Abstract

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.

IPC Classes  ?

• C22B 3/30 - Oximes
• C22B 3/10 - Hydrochloric acid
• C22B 3/28 - Amines
• C22B 23/00 - Obtaining nickel or cobalt

Abstract

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.

IPC Classes  ?

• C22B 3/10 - Hydrochloric acid
• C22B 3/22 - Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means
• C22B 3/26 - Treatment or purification of solutions, e.g. obtained by leaching by liquid-liquid extraction using organic compounds
• C22B 34/12 - Obtaining titanium

Abstract

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.

IPC Classes  ?

• C22B 3/10 - Hydrochloric acid
• C22B 3/24 - Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means by adsorption on solid substances, e.g. by extraction with solid resins
• C22B 3/30 - Oximes
• C22B 3/44 - Treatment or purification of solutions, e.g. obtained by leaching by chemical processes
• C22B 11/00 - Obtaining noble metals

Abstract

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.

IPC Classes  ?

• C22B 3/10 - Hydrochloric acid
• C22B 3/24 - Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means by adsorption on solid substances, e.g. by extraction with solid resins
• C22B 3/26 - Treatment or purification of solutions, e.g. obtained by leaching by liquid-liquid extraction using organic compounds
• C22B 3/44 - Treatment or purification of solutions, e.g. obtained by leaching by chemical processes
• C22B 59/00 - Obtaining rare earth metals

Abstract

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.

IPC Classes  ?

• C22B 3/10 - Hydrochloric acid
• C22B 3/22 - Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means
• C22B 3/26 - Treatment or purification of solutions, e.g. obtained by leaching by liquid-liquid extraction using organic compounds
• C22B 23/00 - Obtaining nickel or cobalt
• C22B 61/00 - Obtaining metals not elsewhere provided for in this subclass

Abstract

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).

IPC Classes  ?

• C01B 33/023 - Preparation by reduction of silica or silica-containing material
• C22B 3/06 - Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions