What is jarosite precipitation?
Abstract. Jarosite is a family of iron-hydroxysulphate minerals that commonly occur in acidic, sulfate-rich environments, and mining and ore processing wastes. Jarosite precipitation is used in hydrometallurgy, especially the zinc industry, to control iron, sulfate and other impurities.
What is jarosite process?
Jarosite residues come from jarosite process in traditional zinc hydrometallurgy [1], [2]. When zinc calcine is leached with strong acid at high temperature a leaching solution with high iron is produced. Zinc hydrometallurgy provides for more than 85% weight of zinc in the world every year [2].
How do you identify jarosite?
Jarosite has a trigonal crystal structure and is brittle, with basal cleavage, a hardness of 2.5-3.5, and a specific gravity of 3.15-3.26. It is translucent to opaque with a vitreous to dull luster, and is colored dark yellow to yellowish-brown.
Where can jarosite be found?
Jarosite has been found in the ice cores that were extracted from Antarctica by a team of international researchers recently.
Where is Ferrihydrite found?
On Earth, ferrihydrite is found in many surface and near-surface environments, including cold and hot springs, fresh and acid sulfate waters, lacustrine and marine sediments, and various types of soils [Chukhrov et al., 1972; Schwertmann and Fischer, 1973; Carlson and Schwertmann, 1981; Tipping et al., 1981; Eggleton.
How is ferrihydrite formed?
In the natural environment ferrihydrite often forms by oxidation of Fe(II)aq at near neutral pH,(1) and under these conditions Fe13, if formed, would be expected to be highly transitory. In acidic conditions, such as in acid mine runoff, Fe13 may be more persistent.
Is ferrihydrite magnetic?
These observations suggest that ferrihydrite is a potential magnetic remanence carrier under ambient environmental conditions. Measurements of mineral mixtures show that magnetic techniques can discriminate between ferrihydrite and goethite at low concentrations.
What is the formula of Anglesite?
| Anglesite | |
|---|---|
| Category | Sulfate minerals |
| Formula (repeating unit) | PbSO4 |
| Strunz classification | 7.AD.35 |
| Dana classification | 28.3.1.3 |
Is Ferrihydrite magnetic?
What is the chemical composition of goethite?
Goethite (Fe(OH)O)
| PubChem CID | 91502 |
|---|---|
| Molecular Formula | FeO2H or FeHO2 |
| Synonyms | hydroxy(oxo)iron Lepidocrocite Goethite (Fe(OH)O) Iron hydroxide oxide (Fe(OH)O) Iron(III) oxide-hydroxide More… |
| Molecular Weight | 88.85 |
| Dates | Modify 2021-08-21 Create 2005-08-08 |
What are the physical properties of a jarosite?
Physical properties. Jarosite has a trigonal crystal structure and is brittle, with basal cleavage, a hardness of 2.5-3.5, and a specific gravity of 3.15-3.26.
What happens to the zinc in jarosite precipitation?
Zinc loss in jarosite residue is limited. The process generates jarosite that contains 30% iron in large quantity, which is an unusable slag and has to be solidified and landfilled at high cost, a challenge to environment and sustainable development. What’s more, jarosite precipitation also takes away valuable metals like In, Ga, Ge and etc ..
Which is better, goethite precipitation or jarosite precipitation?
Goethite precipitation is superior as the residue amount is only 50% of that by jarosite precipitation. On one hand, the precious metal In, Ge, Ge can be enriched and precipitated before iron removal. On the other hand, the goethite residue can be sold as material for cement production instead of landfilled as hazardous waste. 3.
Which is the optimum temperature for the dissolution of Jarosite?
Increasing acid concentration favors the dissolution of jarosite, but it reverses the hematite precipitation reaction and tends to form basic iron sulfate, which generates considerably less acid: Optimum temperature for decomposition is 225 °C. The precipitation of hematite is facilitated by seeding with a crystal of hematite.
