阅读说明：本技术 一种应急补救的脱磷方法 (Dephosphorization method for emergency remediation ) 是由 冀建立 韩凯峰 江腾飞 朱建强 于宏斌 郝丽霞 孙亮 于 2021-09-17 设计创作，主要内容包括：本申请涉及转炉、精炼LF炉技术领域,尤其涉及一种应急补救的脱磷方法。所述方法包括以下步骤：获取转炉炼钢的钢水中各化学组分的含量；根据所述化学组分的含量和标准磷含量,判定磷含量是否超标；若是,根据所述标准磷含量控制转炉冶炼和/或精炼炉冶炼,进行脱磷；所述转炉冶炼包括转炉炉后进行底吹和控制碱度；所述精炼炉冶炼包括精炼炉固渣。充分利用底吹搅拌和控制碱度的相关工艺对钢水进行控制,使钢水中以磷元素或磷化物存在的磷氧化为P-(2)O-(5)进入炉渣,烧结白灰与炉渣中的碱性氧化物生成磷酸盐,反应生成物P-(2)O-(5)不很稳定,只有进入炉渣中才能除掉。精炼炉冶炼包括增加提高炉渣的熔点,使氧化后的磷在渣中形成稳定的磷酸盐,达到脱磷效果。(The application relates to the technical field of converters and refining LF furnaces, in particular to an emergency remediation dephosphorization method. The method comprises the following steps: obtaining the content of each chemical component in molten steel produced in converter steelmaking; judging whether the phosphorus content exceeds the standard or not according to the content of the chemical components and the standard phosphorus content; if so, controlling converter smelting and/or refining furnace smelting according to the standard phosphorus content to dephosphorize; the converter smelting comprises bottom blowing and alkalinity control after the converter smelting; the refining furnace smelting comprises refining furnace slag solidification. Fully utilizes the related processes of bottom blowing stirring and alkalinity control to control molten steel, and the phosphorus existing in phosphorus element or phosphide in the molten steel is oxidized into P 2 O 5 The slag enters a furnace, lime is sintered, and the furnaceAlkaline oxide in the slag generates phosphate, and reaction product P 2 O 5 Is not very stable and can only be removed by entering slag. The smelting of the refining furnace comprises the steps of increasing and improving the melting point of the slag, so that the oxidized phosphorus forms stable phosphate in the slag to achieve the dephosphorization effect.)

1. A dephosphorization method for emergency remediation, characterized in that the method comprises the following steps:

obtaining the content of each chemical component in molten steel produced in converter steelmaking;

judging whether the phosphorus content exceeds the standard or not according to the content of the chemical components and the standard phosphorus content;

if so, carrying out dephosphorization control on converter smelting and/or carrying out dephosphorization control on refining furnace smelting according to the standard phosphorus content, and realizing emergency remedial dephosphorization;

the dephosphorization control of the converter smelting comprises bottom blowing and alkalinity control after the converter smelting is carried out;

the refining furnace smelting comprises refining furnace slag solidification.

2. The method according to claim 1, wherein the gas flow rate of bottom blowing after the converter furnace is 1200 to 1500NL/min and the time is 5 to 8 min.

3. The method of claim 1, wherein said controlling alkalinity comprises adding sinter lime; the particle size of the sintering lime is 5-35 mm, and the addition amount of the sintering lime is 3-5 kg/t.

4. The method of claim 3, wherein the chemical composition of the sintered lime comprises, in mass fraction, Si0₂: 0-2.5%, CaO: 80-85%, MgO: < 10% and S: less than 0.05%.

5. The method of claim 1, wherein the refining furnace slag solidification comprises:

obtaining a first molten steel temperature for refining molten steel and a first target temperature of molten steel required by a refining furnace;

performing first temperature rise on the refined molten steel and controlling the bottom blowing gas flow of the molten steel according to the first molten steel temperature and the first target temperature;

and when the terminal temperature of the first temperature rise reaches the first target temperature, adding 1-2 kg/t of the sintering lime to obtain the slag with the melting point of 1420-1440 ℃.

6. The method of claim 1, wherein the finer smelting further comprises the steps of:

obtaining a first oxygen content of molten steel entering a refining furnace and a target oxygen content of the refining furnace;

judging whether an oxidant needs to be added to the incoming molten steel or not according to the first oxygen content and the target oxygen content;

if yes, calculating a first feeding amount of the oxidant according to the first oxygen content, the target oxygen content and the oxygen content of the oxidant;

adding the oxidant according to the first feeding amount to obtain oxygenated molten steel;

performing bottom blowing on the oxygen-enriched molten steel in a refining furnace at a first bottom blowing flow rate, adding slag melting materials in batches to a target alkalinity of 5-7, performing electrode slag melting, and performing second temperature rise on the oxygen-enriched molten steel;

obtaining a second target temperature of molten steel required by the refining furnace;

when the terminal temperature of the second temperature rise reaches a second target temperature, stopping electrode slagging, and performing bottom blowing of the refining furnace at a second bottom blowing flow rate;

and (3) continuously and forcibly stirring the oxygen-enriched steel for 4-6min at the gas flow rate of 800-1000 Nl/min to obtain the dephosphorized molten steel.

7. The method as claimed in claim 7, wherein the target oxygen content is 500-600 ppm; the first bottom blowing flow rate is 300-400 NL/min; the second bottom blowing flow rate is 800-1000 NL/min.

8. The method of claim 7, wherein the oxidizing agent comprises oxide spheres or scales; the oxidation ball comprises the following components in percentage by mass: tfe > 65%, CaO > 35%, SiO2 < 5% and other unavoidable impurities.

9. The method of claim 7, wherein the first charge is calculated by the formula:

10. the method according to claim 7, characterized in that the slagging material comprises sintered lime and fluorite, the sintered lime being 4-6kg/t and the fluorite having a mass of 1-2.5 kg/t.

Technical Field

The application relates to the technical field of converters and refining LF furnaces, in particular to an emergency remediation dephosphorization method.

Background

With the continuous upgrade of steel products, domestic large-scale steel enterprises produce more and more enterprises such as household appliances, automobiles, pure iron materials and the like, most of the enterprises adopt a technology of not deoxidizing after the furnace in combination with the purposes of reducing cost and increasing production, and a technology of RH light treatment (or decarburization treatment) after the LF furnace is simply heated or a technology of RH light treatment (or decarburization treatment) directly enters the LF furnace, so that the technology is influenced by factors such as the large waste steel amount, the side materials and the operation of the converter, and the technology can generate the phenomenon that the phosphorus content exceeds the standard.

At present, for the phenomenon that the phosphorus content exceeds the standard, degradation or judgment treatment is generally needed, order cashing is influenced, and a casting blank pressing library is caused.

Disclosure of Invention

The application provides an emergency remedial dephosphorization method, which aims to solve the technical problem that phosphorus in a converter steel tapping sample exceeds the standard in the prior art.

In a first aspect, the present application provides a method of dephosphorisation for emergency remediation, said method comprising the steps of:

obtaining the content of each chemical component in molten steel produced in converter steelmaking;

judging whether the phosphorus content exceeds the standard or not according to the content of the chemical components and the standard phosphorus content;

if so, carrying out dephosphorization control on converter smelting and/or carrying out dephosphorization control on refining furnace smelting according to the standard phosphorus content, and realizing emergency remedial dephosphorization;

the dephosphorization control of the converter smelting comprises bottom blowing and alkalinity control after the converter smelting is carried out;

the refining furnace smelting comprises refining furnace slag solidification.

Optionally, the gas flow rate of bottom blowing performed behind the converter is 1200-1500 NL/min, and the time is 5-8 min.

Optionally, the controlling alkalinity comprises adding sintering lime; the particle size of the sintering lime is 5-35 mm, and the addition amount of the sintering lime is 3-5 kg/t.

Optionally, the chemical composition of the sintering lime comprises SiO in percentage by mass₂: 0-2.5%, CaO: 80-85%, MgO: < 10% and S: less than 0.05%.

Optionally, the refining furnace slag solidification includes:

obtaining a first molten steel temperature for refining molten steel and a first target temperature of molten steel required by a refining furnace;

performing first temperature rise on the refined molten steel and controlling the bottom blowing gas flow of the molten steel according to the first molten steel temperature and the first target temperature;

and when the terminal temperature of the first temperature rise reaches the first target temperature, adding 1-2 kg/t of the sintering lime to obtain the slag with the melting point of 1420-1440 ℃.

Optionally, the refining furnace smelting further comprises the following steps:

obtaining a first oxygen content of molten steel entering a refining furnace and a target oxygen content of the refining furnace;

judging whether an oxidant needs to be added to the incoming molten steel or not according to the first oxygen content and the target oxygen content;

if yes, calculating a first feeding amount of the oxidant according to the first oxygen content, the target oxygen content and the oxygen content of the oxidant;

adding the oxidant according to the first feeding amount to obtain oxygenated molten steel;

performing bottom blowing on the oxygen-enriched molten steel in a refining furnace at a first bottom blowing flow rate, adding slag melting materials in batches to a target alkalinity of 5-7, performing electrode slag melting, and performing second temperature rise on the oxygen-enriched molten steel;

obtaining a second target temperature of molten steel required by the refining furnace;

when the terminal temperature of the second temperature rise reaches a second target temperature, stopping electrode slagging, and performing bottom blowing of the refining furnace at a second bottom blowing flow rate;

and (3) continuously and forcibly stirring the oxygen-enriched steel for 4-6min at the gas flow rate of 800-1000 Nl/min to obtain the dephosphorized molten steel.

Optionally, the target oxygen content is 500-600 ppm; the first bottom blowing flow rate is 300-400 NL/min; the second bottom blowing flow rate is 800-1000 NL/min.

Optionally, the oxidant comprises at least one of oxide balls or iron scales; the oxidation ball comprises the following components in percentage by mass: tfe > 65%, CaO > 35%, SiO2 < 5% and other unavoidable impurities.

Optionally, the calculation formula of the first feeding amount is as follows:

optionally, the slagging material comprises sintering lime and fluorite, wherein the sintering lime is 4-6kg/t and the fluorite is 1-2.5kg/t in mass.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

according to the method provided by the embodiment of the application, if the content of phosphorus exceeds the standard, the related processes of converter smelting and/or refining furnace smelting are controlled to dephosphorize; the low temperature of the molten steel in the converter steel sample is low, the molten steel content is high, the molten steel is controlled by fully utilizing the related processes of converter bottom blowing stirring and sintered lime addition, and phosphorus existing in phosphorus element or phosphide in the molten steel is oxidized into P₂O₅And enters into the slag. P₂O₅Is acid oxide, the sintering lime and the basic oxide in the slag generate phosphate, the phosphorus is removed by the auxiliary oxidation of the converter bottom blowing stirring process, and the reaction product P₂O₅Is not very stable and can only be removed by entering slag. The smelting of the refining furnace comprises the step of solidifying slag of the refining furnace, increasing the melting point of the slag and enabling the oxidized phosphorus to form stable phosphorus in the slagPhosphate to achieve the dephosphorization effect.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

Fig. 1 is a schematic flow chart of a dephosphorization method for emergency remediation according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

A dephosphorising process for emergency remediation, as shown in figure 1, comprising the steps of:

the application provides a dephosphorization method for emergency remediation, as shown in figure 1, the method comprises the following steps:

s1, obtaining the content of each chemical component in molten steel for converter steelmaking;

s2, judging whether the phosphorus content exceeds the standard or not according to the content of the chemical components and the standard phosphorus content;

s3, if yes, carrying out dephosphorization control on converter smelting and/or dephosphorization control on refining furnace smelting according to the standard phosphorus content, and carrying out emergency remedial dephosphorization;

the dephosphorization control of the converter smelting comprises bottom blowing and alkalinity control after the converter smelting is carried out;

the refining furnace smelting comprises refining furnace slag solidification.

The method in the embodiment of the application is suitable for the field of production and smelting of low-phosphorus or ultra-low-phosphorus steel without deoxidation during converter tapping, and is used for high emergency treatment of abnormal phosphorus and ultra-low phosphorus of oxygen-containing steel.

In the embodiment of the application, the comprehensive dephosphorization rate can reach 30-55%, the average dephosphorization rate is 44%, the demanganization rate is about 20% when the method is implemented aiming at the steel grade with the phosphorus content of more than or equal to 0.01% and completely meeting the requirement.

Aiming at the variety with high phosphorus content of the unoxidized steel after the tapping of the converter, the bottom blowing stirring system is used behind the converter to supplement slag, so that the slag reaches high alkalinity, and the slag steel reaction reaches a certain dephosphorization effect. The LF furnace process is refined similarly, when the oxygen content is insufficient, an oxidation ball or an iron scale is matched, and the slag melting capability of an electrode is assisted, so that efficient dephosphorization is achieved; and at the end of treatment, the sticky slag is solidified to prevent rephosphorization reaction after subsequent deoxidation.

In the embodiment of the application, the phosphorus content in the slag is removed by slagging off conventionally, and rephosphorization is prevented from occurring after deoxidation, so that the phosphorus content in the molten steel is increased again.

In the embodiment of the application, the gas for bottom blowing stirring of the converter can be inert gas or nitrogen gas and the like, and the reason for controlling the gas flow to be 1200-1500 NL/min is that the molten steel is fully stirred under the conditions of low temperature and oxygen carrying, the slag steel reaction is carried out, the top slag can be fully melted, and the beneficial effect of dephosphorization is achieved.

As an optional embodiment, the gas flow rate of bottom blowing after the converter is 1200-1500 NL/min, and the time is 5-8 min.

As an alternative embodiment, the controlling the alkalinity comprises adding sintered lime; the particle size of the sintering lime is 5-35 mm, and the addition amount of the sintering lime is 3-5 kg/t.

The chemical composition of the sintering lime comprises SiO in percentage by mass₂: 0-2.5%, CaO: 80-85%, MgO: < 10% and S: less than 0.05%. Wherein, SiO₂Represents the mass fraction of silica, and CaO represents the mass fraction of calcium oxide; the grain size of the sintering lime is 5mm-35 mm.

In the embodiment of the application, the chemical composition of the control sintering lime can guarantee the content of effective calcium oxide, the basicity of the furnace slag is controlled, the beneficial effect of the dephosphorization condition is achieved, the particle size of the control sintering lime can effectively guarantee that the sintering lime is rapidly melted into slag, the excellent effect of promoting dephosphorization is achieved, and if the particle size is too large, the melting speed is slow and the adverse effect of furnace slag incrustation is caused.

The reason for controlling the addition amount of the sintering lime is to promote slagging, and the excessive addition amount can cause the slag to be too thin and the dephosphorized product to be not remained in the slag, thereby having the adverse effect on dephosphorization, and the excessive addition amount can cause the slag not to be completely melted or the melting effect is not good, the fluidity is poor, and the adverse effect on dephosphorization is caused.

In the application, after the sintering lime is melted, the reason for stirring the molten steel and the top slag is to promote the increase of the contact area of the steel and the slag, so that the dephosphorization reaction is carried out, and the reaction product floats upwards to enter the top slag.

In the embodiment of the application, the components are reported back in the converter tapping process or after tapping is finished, and when the phosphorus content exceeds the standard: the method can be used for immediately opening the converter and then forcibly stirring, and the flow of the bottom-blown stirring gas of the converter can be controlled to be 1200-1500 NL/min; meanwhile, adding 3-5 kg/t of small-granularity sintering lime, and controlling the target alkalinity to be 3.3-5.3; and (3) strongly stirring for 5-8min on the premise of determining the melting of the small-granularity sintering lime.

As an alternative embodiment, the increasing the viscosity of the slag comprises:

obtaining a first molten steel temperature for refining molten steel and a first target temperature of molten steel required by a refining furnace;

performing first temperature rise on the refined molten steel and controlling the bottom blowing gas flow of the molten steel according to the first molten steel temperature and the first target temperature;

and when the terminal temperature of the first temperature rise reaches the first target temperature, adding 1-2 kg/t of the sintering lime to obtain the slag with the melting point of 1420-1440 ℃.

In the embodiment of the application, the alkalinity is controlled to solidify slag by controlling the temperature of the molten steel and the flow of bottom blowing gas, so that the viscosity of the slag is increased, the dephosphorization effect is ensured, and the rephosphorization after subsequent deoxidation is prevented.

As an alternative embodiment, the refining furnace smelting further comprises the following steps:

obtaining a first oxygen content of molten steel entering a refining furnace and a target oxygen content of the refining furnace;

judging whether an oxidant needs to be added to the incoming molten steel or not according to the first oxygen content and the target oxygen content;

if yes, calculating a first feeding amount of the oxidant according to the first oxygen content, the target oxygen content and the oxygen content of the oxidant;

adding the oxidant according to the first feeding amount to obtain oxygenated molten steel;

performing bottom blowing on the oxygen-enriched molten steel in a refining furnace at a first bottom blowing flow rate, adding slag melting materials in batches to a target alkalinity of 5-7, performing electrode slag melting, and performing second temperature rise on the oxygen-enriched molten steel;

obtaining a second target temperature of molten steel required by the refining furnace;

when the terminal temperature of the second temperature rise reaches a second target temperature, stopping electrode slagging, and performing bottom blowing of the refining furnace at a second bottom blowing flow rate;

and (3) continuously and forcibly stirring the oxygen-enriched steel for 4-6min at the gas flow rate of 800-1000 Nl/min to obtain the dephosphorized molten steel.

In the embodiment of the application, the slag melting material is added in batches to the target alkalinity of 5-7, wherein the slag melting material comprises small-particle-size sintered lime of 3-4 kg/t and fluorite of 100-150 kg which are added in batches, and electrode slag melting is started; 3) adding small-granularity sintering lime of 2-3 kg/t at intervals of 3min, wherein the target alkalinity is 5-7.

In the embodiment of the application, the relative low temperature and oxygen-containing condition of the molten steel are utilized, the bottom blowing stirring system is fully used, the slag is supplemented, the slag achieves high alkalinity, and the slag steel reaction achieves a certain dephosphorization effect. When the oxygen content is insufficient, the dephosphorization agent is matched with an oxidation ball or an iron scale, and assists the electrode in slagging capacity, so that the effect of efficient dephosphorization is achieved.

As an alternative embodiment, the target oxygen content is 500-600 ppm; the first bottom blowing flow rate is 300-400 NL/min; the second bottom blowing flow rate is 800-1000 NL/min.

As an alternative embodiment, the oxidizing agent comprises oxide spheres or scales; the oxidant comprises oxide balls or iron scales; the oxidation ball comprises the following components in percentage by mass: tfe > 65%, CaO > 35%, SiO2 < 5% and other unavoidable impurities.

As an alternative embodiment, the first charge is calculated by the following formula:

wherein the yield in the embodiment of the application can be 10%, the conventional yield can be 0.8-0.2, and the target oxygen content, the first oxygen content and the Tfe content are all in unit of mass percent.

In the embodiment of the application, the oxygen content is controlled, so that the phosphorus in the molten steel is oxidized, and the dephosphorization effect is achieved.

As an alternative to the above-described embodiment,

in the embodiment of the application, the first bottom blowing flow is 300-400 NL/min, has the beneficial effects of rapid slagging, uniform temperature and uniform components, and after slagging is stopped, the second bottom blowing flow is 800-1000 NL/min, has the advantages of stirring molten steel and top slag, promoting the increase of the contact area of steel and slag, carrying out dephosphorization reaction, and enabling a reaction product to float upwards to enter the top slag.

As an optional embodiment, the slagging material comprises sintered lime and fluorite, wherein the sintered lime is 4-6kg/t and the fluorite has a mass of 1-2.5 kg/t.

In the examples of the present application, the oxidation of phosphorus is carried out at the slag steel interface in order to generate P₂O₅The slag is stably present in the slag and the slag,the basicity of the steelmaking slag must be increased, i.e. P must be increased₂O₅The compound 3CaO & P stably bonded with CaO₂O₅And 4 CaO. P₂O₅. Thus, the dephosphorization reaction is a reaction carried out at the steel-slag interface.

Example 1

The method for dephosphorization is adopted, and dephosphorization is controlled in the tapping process or after tapping: the components behind the converter are generally reported back in the tapping process of the converter or after tapping is finished, and when the phosphorus content is found to exceed the standard: 1) immediately opening the furnace, then forcibly stirring, and controlling the flow to be 1200-1500 NL/min; 2) meanwhile, adding 3-5 kg/t of small-granularity sintering lime, and controlling the target alkalinity to be 3.3-5.3; 3) and (3) strongly stirring for 5-8min on the premise of determining the melting of the small-granularity sintering lime.

Controlling a refining LF furnace: refining in a refining furnace by adopting a conventional method, and then solidifying slag: 1) double-path bottom blowing and single-path bottom blowing flow rates are 200-300 NL/min, and molten steel is rapidly heated according to the RH required temperature; 2) and (4) adjusting the bottom blowing flow to 100NL/min after the temperature rise is finished, and adding 1-2 kg/t of small-granularity sintering lime for slag solidification.

Example 2

And (3) converter dephosphorization control: the components behind the converter are generally reported back in the tapping process of the converter or after tapping is finished, and when the phosphorus content is found to exceed the standard: 1) immediately opening the furnace, then forcibly stirring, and controlling the flow to be 1200-1500 NL/min; 2) meanwhile, adding 3-5 kg/t of small-granularity sintering lime, and controlling the target alkalinity to be 3.3-5.3; 3) and (3) strongly stirring for 5-8min on the premise of determining the melting of the small-granularity sintering lime.

Dephosphorization control of a refining LF furnace: 1) blowing the molten steel to open the slag surface after the molten steel enters the station, and carrying out oxygen determination operation, when the oxygen activity is less than 400ppm, adding an oxidation ball or an iron scale for oxygenation, wherein the target is 500-600ppm, and the oxygen activity is more than or equal to 400ppm, and directly carrying out the next operation; 2) double-path bottom blowing and single-path bottom blowing flow rates are 300-400 NL/min, small-particle-size sintering lime of 3-4 kg/t and fluorite of 100-150 kg are added in a first batch, and electrode slagging is started; 3) adding small-granularity sintering lime of 2-3 kg/t at intervals of 3min, wherein the target alkalinity is 5-7, melting slag by an electrode, and heating to 1610 ℃; 4) and stopping using the electrode after the target temperature is reached, adjusting the bottom blowing flow to 800-1000 Nl/min, and continuously and forcibly stirring for 5 min. Controlling solid slag of a refining LF furnace: 1) double-path bottom blowing and single-path bottom blowing flow rates are 200-300 NL/min, and molten steel is rapidly heated according to the RH required temperature; 2) and (4) adjusting the bottom blowing flow to 100NL/min after the temperature rise is finished, and adding 1-2 kg/t of small-granularity sintering lime for slag solidification.

Comparative example 1

The deoxidation is not carried out after the furnace, the RH light treatment (or decarburization treatment) process is carried out after the LF furnace is simply heated, and the rest is the same as the example 1.

Comparative example 2

The furnace is not deoxidized, and the subsequent process adopts an LF furnace to directly enter an RH light treatment (or decarburization treatment) process, and the rest is the same as the example 1.

The phosphorus content was measured by direct-reading spectroscopy method, standard GB/T4336-2016, and the results are shown in Table 1.

Table 1, results of testing each parameter in examples and comparative examples.

As can be seen from Table 1, the dephosphorization rate in the comparative example is lower than that in the example, and the phosphorus content is 0.0075%, which shows that the dephosphorization rate is very low or even no dephosphorization is realized without the method; the comprehensive dephosphorization rate can reach 30-55%, the average dephosphorization rate is 44%, and the demanganization rate of about 20% is obtained by the method aiming at the steel grade with the phosphorus content more than or equal to 0.01%. Meanwhile, the method also supports the oxygen-containing steel abnormal phosphorus high-emergency treatment and ultra-low phosphorus variety development and storage technology.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Reference to E is only a specific embodiment of the invention to enable those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.