1996, rose from 90,900 metric tons in 1990 to 268,000 metric tons in 1996 and dropped slightly to an estimated... 

Exports of lead metal increased from 55,500 metric tons in 1990 to 94,400 metric tons in 1991, then fell to 44,000 metric tons in 1996 and 37,400 metric tons in 1997. In 1997, the U.S. exported lead metal primarily to South Korea, Canada, United Kingdom, Malaysia, Belgium, and Taiwan. Lead waste and scrap exports, which amounted to 71,900 metric tons in 1990, rose to 104,300 metric tons in 1995, dropped to 85,300 metric tons in 1996, and rose to 88,400 metric tons in 1997. The lead content of exported scrap lead-acid batteries went from 4,800 metric tons in 1990 to 1,400 metric tons in 1995. No later export tonnage figures for scrap lead-acid batteries are available for 1996 because the data were collected by dollar value only. Most exports are in the form of lead-acid batteries or products containing either lead-acid batteries or other applications of lead (Larrabee 1998 Smith 1998). 

Reportable Quantity Adjustment for Lead Metal, Lead Compounds, Lead-containing Hazardous Wastes, and Methyl Isocyanate-Final rule (40 CFR 117, 302, and 355) lead... 

Larrabee D. 1998. Comments on chapter 4 of the draft toxicological profile for lead/metals division. U.S. Department of Commerce, February 11, 1998. 

Betterton-Kroll A metallurgical process for removing bismuth from lead. Metallic calcium and magnesium are added to the molten lead, causing precipitation of the sparingly soluble CaMgBi2. 

Elemental carbon, whether it is soot, diamond, graphite, buckyballs, or graphene, contains only carbon atoms, each of which has exactly six protons in its nucleus. Lead (Pb) is a metallic element. Lead metal contains only lead atoms, each of which contains exactly 82 protons in its nnclens. Neon gas, familiar in neon lights, contains only neon atoms and each of these has jnst 10 protons in its nucleus. Elements are the bnilding blocks ont of which all matter is constitnted. 

Lead Metal - widely distributed in environment when used as a gasoline additive and in paint. Now banned from use in gasoline and paint. Potent child neurotoxicant... 

Many commercial processes have been developed for manufacturing basic lead carbonate. These include Thomson-Stewart process, Carter process, and Dutch process. The method of preparation involves treating lead with acetic acid vapors in the presence of carbon dioxide at 60°C. In the Thomson-Stewart process, finely divided lead monoxide or lead metal is mixed with water to give aqueous slurry, which is then mixed with acetic acid in the presence of air and carbon dioxide. All these processes are slow, taking weeks to obtain products of desired composition. 

The oxide can be reduced to metalhc lead by hydrogen, carbon, carbon monoxide and other reducing agents when heated at elevated temperatures. Such reduction with carbon or carbon monoxide is carried out at about 1000°C in a blast furnace to produce lead metal ... 

Lead nitrate is prepared by dissolving lead metal, lead monoxide or lead carbonate in excess dilute nitric acid followed by evaporation of and/or cooling the solution for crystallization. 

Salt A chemical compound formed when the hydrogen of an acid has been replaced by a metal. Salts take their names from the metal and acid which form them, e.g. lead nitrate, from lead (metal) and nitric acid. 

As before, the subscript s denotes solid phases, and the subscript aq denotes solvated ions in solution. As a result of this process, a deposit of lead metal is formed on the electrode surface at the end of the cathodic scan while CO2 diffuses to the... 

Upon repetitive cycling of the potential scan, the voltammetric record is reproduced, but an additional cathodic peak near to -0.45 V appears. This is due to the reduction of Pb + ions electrochemically generated by the previous oxidation of lead metal. The reduction of lead ions occurs at a potential different from that at which the reduction of PbCOs takes place. In repetitive voltammetry, additional anodic peaks appear at -0.40 and -0.28 V. These are due to the oxidative dissolution of different lead deposits generated in reductive scans [130, 131]. 

XRD [132] and AFM [130] data suggests that the electrochemical mechanism involves a solid state epitactic transformation of lead oxide to lead metal. 

In some cases, the deposit of lead metal also consist of irregular aggregates far from the original particles of the lead compound [126], as can be seen in Fig. 2.10 for minium (Pb304)—another widely used pigment These features can be rationalized, assuming that the electrochemical pathway represented by Eq. 2.6 can eventually be coupled by a reductive process via formation of Pb + in solution... 

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