Minerals cerussite

Of all the lead oxide minerals, cerussite and anglesite [1,2] have been studied the most. The flotation properties of cerussite and anglesite are different in such a way as the anglesite is less amenable to sulphidization than cerussite. The sulphidization process for both minerals is a delicate process and is sensitive to (a) level of additions of sulphidizer, (b) the number of sulphidization stages and (c) conditioning time with sulphidizer. 

An excellent example combining thermodynamics, kinetics, and equilibrium considerations was presented by O Day (1999), who considered the precipitation reaction of solid lead carbonate, in the form of the mineral cerussite (PbCOj ) according to the reaction... 

Lead nitrate, Pb NOg), is a white crystalline substance made by dissolving lead, lead monoxide, or lead carbonate in nitric acid. Lead carbonate, PbCOg, occurs in nature as the mineral cerussite. It appears as a precipitate when a solution containing the hydrogen carbonate ion, HCOg-, is added to lead nitrate solution. With a more... 

I ad(ll) carbonate Awhlte solid, PbC03, insoluble in water rhombic r.d. 6.6. It occurs as the mineral cerussite, which is iso-morphous with aragonite and maybe prepared in the laboratory by the addition of cold ammonium carbonate solution to a cold solution of a lead(II) salt (acetate or nitrate). It decomposes at 315°C to lead(II) oxide and carbon dioxide. 

Lead carbonate ( neutinl lead carbonate , PbC03) is one of the compounds which may fall under the common name of lead white (. v.). It is the synthetic analogue of the mineral cerussite q.v.), a term sometimes extended to this compound. While processes such as the stack method of manufacturing lead white tends to form the more commonly encountered lead carbonate hydroxide q.v.), some circumstances favour lead carbonate. For example, Heaton (1928) records that the Kremnitz process, which uses a paste of litharge and acetic acid or lead acetate qq.v.) exposed to carbon dioxide, may produce neutral lead carbonate. 

Lead is obtained chiefly from galena (PbS) by a roasting process. Anglesite, cerussite, and minim are other common lead minerals. 

The difference in mineralogy of the Kuroko and present-day back-arc deposits are (1) metastable phases such as native sulfur, wurtzite, and amorphous silica are poor in the Kuroko deposits (2) arsenic minerals such as jordanite, tetrahedrite-tennantite, native arsenic, and realgar are common in the present day back-arc deposits (Okinawa Myojinsho Knoll Caldera), but rare in Kuroko deposits except tetrahedrite-tennantite (3) secondary minerals such as cerussite and covellite are common in present day back-arc deposits (e.g., Okinawa, Myojinsho Knoll Caldera) (4) Dendritic texture is common in the present day back-arc deposits. 

The low solubility of Cu oxide and hydroxide minerals and relatively high solubility of its carbonate cause the preferred association of Cu with the oxide phases, such as CuFe204j that may determine the solubility of Cu2+ in soil solution (Lindsay, 1979). In soils with high pH, lead carbonate (PbC03 (cerussite)) is stable, but its solubility is still higher than that of Pb phosphates. 

In sediments of the Mezica mining and smelting area, mineral phases such as cerussite (PbC03), galena (PbS) (Fig. 2), pyromorphite (Pb5(P04)3CI), descloizite (PbZn(V04)(0H)), bindheimite... 

Excess of sulphidizer has a negative effect on cerussite and anglesite recovery. Figure 20.1 shows the effect of the level of Na2S on cerussite and anglesite recovery. These results have demonstrated that too high an addition of sulphidizer results in mineral depression. 

Why does the solubility of a salt of a basic anion increase with decreasing pH Write chemical reactions for the minerals galena (PbS) and cerussite (PbC03) to explain how acid rain mobilizes traces of metal from relatively inert forms into the environment, where the metals can be taken up by plants and animals. 

Cerussite is of secondary origin, being found associated with other lead minerals, and is widely distributed. There are many European and American localities. Fine crystals have been obtained from Phocnixvillc. Pennsylvania Joplin. Missouri Leadville. Colorado Pima County, Arizona, and Dona Ana County, New Mexico. It is an ore of lead, and frequently carries values of silver. Derived from the Latin cetussa. white lead... 

Occurrence. The single most important ore of lead is the sulfide, galena (PbS). Minerals of considerably less commercial value include anglesite (PbS04), cerussite (PbC02), and wulfenite (PbMo04). 

Some substitution of strontium (up to 14 mol.%), of lead (2 mol.% reported) but no barium has been reported in aragonite, although investigations at elevated temperatures and pressures show almost complete miscibility of these elements in the structure (Gaines et al., 1997, p. 442), and SrCOs (strontionite), BaCOs (witherite), and PbCOs (cerussite) are common minerals. A calculated plot (Figure 3(b)) for cations in ninefold coordination shows that this coordination theoretically allows trivalent rare earth elements and quadravalent and many other elements to be substituents in the structure. Ytterbium, europium, samarium, and radium carbonates with aragonite structure have been synthesized (Spear, 1983). 

Wastes from lead-rich mineral deposits typically form anglesite in sulfate-dominant environments, but in limestone-dominated host rocks and in gangue containing abundant carbonates, both cerussite [PbCOs] and hydrocerussite [Pb3(-003)2(01-1)2] have been reported as secondary minerals in mining-related wastes. Several carbonate and hydroxycarbonate minerals of copper and zinc were reported by Hudson-Edwards et al. (1996) as secondary products in stream sediments in the Tyne Basin, England. 

The most common lead ore is galena (lead sulfide, PbS 87% Pb), followed by anglesite (lead sulfate, PbS04 68% Pb), and cerussite (lead carbonate, PbCOj 77.5% Pb). The two latter minerals originate from the natural weathering of galena. Other elements fre-... 

The most important Pb ore is the heavy black mineral galena (PbS), while other ore minerals are anglesite (PbS04), cerussite (PbC03) and pyromorphite (Pb5(P04)3Cl). 

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