Claims:WE CLAIM:

1. A method for producing high purity and large surface area magnetite powder, the method comprising:
heating powdered iron oxide in a reduction furnace at a temperature ranging from about 350 oC to about 500 oC in presence of a reductant gas for a predetermined time period to obtain magnetite powder; and
cooling the magnetite powder in the reduction furnace to room temperature under an inert atmosphere,
wherein, the magnetic powder comprises a total iron content Fe (T) of at least 71.5 wt.% and a surface area of at least 4.5 m2/g.

2. The method as claimed in claim 1, wherein the powdered iron oxide is produced by spray roasting of pickling solution obtained during an acid recovery process.

3. The method as claimed in claim 1, wherein the powdered iron oxide comprises a composition of: iron Fe (T) at about 69.55 wt.% , ferrous oxide (FeO) at about 0.65 wt.%, silicon dioxide (SiO2) at about 0.027 wt.%, calcium oxide (CaO) at about 0.06 wt.%, magnesium oxide (MgO) at about 0.015 wt.%, manganese oxide (MnO) at about 0.24 wt.%, aluminum oxide (Al2O3) at about 0.18 wt.%, sulphur (S) at about 0.019 wt.%, carbon (C) at about 0.074 wt.%, along with at least one or more additional elements selected from chromium (Cr), titanium (Ti), copper (Cu) and phosphorus (P) at various wt.% and balance being incidental elements.

4. The method as claimed in claim 1, wherein the reduction furnace is at least one of pusher type, steel belt type and walking beam type furnace.

5. The method as claimed in claim 1, wherein the powdered iron oxide is loaded onto a bed portion of the reduction furnace, and height of the powdered iron oxide on the bed portion ranges from about 9 mm to about 15 mm.

6. The method as claimed in claim 1, wherein the reductant gas is at least one of hydrogen rich gas and carbon monoxide gas.

7. The method as claimed in claim 1, wherein the reductant gas is supplied to the reduction furnace at a gas flow rate ranging from about 1 Nm3/h to about 1.6 Nm3/h.

8. The method as claimed in claim 1, wherein the reductant gas flows in at least one of counter-current direction and concurrent direction to the flow of the powdered iron oxide inside the reduction furnace.

9. The method as claimed in claim 1, wherein the predetermined time for reduction ranges from about 10 minutes to about 60 minutes.

10. The method as claimed in claim 1, wherein the inert atmosphere is maintained by passing at least one of nitrogen gas and argon gas into the reduction furnace.

11. The method as claimed in claim 1 comprising screening of the magnetic powder after cooling.

12. The method as claimed in claim 11, wherein the screening is performed through a 100-mesh sieve to obtain a particle size at most of about 150 µm.

13. The method as claimed in claim 1, wherein the magnetite powder processed by the method exhibits an apparent density of at most 0.324 g/cc.

14. A Magnetite powder obtained from reduction of powdered iron oxide through a method as claimed in claim 1, with a total iron content Fe (T) of at least about 71.5 wt.% having a BET surface area of at least about 4.5 m2/g, an apparent density of at most 0.324 g/cc and particle size of at most 150 µm.
, Description:TECHNICAL FIELD

The present disclosure in general relates to a field of material science and metallurgy. Particularly, but not exclusively, the present disclosure relates to manufacturing magnetite powder. Further embodiments of the disclosure disclose a method for producing high purity and large surface area magnetite powder.

BACKGROUND OF THE DISCLOSURE

Magnetite is known to be an important iron oxide compound, due to its iron content and magnetic properties. High purity magnetite has been used in pigment industries such as sulphur sequestration, drilling mud applications in petrochemical sector associated with mining activities and in coal cleaning process due to its pitch-black colour. Magnetite has been usually classified into two types: naturally occurring, such as, ores and synthetic magnetite. Naturally occurring ores are an important raw material in iron and steel making industries as the iron is used as a primary source of in blast furnaces. Another type of magnetite, such as synthetic magnetite is usually prepared from a range of raw materials. The most widely used raw material in the preparation of synthetic magnetite is synthetic hematite. This synthetic hematite is produced by spray roasting of pickling solution obtained during an acid recovery process. Further, this synthetic hematite is reduced in the presence of reducing gases like carbon monoxide or hydrogen rich gases like hydrogen and methane to produce magnetite.

Conventionally, there are known process to produce the magnetite from synthetic hematite. Such known process includes charging of synthetic hematite in a pelletized form, and heating the same in a reducing atmosphere of carbon monoxide or hydrogen in high temperature range of 900 °C to 1100 °C. However, preparation of such magnetite is a challenge as there is absence of optimized process parameters such as a defined gas to solid ratio, flow rate etc. for the for production of haematite. Another conventional process for preparation includes employing hematite from spent pickling solution in a reducing atmosphere especially in presence of methane or natural gas in the temperature regime of 700°C to 1300 °C to produce the magnetite with purity of 98 %. However, both of these processes require high temperature operations to yield magnetite. Since the magnetite particles possess high surface area, at higher temperatures the obtained pure magnetite particles are vulnerable to sintering with each other. This leads to minimised surface energy and hence result in loss of desired high surface area. Further, the high temperature magnetite production process requires enormous amount of energy which in turn makes the synthesis process economically less feasible. Although in some instances, at low temperatures (200 oC to 700 oC) and by simple reduction process, magnetite may be produced using synthetic hematite and hydrogen rich reducing gases; however, they don’t report the production of pure magnetite.

Additionally, production of a high surface area or porous magnetite from reduction of natural hematite, natural iron compounds such as siderite, pyrite etc have their own flaws such as, limited availability, uneconomical processes and the like. Further, technologies such as fluidization, electrocoagulation are also employed for the production of high surface area, high purity magnetite powder, however such processes are complex, laborious and energy intensive.

The present disclosure is directed to overcome one or more limitations stated above or any other limitation associated with the prior arts.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the prior art are overcome by a method and a product as disclosed and additional advantages are provided through the method as described in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, there is provided a method for producing high purity and large surface area magnetite powder. The method involves heating powdered iron oxide in a reduction furnace at a temperature ranging from about 350 °C to about 500 oC in presence of a reductant gas for a predetermined time period to obtain magnetite powder. Magnetic powder in the reduction furnace is then cooled to room temperature under an inert atmosphere. The obtained magnetic powder comprises a total iron content Fe (T) of at least 71.5 wt.% and a surface area of at least 4.5 m2/g.

In an embodiment, the powdered iron oxide is produced by spray roasting of pickling solution obtained during an acid recovery process.

In an embodiment, the powdered iron oxide comprises a composition of iron Fe (T) at about 69.55 wt.% , ferrous oxide (FeO) at about 0.65 wt.%, silicon dioxide (SiO2) at about 0.027 wt.%, calcium oxide (CaO) at about 0.06 wt.%, magnesium oxide (MgO) at about 0.015 wt.%, manganese oxide (MnO) at about 0.24 wt.%, aluminum oxide (Al2O3) at about 0.18 wt.%, sulphur (S) at about 0.019 wt.%, carbon (C) at about 0.074 wt.%, along with at least one or more additional elements selected from chromium (Cr), titanium (Ti), copper (Cu) and phosphorus (P) at various wt.% and balance being incidental elements.

In an embodiment, the reduction furnace is at least one of pusher type, steel belt type and walking beam type furnace.

In an embodiment, the powdered iron oxide is loaded onto a bed portion of the reduction furnace, and height of the powdered iron oxide on the bed portion ranges from about 9 mm to about 15 mm.

In an embodiment, the reductant gas is at least one of hydrogen rich gas and carbon monoxide gas and is supplied to the reduction furnace at a gas flow rate ranging from about 1 Nm3/h to about 1.6 Nm3/h. Further, the reductant gas flows in at least one of counter-current direction and concurrent direction to the flow of the powdered iron oxide inside the reduction furnace.

In an embodiment, the predetermined time for reduction ranges from about 10 minutes to about 60 minutes.

In an embodiment, the inert atmosphere is maintained by passing at least one of nitrogen gas and argon gas into the reduction furnace.

In an embodiment, screening of the magnetic powder is performed after cooling through a 100-mesh sieve to obtain a particle size at most of about 150 µm.

In one non-limiting embodiment, the magnetite powder obtained from reduction of powdered iron oxide comprises a total iron content Fe (T) of at least about 71.5 wt.% having a BET surface area of at least about 4.5 m2/g, an apparent density of at most 0.324 g/cc and particle size of at most 150 µm.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES

The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

Figure.1 is a flowchart illustrating a method for producing high purity and large surface area magnetite powder, according to an exemplary embodiment of the present disclosure.

Figure 2 illustrates X-ray powder diffraction (XRD) analysis of spray roasted powdered iron oxide employed in the present method of producing magnetite powder, according to an exemplary embodiment of the present disclosure.

Figure 3 illustrates X-ray powder diffraction (XRD) analysis of magnetite powder by reduction of spray roasted powdered iron oxide, according to an exemplary embodiment of the present disclosure.

Figure 4 illustrates the optical micrograph of the microstructure of magnetite powder at a magnification of 100X, according to an exemplary embodiment of the present disclosure.

Figures 5a, 5b and 5c illustrate the Scanning Electron Microscopy (SEM) image of magnetite powder obtained by reduction of spray roasted powdered iron oxide at a magnification of 1000X, 5000X and 10000X respectively.

Figure 6 illustrates the Raman spectroscopy of magnetite powder produced by reduction of spray roasted iron oxide.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the description of the disclosure. It should also be realized by those skilled in the art that such equivalent methods do not depart from the scope of the disclosure. The novel features which are believed to be characteristic of the disclosure, as to method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a method that comprises a list of acts does not include only those acts but may include other acts not expressly listed or inherent to such method. In other words, one or more acts in a method proceeded by “comprises… a” does not, without more constraints, preclude the existence of other acts or additional acts in the method.

Embodiments of the present disclosure discloses a method for producing high purity and large surface area magnetite powder. Conventional methods to prepare magnetite power involves high temperature operations which may lead to sintering of high surface area magnetite powder. Large area magnetite powders are produced using natural iron compounds which have limited availability. Further, technologies such as fluidization, electrocoagulation are also employed for the production of high surface area, high purity magnetite powder are complex, laborious and energy intensive. Hence, it is clear from the known prior art that, there is an absence of a single suitable process to produce a combination of high purity and high surface area magnetite powder that is not necessarily ultra-fine in nature or in the nano-size range. Therefore, there is a high need to design a simple, easy, scalable and economically feasible process for production of high purity and high surface area magnetite powder using synthetic hematite at low temperatures with established process parameters without having aforementioned limitations. The present disclosure is directed towards producing high purity and large surface area magnetite powder from synthetic iron oxide at low temperatures with established process parameters.

Accordingly, the method for producing high purity and large surface area magnetite powder involves heating powdered iron oxide in a reduction furnace at a temperature ranging from about 350 °C to about 500 °C in presence of a reductant gas for a predetermined time period to obtain magnetite powder. Magnetic powder in the reduction furnace is then cooled to room temperature under an inert atmosphere. By this process, the obtained magnetic powder comprises a total iron content Fe (T) of at least 71.5 wt.% and a surface area of at least 4.5 m2/g

The present disclosure is explained with the help of figures. However, such exemplary embodiments should not be construed as limitations of the present disclosure, since the method disclosed may be used on magnetite powder prepared from other iron oxide ore where and when such need arises. A person skilled in the art may envisage various such embodiments without deviating from scope of the present disclosure.

Figure.1 is a flowchart illustrating a method for producing high purity and large surface area magnetite powder, according to an exemplary embodiment of the present disclosure. The method is particularly applicable for producing high purity and large surface area magnetite powder. The magnetite powder so obtained via reduction of spray roasting of iron oxide. In an embodiment, the spray roasting of iron oxide may also be extended to the magnetite powder obtained from other type of iron oxide ore as well. The various processing steps are described in their respective order below:

Powdered iron oxide which is being employed for the production of magnetite is a synthetic powder and may be produced by spray roasting of pickling solution obtained during an acid recovery process in steel making plant such as blast furnace or smelting vessel and the like. The powdered iron oxide has a composition of iron Fe (T) at about 69.55 wt.% , ferrous oxide (FeO) at about 0.65 wt.%, silicon dioxide (SiO2) at about 0.027 wt.%, calcium oxide (CaO) at about 0.06 wt.%, magnesium oxide (MgO) at about 0.015 wt.%, manganese oxide (MnO) at about 0.24 wt.%, aluminum oxide (Al2O3) at about 0.18 wt.%, sulphur (S) at about 0.019 wt.%, carbon (C) at about 0.074 wt.%, along with at least one or more additional elements selected from chromium (Cr), titanium (Ti), copper (Cu) and phosphorus (P) at various wt.% and balance being incidental elements.

At block 101, powdered iron oxide of above-mentioned composition may be fed into a reduction furnace such as but not limited to one of pusher type, steel belt type and walking beam type furnace. The powdered iron oxide may be loaded onto a bed portion of the reduction furnace at different heights varying from about 9 mm to about 15 mm.

After loading the, the powdered iron oxide may be subjected to heating at a temperature range of 350 °C to 500 °C for about 10 minutes to 60 minutes in a reduction furnace (as shown in block 102). In an embodiment, heating may be carried out using a suitable heating means in the reduction furnace. Further, the heating is carried out in presence of reduction gas including but not limiting to hydrogen rich gas and carbon monoxide gas. In an exemplary embodiment, hydrogen gas may be used as the reduction gas. During the process of heating the reduction gas may be supplied at predetermined gas flow rate. In an embodiment, the gas flow rate may be in the range from about 1 Nm3/h to about 1.6 Nm3/h. Also, the reductant gas flows in at least one of counter-current direction and concurrent direction to the flow of the powdered iron oxide inside the reduction furnace.

When the iron oxide is made to react with hydrogen or carbon monoxide in presence of heat energy (heating), a reduction reaction may occur leading to the formation of magnetite powder as shown by below chemical equation below.

3Fe2O3+H2---------?2Fe3O4+H2O

3Fe2O3+CO---------?2Fe3O4+CO2

Reduction is loss of oxygen atom from a molecule or the gaining of one or more electrons. Reduction of iron oxide may lead to the formation magnetite. However, oxygen loss during this reduction process only corresponds to a mere 2.4 wt.% and may need to be critically controlled to end up with magnetite having desired properties. An excess gas flow or increased time would result in the formation of iron at above mentioned temperatures and may lead to the formation of undesirable iron-magnetite composite type of product.

At block 103, the obtained magnetic powder is cooled in the reduction furnace to room temperature under an inert atmosphere. The inert atmosphere may be created by passing gas such as but not limited to nitrogen into the reduction furnace. Cooling may be performed via natural cooling or with a force cooling at controlled cooling rate to bring the magnetic powder to room temperature. It is also important to control the reduction and cooling time so that no sintering takes place between the magnetite particles that would result in loss of surface area of the product. In an embodiment, the obtained magnetic powder has total iron content Fe (T) of at least 71.5 wt.% and surface area of at least 4.5 m2/g

Now reference is made to block 104, where magnetic particles may be subjected to a screening process. The screening may be carried through a mesh to obtain the magnetite powder of desired size. In an embodiment, the mesh may be 100-mesh sieve to obtain a particle size at most of about 150 µm. The particles may be irregular in size and highly porous in nature.

Further embodiments of the present disclosure will now be described with examples of different set of process parameters by utilizing powdered iron oxide to produce magnetic powder.

EXAMPLE 1:

In an embodiment of the present disclosure, reduction of irregular spray roasted powdered iron oxide power may occur in presence of pure hydrogen gas as reducing agent at a flow rate of about 1 Nm3/h with height of the powdered iron oxide on the bed portion ranges from about 15 mm.

Composition
(wt.%) Fe(total)
[Fe(t)]
FeO CaO SiO2 S MgO MnO Al2O3 C
Spray Roasted Iron Oxide 69.55

0.65 0.06 0.027 0.019 0.015 0.24 0.18 0.074

Table-1

Referring to table 1 which tabulates the chemical composition of spray roasted powdered iron oxide. This powdered iron oxide may be subjected to reduction roasting in presence of pure hydrogen in a reduction furnace at about 500 oC for about 10 minutes. The resultant magnetite powder may be cooled in the furnace to room temperature by passing nitrogen gas. It may be then directly screened through a 100-mesh sieve.

The obtained magnetite powder may be irregular and highly porous in nature with total iron Fe (T) of 71.8 wt.% and possesses a maximum particle size may not more than 150 µm. The apparent density may be about 0.312 g/cc with a BET surface area of about 4.523 m2/g. These physical properties indicate the presence of high purity and high surface magnetite powder.

Referring to figures. 2 and 3, which are exemplary embodiments of the present disclosure, illustrating graphical representation XRD analysis results for spray roasted powdered iron oxide and magnetite powder respectively. This XRD test may be performed using Copper K-Alpha (CuKa) radiation of wavelength 1.54 Å. The diffracted x-ray beam intensity as a function of the diffracted angle may be recorded. Position of the planes and their intensity respectively may reveal the information about the phase and amount of phase present in the microstructure. A sharp peak present at 2?=35° indicate the formation of magnetite compound after reduction process.

Referring to figure 4, which are exemplary embodiment of the present disclosure, illustrating optical micrograph of the microstructure of magnetite powder at a magnification of 100X. Optical micrograph highlights the porosity present inside the magnetite particles. Now referring to figures 5a, 5b and 5c which illustrate Scanning Electron Microscopy (SEM) image magnetite powder at a magnification of 1000X, 5000X and 10000X respectively. A focused electron beam of 10kv to 15kV may be directed to illuminate the surface sample dispersed over a conducting substrate. The secondary electrons (SE2) which are emitted from very close to the specimen surface are collected using a secondary electron detector equipment attached with SEM to obtain the information for surface morphology. SEM images clearly depict the irregular and highly porous magnetite powder.

Figure 6 indicates the Raman spectroscopy study performed on magnetic powder. Raman Spectra indicates only peaks which may be corresponding to magnetite compound. The absence of any oxidation peak in the Raman spectra clearly depicts the absence of surface oxidation phenomena which would occur on the surface due to this high surface area.

EXAMPLE 2:

In an embodiment of the present disclosure, the irregular spray roasted powdered iron oxide having the composition as defined in Example 1 may be reduced using cracked ammonia gas (hydrogen rich gas) with a flow rate of about 1.6 Nm3/h at about 450 °C for a reduction time of about 15 minutes. The height of the powdered iron oxide on the bed portion ranges about 13 mm. The resultant magnetite powder may be cooled in the furnace to room temperature by passing nitrogen gas. It may be then directly screened through a 100-mesh sieve.

The obtained magnetite powder may be irregular and highly porous. It has a Fe (T) of 71.6 wt. % and possesses a maximum particle size not more than 150 µm. The apparent density is about 0.324 g/cc with a BET surface area of 4.502 m2/g.

EXAMPLE 3:

In an embodiment of the present disclosure, the irregular spray roasted powdered iron oxide having the composition as defined in Example 1 may be reduced using cracked ammonia gas (hydrogen rich gas) with a flow rate of about 1.2 Nm3/h at about 400 °C for a reduction time of about 30 minutes. The height of the powdered iron oxide on the bed portion ranges about 12 mm. The resultant magnetite powder may be cooled in the furnace to room temperature by passing nitrogen gas. It may be then directly screened through a 100-mesh sieve. The obtained magnetite powder may have a Fe (T) of 71.6 wt.% and possesses a maximum particle size not more than 150 µm. The apparent density may be about 0.310 g/cc with a BET surface area of about 4.704 m2/g.

EXAMPLE 4:

In an embodiment of the present disclosure, the irregular spray roasted powdered iron oxide having the composition as defined in Example 1 may be reduced using pure hydrogen gas with a flow rate of about 1.2 Nm3/h at about 350 °C for a reduction time of about 60 minutes. The bed height of the powdered iron oxide may be 9 mm. The resultant magnetite powder may be cooled in the furnace to room temperature by passing nitrogen gas. It may be then directly screened through a 100-mesh sieve.

The obtained magnetite powder comprises total iron Fe (T) of 71.5 wt.% and possessed a maximum particle size not more than 150 µm. The apparent density may be about 0.317 g/cc with a BET surface area of about 4.512 m2/g.

Examples 1 to 4 clearly infer the role or process parameters of the reduction of powdered iron oxide into magnetite powder. When the bed height is kept at a high value, high temperature and low gas flow rate may be required for the reduction process to occur; but time duration required to complete the reduction process may be reduced. On the other hand, when the bed height is at a low value, low temperature and high gas flow rate values may be required for the reduction process to complete, but time duration required to complete the reduction process may be increased. Example 1 to Example 4 produce high porous, high surface area magnetic particles under optimised process parameters.

The present disclosure discloses a simple and efficient method of producing high purity and high surface area magnetite powder without necessarily being in ultrafine or nano particle size ranges. The process may be quick and results in higher productivities and hence can easily be scalable. However, the time of reduction and flow rate of hydrogen rich gas for given reduction temperature may play a very critical role in the reduction process. The magnetite powder with this unique combination of high purity and surface area could be used in the mining industries for coal washing and sulphur sequestration activities in drilling mud applications. Furthermore, this could also have potential favourable applications such as but not limited to environmental and catalysis sector.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.