CN103288086B - Recovery method of silicon carbide, silicon powder and polyethylene glycol from cutting fluid of silicon chips - Google Patents
Recovery method of silicon carbide, silicon powder and polyethylene glycol from cutting fluid of silicon chips Download PDFInfo
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Abstract
The invention discloses a recovery method of silicon carbide, silicon powder and polyethylene glycol from cutting fluid of silicon chips. The recovery method comprises the following steps: step 1, stirring and filtering the cutting fluid to separate the cutting fluid into solid compounds and liquid compounds; step 2, adding water into the solid compounds, and then stirring uniformly and filtering to get liquid and solid; step 3, precipitating the liquid of step 2 to get precipitates, washing the precipitates by water and then by acid, drying, so as to obtain the silicon powder; step 4, separating the solid of step 2 into solid-phase material and liquid-phase material, rinsing the solid-phase material, washing by alkali and then by acid, drying, screening, so as to obtain the silicon carbide finished product; step 5, separating the liquid of step 2 into solid-phase material and liquid-phase material, adding decolorising agents and filter aids into the liquid-phase material, subjecting the liquid-phase material to ion exchange treatment, distilling, so as to obtain the polyethylene glycol. The method is easy to operate. Recovering processes of the method is clean and safe, and of no pollution to the environment. Recovery rates of the silicon carbide, the polyethylene glycol and the silicon powder can reach 80% or more, 90% or more and 75% or more respectively.
Description
Technical field
The present invention relates to a kind of recovery method, particularly a kind of method extracting silicon carbide, silicon powder and polyoxyethylene glycol from silicon wafer cutting fluid.
Background technology
Silicon chip is semi-conductor, is the base mateiral of sun power, liquid-crystal display.Along with the development of sun power, the use of silicon chip gets more and more.Because silicon chip belongs to hard material, its cutting technique occupies very important position in complete processing.Traditional silicon chip cutting adopts the mode of steel disc cutting, and this cutting mode exists that joint-cutting is wider, volume recovery is low, surface figure accuracy is poor and the defects such as surface damage layer depth.In order to solve the problem, recently, there is Linear cut, by the mortar of line of cut supply with abrasive material, the cutting of silicon chip is realized by the abrasive wear principle between abrasive material, line of cut and silicon crystal, which can realize the cutting of multi-disc silicon chip, cutting efficiency is high, and silicon chip surface quality is good, but can produce a large amount of mortar waste materials.Because main component in mortar is polyoxyethylene glycol and silicon carbide, therefore, in mortar waste material, also content has a large amount of polyoxyethylene glycol and silicon carbide, meanwhile, also has a small amount of metallic iron and silicon bits.In order to recycle, can reclaim the polyoxyethylene glycol in mortar, silicon carbide and silicon material.
Chinese patent literature, the patent No. 201010528153.5, discloses a kind of method reclaiming silicon carbide and polyoxyethylene glycol cutting fluid from silicon chip dicing waste mortar, comprises the steps:
A, by mortar after stirring under normal temperature, carry out solid-liquid separation, obtain lower liquid stream and upper liquid stream;
B, lower liquid flow to into band filter, obtain the silicon carbide through cleaning, use alkali lye rinsing, after squeezing into separating centrifuge, then after band filter cleaning, use oxalic acid rinsing, then squeeze into tertiary effluent power cyclone separator, the silicon carbide obtained;
C, lower liquid flow to into the 3rd band filter, and cleaned silicon carbide enters dryer through travelling belt, and dried silicon carbide removes large granular impurity can pack through air classification classification, Vibration Screen;
The liquid portion that D, mortar obtain after being separated, carries out solid-liquid separation, adds discoloring agent and flocculating aids in liquid, enter pressure filter, isolated liquid, after deep bed filter, enters ion exchange system, slough moisture through evaporation unit again, namely obtain polyoxyethylene glycol.
Though the recyclable silicon carbide of the method and polyoxyethylene glycol, the rate of recovery of silicon carbide and polyoxyethylene glycol is lower and the purity of silicon carbide is also lower.
Chinese patent literature, the patent No. 2009102330039, discloses a kind of method extracting silicon, silicon carbide and polyoxyethylene glycol from silicon chip cutting mortar, and mortar, after stirring under normal temperature, obtains efflux of solids and liquid stream by physical sepn.Efflux of solids enters settling separation device, after reaction, obtains silicon liquid stream and silicon carbide liquid stream.Silicon liquid flows through mechanical separation and obtains solid silicon and liquid.Silicon carbide liquid flows through mechanical separation, then through a rinsing, dries, packaging.The solid silicon reclaimed is the basic raw material of silicon chip, and the silicon carbide of recovery is the auxiliary material of silicon chip cutting.Liquid flow section, adds discoloring agent and flocculating aids, enters mechanical separation, adds ion adsorbent and flocculating aids in isolated liquid, carries out mechanical separation, after membrane filtration, sloughs moisture, namely obtains polyoxyethylene glycol.The present invention can avoid the generation of polluting, and accomplish the close friendization to environment completely, but the rate of recovery of silicon carbide and polyoxyethylene glycol is lower, only has the rate of recovery of 50%, and the purity of silicon carbide is also lower, silicon-carbide particle granularity is uneven in addition, particle size distribution range D
50value becomes large, if directly again for silicon chip cutting, will affect the quality in silicon chip cutting face, and the water yield used in recovery is large, and sewage effluent amount is more.
Summary of the invention
Technical problem to be solved by this invention is to provide the recovery method of silicon carbide, silicon powder and polyoxyethylene glycol in a kind of silicon wafer cutting fluid, the method is easy to operate, removal process, technique is clean, safety, to environment without dirt, in addition, the silicon carbide reclaimed and polyoxyethylene glycol quality product can reach the standard of product innovation completely, the rate of recovery is high: the rate of recovery of silicon carbide can reach more than 80%, and the rate of recovery of polyoxyethylene glycol can reach more than 90%, and the rate of recovery of silicon can reach more than 75%.
From silicon chip cutting mortar, extract a method for silicon, silicon carbide and polyoxyethylene glycol, comprise following step:
A, cutting fluid to be stirred, through number of looking over so as to check for after 10-100 object screen filtration, then isolate solid ingredient and liquid ingredient through whizzer;
Add water in B, solid ingredient to stir formation solidliquid mixture, water: solid composition=1-5: 1 (calculating with mass parts); By pressure filter by the solid in fixing mixture and liquid separation, the water content of solid is made to reach 3-5%;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
E, extraction silicon carbide:
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, solid part is entered vacuum band-type filter machine and carry out filtering and rinsing, the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process;
E2, silicon carbide work in-process to be dewatered, obtain the silicon carbide filter body that water content is 5-20% (by mass percentage), dry further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, obtain finished silicon carbide product;
F, extraction polyoxyethylene glycol,
F1, by steps A liquid ingredient be separated, obtain solid and liquid, add 0.1-2% discoloring agent and 0.1-0.5% flocculating aids, continuously stirring under 40-80 degree in liquid, churning time is 0.2-2 hour, and stirring velocity is that 60-120 turns/min;
F2, the liquid obtained through step F 1 to be filtered;
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 0-40 degree;
F4, to distill after the liquid filtering after ion-exchange, obtain the polyoxyethylene glycol distillation body that water content is less than 0.5%;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product.
The above-mentioned method extracting silicon, silicon carbide and polyoxyethylene glycol from silicon chip cutting mortar, wherein, be separated by the method for precipitation in step C and obtain silicon carbide material and silicon feed liquid, precipitation comprises the steps:
C1, step B filtered the solid that obtains and water stirs, water: solid=2-10: 1 is by mass parts; Under normal temperature state, leave standstill 1-4 hour, heavy precipitation be silicon carbide material, lightweight suspension be silicon feed liquid, collect respectively;
C2, repeated washing is carried out 2-5 time to silicon carbide material, and collect and clean the silicon feed liquid and silicon carbide material that obtain at every turn.
The above-mentioned method extracting silicon, silicon carbide and polyoxyethylene glycol from silicon chip cutting mortar, wherein, step D comprises the steps:
D1, pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=1-3: 1 (by mass);
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 0.5-2 hour, form silicon solution, in silicon solution, concentration of hydrochloric acid is 1-10% (by mass percentage densitometer);
Filter after D3, pickling and clean the silicon powder filter body obtained, silicon powder is filtered body and dry at 100-150 degree, continuous discharge during oven dry, discharging speed is 1.5hr.
The above-mentioned method extracting silicon, silicon carbide and polyoxyethylene glycol from silicon chip cutting mortar, wherein, pre-treatment is carried out to silicon feed liquid and refers to silicon feed liquid by stating step C, discharge supernatant liquid after the upper water solution of silicon feed liquid is limpid, retain 1-3 times that surplus water is precipitated solid amount, under normal temperature, leave standstill 4-12 hour.
The above-mentioned method extracting silicon, silicon carbide and polyoxyethylene glycol from silicon chip cutting mortar, wherein, adopt mass percent concentration to be that the alkaline solution of 1-10% carries out continuously stirring cleaning in described step e 1 during alkali cleaning, churning time is 0.5-4 hour, and stirring velocity is 60-120r/min; Adopt mass percent concentration to be that the acid solution of 1-10% carries out continuously stirring cleaning during pickling, churning time is 0.5-4 hour, and stirring velocity is 60-120r/min.
The above-mentioned method extracting silicon, silicon carbide and polyoxyethylene glycol from silicon chip cutting mortar, wherein, in described step F 5, cooling adopts chilling technique to cool, and namely in 1-5 minute, is cooled to 40 degree from 40-130 degree.
Beneficial effect of the present invention is as follows:
1. production technique comprehensively, system, complete, reclaimed most valuable composition in cutting fluid, at utmost realized resource reutilization
2. stable processing technique, maturation, the silicon carbide reclaimed and polyoxyethylene glycol quality product can reach the standard of product innovation completely, the rate of recovery is high: the rate of recovery of silicon carbide can reach more than 80%, and the rate of recovery of polyoxyethylene glycol can reach more than 90%, and the rate of recovery of silicon can reach more than 75%
3. process design is advanced, can realize increasingly automated continuous seepage, enhance productivity
4. whole removal process is pure physiochemical mutagens process, and technique is clean, safety, environmentally safe
5. reclaim silicon carbide micro-powder centralized particle diameter, foreign matter content is few, and purity is high, moisture and polyoxyethylene glycol residual quantity low
6. the polyoxyethylene glycol reclaimed is not containing any other chemical composition, and moisture content is low.
Accompanying drawing explanation
Fig. 1 is process flow sheet of the present invention.
Embodiment
Below in conjunction with specific embodiment, the invention will be further described.
From silicon chip cutting mortar, extract a method for silicon, silicon carbide and polyoxyethylene glycol, comprise the steps:
A, cutting fluid to be stirred, be that 800-1500r/min carries out continuously stirring with stirring velocity under normal temperature, churning time 60-120min, again after number of looking over so as to check is 10-100 object screen filtration, isolate solid ingredient and liquid ingredient through whizzer again, the speed at ambient pressure with 2500-3500r/min during separation is separated; By carrying out sub-sieve to used cutting liquid, can first be carried out screening out process by the large particle in mortar, when can prevent subsequent disposal, solid becomes cake not easily to pulverize, improve subsequent disposal efficiency, alleviate subsequent disposal workload, reduce the amount of disposing waste liquid, alleviate environmental pollution;
Add water in B, solid ingredient to stir and form fixing mixture, water: solid composition=1-5: 1 (calculating with mass parts); By pressure filter by the solid in fixing mixture and liquid separation, pressure is 3.5-4.5bar, and the time is 1-3hr, makes the water content of solid reach 3-5%; For subsequent use in liquid collecting to the liquid components in steps A; Again reclaim for polyoxyethylene glycol remaining in solid ingredient, compared to existing technology, the polyoxyethylene glycol rate of recovery improves, and can reach more than 90%; In solid phase separating treatment, water consumption is few, is only 30% of prior art water consumption, can reduce sewage output, alleviate environmental pollution;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid; Separation obtains silicon carbide material and silicon feed liquid is separated by sedimentation device, is also separated by other modes;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
E, extraction silicon carbide: during silicon carbide reclaims, the technology that the present invention adopts multistage swirling flow to be separated, Automatic sieve selects high-quality, highly purified silicon carbide, being evenly distributed of particle diameter is concentrated, the silicon-carbide particle reclaimed meets the requirement of new mortar completely, the purity of silicon carbide reaches more than 99.5%, can unlimitedly recycle
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, solid part enters vacuum band-type filter machine to carry out filtering and rinsing, and the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process; Mass percent concentration is adopted to be that the alkaline solution (alkaline solution is sodium hydroxide) of 1-10% carries out stirring and washing in described step e 1 during alkali cleaning, churning time is 0.5-4 hour, stirring velocity is that 60-120 turns/min, mass percent concentration is adopted to be that (acid solution can be oxalic acid for the acid solution of 1-10% during pickling, also can be hydrochloric acid) carry out stirring and washing, continuously stirring is 0.5-4 hour, stirring velocity is 60-120r/min, make silicon carbide material and acid solution hybrid reaction evenly, prevent silicon carbide material from precipitating; In order to decreasing pollution, acid solution is preferably weak acid, can adopt oxalic acid.
E2, silicon carbide work in-process to be dewatered, obtain the silicon carbide filter body that water content is 5-20% (by mass percentage), dry further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, obtain finished silicon carbide product;
F, extraction polyoxyethylene glycol, during polyoxyethylene glycol reclaims, any pickling process is not carried out to liquid phase component, do not add any pH adjusting agent, guarantee the original Wuli-Shili-Renli system approach of polyoxyethylene glycol, adopt secondary filter technology in reclaiming, can environmental pollution be reduced, the whole knot of recovery workshop environment, clean can be kept.
F1, steps A liquid ingredient to be separated, obtain solid and liquid, 0.1-2% discoloring agent is added (as gac in liquid, absorption bamboo property fiber) and 0.1-0.5% flocculating aids (as diatomite, perlite), stir under 40-80 degree, the continuously stirring time is 0.2-2 hour, and stirring velocity is 60-120r/min;
F2, the liquid obtained through step F 1 to be filtered; Filtering requirement filtrate is as clear as crystal, can not contain any solid impurity in filtrate, and adopt full-automatic accurate metre filter, filtering accuracy can reach 0.1 micron
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 0-40 degree; Ion-exchange can make the various metal that originally contained in liquid and (nonmetallic ion, as calcium ion, magnesium ion, iron ion, chlorion, sulfate ion etc., absorbed by ion exchange resin and remove these ions, improve the purity of polyoxyethylene glycol, these ion-solubility in water, if do not removed, when in polyoxyethylene glycol water distillation time, these ions can be separated out from solution, cause equipment scaling.Ion exchange resin after using uses hydrochloric acid and sodium hydroxide regeneration, can Reusability;
F4, the liquid after ion-exchange to be distilled, obtain the polyoxyethylene glycol that water content is less than 0.5%.Distillation parameter: vaporization temperature scope 50-130 degree, vacuum tightness-0.03 ~-0.1MPa;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product.In described step F 5, cooling adopts chilling technique to cool, and namely in 1-5 minute, is cooled to 40 degree from 40-130 degree.The colourity of polyoxyethylene glycol, viscosity, pH and chemical stability can be kept after being chilled to normal temperature, keep high temperature can cause the chemical stability of the change of above product performance and product for a long time.Heat exchange can use various interchanger to carry out, and uses water coolant and material-heat-exchanging to cool, generally uses plate-type heat exchanger.Processing parameter: as long as the object being cooled to 40 degree can be reached in 1-5 minute.
Be separated by the method for precipitation in step C and obtain silicon carbide material and silicon feed liquid, precipitation comprises the steps:
C1, step B filtered the solid that obtains and water stirs, water: solid=2-10: 1 is by mass parts; Under normal temperature state, leave standstill 1-4 hour, heavy precipitation be silicon carbide material, lightweight suspension be silicon liquid material, collect respectively;
C2, repeated washing is carried out 2-5 time to silicon carbide material, and collect and clean the silicon liquid material and silicon carbide material that obtain at every turn; The silica flour purity that precipitate and separate obtains is high, settling separation device is the process of dynamic separation, the settling velocity of silicon and silicon carbide is close, dynamic separation is complete not, the silica flour purity obtained is generally about 80%, and precipitate and separate is static separation process, by adjustment sedimentation time, silicon is comparatively complete with being separated of silicon carbide, and the silica flour purity therefore obtained is higher.
Step D extracts silicon powder and comprises the steps:
D1: silicon material first precipitates, part of draining water object is concentrated solution, reduces the amount of solution, can reduce later stage hydrochloric acid consumption.D2: adding hydrochloric acid object is remove the insoluble impurities in silicon, improves the purity of silicon.D3: cleaning washes away the hydrochloric acid remained in silicon, obtains product after oven dry.
D1, precipitation pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=2: 1 (by mass);
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 0.5-2 hour, form silicon solution, in silicon solution, concentration of hydrochloric acid is that the amount that 1-10% adds hydrochloric acid adds according to the ratio of silicon feed liquid in concentration of hydrochloric acid 1-10%, if any the silicon feed liquid 1000g adding hydrochloric acid, concentration of hydrochloric acid is 1%, then wherein containing 10g hydrochloric acid, concentration of hydrochloric acid is 10%, then wherein containing 100g hydrochloric acid.
Filter after D3, pickling and clean the silicon material obtained, by silicon material in the discharging of 100-150 degree continuous drying, obtaining silicon powder, discharging 1.5 hours.
Embodiment one
Extract a method for silicon, silicon carbide and polyoxyethylene glycol in silicon chip cutting mortar, comprise the steps:
A, cutting fluid to be stirred, be that 800r/min carries out continuously stirring with stirring velocity under normal temperature, churning time churning time 60 minutes, again after 10 object screen filtrations, enter supercentrifuge and isolate solid ingredient 579g and liquid ingredient 420g, isolate solid ingredient and liquid ingredient through whizzer again, the speed at ambient pressure with 2600r/min during separation is separated; Cutting fluid: carbonization model silicon 1500 order, poly-second two model alcohol 200, silicon carbide D50 index 8.01 microns.Wherein each component content: silicon carbide 44%, silicon 6%, iron and its oxi 5%, polyoxyethylene glycol 42%, water 2%, other impurity 1%;
Add water in B, solid ingredient to stir and form fixing mixture, water: solid composition=2: 1 (calculating with mass parts); By pressure filter by the solid in fixing mixture and liquid separation, pressure is 3.6bar, and the time is 2hr, makes the water content of solid reach 4.5%; For subsequent use in liquid collecting to the liquid components in steps A;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid;
C1, step B filtered the solid that obtains and water stirs, water: solid=8: 1 by mass parts; Under normal temperature state, leave standstill 4 hours, heavy precipitation be silicon carbide material, lightweight suspension be silicon liquid material, collect respectively;
C2, repeated washing is carried out 2 times to silicon carbide material, and collect and clean the silicon liquid material and silicon carbide material that obtain at every turn;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
D1, precipitation pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=2: 1 (by mass);
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 2 hours, form silicon solution, in silicon solution, concentration of hydrochloric acid is 1%;
Filter after D3, pickling and clean the silicon material obtained, by silicon material 120 degree of continuous drying dischargings, obtaining silicon powder, discharging 1.5hr
E, extraction silicon carbide
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, the operating pressure 3.5bar of hydraulic vortex flow devices, solid part enters vacuum band-type filter machine to carry out filtering and rinsing, and the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process; In described step e 1 during alkali cleaning adopt mass percent concentration be 1% sodium hydroxide carry out stirring and washing, churning time is 4 hours, stirring velocity is 100r/min, mass percent concentration is adopted to be that stirring and washing is carried out in 1% acid during pickling, continuously stirring is 4 hours, stirring velocity is 100r/min, makes carbonized stock and acid solution hybrid reaction evenly, prevents carbonized stock from precipitating; In order to decreasing pollution, acid solution is preferably weak acid, can adopt oxalic acid.
E2, silicon carbide work in-process to be dewatered, obtain the silicon carbide filter body that water content is 8% (by mass percentage), dry further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, finished product after silicon carbide;
F, extraction polyoxyethylene glycol,
F1, steps A liquid ingredient to be separated, obtain solid and liquid, add the diatomite perlite of mass percent 0.5% gac and mass percent 0.5% in liquid, stir under 40 degree, the continuously stirring time is 1.5 hours, and stirring velocity is 60r/min;
F2, the liquid obtained through step F 1 to be filtered;
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 0 degree;
F4, to distill after the liquid filtering after ion-exchange, obtain the polyoxyethylene glycol that water content is less than 0.5%.Distillation parameter: vaporization temperature scope 120 degree, vacuum tightness-0.09MPa;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product.In described step F 5, cooling adopts chilling technique to cool, and namely in 5 minutes, is cooled to 40 degree from 120 degree.
Performance index:
Embodiment two
From silicon chip cutting mortar, extract a method for silicon, silicon carbide and polyoxyethylene glycol, comprise the steps:
A, cutting fluid to be stirred, be that 1200r/min carries out continuously stirring with stirring velocity under normal temperature, churning time 80min, through number of looking over so as to check be after 50 object screen filtrations again, enter supercentrifuge and isolate solid ingredient (574g) and liquid ingredient (426g), isolate solid ingredient and liquid ingredient through whizzer again, the speed at ambient pressure with 3400r/min during separation is separated; Cutting fluid: carbonization model silicon 1500 order, poly-second two model alcohol 200, silicon carbide D50 index 8.01 microns.Wherein each component content: silicon carbide 44%, silicon 6%, iron and its oxi 5%, polyoxyethylene glycol 42%, water 2%, other impurity 1%;
Add water in B, solid ingredient to stir and form fixing mixture, water: solid composition=5: 1 (calculating with mass parts); By pressure filter by the solid in fixing mixture and liquid separation, pressure is 4.2bar, and the time is 3hr, makes the water content of solid reach 3.3%; For subsequent use in liquid collecting to the liquid components in steps A;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid;
C1, step B filtered the solid that obtains and water stirs, water: solid=2: 1 by mass parts;
Under normal temperature state, leave standstill 1 hour, heavy precipitation be silicon carbide material, lightweight suspension be silicon liquid material, collect respectively;
C2, repeated washing is carried out 5 times to silicon carbide material, and collect and clean the silicon liquid material and silicon carbide material that obtain at every turn;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
D1, precipitation pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=2: 1 (by mass);
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 1 hour, form silicon solution, in silicon solution, concentration of hydrochloric acid is 5%;
Filter after D3, pickling and clean the silicon material obtained, by silicon material 140 degree of continuous drying dischargings, obtaining silicon powder, discharging 1.5hr
E, extraction silicon carbide
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, hydraulic vortex flow devices operating pressure 3.9bar, solid part enters vacuum band-type filter machine to carry out filtering and rinsing, and the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process; In described step e 1 during alkali cleaning adopt mass percent concentration be 5% sodium hydroxide carry out stirring and washing, churning time is 1 hour, stirring velocity is 60r/min, mass percent concentration is adopted to be that 5% oxalic acid carries out stirring and washing during pickling, continuously stirring is 1 hour, stirring velocity is 60r/min, makes carbonized stock and acid solution hybrid reaction evenly, prevents carbonized stock from precipitating; In order to decreasing pollution, acid solution is preferably weak acid, can adopt oxalic acid.
E2, silicon carbide work in-process to be dewatered, obtain the silicon carbide filter body that water content is 12.4% (by mass percentage), dry further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, finished product after silicon carbide;
F, extraction polyoxyethylene glycol,
F1, by steps A liquid ingredient be separated, obtain solid and liquid, add the perlite of 1.5% absorption bamboo property fiber and 0.2% in liquid, stir under 75 degree, the continuously stirring time is 0.5 hour, and stirring velocity is 80r/min;
F2, the liquid obtained through step F 1 to be filtered;
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 35 degree;
F4, to distill after the liquid filtering after ion-exchange, obtain the polyoxyethylene glycol that water content is less than 0.5%.Distillation parameter: vaporization temperature scope 90 degree, vacuum tightness-0.098MPa;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product.In described step F 5, cooling adopts chilling technique to cool, and namely in 2 minutes, is cooled to 40 degree from 90 degree.
Performance index:
Embodiment three
From silicon chip cutting mortar, extract a method for silicon, silicon carbide and polyoxyethylene glycol, comprise the steps:
A, cutting fluid to be stirred, be that 1500r/min carries out continuously stirring with stirring velocity under normal temperature, churning time 60min, again after 100 object screen filtrations, enter supercentrifuge and isolate solid ingredient 585g and liquid ingredient 415g, isolate solid ingredient and liquid ingredient through whizzer again, the speed at ambient pressure with 3100r/min during separation is separated; Cutting fluid: carbonization model silicon 1500 order, poly-second two model alcohol 200, silicon carbide D50 index 8.01 microns.Wherein each component content: silicon carbide 44%, silicon 6%, iron and its oxi 5%, polyoxyethylene glycol 42%, water 2%, other impurity 1%;
Add water in B, solid ingredient to stir and form fixing mixture, water: solid composition=3: 1 (calculating with mass parts); By pressure filter by the solid in fixing mixture and liquid separation, pressure is 4.0bar, and the time is 2.5hr, makes the water content of solid reach 4.1%; For subsequent use in liquid collecting to the liquid components in steps A;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid;
C1, step B filtered the solid that obtains and water stirs, water: solid=5: 1 by mass parts; Under normal temperature state, leave standstill 3 hours, heavy precipitation be silicon carbide material, lightweight suspension be silicon liquid material, collect respectively;
C2, repeated washing is carried out 3 times to silicon carbide material, and collect and clean the silicon liquid material and silicon carbide material that obtain at every turn;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
D1, precipitation pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=2: 1 (by mass);
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 1.5 hours, form silicon solution, in silicon solution, concentration of hydrochloric acid is 3%;
Filter after D3, pickling and clean the silicon material obtained, by silicon material 125 degree of continuous drying dischargings, obtaining silicon powder, discharging 1.5hr
E, extraction silicon carbide
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, the operating pressure 3.7bar of hydraulic vortex flow devices, solid part is carried out vacuum band-type filter machine to carry out filtering and rinsing, the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process; In described step e 1 during alkali cleaning adopt mass percent concentration be 3% sodium hydroxide carry out stirring and washing, churning time is 2 hours, stirring velocity is 80r/min, mass percent concentration is adopted to be that 3% oxalic acid carries out stirring and washing during pickling, continuously stirring is 2 hours, stirring velocity is 80r/min, makes carbonized stock and acid solution hybrid reaction evenly, prevents carbonized stock from precipitating; In order to decreasing pollution, acid solution is preferably weak acid, can adopt oxalic acid.
E2, silicon carbide work in-process to be dewatered, obtain the silicon carbide filter body that water content is 10.3% (by mass percentage), dry further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, finished product after silicon carbide;
F, extraction polyoxyethylene glycol,
F1, by steps A liquid ingredient be separated, obtain solid and liquid, in liquid, add the perlite of 0.8% gac and 0.3%), stir under 55 degree, the continuously stirring time is 1 hour, and stirring velocity is 80r/min;
F2, the liquid obtained through step F 1 to be filtered;
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 30 degree;
F4, to distill after the liquid filtering after ion-exchange, obtain the polyoxyethylene glycol that water content is less than 0.5%.Distillation parameter: vaporization temperature scope 110 degree, vacuum tightness-0.096MPa;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product.In described step F 5, cooling adopts chilling technique to cool, and namely in 4 minutes, is cooled to 40 degree from 110 degree.
Performance index:
The present invention is not limited to above-described embodiment; every on the basis of technical scheme disclosed by the invention; those skilled in the art is according to disclosed technology contents; do not need performing creative labour just can make some to some technical characteristics wherein to replace and distortion, these are replaced and are out of shape all in the scope of protection of the invention.
Claims (2)
1. the recovery method of silicon carbide, silicon powder and polyoxyethylene glycol in silicon chip cutting mortar, is characterized in that, comprise the steps:
A, cutting fluid to be stirred, be that 800r/min carries out continuously stirring with stirring velocity under normal temperature, churning time churning time 60 minutes, again after 10 object screen filtrations, enter supercentrifuge and isolate solid ingredient 579g and liquid ingredient 420g, isolate solid ingredient and liquid ingredient through whizzer again, the speed at ambient pressure with 2600r/min during separation is separated;
Add water in B, solid ingredient to stir and form fixing mixture, water: solid composition=2:1 calculates with mass parts; By pressure filter by the solid in fixing mixture and liquid separation, pressure is 3.6bar, and the time is 2hr, makes the water content of solid reach 4.5%; For subsequent use in liquid collecting to the liquid components in steps A;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid;
C1, step B filtered the solid that obtains and water stirs, water: solid=8:1 is by mass parts; Under normal temperature state, leave standstill 4 hours, heavy precipitation be silicon carbide material, lightweight suspension be silicon liquid material, collect respectively;
C2, repeated washing is carried out 2 times to silicon carbide material, and collect and clean the silicon liquid material and silicon carbide material that obtain at every turn;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
D1, precipitation pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=2:1, by mass;
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 2 hours, form silicon solution, in silicon solution, concentration of hydrochloric acid is 1%;
Filter after D3, pickling and clean the silicon material obtained, by silicon material 120 degree of continuous drying dischargings, obtaining silicon powder, discharging 1.5hr
E, extraction silicon carbide
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, the operating pressure 3.5bar of hydraulic vortex flow devices, solid part enters vacuum band-type filter machine to carry out filtering and rinsing, and the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process; In described step e 1 during alkali cleaning adopt mass percent concentration be 1% sodium hydroxide carry out stirring and washing, churning time is 4 hours, stirring velocity is 100r/min, mass percent concentration is adopted to be that stirring and washing is carried out in 1% acid during pickling, continuously stirring is 4 hours, stirring velocity is 100r/min, makes carbonized stock and acid solution hybrid reaction evenly, prevents carbonized stock from precipitating;
E2, dewatered by silicon carbide work in-process, obtaining water content is 8%, and silicon carbide filter body by mass percentage, dries further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, and finished product after silicon carbide;
F, extraction polyoxyethylene glycol,
F1, by steps A liquid ingredient be separated, obtain solid and liquid, add the diatomite perlite of mass percent 0.5% gac and mass percent 0.5%, stir under 40 degree in liquid, the continuously stirring time is 1.5 hours, and stirring velocity is 60r/min;
F2, the liquid obtained through step F 1 to be filtered;
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 0 degree;
F4, to distill after the liquid filtering after ion-exchange, obtain the polyoxyethylene glycol that water content is less than 0.5%; Distillation parameter: vaporization temperature scope 120 degree, vacuum tightness-0.09MPa;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product; In described step F 5, cooling adopts chilling technique to cool, and namely in 5 minutes, is cooled to 40 degree from 120 degree.
2. the recovery method of silicon carbide, silicon powder and polyoxyethylene glycol in silicon chip cutting mortar, is characterized in that, comprise the steps:
A, cutting fluid to be stirred, be that 1500r/min carries out continuously stirring with stirring velocity under normal temperature, churning time 60min, again after 100 object screen filtrations, enter supercentrifuge and isolate solid ingredient 585g and liquid ingredient 415g, isolate solid ingredient and liquid ingredient through whizzer again, the speed at ambient pressure with 3100r/min during separation is separated;
Add water in B, solid ingredient to stir and form fixing mixture, water: solid composition=3:1, calculates with mass parts; By pressure filter by the solid in fixing mixture and liquid separation, pressure is 4.0bar, and the time is 2.5hr, makes the water content of solid reach 4.1%; For subsequent use in liquid collecting to the liquid components in steps A;
C, step B filtered the solid obtained and carry out separation and obtain silicon carbide material and silicon feed liquid;
C1, step B filtered the solid that obtains and water stirs, water: solid=5:1 is by mass parts; Under normal temperature state, leave standstill 3 hours, heavy precipitation be silicon carbide material, lightweight suspension be silicon liquid material, collect respectively;
C2, repeated washing is carried out 3 times to silicon carbide material, and collect and clean the silicon liquid material and silicon carbide material that obtain at every turn;
D, extract silicon powder, carry out precipitation obtain silicon material by collecting the silicon feed liquid obtained in step C, then pickling, filtration are carried out to silicon material, the solid matter after filtering is dried, obtains silicon powder;
D1, precipitation pre-treatment is carried out to silicon feed liquid, make the liquid phase in silicon feed liquid: solid phase=2:1, by mass;
D2, in pretreated silicon feed liquid, add hydrochloric acid, and stir 1.5 hours, form silicon solution, in silicon solution, concentration of hydrochloric acid is 3%;
Filter after D3, pickling and clean the silicon material obtained, by silicon material 125 degree of continuous drying dischargings, obtaining silicon powder, discharging 1.5hr;
E, extraction silicon carbide;
E1, the silicon carbide material obtained in step C is entered hydraulic vortex flow devices, carry out solid-liquid separation, the operating pressure 3.7bar of hydraulic vortex flow devices, solid part is carried out vacuum band-type filter machine to carry out filtering and rinsing, the solid part after rinsing carries out alkali cleaning, pickling, refining purification obtain silicon carbide work in-process; In described step e 1 during alkali cleaning adopt mass percent concentration be 3% sodium hydroxide carry out stirring and washing, churning time is 2 hours, stirring velocity is 80r/min, mass percent concentration is adopted to be that 3% oxalic acid carries out stirring and washing during pickling, continuously stirring is 2 hours, stirring velocity is 80r/min, makes carbonized stock and acid solution hybrid reaction evenly, prevents carbonized stock from precipitating;
E2, dewatered by silicon carbide work in-process, obtaining water content is 10.3%, by mass percentage, silicon carbide filter body, dry further, make silicon carbide water content be less than 0.1%, after screening out large particulate matter, finished product after silicon carbide;
F, extraction polyoxyethylene glycol,
F1, by steps A liquid ingredient be separated, obtain solid and liquid, add the perlite of 0.8% gac and 0.3% in liquid, stir under 55 degree, the continuously stirring time is 1 hour, and stirring velocity is 80r/min;
F2, the liquid obtained through step F 1 to be filtered;
F3, the liquid after filtering through step F 2 is entered ion exchange system, feeding temperature controls at 30 degree;
F4, to distill after the liquid filtering after ion-exchange, obtain the polyoxyethylene glycol that water content is less than 0.5%; Distillation parameter: vaporization temperature scope 110 degree, vacuum tightness-0.096MPa;
F5, polyoxyethylene glycol distilled body cooling, form polyoxyethylene glycol product; In described step F 5, cooling adopts chilling technique to cool, and namely in 4 minutes, is cooled to 40 degree from 110 degree.
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| CN105623829A (en) * | 2015-03-11 | 2016-06-01 | 辽宁工业大学 | Method for recovering polyethylene glycol cutting fluid from waste mortar of crystal silicon wire cutting |
| CN105621414A (en) * | 2015-03-11 | 2016-06-01 | 辽宁工业大学 | Method for recovering silicon carbide from waste mortar of crystal silicon wire cutting |
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| CN107325870A (en) * | 2017-07-19 | 2017-11-07 | 常州赛蓝光伏技术有限公司 | The method for preparing cutting particle loaded fluid is reclaimed using useless silicon mud |
| CN107487773A (en) * | 2017-08-09 | 2017-12-19 | 中国恩菲工程技术有限公司 | Handle the method and system of silicon materials cutting disposed slurry |
| CN114516696A (en) * | 2022-01-17 | 2022-05-20 | 南京沿江资源生态科学研究院有限公司 | Method and equipment for recycling process waste liquid in polyether polyurethane industry |
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