White lead manufacture

Copper fused with white lead. Manufactured bell-metal. 

The most widely used opaque white pigment was basic carbonate white lead, manufactured by a process little different from that known by the early Greeks in 400 B.C. Other commonly used pigments were zinc oxide, dating back to 1770 zinc sulfide, first produced in 1783 lithopone, developed in 1847 and basic sulfate white lead, which first appeared in 1855. 

Carter lead n. White lead manufactured in the USA. by what is known as the Carter process. This is somewhat similar to the... 

Carbon dioxide is used as a chemical reagent in the manufacture of sodium saHcylate, basic lead carbonate or white lead, and sodium, potassium, and ammonium carbonates and bicarbonates. 

The concept of the corrosion process, derived from the Latin corrodere (to eat away, to destroy), first appeared in the Philosophical Transactions in 1667 [2]. It was discussed in a German translation from the French on the manufacture of white lead in 1785 and was mentioned in 1836 in the translation of an English paper by Davy on the cathodic protection of iron in seawater [3]. However, almost until the present day, the term was used indiscriminately for corrosion reaction, corrosion effects, and corrosion damage. Only in DIN 50900, Part I, were these terms distinguished and defined [4] (see Section 2.1). 

Gaseous CO2 is extensively used to carbonate soft drinks and this use alone accounts for 20% of production. Other quasi-chemical applications are its use as a gas purge, as an inert protective gas for welding, and for the neutralization of caustic and alkaline waste waters. Small amounts are also used in the manufacture of sodium salicylate, basic lead carbonate ( white lead ), and various carbonates such as M2CO3 and M HC03 (M = Na, K, NH4, etc.). One of the most important uses of CO2 is to manufacture urea via ammonium carbamate ... 

Vinegar and Pyroligneous Acid. Vinegar (acetic acid) is mentioned several times in the Bible, as, for example, in Proverbs 10, 26 As vinegar to tire teeth and as smoke to the eyes, so is the sluggard to them that send him. It was known to Theophrastus three centuries before the birth of Christ, and was used in tire manufacture of white lead and verdigris and in extracting mercury from cinnabar (I). 

Oxychloride of Lead.—This is a compound lately introduced by Mr. Pattison, who has obtained a patent for its manufacture. It is described 5s possessing properties which are superior to those of white lead, inasmuch as it does not so readily blacken with sulphide of hydrogen as the latter body. To prepare it, the patentee dissolves pure chloride of lead in water, at the temperature of 212°, in quantities averaging five-sixths of a pound to a cubio foot of liquid. Soda, potsssa, lime, or baryta in the caustic or hydrated stats, may be employed to precipitate the lead from the solution, but as lime is the cheapest, it is of course preferred. 

The manufacture of white lead is described by Vitruvius as previously by Theophrastus, and as later by Dioscorides and Pliny. The process of making verdigris from copper is also given by Vitruvius as in Theophrastus and as later by Dioscorides and by Pliny. Theophrastus and Dioscorides name it ios. Vitruvius and Pliny call it aeruca (bronze or copper rust). 

SPERRY PROCESS. An electrolytic process for the manufacture of lead carbonate, basic (white lead) from desilivenzed lead containing, some bismuth, The impure lead forms the anode. A diaphragm separates anode and cathode compartments, and carbon dioxide is passed into the solution. Impurities, including bismuth, remain on the anode as a slime blanket,... 

This consists of a basic carbonate, corrc-sponding in composition approximately with the formula, 2pbC0 Pb(OH), It may contain various impurities resulting from the manufacture, especially basic lead acetate and it may he adulterated with barium sulphate, lead sulphate, zinc white, bone-ash, witlicrite, gyi>sum, chalk or clay (kaolin). Mixtures of white lead with barium sulphate an given special names, e.g. Venetian white (equal weights of white lead and barium sulphate), Hamburg white (l part of white lead to i parts of barium sulphate), Dutch white (i part of white lead to 3 parts of barium sulphate). Wliite lead mixed with gum and moulded into cakes is termed Krem s white. 

The use of a secondary salt has been applied in the manufacture of white lead.2 Luckow recommends as electrolyte a 1 5 per cent, solution of a mixture consist-... 

Basic lead chromate [PbCr04 Pb(0H)2] may be used as an orange-red pigment it is an excellent corrosion inhibitor. It is manufactured by boiling white lead (PbC03) with a solution of sodium dichromate. 

This method has a great advantage as lead of any grade may be used the impurities which are more noble than the lead itself, and for this reason cannot be anodically dissolved form a porous metallic slime on the surface of the anode which will be removed at regular intervals. For this reason electrolytically manufactured white lead has a higher degree of purity than that prepared by any chemical method. 

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