公开(公告)号：US20190177178A1

公开(公告)日：2019-06-13

申请号：US16213243

申请日：2018-12-07

Applicant: Worcester Polytechnic Institute

Inventor： Sumedh Gostu ,  Brajendra Mishra

IPC: C01G49/08 ,  C22B3/16 ,  C07F15/02

Abstract: A low-temperature leaching operation employs a raw, red mud slurry directly from aluminum production for an oxalic acid leaching of ferric oxalate. Residual calcium, titanium, aluminum and other rare earths are also recoverable in a secondary stream. Monitoring and control of the pH of the leach solution yields soluble ferric oxalate without high temperatures or specific radiation or light sources. Addition of iron powder results in precipitation of ferrous oxalate, isolated by magnetic separation from the iron powder which recirculates in the solution. Magnetite may then be produced by heating the ferrous oxalate in low pO2 conditions.

公开(公告)号：US12049409B2

公开(公告)日：2024-07-30

申请号：US17547557

申请日：2021-12-10

Applicant: Worcester Polytechnic Institute

Inventor： Himanshu Tanvar ,  Brajendra Mishra

IPC: C01F7/0653 ,  C01F7/066

CPC classification number: C01F7/0653 ,  C01F7/066

Abstract: Bauxite residue recovery includes mixing a solution of hydrochloric acid (HCL) according to a predetermined concentration, and adding the HCL solution to a quantity of raw red mud recovered from industrial operations as waste material. The highly alkaline property of the bauxite residue, commonly known as red mud is at least partially neutralized from the HCL, and makes the resulting washed red mud more amenable to subsequent uses in various applications in fields such as construction, wastewater treatment, and metal recovery processes. The process recovers washed red mud from the red mud and HCL solution by filtering the raw red mud and HCL solution for generating a stream of leach liquor from the filtrate and the recovered washed red mud from the residue.

公开(公告)号：US20220185688A1

公开(公告)日：2022-06-16

申请号：US17547557

申请日：2021-12-10

Applicant: Worcester Polytechnic Institute

Inventor： Himanshu Tanvar ,  Brajendra Mishra

IPC: C01F7/0653 ,  C01F7/066

Abstract: Bauxite residue recovery includes mixing a solution of hydrochloric acid (HCL) according to a predetermined concentration, and adding the HCL solution to a quantity of raw red mud recovered from industrial operations as waste material. The highly alkaline property of the bauxite residue, commonly known as red mud is at least partially neutralized from the HCL, and makes the resulting washed red mud more amenable to subsequent uses in various applications in fields such as construction, wastewater treatment, and metal recovery processes. The process recovers washed red mud from the red mud and HCL solution by filtering the raw red mud and HCL solution for generating a stream of leach liquor from the filtrate and the recovered washed red mud from the residue.

公开(公告)号：US20230051612A1

公开(公告)日：2023-02-16

申请号：US17903594

申请日：2022-09-06

Applicant: Worcester Polytechnic Institute

Inventor： Himanshu Tanvar ,  Brajendra Mishra

IPC: C01F7/0653 ,  C01F7/066

Abstract: Bauxite residue recovery includes mixing a solution of hydrochloric acid (HCL) according to a predetermined concentration, and adding the HCL solution to a quantity of raw red mud recovered from industrial operations as waste material. The highly alkaline property of the bauxite residue, commonly known as red mud is at least partially neutralized from the HCL, and makes the resulting washed red mud more amenable to subsequent uses in various applications in fields such as construction, wastewater treatment, and metal recovery processes. The process recovers washed red mud from the red mud and HCL solution by filtering the raw red mud and HCL solution for generating a stream of leach liquor from the filtrate and the recovered washed red mud from the residue. The neutralized red mud is further treated to extract metals such as calcium, iron, aluminum, silicon, and titanium.

公开(公告)号：US20180297856A1

公开(公告)日：2018-10-18

申请号：US15916668

申请日：2018-03-09

Applicant: Worcester Polytechnic Institute

Inventor： Myungwon Jung ,  Brajendra Mishra

IPC: C01G31/02 ,  C22B34/22 ,  C22B5/10

Abstract: 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 (V2O5).