Abrégé

The invention provides a process for the leaching of a laterite ore or concentrate for the recovery of value metals, at least one value metal being nickel. The laterite ore or concentrate is subjected to a leaching step in acidic mixed chloride solution to leach nickel from the laterite ore. Nickel is extracted with an oxime at a lower pH than other processes for extraction of nickel from solution, especially after separation of iron and cobalt values.

Classes IPC  ?

• C22B 3/30 - Oximes
• C22B 3/10 - Acide chlorhydrique
• C22B 3/28 - Amines
• C22B 23/00 - Obtention du nickel ou du cobalt

Abrégé

A process for leaching a value metal from a titaniferous ore material comprising the step of leaching the ore material at atmospheric pressure with a lixiviant comprising magnesium chloride and hydrochloric acid is disclosed. Iron and titanium are leached into solution. Iron in the ferric state may be separated from titanium in solution using extraction with alkyl ketone. More effective separation of titanium with lower contamination with iron is obtained.

Classes IPC  ?

• C22B 3/10 - Acide chlorhydrique
• C22B 3/22 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par des procédés physiques, p. ex. par filtration, par des moyens magnétiques
• C22B 3/26 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par extraction liquide-liquide utilisant des composés organiques
• C22B 34/12 - Obtention du titane

Abrégé

A process for the extraction of gold from a gold-bearing ore or concentrate, comprising the steps of leaching the gold-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of at least 90°C and an Eh of at least 900 mV. After a liquid/solids separation step, the solution obtained is subjected to an organic solvent extraction step using an oxime to obtain a solution of organic solvent containing gold, which is stripped with sodium thiosulphate to recover gold. The extraction may be operated to extract gold with or without iron. Materials used in the process may be recycled. The process avoids environmental and other hazards associated with the use of cyanide to extract gold.

Classes IPC  ?

• C22B 3/10 - Acide chlorhydrique
• C22B 3/24 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par des procédés physiques, p. ex. par filtration, par des moyens magnétiques par adsorption sur des substances solides, p. ex. par extraction avec des résines solides
• C22B 3/30 - Oximes
• C22B 3/44 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par des procédés chimiques
• C22B 11/00 - Obtention des métaux nobles

Abrégé

A process for the extraction of rare earth elements, including yttrium, from a rare earth element-bearing ore or concentrate, comprising the steps of leaching the rare earth element-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of from 90°C to the boiling point of the solution and at an Eh of at least 200 mV. After a liquid/solids separation step, the solution obtained is subjected to steps for removal of iron and for recovery of rare earth elements. Alternatively, rare earth element-bearing ore or concentrate may be leached with sulphuric acid and liquid obtained subjected to extraction of iron and other impurities. Raffinate obtained may be treated with oxalic acid, the precipitate dissolved in hydrochloric acid and subjected to solvent extraction for rare earth elements or the raffinate may be subjected to solvent extraction for removal of rare earth elements and then stripped with hydrochloric acid.

Classes IPC  ?

• C22B 3/10 - Acide chlorhydrique
• C22B 3/24 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par des procédés physiques, p. ex. par filtration, par des moyens magnétiques par adsorption sur des substances solides, p. ex. par extraction avec des résines solides
• C22B 3/26 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par extraction liquide-liquide utilisant des composés organiques
• C22B 3/44 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par des procédés chimiques
• C22B 59/00 - Obtention des métaux des terres rares

Abrégé

The invention provides a process for the leaching of a laterite ore, concentrate, tailings or waste rock for the recovery of value metals, at least one value metal being nickel. The laterite ore or concentrate is subjected to a leaching step with a lixiviant comprising hydrochloric acid to leach nickel from the laterite ore, followed by a liquid/solids separation step. The liquid obtained is subject to solvent extraction with a dialkyl ketone, to obtain a solution rich in iron and a raffinate. Separation of iron from cobalt and nickel is obtained.

Classes IPC  ?

• C22B 3/10 - Acide chlorhydrique
• C22B 3/22 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par des procédés physiques, p. ex. par filtration, par des moyens magnétiques
• C22B 3/26 - Traitement ou purification de solutions, p. ex. de solutions obtenues par lixiviation par extraction liquide-liquide utilisant des composés organiques
• C22B 23/00 - Obtention du nickel ou du cobalt
• C22B 61/00 - Obtention des métaux non prévus ailleurs dans la présente sous-classe

Abrégé

A process to the production of silicon from amorphous silica is disclosed. The amorphous silica is formed from a material rich in silica, especially rice husk ash or silica fume. The process comprises subjecting the amorphous silica to leaching with a lixiviant of aqueous mineral acid, especially hydrochloric acid. Preferably, material rich in silica is roasted at a temperature of not more than 850°C, subjected to leaching and then subjected to a second roasting at a temperature of less than 750°C. The process provides for the production of high purity silicon, especially to the production of solar grade silicon (SoG-Si).

Classes IPC  ?

• C01B 33/023 - Préparation par réduction de silice ou d'un matériau contenant de la silice
• C22B 3/06 - Extraction de composés métalliques par voie humide à partir de minerais ou de concentrés par lixiviation dans des solutions inorganiques acides