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Water leach, zinc oxides

The process begins with a weak acid leach (pH 1.5-1.8) followed by a pH bump to 3.8-4.0 for iron, silica, arsenic and antimony precipitation. The slurry is thickened, and the solid residues are filtered and washed to recover water-soluble zinc in two stages of American disk filters. This filtration step is being upgraded as described in a following section. These iron-rich residues are then repulped and combed with the residue slurry from the oxide leaching circuit and are pumped to the smelter where the slurry is filtered, combined with other materials and process in the JCIVCET furnace. [Pg.445]

After pretreatment by roasting to form metal oxides, the next general purification step for many metals is to chemically treat the metal oxides by using aqueous solutions to leach out the metal. The chemical solution selected for treatment depends on the metal oxide. As examples, zinc oxide will dissolve into an acidic solution, copper oxide forms a water-soluble complex ion when mixed with ammonia and ammonium chloride in water, and tin oxides can be dissolved in fluoroboric acid. The water solutions can then be reacted to obtain specific metal salts, or electroplating techniques can be used to plate out the desired metal. Plating solution waste can either be destroyed or reclaimed. [Pg.93]

Production and Economic Aspects. Thallium is obtained commercially as a by-product in the roasting of zinc, copper, and lead ores. The thallium is collected in the flue dust in the form of oxide or sulfate with other by-product metals, eg, cadmium, indium, germanium, selenium, and tellurium. The thallium content of the flue dust is low and further enrichment steps are required. If the thallium compounds present are soluble, ie, as oxides or sulfates, direct leaching with water or dilute acid separates them from the other insoluble metals. Otherwise, the thallium compound is solubilized with oxidizing roasts, by sulfatization, or by treatment with alkaU. The thallium precipitates from these solutions as thaUium(I) chloride [7791 -12-0]. Electrolysis of the thaUium(I) sulfate [7446-18-6] solution affords thallium metal in high purity (5,6). The sulfate solution must be acidified with sulfuric acid to avoid cathodic separation of zinc and anodic deposition of thaUium(III) oxide [1314-32-5]. The metal deposited on the cathode is removed, kneaded into lumps, and dried. It is then compressed into blocks, melted under hydrogen, and cast into sticks. [Pg.467]

The traditional oxide leach plant consisted of an acid leaching step, several neutral leaching steps and, until recently, a zinc dust purification step to remove cadmium, as shown in Figure 3. In the old scheme, most of the fume and various recycle streams were leached in spent acid in the acid leach step. The resulting acid slurry was thickened, and the lead-rich solid residues were filtered, repulped in water, combined with the residue slurry from the calcine leaching plant and pumped to the smelter. [Pg.442]


See other pages where Water leach, zinc oxides is mentioned: [Pg.93]    [Pg.1035]    [Pg.254]    [Pg.4840]    [Pg.615]    [Pg.960]    [Pg.53]    [Pg.362]    [Pg.299]    [Pg.437]    [Pg.341]    [Pg.56]    [Pg.143]    [Pg.81]    [Pg.550]    [Pg.514]    [Pg.345]    [Pg.56]    [Pg.188]    [Pg.514]    [Pg.243]    [Pg.268]    [Pg.67]    [Pg.526]    [Pg.1016]    [Pg.82]    [Pg.291]    [Pg.141]    [Pg.799]    [Pg.351]    [Pg.447]    [Pg.1195]    [Pg.116]    [Pg.33]    [Pg.238]    [Pg.54]   
See also in sourсe #XX -- [ Pg.739 ]




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Leaching oxidative

Oxidant water

Oxides leaching

Water oxidation

Zinc oxide water

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