SYSTEM AND METHOD FOR BENEFICIATING AND COLLECTING LITHIUM USING A FLUIDIZED BED REACTOR

Abstract

A method for concentrating and collecting lithium and lithium compounds via a fluidized bed reactor is disclosed. A hopper receives crushed and pulverized lithium ore, and a feeder tube transfers the crushed and pulverized lithium ore to a fluidized bed reactor. An air mixing chamber receives pressurized air from a pressurized gas inlet and a distributor plate is positioned between the air mixing chamber and the fluidized bed reactor to distribute air pressure across the bottom of the fluidized bed reactor. A cyclone receives a material from the fluid bed reactor and transmits the material to a flume for collection or redistribution through a series of fluid bed reactors for further refinement.

Description

TECHNICAL FIELD

Embodiments relate generally to fluid bed reactors and methods for processing lithium using the same. More specifically, the embodiments relate to a method for increasing lithium concentrations, separating refractory ore and reducing impurities using a fluid bed reactor.

BACKGROUND

A fluidized bed reactor is a type of reactor device which can be used to conduct a variety of multi-phase chemical reactions, namely in the petroleum and chemical processing industries. A fluid (gas or liquid) is passed through a solid granular material at high enough velocity to suspend the solid and cause the solid to behave as a fluid, commonly referred to as the process of fluidization.

A porous plate, known as a distributor or distributor plate, supports the solid substrate material in the fluidized bed reactor. Fluid is forced through the distributor up through the solid substrate material. At low fluid velocities, the solid substrate material remains in place as the fluid passes through the voids between the solid substrate material. This is commonly referred to as a packed bed reactor. As the fluid velocity is increased, the reactor will reach a stage where the force of the fluid on the solids is enough to balance the weight of the solid material, known as incipient fluidization. The speed at which this occurs is known as the minimum fluidization velocity. Once this minimum fluidization velocity is surpassed, the contents of the reactor bed begin to expand and swirl, and the reactor is now a fluidized bed. In such, various flow regimes can be observed depending on the operating conditions and properties of the solid phase.

In recent years, fluidized bed reactors have been used to produce gasoline and other fuels, as well as rubber, vinyl chloride, polyethylene, styrenes, and polypropylene. Various utilities also use FBRs for coal gasification, nuclear power plants, and water and waste treatment settings. Compared to other known methods, fluidized bed reactors allow for a cleaner, more efficient process than previous technologies.

Lithium and its compounds have many industrial applications, including heat-resistant glass and ceramics, as an additive for iron, and lithium-ion batteries. Further, lithium is used in biological systems (often in trace amounts) and is known as a mood stabilizer and antidepressant in the treatment of some mental illnesses.

In the last 100 years, the demand for lithium has increased drastically, leading to a boom in the lithium extraction industry. Historically, lithium and its compounds were isolated and extracted from solid rock. More recently, mineral springs, brine deposits, and lithium bearing clay stones have become the primary source of lithium. Isolating and extracting lithium, in many cases, causes significant environmental and health hazards. This includes requiring high volumes of water to perform the process which may not be readily available in some locations where lithium is found. Further, lithium extraction is known to cause water contamination, respiratory problems, ecosystem degradation and damage to the natural landscape.

SUMMARY OF THE INVENTION

This summary is provided to introduce a variety of concepts in a simplified form that is disclosed further in the detailed description of the embodiments. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

Embodiments described herein related to a method for concentrating and collecting lithium and lithium compounds via a fluidized bed reactor are disclosed. A hopper receives crushed and pulverized lithium ore, and a feeder tube transfers the crushed and pulverized lithium ore to a fluidized bed reactor. An air mixing chamber receives pressurized air from a pressurized gas inlet and a distributor plate is positioned between the air mixing chamber and the fluidized bed reactor to distribute air pressure across the bottom of the fluidized bed reactor. A cyclone receives concentrated material from the fluid bed reactor which slows particle velocities and allows the material to be collected. The system provides an advantageous means for extracting and collecting lithium while reducing water requirements inundating methods known in the current arts of lithium extraction.

In one aspect, the concentrated lithium includes a concentrated lithium compound.

In one aspect, the crushed and pulverized lithium ore is a lithium claystone or a lithium brine evaporite.

In one aspect, the fluid bed reactor includes one or more internal heating elements.

In one aspect, the air mixing chamber is in fluid communication with a de-humidifier to prevent moisture from clumping the crushed and pulverized lithium ore in the fluidized bed reactor.

In one aspect, the air mixing chamber is in fluid communication with a heater to improve fluidization within the fluidized bed reactor.

In one aspect, the flume includes a fluidized bed conveyor.

In one aspect, the cyclone runs excess fluidized sediment back to the bottom of the fluidized bed reactor to maintain turbulence within the fluidized bed reactor.

In one aspect, flush mounted sensors are positioned on the fluidized bed reactor, the sensors monitor particle velocities, measure particle density and mineralogy via hyperspectral imaging.

In one aspect, the hopper includes a motorized internal agitator to prevent the crushed and pulverized lithium ore from packing and to distribute heat.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the embodiments, and the attendant advantages and features thereof, will be more readily understood by references to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1A illustrates a flow chart of the method for concentrating and collecting lithium using a fluidized bed reactor, according to some embodiments;

FIG. 1B illustrates a flow chart of the method for concentrating and collecting lithium using a fluidized bed reactor, according to some embodiments;

FIG. 2 illustrates a schematic of the fluidized bed reactor system for concentrating and collecting lithium and/or lithium compounds, according to some embodiments; and

FIG. 3 illustrates a schematic of the fluidized bed reactor system for concentrating and collecting lithium and/or lithium compounds, according to some embodiments.

DETAILED DESCRIPTION

The specific details of the single embodiment or variety of embodiments described herein are set forth in this application. Any specific details of the embodiments are used for demonstration purposes only, and no unnecessary limitation or inferences are to be understood therefrom.

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of components related to the system. Accordingly, the device components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

In reference to FIG. 1A and FIG. 1B, a method for concentrating and collecting lithium using a fluidized bed reactor is provided. In step 100, crushed and pulverized lithium ore is fed into a hopper of a fluidized bed reactor. The crushed and pulverized lithium ore may either be claystone or lithium brine evaporite. In some embodiments, the crushed and pulverized lithium ore is about 10-microns in diameter. In step 105, the hopper funnels the crushed and pulverized lithium ore into a feeder tube via a worm drive gear at a constant rate. In step 110, the fluid bed reactor differentiates and concentrates lithium by density, thus separating it from heavier elements present in the ore. In step 115, pressurized air is fed into the fluidized bed reactor either through compressed air or via industrial scale blowers.

In step 120, air is de-humidified to prevent moisture from clumping material in the fluidized bed reactor. In step 125, air is heated to improve fluidization within the fluidized bed reactor, and in step 130, air is mixed in the chamber to prevent turbulence and equalize pressure across the face of the gas distributor plate. In step 135, the gas distributor plate generates even air pressure at the base of the fluidized bed reactor. In step 140, air escape nozzles allow excess air pressure to be released from the top of the fluidized bed reactor to allow proper fluidization of material and to prevent pressure buildup therein. In step 145, material (i.e., lithium concentrate) is diverted out of the fluidized bed reactor and the velocity is reduced as the material enters the cyclone, allowing the material to settle. In step 150, the lithium concentrate is either collected or sent through a secondary (or plurality of) fluidized bed reactors for further refinement.

Testing was performed at room temperature for both materials and fluidizing gases. Optimal variables such as time for processing, gas and solids temperatures, moisture content, etc., for fluidizing lithium ore will depend on the individual industrial scale application and specific composition of lithium ore being processed. There will exist an ideal FBR configuration, temperature, pressure, humidity level, etc. for any given application and material being sorted.

FIG. 2 illustrates an exemplary schematic of a fluid bed reactor 200. FIG. 3 illustrates an exemplary schematic of a fluidized bed reactor system 200 which may be used to perform the process described herein. Pulverized lithium ore 201 is added to the hopper 203 fluidized bed reactor 200. In some embodiments, the hopper 203 includes a motorized internal agitator which prevents material packing and distributes heat throughout the hopper 203. Internal heating elements 205 which provide heat to the interior of the hopper 203. The hopper 203 funnels the pulverized lithium ore 201 into the feeder tube 207 via the worm drive (not shown) into the fluidized bed reactor 209. A pressurized gas inlet 213 is in fluid communication with a de-humidifier 215 and a heater 217. The pressurized gas inlet 213 allows for pressurized air (via compressed air or industrial scale blower) to be forced into an air mixing chamber 219 at the bottom 220 of the fluidized bed reactor 209. Air is mixed in the air mixing chamber 219 to prevent turbulence and equalize pressure across the surface 221 of the gas distributor plate 223.

In further reference to FIG. 2, the distributor plate 223 facilitates the generation of an even air pressure at the bottom 220 of the fluidized bed reactor 209. One or more gas escape nozzles 225 are positioned at the top 227 of the fluidized bed reactor 209 to allow excess gas to escape and thus maintain a suitable pressure within the interior of the fluidized bed reactor 209. A cyclone 229 is positioned to allow material 231 (i.e., the concentrated lithium) to exit the fluidized bed reactor 209 and eventually be collected. In some embodiments, the collected material 231 is resent through the hopper 203 and the process is repeated.

In some embodiments, the distributor plate 223 is a porous plate to maximize the ability of providing even air pressure at the bottom of the fluidized bed reactor.

In some embodiments, the fluidized bed reactor 209 includes a flush-mounted nozzle 233 to permit the addition of dye or binding agent sprayers.

In some embodiments, the cyclone 229 transmits excess fluidized sediment back to the bottom 220 of the fluidized bed reactor 209. This helps maintain turbulence and fluidization within the fluidized bed reactor 209.

In some embodiments, the material 231 is diverted to a flume 235 to permit the collection of the material 231. The flume 231 may be fluidized via a fluidized bed conveyor 237 in some embodiments.

A benefit of using a fluidized bed reactor to sort leachable and refractory ores, and other minerals from waste rock is the ability to eliminate the need for water which is used in high quantities during conventional ore extraction processes. The water used in conventional ore extraction processes may also be contaminated with heavy metals, harsh acids, and other toxins that require expensive water treatment facilities. Fluidized bed reactors use significantly less energy than other conventional processes. Electricity is used to run conveyors, screw drives, heaters/de-humidifiers and industrial blowers, but gravity does most of the work. A lithium mining and ore processing facility could operate entirely on electricity (utilizing solar/hydro-electric/nuclear) and be completely carbon free and environmentally friendly.

Another benefit to using an FBR is that they can be arranged in series or a circuit, to continuously refine economic ores with minimal added energy and very little waste. Lithium bearing claystones, for instance, contain a wide range of economic elements, including rare earths, as well as non-economic calcium, aluminum, iron, magnesium and manganese, etc. that are concentrated and captured as they are separated from lithium. By concentrating the ore with this method, you can significantly lower ore cut-off grades to process material that is currently below economic grades. Current market cut-off grade for lithium samples tested was at 600 parts per million (ppm) Lithium. Based on current mining and processing industry costs, mine operators can only mine and process ore that contains a minimum of 600 ppm Lithium, all else is considered non-economic waste.

Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

In this disclosure, the descriptions of the various embodiments have been presented for purposes of illustration and are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. Thus, the appended claims should be construed broadly, to include other variants and embodiments, which may be made by those skilled in the art.

It will be appreciated by persons skilled in the art that the present embodiment is not limited to what has been particularly shown and described hereinabove. A variety of modifications and variations are possible in light of the above teachings without departing from the following claims.

Claims

1. A method for concentrating and collecting lithium and lithium compounds via a fluidized bed reactor is disclosed, the method comprising the steps of:

a. receiving, via a hopper, crushed and pulverized lithium ore;

b. transferring, via a feeder tube, the crushed and pulverized lithium ore to a fluidized bed reactor;

c. receiving, via an air mixing chamber, a pressurized gas inlet emitting pressurized air and emitting the pressurized air through a distributor plate positioned between the air mixing chamber and the fluidized bed reactor;

d. receiving, via a cyclone, concentrated lithium from the fluid bed reactor;

e. transmitting the concentrated lithium to a flume; and

f. collecting the concentrated lithium.

2. The method of claim 1, wherein the concentrated lithium includes a concentrated lithium compound.

3. The method of claim 2, wherein the crushed and pulverized lithium ore is a lithium claystone or a lithium brine evaporite.

4. The method of claim 3, wherein the fluid bed reactor includes one or more internal heating elements.

5. The method of claim 4, wherein the air mixing chamber is in fluid communication with de-humidifier to prevent moisture from clumping the crushed and pulverized lithium ore in the fluidized bed reactor.

6. The method of claim 5, wherein the air mixing chamber is in fluid communication with a heater to improve fluidization within the fluidized bed reactor.

7. The method of claim 6, wherein the flume includes a fluidized bed conveyor.

8. The method of claim 7, wherein the cyclone runs excess fluidized sediment back to a bottom of the fluidized bed reactor to maintain turbulence within the fluidized bed reactor.

9. The method of claim 8, further comprising a flush mounted nozzle and sensors positioned on the fluidized bed reactor, the flush mounted nozzle to permit the addition of a dye or binding agent sprayer, the sensors to measure velocity, density and mineralogy.

10. The method of claim 9, wherein the hopper includes a motorized internal agitator to prevent the crushed and pulverized lithium ore from packing and to distribute heat.

11. A system for concentrating and collecting lithium and lithium compounds is disclosed, the system comprising:

a. a hopper to receive crushed and pulverized lithium ore;

b. a feeder tube to transfer the crushed and pulverized lithium ore to a fluidized bed reactor;

c. an air mixing chamber to receive pressurized air from a pressurized gas inlet;

d. a distributor plate positioned between the air mixing chamber and the fluidized bed reactor; and

e. a cyclone to receive a material from the fluid bed reactor and transmit the material to a flume.

12. The system of claim 11, wherein the material is concentrated lithium or a concentrated lithium compound.

13. The system of claim 12, wherein the crushed and pulverized lithium ore is a lithium claystone or a lithium brine evaporite.

14. The system of claim 13, wherein the fluid bed reactor sorts and concentrates the material by density.

15. The system of claim 14, wherein the air mixing chamber is in fluid communication with de-humidifier to prevent moisture from clumping the crushed and pulverized lithium ore in the fluidized bed reactor.

16. The system of claim 15, wherein the air mixing chamber is in fluid communication with a heater to improve fluidization within the fluidized bed reactor.

17. The system of claim 16, wherein the flume includes a fluidized bed conveyor.

18. The system of claim 17, wherein the cyclone diverts excess fluidized sediment to the bottom of the fluidized bed reactor for collection or further refinement.

19. The system of claim 18, further comprising a flush mounted nozzle positioned on the fluidized bed reactor, the flush mounted nozzle to permit the addition of a dye or binding agent sprayer.