Sodium antimonate arsenate

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. 

Wet Process. The sodium arsenate and stannate slag are treated by a leach and precipitation process to produce calcium arsenate, calcium stannate, and a sodium hydroxide solution for recycle. The sodium antimonate filtercake containing selenium, tellurium, and indium is treated in a special metals refinery to recover indium and tellurium. 

The oxides and acids of antimony resemble those of arsenic, except that antimony in antimonic acid has coordination number 6, the formula of antimonic acid being HSb(OH)3. A solution of potassium antimonate, K+[Sb(OH)g], finds use as a test reagent for sodium ion sodium antimonate, NaSb(OH)3, one of the very few sodium salts with slight solubility in water (about 0.03 g per 100 g), is precipitated. The. antimonate ion condenses to larger complexes when heated this condensation may ultimately lead to macromolecular structures, such as... 

Over the years, copper metal production stopped for economic reasons, but numerous other products were added for environmental reasons and to maximize economic return from the concentrates treated. In many cases, technical innovation played a significant role in developing the required processes. The list of products sold today includes zinc, lead, silver, gold, indium, germanium, bismuth, cadmium, calomeL sulphuric acid, liquid sulphur dioxide, ammonium sulphate f tilizers, coppa sulphate, coiqier arsenate, sodium antimonate and ferrous granules. 

Lead Operations treats zinc plant residues, lead concentrates, recycled batteries, and lead bullion to produce silver, gold, bismuth, arsenic metal, copper sulphate, copper arsenate, sodium antimonate and about 100,000 t/a of refined lead. The lead smelter has been well described previously (2). Key aspects of the lead process flowsheet, as shown in Figure 3, are described herein. 

Also included in Lead Operations are a lead allo3rs plant, a copper products plant, and an effluent treatment plant. The lead alloys plant produces arsenic-lead and antimony-lead alloys from the treatment of softener slag and silver refinery baghouse dust. The copper products plant produces copper sulphate, copper arsenate and sodium antimonate fi"om the treatment of copper matte and refinery baghouse dusts. The effluent treatment plant treats effluents from the zinc and lead operations as well as surface runoff from throughout the metallurgical operation. 

The removal of small quantities of arsenic from metals and ores is a commercial problem which may be mentioned at this point. The Harris process of softening lead,6 used in several refineries, is based on the principle that such impurities as arsenic, antimony and tin may easily be oxidised and in the presence of certain alkali salts can he converted into arsenates, antimonates and stannates. Certain fluxes, such as sodium nitrate, sodium hydroxide, sodium chloride or lead oxide, are added to the molten lead, the presence of an oxidising agent and an alkali salt being essential. The alkaline slag obtained is fused 7 and... 

D. 17 (a) telluric acid (b) sodium arsenate (c) calcium selenite (d) barium antimonate (e) arsenic acid ... 

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