The present invention discloses a process for recovering ammonia from vanadium preparation for ammonium preparation and recycling wastewater. A conventional vanadium extraction process is complex, and the most difficult to control and treat are ammonia emissions and wastewater treatment. The present process can directly extract ammonium metavanadate and ammonium polyvanadate from the beginning of mining and smelting, and gather all emitted ammonia to prepare ammonium in the process of preparing high-purity vanadium pentoxide by using the ammonium metavanadate or the ammonium polyvanadate, thereby ensuring zero emission of the exhaust gas, and effectively treat all wastewater generated in the above process by using a polyacid ester folucculation technology, thereby ensuring that the wastewater is not discharged but recycled, and realizing that the purity of all products reaches 99.5-99.99%.

The present disclosure relates to a process for recovering vanadium in the form of iron vanadate from a gasifier slag. The process comprises pulverizing the slag to obtain pulverized slag (2). The pulverized slag (2) is soaked in water (6) and an alkali salt (4) to obtain a slurry (8), followed by roasting the slurry in the presence of air to obtain roasted slag (12) which is leached (14) to obtain a first solution (18). The first solution (18) is heated at a temperature in the range of 60 C. to 80 C. while adding an iron salt (17) in an amount in the range of 10 wt % to 60 wt % at a pH in the range of 4 to 10, to obtain a second solid residue (21) which is dried to obtain iron vanadate (24).

The present disclosure relates to a process for recovering vanadium in the form of iron vanadate from a gasifier slag. The process comprises pulverizing the slag to obtain pulverized slag (2). The pulverized slag (2) is soaked in water (6) and an alkali salt (4) to obtain a slurry (8), followed by roasting the slurry in the presence of air to obtain roasted slag (12) which is leached (14) to obtain a first solution (18). The first solution (18) is heated at a temperature in the range of 60 C. to 80 C. while adding an iron salt (17) in an amount in the range of 10 wt % to 60 wt % at a pH in the range of 4 to 10, to obtain a second solid residue (21) which is dried to obtain iron vanadate (24).

A system for extracting vanadium from a leaching solution containing vanadium chromium silicon and for preparing vanadium pentoxide, and a method therefor, the system comprising, in sequence: an impurity removal system, an extraction system, a reverse-extraction and vanadium precipitation system, a washing system and a calcining system. The method comprises the following steps: removing silicon in a leaching solution by using a silicon removal agent, extracting most of the vanadium to an organic phase by using centrifugal extraction, reverse-extracting the vanadium of a vanadium-rich organic phase by using a mixed solution containing a basic solution and an ammonium salt, and precipitating ammonium metavanadate to obtain an ammonium metavanadate solid, washing and drying, and then calcining at a certain temperature to obtain a low chromium, low silicon, low aluminum and high-purity vanadium pentoxide product.

A system for extracting vanadium from a leaching solution containing vanadium chromium silicon and for preparing vanadium pentoxide, and a method therefor, the system comprising, in sequence: an impurity removal system, an extraction system, a reverse-extraction and vanadium precipitation system, a washing system and a calcining system. The method comprises the following steps: removing silicon in a leaching solution by using a silicon removal agent, extracting most of the vanadium to an organic phase by using centrifugal extraction, reverse-extracting the vanadium of a vanadium-rich organic phase by using a mixed solution containing a basic solution and an ammonium salt, and precipitating ammonium metavanadate to obtain an ammonium metavanadate solid, washing and drying, and then calcining at a certain temperature to obtain a low chromium, low silicon, low aluminum and high-purity vanadium pentoxide product.

A vanadium recovery approach utilizes oil fly ash (OFA), in contrast to coal fly ash, for separation and recovery of vanadium. OFA is first carbon burned to reduce the volume for recycling, and also to provide a fuel for other industrial processes. Following an almost 90% weight reduction from carbon burning, the remaining material includes about 18% vanadium. A salt roasting performed at the same temperature (about 650 C.) as the carbon burning allows use of the same oven or furnace, reducing heat requirements for the overall process. Salt roasting generates a water-soluble material from which a water leaching process yields a vanadium leach solution containing recovered vanadium, avoiding a need for caustic or volatile leaching agents. Ammonium metavanadate is precipitated from the vanadium leach solution through addition of ammonium sulfate, and a calcination process used to generate vanadium oxide (V.sub.2O.sub.5).

A vanadium recovery approach utilizes oil fly ash (OFA), in contrast to coal fly ash, for separation and recovery of vanadium. OFA is first carbon burned to reduce the volume for recycling, and also to provide a fuel for other industrial processes. Following an almost 90% weight reduction from carbon burning, the remaining material includes about 18% vanadium. A salt roasting performed at the same temperature (about 650 C.) as the carbon burning allows use of the same oven or furnace, reducing heat requirements for the overall process. Salt roasting generates a water-soluble material from which a water leaching process yields a vanadium leach solution containing recovered vanadium, avoiding a need for caustic or volatile leaching agents. Ammonium metavanadate is precipitated from the vanadium leach solution through addition of ammonium sulfate, and a calcination process used to generate vanadium oxide (V.sub.2O.sub.5).

The invention provides a method for the recovery of a metal-containing product (M.sub.Prod) comprising: providing a composite material comprising a matrix of oxidised reductant (R.sub.o), a product metal (M.sub.P) dispersed in the matrix of oxidised reductant (R.sub.o), and one or more metal compounds (M.sub.PC.sub.R) of the product metal (M.sub.P) in one or more oxidation states dispersed in the matrix of oxidised reductant (R.sub.o); and treating the composite material to at least partially remove the one or more metal compounds (M.sub.PC.sub.R) from the matrix of oxidised reductant (Ro) to form the metal-containing product (M.sub.Prod).

The invention provides a method for the recovery of a metal-containing product (M.sub.Prod) comprising: providing a composite material comprising a matrix of oxidised reductant (R.sub.o), a product metal (M.sub.P) dispersed in the matrix of oxidised reductant (R.sub.o), and one or more metal compounds (M.sub.PC.sub.R) of the product metal (M.sub.P) in one or more oxidation states dispersed in the matrix of oxidised reductant (R.sub.o); and treating the composite material to at least partially remove the one or more metal compounds (M.sub.PC.sub.R) from the matrix of oxidised reductant (Ro) to form the metal-containing product (M.sub.Prod).

An object of the present invention is to recover a minor metal and/or rare-earth metal.

The present invention provides a method for recovering a minor metal and/or rare-earth metal from a post-chlorination residue in titanium smelting.

The minor metal and/or rare-earth metal is one or more metal selected from the group consisting of Sc, V, Nb, Zr, Y, La, Ce, Pr, and Nd.