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 Production: The roast-leach-electrowin process for zinc production involves roasting zinc sulphide concentrate to produce calcine containing zinc oxide. The resultant leach liquor contains up to 30 g/L of iron, which is subsequently precipitated by hydrolysis as ammonium jarosite [NH4Fe3(SO4)2OH6].

Where does jarosite come from?

This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides. Jarosite is often produced as a byproduct during the purification and refining of zinc and is also commonly associated with acid mine drainage and acid sulfate soil environments.

Where is jarosite mineral found?

Antarctica
Jarosite has been found in the ice cores that were extracted from Antarctica by a team of international researchers recently.

Why is jarosite waste hazardous?

Jarosite released from zinc metal extraction process is hazardous in nature and its world wide disposal has become a major environmental concern. Jarosite contain higher concentration of toxic elements (lead, zinc, sulphur, cadmium, chromium and copper) than that of CCRs.

Is jarosite a sulfate?

Mineral Description Jarosite is a potassium iron sulfate mineral of composition KFe3(SO4)2(OH)6 usually derived from the oxidation of pyrite and other Fe-bearing sulfides.

Is pyrite worth any money?

Famous for raising hopes of riches beyond imagination—and then dashing them—the mineral pyrite is better known as fool’s gold. It may be worthless as a currency, but that doesn’t mean pyrite doesn’t have value—or at least the potential for it.

What is pyrite disease?

When exposed to humid air, pyrite reacts with oxygen and water to create iron sulfide (the rust), corrosive sulfuric acid and harmful sulfur dioxide gas. This chemical reaction, called pyrite disease, causes specimens to crack and crumble. Left unchecked, pyrite disease eventually destroys a specimen.

Is pyrrhotite a rock or mineral?

iron sulfide mineral
Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic.

What does pyrrhotite do to concrete?

Pyrrhotite, a mineral of concern for the construction industry, consists of iron and sulfur, and when exposed to water and air, it can break down to form secondary minerals that expand and crack concrete, causing concrete structures, like home foundations, to fail.

What is jarosite made of?

The jarosite waste is mixed with ferrous slag and another industrial waste containing zinc, lead, iron, manganese, chromium, and copper in percentage range 0.5-1.6 and cadmium 0.13 %. The mixture is compressed at 10 Mpa for one minute, The compacted mixtures are then hardened at 98 % humidity for 60-90 days.

What is the pH of Jarosite?

The jarosite pulp is thickened and then neutralised at a pH of approximately 4.0, by the addition of a ferric hydroxide/gypsum precipitate and ammonia. The neutralised jarosite is filtered and extensively washed on the filter before discharge in order to remove entrained zinc plant liquor.

What is the chemical formula for jarjarosite?

Jarosite is a basic hydrous sulfate of potassium and iron with a chemical formula of KFe3+3(OH)6(SO4)2.

Where can jarjarosites be found?

Jarosites are most commonly encountered in low-pH, high-ferric iron/ sulfate-containing liquors that also contain significant concentrations of basic metal cations, such as process waters at biomining sites as well as mine-waste sites and mine waters (e.g., at Iron Mountain, California;