Sulfuric acid leaching of zinc silicate ore under pressure ... 01/12/2010 The results are shown in Fig. 3, which shows that the extraction of zinc and that of iron and silica increased significantly with increasing sulfuric acid concentrations and that an acid level of 0.44 mol/L is sufficient to extract more than 99% zinc and dissolve about 8.8% iron and 16.1% silica in 60 min.
The leaching of zinc silicate calcine in sulphuric acidsolutions includes a heterogeneous reaction as represented byEqs.(2) and (3).Assuming that the zinc silicate particles have aspherical geometry and the chemical reaction is the rate-controlling step, the following expression of the shrinking coremodel can be tested to describe the dissolution kinetics of theprocess:
02-02-2012· The sulfuric acid pressure leaching of zinc silicate ore is also a feasible process in that it effectively extracts most of the zinc into solution and rejects silica while providing good characteristics for solid–liquid separation.
Pressure acid leaching of zinc silicate ores selectively separates valuable zinc from silica and iron, replacing conventional pyrometallurgical and hydrometallurgical methods. This study determines the optimum conditions for the dissolution of zinc silicate concentrates and achieves a higher zinc extraction (>97%), lower iron (<0.77%) and silica dissolution (<4%) with a high ...
Leaching Behaviour of Metals from a Sphalerite Concentrate. Leaching behaviors of zinc copper indium and iron from a sphalerite concentrate in sulfuric acidoxygen system has been investigated in the present paper Various parameters were studied including particle size concentration of sulfuric acid partial pressure of oxygen leaching temperature and leaching time The experimental data ...
A solution of monosilicic acid (Si (OH) 4) was produced by leaching willemite (Zn 2 SiO 4) in sulphuric acid. Precipitation was monitored by measuring the turbidity and silica concentration in solution at regular intervals. Transmission Electron Microscopy (TEM) was used to examine the precipitate morphology. Variables known to influence silica ...
Leaching of a complex sulfidic, silicate-containing zinc ore in sulfuric acid solution under oxygen pressure Hongsheng Xu, Chang Wei⇑, Cunxiong Li, Gang Fan, Zhigan Deng, Xuejiao Zhou, Shuang Qiu Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China
A process of leaching silicated zinc ores with sulfuric acid in which the ore is reacted at elevated temperature with at least a stoichiometric amount of sulfuric acid, treating products of the reaction with a predetermined quantity of hot water, filtering the zinc sulfate solution from precipitated silica, washing with a further predetermined quantity of hot water (the total amount of hot ...
as a reductant. Batch leaching tests were carried out on zinc residue with high germanium at set pressure in stirred acid solution. The effects of SO 2, time, sulfuric acid concentration, temperature, liquid-to-solid ratio, and sulphur dioxide partial pressure on the germanium dissolution were studied to optimize the leaching parameters.
Sulfuric acid pressure leaching of zinc silicate ore was carried out to assess the effect of particle size, sulfuric acid concentration, pressure, reaction time and temperature on the extraction ...
01-12-2007· Direct silicate leaching with sulphuric acid can be represented by Eqs., for hemi-morphite and willemite, respectively. (2) Zn 4 Si 2 O 7 (OH) 2 ⋅ H 2 O + 4 H 2 SO 4 → 4 ZnSO 4 + Si 2 O (OH) 6 + 3 H 2 O (3) Zn 2 SiO 4 + 2 H 2 SO 4 → 2 ZnSO 4 + Si (OH) 4 The monosilicic acid (Si(OH) 4), produced in Eq., polymerizes and may form particles of colloidal silica (Espiari et al., 2006).
A process of leaching silicated zinc ore with sulfuric acid comprising the steps of reacting silicated zinc ore with at least a stoichiometric amount of a 1N to 6N sulfuric acid solution near its boiling point until a gelatinous mass is formed containing hydrated silica and zinc sulfate, evaporating at least 60% of the water content of the gelatinous mass so that substantially all the silica ...
Recent developments of acid leaching and solvent extraction of zinc silicate ores have produced renewed commercial interest. However, the leaching kinetics of these concentrates has received little attention. This work, therefore, addresses the leaching of a zinc silicate concentrate in sulphuric acid. The effects of particle size (0.038–0.075mm), temperature (30–50°C) and initial acid ...
Sulfuric acid pressure leaching of zinc silicate ore was carried out to assess the effect of particle size, sulfuric acid concentration, pressure, reaction time and temperature on the extraction ...
2019-2-28 · Recent developments of acid leaching and solvent extraction of zinc silicate ores have produced renewed commercial interest. However, the leaching kinetics of these concentrates has received little attention. This work, therefore, addresses the leaching of a zinc silicate concentrate in sulphuric acid.
Sulfuric acid leaching of zinc silicate ore under pressure . 1/12/2010 The obtained results show that the acid leaching of zinc silicate ore under pressure was found to be more efficient compared to other zinc hydrometallurgical process in terms of decreased dissolution of silica and iron and increased zinc extraction The most important parameter affecting the dissolution behavior of zinc ...
The kinetics of zinc silicate leaching in sodium hydroxide. zinc silicate and zinc sulphide leaching (Souza, 2007). Both routes use acid leaching to dissolve zinc from the ores/concentrates and special care is taken to avoid the formation of silica gel. This can be achieved by a stepwise addition of sulphuric acid, whereby the silicate is ...
2 · 01-12-2010· They found that neutralization, coagulation and precipitation of silicic acid with Al3+ ions ...
Short communication Sulfuric acid leaching of zinc silicate ore under pressure Hongsheng Xu, Chang Wei⁎, Cunxiong Li, Gang Fan, Zhigan Deng, Minting Li, Xingbin Li Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
A process of leaching silicated zinc ores with sulfuric acid in which the ore is reacted at elevated temperature with at least a stoichiometric amount of sulfuric acid, treating products of the reaction with a predetermined quantity of hot water, filtering the zinc sulfate solution from precipitated silica, washing with a further predetermined quantity of hot water (the total amount of hot ...
Effect of iron in zinc silicate concentrate on leaching with sulphuric acid It is well known that a series of strong acid leaching steps are required to achieve high zinc recoveries from sulphide concentrates with high- iron content due to the formation of zinc ferrites during roasting of …
01-07-2011· Based on equivalent calculations, 94.2 g/L sulfuric acid concentration is the stoichiometric amount required to leach this synthetic zinc silicate, the experimental results show that 100 g/L sulfuric acid was sufficient to extract more than 97% Zn, and no further zinc was leached with more acid.
Process of sulfuric acid leaching silicated zinc ores Download PDF Info Publication number US4070260A. US4070260A US05/656,966 US65696676A US4070260A US 4070260 A US4070260 A US 4070260A US 65696676 A US65696676 A US 65696676A US 4070260 A US4070260 A US 4070260A Authority US United States Prior art keywords zinc sulfuric acid
In recent years much emphasis has been placed on the leaching of zinc silicate ores by sulphuric acid, because these are the next best source for zinc after sulphide ores.
Sulfuric acid curing refers to the addition of concentrated sulfuric acid to heated silicates at 60–300 °C, and subsequently water leaching of the treated silicates at 30–75 °C.
sulphuric acid leaching of low grade zinc silicate ore. The results showed that decrease in particle size yielded an increase in reaction kinetics. This was due to the reduced particle radius which allowed shorter distance between the leaching reagent and the particle nucleus.