METHOD OF REMOVING OIL FROM A MIXTURE OF TOOL STEEL SWARF

GRANULAR MATERIAL AND OIL

BACKGROUND

1. Technical Field:

This application relates to a method of removing oil from a mixture of tool steel swarf granular material and oil.

2. Background Information:

This application relates to the process conditions in utilizing supercritical carbon dioxide (SCCO ₂ ) for substantial removal of residual cutting fluids, either oils and/or water, and at least partial removal of other contaminants from industrial grindings of tool steels that may be contaminated with aqueous and/or oil-based residual contaminates. The contaminant liquid can be recycled for reuse, and the solids can be recycled or remelted in the smelting process for reuse. If the contaminants are not removed, they present an environmental hazard when they are land filled or incinerated.

Supercritical carbon dioxide is carbon dioxide that is at a temperature and a pressure greater than Tr = 1 and Pr =1. (Tr is T/Tc where T is the present temperature of the supercritical carbon dioxide and Tc is the critical temperature. Pr is P/Pc where P is the present pressure of the supercritical carbon dioxide and Pc is the critical pressure.) Tc, the critical temperature for carbon dioxide (CO ₂ ), is 31.1 degrees Celsius ( ⁰ C), or 304.1 degrees Kelvin (K), and Pc is 73 atmospheres (atm) or about 1073 pounds per square inch (PSI).

In more general terms, supercritical carbon dioxide refers to carbon dioxide that is in a fluid state while also being at or above both its critical temperature and pressure. Carbon dioxide usually behaves as a gas in air at standard temperature and pressure (STP) or as a solid called dry ice when frozen. If the temperature and pressure are both increased from standard temperature and pressure to be at or above the critical point for carbon dioxide, it can adopt properties midway between a gas and a liquid. More specifically, it behaves as a supercritical fluid above its critical temperature (31.1 °C) and critical pressure (73 atm), expanding to fill its container like a gas but with a density like that of a liquid. The supercritical fluid region of the phase diagram is defined as a temperature above the critical temperature (31.1 °C) to a pressure above

the critical pressure (73.8 bar or 1070 PSI).

SUMMARY

At least one possible embodiment of the present application teaches a method for the removal of oil from a mixture of granular material and oil using supercritical carbon dioxide. It was found, through experimentation, that the supercritical carbon dioxide extraction of high speed steel (HSS) grinding swarf can, in at least one possible embodiment of the present application, produce a solids high speed steel product with less than 5% (by weight) cutting oil. In at least one possible embodiment, there can be as low as 0.44% (by weight) oil in the extracted solids. A typical high speed steel swarf analysis is presented in Table A as follows:

Table A

The source of the aluminum oxide (alumina) is the grinding media. The principal source of the silicon dioxide (silica) is diatomaceous earth. This is often added for ease of filtration in trying to remove as much oil as possible from the swarf prior to land-filling.

The following represents the physical and chemical characteristics of HSS grinding swarf:

Solids:

-HSS - same composition as presented in Table A

-Particle sizes of swarf in Table A - median 400 mesh, or 37 micrometers (μ); particle size diameter (PSD), such as a mean diameter of the particles, from 10 micrometers to 300 micrometers; particles generally irregularly shaped and generally not spherical.

Contaminant: -A complex mixture of hydrocarbons

-Mixture, mostly paraffinic, but also some high MW oxy compounds

-Component analysis as follows:

-C ₆ to C ₁₀ = ~ 0.05% (by weight) -C ₁₀ to C ₁₆ = ~ 1.06% (by weight)

-C ₁₆ to C ₂₉ = ~ 4.0% (by weight) -C ₂₉ and higher = ~ 94.9% (by weight) Expressed differently, the component analysis is as follows:

-H ₁₄ C ₆ to H ₂₂ C ₁₀ = ~ 0.05% (by weight) -H ₂₂ C ₁₀ to H ₃₄ C ₁₆ = ~ 1.06% (by weight)

-H ₃₄ C ₁₆ to H ₆₀ C ₂₉ = ~ 4.0% (by weight) -H ₆₀ C ₂₉ and higher = ~ 94.9% (by weight).

In at least one possible embodiment of the present application, the particle sizes are primarily in the range of 10 to 100 micrometers. If a screen analysis of dried swarf is completed, usually at least 50% of the material by weight will pass through a standard 325 mesh screen. The screen opening for the 325 mesh screen is 45 micrometers. At least 98% of this material by weight will pass through a 80 mesh screen which has a screen opening of about 177 micrometers. In a screen analysis of a high speed steel swarf sample, oil was removed from a mixture of granular material and oil using supercritical carbon dioxide (CO ₂ ). The following Table B presents these results:

Table B

95

100

In this case, the median size (based on numbers of particles) was 39 micrometers.

105 Concerning non-metallic swarf components, diatomaceous earth is often used in such equipment as Coopermatic Filters to filter swarf from the grinding oil in manufacturing plants of the tool maker. Another product which is used in certain tool steel drill making plants that generate swarf is the Eagle Pitcher CELETOM FW 60. This application relates to the process configuration using supercritical carbon

110 dioxide in order to successfully remove as much as greater than 98% (by weight) of such contaminants from the feed solids, since the reuse of such "clean solids" is predicated on a contaminant level at approximately 0.5% to 2% (by weight). Using carbon dioxide as the working fluid or extraction solvent, at least one embodiment of the present application utilizes carbon dioxide cycling in and out of the supercritical

115 state to convert a metal waste by-product into a reusable liquid contaminant and substantially liquid contaminant-free solids, both of which can be reused with relatively small waste. The carbon dioxide may also be re-circulated and reused.

It is not necessarily desirable to produce a solids product with 0% contaminant (oil) since pure metals and/or alloys with high surface areas per weight, such as high

120 speed steel, can undergo rapid oxidation with air, especially for very high surface area fines. Not only can the temperature increases be large, there can or may be auto-

ignition, such as an explosion, of certain metals or alloys. Therefore, from a process point-of-view, removal of as much contaminant as possible should be promoted or maximized, while still leaving a minimum amount sufficient to suppress spontaneous

125 reaction during contact with air (oxygen) during the handling and transport of the purified solids.

In this regard, it is sufficient to leave approximately 0.5% to 2% (by weight) contaminant oil on high speed steel product. For other metals and alloys it may be sufficient to leave a different contaminant level, predicated by the oxidation chemistry

130 for each specific solid material in the cleansed product.

For extracted high speed steel swarf solids product, therefore, it may be sufficient to leave 0.5 to 2% (by weight) residual contaminant for handling and storage purposes, while re-melting such solids product can be easily and safely carried out.

At least one possible embodiment of the present application teaches a method of

135 removing oil from a mixture of granular material and oil, said method comprising the steps of: loading said mixture of granular material and oil into an extraction vessel; contacting said mixture with supercritical carbon dioxide at a pressure and at a temperature sufficient to remove a substantial portion of said oil from said mixture of granular material and oil; flowing a sufficient quantity of supercritical carbon dioxide

140 through said mixture for a sufficient period of time to yield a reduced oil content solids product and supercritical carbon dioxide containing oil from said mixture of granular material and oil; separating said solids product from the supercritical carbon dioxide containing oil from said solids product; and removing said solids product from the extraction vessel.

145 The above-discussed embodiments of the present invention will be described further hereinbelow. When the word "invention" or "embodiment of the invention" is used in this specification, the word "invention" or "embodiment of the invention" includes "inventions" or "embodiments of the invention", that is the plural of "invention" or "embodiment of the invention". By stating "invention" or "embodiment of the

150 invention", the Applicant does not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintains that this application may include more than one patentably and non-obviously distinct invention. The Applicant hereby asserts that the disclosure of this application

may include more than one invention, and, in the event that there is more than one 155 invention, that these inventions may be patentable and non-obvious one with respect to the other.

BRIEF DESCRIPTION OF THE DRAWINGS

At least one possible embodiment of the present application will be described by means of the accompanying drawings, in which:

160 Figure 1 is a graph showing results from supercritical carbon dioxide extraction of high speed steel grinding swarf;

Figure 2 is a diagram showing the process for carrying out the supercritical carbon dioxide extraction of high speed steel grinding swarf;

Figure 3 is a graph showing further results from supercritical carbon dioxide 165 extraction of high speed steel grinding swarf;

Figure 4 is a graph showing the percentage of oil extracted during a process of supercritical carbon dioxide extraction of high speed steel grinding swarf; and

Figure 5 is a graph showing the percentage of oil remaining after a process of supercritical carbon dioxide extraction of high speed steel grinding swarf has been 170 completed.

DESCRIPTION OF EMBODIMENT OR EMBODIMENTS The swarf, as analyzed in Tables A and B, was sent to Supercritical Solutions LLC, 2845 Rolling Green Place, Macungie, PA, 28062, to remove oil from the mixture of granular material and oil, and Table 1 shows the resulting data. In at least one possible 175 embodiment of the present application, a small sample of high speed steel swarf was loaded into a process development unit (PDU), brought to temperature, either by direct and/or indirect heat transfer, to 24 °C, and pressurized to 1700 PSI. The sample was extracted by passing pure subcritical carbon dioxide through the bed, continuously, over a two-hour (120 min) period. The sample of initial high speed steel swarf feed 180 contained approximately 12.4%, (by weight) contaminant oil. It should be noted that other samples of swarf could contain levels of contaminant oil other than 12.4%. Samples of treated swarf were taken and analyzed intermittently over the duration of the experiment. The effluent carbon dioxide from the bed was

depressurized, dropping-out the extracted oil in another, separate vessel. The samples 185 were analyzed every ten minutes, and after 120 minutes, the bed was depressurized, the contents emptied, and analyzed. The following Table 1 presents these results:

TABLE I PDU EXPERIMENTS

SCCO ₅ EXTRACTION OF HSS GRINDING SWARF

190

195

00

In Run 1 , the starting feed contained 12.4% oil, and the extracted sample of high speed steel product contained 10.6% (by weight) oil after a total processing residence time of 120 minutes. The oil removed from the feed was approximately 57.1 % (by 05 weight).

Another sample of high speed steel swarf was subjected to the process development unit and processed at supercritical carbon dioxide conditions, at 4300 PSI, and at 55C°, as noted in Run 2 in Table 1. The oil extracted was approximately 89.6% (by weight) at a residence time of 120 minutes. 10 In Run 3, the pressure was 4350 PSI, the temperature was 50 °C, and the amount of feed in the PDU was approximately one half the amount in Run 2. From Table 1 , it can be noted that the oil removal increased from 89.6% to 91.6% just by lowering the operating temperature 5 ^° C, from 55 to 50 ^° C. Again, the residence time was 120 minutes. 15 In Run 4, the pressure was 5000 PSI and temperature was 60 °C, and the oil removal was approximately 88.9% (by weight) after a residence time of 100 minutes.

In Run 5, the temperature was 64/65 °C and a pressure of 5000 PSI was employed. Run 5 produced an oil removal of approximately 95% (by weight). The

residence time was approximately 80 minutes. 220 Run 6 was carried out at a pressure of 8700 PSI and a temperature of 80 °C.

With a residence time of approximately 50 minutes, a 98.4% (by weight) removal of the contaminant oil was achieved.

The pressure was 9000 PSI at a temperature of 90 °C in Run 7. A sharp reduction in oil removal was found, down to 95.9% oil removal, and even with additional 225 variations of pressure up to 9200 PSI and temperature up to 1 10 ^° C (Runs 8, 9, and 10), the oil removal rates appeared to take a downturn.

Runs 7 through 1 1 were carried out at residence times of 55 - 85 minutes. For the Runs presented in Table 1 , not only were the conditions of temperature and pressure closely maintained, bed size and solvent to feed ratio (gms CO ₂ /gms 230 sample), also known as S/F, were closely controlled to obtain as high a contaminant removal as possible. In addition, residence time was carefully studied by taking samples during the Runs and analyzing the oil contents. These data are best summarized in Figure 1.

Using a continuous process development unit (PDU), carbon dioxide at the 235 conditions noted was passed through a bed (size noted) of high speed steel swarf and the contaminant oil removal (as % feed) was plotted against the cumulative amount of carbon dioxide being passed through the sample over the total residence time, as shown on Figure 1. Although end-point data are tabulated in Table 1 , at least 5 to 10 data points collected during the Runs were used to construct Curves A through K, as 240 shown in Figure 1. For clarity purposes, some are depicted in Figure 1 to elucidate the differences. The region between 8700 PSI and 9200 PSI represents the contaminant removal, as noted in Figure 1 for Curves G, H, and J. Note that the curve letters in

Figure 1 correspond to data points in the legend.

From the data in Table 1 and depicted in Figure 1 , it is concluded that an 245 optimum oil removal is achieved between 8700 PSI and 9000 PSI, or indeed at 8700

PSI. At 9000 and 9200 PSI, the oil removal decreased from a maximum of 98.4% to approximately 92% to 96%.

The process for carrying out the subject supercritical carbon dioxide substantial extraction of swarf can be generally depicted in Figures 2 and 3. Figure 2 is a diagram 250 depicting a process using either pure and/or recycled carbon dioxide. The pumps and

heat exchangers are designed to meet target Tr and Pr conditions at the prescribed solvent carbon dioxide to feed high speed steel ratios. The size of the "feed and product beds" are dependent on the physical characteristics of the feed and the production rate desired. The number of beds can also vary (from 2 as shown in Figure

255 2) depending on production rate desired.

The process depicted in Figure 2, two parallel stages, can be designed to yield 98+% oil contaminant removal from high speed steel, and other similar metallic waste products and other similar oil contaminants at extraction and desorption pressures of between 5000 PSI and 8700 PSI, and beyond, and at temperatures between 60° and

260 1 10 ⁹ C. At 5000 PSI and 65 °C, a 94.9% oil removal was achieved, and at 8700 PSI and 80 °C, a 98.4% oil removal was achieved (see Table 1 ). Therefore, it is possible 98+% oil removal could be achieved somewhere between 5000 PSI and 8700 PSI, and/or beyond. It should be understood that other process options besides two parallel stages may possibly be used in at least one possible embodiment.

265 Figure 3, used in conjunction with Figure 2, is intended to "simulate" the "cycle" for contaminant removal from high speed steel swarf. The solubility data (mole fraction oil in carbon dioxide) is estimated from the reference by J. Yau et al., J. Chem. Eng. Data, 38, 174 (1993) extrapolated to higher pressures and temperatures. The oil is assumed to be n-hexatriacontane (C ₃₆ ) and its solubility in supercritical carbon dioxide

270 used in Figure 3 to qualitatively depict the "cycle" used in Figure 2. Since the contaminant oil in high speed steel swarf is so complex, as will be described later, herein, most of it is C ₂₉ +. Therefore, solubility data in supercritical carbon dioxide for the highest MW normal paraffin found in the literature was used for Figure 3.

Therefore, Figure 3 is a solubility diagram with Points A through F depicted from

275 Figure 2. In Figure 3, three different cycles are shown with extraction pressures A of about 5000 psi, A' of about 7000 psi, and A" of about 9000 psi. When the effluent from the extractor is expanded through the separator to a lower pressure depicted by points B, the oil solubility decreases in the CO2 as noted on the ordinate axis of Figure 3. The amount of oil removed in each cycle is the difference in the ordinate between points A

280 and B and this difference increases as extraction pressure increases. The only points truly at, or close to, equilibrium are Points A and B and A', A", B', and B". Points C, D, E and F are far from equilibrium, but at pressures and temperatures depicted on Figure

3. Hence, the Points in any one cycle are represented by the Temperatures and Pressures, and additionally, for Points A, A', and A", and B, B', and B", the solubility of

285 oil in the supercritical carbon dioxide.

Figure 4 is a graph in which represents the percentage of oil extracted during Runs 1 -1 1 using the indicated pounds per square inch PSI pressure, as shown in Table 1. For instance, in Run 1 , 57.1 % of the oil was removed using 1700 PSI. Run 2 resulted in 89.6% of the oil being removed using 4300 PSI. 91.6% of the oil was

290 removed using 4350 PSI in Run 3. During Run 4, 88.9% of the oil was removed using 5000 PSI. Run 5 resulted in 94.9 % of the oil being removed using 5000 PSI. 98.4% of the oil was removed using 8700 PSI in Run 6. In Run 7, 95.9% of the oil was removed using 9000 PSI. Run 8 resulted in 92.9% of the oil being removed using 9000 PSI. 92.3% of the oil was removed using 9200 PSI in Run 9. Run 10 resulted in 94.9% of

295 the oil being removed in which 9200 PSI was used. Run 1 1 resulted in 96.2% of oil being removed using 9200 PSI.

Figure 5 is a graph, using information provided in Table 1 , to show the percentage of oil remaining after a process of supercritical carbon dioxide extraction of high speed steel grinding swarf has been completed. For instance, in Run 1 , 10.6% of

300 the oil remained after using 1700 PSI. Run 2 resulted in 2.92% of the oil remaining after using 4300 PSI. 91.6% of the oil remained after using 4350 PSI in Run 3. During Run 4, 3.26% of the oil remained after using 5000 PSI. Run 5 resulted in 1.52 % of the oil remaining after using 5000 PSI. 0.44% of the oil remained after using 8700 PSI in Run 6. In Run 7, 1.02% of the oil remained after using 9000 PSI. Run 8 resulted in

305 1.74% of the oil remaining after using 9000 PSI. 1 .84% of the oil remained after using 9200 PSI in Run 9. Run 10 resulted in 1.04% of the oil remaining after 9200 PSI was used. Run 1 1 resulted in 0.93% of oil remaining after using 9200 PSI.

Since high speed steel swarf is extremely dense (specific gravity (s.g.) of approximately 1.6), the sheer weight of the loaded process vessels at approximately

310 100 pounds per cubic feet can be substantial. In addition, loading, processing, and emptying such large vessels in residence times from 30 to 120 minutes can be a challenge for a large-tonnage plant. One possible option is to use a fewer number of large vessels with large weights filled and emptied in a longer period of cycle time, or another possible option is to use a larger number of smaller vessels with smaller

315 weights filled and emptied in a shorter period of cycle time. In at least one possible embodiment, the size and cycle time for handling such feed and product materials is selected to promote the supercritical carbon dioxide deep removal of this bulk contaminant oil.

It was determined that smaller vessels, in at least one possible embodiment, with

320 high length-to-diameter (UD) ratios (cylindrical) would be suitable. First, high L/D ratios can be achieved, more easily, for small vessels that result in providing turbulence and good mass transport during extraction and desorption in this cyclic process. Under these conditions of both high extraction and desorption rates, the potential is high to realize high oil removal rates of 90+%, up to 98+%. Second, for smaller vessels, the

325 volume of the vessels (V = _τ D ² L/4) can be chosen as a function of vessel length and diameter. Once general vessel volume and shape are chosen, a minimum residence time in the vessels should be maintained at the treat rates sufficient to obtain high bulk removal efficiencies.

In this type of high-pressure gas processing, it is possible to choose a "batch-

330 type" system or choose a "continuous-type" system. The batch systems can be used in parallel or in series, operated on a cyclic basis (at prescribed residence times), be sequentially loaded, processed, and unloaded, and yield a sufficient bulk removal efficiency. The "continuous-type" systems generally refer to a number of batch vessels, operated sequentially, with the supercritical carbon dioxide gas flow and the sequential

335 loading, processing, and unloading of the feed and product solids can be envisioned as counter current flow of the solids movement from feed to product with respect to the flow of the supercritical carbon dioxide. The directional loading, processing, and unloading is opposite to the flow of the supercritical carbon dioxide. This type of "continuous", counter current operation is generally referred to as continuous, counter

340 current, sequencing-batch operation. Therefore, when there are one or two batch stages, in series or parallel, the term "batch" tends to be used, and when there are three or more stages, if they operate in parallel flow to the supercritical carbon dioxide, the term "batch" is also used. However, when they operate in counter current flow of the solids to the supercritical carbon dioxide, we call them counter current "sequencing-

345 batch" simulating counter current flows of solid feed and solid product to the flow direction of the supercritical carbon dioxide. It should be understood that "continuous"

can also define a process in which the feed and solvent are fed continuously through a fixed system and the products are continuously removed.

For the conditions of Table 1 , in order to achieve high contaminant removals of

350 approximately 98%, fairly low residence times of approximately 50 minutes (as noted in Run 6 in Table 1 ) should be used. In at least one possible embodiment, the process can produce high oil removal levels, as well as produce an economical result. To obtain an economical result, a substantial amount of feed should be treated in a minimal time with a minimal amount of supercritical carbon dioxide (treat ratio).

355 It was found in this study that it was possible to operate at pressures up to

10,000 PSI and temperatures up to 80 - 100°C, to load, process, and unload vessels (requiring filling, pressurization, warm-up, processing, and depressurization, cool-down, and unloading) in cycle times less than 120 minutes, typically, 30 to 60 minutes; and, within 30 to 60 minutes, there was enough time to carry out the labor-related loading

360 and unloading of approximately 200 pounds of product solids. The labor related issues may or may not involve mechanical assistance, such as robotics, if desired. Therefore, with a solids density of approximately 100 pounds per cubic foot, at least one possible reactor size would be approximately 2 cubic feet based on extracted solids. Since the feed, according to at least one possible embodiment, can be up to 50% (by weight)

365 contaminated oil, with the added weight of the oil-laden feed solids, the extractor volume could be 2.5 cubic feet. It should also be noted that, according to at least one possible embodiment, the vessel is never or rarely totally full of feed, that is, there should be free-space in the vessels above/below the solids for equipment design and processing reasons.

370 In view of the above, extractor vessels may have substantial L/D's when the total volume per vessel is approximately 2.5 ft ³ . For example, an 8-inch inner diameter vessel would be approximately 7 feet long. For this L/D, good mass transfer characteristics can be obtained for the extraction and desorption part of the cycle with nominal bed pressure drops and treat ratios, and when processing in the supercritical

375 region, temperature and pressure control are often or sometimes critical to maintain purities.

For treat ratios of 5 to 30 gms CO ₂ /gm feed, for example, it can be calculated that sufficient mass transfer will exist in the 8-inch inner diameter vessels containing

beds of solids at slightly lower volumes. That is, in at least one possible embodiment, it

380 may be practiced to load the vessels with feed by using "baskets", which may be porous in construction, by lowering such baskets of feed into the vessel, extracting, and then raising and removing such baskets of products from the vessel. Since the baskets may contain feed up to 300 pounds, the baskets, in at least one possible embodiment, can be of metal or steel construction, or other material construction, sufficient to

385 withstand the weight load over many repetitive loading and unloading cycles. At least a part, if not most all, of the basket should be porous to the supercritical carbon dioxide for successful extraction and possibly desorption of the contaminant oil from the bed of solids.

The number of processing vessels (stages) and the sequence of operation, co-

390 current or counter current to the flow of supercritical carbon dioxide, should be selected for efficiency and economic reasons. For efficiency and economic reasons, counter current operations are usually or often more efficient and economical for large tonnage than co-current or batch operations for the specific separation defined and described herein. That is, the direction of filling and emptying the vessels is counter current to the

395 flow of supercritical carbon dioxide. On this basis, the number of vessels (stages) sufficient for a prescribed treat rate is directly a function of the production rate for the entire plant. For example, if a given 8-inch by 7-foot vessel will hold approximately 300 pounds of feed and if N is the number of vessels, then 300N pound of feed can be processed at, say, a residence time of 60 minutes. Therefore, according to at least one

400 possible embodiment, the production rate (based on the feed) can be calculated as follows: For N = 4, the plant can process 1200 pounds per hour, or approximately 14.4 tons per day (T/D) of feed; and for N = 3, the plant can process approximately 10.8 T/D. If the required residence time is 120 minutes, a similar calculation would show that for 3 stages, the production rate would be 5.4 T/D, and for 4 stages, the production rate

405 would be 7.2 T/D (based on feed flow).

One feature or aspect of an embodiment is believed at the time of the filing of this patent application to possibly reside broadly in a method of removing oil from a mixture of granular material and oil, comprising high speed steel swarf, said method comprising the steps of: loading said mixture of granular material and oil into an

410 extraction vessel; contacting said mixture with supercritical carbon dioxide at a pressure

greater than 4300 psi and at a temperature sufficient to remove a substantial portion of said oil from said mixture of granular material and oil; flowing a sufficient quantity of supercritical carbon dioxide through said mixture for a sufficient period of time to yield a reduced oil content solids product and supercritical carbon dioxide containing oil from

415 said mixture of granular material and oil; separating said solids product from the supercritical carbon dioxide containing oil from said solids product; and removing said solids product from the extraction vessel.

Another feature or aspect of an embodiment is believed at the time of the filing of this patent application to possibly reside broadly in a method of removing oil from a

420 mixture of granular material and oil, comprising high speed steel swarf, said method comprising the steps of: loading said mixture of granular material and oil into an extraction vessel; contacting said mixture with supercritical carbon dioxide at a pressure and at a temperature sufficient to remove a substantial portion of said oil from said mixture of granular material and oil; flowing a sufficient quantity of supercritical carbon

425 dioxide through said mixture for a sufficient period of time to yield a reduced oil content solids product and supercritical carbon dioxide containing oil from said mixture of granular material and oil; separating said solids product from the supercritical carbon dioxide containing oil from said solids product; and removing said solids product from the extraction vessel.

430 Yet another feature or aspect of an embodiment is believed at the time of the filing of this patent application to possibly reside broadly in a method of removing oil from swarf, said method comprising the steps of: loading said swarf into an extraction vessel; contacting said swarf with supercritical carbon dioxide at a pressure greater than 4300 psi and at a temperature sufficient to remove a substantial portion of said oil

435 from said swarf; flowing a sufficient quantity of supercritical carbon dioxide through said swarf for a sufficient period of time to yield a reduced oil content solids product and supercritical carbon dioxide containing oil from said swarf; separating said solids product from the supercritical carbon dioxide containing oil from said solids product; and removing said solids product from the extraction vessel.

440 Still another feature or aspect of an embodiment is believed at the time of the filing of this patent application to possibly reside broadly in a method of removing oil from swarf, said method comprising the steps of: loading said swarf into an extraction

vessel; contacting said swarf with supercritical carbon dioxide at a pressure and at a temperature sufficient to remove a substantial portion of said oil from said swarf; flowing

445 a sufficient quantity of supercritical carbon dioxide through said swarf for a sufficient period of time to yield a reduced oil content solids product and supercritical carbon dioxide containing oil from said swarf; separating said solids product from the supercritical carbon dioxide containing oil from said solids product; and removing said solids product from the extraction vessel.

450 The components disclosed in the various publications, disclosed or incorporated by reference herein, may possibly be used in possible embodiments of the present invention, as well as equivalents thereof.

U.S. provisional patent application 60/942,883, filed on June 8, 2007, having inventors Robert J. BELTZ, Eugene J. GRESKOVICH, and Rodger MARENTIS,

455 Attorney Docket No. NHL-KAL-03-PROV, and title "METHOD FOR DEEP

EXTRACTION OF CONTAMINANTS FROM GRINDING SWARFS AND SIMILAR MATERIALS USING SUPERCRITICAL CARBON DIOXIDE" is hereby incorporated by reference as if set forth in its entirety herein.

The appended drawings in their entirety, including all dimensions, proportions

460 and/or shapes in at least one embodiment of the invention, are accurate and are hereby included by reference into this specification.

U.S. provisional patent application 60/942,748, filed on June 8, 2007, having inventors Robert J. BELTZ, Eugene J. GRESKOVICH, and Rodger MARENTIS, Attorney Docket No. NHL-KAL-04-PROV, and title "DEEP EXTRACTION OF

465 GRINDING SWARFS AND SIMILAR MATERIALS USING SUPERCRITICAL CARBON DIOXIDE" is hereby incorporated by reference as if set forth in its entirety herein.

All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if more than one embodiment is described herein.

470 U.S. provisional patent application 60/942,759, filed on June 8, 2007, having inventors Rodger MARENTIS, Robert J. BELTZ, and Eugene J. GRESKOVICH, Attorney Docket No. NHL-KAL-05-PROV, and title "METHOD FOR NEARLY COMPLETE EXTRACTION OF GRINDING SWARFS AND SIMILAR MATERIALS USING SUPERCRITICAL CARBON DIOXIDE" is hereby incorporated by reference as

475 if set forth in its entirety herein.

All of the patents, patent applications and publications recited herein, and in the

Declaration attached hereto, are hereby incorporated by reference as if set forth in their entirety herein.

It will be understood that any or all examples of patents, published patent 480 applications, and other documents which are included in this application and including those which are referred to in paragraphs which state "Some examples of ... which may possibly be used in at least one possible embodiment of the present application..." may possibly not be used or useable in any one or more or any embodiments of the application. 485 The sentence immediately above relates to patents, published patent applications and other documents either incorporated by reference or not incorporated by reference.

All of the references and documents, cited in any of the documents cited herein, are hereby incorporated by reference as if set forth in their entirety herein. All of the 490 documents cited herein, referred to in the immediately preceding sentence, include all of the patents, patent applications and publications cited anywhere in the present application.

The details in the patents, patent applications and publications may be considered to be incorporable, at applicant's option, into the claims during prosecution 495 as further limitations in the claims to patentably distinguish any amended claims from any applied prior art.

The embodiments of the invention described herein above in the context of the preferred embodiments are not to be taken as limiting the embodiments of the invention to all of the provided details thereof, since modifications and variations thereof may be 500 made without departing from the spirit and scope of the embodiments of the invention.