Manganese ores are a type of minerals , natural mineral formations, in which the manganese content is sufficient for the cost-effective extraction of this metal or its compounds. The most important ore-forming minerals include: pyrolyusite MnO 2 · Н 2 О (63.2% Mn), psilomelan mMnO · MnO 2 · nH 2 O (45-60% Mn), manganite MnO · Mn (OH) 2 (62, 5% Mn), vernadite MnO 2 · H 2 O (44-52% Mn), brownite Mn 2 O 3 (69.5% Mn), Hausmanite Mn 3 O 4 (72% Mn), rhodochrosite MnCO 3 (47, 8% Mn), oligonite (Mn, Fe) CO 3 (23–32% Mn), manganocalcite (Ca, Mn) CO 3 (up to 20–25% Mn), rhodonite (Mn, Ca) (Si 3 O 9 ) (32–41% Mn), bustamite (Ca, Mn) (Si 3 O 9 ) (12–20% Mn).
Content
- 1 Classification
- 1.1 Types of Manganese Ore
- 1.2 Types of ore deposits by genesis
- 2 Origin (Genesis)
- 3 Distribution
- 4 Mining and processing of ores
- 5 Use
- 6 See also
- 7 Literature
- 8 References
Classification
Types of Manganese Ore
- Oxide
- Carbonate
- Oxide Carbonate
The main industrial ores are oxide ores. They are represented by pyrolyusite, psilomelan, cryptomelan, mangant, hausmanite, brownite, holondite, coronadite, bixbitite, nsuitite, bernesite, Todorokite, etc.
Types of ore deposits by genesis
1) Sedimentary
- a) sedimentary
- b) volcanic-sedimentary
2) Volcanogenic
3) Metamorphosed
4) Deposits of weathering crust
Origin ( Genesis )
Manganese ore deposits are found on all continents. Iron manganese is almost always present in manganese ores. In terms of genesis, sedimentary deposits, represented by stratum and lenticular deposits formed in ancient marine or lake basins (Nikopol deposit in Ukraine and Chiatur deposit in Georgia, Polunochnoe (carbonate manganese ore) in the Urals, deposits of Morocco, are of the greatest importance. These ores are of the greatest industrial importance. Among them, the following main types are distinguished:
a) oxide psilomelano-pyrolusite and manganite ores formed at a shallow depth, in the zone of maximum saturation of water with dissolved oxygen; Mn content in individual deposits is 19–36%;
b) carbonate , mainly rhodochrosite, oligonite, manganese-calcite ores that form at great depths, under conditions of oxygen deficiency accompanied by hydrogen sulfide fermentation; Mn content from 16 to 25%, differ from oxide ores in high phosphorus content.
Metamorphic deposits are formed due to changes in sedimentary deposits in the bowels of the Earth under the influence of high temperatures and pressures ( Usinskoye in Western Siberia , deposits of the Atasuysky district in Central Kazakhstan ); usually represented by dense varieties of ores, in which anhydrous oxides ( brownite , gausmanite ) and manganese silicates ( rhodonite and others) take part; Among them, iron-manganese ores with a Mn content of about 10% are developed, including industrial concentrations of Fe minerals ( magnetite , hematite and others).
The weathering deposits are represented by powerful ancient and modern weathering crusts with a secondary concentration of manganese in them (deposits of India , Brazil , Ghana , South Africa ); these are loose oxidized ores of the so-called manganese hats, composed of pyrolyusite , psilomelan and other hydroxides of manganese and iron. which is not correct.
Ferromanganese nodules At the bottom of modern oceans are clusters of iron-manganese nodules, which constitute large resources of manganese ores. The mineral composition of nodules is dominated by hydroxides of manganese ( Todorokite , Burnessite , Buserite , Asbolan ) and iron ( vernadite , hematite ), all metals of economic interest are associated with them. The chemical composition of ocean nodules is extremely diverse: in varying amounts, almost all elements of the periodic table are present.
Initial information about ore formations at the bottom of the ocean was obtained during the first integrated oceanological expedition in the history of world science on the English ship Challenger, which lasted almost four years (1872-1876). On February 18, 1873, when dredging was carried out 160 miles southwest of the Canary Islands , black rounded nodules were raised from the bottom - ferromanganese nodules containing, as already shown by the first analyzes, a significant amount of manganese, nickel , copper and cobalt . True, somewhat earlier, in 1868, during the expedition of N. Nordenskjöld to the Swedish ship Sofia, similar nodules were lifted from the bottom of the Kara Sea , but this finding remained almost unnoticed.
Distribution
| Dislocation | The main type of deposits | Industrial reserves,% | Production, thousand tons | Mn Content |
|---|---|---|---|---|
| Gabon | Weathering bark | 4.7 | 2 460 | 30-50% |
| South Africa | Volcanogenic sedimentary | 19.9 | 2,200 | 38-50% |
| Australia | Weathering bark | 3,5 | 1,340 | 30-50% |
| Brazil | Weathering bark | 1,300 | 10-20% | |
| China | 2,8 | 900 | ||
| Ukraine | Sedimentary | 42,2 | 720 | 8-34% |
| India | Metamorphosed | 640 | 10-20% | |
| Ghana | 559 | |||
| Kazakhstan | Volcanogenic sedimentary | 7.3 | 183 | |
| Mexico | 136 |
World reserves of manganese ores are represented by 90% oxide (38%) and oxide-carbonate (52%) ores.
In South Africa, about 95% of the reserves are concentrated in the unique manganese-iron ore zone of Kuruman , the largest deposits are Mamatwan (average manganese content 38%), Wessels (47%) Middelplatz (36%)
In China , manganese reserves are represented by small but numerous oxide ore deposits. The average ore content is 20-40%. The country is constantly searching and exploring new deposits of manganese in order to weaken the country's dependence on imports of high-quality ores.
In Kazakhstan, more than 90% is located in the Central Kazakhstan region, in the Karazhal and Ushkatyn deposits . Reserves of about 85 million tons (average manganese content of 22%).
Deposits of Ukraine are located in the South Ukrainian manganese ore basin. These are deposits of the Nikopol group and the Bolshetokmakskoye containing 33 and 67% of the confirmed reserves of Ukraine. Ukraine also has one of the most powerful ore processing and manganese ferroalloy complexes in Europe, including the Nikopol, Zaporizhzhya and Stakhanovsky plants.
In Georgia, the main raw material base is the Chiaturskoye field . Oxide ores make up 28% (average manganese content 26%) of confirmed reserves, carbonate ores (average manganese content 18% -72%).
In Russia, manganese is an extremely scarce raw material of strategic importance. In addition to the indicated Usinsky and Midnight deposits, the Yuzhno-Khingansky Maly Khingans in the Jewish Region , Porozhinsky on the Yenisei Ridge, Rogachevo-Taininsky area (260 million tons of carbonate ores, with a grade of 8-15%) and the underexplored Severo-Taininsky ore field (5 million tons of oxide ores, with a content of 16-24%) on Novaya Zemlya .
Mining and processing ores
Manganese ore is mined predominantly through open pit mining using highly productive excavators. Enrichment - by gravitational, gravitational magnetic methods and flotation. The resulting manganese ore concentrates are sorted according to grades depending on the manganese content, higher grades contain 45-49%. Total world production is 20–25 million tons per year (for 1990 ), and reserves are 15 billion tons (for 1998 ).
Usage
Manganese ores are divided into chemical and metallurgical. The former contain at least 80% MnO 2 . They are used in galvanic cells , in the production of glass , ceramics , mineral dyes , and potassium permanganate (KMnO 4 ). Ores containing less than 80% pyrolusite are called metallurgical and are used in ferrous metallurgy . Manganese in the form of alloys with iron ( ferromanganese ) and silicon ( silicomanganese ) is used for the production of rail and structural steel , alloys based on aluminum , magnesium and copper are alloyed with it .
See also
- Manganese
- Manganese ore industry
- Nikopol manganese ore pool
Literature
- GNPP Cartography , 2006
- Small Mining Encyclopedia, 2004