Dimensionally controlled 'engineered polymer bubble' for flotation separation

Patent metadata

Field	Value
Publication number	US-2015083646-A1
Application number	US-201314387692-A
Country	US
Kind code	A1
Filing date	Apr 1, 2013
Priority date	Mar 30, 2012
Publication date	Mar 26, 2015
Grant date	—

Abstract

Apparatus is provided featuring a first and second cells. The first cell receives an ore slurry having mineral particles of interest, receives unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, causes the unexpanded polymer microspheres to expand substantially in volume into expanded polymer microspheres having a substantially increased sphere surface area, and provides an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest. The second cell receives the expanded polymer microsphere foam layer, and causes the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest. The second cell may also provide a mineral concentrate output having the mineral particles of interest.

First claim

What is claimed is:

1 . Apparatus comprising:
a first cell configured to receive an ore slurry having mineral particles of interest, to receive unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, to cause the unexpanded polymer microspheres to expand substantially in volume into expanded polymer microspheres having a substantially increased sphere surface area, and to provide an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest; and a second cell configured to receive the expanded polymer microsphere foam layer, and to cause the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest.

2 . Apparatus according to claim 1 , wherein the first cell comprises a flotation cell.

3 . Apparatus according to claim 1 , wherein the first cell comprises an agitator configured to cause or induce agitation to mix the ore slurry and polymer microspheres.

4 . Apparatus according to claim 1 , wherein the unexpanded polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand substantially in volume into the expanded polymer microspheres having the substantially increased sphere surface area when received in the first cell.

5 . Apparatus according to claim 4 , wherein the blowing agent comprises a liquid that responses to a change in temperature and transforms into a gas.

6 . Apparatus according to claim 4 , wherein the blowing agent comprises a gas that responses to a change in temperature and transforms from a low pressure phase into a high pressure phase.

7 . Apparatus according to claim 1 , wherein the first cell is configured to maintain the ore slurry at a predetermined temperature, and the unexpanded polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand substantially in volume into the expanded polymer microspheres having the substantially increased sphere surface area when received in the first cell.

8 . Apparatus according to claim 7 , wherein the unexpanded polymer microspheres are cooled or chilled to a temperature below the predetermined temperature prior to induction to the first cell.

9 . Apparatus according to claim 1 , wherein the expanded polymer microspheres are configured to become buoyant and create an increased bubble flux in the ore slurry, presenting surface area for mineral bearing particles to attach to and be lifted to the surface and form the expanded polymer microsphere foam layer.

10 . Apparatus according to claim 1 , wherein the expanded polymer microsphere foam layer takes the form of an agglomerated mass of expanded spheres on the surface to be skimmed and moved to, or spilled over into a spillover container and moved to, the second cell, including a release stage.

11 . Apparatus according to claim 1 , wherein the second cell comprises a release tank in the form of a re-pressurization cell tank or a condensation cell or tank configured to collapse the expanded polymer microspheres substantially in volume into the collapsed polymer microspheres that results in the mechanical shearing off of the attached mineral particles of interest.

12 . Apparatus according to claim 4 , wherein the second cell is configured to be filled with the expanded polymer microsphere foam layer or mineral rich foam, and to be pressurized to a nominally elevated level, or chilled to a lower temperature, such that the blowing agent reverses through a transition phase, including either returning from a gas phase to a liquid phase or returning from a high pressure phase to a low pressure phase.

13 . Apparatus according to claim 1 , wherein the mineral particles of interest separate from the collapsed polymer microspheres due to gravitation separation, including where minerals sink in the second cell and where the unexpanded polymer microspheres tend to remain nominally buoyant and float.

14 . Apparatus according to claim 1 , wherein the second cell is also configured to provide either a mineral concentrate output having the mineral particles of interest, or a discarded foam output having the collapsed polymer microspheres, or both.

15 . Apparatus according to claim 1 , wherein the molecules comprise a functional group having a chemical bond for attaching the mineral particles of interest.

16 . Apparatus according to claim 1 , wherein the volume of the expanded polymer microspheres is about 50 times the volume of the unexpanded polymer microspheres.

17 . A method comprising:
in a first cell, receiving an ore slurry having mineral particles of interest, receiving unexpanded polymer microspheres comprising a surface having mineral collector chemistry attached thereto with molecules for attaching the mineral particles of interest, causing the unexpanded polymer microspheres to expand substantially in volume into expanded microspheres having a substantially increased sphere surface area, and providing an expanded polymer microsphere foam layer comprising the expanded polymer microspheres with attached mineral particles of interest; and in a second cell, receiving the expanded polymer microsphere foam layer, and causing the expanded polymer microspheres to collapse substantially in volume into collapsed polymer microspheres having a substantially reduced sphere surface area that results in a mechanical shearing off of the attached mineral particles of interest.

18 . A method according to claim 17 , wherein the method comprises configuring the first cell a flotation cell.

19 . A method according to claim 17 , wherein the method comprises configuring the first cell with an agitator to cause or induce agitation to mix the ore slurry and polymer microspheres.

20 . A method according to claim 17 , wherein the method comprises configuring the unexpanded polymer microspheres with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand substantially in volume into the expanded polymer microspheres having the substantially increased sphere surface area when received in the first cell.

21 . A method according to claim 20 , wherein the method comprises configuring the blowing agent with a liquid that responses to a change in temperature and transforms into a gas.

22 . A method according to claim 20 , wherein the method comprises configuring the blowing agent with a gas that responses to a change in temperature and transforms from a low pressure phase into a high pressure phase.

23 . A method according to claim 17 , wherein the method comprises configuring the first cell to maintain the ore slurry at a predetermined temperature, and the unexpanded polymer microspheres are configured with a blowing agent encapsulated therein that has a trigger temperature set below the predetermined temperature so as to cause the unexpanded polymer microspheres to expand substantially in volume int

Assignees

• Cidra Corporate Services Inc

Inventors

• Didden Francis K
• Kersey Alan D
• Davis Michael A
• Rothman Paul J
• Fernald Mark R
• O'Keefe Christian V
• Adamson Douglas H

Classifications

• B03D1/082

  of the froth product, e.g. washing · CPC title

• B03B5/28

  by sink-float separation · CPC title

• B03D1/023 Primary

  Carrier flotation; Flotation of a carrier material to which the target material attaches · CPC title

• B03D1/1406

  with special arrangement of a plurality of flotation cells, e.g. positioning a flotation cell inside another · CPC title

• C02F1/24

  by flotation (C02F1/465 takes precedence) · CPC title