Method for regenerating sapphire raw material and regenerated sapphire
阅读说明：本技术 蓝宝石原料再生的方法和再生蓝宝石 (Method for regenerating sapphire raw material and regenerated sapphire ) 是由 陈招海 陈振宇 林太顺 于 2021-07-22 设计创作，主要内容包括：本发明公开了一种蓝宝石原料再生的方法和再生蓝宝石,蓝宝石原料再生的方法,包括以下步骤：将蓝宝石切割研磨工艺得到的废浆料经过第一次固液分离得到切割废渣,切割废渣经过有机溶剂洗涤、第二次固液分离、水洗、第三次固液分离得到固态废料；将固态废料通氧化气流在800～1000℃氧化得到氧化处理后的混合物；将上述氧化处理后的混合物经过酸液洗涤,再经过水洗、烘干得到蓝宝石原料。本申请能够有效地回收废浆料中的α-Al-2O-3粉末,回收得到的蓝宝石原料中α-Al-2O-3粉末纯度不低于99.995%,能够作为蓝宝石晶体生长工艺中的原料生产蓝宝石。(The invention discloses a sapphire raw material regeneration method and a method for regenerating sapphire, wherein the sapphire raw material regeneration method comprises the following steps: carrying out first solid-liquid separation on waste slurry obtained by the sapphire cutting and grinding process to obtain cutting waste residues, and carrying out organic solvent washing, second solid-liquid separation, water washing and third solid-liquid separation on the cutting waste residues to obtain solid waste; oxidizing the solid waste by introducing oxidizing gas flow at 800-1000 ℃ to obtain a mixture after oxidation treatment; and washing the mixture subjected to the oxidation treatment with acid liquor, washing with water, and drying to obtain the sapphire raw material. The method can effectively recover alpha-Al in the waste slurry 2 O 3 Powder, recovery of alpha-Al in the sapphire raw material 2 O 3 The purity of the powder is not less than 99.995 percent, and the powder can be used in the growth process of sapphire crystalsProducing sapphire from raw materials.)
1. A method for regenerating sapphire raw material is characterized by comprising the following steps: the method comprises the following steps:
solid-liquid separation: carrying out first solid-liquid separation on waste slurry obtained by the sapphire cutting and grinding process to obtain cutting waste residues, and carrying out organic solvent washing, second solid-liquid separation, water washing and third solid-liquid separation on the cutting waste residues to obtain solid waste;
oxidation treatment: oxidizing the solid waste material by oxidizing air flow at 800-1000 ℃ to obtain a mixture after oxidation treatment, wherein the oxygen partial pressure in the oxidation process is not more than 10-2Pa；
Acid washing for impurity removal: and washing the mixture subjected to oxidation treatment with an acid solution, washing with water, and drying to obtain the sapphire raw material, wherein the acid solution used in the acid solution washing contains hydrofluoric acid, and the pH value of the acid solution is 1-3.
2. The method for regenerating sapphire raw material according to claim 1, characterized in that: and in the oxidation treatment step, the oxidation gas flow is a mixed gas consisting of pure oxygen and argon.
3. The method for regenerating sapphire raw material according to claim 1, characterized in that: the blowing flow speed of the oxidizing air flow in the oxidizing treatment step is 60-300L/h.
4. The method for regenerating sapphire raw material according to claim 1, characterized in that: and the blowing time of the oxidizing air flow in the oxidizing treatment step is 4-6 h.
5. The method for regenerating sapphire raw material according to claim 1, characterized in that: and in the acid washing impurity removal step, the strong acid is one or more of hydrochloric acid, sulfuric acid and nitric acid.
6. The method for recycling the sapphire raw material according to claim 5, wherein: the concentration of hydrofluoric acid in the step of acid cleaning and impurity removing is 30-40 wt%.
7. The method for regenerating sapphire raw material according to claim 1, characterized in that: in the step of acid washing impurity removal, any one of ultrasonic acid washing or microwave acid washing is adopted for acid washing.
8. The method for recycling the sapphire raw material as set forth in claim 7, wherein: the frequency of ultrasonic pickling in the pickling impurity removal step is 40-70 KHz, and the ultrasonic pickling time is 2-3 h.
9. The method for recycling the sapphire raw material as set forth in claim 7, wherein: the power of the microwave pickling in the pickling and impurity removing step is 10-50 KW, and the microwave pickling time is 1.5-3 h.
10. A regenerated sapphire produced by treating a sapphire raw material obtained by the method for regenerating a sapphire raw material according to any one of claims 1 to 9.
Technical Field
The invention relates to the technical field of crystal manufacturing, in particular to a method for regenerating a sapphire raw material and regenerated sapphire.
Background
Sapphire is a trigonal crystal, the Mohs hardness of the crystal is as high as 9.0, and the special lattice structure of the crystal determines that the crystal has excellent mechanical properties, chemical stability and optical characteristics, so that the sapphire is an excellent LED (light-emitting diode) illuminating material and window material. With the widespread use of sapphire, the consumption of sapphire is increasing day by day.
Generally, sapphire grows from a seed crystal into a large-size crystal, and the large-size crystal is ground into a rod shape or a sheet shape by cutting according to actual production requirements. In the cutting and grinding process, the generated sapphire scraps and liquid substances such as auxiliaries, cleaning agents and the like form waste slurry. At present, sapphire processing enterprises generally treat the waste slurry according to the treatment standard of hazardous wastes, and the treatment difficulty is high and the treatment cost is high. At present, the recycling process of sapphire waste is rarely reported in the market.
Disclosure of Invention
In order to fully recycle sapphire waste, the application provides a sapphire raw material regeneration method and regenerated sapphire.
In a first aspect, the present application provides a method for regenerating a sapphire raw material, which adopts the following technical scheme:
a method for regenerating sapphire raw material comprises the following steps:
solid-liquid separation: carrying out first solid-liquid separation on waste slurry obtained by the sapphire cutting and grinding process to obtain cutting waste residues, and carrying out organic solvent washing, second solid-liquid separation, water washing and third solid-liquid separation on the cutting waste residues to obtain solid waste;
oxidation treatment: oxidizing the solid waste material by oxidizing air flow at 800-1000 ℃ to obtain a mixture after oxidation treatment, wherein the oxygen partial pressure in the oxidation process is not more than 10-2Pa；
Acid washing for impurity removal: and washing the mixture subjected to oxidation treatment with an acid solution, washing with water, and drying to obtain the sapphire raw material, wherein the acid solution used in the acid solution washing contains hydrofluoric acid, and the pH value of the acid solution is 1-3. .
According to the technical scheme, the nickel electroplated diamond wire is used as a cutting wire of a cutting machine in the cutting and grinding process, the sapphire crystal is held and fixed by a plate containing silicon dioxide and silicon carbide, ethylene glycol and white oil are used as auxiliaries, water is used as a cleaning agent, cutting is carried out, and waste slurry is collected after cutting is finished.
The waste slurry is composed of solid waste mainly comprising diamond particles, silicon carbide particles, silica particles and nickel particles and liquid waste, typically a mixture of ethylene glycol and white oil. The waste slurry is subjected to solid-liquid separation, then washed by an organic solvent, the organic solvent fully dissolves residual liquid waste in the solid cutting waste residue, and finally the solid waste is subjected to solid-liquid separation for the third time after washing and cleaning to obtain solid waste, so that the influence of the organic solvent doped in the solid waste on the subsequent oxidation treatment of the solid waste is avoided.
The solid waste material and oxygen are subjected to oxidation reaction in the environment of high temperature and low oxygen partial pressure, the diamond particles can be combusted to generate gaseous oxide when reaching 800 ℃, the gaseous oxide is discharged along with the oxidation airflow, and a large amount of carbon elements are separated from the waste material. The silicon carbide particles generate mainly silicon monoxide gas in the low oxygen partial pressure environment, and the silicon monoxide gas is discharged with the oxidizing gas flow to separate part of silicon elements from the waste materials. The nickel particles are oxidized at the reaction temperature of 800-1000 ℃ to generate active nickel monoxide, so that the subsequent nickel element and alpha-Al can be conveniently generated2O3Separation is carried out. The mixture after oxidation treatment mainly contains alpha-Al2O3The powder also comprises nickel oxide, silicon dioxide and a small amount of silicon carbide which is not completely reacted.
During the acid cleaning and impurity removing process, due to alpha-Al2O3Is a cubic crystal of a-Al2O3Form a compact space structure, have stable properties, and are difficult to attack alpha-Al by hydrogen bonds and a large amount of hydrogen ions of hydrofluoric acid in the acid solution2O3Covalent bond of (A) to (A-Al)2O3Ionization, and thus, the acid washing with an acid solution can dissolve nickel monoxide, silica and a small amount of silicon carbide in the oxidized mixture, so that nickel monoxide, silica and silicon carbide and α -Al are mixed2O3Separating to obtain coarse alpha-Al2O3Coarse alpha-Al2O3Washing and drying to obtain the sapphire raw materialalpha-Al in sapphire raw material2O3The purity of the crystal reaches more than 99.995 percent, and the crystal meets the standard of being used as a raw material for growing sapphire single crystals.
Therefore, the application is directed to a large amount of alpha-Al generated in the sapphire cutting process2O3The waste materials are effectively recycled, the high-purity sapphire raw materials are obtained, the high-purity sapphire raw materials can be put into a sapphire production process, the sapphire production cost is reduced, the recycling process flow is short, the efficiency is high, and the industrial use is easy.
Preferably, the oxidizing gas flow in the oxidizing treatment step is a mixed gas of pure oxygen and argon.
Preferably, the blowing flow speed of the oxidizing gas flow in the oxidizing treatment step is 60-300L/h.
By adopting the technical scheme, the blowing flow rate of the oxidation air flow is controlled, the fluctuation of the reaction temperature in the oxidation treatment process is reduced, and the temperature of the oxidation reaction is kept within 800-1000 ℃.
Preferably, the blowing time of the oxidizing gas flow in the oxidizing treatment step is 4-6 h.
By adopting the above technical scheme, the composition of each oxide in the mixture after the oxidation treatment is almost unchanged beyond the blowing time, and therefore, the energy is saved in the blowing time range.
Preferably, the strong acid in the acid washing impurity removal step is one or more of hydrochloric acid, sulfuric acid and nitric acid.
Preferably, the concentration of hydrofluoric acid in the acid cleaning impurity removal step is 30-40 wt%.
Preferably, in the step of acid washing and impurity removing, the acid washing adopts any one of ultrasonic acid washing or microwave acid washing.
Preferably, the frequency of ultrasonic pickling in the pickling and impurity removing step is 40-70 KHz, and the time of ultrasonic pickling is 2-3 h.
Preferably, the power of the microwave pickling in the pickling and impurity removing step is 10-50 KW, and the microwave pickling time is 1.5-3 h.
On one hand, ultrasonic pickling and microwave pickling can both accelerate pickling and impurity removalThe reaction rate among all reaction raw materials in the process is improved, so that the dissolving efficiency of the acid liquid containing hydrofluoric acid is improved, on the other hand, the solid-liquid contact is fully realized, the impurity removal amount is improved, and the alpha-Al content in the sapphire raw material is further improved2O3The purity of (2).
In the application, the solid-liquid separation step can be separated by using processes such as vacuum filtration, centrifugal separation, plate-and-frame filter pressing and the like, preferably, the vacuum filtration is used for carrying out solid-liquid separation, wherein the vacuum filtration uses an ultrafiltration membrane with the aperture of 50nm or 100nm for carrying out filtration.
The organic solvent used in the solid-liquid separation step includes but is not limited to volatile solvents such as ethanol and pentane, and the washing times of the organic solvent are not less than 3 times. In the water washing process, the separated cutting waste residues are washed by hot water (the water temperature is 40-80 ℃), so that the volatilization of an organic solvent is promoted, and the washing efficiency and the washing quality are improved. The washing times are not less than 3.
In a second aspect, the present application provides a regenerated sapphire, which adopts the following technical scheme:
a regenerated sapphire is prepared from the sapphire raw material obtained by the method for regenerating the sapphire raw material.
By adopting the technical scheme, the alpha-Al is obtained by the method for regenerating the sapphire raw material2O3The method for preparing the regenerated sapphire from the powder has the advantages of low manufacturing cost of the regenerated sapphire, good quality of the regenerated sapphire and high purity alpha-Al used in the traditional process2O3The quality of the sapphire prepared by using the raw material is not greatly different.
In summary, the present application has the following beneficial effects:
1. the method comprises the steps of washing waste slurry with an organic solvent for multiple times and washing the waste slurry with water for multiple times, carrying out solid-liquid separation to obtain solid waste, carrying out oxidation treatment on the solid waste to change metal nickel into nickel monoxide, and change particles such as non-metal diamond, silicon carbide, silicon dioxide and the like into gaseous oxides, discharging the gaseous oxides along with oxidation airflow, realizing gas-solid separation, removing impurities such as diamond, silicon carbide, silicon dioxide and the like, and obtaining a mixture after the oxidation treatment; pickling the mixture with acid solution to obtain acid solutionThe hydrofluoric acid in the reaction solution dissolves silicon dioxide and a small amount of silicon carbide in the mixture after the oxidation treatment, and nickel monoxide is dissolved in strong acid, so that a sapphire raw material can be obtained through solid-liquid separation, and alpha-Al in the sapphire raw material2O3The purity of the powder can reach more than 99.995 percent after being washed and dried for many times, and the powder can be used for a sapphire crystal growth process.
2. This application is through the velocity of flow of control oxidation air current and the time of ventilating of oxidation air current, under the prerequisite of guaranteeing the abundant oxidation of solid waste material, the energy saving.
3. By adopting ultrasonic pickling or microwave pickling, the reaction rate in the pickling and impurity removing process can be increased, the impurity removing efficiency is improved, and meanwhile, the alpha-Al content in the sapphire raw material is improved2O3Purity of the powder.
Detailed Description
The waste slurry in the following examples was derived from the following cutting and grinding process:
in the cutting and grinding process, an electroplated nickel diamond wire is used as a cutting wire of a cutting machine, a sapphire crystal is held and fixed by a plate containing silicon dioxide and silicon carbide, cutting is carried out by adopting glycol and white oil as auxiliaries and water as a cleaning agent, and waste slurry is collected after cutting is finished.
Example 1
A method for regenerating sapphire raw material comprises the following steps:
solid-liquid separation:
and (3) taking 100kg of the waste slurry, performing suction filtration through a vacuum suction filter, wherein the aperture of a filter membrane used in the vacuum suction filter is 100nm, and filtering to obtain the cutting waste residue.
And putting the cutting waste residues into an organic solvent washing tank, washing by using 75 wt% ethanol water solution, carrying out vacuum filtration, and repeating the washing and vacuum filtration for 3 times to obtain the solid waste material washed by the organic solvent.
Heating water to 60 ℃, putting the solid waste washed by the organic solvent into hot water for washing, then carrying out vacuum filtration, and repeating the washing and vacuum filtration for 3 times to obtain clean solid waste.
Using X-ray fluorescence spectroscopy semi-quantitative analysis to determine the main elements and contents in the clean solid waste, the specific elements and corresponding contents are shown in table 1 below:
TABLE 1 elemental and content in solid waste (XRF test results)
Components
Content/%
Components
Content/%
Al
96.0645
Ni
0.6933
Si
1.5326
C
1.6827
Other hetero elements
0.0969
Oxidation treatment:
and putting the clean solid waste into a vacuum induction furnace. The vacuum induction furnace is firstly vacuumized, and the total pressure in the furnace is controlled to be 5 multiplied by 10-3Pa, introducing an oxidizing gas flow formed by mixing pure oxygen and argon according to the gas pressure ratio of 1:5, wherein the blowing rate of the oxidizing gas flow is 60L/h, and the total gas pressure in the furnace is controlled to be not higher than 3 multiplied by 10-1Pa (oxygen partial pressure in vacuum induction furnace is less than 10)-2Pa) is added. The temperature of the induction furnace is raised to 800 ℃ at the heating rate of 50 +/-10 ℃/h, and the reaction is carried out for 6 h. And after the heat preservation reaction is finished, obtaining a mixture after oxidation treatment.
1g of clean solid waste and 1g of the mixture after oxidation treatment were taken, respectively, and the following tests were carried out: c content detection: taking 0.1g of the mixture after oxidation treatment, measuring the content of C by using a C-S analyzer, repeatedly measuring for 3 times, and taking an average value as C;
and (3) detecting the content of Si: taking 0.1g of the mixture after oxidation treatment, dissolving the mixture after oxidation treatment in 40wt% hydrofluoric acid solution by using a microwave digestion method to prepare a first sample injection solution with the concentration of 10 mug/ml, detecting by using an inductively coupled plasma emission spectrometer (ICP-OES), measuring the content of Si, repeatedly detecting for 3 times, and taking an average value as Si;
and (3) detecting the Ni content: drawing a standard curve of Ni, dissolving 0.1g of the mixture after oxidation treatment in nitric acid by adopting a microwave digestion method to prepare a detection solution with the concentration of 10 mu g/ml, determining the content of Ni by using a spectrophotometry, repeating the steps for 3 times, and taking an average value as Ni.
And (3) detecting the Al content: detecting the Al content in the mixture after the oxidation treatment by using an X-ray fluorescence spectrum;
the total amount of other undetected miscellaneous elements (such as F element, S element, etc.) is calculated to obtain the total amount of miscellaneous elements, and the detection and calculation results of the contents of the elements in the mixture after oxidation treatment are shown in table 2 below:
TABLE 2 elemental composition and content of the mixture after oxidation treatment
Components
Content/%
Components
Content/%
Al
98.6212
Ni
0.7721
Si
0.4346
C
0.0024
Other hetero elements
0.1697
Acid washing for impurity removal:
putting the mixture after the oxidation treatment into an ultrasonic pickling tank, putting an acid solution prepared by mixing 40wt% of hydrofluoric acid and 30 wt% of hydrochloric acid according to a weight ratio of 1:3 into the ultrasonic pickling tank, and soaking and pickling for 3 hours at 25 +/-5 ℃.
Standing for 2h after soaking and pickling are finished, settling the materials, and pumping the acid liquor after solid-liquid separation into a liquid storage tank to obtain acid-containing solids.
And (3) putting the acid-containing solid into hot water at 60 ℃ for water washing, then carrying out vacuum filtration, repeating the washing and vacuum filtration for 3 times, and drying at 100 ℃ to obtain the sapphire raw material.
Taking 1g of sapphire raw material to carry out the following detection:
c content detection: taking 0.1g of sapphire raw material, measuring the content of C by using a C-S analyzer, repeatedly measuring for 3 times, and taking an average value as C;
and (3) detecting the content of Si: taking 0.1g of sapphire raw material, dissolving the sapphire raw material in hydrofluoric acid with the concentration of 40wt% by using a microwave digestion method to prepare a sample injection liquid II with the concentration of 10 mu g/ml, detecting by using an inductively coupled plasma emission spectrometer (ICP-OES), measuring the content of Si, repeatedly detecting for 3 times, and taking an average value as Si;
and (3) detecting the Ni content: drawing a standard curve of Ni, dissolving 0.1g of sapphire raw material in nitric acid by adopting a microwave digestion method to prepare a detection solution with the concentration of 10 mu g/ml, determining the Ni content by using a spectrophotometry, repeating the steps for 3 times, and taking an average value as Ni.
And (3) detecting the Al content: detecting the Al content in the sapphire raw material by using an X-ray fluorescence spectrum;
the total amount of other non-detectable mixed elements is calculated, and the detection and calculation results of the content of each element in the sapphire raw material are shown in the following table 3:
TABLE 3 elemental composition and content of sapphire raw material
Components
Content/%
Components
Content/%
Al
99.9960
Ni
0.0003
Si
0.0016
C
0.0017
Other hetero elements
0.0004
alpha-Al in sapphire raw material2O3The purity of the powder is satisfied as a raw material for growing sapphire single crystal.
Examples 2 to 3
Examples 2 to 3 are different from example 1 in the oxidation reaction temperature, the blowing flow rate of the oxidizing gas flow and the blowing time in the oxidation treatment step, and specific parameters are shown in the following table 4.
TABLE 4 blowing flow rate and blowing time of the oxidizing gas flow in the oxidizing treatment step
Examples
Blowing flow rate of oxidizing gas stream/(L/h)
Blowing time/h of oxidizing gas flow
Temperature of oxidation reaction/. degree.C
Example 1
60
6
800
Example 2
180
5
900
Example 3
300
4
1000
TABLE 5 elemental composition and content of the mixture after oxidation treatment obtained in accordance with each example
Components
Al/％
Si/％
Ni/％
C/％
Other miscellaneous elements/%)
Example 1
98.6212
0.4346
0.7721
0.0024
0.1697
Example 2
98.6743
0.4646
0.7521
0.0025
0.1065
Example 3
98.6656
0.4446
0.7623
0.0022
0.1253
Examples 4 to 5
Examples 4 to 5 are different from example 1 in that the concentration of hydrofluoric acid used in the acid solution in the acid cleaning and impurity removing step was different, and the concentration of hydrofluoric acid used in the acid solution in example 4 was 35 wt%; example 5 the hydrofluoric acid used in the acid solution had a concentration of 30 wt%.
TABLE 6 elemental composition and content of sapphire raw material obtained for each example
Components
Al/％
Si/％
Ni/％
C/％
Other miscellaneous elements/%)
Example 1
99.9960
0.0016
0.0003
0.0017
0.0004
Example 4
99.9956
0.0013
0.0002
0.0019
0.0010
Example 5
99.9954
0.0015
0.0001
0.0021
0.0021
Example 6
Example 6 differs from example 1 in that the impurity removal was carried out by ultrasonic pickling at a frequency of 50KHz for a period of 3 hours.
Example 7
Example 7 differs from example 1 in that the removal of impurities was carried out using microwave pickling with a power of 30KW and a time of 3 h.
TABLE 7 elemental composition and content of sapphire raw material obtained in accordance with each example
Components
Al/％
Si/％
Ni/％
C/％
Other miscellaneous elements/%)
Example 1
99.9960
0.0016
0.0003
0.0017
0.0004
Example 6
99.9973
0.0007
0.0001
0.0017
0.0002
Example 7
99.9969
0.0011
0.0001
0.00161
0.0003
The inorganic acid in the embodiment of the application is purchased from Shandong Han Standard chemical Co.
The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.
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