Plant and method for recovering metals and/or metal oxides from industrial process waste, in particular refinery waste

Patent metadata

Field	Value
Publication number	US-2018017327-A1
Application number	US-201615546580-A
Country	US
Kind code	A1
Filing date	Feb 5, 2016
Priority date	Feb 6, 2015
Publication date	Jan 18, 2018
Grant date	—

Abstract

A plant for recovering metals and/or metal oxides from industrial process waste, in particular oil product refining waste, comprises a furnace; a feed line connected to a main inlet of the furnace and configured to feed the furnace with a solid waste containing metals, in particular in oxide form; an outlet line, connected to a solid phase outlet of the furnace and configured to draw a metal-enriched solid phase out of the furnace; the furnace is a belt conveyor furnace having a belt conveyor closed in a loop with a substantially horizontal configuration and having a top face, which receives the waste to treat and conveys it between two longitudinal opposite ends of the belt conveyor furnace respectively provided with the main inlet and the solid phase outlet.

First claim

1 - 28 . (canceled)

29 . A plant configured to recover at least one of a metal and a metal oxide from industrial process waste, said plant comprising:
a belt conveyor furnace including:
an inner chamber extending along a substantially horizontal longitudinal axis, and
a belt conveyor housed in the inner chamber and closed in a loop with a substantially horizontal configuration along the axis, said belt conveyor including a top face configured to receives a solid waste containing a metal to treat and configured to convey the solid waste along the axis in the inner chamber between a first longitudinal end of the belt conveyor furnace where a main inlet is located and a second, opposite longitudinal end of the belt conveyor furnace where a solid phase outlet is located,
an inlet line connected to the main inlet of the belt conveyor furnace and configured to feed the belt conveyor furnace with the solid waste, and an outlet line connected to the solid phase outlet of the belt conveyor furnace and configured to draw a metal-enriched solid phase out from the belt conveyor furnace.

30 . The plant of claim 29 , wherein:
the first end of the belt conveyor furnace is associated with a flue gas outlet connected to a flue gas discharge line equipped with a suction fan, and the second end of the belt conveyor furnace is associated with a gas phase inlet connected to a gas inlet line equipped with a supply fan and configured to supply combustion air to the belt conveyor furnace.

31 . The plant of claim 29 , wherein the belt conveyor furnace is associated with a temperature adjusting system including at least one of:
a series of injectors of one of: cooling water and air which are axially spaced apart from one another along the axis, and a series of burners which are axially spaced apart from one another along the axis.

32 . The plant of claim 29 , further comprising a pre-treatment unit positioned upstream of the belt conveyor furnace along a path of the solid waste to treat, said pre-treatment unit configured to reduce a water content of the solid waste prior to the solid waste being fed to the belt conveyor furnace.

33 . The plant of claim 32 , wherein the pre-treatment unit includes one of: a solid-liquid separation apparatus, and a dryer.

34 . The plant of claim 32 , wherein the pre-treatment unit includes:
a centrifuge having an inlet connected to a supply line configured to supply the solid waste to treat to the plant, a solid outlet set at a first axial end of the centrifuge, said solid outlet being connected to the main inlet of the belt conveyor furnace, and a liquids outlet set at a second axial end of the centrifuge, said liquids outlet being connected to a recirculation line.

35 . The plant of claim 29 , further comprising a flue gas treatment group connected to a flue gas outlet of the belt conveyor furnace and configured to receive and process flue gas produced in the belt conveyor furnace.

36 . The plant of claim 35 , wherein the flue gas treatment group includes a filtering unit including one of: an electrostatic precipitator and a filter.

37 . The plant of claim 36 , wherein the flue gas treatment group includes a cooling unit positioned upstream of the filtering unit.

38 . The plant of claim 29 , wherein the belt conveyor is made of a material resistant to a temperature of at least 650° C.

39 . The plant of claim 29 , wherein the belt conveyor furnace is equipped with a chemical dispensing system including a series of nozzles axially spaced along the axis in the inner chamber and connected to a chemical supply line, said series of nozzles configured to spread chemicals to at least one of: the inner chamber, the solid waste lying on the belt conveyor along the axis, and at least one predetermined zone of the inner chamber.

40 . The plant of claim 39 , wherein the chemicals include a solution of sodium carbonate.

41 . The plant of claim 29 , further comprising a leaching unit positioned downstream of the belt conveyor furnace and connected to the solid phase outlet of the belt conveyor furnace, said leaching unit configured to leach a solid phase exiting from the belt conveyor furnace to produce an aqueous solution containing metals extracted from said solid phase.

42 . The plant of claim 41 , further comprising at least one metal separation unit positioned downstream of the leaching unit and configured to at least partially separate the metals contained in the solution exiting from the leaching unit.

43 . The plant of claim 29 , wherein the industrial process waste comprises oil product refining waste.

44 . The plant of claim 29 , wherein solid waste containing the metal comprises a solid waste containing a metal in oxide form.

45 . A method for recovering at least one of a metal and a metal oxide from industrial process waste, said method comprising:
spreading a solid waste on a top face of a belt conveyor closed in a loop with a substantially horizontal configuration along an axis, advancing the belt conveyor along the axis to move the solid waste lying on the belt conveyor along an advance direction defined by the axis while supplying heat to the solid waste to induce a combustion of the solid waste to reduce a carbon content of said solid waste and produce a metal enriched solid phase, removing, from the face of the belt conveyor, the metals enriched solid phase, and extracting metals from said metals enriched solid phase.

46 . The method of claim 45 , further comprising:
supplying at least one of: combustion air and combustion gas to assist the combustion of the solid waste, and removing flue gas produced by the combustion of the solid waste, wherein the combustion air and the flue gas are circulated in a counter-current direction from the advance direction of the solid waste.

47 . The method of claim 45 , further comprising adjusting a temperature of the combustion of the solid waste by at least one of: a series of injectors of cooling water axially spaced apart from one another along the axis, a series of injectors of air axially spaced apart from one another along the axis, and a series of burners axially spaced apart from one another along the axis.

48 . The method of claim 45 , further comprising pre-treating the solid waste by removing water from the solid waste before the combustion of the solid waste to reduce a water content of the solid waste.

49 . The method of claim 48 , wherein the pre-treatment includes one of: separating a solid-liquid, and drying.

50 . The method of claim 48 , wherein the pre-treatment is performed by a centrifuge.

51 . The method of claim 45 , further comprising a flue gas treatment in which a flue gas produced in the combustion of the solid waste is filtered.

52 . The method of claim 51 , wherein the flue gas is filtered by one of: an electrostatic precipitator and a filter.

53 . The method of claim 51 , wherein the flue gas treatment includes cooling the flue gas before the flue gas is filtered.

54 . The method of claim 45 , wherein the belt conveyor is made of a material resistant to a temperature of at least 650° C.

55 . The method of claim 45 , further comprising spreading, by a series of nozzles axially spaced along the axis, one or more chemicals to at least one of: in a chamber of the belt conveyor, on the solid waste lying on the belt conveyor longi

Assignees

• Saipem Spa

Inventors

• Galati Rosario
• Bruno Lorenzo
• Carlessi Lino

Classifications

• C22B7/006

  Wet processes · CPC title

• C22B1/005 Primary

  Preliminary treatment of scrap (C22B1/02 - C22B1/26 take precedence) · CPC title

• C22B9/10

  with refining or fluxing agents; Use of materials therefor, {e.g. slagging or scorifying agents}(C22B9/18 takes precedence){(C22B9/006 takes precedence)} · CPC title

• C22B7/00

  Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; {Methods of a general interest or applied to the winning of more than two metals (briquetting of scrap C22B1/248; preliminary treatment of scrap C22B1/005)} · CPC title

• C22B34/34

  Obtaining molybdenum {(treatment or purification of solutions by adsorption on solids C22B3/24, by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42; preparation of molybdenum involving liquid-liquid extraction, adsorption or ion-exchange C01G39/003)} · CPC title