A method for the recovery of vanadium from a vanadium containing feed stream, the method comprising the steps of: subjecting the vanadium feed stream to a leach step, the leach step comprising contacting the vanadium feed stream with an alkaline carbonate leach solution to form a leach slurry comprising a pregnant leach solution containing vanadium and a solid residue; passing the leach slurry to a solid/liquid separation step to produce a pregnant leach solution containing vanadium; and recovering a vanadium product from the pregnant leach solution.

A method for the recovery of vanadium from a vanadium containing feed stream, the method comprising the steps of: subjecting the vanadium feed stream to a leach step, the leach step comprising contacting the vanadium feed stream with an alkaline carbonate leach solution to form a leach slurry comprising a pregnant leach solution containing vanadium and a solid residue; passing the leach slurry to a solid/liquid separation step to produce a pregnant leach solution containing vanadium; and recovering a vanadium product from the pregnant leach solution.

Various embodiments provide a leaching solution monitoring module comprising a first leaching solution distribution system interface, a flow meter in fluid communication with the first leaching solution distribution system interface, the flow meter in fluid communication a 3-way pressure regulator, and a second leaching solution distribution system interface in fluid communication with the 3-way pressure regulator.

A method for extracting scandium from scandium-containing materials, said method comprising: re-slurring of a cake of a scandium-containing material with a mixture of sodium carbonate and sodium bicarbonate, carbonization leaching of the scandium-containing material with the mixture of sodium carbonate and sodium bicarbonate in one stage, filtration of the leached scandium-containing material and the precipitation of a scandium concentrate. The carbonization leaching of the scandium-containing material is carried out with a mixture of sodium carbonate and sodium bicarbonate having a Na2CO3 concentration of 130-350 g/dm.sup.3 and a NaHCO3 concentration of 2-100 g/dm.sup.3 at a pH value in the slurry of 9.5-11.0 and a temperature of 20-90° C. For maintaining the required pH value in the slurry, the slurry is gassed with a CO2-containing gas-air mixture. The scandium concentrate is extracted from the filtrate resulting from the leaching process in one stage by treating said filtrate with an alkaline solution.

A method for extracting scandium from scandium-containing materials, said method comprising: re-slurring of a cake of a scandium-containing material with a mixture of sodium carbonate and sodium bicarbonate, carbonization leaching of the scandium-containing material with the mixture of sodium carbonate and sodium bicarbonate in one stage, filtration of the leached scandium-containing material and the precipitation of a scandium concentrate. The carbonization leaching of the scandium-containing material is carried out with a mixture of sodium carbonate and sodium bicarbonate having a Na2CO3 concentration of 130-350 g/dm.sup.3 and a NaHCO3 concentration of 2-100 g/dm.sup.3 at a pH value in the slurry of 9.5-11.0 and a temperature of 20-90° C. For maintaining the required pH value in the slurry, the slurry is gassed with a CO2-containing gas-air mixture. The scandium concentrate is extracted from the filtrate resulting from the leaching process in one stage by treating said filtrate with an alkaline solution.

A method of separating and recovering a cobalt salt and a nickel salt includes a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least both the cobalt salt and the nickel salt as rare metals, in which the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25° C., individually permeate through the nanofiltration membrane at an operating pressure of 0.5 MPa.

A method of separating and recovering a cobalt salt and a nickel salt includes a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least both the cobalt salt and the nickel salt as rare metals, in which the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25° C., individually permeate through the nanofiltration membrane at an operating pressure of 0.5 MPa.

A process for recovering titanium dioxide from a titanium-bearing material, the process including the steps of: leaching the titanium-bearing material in a first leaching step at atmospheric pressure and at a temperature of 70 to 97° C. with a first lixiviant to produce a first leach solution comprising undissolved first leach solids that include a titanium content and a first leach liquor, the first lixiviant comprising hydrochloric acid at a concentration of less than 23% w/w; separating the first leach liquor and the undissolved first leach solids; leaching the first leach solids in a second leaching step at atmospheric pressure and at a temperature of 60 to 80° C. with a second lixiviant in the presence of a Fe powder reductant to produce a second leach solution comprising undissolved second each solids and a second leach liquor that includes a leached titanium content and iron content, the second lixiviant comprising a mixed chloride solution comprising less than 23% w/w hydrochloric acid and an additional chloride selected from alkali metal chlorides, magnesium chloride and calcium chloride, or mixtures thereof; separating the second leach liquor and the undissolved second leach solids; and thereafter separating the titanium dioxide and the iron content from the second leach liquor by precipitation, and regenerating the second lixiviant for recycle to the second leaching step.

A process for recovering titanium dioxide from a titanium-bearing material, the process including the steps of: leaching the titanium-bearing material in a first leaching step at atmospheric pressure and at a temperature of 70 to 97° C. with a first lixiviant to produce a first leach solution comprising undissolved first leach solids that include a titanium content and a first leach liquor, the first lixiviant comprising hydrochloric acid at a concentration of less than 23% w/w; separating the first leach liquor and the undissolved first leach solids; leaching the first leach solids in a second leaching step at atmospheric pressure and at a temperature of 60 to 80° C. with a second lixiviant in the presence of a Fe powder reductant to produce a second leach solution comprising undissolved second each solids and a second leach liquor that includes a leached titanium content and iron content, the second lixiviant comprising a mixed chloride solution comprising less than 23% w/w hydrochloric acid and an additional chloride selected from alkali metal chlorides, magnesium chloride and calcium chloride, or mixtures thereof; separating the second leach liquor and the undissolved second leach solids; and thereafter separating the titanium dioxide and the iron content from the second leach liquor by precipitation, and regenerating the second lixiviant for recycle to the second leaching step.

A mineral processing method capable of efficiently separating a copper mineral from a molybdenum mineral is provided. The mineral processing method includes: a conditioning step of adding sulfite as a surface treatment agent to a mineral slurry containing a copper mineral and a molybdenum mineral; and a flotation step of performing flotation using the mineral slurry after the conditioning step. The hydrophilicity of the copper mineral can be selectively enhanced by sulfite, so as to be able to produce a difference in hydrophilicity between the copper mineral and the molybdenum mineral. Therefore, the molybdenum mineral can be selectively caused to float, and the copper mineral and the molybdenum mineral can be efficiently separated from each other.