TW538112B - Method for treating an exhausted glycol-based slurry - Google Patents

Abstract

A method of separating, recovering and reusing components of an exhausted slurry used in slicing silicon wafers from a silicon ingot. In the method, the solid particles and lubricating fluid of the exhausted slurry are separated without decreasing the viscosity of the exhausted slurry. The separated lubricating fluid may be collected and reused in the preparation of a fresh slurry. Additionally, the silicon particulate and metal slicing wire particulate are dissolved and separated from the abrasive grains. The abrasive grains are separated into spent abrasive grains and unspent abrasive grains. The separated unspent abrasive grains are suitable for reuse in the preparation of a fresh slurry.

Description

538112 V. Description of the invention (l) Background of the invention The present invention is a comprehensive method for regenerating a polishing slurry used to prepare silicon wafers. The present invention is more particularly related to a method for separating depleted slurry components for slicing stone wafers from single or polycrystalline silicon ingots, so that the required grinding particles, grains, and lubrication or cooling fluids can be reused. To obtain a silicon wafer from a single or polycrystalline silicon ingot, the silicon ingot is first sliced in a direction perpendicular to its axis. The slicing operation is generally performed by a metal wire saw, in which the stone ingot is brought into contact with the reciprocating metal wire, while a slurry containing abrasive particles is supplied to the contact surface between the spiral wire and the metal wire. Conventional wire saw slurries generally include slip or cooling fluids [such as mineral oil or some water-soluble liquids (such as polyethylene glycol or "PEG"]) and abrasive particles (such as carbonized stone). During the slicing operation, formed from ingots Silicon particles and metal particles (basically iron) formed from the slicing line and metal tube enter the slurry. Due to the increase in the concentration of stone particles and metal particles in the slurry, the efficiency of the slicing operation is reduced. Eventually, the slurry becomes invalid or " "Depleted", must be discarded. Usually, the slurry is consumed by incineration, or treated with waste water treatment equipment. However, burning the slurry to produce dioxide will instead send this aggregate to the waste water treatment equipment. Therefore, from the environmental point of view, the two methods are safe. Households are best to eliminate or meaningfully reduce the amount of waste generated. 2 5 In addition to the negative environmental consequences and costs associated with depleting the polymer, In other words, the slurry internal research also increases the manufacturing cost of Shixi wafers. To be more precise, it cannot be effectively cut ^ f ^ particles are consumed by the slicing operation ", (that is, worn to the size of the pan contaminated by small particles) The polymerization rate is generally better than expected by the stone and metal microstructures Xi, ... smaller. In addition, the lubricating or cooling fluid of the general

Page 5 538112 V. Description of the invention (2) The service life is almost completely affected by the concentration of silicon and metal particles in the silicon and / or metal particles is not increased, that is, if the pulp is used for a long time. Therefore, usually-the cooling solution may be too high in particle content, the slurry should be discarded, and f and / or metal micro-sliding fluid in J can still be used. 1 There are more abrasive particles and lubricants. In view of the foregoing, there is a need for a method that can be linear particles, and thus can be reused; the self-slurry, ionization, and gold methods will reduce the production and lubrication fluids associated with silicon ingot slicing. The cost of such waste products and / or waste by-products discharged into the environment. In addition, the method is reduced in the summary of the invention. We can pay attention to the method of the slurry component life of several targets and slices of the present invention. Thumbs are used to extend the regeneration of these components for silicon ingot separation. The self-consumptive lubricating fluid is separated from the solid to effectively regenerate the lubrication f = 22 = to separate the particles in the f material and regenerate the unconsumed grinding 2 ::: grains, silicon particles and metal lubrication fluids and the regenerated grinding particles. Provide the method of separating and regenerating the generated materials: = ::;: ;; method for the production of wafers; extracting and reusing the separated and consumed abrasive particles = (such as the method of ^; provide it or cement); provide JL in _ ^ Methods (for example, methods for manufacturing the amount of waste from the grinding wheel; and methods for reducing or eliminating the need to discard them. And methods to reduce the cost of manufacturing silicon wafers 538112 V. Description of the invention (3) Shi Xi wafer exhaustion Slurry _. ^ Consumption of abrasive particles, reddish j = = f exhaust slurry includes lubricating fluid, unfinished slurry is separated into first and second particles of silicon and metal particles. Consumption fraction includes single slip fluid, Body: two f-th solid fractions, th-liquid after grinding particles, Granules ::: Including unconsumed abrasive particles, particles and metal particles, and liquid separation into the first-liquid fraction of Runqiao II = the first solid fraction includes unabrasive particles, consumable abrasive particles, silicon particles and Metal particles. The first solid fraction is mixed with water to produce an aqueous liquid solution containing non-fluoridated particles, depleted abrasive particles, silicon particles, and metal particles. The aqueous suspension is separated into a recycle fraction and a waste fraction 'The bad fraction includes unconsumed abrasive particles, silicon particles, metal particles, and water, and the waste fraction includes depleted abrasive particles, silicon particles, metal particles, and first rot #:: A First solid / rot # 刎 \ mix. The first solid / corrosive mixture is separated into a second liquid and a second solid fraction, and the second liquid fraction includes the first etchant and the dissolved silicon particles or Dissolved metal particles, the second solid fraction contains unconsumed abrasive particles and silicon particles or metal particles that are insoluble in the first etchant. The second solid level is mixed with the second etchant to generate dissolved silicon particles. Or a second solid / corrosive mixture of metal particles. The second solid / corrosive mixture is separated into a third liquid fraction and a third solid fraction, the third particle and the Hit and f-ring fractions are separated, and then the recycle stage is Divide / corrosive mixture 'to produce f WAk II, X β ...

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Page 7 538112 V. Liquid particle mill-grade solid and low-lubricant washing silicon combined with decontaminated solid acid particles dry concentrated body Description of the invention (4) Body grade ^ Including second etchant and dissolved silicon particles or dissolved metal particles The ^^ solid fraction includes unconsumed research suitable for direct incorporation into fresh pulp. In the examples, the depleted polymer system is separated into the first-liquid: L; ΐ ΐ, the first liquid stage It includes lubricating fluid, No.-Man® knife and knife, Xiao consumption abrasive particles, consumed abrasive particles, Shi Xiwei extremely first ## 八八 + ”body. The solid level is cleaning with solvent to reduce the production of fluid The concentration of the lubricating fluid is t2, and a solvent-containing and wet liquid grade II is added. The cleaning liquid is added to the first liquid fraction, and the temperature is about 5 ° c to about 10 ° C (the temperature in the range of rc to evaporate the solvent).一 固 i The di-carcass fraction is suitable for direct blending into fresh slurries. After the particles are mixed with the if / hydroxide Λ! Solution, the dissolved matter is separated and propagated. ^ Etchant mixture ° will be the first solid / Etchant mixed water hydrogen child service two liquid fractions and a second solid fraction, the second liquid subcontracting research; The second solid fraction includes undivided fishes! Consumption of abrasive particles and metal particles. The second solid body / corrosive acid solution is mixed to generate the second and third particles in which the metal particles are dissolved. Liquid corrosion agent ^ mixture. This second solid / corrosive agent mixture is separated into a liquid i and a third solid fraction, the third liquid fraction includes aqueous sulfur particles and f metalloid particles, and the third solid fraction includes Grinding is not consumed, and the abrasive particles are consumed. The third solid fraction is washed with water, and then the water content is less than about 100 ppm. If the consumed abrasive particles are equal to the weight of the third solid fraction, Less than about 7%, after drying, the third solid, '77 is suitable to be directly incorporated into the fresh slurry. 538112 V. Description of the invention (5) In a more solid fraction and the first solid fraction, the metal and the metal are reduced to reduce The first and first solvent cleaning and dissolving silica mixed fractions include the second particle, including water consumption, suspension and recirculation, and the fluid and liquid level are smoothed until the composition of the first solid particles Including water-containing second solid Into the first sulfuric acid grinding particles to produce a liquid. In the specific embodiment of the ring fraction, the ground particles are not separated into the water-containing embodiment. The depleted slurry is separated into a first liquid solid fraction, and the first liquid fraction includes a lubricating fluid. The first includes unconsumed abrasive particles, depleted abrasive particles, silicon particles, and moisturizing bodies. The first solid fraction is washed with a solvent, the concentration of the lubricating fluid in the solid fraction, and a cleaning solution containing the solvent is generated. The cleaning liquid is added to the first liquid fraction, and the fraction is heated to about 50 t to about 〇. (: Range temperature, in order to evaporate the second liquid fraction is suitable to be directly incorporated into the fresh slurry. The warp body fraction and water The argon sodium oxide solution was mixed to produce a first solid / etching agent mixture therein. The first solid / corrosion is separated into a second liquid fraction and a second solid fraction, a second liquid sodium hydroxide solution, and dissolved silicon particles; the second solid level is abrasive particles, depleted abrasive particles, and metal particles. . The mixture is mixed with an aqueous sulfuric acid solution to produce a dissolved metal micro / humid agent mixture. The second solid / corrosive agent is mixed into a three-liquid fraction and a third solid fraction, the third liquid fraction includes a solution and dissolved metal particles, and the third solid fraction includes ungranulated and consumed abrasive particles. A third solid fraction is mixed with water. The aqueous suspension containing unconsumed abrasive particles and depleted abrasive particles is separated into a recycle fraction and a waste fraction, including unconsumed abrasive particles and water. And water. Separating the recycled fraction into reusable suspended liquid consumes abrasive particles. The separated unconsumed abrasive particles are dried in an amount less than about 1 0 0 0 p p m.

538112 V. Description of the invention (6) The granules are suitable for direct incorporation into fresh slurry. Other objects and features of the present invention are partly obvious and partly mentioned later. Brief description of the diagram '' FIG. 1 is a flowchart illustrating some steps for separating the components required for the depleted slurry according to the present invention, and some are selected as appropriate. Specifically, Figure 1 ‘guides the separation and recovery of lubricating fluids. Figure 2 is a flow chart illustrating some of the steps required to separate the components of a depleted slurry according to the present invention. There are some options. Specifically, Figure 2 guides the separation of silicon and metal particles. Figure 3 is a flow chart illustrating some steps for separating the components needed for the depleted slurry according to the present invention, some of which are selected as appropriate. Specifically, Figure 3 guides the separation and recovery of carbide particles. Detailed description of the invention In order to reduce the amount of waste generated by standard silicon wafer processes and reduce the costs associated with the usual manufacturing of silicon wafers, it is ideal to regenerate or recycle the depleted abrasive slurry used to slice the silicon ingots into wafers. More specifically, it is desirable to separate the slurry components (i.e., lubricating fluid and unconsumed grinding particles) that are still suitable for ingot chipping from the remaining slurry, and prepare the fresh slurry with the desired separated components. Depleted abrasive slurry components (ie, consumable abrasive particles, silicon particles, and metal particles) that are no longer used to prepare fresh slurry can be used in other applications. In this context, π depleted slurry refers to a slurry that is no longer suitable for slicing silicon wafer applications due to unacceptably high levels of silicon 11 and / or metal particles preventing the slicing operation. It is currently believed that silicon particles are

Page 10 538112 V. Description of the invention (7) The solid substance concentration by weight is higher than about 1 to 5% by weight), which hinders the slicing operation of Shi Xijian. It is also believed that, when # / 微 " is about 0.5 to 2 weight «(preferably higher than about (weight H ^ agricultural. |, Consumption of abrasive particles) means that the abrasive particles are worn due to the slicing process. Or the size of the abrasive particles is no longer suitable for slicing silicon wafers from silicon ingots. It is currently believed that the abrasive particles are consumed to less than about} micron size / unconsumed abrasive particles "means that the depleted slurry is still suitable for self-use. Grinding particles for ingot slicing of silicon wafers (believe that their size is greater than about 1 micron). At present, it is possible to compare the consumption of the abrasive particles at their concentration to the total abrasive particles (ie, the "consumed and unconsumed abrasive particles) = Approximately 5-10 weight ^ Obstructs the operation of silicon ingot slicing. "Viscosity" means the redness of the slurry is the same as the above, and the common method for detecting or measuring the flowing slurry is the same as the method of the present invention. Separate the waste solids (ie, silicon micro-man-abrasive particles) from the reusable slurry components (ie, ,,, and particles and de-abrasive particles), by (1) making the suspension fluid slip And unconsumed (2) make the abrasive particles (consumed and unconsumed) and Separate from the lubricating fluid, (3) Separate the consumed and unconsumed abrasive particles, phen and metal particles, and t-segment baskets and moisturizers. General reference is made to the self-lubricating fluid separation according to Figure 1 of the present invention. Available Any method to make solid matter in the slurry (for example, about 5 micrometers, 3 micrometers, i micrometers or: 卞 diameter solid method: the lubricating stream i without solids is better. Solids, the method (for example, less than about 0.3 g / l or even more). = At about 0.5 g / l, the filtration of depleted slurry (better pressure filtration) 538112 V. Description of the invention (8 ) Is a type of pore filter device which normally consists of solids for fractions and solids (Bergamo, which can press 1 75 pounds per square pore size per hour at about 1 1 5/1 5 dead pa). Sieves are usually granulated and concentrated after the consumption of lubricating fluid, and are preferably smaller than the solid fraction in the abrasive particle separation and filtration device produced by the separation. The concentration is generally about 1%. Compared with solvents and lubricants, the solid matter is separated from the lubricating fluid. Example method. Press filter-depleted slurry passes at least Each sieve divides the depleted slurry into a liquid fraction, such as a polypropylene sieve having a size sufficient to substantially remove the diameter or mesh size from the fluid at high pressure. An exemplary Diefenbach [Italy, Berger Italy)] model de800 / 59pp. About 300 liters to about 700 liters are exhausted for pressing (preferably about 5000 liters / hour) square inches (about 0.8 MPa) ) To about 220 psi (approximately about 145 pounds per square inch (about 1.0 MPa) to about inches (about 1.2 MPa)) through less than about 5 microns Or sieve (preferably less than about 3 microns, more preferably less than about 1 micron). Filtration produces a solid fraction π cake, "which includes silicon particles, metal microabrasive particles, unconsumed abrasive particles, and a lubricating fluid (moderate cake is generally less than about 25% by weight of the cake, preferably less than about 20% and about 15% (Less than about 10% or even better). Further processing from the solid fraction to silicon particles, metal particles and abrasive particles that have not been consumed after consumption. However, it is preferred to use the same solvent (such as 'water or formamidine') for separating solids. 'Preferably water) washing to reduce the concentration of the lubricating fluid. After washing, the cake is less than about 5% by weight of the cake, preferably less than ^ before the liquid fraction is further processed, the solid fraction / month, " U The body (" cleaning solution ") is added to the previously separated liquid fraction and can be directly re-circulated. The liquid fraction generated from the separation is substantially free of solids.

538112 V. Description of the invention (9) The ring enters the silicon wafer process and is used as a lubricating or cooling fluid for Shi Xixuan's slicing aggregates without additional separation or processing steps. Generally up to about 0.5 g / l of residual solid particles remain in the liquefied fraction. Residual solid particles are generally predominantly silicon with a diameter of less than about 0.3 microns. However, if necessary, you may choose to clarify the π step with π, where the fraction is subjected to an additional separation step to reduce the concentration of residual solid particles. Any method for separating solids of about 0.1 micron or less may be used, and the above-mentioned filter press method is preferably used. After clarification, the solids content of the liquid fraction is generally reduced to less than about 1 weight P P b. As mentioned above, the method of the present invention allows the liquid fraction to be recycled after separation or clarification. However, if a cleaning solution is added to the liquid fraction, it is preferred to separate at least a portion of the solvent from the liquid fraction by evaporation or distillation. The solvent is preferably evaporated by heating the fraction. In the case where the liquid fraction contains a π glycol π based lubricating fluid, it is preferably heated to a temperature of about 50 ° C to about 100 ° C, and more preferably about 80 ° C. To promote evaporation, the pressure experienced by the fraction can be reduced, but atmospheric pressure is preferably used to minimize process complexity and cost. Evaporation increases the concentration of the lubricating fluid in this fraction and continues until the lubricating fluid reaches a viscosity suitable for preparing fresh slurries. For example, prior to concentration, a fraction containing " ethylene glycol " -based lubricating fluid and water typically has a viscosity of about 1 centipoise (cps) to about 2 centipoise at about 70 ° C to about 90 ° C. Continue to evaporate until the viscosity of the fraction is about 10 centipoise to about 15 centipoise at about 70 ° C to about 90 ° C. After cooling to about 25 ° C, the lubricating fluid is separated (ie, Viscosity fraction) preferably has a viscosity of about 90 centipoise to about 120 centipoise, and can be used to prepare fresh slurry. Lu B. Separate the grinding particles and silicon and metal particles, the solid separated from the depleted slurry The fractions are further processed so that the consumed and

Page 13 538112 V. Description of the invention (ίο) Unconsumed abrasive particles are separated from silicon particles and metal particles. To facilitate the separation of the abrasive particles, 'the solid fraction (cake) from the initial separation is mixed with at least one corrosive agent' to dissolve the particles and metal particles. For example, the solid fraction may be mixed with an etchant capable of dissolving both silicon particles and metal particles. One such corrosive includes hydrofluoric acid (HF) and nitric acid (HNO3), which are generally relatively high concentrations (eg, 'HF and HNO3', generally accounting for about 10 to about 20% by weight of the solution, respectively) 15% by weight). However, high-concentration Ding-HNO3 corrosives are susceptible to danger and require adequate safety precautions. Therefore, it is preferable to use a corrosive agent with little danger. Generally, a corrosive agent that dissolves silicon particles and a heterogeneous humus agent that dissolves metal particles is required. The order in which silicon and metal particles dissolve is not important, but the following discussion and the flow chart of Figure 2 provide for dissolving the stone particles before dissolving the metal particles. 1 ..., _ Separation Silica_ 厶 Generally referring to Figure 2, the solid fraction from the initial separation is mixed with the etchant to generate a solid / corrosive mixture in which the silicon particles are dissolved. The etchant is preferably an aqueous solution containing an alkali metal hydroxide (e.g., NaO} I and KOH) and / or an alkaline earth hydroxide [e.g., Ca (0H) 2]. The etchant is more preferably from about 6% to about 20% by weight (more preferably from about 8% to about 15% by weight 0/0) and ^ an aqueous solution of hydrogen ~ oxidation pin. Generally at least about 6 liters of sodium hydroxide solution is added per kilogram of solid fraction, preferably at least about 7 liters, and more preferably about 8 liters. The amount of caustic agent added to the solid matter is optimally sufficient to dissolve substantially all of the silicon microparticles. 0 Dissolution of silicon by the experimental residues results in the generation of soluble alkaline / alkaline earth metal salts (e.g., N ^ SiO3) and hydrogen. Hydrogen can be collected and used for other applications.

Page 14 538112 V. Description of the invention (II) 1. Self-corrosion unit 丨 Separation and solidification After the silicon particles are dissolved, the remaining solid materials are separated from the corrosive agent containing soluble particles of calcite. It is preferable to dissolve the solid / corrosive agent through a pressure filter previously used to separate the solid fraction from the self-lubricating body, and σ through investment in equipment related to the regeneration method. So: the reduction of abrasive particles, unconsumed abrasive particles, gold eyebrows, and consumption. If needed ’, you can dilute the cake with water and excess: etchant. The amount of middle rot surname agent. After dilution and mashing, 1ί: minus: cake to about 0.1% by weight. Ding Man doing A / Chen degree is generally small k to separate the metal Zen grain He Shixi = Li. ΪSolid grade ... ^ Consumable abrasive particles from now = Solid fraction 'separate unconsumed abrasive particles and consumed abrasive particles from metal particles. The corrosive 74 acid solution, aqueous nitric acid solution, and mixtures thereof are more suitable for the '2 sulfur sulfur J sulfuric acid solution. Corrosion shot: The self-corrosive agent is wt%, more preferably from about G.4 wt% to shaved weight and better from wt%. The solid fraction is added by dissolving at least about 6 liters of sulfuric acid. Φ Young s ^ ^ Ping Jiajia is at least about 7 liters, and the best amount of solution is only enough to dissolve all metal particles on the fresh storm. Soluble salt compounds such as ferric sulfate (e.g. p2 (b04) 3 and FeS04), copper sulfate, and zinc sulfate are formed with the acid = digested metal, and these steps are separated from the solid fraction by the method described above The beta remaining solids fraction includes unconsumed & abrasive particles and depleted abrasive particles. Residual acidic corrosive agent can be used to dilute the cake with water 538112 V. Description of the invention (12) Eliminate the unused abrasive particles to eliminate waste. The I il slice slurry is generally depleted by metal or silicon particles more than by consumption: '... doesn't have to be like separating metal and stone particles: ΐ i Consumed and unconsumed abrasive particles. Normally, when the consumed abrasive particles have a spread greater than about 5-10% by weight based on the weight of the entire abrasive particles (car is better about 7 weight percent) 'Separate the consumed and unconsumed abrasive particles, which should be the abrasive particles The particle size distribution changes by about 1 to 2 microns. f In the method of the present invention, the consumable and unconsumed abrasive particles can be separated at any point in separating the solid fraction (including the consumable and unconsumed abrasive particles and silicon and metal particles) and the liquid fraction (including the lubricating fluid). For example, the separated consumable and unconsumed abrasive particles can be dissolved before dissolving the silicon particles and the metal particles 1 after dissolving the silicon particles or the metal particles or after dissolving both the silicon particles and the metal particles. Separation of unconsumed abrasive particles by the sum of dissolved silicon particles and metal particles is preferred. OK, ·, self-consumption can be separated by any device commonly used in technology that can separate particles according to weight or size, such as a hydro-cyclone separator, a sedimentation centrifuge, a filtration centrifuge, or a filter (together with Necessary selection of filter cloth with suitable pore size). Separation by a hydrocyclone is preferred because $ has a relatively low cost and durability (for example, German A κ W company r w K 8 1 0 ′, type). With full reference to Figure 3, the remaining solid fraction (ie, the consumed and unconsumed abrasive particles) is mixed with a liquid (such as water, an acid etchant or an alkali etchant) to produce an aqueous suspension (thus' which can dissolve the parameters and / or metal particles Combined with the separation of unconsumed abrasive particles). Water and solid fractions are preferably mixed in

Page 16 538112 V. Description of the invention (13) ', the solid particle concentration is about 5 g / l to 100 g / l, preferably about 15 g / l to about 60 g / l, more preferably about 25 g / l to About 30 grams / liter. In summary, in a hydrocyclone, water and solid particles having a specific gravity smaller than a predetermined amount are discharged from an upper outlet, while liquids and particles equal to or heavier than a predetermined weight are discharged from a lower outlet. In the present invention, the predetermined weight should be a particle size that allows the unconsumed abrasive particles to be separated from the consumable particles. Therefore, after the hydrocyclone separation, two suspensions are left-a recycling grade containing unconsumed abrasive particles and water, and a waste fraction containing consumable abrasive particles and water. If the knife is divided into abrasive particles, partly crushed and gold, there is an amount of unconsumed grinding agent, and the dry powder is separated from the silicon, except for the reduction of the fine grinding particles. In addition to the consumption of abrasive particles, the waste fraction also includes phases. This will significantly reduce the rot and less raw material costs required to separate the silicon and / or metal particles retained in the recycled fraction (with " particles). The erosion abrasive particles are recirculated in the wafer process after circulating the fraction filter or the pressure filter abrasive particles, and the liquid (for example, see the method to make the box. It is better to notice that the fraction detachable when the abrasive particles are inclined. In addition to water, it can be produced without drying. The liquid is removed to separate the unconsumed abrasive particles. The unconsumed abrasive particles are filtered or centrifuged by common methods. It is better to use a buffer (be used to measure the amount of liquid. It is separated from the first suspension and is not consumed. It is used for the current day and month. However, it is better to shield and dry the abrasive particles, such as regularly filtering the filter. The collected particles are relatively large solidified material because of Taikoo. When the abrasive particles are not consumed by heating and drying the silicon powder, it is better to use Φ.

Page 17 538112 V. Description of the invention (14) Temperature at which solids can be dried quickly and effectively. Therefore, the abrasive particles are preferably dried at a temperature between about 75 ° C and about 200 ° C, more preferably between about 100 ° C and about 150 ° C. Although the drying time may vary, for example, depending on the liquid to be removed and the drying method, it is generally dried to a trace or little liquid. For example, if a solid / liquid mixture is formed with water, it is determined by ordinary technical methods (such as Karl Fischer's method), and the ground solid is generally dried to a water content of less than about 5000 ppm (parts per million). It is preferably less than about 100 ppm, and most preferably less than about 500 ppm. A low water content is desirable because the presence of water causes a reduction in the viscosity of the slurry in which the recovered grinding particles are used. In addition, the presence of water in the slurry may cause abrasive particles (such as silicon carbide) to stick together, resulting in larger abrasive particles that are harmful to the wafer surface during the slicing process. The waste fraction (ie, a suspension containing depleted abrasive particles) can be discarded. However, it is preferred to concentrate the waste fraction, collect a liquid such as water, and reuse it in the method of the present invention to reduce the amount of waste generated. If necessary, collect and dry suspended abrasive particles. In view of the above, it can be seen that several objects of the present invention have been achieved, and other beneficial results have been achieved. We hope that all the situations contained in the above description are interpreted as illustrative and not restrictive.

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Claims (1)

538112 _Case No. 90113718 _ Modified _ ^ VI. Patent application temperature Temperature to evaporate the solvent from the cleaning liquid / liquid fraction mixture. 8. The method according to item 1 of the scope of patent application, wherein the first etchant dissolves silicon particles and metal particles, the method further comprising: (c) separating the first solid / corrosive mixture into a second liquid fraction and Two solid fractions, the second liquid fraction comprising a first etchant and dissolved 'silicon particles or dissolved metal particles, the second solid fraction comprising unconsumed abrasive particles and consumable abrasive particles; (d) Mixing the second solid fraction with water to produce an aqueous suspension containing unconsumed abrasive particles and depleted abrasive particles; (e) separating the aqueous suspension into a recycle fraction and a waste fraction, the recycle fraction Including unconsumed abrasive particles and water, the waste fraction includes depleted abrasive particles and water; and (f) separating the recycled fraction into a liquid fraction containing water and the separated unconsumed abrasive particles. 9. The method according to item 8 of the scope of patent application, wherein the aqueous suspension is separated into a recycle fraction and a waste fraction by a hydrocyclone (c y c 1 ο n e) separator. 10. The method according to item 8 of the scope of patent application, further comprising drying the separated unconsumed abrasive particles until the residual water content is less than 100 ppm. 001. The method according to item 8 of the scope of patent application, wherein The first etchant includes a mixture of hydrofluoric acid and acid. 12. The method according to item 11 of the scope of the patent application, wherein the concentration of the first corrosive agent < · in the concentration of hydrofluoric acid and the concentration of nitric acid are from 10% by weight to 20% by weight. 13 3. The method according to item 11 of the scope of patent application, wherein the first etchant O: \ 71 \ 71287-911122.ptc Page 21 538112 _Case No. 90113Ή8_ Year Month Amendment_ VI. Scope of patent application Both the concentration of hydrofluoric acid and the concentration of nitric acid are 15% by weight. 14. The method according to item 12 of the scope of patent application, wherein at least 6 liters of the first etchant are mixed per kilogram of the first solid fraction. 15. The method according to item 1 of the scope of patent application, wherein the first etchant dissolves-γ to dissolve the silicon particles or metal particles in the first solid / corrosive mixture, and the method further includes: ~-(c) dissolving the first solid / Etchant mixture is separated into a second liquid fraction and a second solid fraction, the second liquid fraction includes the first etchant and dissolved silicon particles or dissolved metal particles, and the second solid fraction includes undissolved Depleted abrasive particles, depleted abrasive particles, and silicon or metal particles; ⑩ (d) mixing a second solid fraction with a second etchant to form a second solid / etchant mixture in which the first solid / etchant mixture is dissolved and dissolved Silicon particles or metal particles; and (e) separating the second solid / corrosive mixture into a third liquid fraction and a third solid fraction, the third liquid fraction including the second etchant and the dissolved silicon particles or the dissolved metal Microparticles, the third solid fraction including unconsumed abrasive particles and depleted abrasive particles; (f) mixing the third solid fraction with water to produce unconsumed abrasive particles Aqueous suspension of granules and depleted abrasive particles; (g) Separation of the aqueous suspension into recirculated fractions and waste fractions. Recycled fractions include unconsumed abrasive particles and water, and waste fractions include depleted @ 磨粒And water; and (h) separation of the recycle fraction into water and separated unconsumed mill O: \ 71 \ 71287-911122.ptc Page 22 538112 _Case No. 90113718_ Modification __ VI. Patent Application Scope Particle suspension fraction. 16. The method according to item 15 of the scope of patent application, wherein the aqueous suspension is separated into a recycle fraction and a waste fraction by a hydrocyclone. 1 7. The method according to item 15 of the scope of patent application, which further comprises drying the separated unconsumed abrasive particles until the residual water content is less than 1000 ppm. 〇 1 8. The method according to item 15 of the scope of patent application Wherein the first corrosive agent dissolves the silicon particles in the first solid / corrosive mixture, the first corrosive agent includes water and a base selected from the group consisting of metal hydroxide and earth metal hydroxide, and the second liquid fraction includes The first etchant and the dissolved silicon particles. 19. The method according to item 18 of the scope of patent application, wherein the base is sodium hydroxide. 20. The method according to item 19 of the scope of patent application, wherein the concentration of sodium hydroxide in the first etchant is from 6 to 20% by weight. 2 1. The method according to item 19 of the scope of patent application, wherein the concentration of sodium hydroxide in the first etchant is from 8 to 15% by weight. 2 2. The method according to item 20 of the scope of patent application, wherein at least 6 liters of the first etchant are mixed per kilogram of the first solid fraction. 2 3. The method according to item 18 of the patent application scope, further comprising collecting the evolved hydrogen gas during the dissolution of the silicon particles in the first solid / etching agent mixture. 2 4. The method according to item 15 of the scope of the patent application, wherein the second etchant dissolves the metal particles insoluble in the first solid / corrosive mixture, and the second etchant O: \ 71W1287-911122.ptc Page 23 538112 _Case No. 90113718_Year_Month__ Sixth, the scope of the patent application includes water and an acid selected from the group consisting of nitric acid and sulfuric acid, and the second liquid fraction includes the first An etchant and dissolved metal particles. 25. The method according to item 24 of the patent application, wherein the acid is sulfuric acid. 2 6. The method according to item 25 of the scope of patent application, wherein the concentration of the first corrosive agent. Sulfuric acid is from 0.3 to 1% by weight. 2 7. The method according to item 25 of the scope of patent application, wherein the concentration of the first corrosive agent-, sulfuric acid is from 0.4 to 0.8% by weight. 28. A method of processing a depleted slurry for spin-slicing wafers. The depleted slurry includes a lubricating fluid, unconsumed abrasive particles, consumable abrasive particles, silicon particles, and metal particles. The method includes: (a) The depleted slurry is separated into a first liquid fraction and a first solid fraction. The first liquid fraction includes a suitable lubricating fluid. The first solid fraction includes unconsumed abrasive particles, depleted abrasive particles, and silicon. Particles and metal particles; (b) mixing the first solid fraction with water to form an aqueous suspension containing unconsumed abrasive particles, depleted abrasive particles, silicon particles and metal particles; (c) separating the aqueous suspension into Recycling fraction and waste fraction. The recycling fraction includes unconsumed abrasive particles, silicon particles, metal particles, and the waste fraction includes depleted abrasive particles, silicon particles, metal particles, and water; (d) the recycling grade With the first etchant to produce a first solid / corrosive mixture that dissolves the silicon particles or metal particles; (e) separating the first solid / corrosive mixture into a second liquid fraction and The second solid fraction, the second liquid fraction includes the first etchant and the dissolved silicon particles or the dissolved metal particles, and the second solid fraction includes the insoluble first corrosion O: \ 71 \ 71287-911122.ptc Page 24 538112 _Case No. 90113718_ Revised Year of the Year _ 6. Unconsumed abrasive particles and silicon particles or metal micro-materials for the scope of the patent application; (f) the second The solid fraction is mixed with a second etchant to produce a second solid / corrosive mixture in which silicon particles or metal particles insoluble in the first solid / corrosive mixture are dissolved; and (g) the second solid / corrosive mixture is separated into The third liquid fraction and > the third solid fraction, the third liquid fraction includes a second etchant and dissolved silicon-. Particles or dissolved metal particles, and the third solid fraction includes unconsumed abrasive particles. 2 9. A method for processing a depleted slurry for slicing a silicon wafer from a silicon ingot. The depleted slurry includes a lubricating fluid, unconsumed abrasive particles, consumable abrasive particles, silicon particles, and metal particles. The method includes : F (a) separating the depleted slurry into a first liquid fraction and a first solid fraction, the first liquid fraction including a lubricating fluid, and the first solid fraction including unconsumed abrasive particles, depleted abrasive particles, silicon Particles, metal particles, and lubricating fluid; (b) washing the first solid fraction with a solvent to reduce the concentration of the lubricating fluid in the first solid fraction, and generating a washing liquid containing the solvent and the lubricating fluid; (c) washing the liquid The first liquid fraction is added to generate a cleaning liquid / liquid fraction mixture, and the cleaning liquid / liquid fraction mixture is heated to a temperature from 50 ° C to 100 ° C to make the solvent self-cleaning liquid / liquid The fraction mixture is evaporated; (d) mixing the washed first solid fraction with an aqueous sodium hydroxide solution to produce a first solid / corrosive mixture in which the silicon particles are dissolved; O: \ 71 \ 71287-911122.ptc Page 25 538112 Case No. 90113718 Amendment VI. Patent Application Scope (e) Separating the first solid / corrosive mixture into a second liquid fraction and a second solid fraction, the second The liquid fraction includes an aqueous sodium hydroxide solution and dissolved silicon particles; the second solid fraction includes unconsumed abrasive particles, depleted abrasive particles, and metal particles; (f) mixing the second solid fraction with an aqueous sulfuric acid solution to Generating a second solid / corrosive mixture in which metal particles are dissolved; (g) separating the second solid / corrosive mixture into a third liquid fraction and a second solid fraction; the second liquid fraction includes an aqueous sulfuric acid solution and a hydrolyzed solution; Metal particles, the third solid fraction includes unconsumed abrasive particles and depleted abrasive particles; (h) washing the third solid fraction with water; and (i) drying the third solid fraction until the residual water content is less than 1000 ppm 〇3 0. The method according to item 29 of the scope of patent application, wherein The three solid fraction contains less than 7% by weight of spent abrasive particles. 3 1. A method for processing a depleted slurry for slicing a silicon wafer from a silicon ingot. The depleted slurry includes a lubricating fluid, unconsumed abrasive particles, consumable abrasive particles, silicon particles, and metal particles. The method includes (A) Separating the depleted slurry into a first liquid fraction and a first solid fraction. The first liquid fraction includes a lubricating fluid, and the first solid fraction includes unconsumed abrasive particles, depleted abrasive particles, and silicon particles. , Metal particles and lubricating fluid; (b) washing the first solid fraction with a solvent to reduce the concentration of the lubricating fluid in the first solid fraction, and generating a cleaning comprising the solvent and the lubricating fluid O: \ 71 \ 71287-911122.ptc Page 26 538112 _Case No. 90113Ή8_ Year, month, and year of amendment_ VI. Patent application scope fluid; (C) Add the cleaning fluid to the first liquid fraction to generate the cleaning fluid / A liquid fraction mixture, and the cleaning liquid / liquid fraction mixture is heated to a temperature from 50 ° C to 100 ° C to evaporate the solvent from the cleaning liquid / liquid fraction mixture; (d) The washed first solid fraction is mixed with an aqueous sodium argon oxide solution to produce a first solid / corrosive mixture in which silicon particles are dissolved; (e) separating the first solid / corrosive mixture into a second liquid fraction and a first Two solid fractions, the second liquid fraction includes aqueous sodium hydroxide solution and dissolved silicon particles; the second solid fraction includes unconsumed abrasive particles, depleted abrasive particles, and metal particles; (f) the second solid fraction Mixed with an aqueous sulfuric acid solution to produce a second solid / corrosive mixture in which metal particles are dissolved; (g) separating the second solid / corrosive mixture into a third liquid fraction and a third solid fraction, the third liquid fraction comprising Aqueous sulfuric acid solution and Dissolved metal particles, the third solid fraction includes unconsumed abrasive particles and depleted abrasive particles; (h) mixing the third solid fraction with water to produce an aqueous suspension containing unconsumed abrasive particles and depleted abrasive particles (I) separating the aqueous suspension into a recycle fraction and a waste fraction, the recycle fraction including unconsumed abrasive particles and water, and the waste fraction including consumable abrasive particles and water; and (j) separating the recycle stage Fractionation into a suspension liquid fraction comprising water and separated unconsumed abrasive particles; and O: \ 71 \ 71287-911122.ptc Page 27 538112 O: \ 71 \ 71287-911122.ptc Page 28