bauxite through mining into alumina in jamaica

Bauxite Mining and Alumina Production in Jamaica

Jamaica is one of the world’s leading producers of bauxite, the primary ore used to produce alumina (aluminum oxide, Al₂O₃), which is then refined into aluminum. Here’s an overview of the process from mining to alumina production in Jamaica:

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1. Bauxite Mining in Jamaica
– Location: Major bauxite deposits are found in St. Ann, Manchester, Clarendon, and St. Elizabeth.
– Mining Method: Open-pit mining is commonly used because bauxite deposits are near the surface.
– Companies Involved:
– Noranda Jamaica Bauxite Partners (New Day Aluminum) – St. Ann
– Jamalco (Joint venture between Century Aluminum and the Jamaican government) – Clarendon
– Windalco (owned by UC Rusal) – St. Ann & Manchester

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2. Processing Bauxite into Alumina
Once mined, bauxite is refined into alumina through the Bayer Process:

# (A) Crushing & Grinding
– Bauxite ore is crushed and ground into a fine powder to increase surface area for chemical processing.

# (B) Digestion (Chemical Leaching)
– The powdered bauxite is mixed with a hot sodium hydroxide (NaOH) solution under high pressure and temperature (~150°C).
– This dissolves the aluminum hydroxide (Al(OH)₃), leaving impurities like iron oxides and silica as “red mud” waste.

# (C) Clarification & Filtration
– The liquid sodium aluminate solution is separated from the insoluble red mud through settling and filtration.

# (D) Precipitation
– The filtered solution is cod, and pure aluminum hydroxide crystals are precipitated out by seeding with fine alumina particles.

# (E) Calcination (Heating to Form Alumina)
– The aluminum hydroxide is heated at ~1000°C in rotary kilns to remove water, producing anhydrous alumina (Al₂O₃).

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3. Alumina Refineries in Jamaica
Jamaica has two major alumina refineries:
1. Jamalco Refinery (Clarendon) – Capacity: ~1.4 million tonnes/year.
2. Windalco Refineries (Ewarton & Kirkvine) – Combined