201217515 六、發明說明： 【發明所屬之技術領域】 本發明是關於一種矽晶切割液的回收方法，特別是指 一種利用溶解度差回收矽晶切割液的方法。 【先前技術】 一般矽晶棒多是利用多綠+„攸七a “201217515 VI. Description of the Invention: [Technical Field] The present invention relates to a method for recovering a twin crystal cutting liquid, and more particularly to a method for recovering a twin crystal cutting liquid by using a difference in solubility. [Prior Art] Generally, the strontium rods are mostly green + „攸七a”
• 4裂的情形’因此⑪晶棒在切割過程中會使用具有潤滑及 冷卻作用的切割液，以降低切割過程的機械應力和熱應力 損害；此外，切割液對高硬度的碳化矽砥粒具有良好的分 性。然而，矽 與切削損失的 散性，可進一步提升矽晶棒切割製程的穩定性 晶棒切割後’大量的切割液、高硬度砥粒，與 石夕、鋸線金屬等物質混合後，會形成泥漿狀的切割廢液排 出，導致晶圓製造產業必須面對大量待處理的廢液問題， 一方面製造成本驟增；另外， 淨能源的精神》 更运者了以太陽電池作為潔 由目前切割廢液成分分析可知，其含有的聚乙二醇類 (Polyglycols)切割液約占3〇 wt%_5〇 wt% ’而其餘的固體微 粒主要疋由粒度5-15 v m的碳化碎低粒，以及粒度〇丨$ v m 切削損失的矽，0.5-2/z m來自於不鏽鋼鋸線的金屬微粒等物 質。事實上，雖然這些聚乙二醇類溶液混合了其他固體顆 粒，以泥漿狀態排出，但是其性質仍十分穩定，具有極高 的回收價值。隨著近年矽晶需求量大增，切割液的價格也 201217515 急遽攀升’因此各麻家爭相研發相關流程或方法，以回收 此具有兩經濟價值的切割廢液。 例如，中國大陸CN101239246公開號專利揭示一種回 收矽晶切割液的方法，其主要是利用先加入5〜5〇%的分離 劑於切割廢液中，利用機械分離方式將其分成50〜95%的富 碳化矽漿料，及5〜50%的貧碳化矽懸浮液，接著在貧碳化 矽懸浮液中加入穩定劑，並在7〇~13(rc的溫度下反應丨〜以 小時，反應完後冷卻至適合機械過濾的溫度，濾掉貧碳化 矽懸浮液的固體顆粒，而得到回收的切割液；此外，在中 國大陸CN101474511公開號專利則揭示另一種回收矽晶切 割液的方法，其主要是利用先加入約為切割廢液的3 5〜4 5 倍的降黏劑於切割廢液中，利用多次過濾方式將固體顆粒 移除，最後再將過濾得到的三級懸浮液利用真空蒸餾方式 得到可循環使用的聚乙二醇和蒸餾液。 由前述說明可知，目前矽晶切割液大都是利用多次直 接過濾方式將切割廢液中的固體微粒與切割液分離或是 利用加入穩定劑或降黏劑，先令切割廢液黏度降低，將切 割廢液中的固體微粒濾出，再使用蒸餾方式將切割液分離 出；然而，由於切割廢液的黏度甚較高，利用直接過濾的 方式將切割廢液中的固體微粒與切割液分離，不僅需使用 高馬力抽氣幫浦輔助，其處理成本高且費時，並且濾材容 易損毀；加入降黏劑後雖可以減少過濾的時間，但後續利 用蒸德方式回收的切割液’則因為蒸餾的持續高溫，容易 造成切割液氧化變質的問題。此外，利用減壓或真空蒸傭 201217515 的方式雖然有助於在較低溫度下去除混入的降黏劑，但是 需使用減壓抽氣等裝置，並且去除速度緩慢、不易控制回 收切割液的含水量等問題，也導致切割液再利用的效能遞 減。因此，如何發展一簡便、經濟，且可有效回收矽晶切 割液的方法’仍然為目前業界不斷努力開發的方向之一。 【發明内容】 因此，本發明之目的，即在提供一種簡單且可快速回 收梦晶切割液的方法。 籲 於疋’本發明為一種矽晶切割液回收方法，包含一稀 釋步驟、一固液分離步驟，及一加熱分相步驟。 該稀釋步驟是將一切割矽晶後含有碳化矽、矽與金屬 等固體微粒和切割液的切割廢液加入重量百分比不小於該 切割廢液的l〇wt%的水，稀釋後形成一混合廢液。 该固液分離步驟是將該混合廢液進行固液分離，使混 合廢液中的固體、液體分離，得到一含水切割液。 該加熱分相步驟是將該含水切割液加熱至溫度不小於 籲 45 c的條件下，令該含水切割液中的切割液和水藉由溫度 變化k成溶解度變化，而令該切割液與水形成不互溶的切 割液相與水相，之後將該切割液取·出，得到一回收切割 液，即完成該矽晶切割液回收方法。 本發月之功效在於：利用溫度控制，令原本室溫下互 '今的切割液與水形成不互溶的切割液相與水相，即可將切 J液刀離出，不僅方法簡單’不需使用高耗能且昂貴的設 備且可以决速去除大量的水，所回收的切割液含水量低 201217515 且穩定，因此回收再利用效能甚高。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之一個較佳實施例的詳細說明中，將可 清楚的呈現。 本發明矽晶切割液回收方法的一較佳實施例，包含一 稀釋步驟21、一固液分離步驟22 ’及一加熱分相步驟23。 該稀釋步驟21是將一切割廢液加入重量百分比不小於 該切割廢液10wt%的水，稀釋後形成一混合廢液。 該切割廢液是利用切割液混合高硬度碳化碎紙粒形成 研磨聚液後’配合不錢鋼鑛線切割碎晶棒後收集而得，其 中3有液體及固體微粒兩大部分’液體主要是聚乙二醇類 切割液’而固體微粒則為研磨漿液中的碳化矽顆粒與切削 損失的多晶矽或單晶矽顆粒、鋸線金屬等物質。於本實施 例中’該切割廢液中的固含量約700 g/L。 由於混合了大量固體微粒後的切割廢液黏度甚高，導 致後續固液分離操作困難。因此，該稀釋步驟21要先加入 室溫下與該切割液互溶的水，將該切割廢液的黏度降低， 而得到一具有低黏度的混合廢液。 值得一提的是，於室溫下，當加入該切割廢液的水量 低時，由於水與切割液的主要成分聚乙二醇類化合物之間 會產生氫鍵，導致形成分子間鍵結而延長其分子鏈，反而 會造成混合廢液加入少量水後黏度上升；因此，加入切割 廢液的水量要不小於該切割廢液的1〇wt%，以得到一具有 201217515 低黏度的混合溶液；較佳地，該加入的水量不小於該切割 廢液的30wt%，更佳地，該加入的水量不小於該切割廢液 的50wt%，且形成的混合廢液黏度不大於該切割液的黏 度。 該固液分離步驟22是將前述該混合廢液進行固液分 離，並控制所分離出的含水切割液固含量不大於1〇g/L。 該步驟22可經由沉降池、濃集機、離心或過濾等方 式，令該具有低黏度的混合廢液進行固液分離，而得到一 • 固含量不大於i〇g/L的含水切割液。於本實施例中，是利 用沉降方式，將低黏度的混合廢液放入沉降池中靜置，待 固體微粒沉降，而得到一具有低固含量的含水分割液。 由於該混合廢液是經水稀釋後的低黏度液體，因此， 於靜置10 hr後，即可觀察到明顯的固液分離界面’並足以 取得大量固含量不大於l〇g/L的含水切割液；靜置時間愈 久，固液分離界面愈清楚，所取得的含水切割液的固含量 愈低，較佳地，靜置24 hr後，固體微粒更大量的沉降；更 ® 佳地’靜置48hr後，大多數粒子均已沉降到池底。要說明 的疋，當該含水切割液的固含量大於1〇g/L時，在後續的 相分離過程中，會因為該些固體微粒在加熱過程中形成對 流擾動效應的干擾，以致於無法有效地令該切割液與水形 成不互溶的兩相，進而影響該切割液的回收效能。 該加熱分相步驟23是將該含水切割液加熱至溫度不小 於45°C的溫度條件下，而令該切割液與水形成不互溶的切 割液相與水相，將該切割液與水進行分離，而完成切割液 201217515 的回收。 常壓下，該含水切割液中的聚乙二醇類化合物和水在 室溫時，由於會產生氫鍵作用，因此可彼此互溶形成均相 洛液，而當溫度升高時，則由於該含水切割液的聚乙二醇 類化合物與水之間的氫鍵被破壞，所以聚乙二醇類化合物 於水中的溶解度因此下降。本發明即藉由水與該聚乙二醇 類切割液之間因溫度變化而造成溶解度變化的特性，提出 一種簡單且可快速回收石夕晶切割液的方法。利用水稀釋固 含量高的切割廢液，藉由水與聚乙二醇類切割液於常溫下 互溶性高的性質，大幅降低切割廢液的黏度，以使切割廢 液中的固體微粒有效的在固液分離過程中移除，獲得固含 量不大於l〇g/L的含水切割液；接著，再利用溫度控制， 將含水切割液的溫度提升到不小於45^，藉由升溫破壞含 水切割液中的聚乙二醇類化合物與水之間的賴，而讓聚 乙二醇於水中的溶解度下降，進而發生相分離，形成不互 溶的兩相（切割液相和水相），如此不需使用將水氣化的耗能 單元，亦不需要藉助昂貴的抽氣裝置，即可將此主成分為 聚乙二醇類的切割液回收。 較佳地，該加熱分相步驟23是在溫度不小於5〇<t的條 件下進行；更佳地，該加熱分相步驟23是在溫度介於 5〇〜70 C的溫度條件下進行。經檢測由本發明該較佳實施例 回收後之回收切割液的含水量（水分滴定儀，Metr〇hm 87〇 F Titrino plus)及黏度（黏度計，Br〇〇kfieid LVDV-E，25。〇 後，得到其水分含量在〇 2_2wt%，且其在25它的黏度與原 201217515 始切割液相比波動約在1-4%之間。 ^综上所述，本發明藉由水與聚乙二醇類切割液在不同 溫度下的溶解度特性，利用水為稀釋液，藉由水與聚乙二 醇類切割液於常溫下的互溶性，大幅降低切割廢液的黏 度因此，可有效率地將切割廢液中的固體微粒移除；再 利用溫度控制，破壞聚乙二_切割液與水之間的氣鍵， 而讓切割液於水中的溶解度下降’發生相分離，進而形成 不互溶的兩相，即可將聚乙二醇類切割液回收再利用。不 僅方法簡# ’並且不需抽氣裝置，或蒸發、蒸傲等高耗能 且昂貴的設備，可以較快的去除大量的水，所回收的切割 液s水量低且穩疋，故雄實能達成本發明之目的。 惟以上所述者，僅為本發明之較佳實施例與具體例而 已，當不能以此限定本發明實施之範圍，即大凡依本發明 申請專利範圍及發明說明内容所作之簡單的等效變化與修 飾’皆仍屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 圖1是一流程圓，說明本發明矽晶切割液回收方法的 較佳實施例。 201217515 【主要元件符號說明】 21 稀釋步驟 22 固液分離步 23 加熱分相步• 4 cracking situation 'Therefore, the 11 ingot will use the cutting fluid with lubrication and cooling during the cutting process to reduce the mechanical stress and thermal stress damage during the cutting process; in addition, the cutting fluid has high hardness of the carbonized niobium Good grade. However, the looseness of the enthalpy and the cutting loss can further improve the stability of the dicing bar cutting process. After the cutting of the crystal rod, a large amount of cutting liquid and high hardness granules are mixed with materials such as Shi Xi and saw wire metal. The discharge of mud-like cutting waste liquid has caused the wafer manufacturing industry to face a large number of waste liquids to be disposed of, on the one hand, the manufacturing cost has increased sharply; in addition, the spirit of net energy has been replaced by solar cells as the current cleaning. The composition analysis of the waste liquid shows that the polyglycols cutting liquid contained about 3 〇 5% _ 〇 % %% while the remaining solid particles are mainly composed of carbonized granules having a particle size of 5-15 vm, and Particle size 〇丨 $ vm Cutting loss 矽, 0.5-2/zm comes from metal particles such as stainless steel saw wire. In fact, although these polyethylene glycol solutions are mixed with other solid particles and discharged in a mud state, their properties are still very stable and have a very high recovery value. With the increase in the demand for twins in recent years, the price of cutting fluid has also risen sharply in 201217515. Therefore, each Ma family is rushing to develop related processes or methods to recover the cutting waste liquid with two economic values. For example, the Chinese Patent No. CN101239246 discloses a method for recovering a twin crystal cutting liquid, which mainly uses 5~5〇% of a separating agent to be used in cutting waste liquid, and divides it into 50~95% by mechanical separation. A carbon-rich cerium slurry, and 5 to 50% of a cerium-poor cerium suspension, followed by a stabilizer added to the cerium-depleted cerium suspension, and reacted at a temperature of 7 〇 13 (rc) for a few hours, after the reaction Cooling to a temperature suitable for mechanical filtration, filtering out the solid particles of the carbon-depleted cerium suspension to obtain a recovered cutting liquid; in addition, the CN101474511 publication patent in the Chinese mainland discloses another method for recovering the crystal cutting liquid, which is mainly The solid particles are removed by multiple filtration methods by adding 3 5 to 45 times of viscosity reducing agent, which is about 3 to 4 times of the cutting waste liquid, and then the third-stage suspension obtained by filtration is vacuum distilled. Obtaining recyclable polyethylene glycol and distillate. It can be seen from the above description that most of the twin crystal cutting liquids use multiple direct filtration methods to separate solid particles and cutting liquid in the cutting waste liquid. Or by adding a stabilizer or a viscosity reducing agent, firstly, the viscosity of the cutting waste liquid is lowered, the solid particles in the cutting waste liquid are filtered out, and the cutting liquid is separated by distillation; however, since the viscosity of the cutting waste liquid is relatively high High, the direct filtration method is used to separate the solid particles in the cutting waste liquid from the cutting liquid, which not only needs to be assisted by high horsepower pumping, but also has high processing cost and time consuming, and the filter material is easily damaged; although the viscosity reducing agent can be added, Reducing the filtration time, but the subsequent cutting liquid recovered by steaming method is easy to cause oxidative deterioration of the cutting liquid because of the continuous high temperature of distillation. In addition, the use of decompression or vacuum steaming 201217515 helps to compare The viscosity-reducing agent is removed at a low temperature, but a device such as a vacuum pumping is required, and the removal speed is slow, and it is difficult to control the water content of the recovered cutting fluid, and the performance of the cutting fluid reuse is also degraded. Therefore, how to develop A simple, economical, and effective method for recovering twin crystal cutting fluids is still in the direction of continuous development of the industry. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for simply and rapidly recovering a dream crystal cutting liquid. The invention is a method for recovering a twin crystal cutting liquid, comprising a dilution step, a solid-liquid separation step, and a heating phase separation step. The dilution step is to add a cutting waste liquid containing solid particles of cerium carbide, cerium and metal, and a cutting liquid after cutting the twin crystal to a weight percentage not less than the cutting waste liquid. 〇wt% of water is diluted to form a mixed waste liquid. The solid-liquid separation step is to carry out solid-liquid separation of the mixed waste liquid, and separate solid and liquid in the mixed waste liquid to obtain an aqueous cutting liquid. The phase step is to heat the aqueous cutting liquid to a temperature not less than 45 c, so that the cutting liquid and water in the aqueous cutting liquid change solubility by temperature change k, so that the cutting liquid and the water form immiscible The cutting liquid phase and the aqueous phase are taken out, and then the cutting liquid is taken out to obtain a recovery cutting liquid, that is, the method for recovering the twin crystal cutting liquid is completed. The effect of this month is: using temperature control, so that the cutting liquid and the water phase which are mutually insoluble at the room temperature can form the liquid phase and the water phase which are mutually insoluble, so that the cutting J liquid knife can be separated, not only the method is simple 'no High energy-consuming and expensive equipment is required and a large amount of water can be removed at a constant rate. The recovered cutting liquid has a low water content of 201217515 and is stable, so the recycling efficiency is very high. The above and other technical contents, features, and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. A preferred embodiment of the method for recovering a twin crystal cutting fluid of the present invention comprises a dilution step 21, a solid-liquid separation step 22' and a heating phase separation step 23. In the dilution step 21, a cutting waste liquid is added to water having a weight percentage of not less than 10% by weight of the cutting waste liquid, and is diluted to form a mixed waste liquid. The cutting waste liquid is obtained by mixing the high-hardness carbonized shredded paper particles with the cutting liquid to form a grinding liquid liquid, and then collecting the broken crystal rods with the non-constant steel ore wire, wherein 3 liquid and solid particles are mostly liquids. The polyethylene glycol-based cutting liquid' is a solid particle which is a material such as a cerium carbide particle in a slurry and a polycrystalline cerium or a single crystal cerium particle or a saw wire metal which is lost in cutting. In the present embodiment, the solid content in the cutting waste liquid was about 700 g/L. Since the viscosity of the cutting waste liquid after mixing a large amount of solid particles is very high, it is difficult to perform subsequent solid-liquid separation operations. Therefore, the dilution step 21 is first added with water which is miscible with the cutting liquid at room temperature, and the viscosity of the cutting waste liquid is lowered to obtain a mixed waste liquid having a low viscosity. It is worth mentioning that at room temperature, when the amount of water added to the cutting waste liquid is low, hydrogen bonds are generated between the water and the main component of the cutting liquid polyethylene glycol compound, resulting in the formation of intermolecular bonds. Prolonging the molecular chain thereof will cause the viscosity of the mixed waste liquid to increase after adding a small amount of water; therefore, the amount of water added to the cutting waste liquid is not less than 1% by weight of the cutting waste liquid to obtain a mixed solution having a low viscosity of 201217515; Preferably, the amount of water added is not less than 30% by weight of the cutting waste liquid, and more preferably, the added water amount is not less than 50% by weight of the cutting waste liquid, and the viscosity of the mixed waste liquid formed is not more than the viscosity of the cutting liquid. . In the solid-liquid separation step 22, the mixed waste liquid is subjected to solid-liquid separation, and the solid content of the separated aqueous cutting liquid is controlled to be not more than 1 〇g/L. In the step 22, the mixed waste liquid with low viscosity can be subjected to solid-liquid separation through a sedimentation tank, a concentration machine, centrifugation or filtration, thereby obtaining an aqueous cutting liquid having a solid content of not more than i〇g/L. In the present embodiment, the low-viscosity mixed waste liquid is placed in a settling tank by a sedimentation method, and the solid particles are allowed to settle, thereby obtaining an aqueous liquid fraction having a low solid content. Since the mixed waste liquid is a low-viscosity liquid diluted with water, an obvious solid-liquid separation interface can be observed after standing for 10 hrs and sufficient to obtain a large amount of water having a solid content of not more than 10 g/L. The cutting liquid; the longer the standing time, the clearer the solid-liquid separation interface, the lower the solid content of the obtained aqueous cutting liquid, preferably, the solid particles are more settled after standing for 24 hr; more® After standing for 48 hr, most of the particles had settled to the bottom of the pool. It should be noted that when the solid content of the aqueous cutting liquid is greater than 1〇g/L, in the subsequent phase separation process, the solid particles may interfere with the convective disturbance effect during heating, so that it is not effective. The cutting liquid and the water form two phases which are immiscible, thereby affecting the recovery performance of the cutting liquid. The heating and separating step 23 is to heat the aqueous cutting liquid to a temperature of not less than 45 ° C, so that the cutting liquid and the water form an immiscible cutting liquid phase and an aqueous phase, and the cutting liquid and water are subjected to Separate and complete the recovery of the cutting fluid 201217515. Under normal pressure, the polyethylene glycol compound and water in the aqueous cutting liquid can be mutually dissolved to form a homogeneous liquid at room temperature due to hydrogen bonding, and when the temperature is raised, The hydrogen bond between the polyethylene glycol compound of the aqueous cutting liquid and water is destroyed, so the solubility of the polyethylene glycol compound in water is thus lowered. The present invention provides a simple and rapid method for recovering the Shi Xijing cutting liquid by the characteristic of solubility change between water and the polyethylene glycol type cutting liquid due to temperature change. By diluting the cutting waste liquid with high solid content by using water, the viscosity of the cutting waste liquid is greatly reduced by the high mutual solubility of water and the polyethylene glycol cutting liquid at normal temperature, so that the solid particles in the cutting waste liquid are effective. Removed in the solid-liquid separation process to obtain an aqueous cutting liquid having a solid content of not more than 10 μg / L; then, using temperature control, the temperature of the aqueous cutting liquid is raised to not less than 45 ^, and the water cut is destroyed by the temperature rise The solubility between the polyethylene glycol compound in the liquid and the water, and the solubility of the polyethylene glycol in water is lowered, and phase separation occurs, forming two phases which are immiscible (cutting liquid phase and water phase), so The energy-consuming unit that vaporizes water is used, and the cutting liquid whose main component is polyethylene glycol is recovered without using an expensive air suction device. Preferably, the heating phase separation step 23 is performed under the condition that the temperature is not less than 5 〇 <t; more preferably, the heating phase separation step 23 is performed at a temperature of 5 〇 70 70 ° C. . The water content of the recovered cutting liquid recovered by the preferred embodiment of the present invention (moistration titrator, Metr〇hm 87〇F Titrino plus) and viscosity (viscosity meter, Br〇〇kfieid LVDV-E, 25. , the moisture content is obtained at 〇2_2wt%, and its viscosity at 25 is fluctuated between about 1-4% compared with the original 201217515 starting cutting liquid. In summary, the present invention is made of water and polyethylene. Solubility characteristics of alcohol cutting fluid at different temperatures, using water as a diluent, by the mutual solubility of water and polyethylene glycol cutting solution at room temperature, greatly reducing the viscosity of the cutting waste liquid, therefore, can be efficiently The solid particles in the cutting waste liquid are removed; the temperature control is used to destroy the gas bond between the polyethylene glycol cutting liquid and the water, and the solubility of the cutting liquid in the water is decreased, and phase separation occurs, thereby forming two immiscible gases. Phase, the polyethylene glycol cutting fluid can be recycled and reused. Not only the method is simple and does not require an air pumping device, or high energy-consuming and expensive equipment such as evaporation and steaming, which can remove a large amount of water quickly. The recovered cutting fluid has a low water volume and The above is the object of the present invention, and the above is only the preferred embodiment and the specific examples of the present invention. The simple equivalent changes and modifications made by the scope and the description of the invention are still within the scope of the present invention. [Simplified illustration of the drawings] Fig. 1 is a flow circle illustrating the recovery method of the twin crystal cutting liquid of the present invention. Good example. 201217515 [Main component symbol description] 21 dilution step 22 solid-liquid separation step 23 heating phase separation step