CN102079520A - Recycling method of silicon carbide - Google Patents

Recycling method of silicon carbide Download PDF

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Publication number
CN102079520A
CN102079520A CN 201110021374 CN201110021374A CN102079520A CN 102079520 A CN102079520 A CN 102079520A CN 201110021374 CN201110021374 CN 201110021374 CN 201110021374 A CN201110021374 A CN 201110021374A CN 102079520 A CN102079520 A CN 102079520A
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silicon
silicon carbide
mixture
impurity
carbide
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孙玉龙
刘永浩
蔡明哲
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Hong Jing Environment Co
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Hong Jing Environment Co
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Abstract

The invention discloses a recycling method of silicon carbide for recycling silicon carbide in silicon-containing mortar, wherein the silicon-containing mortar contains silicon carbide, silicon, impurities and dispersion. The method comprises the following steps: filtering the silicon-containing mortar to remove dispersion preliminarily and obtain silicon mud; heating silicon mud to volatilize residual dispersion and obtain silicon carbide/silicon mixture without impurities; placing the silicon carbide/silicon mixture in alkaline solution to dissolve silicon in the mixture; and removing alkaline solution with the dissolved silicon to obtain the purified silicon carbide. The invention has the following advantages: 1) the deterioration of dispersion in the silicon-containing mortar can be avoided; 2) organic solvent is not used for separating silicon carbide; and 3) the high speed centrifugation method is not required for separating silicon carbide.

Description

A kind of recovery method of silicon carbide
Technical field
The invention belongs to the recovery method of a kind of recovery method, particularly a kind of silicon carbide.
Background technology
Silicon chip has been widely used in solar industry and electronic industry at present, and the making of silicon chip is normally cut acquisition to silicon crystal bar.Wherein, silicon crystal bar cutting is normally followed with parting tool and is used machining oil (polyoxyethylene glycol for example, PEG) silicon crystal bar is cut and produce slicing slurry, make the compositions such as cutting loss that include silicon carbide, silicon, machining oil and cutting tool in this slicing slurry usually.If directly slicing slurry is abandoned, not only cause environmental pollution, also will cause the waste of raw material.Therefore, existing at present relevant unit drops into the recovery correlation technique of silicon carbide and silicon in the research and development slicing slurry.
The recovery method of present known silicon carbide, normally in slicing slurry, add a large amount of sepa-ration aid (for example water or organic solvent etc.) earlier and dilute slicing slurry, with cascade filtration slicing slurry is filtered again, liquid machining oil and water are separated with solid-state silicon carbide and silicon.The solid silicon carbide and the silicon that filter the back acquisition can utilize following several mode to separate usually:
1. high temperature separates: because the fusing point of silicon carbide is 2545 ℃, the fusing point of silicon is 1412 ℃, therefore can utilize the different characteristic of the two fusing point, carries out high temperature with electric furnace and separates, and silicon carbide is separated with silicon.
Yet this method not only consumes energy greatly, and is seriously polluted, is subject to the TaiWan, China regulation limitations again, therefore more infeasible.
2. heavy-fluid is separated: it is that this silicon carbide and silicon are inserted in the organic solvent (as bromofom) of proportion between the proportion of silicon carbide and silicon that heavy-fluid is separated, carry out high speed centrifugation again, so, the silicon that proportion is lower than organic solvent will float on liquid level, to be deposited in the organic solvent and proportion is higher than the silicon carbide of organic solvent, silicon carbide is separated with silicon, and then obtain the recyclable silicon that utilizes again.
Yet this method is owing to the interpolation of organic solvent, and the toxicity of this organic solvent will cause problem of environmental pollution, and the low flashing point of this organic solvent also causes the danger in the processing procedure easily; Again and, ultracentrifugal equipment price costliness, the shortcoming that also will cause cost recovery to increase.
3. pneumatic flotation: this method is by interfacial agent being added in silicon carbide and the silicon, interfacial agent forms foam, because this interfacial agent is higher to the affinity of silicon carbide, therefore can be with silicon carbide absorption in the upper strata, and silicon will be precipitated to lower floor, so, just, silicon carbide can be separated with silicon.Yet the identical shortcoming with toxicity and low flashing point with organic solvent of this interfacial agent will cause this method to have shortcoming dangerous in environmental pollution and the processing procedure.
For these reasons, it is necessary further to improve the recovery method of above-mentioned silicon carbide.
Summary of the invention
The objective of the invention is provides a kind of recovery method of silicon carbide in order to overcome the shortcoming of prior art, to avoid the dispersion liquid in the siliceous mortar rotten; To avoid with an organic solvent separating silicon carbide; To avoid the using high speed centrifugation mode to separate silicon carbide.
The technical scheme that the present invention solves the problems of the technologies described above is as follows:
1. one of recovery method of a silicon carbide is that siliceous mortar contains silicon carbide, silicon, impurity and dispersion liquid to the recovery method of silicon carbide in the siliceous mortar; The method steps that reclaims silicon carbide wherein is as follows:
1) filter:
The siliceous mortar that will comprise silicon carbide, silicon, impurity and dispersion liquid filters, and obtains the impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture;
2) raffinate is removed:
The impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture is heated, and temperature>250 ℃ make residual dispersion liquid volatilization, obtain impure silicon carbide/silicon mixture;
3) pickling impurity removal matter:
Impure silicon carbide/silicon mixture is soaked the acidic solution that places acidic solution or include auxiliary agent, by the impurity in acid leach solution silicon carbide/silicon mixture, refilter and remove the acidic solution that is dissolved with impurity, obtain preliminary silicon carbide/silicon mixture of removing impurity;
4) stir
Silicon carbide/silicon mixture of removing impurity is added in the water medium of pH2.5~14, and leave standstill after stirring, obtain sedimentary silicon carbide/silicon mixture and be suspended with the liquid medium of silicon, after filtration sedimentary silicon carbide/silicon mixture separation is gone out, obtain the silicon carbide/silicon mixture of initial gross separation silicon;
The liquid medium that is suspended with silicon is filtered, the filtering liquid medium obtains silicon, silicon is added in the acidic solution, with the impurity in the dissolves silicon, after filtering is dissolved with the acidic solution of impurity again, obtain the silicon of purifying, or carry out the electromagnetism high intensity magnetic separation and be coated with the silicon of magnetic-particle with removal, this acidic solution of filtering is to obtain the silicon behind the purifying again.
5) silicon dissolving:
Silicon carbide/silicon mixture of removing impurity is placed basic solution, make basic solution dissolve silicon in this silicon carbide/silicon mixture, obtain to be dissolved with the basic solution and the silicon carbide precipitation of silicon;
6) alkali lye is removed:
Remove the basic solution that this is dissolved with silicon,, obtain the silicon carbide of purifying with flushing with clean water silicon carbide precipitation.
2. two of the recovery method of a silicon carbide, be that siliceous mortar contains silicon carbide, silicon, impurity and dispersion liquid to the recovery method of silicon carbide in the siliceous mortar; The method steps that reclaims silicon carbide wherein is as follows:
1) filter:
The siliceous mortar that will comprise silicon carbide, silicon, impurity and dispersion liquid filters, and obtains the impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture;
2) raffinate is removed:
The impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture is heated, and temperature>250 ℃ make residual dispersion liquid volatilization, obtain impure silicon carbide/silicon mixture;
3) pickling impurity removal matter:
Impure silicon carbide/silicon mixture is soaked the acidic solution that places acidic solution or include auxiliary agent, by the impurity in acid leach solution silicon carbide/silicon mixture, refilter and remove the acidic solution that is dissolved with impurity, obtain preliminary silicon carbide/silicon mixture of removing impurity;
4) stir
Silicon carbide/silicon mixture of removing impurity is added in the water medium of pH2.5~14, and leave standstill after stirring, obtain sedimentary silicon carbide/silicon mixture and be suspended with the liquid medium of silicon, after filtration sedimentary silicon carbide/silicon mixture separation is gone out, obtain the silicon carbide/silicon mixture of initial gross separation silicon;
The liquid medium that is suspended with silicon is filtered, the filtering liquid medium obtains silicon, silicon is added in the acidic solution, with the impurity in the dissolves silicon, after filtering is dissolved with the acidic solution of impurity again, obtain the silicon of purifying, or carry out the electromagnetism high intensity magnetic separation and be coated with the silicon of magnetic-particle with removal, this acidic solution of filtering is to obtain the silicon behind the purifying again.
5) silicon dissolving:
Silicon carbide/silicon mixture of removing impurity is placed basic solution, make basic solution dissolve silicon in this silicon carbide/silicon mixture, obtain to be dissolved with the basic solution and the silicon carbide precipitation of silicon;
6) alkali lye is removed:
Remove the basic solution that this is dissolved with silicon,, obtain the silicon carbide of purifying with flushing with clean water silicon carbide precipitation.
The recovery method of one of recovery method of above-mentioned silicon carbide or silicon carbide two 3) acidic solution described in the pickling impurity removal matter step, be hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid or its mixture; Described auxiliary agent is a hydrogen peroxide.
Basic solution is sodium hydroxide, ammoniacal liquor and/or potassium hydroxide aqueous solution described in two the silicon dissolving step of the recovery method of one of recovery method of above-mentioned silicon carbide or silicon carbide.
In the two described silicon dissolving steps of the recovery method of one of recovery method of above-mentioned silicon carbide or silicon carbide, in being dissolved with the basic solution of silicon, feed carbonic acid gas, perhaps add hydrochloric acid, nitric acid, sulfuric acid or/and hydrofluoric acid aqueous solution, so that the silicon in this basic solution precipitates formation silica gel because of acidifying, after this silica gel separation, silica gel is carried out roasting, obtain silicon-dioxide.
The present invention's beneficial effect compared with the prior art is:
1. the recovery method of silicon carbide of the present invention need not use sepa-ration aid in the filtration step, therefore can reduce power consumption and cost recovery, makes the dispersion liquid that reclaims can not produce rotten problem and can directly reclaim use simultaneously.
2. the recovery method of the present invention's silicon carbide, alkali lye is removed the basic solution that is dissolved with silicon that step obtained, and obtains silica gel through acidifying, perhaps filters roasting again and just can obtain recovery of silica and use.
3. the recovery method of silicon carbide of the present invention stirs by this whipping step, utilizes the particle size of silicon carbide and silicon and difference of specific gravity to make the two carry out initial gross separation, therefore need not use as expensive device such as supercentrifuges, can reduce cost recovery; Also need not with an organic solvent separate this silicon carbide and silicon.And the silicon that is suspended in this liquid medium is also recyclable, reduces material loss.
Therefore, the recovery method of the present invention's silicon carbide can reclaim silicon and dispersion liquid simultaneously at recovery silicon carbide, therefore can reach the recycled in its entirety rate that promotes, reduces cost recovery and reduce the effect that material is wasted.
Description of drawings
Fig. 1 is the schematic flow sheet of one of recovery method of a kind of silicon carbide of the present invention.
Among the figure: filtration step S1, raffinate is removed step S2, pickling impurity removal step S3, silicon dissolving step S4, alkali lye is removed step S5.
Fig. 2 is two a schematic flow sheet of the recovery method of a kind of silicon carbide of the present invention.
Among the figure: filtration step S1, raffinate is removed step S2, pickling impurity removal step S3, whipping step S21, silicon dissolving step S4, alkali lye is removed step S5.
Embodiment
Below in conjunction with preferred embodiment of the present invention and accompanying drawing the present invention is elaborated.
Embodiment 1
One of recovery method of silicon carbide of the present invention
Shown in 1 figure, the recovery method of silicon carbide comprises filtration step S1, raffinate is removed step S2, pickling impurity removal step S3, silicon dissolving step S4 and alkali lye and removed step S5.
1. filtration step S1
(1) the siliceous mortar that will comprise silicon carbide, silicon, impurity and dispersion liquid filters, and obtains the silicon carbide/silicon mixture of preliminary filtering dispersion liquid;
In more detail, siliceous mortar is the cutting waste fluid of cutting silicon crystal bar, therefore siliceous mortar includes the composition of silicon carbide, silicon and dispersion liquid, this dispersion liquid is general cutting liquid commonly used, polyoxyethylene glycol cutting fluids such as (PEG) for example, may also include other impurity in the siliceous mortar, for example the chip that cutting tool produced, the normally impurity such as chip of iron filings or other metal.Present embodiment is that this siliceous mortar is filtered, and for example can select with collecting and filtering apparatus or membrane filter siliceous mortar to be filtered, and with the preliminary filtering of dispersion liquid, and acquisition includes the silicon carbide/silicon mixture of the preliminary filtering dispersion liquid of silicon carbide and silicon composition.Because this filtration step S1 only carries out preliminary solid-liquid separation to this liquid dispersion liquid and solid-state silicon carbide and silicon composition, therefore, need not additionally add sepa-ration aid (for example water), not only can reduce cost recovery, also make the dispersion liquid of filtering can directly reclaim use, need not worry to cause the rotten problem of machining oil because of the interpolation of sepa-ration aid.
2. raffinate is removed step S2
Silicon carbide/silicon mixture is heated, and temperature>250 ℃ make residual dispersion liquid volatilization, obtain silicon carbide/silicon mixture; This silicon carbide/silicon mixture is placed acidic solution, further dissolve impurity wherein, filtering is dissolved with the impurity acidic solution, obtains to remove impurity silicon carbide/silicon mixture.
In more detail, filtration step S1 only tentatively carries out solid-liquid separation, and still remaining in silicon carbide/silicon mixture have a part dispersion liquid, therefore further to silicon carbide/silicon mixture heating up to residual dispersion liquid volatilization and remove.For example, present embodiment is selected be somebody's turn to do preliminary silicon carbide/silicon mixture of removing impurity and is placed that pyrolyzer is interior to distill heating with temperature more than 250 ℃, make that remaining dispersion liquid evaporates into the pyrolyzer top in the silicon carbide/silicon mixture of preliminary removal impurity, collected gaseous state dispersion liquid can utilize the differential condensation of boiling point to reclaim to use above this pyrolyzer.Just can obtain silicon carbide/silicon mixture after silicon carbide/silicon mixture heating up, this silicon carbide/silicon mixture is placed acidic solution, further dissolve impurity wherein, filtering is dissolved with the acidic solution of impurity, obtains to remove the silicon carbide/silicon mixture of impurity.
3. pickling impurity removal step S3
Impure silicon carbide/silicon mixture is soaked the acidic solution that places acidic solution or include auxiliary agent, by the impurity in acid leach solution silicon carbide/silicon mixture, refilter and remove the acidic solution that is dissolved with impurity, obtain preliminary silicon carbide/silicon mixture of removing impurity.
In more detail, because silicon carbide/silicon mixture still may contain aforesaid impurity, therefore silicon carbide/silicon mixture is preferably to soak and places acidic solution (for example hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid or its mixture etc.), by the impurity in this acid leach solution silicon carbide/silicon mixture, after removal is dissolved with the acidic solution of impurity again, for example remove this acidic solution, just can obtain tentatively to remove the silicon carbide/silicon mixture of impurity, carry out subsequent step again with filter type.Wherein, be preferably in this acidic solution and include auxiliary agent in addition, auxiliary agent such as hydrogen peroxide for example is to improve the dissolved efficiency of this acidic solution to this impurity.For example, present embodiment is that to select concentration be 3M sulfuric acid and to add concentration be that the 1wt% hydrogen peroxide is as this acid leach solution impurity.
3. silicon dissolving step S4
Silicon carbide/silicon mixture of removing impurity is placed basic solution, make basic solution dissolve silicon in this silicon carbide/silicon mixture, obtain to be dissolved with the basic solution and the sedimentary silicon carbide of silicon.
In more detail, owing to still contain the composition of silicon in silicon carbide/silicon mixture, therefore, present embodiment places basic solution (for example sodium hydroxide (NaOH), ammoniacal liquor (NH with silicon carbide/silicon mixture 4OH), potassium hydroxide (KOH) basic solution or its mixture) in, by basic solution with the silicon composition stripping in silicon carbide/silicon mixture.Present embodiment be with concentration be the 2M aqueous sodium hydroxide solution as basic solution, make silicon composition in silicon carbide/silicon mixture will be dissolved in the sodium hydroxide solution and form sodium silicate solution.
4. alkali lye is removed step S5
Removal is dissolved with the basic solution of silicon, with the sedimentary silicon carbide of flushing with clean water, obtains the silicon carbide of purifying.
In more detail, by basic solution with the silicon stripping after, again basic solution is removed, for example present embodiment is a basic solution of selecting to be dissolved with the filter type filtering silicon, just can obtain the silicon carbide behind the purifying.Wherein, after filtering is dissolved with the basic solution of silicon, with this silicon carbide of flushing with clean water, to avoid the residual of this basic solution.So far, just finish one of the recovery method of silicon carbide of the present invention.
In addition, carry out acidifying by the basic solution that this is dissolved with silicon in addition, just can produce precipitation and acquisition silica gel.For instance, present embodiment is by feeding carbonic acid gas in being dissolved with the basic solution of silicon, perhaps adding acidic solution as the aforementioned, making the silicon in the basic solution precipitate formation silica gel because of acidifying, and is just recyclable after silica gel is separated; Perhaps, further use the solution of a kind of ionogen (for example ionogen such as ammonium chloride or sodium-chlor) that silica gel is washed again at least, avoiding acidic solution residual, and carry out roasting 2 hours with 300 ℃ of temperature again after silica gel taken out after filtration, just can obtain silicon-dioxide.So, just institute's dissolved silicon in the basic solution can be converted into silica gel or recovery of silica and use, to avoid the waste of material.
Embodiment 2
Two of the recovery method of silicon carbide of the present invention
Shown in 2 figure, two of the recovery method of silicon carbide of the present invention comprises filtration step S1, raffinate is removed step S2, pickling impurity removal step S3, whipping step S21, silicon dissolving step S4, alkali lye removal step S5.
1. filtration step S1 is identical with embodiment 1 described filtration step S1.
2. raffinate removal step S2 is identical with embodiment 1 described raffinate removal step S2.
3. pickling impurity removal step S3 is identical with embodiment 1 described pickling impurity removal step S3.
4. whipping step S21
Silicon carbide/silicon mixture of removing impurity is added in the water medium of pH2.5~14, and leave standstill after stirring, obtain sedimentary silicon carbide/silicon mixture and be suspended with the liquid medium of silicon, after filtration sedimentary silicon carbide/silicon mixture separation is gone out, obtain the silicon carbide/silicon mixture of initial gross separation silicon.
In more detail, after finishing raffinate removal step S2, leave standstill after placing this liquid medium to stir this silicon carbide/silicon mixture, for example, present embodiment system selects this silicon carbide/silicon mixture is placed in the water of pH2.5~14, and agitator selects the rotating speed of 100~3000rpm to stir.Because the proportion of this silicon carbide is bigger than silicon, and it is same sex electric charge that the boundary of this silicon carbide and silicon reaches current potential, therefore, the silicon that evenly stirs back silicon carbide and small part will be that the same sex is repelled each other because of the surface charge of silicon carbide and silicon, make silicon carbide can faster separate with silicon, again and, because the proportion of this silicon carbide is bigger, therefore can with the silicon of part faster precipitation and form silicon carbide/silicon mixture, and most silicon will be suspended in this liquid medium, after separating by gravity settling tank again, but just initial gross separation silicon carbide and silicon.Should sedimentary silicon carbide/after the silicon mixture takes out, just can carry out follow-up silicon dissolving step S4 and alkali lye and remove step S5.
And the liquid medium that is suspended with silicon will just can obtain silicon after the liquid medium filtering after filtration.For example, present embodiment be with membrane filter with the liquid medium filtering after, just obtain silica flour for reclaim using.Wherein, silicon cleans with acidic solution again, for example present embodiment is that sulphuric acid soln with 20wt% cleans, further to remove the impurity (for example iron filings) in the silica gel by this acidic solution, can't be owing to have that part tool magnetic impurity is coated by silica flour by this acid leach solution, therefore, other carries out the electromagnetism high intensity magnetic separation, can't dissolved impurity by strong magnetic force magnetic acidic solution, for example present embodiment is can't dissolved impurity with this acidic solution of high-intensity magnetic field magnetic of 2T (Fesla) intensity, to promote the removal effect of impurity in this silicon, just can obtain highly purified silicon, use for reclaiming silicon.
1. silicon dissolving step S4 is identical with embodiment 1 described silicon dissolving step S4.
5. alkali lye removal step S5 is identical with embodiment 1 described alkali lye removal step S5.
Though the present invention has utilized above-mentioned preferred embodiment to disclose; yet; it is not in order to limiting the present invention, anyly has the knack of this skill person and is not breaking away within the spirit and scope of the present invention, and the foregoing description carries out various changes and revises the technology category that still belongs to the present invention and protected relatively.

Claims (5)

1. the recovery method of a silicon carbide is characterized in that, is that siliceous mortar contains silicon carbide, silicon, impurity and dispersion liquid to the recovery method of silicon carbide in the siliceous mortar; The method steps that reclaims silicon carbide wherein is as follows:
1) filter:
The siliceous mortar that will comprise silicon carbide, silicon, impurity and dispersion liquid filters, and obtains the impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture;
2) raffinate is removed:
The impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture is heated, and temperature>250 ℃ make residual dispersion liquid volatilization, obtain impure silicon carbide/silicon mixture;
3) pickling impurity removal matter:
Impure silicon carbide/silicon mixture is soaked the acidic solution that places acidic solution or include auxiliary agent, by the impurity in acid leach solution silicon carbide/silicon mixture, refilter and remove the acidic solution that is dissolved with impurity, obtain preliminary silicon carbide/silicon mixture of removing impurity;
4) silicon dissolving:
Silicon carbide/silicon mixture of removing impurity is placed basic solution, make basic solution dissolve silicon in this silicon carbide/silicon mixture, obtain to be dissolved with the basic solution and the silicon carbide precipitation of silicon;
5) alkali lye is removed:
Removal is dissolved with the basic solution of silicon, obtains the silicon carbide of purifying.
2. the recovery method of a silicon carbide is characterized in that, is that siliceous mortar contains silicon carbide, silicon, impurity and dispersion liquid to the recovery method of silicon carbide in the siliceous mortar; The method steps that reclaims silicon carbide wherein is as follows:
1) filter:
The siliceous mortar that will comprise silicon carbide, silicon, impurity and dispersion liquid filters, and obtains the impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture;
2) raffinate is removed:
The impure silicon carbide of preliminary filtering dispersion liquid/silicon mixture is heated, and temperature>250 ℃ make residual dispersion liquid volatilization, obtain impure silicon carbide/silicon mixture;
3) pickling impurity removal matter:
Impure silicon carbide/silicon mixture is soaked the acidic solution that places acidic solution or include auxiliary agent, by the impurity in acid leach solution silicon carbide/silicon mixture, refilter and remove the acidic solution that is dissolved with impurity, obtain preliminary silicon carbide/silicon mixture of removing impurity;
4) stir
Silicon carbide/silicon mixture of removing impurity is added in the water medium of pH2.5~14, and leave standstill after stirring, obtain sedimentary silicon carbide/silicon mixture and be suspended with the liquid medium of silicon, after filtration sedimentary silicon carbide/silicon mixture separation is gone out, obtain the silicon carbide/silicon mixture of initial gross separation silicon;
The liquid medium that is suspended with silicon is filtered, the filtering liquid medium obtains silicon, silicon is added in the acidic solution, with the impurity in the dissolves silicon, after filtering is dissolved with the acidic solution of impurity again, obtain the silicon of purifying, or carry out the electromagnetism high intensity magnetic separation and be coated with the silicon of magnetic-particle with removal, this acidic solution of filtering is to obtain the silicon behind the purifying again.
5) silicon dissolving:
Silicon carbide/silicon mixture of removing impurity is placed basic solution, make basic solution dissolve silicon in this silicon carbide/silicon mixture, obtain to be dissolved with the basic solution and the silicon carbide precipitation of silicon;
6) alkali lye is removed:
Remove the basic solution that this is dissolved with silicon,, obtain the silicon carbide of purifying with flushing with clean water silicon carbide precipitation.
3. according to the recovery method of claim 1 or the described silicon carbide of claim 2, it is characterized in that 3) acidic solution described in the pickling impurity removal matter step is hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid or its mixture; Described auxiliary agent is a hydrogen peroxide.
4. according to the recovery method of claim 1 or the described silicon carbide of claim 2, it is characterized in that basic solution described in the silicon dissolving step is sodium hydroxide, ammoniacal liquor and/or potassium hydroxide aqueous solution.
5. according to the recovery method of claim 1 or the described silicon carbide of claim 2, it is characterized in that, described silicon dissolving step Hou, in being dissolved with the basic solution of silicon, feed carbonic acid gas, perhaps add hydrochloric acid, nitric acid, sulfuric acid or/and hydrofluoric acid aqueous solution, so that the silicon in this basic solution precipitates formation silica gel because of acidifying, after this silica gel separated, silica gel is carried out roast, obtain silicon-dioxide.
CN 201110021374 2011-01-12 2011-01-12 Recycling method of silicon carbide Pending CN102079520A (en)

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CN103528874A (en) * 2013-09-26 2014-01-22 镇江耐丝新型材料有限公司 Separating method of carborundum particles on surface of diamond wire
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CN103030144A (en) * 2011-09-28 2013-04-10 汇隆科技有限公司 Method for recovering silicon carbide in waste liquid
CN103896425A (en) * 2012-12-29 2014-07-02 陕西华浩科技有限公司 Polycrystalline silicon wastewater treatment device and method
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CN103528874A (en) * 2013-09-26 2014-01-22 镇江耐丝新型材料有限公司 Separating method of carborundum particles on surface of diamond wire
CN106957060A (en) * 2016-01-12 2017-07-18 光宇材料股份有限公司 The application method and the product by its acquisition of useless silicon mud
CN111939640A (en) * 2020-09-11 2020-11-17 连云港秉文科技有限公司 Separation and recovery device for silicon carbide micro-powder waste and control system thereof

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Application publication date: 20110601