阅读说明：本技术 一种磷石膏中共晶磷的分离处理方法 (Separation treatment method of eutectic phosphorus in phosphogypsum ) 是由 任利 张军兴 陈颜龙 刘福峰 谢东 安延营 李杨 张合军 郭超 于 2021-07-28 设计创作，主要内容包括：本发明提供了一种磷石膏中共晶磷的分离处理方法,包括以下步骤：a)将待处理的磷石膏煅烧成半水磷石膏；b)将步骤a)得到的半水磷石膏加入微沸状态的硫酸溶液中搅拌,得到混合浆液；c)将步骤b)得到的混合浆液加水稀释,再经抽滤,得到滤饼；d)将步骤c)得到的滤饼依次经洗涤、干燥,得到分离共晶磷后的磷石膏。与现有技术相比,本发明提供的分离处理方法采用特定工艺步骤,利用二水石膏在转变成半水石膏过程中留下的水分子通道,将热的硫酸溶液通过水分子通道进入磷石膏晶格,溶解晶格中的共晶磷,再通过稀释后的稀硫酸溶液萃取溶解下来的共晶磷,最后将半水石膏再水化生成二水石膏,实现磷石膏中共晶磷的有效萃取及分离。(The invention provides a separation treatment method of eutectic phosphorus in phosphogypsum, which comprises the following steps: a) calcining phosphogypsum to be treated into semi-hydrated phosphogypsum; b) adding the semi-hydrated phosphogypsum obtained in the step a) into a sulfuric acid solution in a slightly boiling state, and stirring to obtain mixed slurry; c) diluting the mixed slurry obtained in the step b) by adding water, and performing suction filtration to obtain a filter cake; d) washing and drying the filter cake obtained in the step c) in sequence to obtain the phosphogypsum with the eutectic phosphorus separated. Compared with the prior art, the separation treatment method provided by the invention adopts specific process steps, utilizes the water molecule channel left in the process of converting the dihydrate gypsum into the semi-hydrated gypsum, leads hot sulfuric acid solution to enter the crystal lattice of the phosphogypsum through the water molecule channel to dissolve the eutectic phosphorus in the crystal lattice, extracts the dissolved eutectic phosphorus through diluted dilute sulfuric acid solution, and finally rehydrates the semi-hydrated gypsum to generate the dihydrate gypsum, thereby realizing the effective extraction and separation of the eutectic phosphorus in the phosphogypsum.)

1. A separation treatment method of eutectic phosphorus in phosphogypsum comprises the following steps:

a) calcining phosphogypsum to be treated into semi-hydrated phosphogypsum;

b) adding the semi-hydrated phosphogypsum obtained in the step a) into a sulfuric acid solution in a slightly boiling state, and stirring to obtain mixed slurry;

c) diluting the mixed slurry obtained in the step b) by adding water, and performing suction filtration to obtain a filter cake;

d) washing and drying the filter cake obtained in the step c) in sequence to obtain the phosphogypsum with the eutectic phosphorus separated.

2. The separation process according to claim 1, characterized in that the phosphogypsum to be treated in step a) is phosphogypsum dihydrate; the grade of the dihydrate phosphogypsum is 80-99%, the pH value is 1.0-7.5, and the whiteness is 19-75%.

3. The separation treatment method according to claim 1, wherein the calcination in step a) is carried out at a temperature of 150 ℃ to 200 ℃ for 60min to 180 min.

4. The separation process of claim 1, wherein the water of crystallization of the phosphogypsum hemihydrate in step a) is 4.5-6.0%.

5. The separation treatment method according to claim 1, wherein the concentration of the sulfuric acid solution in the slightly boiling state in step b) is 1 to 50% by mass, and the temperature of the sulfuric acid solution is controlled to 90 to 100 ℃ to maintain the slightly boiling state.

6. The separation treatment method according to claim 1, characterized in that the mass ratio of the semi-hydrated phosphogypsum to the slightly boiling sulfuric acid solution in the step b) is (3-12): 1.

7. the separation treatment method according to claim 1, wherein the rotation speed of the stirring in the step b) is 180 to 1600r/min, and the time is 20 to 180 min.

8. The separation treatment method according to claim 1, wherein the dilution with water in step c) is specifically:

and adding water into the mixed slurry for diluting to ensure that the mass concentration of the sulfuric acid solution is 0.1-5%, and stirring for 40-60 min at the speed of 600-1200 r/min.

9. The separation treatment method according to claim 1, wherein the washing process in step d) is carried out by washing with water until the pH value of the filtrate is 6.5-7.5.

10. The separation treatment method according to claim 1, wherein the drying temperature in step d) is 45 to 100 ℃ and the drying time is 40 to 180 min.

Technical Field

The invention relates to the technical field of phosphogypsum treatment, in particular to a separation treatment method of eutectic phosphorus in phosphogypsum.

Background

The phosphogypsum is the largest byproduct of phosphate compound fertilizer produced by phosphate ore through a wet-process phosphoric acid process, and has large stockpiling amount and low utilization rate. The phosphogypsum has strong acidity and high impurity content; in particular, the eutectic phosphorus in the phosphogypsum exists in the crystal lattice of the phosphogypsum and is symbiotic with calcium sulfate. During the hydration process of the building gypsum, the eutectic phosphorus is dissolved out from crystal lattices and becomes soluble HPO₄ ^2-The ionized phosphate radical is further combined with calcium ions to generate insoluble calcium phosphate salt, which prevents further hydration of gypsum and reduces the strength of a hardened body. Therefore, the removal of the eutectic phosphorus in phosphogypsum is a technical problem to be solved urgently by the technical personnel in the field; however, the traditional modes of water washing, lime neutralization, organic matter flotation, high-temperature calcination and the like can not effectively remove the eutectic phosphorus in the phosphogypsum.

Disclosure of Invention

In view of this, the present invention aims to provide a separation treatment method of eutectic phosphorus in phosphogypsum, which can effectively remove the impurities of the eutectic phosphorus in the phosphogypsum.

The invention provides a separation treatment method of eutectic phosphorus in phosphogypsum, which comprises the following steps:

a) calcining phosphogypsum to be treated into semi-hydrated phosphogypsum;

b) adding the semi-hydrated phosphogypsum obtained in the step a) into a sulfuric acid solution in a slightly boiling state, and stirring to obtain mixed slurry;

c) diluting the mixed slurry obtained in the step b) by adding water, and performing suction filtration to obtain a filter cake;

d) washing and drying the filter cake obtained in the step c) in sequence to obtain the phosphogypsum with the eutectic phosphorus separated.

Preferably, the phosphogypsum to be treated in the step a) is dihydrate phosphogypsum; the grade of the dihydrate phosphogypsum is 80-99%, the pH value is 1.0-7.5, and the whiteness is 19-75%.

Preferably, the calcining temperature in the step a) is 150-200 ℃ and the time is 60-180 min.

Preferably, the content of crystal water in the semi-hydrated phosphogypsum in the step a) is 4.5-6.0%.

Preferably, the mass concentration of the sulfuric acid solution in the slightly boiling state in the step b) is 1 to 50%, and the slightly boiling state is maintained by controlling the temperature of the sulfuric acid solution to 90 to 100 ℃.

Preferably, the mass ratio of the semi-hydrated phosphogypsum to the slightly boiling sulfuric acid solution in the step b) is (3-12): 1.

preferably, the rotating speed of the stirring in the step b) is 180 r/min-1600 r/min, and the time is 20 min-180 min.

Preferably, the process of diluting with water in step c) specifically comprises:

and adding water into the mixed slurry for diluting to ensure that the mass concentration of the sulfuric acid solution is 0.1-5%, and stirring for 40-60 min at the speed of 600-1200 r/min.

Preferably, the washing process in the step d) adopts water to wash until the pH value of the filtrate is 6.5-7.5.

Preferably, the drying temperature in the step d) is 45-100 ℃, and the drying time is 40-180 min.

The invention provides a separation treatment method of eutectic phosphorus in phosphogypsum, which comprises the following steps: a) calcining phosphogypsum to be treated into semi-hydrated phosphogypsum; b) adding the semi-hydrated phosphogypsum obtained in the step a) into a sulfuric acid solution in a slightly boiling state, and stirring to obtain mixed slurry; c) diluting the mixed slurry obtained in the step b) by adding water, and performing suction filtration to obtain a filter cake; d) washing and drying the filter cake obtained in the step c) in sequence to obtain the phosphogypsum with the eutectic phosphorus separated. Compared with the prior art, the separation treatment method provided by the invention adopts specific process steps, utilizes the water molecule channel left in the process of converting the dihydrate gypsum into the semi-hydrated gypsum, leads hot sulfuric acid solution to enter the crystal lattice of the phosphogypsum through the water molecule channel to dissolve the eutectic phosphorus in the crystal lattice, extracts the dissolved eutectic phosphorus through diluted dilute sulfuric acid solution, and finally rehydrates the semi-hydrated gypsum to generate the dihydrate gypsum, thereby realizing the effective extraction and separation of the eutectic phosphorus in the phosphogypsum.

In addition, the sulfuric acid solution in the whole process of the separation treatment method provided by the invention can be recycled after being filtered and concentrated, and other impurities in the phosphogypsum can be effectively removed besides the eutectic phosphorus.

Drawings

FIG. 1 is an infrared characteristic spectrum of co-crystal phosphorus in phosphogypsum obtained by the separation treatment method provided by the phosphogypsum raw paste, examples 1-3 and comparative example 1.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 invention.

The invention provides a separation treatment method of eutectic phosphorus in phosphogypsum, which comprises the following steps:

a) calcining phosphogypsum to be treated into semi-hydrated phosphogypsum;

b) adding the semi-hydrated phosphogypsum obtained in the step a) into a sulfuric acid solution in a slightly boiling state, and stirring to obtain mixed slurry;

c) diluting the mixed slurry obtained in the step b) by adding water, and performing suction filtration to obtain a filter cake;

d) washing and drying the filter cake obtained in the step c) in sequence to obtain the phosphogypsum with the eutectic phosphorus separated.

The invention firstly calcines the phosphogypsum to be treated into semi-hydrated phosphogypsum. In the present invention, the phosphogypsum to be treated is preferably dihydrate phosphogypsum; either fresh phosphogypsum or washed phosphogypsum, well known to the person skilled in the art, can be used. In the invention, the grade of the dihydrate phosphogypsum is preferably 80-99%, and more preferably 85-95%; the pH value of the dihydrate phosphogypsum is preferably 1.0-7.5, and more preferably 1.5-5.5; the whiteness of the dihydrate phosphogypsum is preferably 19-75%, and more preferably 19.5-60%.

In the invention, the calcination temperature is preferably 150-200 ℃, and more preferably 160-180 ℃; the calcination time is preferably 60 to 180min, and more preferably 90 to 150 min.

In the invention, the crystal water content of the calcined hemihydrate phosphogypsum is preferably 4.5-6.0%, more preferably 4.8-5.7%; the whiteness of the calcined semi-hydrated phosphogypsum is correspondingly improved.

After the semi-hydrated phosphogypsum is obtained, the obtained semi-hydrated phosphogypsum is added into a sulfuric acid solution in a slightly boiling state and stirred to obtain mixed slurry. In the present invention, the mass concentration of the sulfuric acid solution in the slightly boiling state is preferably 1% to 50%, more preferably 10% to 20%; the temperature of the sulfuric acid solution is controlled to be 90-100 ℃, and the micro-boiling state is maintained.

In the invention, the mass ratio of the semi-hydrated phosphogypsum to the slightly boiling sulfuric acid solution is preferably (3-12): 1, more preferably (5-10): 1.

in the invention, the rotating speed of the stirring is preferably 180 r/min-1600 r/min, and more preferably 800 r/min-1200 r/min; the stirring time is preferably 20min to 180min, and more preferably 25min to 45 min. The invention adopts the process of adding the obtained semi-hydrated phosphogypsum into a slightly boiling sulfuric acid solution and stirring, and aims to utilize a water molecule channel left in the process of converting the dihydrate gypsum into the semi-hydrated gypsum and make the hot sulfuric acid solution enter a phosphogypsum crystal lattice through the water molecule channel so as to dissolve eutectic phosphorus in the crystal lattice, namely a decomposition process.

After the mixed slurry is obtained, the obtained mixed slurry is diluted by adding water and is subjected to suction filtration to obtain a filter cake. The method adopts the steps that the eutectic phosphorus dissolved in the diluted dilute sulfuric acid solution is extracted, namely the extraction process; and separating the sulfuric acid solution for extracting the eutectic phosphorus from the phosphogypsum by suction filtration, namely a separation process.

In the invention, the process of adding water for dilution is preferably specifically as follows:

adding water into the mixed slurry for diluting to ensure that the mass concentration of the sulfuric acid solution is 0.1-5%, and stirring for 40-60 min at 600-1200 r/min;

more preferably:

and adding water into the mixed slurry for diluting to ensure that the mass concentration of the sulfuric acid solution is 2-3%, and stirring for 45min at the speed of 700-800 r/min. In the invention, the dilution times by adding water are limited according to the mass concentration requirement of the diluted sulfuric acid solution; the mass concentration of the diluted sulfuric acid solution is the mass concentration of the dilute sulfuric acid solution for extracting the dissolved eutectic phosphorus. Therefore, the invention realizes the effect that the sulfuric acid solution simultaneously participates in dissolving the eutectic phosphorus in the crystal lattice and extracts the dissolved eutectic phosphorus; and through the subsequent suction filtration step, the sulfuric acid solution for extracting the eutectic phosphorus can be separated, and meanwhile, the sulfuric acid solution used in the whole process can be recycled after being filtered and concentrated.

The process of the suction filtration is not particularly limited, and the technical scheme of the suction filtration known to a person skilled in the art can be adopted.

After the filter cake is obtained, the obtained filter cake is washed and dried in sequence to obtain the phosphogypsum with separated eutectic phosphorus, namely the phosphogypsum without the eutectic phosphorus. In the invention, the washing process preferably adopts water to wash until the pH value of the filtrate is 6.5-7.5, and more preferably 6.8-7.2.

In the invention, the drying temperature is preferably 45-100 ℃, and more preferably 60-90 ℃; the drying time is preferably 40min to 180min, and more preferably 50min to 120 min.

The present invention adopts the above process to rehydrate the hemihydrate gypsum to produce dihydrate gypsum, i.e. the rehydration process.

The separation treatment method provided by the invention adopts specific process steps, utilizes water molecule channels left in the process of converting the dihydrate gypsum into the semi-hydrated gypsum, makes hot sulfuric acid solution enter phosphogypsum crystal lattices through the water molecule channels to dissolve the eutectic phosphorus in the crystal lattices, extracts the dissolved eutectic phosphorus through diluted dilute sulfuric acid solution, and finally rehydrates the semi-hydrated gypsum to generate the dihydrate gypsum, thereby realizing the effective extraction and separation of the eutectic phosphorus in the phosphogypsum; the test of the total phosphorus and soluble phosphorus content in the phosphogypsum adopts a phosphomolybdic acid quinoline gravimetric method JC/T2073 plus 2011 method for measuring phosphorus and fluorine in the phosphogypsum, and after the content of the total phosphorus and the content of soluble phosphorus in the phosphogypsum are detected, the difference between the total phosphorus and the soluble phosphorus is used as the content of eutectic phosphorus in the phosphogypsum. Besides the eutectic phosphorus, other impurities in the phosphogypsum can be effectively removed.

The invention provides a separation treatment method of eutectic phosphorus in phosphogypsum, which comprises the following steps: a) calcining phosphogypsum to be treated into semi-hydrated phosphogypsum; b) adding the semi-hydrated phosphogypsum obtained in the step a) into a sulfuric acid solution in a slightly boiling state, and stirring to obtain mixed slurry; c) diluting the mixed slurry obtained in the step b) by adding water, and performing suction filtration to obtain a filter cake; d) washing and drying the filter cake obtained in the step c) in sequence to obtain the phosphogypsum with the eutectic phosphorus separated. Compared with the prior art, the separation treatment method provided by the invention adopts specific process steps, utilizes the water molecule channel left in the process of converting the dihydrate gypsum into the semi-hydrated gypsum, leads hot sulfuric acid solution to enter the crystal lattice of the phosphogypsum through the water molecule channel to dissolve the eutectic phosphorus in the crystal lattice, extracts the dissolved eutectic phosphorus through diluted dilute sulfuric acid solution, and finally rehydrates the semi-hydrated gypsum to generate the dihydrate gypsum, thereby realizing the effective extraction and separation of the eutectic phosphorus in the phosphogypsum.

In addition, the sulfuric acid solution in the whole process of the separation treatment method provided by the invention can be recycled after being filtered and concentrated, and other impurities in the phosphogypsum can be effectively removed besides the eutectic phosphorus.

To further illustrate the present invention, the following examples are provided for illustration. The specific parameters of phosphogypsum to be treated used in the following examples of the invention are as follows: the crystal water content of the phosphogypsum is 19.6 percent, the grade is 85.1 percent, the pH value is 2.03, and the whiteness is 19.7 percent.

Example 1

(1) And (3) calcining: calcining phosphogypsum to be treated at 170 ℃ for 120min to obtain semi-hydrated phosphogypsum; the crystal water content is 5.6%, and the whiteness is 40.9%.

(2) And (3) decomposition: preparing a sulfuric acid solution with the mass concentration of 15%, controlling the temperature of the sulfuric acid solution to be 100 ℃, and keeping the slightly boiling state; slowly adding the semi-hydrated phosphogypsum obtained in the step (1) into the hot sulfuric acid solution and stirring at 1000r/min, wherein the mass ratio of the sulfuric acid solution to the treated semi-hydrated phosphogypsum is 1: and 6, stirring for 30min to obtain mixed slurry.

(3) Extraction and separation: and (3) adding water into the mixed slurry obtained in the step (2) to dilute by 6 times so that the mass concentration of the sulfuric acid solution is 2.5%, stirring at 800r/min for 45min, and performing suction filtration to obtain a filter cake.

(4) Rehydration: washing the filter cake obtained in the step (3) with water until the pH value of the filtrate is 7.1, and then drying the filter cake at 75 ℃ (60min) to obtain phosphogypsum after eutectic phosphorus is separated; the total phosphorus and soluble phosphorus content in phosphogypsum were measured by the phosphomolybdic acid quinoline gravimetric method, and the results are shown in table 1.

Example 2

(1) And (3) calcining: calcining phosphogypsum to be treated at 160 ℃ for 150min to obtain semi-hydrated phosphogypsum; the crystal water content is 5.7%, and the whiteness is 38.2%.

(2) And (3) decomposition: preparing a sulfuric acid solution with the mass concentration of 10%, controlling the temperature of the sulfuric acid solution to be 100 ℃, and keeping the slightly boiling state; slowly adding the semi-hydrated phosphogypsum obtained in the step (1) into the hot sulfuric acid solution and stirring at 800r/min, wherein the mass ratio of the sulfuric acid solution to the treated semi-hydrated phosphogypsum is 1: stirring for 45min to obtain mixed slurry.

(3) Extraction and separation: and (3) adding water into the mixed slurry obtained in the step (2) to dilute by 4 times, so that the mass concentration of the sulfuric acid solution is 2.5%, stirring at 800r/min for 45min, and performing suction filtration to obtain a filter cake.

(4) Rehydration: washing the filter cake obtained in the step (3) with water until the pH value of the filtrate is 6.8, and then drying the filter cake at 90 ℃ (50min) to obtain the phosphogypsum after eutectic phosphorus is separated; the total phosphorus and soluble phosphorus content in phosphogypsum were measured by the phosphomolybdic acid quinoline gravimetric method, and the results are shown in table 1.

Example 3

(1) And (3) calcining: calcining phosphogypsum to be treated at 180 ℃ for 90min to obtain semi-hydrated phosphogypsum; the crystal water content is 4.8%, and the whiteness is 41.5%.

(2) And (3) decomposition: preparing a 17% sulfuric acid solution, controlling the temperature of the sulfuric acid solution to be 100 ℃, and keeping a slightly boiling state; slowly adding the semi-hydrated phosphogypsum obtained in the step (1) into the hot sulfuric acid solution and stirring at 1200r/min, wherein the mass ratio of the sulfuric acid solution to the treated semi-hydrated phosphogypsum is 1: and 5, stirring for 25min to obtain mixed slurry.

(3) Extraction and separation: and (3) adding water into the mixed slurry obtained in the step (2) to dilute the mixed slurry by 6.8 times so that the mass concentration of the sulfuric acid solution is 2.5%, stirring the mixed slurry at the speed of 700r/min for 45min, and performing suction filtration to obtain a filter cake.

(4) Rehydration: washing the filter cake obtained in the step (3) with water until the pH value of the filtrate is 7.2, and then drying the filter cake at 60 ℃ (120min) to obtain the phosphogypsum after eutectic phosphorus is separated; the total phosphorus and soluble phosphorus content in phosphogypsum were measured by the phosphomolybdic acid quinoline gravimetric method, and the results are shown in table 1.

Comparative example 1

(1) And (3) decomposition: preparing a sulfuric acid solution with the mass concentration of 15%, controlling the temperature of the sulfuric acid solution to be 100 ℃, and keeping the slightly boiling state; slowly adding phosphogypsum to be treated (dihydrate phosphogypsum) into the hot sulfuric acid solution and stirring at 1000r/min, wherein the mass ratio of the sulfuric acid solution to the treated hemihydrate phosphogypsum is 1: and 6, stirring for 30min to obtain mixed slurry.

(2) Extraction and separation: and (2) adding water into the mixed slurry obtained in the step (1) to dilute by 6 times so that the mass concentration of the sulfuric acid solution is 2.5%, stirring for 45min at 700/min, and performing suction filtration to obtain a filter cake.

(3) Rehydration: washing the filter cake obtained in the step (2) with water until the pH value of the filtrate is 7.1, and then drying the filter cake at 75 ℃ (60min) to obtain phosphogypsum after eutectic phosphorus is separated; the total phosphorus and soluble phosphorus content in phosphogypsum were measured by the phosphomolybdic acid quinoline gravimetric method, and the results are shown in table 1.

Table 1 data of contents of total phosphorus, soluble phosphorus and eutectic phosphorus in phosphogypsum and raw phosphogypsum paste obtained by the separation treatment methods provided in examples 1 to 3 and comparative example 1

The infrared characteristic spectrogram of the eutectic phosphorus in the phosphogypsum obtained by the separation treatment method provided by the phosphogypsum raw paste, the embodiments 1-3 and the comparative example 1 is shown in figure 1.

Other properties of the phosphogypsum and the raw phosphogypsum paste obtained by the separation treatment methods provided in the examples 1-3 and the comparative example 1 are detected, and the results are shown in table 2.

Table 2. phosphogypsum and phosphogypsum raw paste obtained by the separation treatment methods provided in examples 1-3 and comparative example 1 of the invention

Sample (I)	Whiteness/%	SO3/％	Grade/% (CaSO)4·2H2O)
				Example 1	50.75	41.64	89.1
EXAMPLE 2	50.37	42.07	90.0
				EXAMPLE 3	61.56	46.02	98.5
Comparative example 1	26.18	41.19	88.2
				Phosphogypsum raw paste	19.70	39.76	85.1

As can be seen from the data in table 1, the total phosphorus content of the untreated phosphogypsum is 1.01%, the soluble phosphorus content is 0.06%, the eutectic phosphorus content is 0.95%; after the separation treatment method provided by the embodiments 1 to 3, the total phosphorus content in the phosphogypsum is 0 to 0.009%, the soluble phosphorus content is 0, the content of eutectic phosphorus is close to 0, and the higher the concentration of the sulfuric acid solution is, the better the removal effect of phosphorus impurities is. The characteristic peak of the eutectic phosphorus was not detected in the infrared spectrum shown in fig. 1. It can be seen from example 1 and comparative example 1 that the dihydrate gypsum was treated directly with the hot sulfuric acid solution and was not able to remove the eutectic phosphorus. In the process of converting the dihydrate gypsum into the semi-hydrated gypsum, water molecule channels are left, the hot sulfuric acid solution dissolves the eutectic phosphorus in the gypsum crystal lattices through the water molecule channels, in the extraction process, the semi-hydrated gypsum is hydrolyzed into the dihydrate gypsum in the dilute sulfuric acid solution, and the eutectic phosphorus is dissolved in the liquid phase, thereby completing the separation process.

From the data in table 2, after the separation treatment method provided in the embodiments 1 to 3, not only the eutectic phosphorus in the phosphogypsum is effectively removed, but also the grade of the phosphogypsum is improved and the whiteness is increased, which indicates that other impurities in the phosphogypsum are also effectively removed.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present 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.