TW200841991A - Process and apparatus for treating exhausted abrasive slurries from the lapping process for the recovery of their reusable abrasive component - Google Patents

Abstract

Process and relative apparatus for recovering the reusable abrasive component contained in an abrasive slurry for the lapping of silicon wafers, or of quartz or ceramic components, when it becomes exhausted and enriched with undesired waste matter. The process, which uses wet size-sorting treatment carried out in a battery of hydrocyclones connected in series and operating in counter-current, possibly followed by chemical etching treatment in order to eliminate the fine iron particulate and, preferably, by a further wet size-sorting treatment carried out in a second battery of hydrcyclones connected in series and operating in counter-current, enables the complete recovery of the reusable abrasive grains contained in the exhausted slurry from the lapping process. These abrasive grains are the only recoverable component of this type of slurry because the suspending liquid consists of water and the suspension-stabilising additive is present in such low quantities that its recovery is not economically feasible.

Description

200841991 IX. Description of the invention: [Technical field to which the invention pertains] = A method and related apparatus for processing a polishing component discharged from a polishing program to recover a reusable slurry. More particularly: 'The present invention relates to a method for performing the method =: for when a slurry for grinding, quartz or ceramic wafers is discharged and is enriched with unwanted waste Recycling the contained in the slurry

Reusable grinding ingredients.哕太,,土 A, 刀@方, enough to be used in the discharge slurry from the polishing program, the king-grinding fine particles that are still used, and the fine particles are in this type of slurry. , m, ... Some reusable ingredients, this is the heart of the liquid is composed of water ^ 〇ΑΛ Θ ^ Wind and sweat additives are insufficient! The existence makes it possible to recover in an economical way. [Prior Art] As has been known, it is used in the field of V-European, private and first-hand volts, and the thinness obtained from the ingots or single crystal blocks. The disc ("Day ^ Day α α ) is cut vertically into its length to utilize the ingot. Typically, this 刼, 隹Α various slicing is made by a wire saw or a cutter to 仃 'in the line mine Or in the cutter and the h-knife in the system of the drum and the bobbin, the thousands of wires and the mechanically resistant metal wire are tied to the same B-inch to the length of the ingot. At the point where the cutting is carried out, it is in contact with the ingot. At the same time, the slurry containing the grinding, grinding, grinding, granules or granules (grinding pulp) is the contact between the cutting wire and the ingot. Area. For the use of wire saws to cut 矽, 石 々 α 或 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Water-soluble organic liquid of molecular weight (especially polyethylene glycol, PEG), which is generally suitable hardness of strontium carbide (Sic) The abrasive particles are suspended in the fluid. The rounds are then subjected to a polishing process to ensure the tight mechanical tolerances required by the microelectronics industry and to eliminate any damage to the lattice caused by previous cutting operations. And preparing a surface for subsequent polishing operations. The polishing operation is performed by a polishing machine consisting essentially of two large, completely flat and circular overlapping horizontal cast iron sheets, the plates Rotating in opposite directions to each other. The lower panel is evenly covered with a slurry, and the wafer from the cutting operation is placed on the lower panel and located in a special accessory device. They are thinner than the wafers to be polished, and they are made to rotate by the movement of the circular lower plate by the geared transmission system. The circle is then evenly coated to grind the slurry, and the upper plate The part is lowered onto us. This causes the whole system to rotate, and the slurry is in the grinding process: continuously feeds the space between the two plates from head to tail. The operation, '麄々 Until the wafer thickness required for microelectronics technology is reached. • The slurry used for the polishing process is instead made of deionized water (suspension =) through the oxidation of Al2〇3 and depending on the specific application required. An actual abrasive having a target particle size between ^ and 20 microns; and a commercially available mixture of added additives to form a suspension additive having the function of promoting and stabilizing the suspension of the abrasive particles in water. An amount in the range of 3 ^ 4 weight hundred a ratio is present in the suspension, and is generally a product of low economic value of 7 200841991, such that recovery from the discharged slurry is considered unworthy. The typical slurry composition of the germanium wafer is as follows: - deionized water 76.5% by weight - commercially available suspension additive 3.5% by weight - abrasive: pure alumina 20.0% by weight (with typical PW9 or PW15 particle size) or Mixing 200-300 g/L with other oxides - Suspension viscosity 450 cps During the polishing process, some of the fine particles will lose their use of $曰/土从, 曰 KA Dan for the process At first glance the soil with useful properties, it is because the alumina particles = research will be divided, particles, 1 and therefore no longer apply to the polished operations: grinding:! The fact that the size distribution of the granules is reduced to a lower average: the second wafer, and the thickness of the slab: from the second: when the thickness of the two is reduced, the part is the iron particle) and the 祷 被One hundred and eight l particles (size < 4 micron abrasive, iron) of the 100 parts of the solid portion of the piece (large in the discharge slurry) are about 3 percent.上 Above Surfaces are built and accumulated during the grinding operation. Because the fine particles are deposited on the surface itself, this is because they may be combined to = unwanted abrasive fines. (3) Knowing and knowing the bad party to the research program Q This is the 'disparity between the research and the research. The grinding and destruction of the square plate is no longer researched. The mechanical and chemical properties are no longer fresh and reused. According to the Qing, the % is used for the flow-out speed of the wafer during the other-lighting cycle and the mechanical parameter 8 200841991. It will negatively affect the efficiency of both the experimental viewpoint and the viewpoint of metallic contamination. Grinding 唠i έ<τ<& ί¥ , processed by the civil and 4 waste treatment plants. However, the resulting loach> is picked up to the landfill. In any case, except for the necessary disposal In addition to the % problem of the 仏 产物 product, there has been considerable economical _ convenience for the loss of the reusable abrasive granules contained in the slurry*. Reuse because they are still bran

扪1 has the correct size for further use in the slurry. Since the need to separate and recycle reusable abrasive components for use in the θ of the polishing program is a problem that is increasingly recognized in the art, several methods have been proposed for recycling the polishing process to remove the abrasive. Specific techniques of pulp, and they all versibly combine the following basic operations: a) by wet particle size far, especially by centrifugation or by passing the slurry through a hydrocyclone (entrained by liquid) The solid fine particle static separator, which uses the action of centrifugal force to separately grind the fine particles; ... destroys the undesired accumulation block of the abrasive fine particles by the drum screening method. As will be apparent from the following description of some embodiments of the prior art, there are various inconveniences, such as in terms of size or in the presence of fine flaws and/or iron particles, which can be reused. The quality of the ground fine particles is insufficient.曰本专利申请 JP 2003266309 (granted to Komatsu Denshi

Kinzokii KK) describes a system for automated recovery, recycling and feeding of slurry to a polishing machine, and for improving the grinding by destroying the accumulation of fine particles 9 200841991 v and eliminating foreign contaminated fines The production of light. The decomposition of the fine-grained accumulation block is carried out by a set of drum filters, and the discharged slurry from the polishing program is fed to the drum filters; the accumulated blocks of the fine particles are thus separated, and It is then separated with the aid of a recycled liquid. This liquid is capable of obtaining a suspension of abrasive fine particles having a suitable specific gravity' for reuse in a calender. The recycled liquid itself is capable of obtaining a second suspension containing abrasive fine particles (i.e., low specific gravity fine particles) and most of the pollutants such as iron and antimony, and the suspended matter can be subsequently Send to landfill for disposal. The separation system allows to eliminate the grinding accumulation block, but does not produce high quality recovery of the fine particles, because the recovered grinding portion still contains a fine polluted fine particles and fine powder (iron) And 矽), which accumulates in the discharged slurry to become a residue of the polishing program. Another program for recycling the slurry of the polishing program is described in the patent Shenyuemu JP 2002 239906 (Ishikawajima Hanyoki % = rV1Ce KK), which relates to the reuse of the slurry used in the polishing process. The method and related equipment, the method and related equipment can provide precise grinding of the fine particles and eliminate the abrasive fine accumulation block which may cause scratches and damage during the polishing operation. The method is based on separating the ground fine particles by centrifugation: the discharge grinding system from the grinding machine is fed to the first centrifugal separator, the first knife can remove the liquid from the polishing program The fine particles are ground and separated from the impurities. The ground fines of the first centrifugal separator are mixed with a liquid for washing and separating fine fine particles, and then fed into two continuous centrifugal separations of the fine particles which are separated from the cleaning liquid. Machines, such separators will therefore contain finely ground fines and impurities. The finely divided fines obtained from the two successive centrifugal separators were mixed with the grinding liquid obtained from the first centrifugal separator, and the thus obtained recovered suspended solids were fed into a polishing machine. In the method of the invention, the separation of the polishing component and the impurities from the liquid of the polishing program is carried out by a single centrifugal operation (first centrifugal separator). Therefore, it is expected that the grinding liquid, and thus the recovered suspension, will contain a kind of research and also contain such an impurity. SUMMARY OF THE INVENTION Based on this prior art, the object of the present invention is therefore to provide a method for processing a discharge slurry, the type of the slurry being used in a process of polishing a wafer by a polishing machine state, and The method can actually completely recover the finely sized abrasive particles that can be reused in the grinding light private sequence in an economically viable process that is easy to operate. The method also necessitates ensuring that the recovered and reusable ingredients completely eliminate the waste from the polishing process (such as tantalum and iron from cast iron plates from the polishing machine) and destroy the abrasive materials that are no longer usable. Fine particles. Starting with the specific requirements of the slurry used in the polishing of recycled germanium wafers, the slurry typically has the following characteristics: • Abrasives: pure alumina or a mixture with other oxides, having 4 and 2 0 Particle size between microns; • Suspended liquid: deionized water; 200841991. Additives: Commercially available types with high suspension capacity;

The object of the present invention is to apply a technique similar to that which has been used to treat discharged slurry from a crucible, quartz or ceramic ingot cut by a wire sawing cutter. The inventor remains the target of the unpublished patent application RM2005 A000329. The technique used to recover all the useful ingredients from the cutting stone wafers is (4) more complicated. 'This technology contains a part of the grinding component that is suitable and beneficial for the recovery of the polishing program. Wet particle size sorting in a hydrocyclone separator is subjected to separation by removing the reusable abrasive fines from the remainder of the material, which is optimally not in a single-hydrodynamic force. It is implemented in a cyclone separator, but in a group of hydrocyclones that are suitably connected in series and fed in countercurrent. As is known, in a hydrocyclone, the feed to be treated is fed into the apparatus at high speed and tangentially from the top such that centrifugal forces push the heavier particles toward the sides of the container. Moving in a spiral, the heavier particles are then collected in the conical bottom (underflow) of the vessel, while the purified liquid exits from a central conduit (overflow) at the top. In the proposed hydrocyclone separator group, the abrasive-rich fines obtained from the bottom of the hydrocyclone and like the overflow (UF) are transferred to the next hydrocyclone fed into the series. The bottom of the hydrocyclone in the flow separator, and later the hydrocyclone, produces a suspension of ground fines suitable for re-use sizes. Other technical features of the 12 200841991 wheel described in the patent application RM2005 A000329 can also be used in accordance with some preferred solutions of the procedure that can be conceived in the present invention. In particular, the objective of the acid leaching treatment carried out on the fine granules obtained from the hydrocyclone separator group as the underflow flow is: 'Yes still 3' recovered in the operation of the hydrocyclone group The chemical residue of the fine iron particles in the fine particle feed is milled, and in some cases, the operation of filtering the suspended fines recovered by chemical silver engraving. Accordingly, the present invention specifically provides a method for treating a slurry discharged from a polishing program φ, and the slurry is composed of a suspension liquid, and reusable abrasive fine particles, fine abrasive fine particles, and fine stone eve It is composed of fine particles and fine metal fine particles, and the suspension liquid is basically composed of water and an additive for stabilizing the suspension. The method comprises the steps of: a) separating the discharged slurry by a wet particle size sorting process: i) a liquid suspension containing reusable abrasive fine particles, and π) a fine abrasive fine particle, And a liquid suspension of fine fine particles and fine metal fine particles. _ b) eliminating the liquid suspension containing the fine fine particles and the fine fine particles and the fine metal fine particles, and collecting the liquid suspension containing the reusable abrasive fine particles to feed them back to the polishing program in. The method is characterized by the fact that the wet particle size sorting process of operation step a) is carried out by treating the mixture in at least two first group of hydrocyclones connected in series for countercurrent feeding Water is introduced whereby a liquid suspension is obtained from the bottom of the last hydrocyclone of the group, the liquid suspension containing reusable abrasive fines and negligible amounts of fine abrasive fines. Preferably, the first group consists of a hydrocyclone separator between two and six 13 200841991, but preferably a flat raft 1 land 疋 four hydrocyclones separated

Fine particles. The acid reagent can be selected from the group consisting of nitric acid, hydrochloric acid, oxalic acid, sulfuric acid, a mixture thereof, and the method of representing the simplest version of the method according to the present invention, the potting system uses fine iron in the recovered grinding component. When the final concentration of the particles is not important. According to a first preferred variant of the method proposed by the invention, the liquid suspension comprising reusable abrasive fines obtained from the bottom of the last hydrocyclone of the first group is further processed for By adding an acid reagent solution to the liquid material containing the reusable abrasive fine particles, a micro-fine iron fine particle purified by chemical etching is obtained, and the acid and the acid reagent are excessive. It is used such that the discarded effluent liquid obtained by the treatment may contain iron salts derived from the acid leaching operation, together with excess acid and any fine iron residue. According to a preferred version of the method, after the addition of the acid reagent solution, the liquid suspension containing Φ reusable abrasive fines is subjected to further wet particle size sorting treatment, which is also connected in series by One of the at least two hydrocyclone separators is treated with the mixture and fed in countercurrent. A liquid suspension containing reusable abrasive fines and substantially no fine, non-usable abrasive fines obtained from the last hydrodynamic swirl of the second group as the bottom of the alien. The top of the first hydrocyclone of the second group produces a liquid suspension of fine iron particles, excess acid, and iron salts, which are discarded. Even with the second group of hydrocyclones, the number of water connected in series 14 200841991 is usually between two and six hydrocyclophonic separations and preferably four A hydrocyclone separator.

According to a different variant of the method, it is equivalent to the first AI in terms of results, and after the addition of the acid reagent solution, the liquid suspension containing the reusable abrasive granules is subjected to -W by adding human water. Thereby, a solid phase containing reusable abrasive fine particles and substantially no fine abrasive fine particles is obtained in the baking cake. The filtrate from this filtration operation produces an excess of liquid suspension of acid and iron salts which is discarded. The abrasive fines produced by the method according to the invention are suitable for repeated use in the polishing process and for this purpose 'preventively placed after the addition of the required amount of water and fresh stabilizing additives A suspended mature matte with a shaking mechanism. The thus obtained grinding suspension can be mixed with an appropriate amount of fresh slurry before use, and the entire batch is fed in the polishing process. According to another aspect, the present invention is directed to an apparatus for processing a slurry discharged from a polishing program according to the foregoing procedure, the apparatus consisting of the following elements interconnected in sequence: the next hydrocyclone The recirculating overflow flow is fed to the next hydrocyclone. ϊ· at least two hydrocyclone separators connected in series by the first group, and feeding the water in a countercurrent flow to the first hydrocyclone separator to feed the discharged slurry, and each hydrocyclone is separated The underflow system of the device, together with the II.-storage tank, is equipped with a rocking mechanism for preparing a polishing slurry that will be reused in the polishing program. 15 200841991 - A storage tank equipped with a rocking mechanism for maturing the recovered suspension. Preferably, there is a reservoir upstream of the reservoir having a rocking mechanism for preparing a polishing suspension liquid to be reused in the polishing program, and a rocking mechanism having a chemical etching for fine iron particles. And at the downstream of the chemical tank for the fine iron particles, there is a second group of at least two hydrocyclone separators connected in series, and the water system is fed in countercurrent, wherein the first hydrocyclone is separated The device is fed with the discharged slurry, and the underflow flow system of each of the cyclone (four) devices is fed into the next hydrocyclone separator together with the recirculation overflow of the next external hydrocyclone separator. Among them. The suspension from the bottom of the last hydrocyclone is fed into a reservoir with a shaking mechanism for preparing the polishing suspension to be reused. According to an implementation version of the apparatus configuration in which the filtration operation is used in place of the second group of hydrocyclones, a filter device is provided downstream of the (four) for the chemically engraved fine iron particles, from which the excess is acid A purification liquid system consisting of _ and a liquid suspension of iron salts is discarded. The obtained filter cake containing reusable abrasive fines is fed into a storage tank having a shaking mechanism for preparing a polishing suspension to be reused. [Embodiment] As shown in the block diagram of the main reference configuration of Fig. 1, the process according to a preferred variant of the present invention is basically composed of three segments: a group: a force cyclone separator - chemical etching • The second group of hydrocyclone separators. When the final concentration of iron in the recovered abrasive component is important, the configuration shown in Figure 16 200841991 is used, and the configuration basically consists of the following operations: a) Collecting the grinding machine from the inside of the container called the storage tank 1 This is necessary to discharge the slurry because the process can be implemented in either continuous mode or batch mode depending on the desired process configuration; in the figure, the process is continuous. b) separating the discharged slurry into two components, which are carried out by wet particle size sorting in a first set of hydrocyclone fed in countercurrent: • Underflow (UF) suspension It contains abrasive fines (> 4 microns) reusable in suspension liquid; fine iron particles are still present, up to the order of 1000-1500 parts per million. • An overflow (O.F.) suspension containing non-reusable ground fines (<4 microns), fine fines of cerium and iron, and additives contained in the discharged grinding slurry. c) Collecting the UF. suspension from the group of hydrocyclone separators of operation b) in a vessel called tank 2 for use as a regrindable grinding component (>4 A storage tank for the suspension of micron) is used. d) An acid reagent solution (oxalic acid, sulfuric acid, hydrochloric acid or other acid) is added to the tank 2 as c) to further reduce the concentration of fine iron particles. e) Separating the reusable slurry contained in the tank 2 into two types of knives. This separation is carried out in a second group of hydrocyclone separators by wet particle size sorting: Lower Secret Stream (UF· The suspension "containing fine particles (> 4 micrometers) which can be reused in a suspension liquid, wherein the fine iron particles are reduced to 100-500 of 2008. A fine iron particle suspension of the upper machine (〇.F) containing an excess of acid and iron salts and discarded. The slurry having / reusable abrasive fines (> 4 mils) is collected in a mixture to prepare the regenerated suspension, and then water and the additive are added. g) The regenerated milled aggregate is transported to a vessel known as tank 3, wherein the suspended solids are kept under shaking and stabilized. h) mixing the suspended solids in the internal tank 3 with the suspension prepared from the freshly ground material, and then transporting the resulting abrasive package to a polishing machine for use. Alternatively, the final product of the same qualitative feature can be obtained by a process carried out according to the condition of Figure 2, which consists essentially of three sections: a first set of hydrocyclones _ chemical etching _filter. When the final concentration of iron in the reusable grinding component is important, use the configuration shown in Figure 2 instead of -, the following operations are involved. · kg - and the configuration is basically a) in a tank 1 The inside of the container receives the discharge grinding device from the polishing machine, which is necessary because the process can be implemented in either a continuous mode or a batch mode depending on the desired setting; The process is batch-based. Figure 2 Separates the discharged slurry into two components. This separation is carried out in the first group of hydrocyclone separations fed in countercurrent. The process is now carried out in a wet particle size sorting process. 18 200841991 • Down / slave纟, L (UF·) suspension containing reusable grinding in suspension liquid is fine (> 4 microns); fine iron particles are still present and are as high as 1000-1500 parts per million. • An overhead turbulent (O.F.) suspension containing non-reusable ground fines (<4 microns), fine fines of cerium and iron, and additives contained in the discharged slurry. c) Collecting the UF•suspension from the group of hydrocyclone separators of operation b) into a vessel called tank 2, which is used to contain reusable grinding components (>4 A storage tank for the suspension of micron) is used. d) An acid reagent solution (oxalic acid, sulfuric acid, hydrochloric acid or other acid) is added to the tank 2 of operation c) to further reduce the concentration of fine iron particles. e) separating the reusable slurry contained in the storage tank 2 into two components, the separation being carried out in a second group of hydrocyclones by wet particle size sorting: liquid phase, which is It consists of water, an excess of acid and an iron salt of the acid, and is discarded. The mouth phase is composed of alumina fine particles of size > 4 microns and residual fine iron particles, and the residual (4), iron suspension is within the limit of 0-500 parts per million U. The solid obtained by the operation in e) is decoupled from the water and the addition of σ to obtain a reusable oxidized fine particle (> 4 μm) suspension in water. g) The regenerated milled aggregate is transported to a vessel, referred to as tank 3, wherein the suspension is maintained under shaking and stabilized. 19 200841991 h) The suspended solids contained in the storage tank 3 are mixed with the suspended solids prepared from the fresh abrasive material, and then the resulting slurry is transported to a polishing machine for use. The process produced in accordance with the configuration illustrated in Figure 3 is a simplification of the foregoing two configurations and consists solely of the first set of hydrocyclones; this process is used when the initial concentration of iron in the abrasive component is not critical. In this case, the process consists of the following operations: 4 It is necessary to receive the discharged slurry from the polishing machine inside a container called the storage tank 1, which is necessary because the process can be approximated to the required process configuration. It is implemented in either continuous mode or batch mode; in Figure 3, the process is continuous. Cloth b) separating the discharged slurry into two components, the separation being carried out in a first group of hydrocyclone fed in countercurrent by wet particle size sorting treatment: a sub-overflow (UF) suspension Resin containing reusable finely ground (> 4 microns) in suspension liquid; fine iron particles are still present and are as high as 1000-1500 parts per million. 〇 α (αρ·) suspended matter containing fine particles (<4 μm) which are not reusable, fine fine particles of bismuth and iron, and additives in the slurry. Is the suspension of the hydrocyclone of the set of hydrocyclones from the grinding operation b) again: in a vessel with a "reservoir 2, which is used as a suspension for containing reusable grinding components (4) micron) The storage tank of the material is used. d) The regenerated slurry obtained in this way is referred to as the tank 3 20 200841991 σ 〇 where the suspension/prey is kept under shaking and can be stabilized. The suspended solids in the storage tank 3 are mixed with the suspension prepared from the fresh abrasive material, and then the generated abrasive is collected and transported to a polishing machine for use. The hydrocyclone separation shown in Fig. 4 can be used. Group configuration for reusable abrasive fines (size < 4 microns) from already used and non-reusable abrasive fines (size > 4 microns), and fines from iron and tantalum Separation of the granules. The first group of first hydrocyclone separators are fed with a discharge slurry mixed with the overflow flow of the second group of hydraulic cyclone separators. The first group of hydrocyclone separators Generating an overflow suspension and an overflow suspension, the underflow The float system is fed to the second hydrocyclone separator; and the overflow overflow material contains fine particles of size < 4 microns, fine fine particles of iron and stone, and additives present in the discharged slurry. And being disposed of and sent to a waste treatment plant. The second hydrocyclone is an underflow of the first hydrocyclone separated from the overflow suspended matter above the third hydrocyclone. Suspended _ material feed; the overflow stream suspended by the second hydrocyclone is fed into the first hydrocyclone, and the underflow suspension is fed into the third hydrocyclone The third hydrocyclone is fed by the overflow suspension under the second hydrocyclone mixed with the overflow suspended matter above the fourth hydrocyclone; the third hydrocyclone The overflow overflow generated by the separator is fed into the second hydrocyclone, and the underflow suspension is fed to the fourth hydrocyclone. 21 200841991 The fourth hydrocyclone is Underflow of a third hydrocyclone with a water prevention ground The suspended matter is fed; the overflow overflow generated by the fourth hydrocyclone is fed into the third hydrocyclone, and the reusable abrasive granules having a size of > 4 microns are The underflow suspension of iron content within the limits of 1000-1500 parts per million is transported to the collection tank 2. The second group of hydrocyclones shown schematically in Figure 5 is used for Combined with the separate centrifugation of the hydrocyclone and the chemical etching activity of the acid on the iron-based particles, the iron content in the reusable slurry is further reduced. The first of the second group of hydrocyclones The hydrocyclone separator is fed with reusable grinding suspension from the reservoir 2 and mixed with the overflow above the second hydrocyclone. The first hydrocyclone produces a helium overflow. The flow suspension is an overflow suspension which is fed into a second hydrocyclone separator; the overflow suspension contains fine iron particles and excess acid which are eliminated and discarded. . The two hydrocyclone separations of the second group of hydraulic cyclones are separated by the first hydrocyclone separated by the overflow of the third hydrocyclone. Suspended matter feed; the overflow overflow suspended by the second hydrocyclone is fed into the first hydrocyclone, and the underflow suspension is fed into the third hydrocyclone Device. The third hydrocyclone is fed by an underflow suspension of a second hydrocyclone that is mixed with the overflow suspension above the fourth hydrocyclone; by the third hydraulic Overflow sag generated by cyclone separator 22 200841991

The oceanic system feeds into the second hydrocyclone and the underflow suspension is fed to the fourth hydrocyclone. The fourth hydrocyclone is fed by an underflow suspension of a third hydrocyclone that is preventively mixed with water; an overflow overflow generated by a fourth hydrocyclone The system is fed into the second hydrocyclone, and the abrasive fines having a size of > 4 microns can be re-flowed, and the underflow suspension having an iron content within a millionth of a value is It is transported to the collection tank 2 where the suspended solids are prepared by adding water and an additive. As can be seen from Liwen, the object of the process according to the invention is to achieve a result which is advantageously applied to the field of recycling abrasive fines from the polishing process, ie a patent application similar to the common patent RM2〇〇5 A The technique described in 〇〇〇 329. The main differences between the two methods are as follows: a) The present invention is applied to discharge slurry from different processes (sintering instead of cutting), using a different type of grinding component (oxidized or oxidized color, Instead of carbonized stone, a different supporting liquid (water, rain is not polyethylene glycol or oil), and different additives. b) 'The process phase and the relative configuration have the following main differences. · a. The hydrocyclone separator of the previous process, the underflow system of the group is fed into a special filter system. The filter system is located in the same device. Also known as the residual residue, washing, chemical 巍钊,: set ^ no buttoning to the washing and drying of the etching filtrate, but the name

In J private, the first group of hydrocyclone separated and cried. The turbulent flow from the moxibustion is fed into one of the subsequent I-flows, which depends on the degree of iron contamination that can be received in the V and U-receiving components: followed by the chemical I· The second group of hydrocyclones was etched in 23 200841991 (Fig. 1). π· is followed by a chemical etch after the filtration operation (Fig. 2). HI • Or even directly to prepare the suspension by recovering the abrasive components without any chemical etching operation (Fig. 3). b. Overflow of the hydrocyclone separator group of the prior patent application to filtration, microfiltration, distillation, and finally filtration to recover suspended fluid (polyethylene glycol or oil) and completely eliminate Fine particles, while in the present invention, the overflow of the first and second sets of hydrocyclones directly is discarded (the fluid of the suspension is water and therefore not recovered). c. The process of the present invention can be carried out in one of a continuous mode or a batch mode, depending on the flow configuration used, whereas the process in the prior patent application is only in a continuous mode. The present invention has been specifically described with reference to the particular embodiments thereof, and it is understood that those skilled in the art can make modifications and changes without departing from the scope of the invention as defined by the appended claims. [Simple description of the drawing] The specific times $, ν β of the present invention will be more obvious than the old _ /, advantages and related operational patterns, a#, which are only for the purpose of the |7 乍 且 且Some of the ', ', are described in the accompanying drawings, in which: "" and Wang Xian. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an overall block diagram of a process for treating a refining slurry according to the present invention in the form of the rt ^ ^ ^ 4 / 3 discriminating form; An overall block diagram of a process for treating the refining process of the Exhaustion 24 200841991; FIG. 3 shows an overall block diagram of a process for treating the discharged slurry according to a third implementation form of the present invention; FIG. 4 shows the first group A simplified garment arrangement of a hydrocyclone coupled in series, which represents a major section of the configuration; and Figure 5 shows a simplified arrangement of a second set of hydrocyclones connected in series, which is representative of A preferred addition section of the configuration.

[Main component symbol description] 1 Storage tank 2 Storage tank 3 Storage tank 25

Claims (1)

200841991 X. Patent application scope: /· - A method for treating water discharged from a polishing program and comprising a suspension liquid grinding water, the suspension liquid is basically composed of water and a floating material additive, and can be reused for grinding. Granules, fine grinding: granules, J: cerium particles and fine metal particles, the method comprises the following steps: a) grinding a discharge by a wet particle size sorting process 4 t -r π i } ^ a liquid suspension having reusable abrasive fine particles, and Η) a liquid suspension containing 1 abrasive fine particles and the fine fine particles and fine metal particles; the removal includes the fine abrasive fine particles and the like a liquid suspension of fine granules and fine metal particles, and collecting a liquid suspension containing the aforementioned reusable abrasive granules for feeding back to the polishing program; = the method is characterized by the fact that the aforementioned operation a The wet granule bifurcation 4 treatment is achieved by treating the mixture in a first set of at least one hydrocyclone separator connected in series with countercurrent feed water, thereby separating from: At the bottom of the vessel is obtained a liquid suspension comprising reusable abrasive fines and negligible amounts of fine abrasive particles. 2 · As claimed in the patent range, the jth cyclone separator consists of a series connected device. The method of the item, wherein the first group of hydraulic forces is between 2 and 6 hydrocyclone separations 26 200841991 4. The method of claim 3, wherein the method comprises the last hydrocyclone from the first group The aforementioned liquid suspension of the reusable abrasive fines obtained at the bottom is further processed to chemistry by adding an acid reagent solution to X containing reusable &amp; fine particles of pre-pigment suspension Etching to obtain abrasive fine particles without traces of fine iron particles. 5. The method of claim 4, wherein the acid reagent is selected A group consisting of free, hydrazine, hydrochloric acid, oxalic acid, sulfuric acid, citric acid, and fruit acid or a mixture thereof. 6. The method of claim 4, wherein the liquid suspension containing the reusable abrasive fine particles is passed through a series connection of countercurrently fed water after the addition of the acid reagent solution. a second group of at least two: a hydrocyclone separator and receiving a step-by-step wet particle size sorting treatment, and obtaining a reusable abrasive fine particle from the bottom of the second group of the last hydrocyclone separator In essence, there is no fine liquid suspension of fine particles that can no longer be used. 7. The method of claim 6, wherein a liquid suspension of fine iron particles, excess acid, and iron salt is obtained from the top of the second group of first hydrocyclone separators, and the system is discarded. . 8 · For example, Shen Qing patent scope item 6 戋 7th jg + i, one whistle: 3⁄4 brother 7 item, wherein the second group of hydrocyclone separators are 2 to 6 by stringer _ 迓The hydraulic square turbulence separator is constructed between. 9. As claimed in the patent scope, the cyclone separator is constituted by a method in which one item is connected in series, wherein the second group of hydraulic four hydrocyclone separators. The method of claim 4, wherein the liquid suspension containing the reusable abrasive fine particles is subjected to the addition of water after the addition of the acid reagent solution. A filtration operation whereby a solid phase comprising the reusable abrasive fines and substantially no fine abrasive fines that are not reusable is produced in the filter cake. 11. The method of claim </ RTI> wherein the filtrate of the filtration operation produces a liquid suspension of excess acid and iron salts, and the graft is discarded. The method of any one of the preceding claims, wherein the reusable abrasive fine particles are retained in a shaking tank for maturation of the suspension for a period of time. Feedback to the research program. 13. The method of claim 12, wherein the grinding fine particles are fed back to the polishing process after the addition of the slurry in the required amount prepared by freshly grinding the material, water, and fresh stabilizing additive. in. Lu 14. A device for treating a discharged slurry from a polishing program according to the method as defined in claim 1 of the patent application, the device comprising the following elements interconnected in sequence: I. feeding water in countercurrent a first group of at least two hydrocyclone separators connected in series, wherein the first hydrocyclone separator is fed by the aforementioned discharge slurry, and each hydraulic cyclone separator overflows p hydraulic power The recirculation overflow of the cyclone separator is fed into the next hydrocyclone &amp;amper;&amp; 77 II. A tank equipped with a shaking mechanism for preparation will be reused in the study of the optical path 28 200841991 The light-filling device, used to make the recovered suspension πι·- a tank with a shaking mechanism mature. 'Where there is a storage tank equipped with a rocking mechanism for chemical 15 · as claimed in the 14th article of the patent application 】 Preparing a slurry-type storage tank to be reused in the polishing program, there is a 1 ancient h 'one with a shaker machine damage etched fine iron particles. 1 6 ·If the scope of patent application is 丨5 The money is engraved with small iron particles. The mouth is placed in the second stage of the chemical. The water is fed in a countercurrent flow, connected in series with a two-hydrocyclone separator, and the first one is hydrodynamic. ~ For example, (investigation of submersible feeding, and each hydrocyclone is divided into melons and the next hydrocyclone separator is fed into the lower hydrofluidic separator, and finally the hydrocyclone The warm flow system above the separator feeds the storage tank with the shaking mechanism, and the core prepares the reused polishing slurry. 17. The device of claim 16 of the patent application, wherein the storage tank for chemically engraving fine iron particles There is a filter and device downstream from the filter, the device is discharged. The purification system of a liquid suspension of excess acid and iron salt is discarded, and the obtained reusable abrasive fine particles are obtained. The cake is fed into a storage tank with a shaking mechanism for preparing a re-use of the polishing light. XI. Round: as shown in the next page 29