TW200950927A - Process for separating and recovering the suspending fluids contained in exhausted slurries from the machining of silicon - Google Patents

Abstract

A process for the complete separation of the suspending fluid from the solid components container in an exhausted slurry, either abrasive or not, coming from the cutting operation or other mechanical working of materials of monocrystalline or polycrystalline silicon, or of quartz or other ceramic materials, or contained in the sludge obtained from a previous centrifugation of such exhausted suspension. The process involves the immediate separation of all the solid components contained in the slurry through one or more stages, in counter-current, of extraction of the suspending fluid with a suitable solvent or mixture of solvents, followed by sedimentation of the suspension diluted with the solvent, and by recovery by overflow of the surnatant, consisting of the mixture of suspending fluid and solvent. The residual phase left from the last recovery by overflow undergoes a final separation by filtration of all the solids present, while from the mixture of suspending fluid and solvent obtained from the first recovery by overflow the suspending fluid is recovered by distillation.

Description

200950927 IX. INSTRUCTIONS OF THE INVENTION: TECHNICAL FIELD The present invention relates to a method for separating and recovering a suspension fluid contained in a discharge sludge from a mechanical processing of a crucible. More specifically, the invention relates to a method by which a suspension fluid is discharged into a suspension suspension from a single crystal or polycrystalline germanium material, or a quartz or other ceramic material by means of a device necessary for carrying out the method. The contained solid component 'is completely separated from the solid component (whether or not it is abrasive) contained in the mud obtained by, for example, the pre-centrifugation operation of such a discharge suspension. [Prior Art] As known in the manufacture of parts used in the field of electronics and photovoltaic energy, thin-film (wafer) or square thin-walled slices are used. Obtained by cutting a single crystal slab (semiconductor) or polycrystalline slab "brick" (solar application) perpendicular to its axis. Generally speaking, this type of slicing is performed by a wire saw or a cutting machine. In a wire saw and a cutting machine, a metal wire having a considerable length and appropriate mechanical resistance is wound in a system of rollers and reels. The wire is in contact with and moves with the bismuth in a position perpendicular to the length of the bismuth in the position where the cutting is to be performed. At the same time, the slurry (grinding mud) containing the ground fine particles or granules is supplied to the cutting wire and the bismuth ingot. Or the area of contact between the “stones.” The conventional abrasive slurry used with metal wire ore to cut crushed, quartz or other ceramic materials consists of a suspension fluid, a lubricating fluid or a cooling fluid, 6 200950927 eg with high molecular weight Mineral oil or water-soluble organic liquid, especially polyethylene glycol (PEG), in which suspended particles of appropriate hardness and substantially tantalum carbide (SiC) are suspended. Using, for example, alumina (A12〇3) Other abrasive suspensions prepared from cerium carbide abrasives are used in other non-cut boring machining operations, such as lapping or "back-grinding," The final film thickness reduction. This type of operation is carried out by a sander after cutting. The sander is mainly composed of two absolutely flat and rounded horizontal cast iron plates which can overlap and rotate in opposite directions. A stone slice from the cutting operation is placed between the iron plates, and the mud gather of the abrasive particles is fed thereto. This clay buildup typically consists of a suspension fluid, a mixture of suitable millbases, typically oxidized, and commercial suspension additives. During the above-mentioned machining operations, that is, cutting, polishing, and back-grinding, a portion of the abrasive fine particles lose their effective characteristics for the process, and at the same time the abrasive slurry becomes rich in the stone bond or Shi Xi's sliced, called, particulate matter 'is rich in fine iron particulate matter from the cutting line or from the plate. As the amount of fine particulate matter increases, the abrasive slurry loses its mechanical properties: the efficiency of the slicing operation and the quality of the product are reduced. This causes the mud transfer to be ineffective and must be discarded and replaced with fresh grinding mud. The discharged mud is sent to recover the reusable ingredients, that is, the abrasive fines having a size larger than a certain critical value and the suspended fluid used by the slurry itself. If the latter (mainly mineral oil or, for example, a fresh organic fluid) is effectively purified to avoid the suspension of fine particles of the metal residue and the stone, and the abrasive fine particles which are not reused by the 200950927 method, This process has not changed during the process' so it can be completely reused in this process. It is conventionally used for recovery by first separating the suspended fluid from the solids contained therein by a filtration or centrifugation step, and then recovering the milled fines which are still maintained at the minimum size required for the cutting operation. However, especially in the case of oil-based mud, the high viscosity of the discharged suspension and the presence of fine particles such as cerium abrasive and iron make the filtration step quite difficult in an inexpensive manner, sometimes even not May be implemented. On the other hand, the selective operation consisting of the centrifugation step can only obtain some thick products (generally referred to as "in the mud". However, it still contains a large amount of suspended liquid. Considering in more detail the suspension present in the slurry. Fluids and solids' For suspensions in mechanical applications such as electronics and photovoltaics, the suspension fluids are mainly oil-based or PEG-based (where PEG has different molecular weights). Is a mineral oil with linear chain Cio-C:24 or a synthetic oil with aromatic chain Cl8_c26, with a small amount of additives added. 'These additives are unique for each application and have a special formula'. It is not known to recover the treatment mud which separates the fine particles from the suspension agent. These additives together with the fine particles of the fine particles and fine particles of other metals may make the direct filtration step unsuitable or at least become difficult to apply. The solid portion of the powder generally consists of the following components: • Carbonization with a grain size greater than 5em矽 (SiC) or other abrasives, such as diamond or alumina (A丨2〇3)', in the processing of single crystal 矽 or polycrystalline 2009 slices 200950927 or 矽 ingot processing can be used as abrasives; Carbonized sic or other abrasives (also known as fine particles) having a particle size of less than 5 centimeters, which cannot be reused as abrasives in the above-mentioned machining operations; • generally have a stone eve of less than 5 mm Scrap (Si), which is machined from Shi Xiqian; • Iron scrap (Fe) with a size less than 5"m, which comes from the tools (cutting lines or polishing plates) used in machining. Several techniques have been proposed for the patent document on grinding muds produced by the machining operations for handling broken slices. However, in addition to recovering the liquid components, these techniques are mainly directed to the size and chemistry of solids present in the discharged mud. Separation by nature. In essence, it can be found that the results of the processes used are quite complicated. In the case of oil-based abrasive muds and water-soluble organic liquids. In the case of mud, the proposed technique combines the following basic operations in various ways: a) In particular, by diluting with a solvent or by heating, the viscosity of the discharged loach is initially reduced, thereby enabling further operation. Handling the mud; b) by means of a fishing size differentiation step, for example by a centrifugation step or by passing the mud through a hydrocyclone (h-Call (a kind of static separator for solid particles carried in liquid A) Separating the recyclable fines by the action of centrifugal force; c) separating the recyclable fines by treating the discharged mud by a solvent which is miscible with the base suspension fluid of the mud; 9 200950927 d Filtering out the phase of the liquid produced by the grinding fine separation step; e) distilling the liquid helium mixture of the solvent, and cooling the fluid constituting the filtrate; 0 drying the reusable abrasive fine particles. It will be understood from the following with reference to some examples of prior art solutions that all of the latest technologies used have the primary purpose of two coexistences as described below and are implemented from the discharge mud rather than from The indifference product begins: (1) separating a portion of the abrasive material that can still be reused from a portion of the abrasive material that is no longer reusable and processing waste such as dream and metal; (2) recovering the suspended fluid, and The solvent used to reduce the viscosity of the discharged mud or to separate the recyclable abrasive. European Patent Application No. EP-A-7863 No. 7 (Shin-Etsu Handotai Co., Ltd.) discloses a system for re-using oil as a main type of discharge grinding mud, in which water is first added in order to reduce the viscosity of the discharged mud. The sludge is discharged and the resulting mixture is fed to a hydrocyclone, thereby separating the reusable abrasive fines. As is known, in a hydrocyclone, the feed to be treated is fed into the apparatus at high speed and tangentially from the top end such that centrifugal forces push the heavier particles toward the outer wall of the container. Moving in a helix, the heavier particles are then collected in the conical bottom of the container (undercurrent) while the purified liquid exits (overflow) from the central conduit at the tip. In the solution proposed in the above document, the hydrocyclone spill contains oily suspension fluid, water and all solid particles that have not been picked up by the hydrocyclone. This spill is then separated by 200950927 by the centrifugation step. In two phases. This operation produces an oily phase that can be reused in the cutting process, water that can be reused during the initial draining dilution phase, and residual suspension that is sent to the waste treatment plant with solids to be discarded. According to the teachings of the above documents, when an undesired fine powder is recovered and reused, the powder tends to accumulate in the abrasive slurry. The same applies to oily muds recovered from centrifugation operations, which inevitably contain traces of fine solid particles that return to the cutting operation and accumulate in the system. & A method of using a large amount of solvent, but with a different procedure and purpose than the present invention, is disclosed in International Patent Application No. WO 1/4343393 (Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung eV), which relates to a Process method. The stage of operation is substantially the same as that disclosed in the patent document of EP-A-786 317, but in this case the auxiliary treatment fluid added during the preliminary stage is selected to reduce the stickiness of the discharged mud (in the previous In the case of an oil-based abrasive slurry, the auxiliary treatment fluid is water) such that it is miscible with the suspension liquid of the abrasive slurry. Therefore, in the case of an oil-based abrasive slurry, the diluent fluid is selected from a lipophilic solvent (for example, n-hexane or n-heptane), and in the case of a water-soluble slurry, hydrophilic and hydrophobic can be used. Amphiphilic s〇ivent (for example, C. Since in this case, the added liquid can be dissolved in the suspension fluid, the suspension obtained after separating the reusable abrasive fine particles must be suspended. The necessary filtration of the fine solids is followed by distillation to facilitate recovery of the suspension fluid and solvent. However, in this way, since the lower boiling component, ie the solvent, is separated by distillation according to 11 200950927, the recyclable abrasives are The particles remaining in the suspension after separation are still present in the recovered suspension fluid, and when the latter is reused, the particles gradually build up. European Patent No. EP 0791385 (Shin-Etsu Handotai Co. et al.) Revealing a method similar to the above two methods for separating and reusing the discharged grinding mud, but mainly intended for water In the case of a solvent-based mud, the first operation is also made up of a suspension to be treated by dilution with water, thereby reducing its viscosity and then treating it by wet sorting. Mixture for separating reusable abrasive fines. The preferred apparatus is also a hydrocyclone. This method differs from the two systems described above in relation to: liquid suspension obtained from the overflow of a hydrocyclone Recycling and separation treatment. In order to help separate the suspended solids, add the coagulant to the liquid suspension, and then all accept the distillation' to recover the water, which is the lightest part, and the water can be reversed. It is reused as the initial dilution of the discharge mud. The mixture of the water slurry, suspended solids and coagulant is subjected to solid state liquid separation treatment, preferably through a centrifugation step, thereby obtaining the solid residue to be discarded on the one hand. On the other hand, water-soluble mud is obtained. After further processing, this water-soluble clay can be reused in the cutting step in these further processes, Dispersing agent is added to adjust the viscosity of the slurry. As for the purity of the recovered suspension fluid fed back to the cutting step, the same considerations made by the two previous methods can be applied to this situation. US Patent No. 6, 〇1〇 , 〇ι〇 (Elektr〇schmelzwerk 12 200950927

Kempten) proposes to treat the discharge of the grinding mud by means of a different recycling scheme than that which has been thought so far. In this case, the entire solid component is dried in the first stage, e.g., by evaporation or spray drying involving vacuuming the discharged mud to some extent. Most of the vaporized liquid system consisting of the suspended fluid of the abrasive slurry condenses and can be reused for the cutting operation. The technique of fully drying the suspended solids in the mud, circulating the evaporation and recondensing the suspended fluid, causes the suspension fluid to be subjected to thermal stress, thereby degrading it. If the suspended fluid is oil, the structure of the concentrate may differ from the structure of the new oil; however, if the liquid is polyethylene glycol (pEG), this method may not work. This is because the temperature required for evaporation. Oh, so PEG with high molecular weight cannot evaporate without damaging its structure. One method disclosed in European Patent No. EP 0968801 (MEMC Electronic Materials and Garbo Servizi) is directed to the regeneration of a water-soluble discharge grinding slurry in which the discharged abrasive material is first heated to reduce its viscosity' and then by filtration. And subject to initial separation. Thus, a purifying liquid is produced which is composed mostly of a cutting fluid having a trace amount of powder and agglomerates of wet powder, and the wet powder contains almost all solids suspended in the discharged mud in addition to a small amount of cutting fluid. Then, the wet powder is diluted with water' and separated by a hydrocyclone, thereby producing a part of the larger size of the fine particles (underflow) and the overflow (overfi〇w) part of the spill. The fraction consists of fine particles suspended in water mixed with a smaller amount of suspended fluid. The spillage from the top of the hydrocyclone is filtered to recover the aqueous fluid, which can be used to dilute the wet powder prior to the hydrocyclone separation process. EP 0 968 801 ^ (MEMC Electronic Materials and Garb. Servizi) discloses a method for the regeneration of water-soluble discharged grinding mud, wherein the discharged abrasive is first heated to reduce its viscosity and then subjected to over-cracking. Initial separation. This produces a purifying liquid which is mostly composed of a cutting fluid having a trace amount of powder and agglomerates of fish powder which, in addition to a small amount of cutting fluid, also contains almost all solids suspended in the discharged mud. These wet powders are then diluted with water and separated by a hydrocyclone, thereby producing a portion of the fine particles (dark stream) and a portion of the spill having substantially larger dimensions of reusable abrasive fines. In part, the spill is composed of fine particles suspended in water (abrasives, tantalum powders and metal powders that cannot be reused) and a smaller amount of suspended fluid. The 4 wounds containing the abrasive fines are dried by the furnace while the overflow from the top of the hydrocyclone is filtered to recover the aqueous fluid used to dilute the wet powder prior to the hydrocyclone separation process, and substantially A solid residue of powder and metal. The suspended liquid recovered from the first filtration of the hot exhaust mud is removed by further means of a transitional operation, and then it is sent to a cutting operation. In addition to having to heat the sludge in advance to reduce its stickiness, another disadvantage of the above method that cannot be ignored is that in order to perform a /7 step in the hydrocyclone, a considerable amount of water must be added to the previous filtration. 'House powder. Also, care must be taken because cutting the 200950927 fluid after the previous filtration will leave the solids and lose a small amount of cutting fluid, thus reducing the recovery of the suspended fluid. Another method for treating discharged slurry having a water-soluble liquid matrix, in particular polyethylene glycol PEG, is disclosed in International Patent Application No. WO 02/09661 1 (MEMC Electronic Materials and Garbo)

In Servizi), the discharge mud is first divided into a solid portion and a liquid portion which is not completely solid-free by means of filtration (the filtration cake containing the residual suspension liquid in the suspension fluid is washed in water, and then The sodium hydroxide solution is treated to dissolve and remove fine particles of cerium. The filtrate obtained from the above operation is treated with an acid leaching agent, thereby dissolving and removing the metal powder, thereby A mixture of fine particles of reusable and non-reusable abrasive materials is obtained by subsequent cleaning of the solid portion. The recovery yield of the suspension is now negatively affected by the loss of a portion of the suspension in the previous filtration. Finally 'International Patent Application Bulletin No. W〇2〇〇6/137〇98 (Sic Holding GmbH) also relates to a method for recovering all the recoverable components of the discharged slurry, in particular not only the recovery of PEG-based suspension fluids, but also Recovering abrasive grains of carbon carbide of appropriate size while treating ruthenium and iron particles. The above method involves centrifugation The first solid/liquid separation is used to transfer the concentrated portion to a section for recovering the fine particles. The section contains the entire series of hydrocyclones and one for filtration and chemical treatment. The subsequent equipment of the granules, while the liquid portion containing most of the particles and the suspended fluid is treated in a section for recovering the suspended fluid. Such a recycling process is solved according to one of the solutions 15 200950927 through subsequent operations In practice, these subsequent operations include: filtering 'adding an assay solution to the purified solution, microfiltration, neutralizing the purified fluid obtained, distilling a small amount of water added to the process, filtering and recovering the anhydrous PEG for reuse. In another solution proposed in the same patent document for the recovery of suspending agents, in addition to treatment with an alkaline solution and subsequent neutralization, it involves the treatment of a cationic resin followed by treatment with an anion resin. The above method is directed to the overall recovery of all reusable ingredients of the discharged mud' and, for this reason, From the point of view of the necessary equipment, ❹ this method is quite complicated. Generally speaking, for the purpose of recovering suspended fluids, all of the above prior art have some of the following disadvantages: * In particular, the recovery yield of the mud component of the suspended fluid is low; The complexity of the process, or the need for an excessively large number of operations, otherwise the processing takes a long time; • The solvent used for the separation step is consumed in a large amount. ❹ [Summary] According to the above, this SUMMARY OF THE INVENTION It is an object of the invention to provide a method for treating a discharge mud produced by machining from Shixia or other similar processing procedures of quartz or ceramic materials, which can be recovered in an inexpensive and elastic manner. The suspended fluid is included to allow repeated use of the suspension fluid in the preparation of fresh mud cracks. Such an approach can be used as an alternative and convenient alternative to the complex procedure for separating suspended fluids described above. This method should advantageously be applied to a discharged sludge which is abrasive regardless of whether it is applied, and which can be applied to the centrifugally separated or agriculturally thick product (i.e., sludge) obtained from the above slurry, that is, derived from the pretreatment stage. The product, in general, still has a considerable amount of suspending fluid, for example up to as much. a Under the preliminary research framework related to the present invention, the observed krypton was examined by scanning electron microscopy (SEM) for the gj body contained in the mechanically discharged sludge (4) from the crucible, confirming that the diameter is usually less than ^2. "Miao granules of m" When small diamond particles having a diameter of from 3 to 40 " m ] are present, for example, in the presence of carbonized stone, the small particles surround the above-mentioned abrasive particles. Therefore, the particles having a larger diameter are substantially composed of tantalum carbide, have a prism shape and a diameter of 5/zm or more; and, in some cases, the occurrence of particle oligomers is found. In contrast, the stone granules are more spherical and result in agglomerates containing sizes between 2 and 5 " m. It has also been observed that when a suspension containing the above solid mixture (for example, an oil-based suspension) is treated with a solvent which is compatible with the oil itself, a new suspension can be obtained, which is more diluted in terms of solid content. Has a viscosity that is detectable below the starting value. Viscosity varies as a function of the solvent used and the dilution ratio of the suspension fluid to the solvent. When the diluted suspension is allowed to settle freely, the equilibrium velocity (final velocity) of particle settling is determined by Stokes Law. The latter is effective for Reynolds number <1 This example is because the liquid during settling has a velocity equal to zero): 17 200950927

Ut = 18μ where ut is the final speed, D is the diameter of the solid particles involved during settling, and Ps and P are the density of the solid and liquid, respectively (in this case the oil/PEG/solvent mixture density), g is Gravity acceleration, and μ is the viscosity of the oil/pEG/solvent mixture. Finally, K is a factor that takes into account the spherical shape of the particle diameter D. Generally, this factor is 丨 for bismuth particles and 0.81 for strontium carbide particles. ❹ According to Stork's Law, the following may be observed: a) The equilibrium or final velocity of equal solids content and equal content of oil/pEG/solvent mixture is proportional to the square of the particle diameter; therefore, larger particles It tends to settle faster; b) at the same dilution level of oil/PEG/solvent present, this and the final speed, but 匕) grain...fine 3). . Carbonized carbide particles (Ug/cm3) will be larger than sand particles and p Ecm'. Solvents must be selected among these products. The molecules include the desired affinity and viscosity for oil and PEG. ° '(4) also has the lowest possible ease and economical convenience. The purpose of the present invention is to extract by a simple solid, which is t, suspended, and all appropriate solvents present in the fluid and suspension. In the case where it is not possible to carry out the filtration, all the solid components of β1 are separated by the flow system immediately in combination with the Φ 'discharge slurry composed of PEG or PEG'. Then, 诂, the solid components are separated and classified by chemical species through the other method. According to the present invention, the knife separation of the suspension fluid is carried out by pumping the suspension fluid through a suitable solvent through one or more successive steps carried out in a countercurrent manner, each step being followed by sedimentation of the suspension for an appropriate period of time and by suspension of fluid and solvent. The overflow of the supernatant consisting of the mixture is recovered. The suspension stream system with the largest amount of suspended fluid extracted by the initial recovery of the spill is sent to recover the suspended fluid by distillation, while the slurry remaining in the final sediment is made of solid powder dispersed in the solvent. Composition, which has a very small amount of residual suspending fluid; this slurry is diluted with an additional amount of solvent and subjected to final filtration after extraction to separate all of the solids present. The filter cake produced by the filtration is washed, and thus the solvent and the last trace suspended liquid can be recovered, and then the filter cake is dried. Therefore, the product obtained by treating the discharged mud or its thick sludge by the method proposed above comprises the following: a) The slurry is sent to the re-used slurry to substantially suspend the fluid, and the recovery yield is greater than 99%; nb) contains all the solids in the mud. A dry powder of the ingredients; possible chemical separation or size classification of the ingredients of the powder may be carried out by techniques not within the scope of this month. Therefore, the present invention specifically proposes a method for separating and recovering a suspended liquid contained in a thick portion of the discharged mud or which is discharged from the muddy soil. 'Whether or not the abrasive sludge is discharged from the stone material 2. Cutting operation or other mechanical processing of quartz and other ceramic materials, the method comprises the following operations: 19 200950927 Dilution, t ^ Solvent or solvent mixture which can be mixed with the suspended liquid is carried out from the above discharged mud / thick portion Extracting the suspension fluid; b) diluting the suspension by liquid-solid tiller; knife "treating" - the operation of the supernatant obtained before the recovery - surna, ocean fluid and solvent or a mixture of solvent mixtures; which can be selectively repeated in one or two additional stages by a series of operations a)_e) suspended in the first stage;

The suspension fluid is recovered by separating the solvent or solvent mixture from the supernatant obtained in the first stage of operation c) by steaming; the supernatant obtained from the operation e) of each of the possible additional stages described above is Feeding to the previous stage of the extraction operation a); ticking the residual phase of the recovery operation from the last stage with the above solvent or solvent mixture, and filtering the obtained diluted suspension, thereby producing a discharged sludge/concentration A portion of substantially all of the solid filter cake that was originally present.

Preferably, after the filtration of operation e), the following operations can be carried out: 0 washing the filter cake' recovering the solvent or solvent mixture with a trace amount of the suspension fluid; g) drying the filter cake produced by the other operation. With reference to certain exemplary embodiments of the claimed method of the present invention, the liquid flow system obtained from the filtration of operation e) is fed to the final stage of the extraction operation a) according to the multi-stage method of feeding in the reverse flow. . Operation of liquid-solid separation b) permeable to the density difference of 20 centrifugation, especially the separation method of 2009 0927. The pore-thickening product of the granules can provide a suspension fluid containing all amounts of solid particles::: The phase of the liquid consisting of the solvent (or solvent mixture). However, it is achieved by using a density difference, σ, for separation, preferably by sedimentation or sedimentation, wherein the operation is performed for a period of time necessary to precipitate all particles. The operation is followed by the supernatant obtained before the recovery. Operation of the liquid: The operation of the overflow of the mixture of the suspension fluid and the solvent is carried out. , operation (a) (b), (e) can be repeated in the proposed method _ up to two: item Hi to 'according to the preferred scheme using the precipitation method, can produce a total of two items of extraction, avoidance, β, Total, bh and spill recovery operations. Depending on the solvent used to suspend the fluid from the suspension fluid to be separated from the powder contained therein, the number of repetitions of the operation of sedimentation/spill recovery according to the extraction core (4) b may be selected. However, the last (four) is that the parameter representing the number of repetitions is the capacity of the 悬浮 suspension obtained at the end of the spill (4) (10) coffee Hty), which is the consumption, powder and a small amount of suspension. Composition of the agent. In the method φ v according to the present invention, the deposition time is set to provide all of the carbonized carbide particles, the fine particles of the stone, the "wearing material," (essentially iron) fine powder, regardless of its size. The time required for the temple. The dilution ratio of the solvent to the suspension is i: 3 to i: 2〇, and the time required for the precipitation of the experiment is 1 to 24 hours. 4* ο ι After the release of the particularly favorable conditions of the force (according to the PEG or oil suspension/inner agent, and the size of the particles in the suspension 21 200950927), the liquid (4) (4) separation is carried out by means of a close grinding to the β 遽 method. The method can be executed by using the method, and the method is replaced by the method. This (4) can be performed only in one step filter, and the filter can also be used to clean and recover the suspended fluid and finally dry the filter cake. -_ . Tian Wanfa's operation using solvent extraction a), the solvent mixture for the drainage ' ' 泥 / / / 浓 浓 / / 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常 通常^

And preferably 疋 equals 1:7. After the mixed solvent / / lake operation b) has! i duration between 7 hours and preferably has a duration of approximately 4 hours. What is even more puzzling is that the solvent used to extract the suspended fluid is preferably digastric (also known as DCM), which is suitable for treating pEG-based suspension fluids and processing oil-based suspension fluids. By. When suspended, the buoyant is oil. The solvent may also be selected from tetraethylene and n-hexane. When the suspension fluid is polyethylene glycol, the other two preferred choices for the solvent are ethyl acetate and 2-propanone. As an alternative to a single solvent, it is advantageous to use a solvent mixture, in particular a mixed Q of di-methane and toluene which will be described later, or a mixture of cyclohexane and di-methane, by extraction, In the method according to the invention, in which the first and second or third step slaves of the sink and overflow recovery are carried out, the final recovery step through the spill leaves a solvent rich in solids and having a low residual residual fluid in the reactor. - a solid slurry; this slurry is mixed with a little fresh solvent and then fed to the final separation step, where all solids present are finally separated by filtration. 22 200950927 According to the present invention, from the preferred embodiment, the residual phase of the recovery operation 从) from the last stage is diluted by the solvent (or solvent mixture) to the discharged mud/moisture portion by the dilution operation of the fresh solvent. The ratio is between 2: ! and H ★, and the preferred ratio is approximately 7.·1ν/ν. After filtration, the filter cake is washed, the remaining and the last traces of suspended fluid are recovered' and the transition cake is finally dried. Preferably, the solvent (or solvent mixture) is equal to about 0.5 times the amount of discharged muddy heat and the dead pulp fed into the process.

Compound)) to carry out the cleaning operation of the filter cake f). It can be seen from the previous description that the purpose of the method proposed by the present invention is to completely separate all suspended solids in order to obtain a purified suspension fluid, and otherwise to be present as a dry powder in the initial discharge mud/thickness in the mud. All solids within are free of any residual suspending fluid. The above object can be attained by using the multi-P method of the present invention, wherein the number of stages for extracting the marriage overflow and the amount of solvent added per sediment are based on the presence of the (IV) floating fluid present in the discharged mud/concentrated mud. Characteristics and depending on the filtration capacity of the suspension obtained from the final recovery of the spill. Thus, 'a very elastic method' is produced in which the number of stages of liquid-solid extraction can vary as a function of the physicochemical properties and viscosity of the suspended fluid and the filtration capacity of the slurry. 'In addition to the discharge of mud, the method proposed by the present invention can also be applied to machining operations from the semiconductor industry by, for example, centrifugation: and individual shank portions obtained by similar operations of photo-electric energy sources: , (age mud) on it is known to contain a large amount of suspended fluid. 々 In addition, this method can also be applied to the case of machining operations that do not require the use of abrasives added on cutting green 23 200950927, but there is still oil to be recovered or (d) main cooling fluid. In this case, the solids from the mud from which the suspended liquid is recovered are composed of ruthenium particles and metal self-cutting tools. In fact, the table below shows a list of mud/rich parts. The goal is to separate the suspended fluid from the solids contained therein. Once the fresh mud is prepared, the mud plant is used to resuspend the fluid for use. Some can be handled with the proposed technique.

In order to select a solvent for separating the suspended liquid from the solid contained in the sludge, the characteristics of each solvent have been considered, and the results are shown in the following table. 〇 〇 table solvent to take the characteristics of the suspended fluid boiling point (°c) n-hexane benzene methane ether 69 80.1 40 3 flammability index 4 toxicity refers to the number - notes - 1 J for non-polar suspension fluid 4 for non-polar suspension flow艎2 for non-polar and polar suspension fluids tnj general solvent 24

Based on the above information, the criteria chosen can be determined by the following objectives: a) In order to extract the suspension fluid from the oil-based mud and the PEG-based mud using the same solvent, the solvent must have a non-polar liquid with, for example, oil and Affinity of both polar liquids of PEG; 200950927 b) a solvent having a low flammability index and a low toxicity index; c) a solvent having a low boiling point and having a latent heat of vaporization of less than or equal to other solvents is preferred. ^ For the purpose of treating oils with pEG-based muds with the same solvent and the same method/equipment, the analysis of the characteristics of different solvents has demonstrated the convenience of using two-gas smoldering (DCM) as a solvent; For the main mud, the solvent that can be used (as the sole solvent) is ethyl acetate and 2-acetone in addition to dcm. In the case of treating only oil-based mud ❹ and using only a single solvent, a solvent which can be used in addition to dioxane is tetraethylene and n-hexane. As an alternative to a single solvent, the choice of a mixture of two or more suitable doses of solvent (cosolvent technology) allows for better adjustment of the solvent characteristics used to extract the suspended fluid depending on the characteristics of the suspension fluid itself, and thus The extraction of suspended fluids is achieved with a single pure solvent. An alternative to using pure dioxane is to use, for example, a mixture of toluene and DCM, or a mixture of cyclohexane and DCM. The disadvantage of using co-solvents is the need for more sturdy storage 25 200950927 tanks, but provides better extraction process performance in terms of the required solvent volume. Starting from the analysis of the physical properties of pure solvents, as shown in the table below, the advantages obtained by using a mixture of di-methane and toluene can be demonstrated. DCM Toluene density 1.326 kg / 1 0.867 kg / 1 Evaporation heat 79 kcal / kg 86.7 kcal / kg Hilderbrand N ° (solvent capacity, 10.4 8.7 surface tension 28.1 dyne / cm 28.5 dyne / cm dipole moment 1.8 0.4 dielectric constant 9.1 2.38 Viscosity at 20 ° C 0.8 cps 0.6 cps For example, the above two solvents are mixed by a volume ratio of 丨:3·7. According to the following table, the obtained mixture has different physical properties with respect to pure DCM: - evaporation Heat: increased to 84.45kcal/kg - surface tension: similar to 曱 - - dipole moment: reduced to 〇.6_〇·5 (modified); this mixture is less polar than pure DCM 'but more polar than hexane - Dielectric constant: lower than DCM _ expected viscosity of the mixture: 0.7 cps These two solvents are miscible, so they are used as a mixture. 26 200950927 Requires 5 to 6 feeding trays (trays in enrichment) and 3 to 4 distillation columns in the exhausts in exhaustion to replace simple evaporation. In terms of flammability of the mixture, due to the odor in the diazepine Going out of the steam, thus causing pure Reduction of flammability of benzene. In general, the use of a solvent mixture instead of a pure solvent optimizes the extraction-precipitation process and filtration as a function of the characteristics of the discharged mud to be treated. A. Countercurrent Extraction of Suspended Fluid As shown in the block diagram of Figure 1, the method of the present invention is a countercurrent flow by extracting-precipitating-recovering spills from n stages (n ranging from 1 to 3) In this case, the present example refers to a total of three stages. The first stage of the extraction of I, the reactor R01 discharge mud is mixed in the reactor R01 with the mixture recovered from the reactor R02, the volume is diluted The ratio (volume of discharged mud: volume of solvent) ranges from 1: 2 to 1:1, depending on the type of suspension fluid that exhibits the characteristics of the discharged mud and the type of solvent used. In the description, consider using a preferred solution with a dilution ratio of 1: 7. 27 200950927 Far_House I, and should be, R01 diluted into a 1: 7 suspension, sipping it for a period of time, making it hanging All the solid particles in the float can reach the final equilibrium speed of the squid and reach the mixture of the solvent and the suspended liquid. The area below the height of the level where the incision can be affected can be affected. Plug J ^ as a function of the suspended fluid (whether oil or PEG) and the solvent used (for example, a U.S. solution such as .DCM, hexane or a mixture of cosolvents), this precipitation time may be white, ,, _ ^ 叮Ν ! Contains between 1 and 7 hours, the pass is about 4 hours. Overflow_Export Recovery I, Reaction ^ This operation consists of aspirating the supernatant of the diluted suspension settled in the reactor RG1; this supernatant is fed to a collection tank (suspended liquid + solvent) D1 'and then To a separation system that separates the solvent from the suspended liquid by a steaming method, the yield of this operation is not less than 99%. The suspending agent is present in liquid form in the first spill recovery in an amount of from about 6 to about 7%. The volume of the clear phase that is drawn is seven times the volume of the discharged mud fed to the reactor R〇1. Stage 2 extraction II, reactor RO) The remainder of the mud from the spill recovery I (the volume equals the volume of the discharge mud charged into the reactor for extraction I) is sent to the reactor 'and with overflow The solvent-suspension of the recovered hydrazine (reactor R 〇 3) is now mixed with the 2009 2009 927 mixture, and again the volume dilution ratio is approximately equal to 丨:7. Precipitate II, reactor R02 is diluted to 1:7 (four) float to allow it to scale for a period of time, this (10) time can be between 1 and 7 hours, usually about 4 hours. Spill Recovery II, Reactor R02 This operation consists of a supernatant of the diluted suspension settled in the suction reactor R02. This supernatant is fed to the collection tank D2 and then to the reactor R01. precipitation. The suspending agent is present in liquid form in the first spill recovery in an amount of from about 2 to about 3%. The volume of the clear phase that is drawn is seven times the volume of the mud fed to the reactor. The third stage

Take III, the reactor pq comes from the overflow recovery ΤΤ ΑΑϋΛ the remaining part of the mud of the 1 (the volume is equal to the row in the reactor for extracting I, clothing

The volume of the effluent sludge is sent to the reactor R and mixed with the dissolved refrigerant-suspension mixture from the filtration operation, and A - its volume dilution ratio is approximately equal to 7. The solid system thus resuspended for a long time is left to settle for a period of time, so that the solid particles in the sweat of the suspension 2009 2009927 can reach the final equilibrium speed and reach the area below the level affected by the spill recovery III. This precipitation time can range from 1 to 7 hours, usually about 4 hours. Overflow_.Dropage recovery 111_, reverse reactor This operation consists of the supernatant from the diluted suspension settled in the reactor R03. This supernatant is fed to a collection tank D2 and then to the reactor R02. In the middle of the temple. In the first spill recovery, the suspending agent content ❹ in liquid form is approximately 0.5%. The volume of the clear phase that is drawn is seven times the volume of the discharged mud fed to the reactor R〇1. B) The filtration method is a suspension of the solid powder dispersed in the solvent in the reactor R03, and the residual percentage of the suspension liquid is less than 〇5 to 1%, and the suspension is sent to the tank D04 and is about the volume The seven times pure solvent is mixed and then sent to the filtration operation. The filtration operation is quite fast due to the low viscosity of the suspension after the initial dilution of the suspension liquid. The filter cake was washed with a small amount of pure solvent (about 〇 5 V), which resulted in a residual content of the suspension agent of about several tens ppm relative to the solid. Finally, the solvent used to clean the filter cake is added to the liquid produced by the extraction itself and is sent to the reactor R 3 for extraction. The final yield of the suspended liquid present in the effluent suspension should be above 99% from 30 200950927. The solid portion t/cake is composed of all the solid components present in the initial discharge of the mud/thick sludge, and is wet due to the residual solvent for cleaning. For this reason, therefore, the filter cake is sent to a drying operation, whereby a dry powder constituting the solid composition can be obtained while the solvent vapor is sent to the condensation and recovery.液体 Liquid portion ^ The liquid portion consists essentially of solvent with a residual content of lev. 5%. By filtration, this portion is sent to tank D5 and then sent to reactor R03 for sedimentation. The present invention has been described with reference to a particular embodiment of the present invention, but it is understood that many modifications can be made to those skilled in the art without departing from the scope defined by the scope of the present invention. With changes. BRIEF DESCRIPTION OF THE DRAWINGS The features, advantages, and related operational forms of the present invention will become more apparent from the detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an overall block diagram showing a method for separating and recovering suspended liquid contained in a discharged slurry in accordance with a preferred embodiment of the present invention. 31 200950927 [Explanation of main component symbols

Claims (1)

200950927 X. Applying for a patent, Fan Gu·· 1.- A method for separating and recovering suspended liquid contained in the mud or in the part, the discharge is slightly abrasive and from the Gu Gu - ' whether or not the pottery material Machining, two: eve material, quartz, other work, the child method comprises the following steps: diluting Hi! suspension fluid mixed solvent or solvent mixture for dilution, and extracting the suspension fluid from the discharge mud / thick portion; b) treating the pre-released suspension by liquid-solid separation; diluting C) the supernatant obtained by the previous operation (s(four) aunt), which consists of suspended fluid and solvent or Composition of a mixture of solvent mixtures; the aforementioned series of operations in the first stage a). ) can be selectively repeated in one or two additional stages; by separating the solvent or solvent mixture from the first stage of operation c): the obtained liquid is separated by 'recycling Suspension fluid; from each Additional stage of operation # e) The obtained supernatant is fed to the extraction operation of the previous stage a); e) The residual phase of the recovery operation c) from the last stage is diluted with a solvent or solvent mixture, and the transition The resulting diluted suspension thereby produces a filter cake containing substantially all of the solids present in the mud/concentrate portion. 2. The method of claim 1, wherein after the filtering of operation e), the following operations can be carried out: f) cleaning the cake, thereby recovering a solvent having a trace amount of the suspension fluid or a mixture of the mixture; g) The filter cake produced by the previous operation of drying. 3. The method of claim 3, wherein the liquid phase obtained from the filtering of the operation is fed to the final stage of the extraction operation ^. 4. The method of claim 2, wherein the operation e) The liquid phase obtained by the filtration is fed to the final stage of the extraction operation. 5. The method of any one of claims 1-4, wherein the liquid-solid separation operation is by density difference, © For example: The method of the fifth item of the patent scope, wherein: the operation of the knife by the difference in density b) is centrifugation. 'The obtained by the density difference one operation' is obtained by the density difference--operation 7' The method of claim 5, wherein the separate operation b) is precipitation, and the operation of the supernatant before the recovery c) is the recovery of the overflow. 8. If the scope of claim 2 is The method wherein the separately separated operation b) is a precipitation, and the operation of the supernatant before the recovery c) is the recovery of the overflow. 9. The application of the liquid-solid separation operation b) is filtered. Any one of the items ,among them, The method of the present invention, wherein the mud/thick portion is 10. As in the scope of claims 1 to 4, in the operation a), the dilution ratio of the solvent or solvent mixture to the discharge is between 2:1 and 1. 〇: 1 v/v between. Π If the scope of the patent application is about 7: lv/v. The method of any one of claims 1 to 4, wherein 34 200950927 the solvent is dichloromethane. 13. The method of any one of claims 1 to 1, wherein the suspension is oil and the solvent is selected from the group consisting of - and hexane.疋 自 - 曱 、 、 、 、 、 、 、 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如Methane, acetic acid, and 2 ❹ · 15 · The method of any one of the above claims is a mixture of dimethylhydrazine and toluene or a mixture of cyclohexane and dichloromethane. . "疋 16. As in the m h^w ^ ^ method of claim 7, the step b) of the precipitation has a duration between i hours and 7 hours. 17. The method of applying for the patent scope of item 16 沬 + + + 趣 曰 ’ ’ , , , , , , , 。 。 。 。 。 。 。 。 。 。 沉 沉 沉 沉 。 。 。 。 。 。 。 。 。 18. The method of claim 1-4, wherein the residual phase obtained by the final stage recovery operation is diluted with a solvent or a solvent mixture, e), (4) solvent or dissolved-(four) The dilution ratio of the mud/thick portion is between 2:1 and 1〇: and iv/v. 19. The method of claim 16, wherein the residual phase obtained by the final stage recovery operation #e) is diluted with a solvent or a solvent mixture e) 'using a solvent or solvent mixture pair #出泥^ The dilution ratio of the thick portion is between 2.1 and 1 〇: 1 v/v and is carried out according to the method of claim 19, wherein the dilution ratio is about 7 _ 1 v / v. The method of any one of claims 2 to 4, wherein the operation of washing the filter cake f) is to use a solvent or solvent mixture equal to 0.5 times the volume of the discharged mud fed to the method. And implementation. 22. The method of claim 16, wherein the operation of washing the filter cake f) is carried out using a solvent or solvent mixture equal to 0.5 times the volume of the discharged mud fed to the method. XI. Schema: as the next page 36