TW201408602A - Full resource recycling treatment technique for waste cutting oil - Google Patents

Abstract

The present invention provides a full resource recycling treatment technique for waste cutting oil, which can recover three products: oil product, silicon micro-particles and silicon carbide micro-particles. The principle of the full resource recycling technique is described as follows: firstly, according to the oil being liquid, carrying out a solid-liquid separation of the waste cutting oil to separate oil from sludge, wherein the oil can be degraded to carry out secondary industrial utilization or can be incinerated to recover heat value, and the sludge is treated with a floating selection and contains silicon and silicon carbide as main components thereof; then according to the hydrophobic property of the surface of silicon particle and under the condition of controlled acidic pH value of coagulating silicon carbide particles, using a floating selection method to separate two solid components; extracting silicon from the floated ore and extracting silicon carbide from the precipitated ore; and using multiple fining selections to purify the floated ore and the precipitated ore step by step for obtaining two products: silicon having a grade of 99% and silicon carbide having a grade of 99.0%, thereby capable of being used in ceramic raw material or secondary industrial utilization of the same purpose.

Description

Full-scale resource processing technology for waste cutting oil

The invention relates to a full-scale resource treatment technology for waste cutting oil.

"Silicon Wafer" is a silicon wafer used in the integrated circuit manufacturing industry. Because it has a circular shape, it is called a germanium wafer. The germanium wafer is processed into various circuit component structures to become specific. Electrically integrated circuit (IC) products, such as: 矽 wafers after centrifugation, etching, heating, photoresist processing, coating, development and other hundreds of processing procedures, made dozens to several Hundreds of integrated circuits (ICs), after being tested, cut and packaged by semiconductor packaging and test factories, produce finished semiconductor products, and then handed them to manufacturers in various industries such as computers, motherboards and mobile phones to produce various consumer types. Electronic products, silicon wafer manufacturing is the most important part of China's integrated circuit industry. After the Republic of China, the self-sufficiency rate of silicon wafer materials in Taiwan has gradually increased, including: Sino-German Electronics, Taiwan Shin-Etsu, Taiwan Komatsu, Hejing Technology, Zhongmei Jingjing, Hanlei, Jiajing, Shengyang Technology, Jinmin Jingyan and Shangzhi Semiconductor, etc., mainly supply 8吋 and 6吋 of the wafer, polished, polished and regenerated矽 Wafer-based.

The wafer processing process is to slice the tantalum single crystal rod into a silicon wafer. The thickness of the slice is generally 600~800μm (a few 400~600 and 800~1000μm), while the thickness of the solar slice is 200~300μm. The cutting process uses wire saws (Wire Saw) for ingot cutting and wafer cutting The chip process must be added with a cutting agent mixed with cutting powder (SiC) and cutting oil (Epoxy, Glycol) for cooling purposes to take away the heat generated by the cutting process to improve product yield, which Wire Saw uses. The particle size of SiC powder is #1000 and #1200 (equivalent to 10~15μm), so the components of waste cutting oil produced by the slicing production unit are the following four types: 10~15μm niobium carbide particles, cutting oil (Epoxy, Glycol), antimony chips, Trace iron ions eluted from the wire saw.

The cutting oil used in the wafer manufacturing industry is a water-soluble cutting oil for abrasive cutting. The waste water-soluble cutting oil needs to be biologically treated, acidified, chemically coagulated, pyrolyzed, and electrolyzed. Treatment methods such as ultrafiltration, concentration separation or freeze separation, followed by secondary biological treatment.

Due to the high concentration of waste cutting oil, direct discharge into the wastewater treatment plant will increase the load on the wastewater treatment system and affect the quality of the treated water. Most factories will collect and store the waste liquid separately or entrust the waste treatment industry. Some The factory adopts evaporation and concentration and then external treatment, which can concentrate the cutting oil to less than 1/10 of the original volume.

Generally, the treatment technology for removing metal dust, grease and other impurities from cutting oil is called "filtration", but in fact it should be subdivided into two different treatment technologies: "filtration" and "separation". Waste cutting oil filtration and separation Equipment, separation technology is to use the physical properties of the separation object (such as different specific gravity) to remove impurities in the cutting oil, the filtration technology is to use the filter material to filter the solid impurities of the cutting oil, separation The easiest way to do this is to use a storage tank that collects cutting oil as a sedimentation tank for solid impurities, allowing the processing machine to flow out the cutting oil containing the dust, and use it in the storage tank before it is repeatedly returned to the machine. The sedimentation method is allowed to settle the large particles of the cutting oil in the bottom of the tank, and then manually removed, or the detachable filter collection basket is built in the storage tank to collect the powder for removing the sediment, but still some small. The dust will fall outside the collection basket and need to be further removed manually. If you want to completely remove the dust, you need to turn off the machine and empty the cutting oil before you can remove the dust. It is very labor-intensive. Time and will affect the productivity of mechanical equipment.

Due to the inclusion of bubbles, oil droplets and other chemicals in the cutting oil, the sedimentation speed of the dust is slowed down. Generally, particles with a pore diameter of more than 15 microns can settle in 7 to 10 minutes, but metal dust of less than 15 microns takes longer. It can be settled or even removed by natural gravity sedimentation. Therefore, existing hydraulic separators (Hydro-cyclons), telecentric separators (Screw Decanter Centrifuge) and magnetic separators, etc., hydraulic separators use centrifugal force to make the specific gravity larger. The powder and the like are separated and removed from the cutting oil having a small specific gravity, and the swirling vortex is generated by the flow velocity when the cutting oil flows into the separator, so that the metal particles in the cutting oil are thrown to the outer edge of the device by the centrifugal force, and The vortex direction of the edge is downward, so that the metal particles are led to the bottom of the separator, and the clean cutting oil will flow from the central part of the separator to the top, because the vortex speed of the separator depends on the cutting oil inflow speed, so Inlet velocity The faster the degree, the better the separation effect. The telecentric separator is used to separate two or more different kinds of dust. The same speed is used to separate the different speeds, and the centrifugal force generated can separate the solid and the liquid.

Although the inorganic sludge produced by the wafer manufacturing industry contains Si and SiC, the current domestic recycling performance is in its infancy, and almost all of them are disposed of by the cleaning and processing institutions.

For academic research, it is recommended to use the following general inorganic sludge recycling method for Si and SiC sludge.

A. Reuse in cement raw materials

Pure Si can be divided into amorphous and crystalline, the former can be burned in air, while the latter has a melting point of 1410 ° C, a boiling point of 2480 ° C, and SiC is decomposed at 2210 ° C, due to the formation of Si and SiC from the manufacture of tantalum wafers. Quite a lot of impurities, but also in the oxygen-rich cement kiln burning, should be combined with oxygen to form SiO ₂ , SiO ₂ is the main component of cement, so Si and SiC sludge can be used as cement raw materials.

B. reused in the grid when firing ceramics

The grid plate is a refractory plate in which the body is placed when the ceramic is fired. The characteristics of the refractory plate are high temperature resistance, fast heat conduction and deformation resistance. Previously, the mullite was used, and now the SiC plate is used. Si and SiC sludges also contain Al ₂ O ₃ , SiO ₂ , and ZrO _{2 which} are both refractory materials. Therefore, they can also be used as grid plates.

C. Reuse of brick raw materials

Since the main components of inorganic sludge are similar to brick raw materials, A part of the raw material can be replaced, and the recycling method is a method in which the sludge is blended into the soil for brick making as a resource.

D. Reuse of artificial aggregate raw materials

The recycling mechanism regenerates the waste into artificial aggregates. In order to make the non-harmful sludge easy to bond with the cement and achieve the compressive strength in the shortest time, it is in the manufacturing process, depending on the situation, the water is added to the flow. After the sludge is added, the patented sludge solidifying agent is added, which makes the internal water into a state of crystallization water instead of volatilization, and accelerates the drastic reduction of the internal moisture of the sludge, and the surface tension during the process of modifying the sludge particles by the wet sludge makes the cement easy Combined with sludge to achieve the purpose of curing.

The main object of the present invention is to provide a full-scale resource treatment technology for waste cutting oil, which can recover oil products, micro-particles and tantalum carbide, and can be used as fuel oil, ceramic raw materials, etc., or secondary industrial utilization.

The full-scale resource treatment technology of the waste cutting oil of the invention is that the waste cutting oil is separated by solid-liquid separation to separate the oil from the sludge, the oil can be reduced to the secondary industrial utilization, or the incineration is used to recover the calorific value, and the sludge is Flotation treatment, the product is taken out from the floating ore, and the product carbonized bismuth is taken out from the sinking ore, which can be used as a secondary ceramic raw material.

The solid-liquid separation of the present invention is for the purpose of taking out sludge having an oil content of 30% or less, and avoids excessive oil from interfering with the flotation separation of niobium carbide and niobium. The solid-liquid separation method may be static precipitation, pressure filtration, or heat drying.

The flotation treatment of the present invention comprises sequential treatment steps such as scrubbing treatment, slurry adjustment, and multiple selection.

The scrubbing treatment of the present invention is to put the sludge into the scrubbing tank, add a small amount of water to the scrubbing blade to work at a height, scrub at a high speed, and fully rub the sludge particles and the particles, which can act on the surface of the particle. The oil is wiped off, the surface of the particles is exposed to react with the flotation reagent, and the scrubbing time is at least 1500 rpm for at least 5 minutes.

The slurry adjustment of the present invention is to sequentially add a small amount of adjusting agent, collector kerosene, foaming agent and water to the scrubbed pulp, so that the surface of the cerium particles reacts with the adjusting agent to strengthen the surface hydrophobicity, which is favorable for kerosene capturing. At the same time, the adjusting agent is used to control the pH value of the slurry to 2-3, which is beneficial to the coagulation and sedimentation of the niobium carbide. The adjusting agent can be a mixed acid of hydrofluoric acid or hydrochloric acid, and the appropriate amount is added to adjust the pH. The amount of kerosene added is preferably 0.2 ml/100 g ore. The amount of addition depends on the concentration of the slurry, and the concentration of the slurry is preferably 10-30%.

The plurality of selections of the present invention are to put the flotation or sedimentation after flotation into the flotation tank, and adjust the slurry to make the slurry reach the above-mentioned better conditions, and then float again, and the selection can be gradually improved by using multiple selections. After three times of selection, the flotation can obtain a better product, the grade of 98.5-99%, and the better selection of the precipitate after three times of selection, the grade of niobium carbide is 98-99%.

The plurality of selections of the slurry for the multiple flotation operation include a flotation agent for the water, and the floating slurry or the slurry can be recycled. Water use, saving chemicals and water. The particles of floating pulp are only a few micrometers, which is relatively difficult to filter. It can control the better dehydration conditions. It can be mixed with PVA (polyvinyl alcohol) more than 200ppm for coagulation under pH 2-3, which is beneficial to its use. Filtration dewatering operation efficiency, the particle size of the slurry is about ten micron, the flotation condition is suitable for its coagulation, and it can directly filter and dehydrate.

The present invention is directed to a preferred embodiment of the present invention in order to achieve the above-mentioned objects of use and efficacy. The present invention is described in detail with reference to the drawings. The present invention provides a full amount of waste cutting oil. Recycling technology can recover oil products, as well as fine particles and tantalum carbide. The principle of full-scale resource treatment technology is as follows. As shown in Figure 1, the waste cutting oil is firstly separated by solid-liquid separation according to the oil being liquid. To separate the oil from the sludge, the oil can be reduced to secondary industrial utilization, or incinerated to recover the calorific value, and the sludge is further subjected to flotation treatment. The sludge composition is mainly composed of niobium carbide and niobium. The hydrophobic properties, and the acidic pH at which the cerium carbide particles are controlled, the two solid components (~1 micron cerium particles, ~15 micron cerium carbide particles) are separated by flotation, and the hydrazine is taken out from the floating ore. The products such as tantalum carbide are taken out from the sinking ore, and the floatation and sedimentation are gradually purified by multiple selections, and two products of 99% of tantalum grade and 99.0% of grade of tantalum carbide can be obtained respectively, which can be used as ceramic raw materials and Sub industrial use.

According to the full quantitative test results of waste cutting oil constituent materials, the composition of waste cutting oil is known (Table 1). Since waste cutting fluid is waste of high-tech industry, the main components are very simple, with volatile matter (oil) and carbonization. The content of the three is more than 99%, and the remaining traces of iron, potassium, calcium, copper, zinc, etc. are less than 1%. The solid waste material is analyzed after the waste cutting oil is dried, with aqua regia and concentrated. Fluoric acid is used to analyze the appearance of tantalum carbide (as shown in Fig. 2A, Fig. 2B) and particle size distribution (laser particle size analysis) after dissolving bismuth, and it is known that particles of ruthenium carbide d ₅₀ : 10-15 μm, d ₂₅ -d ₇₅ : 10 to 17 micron in nature. In addition, from the residue of the waste cutting oil drying, it was confirmed by electron microscopy (SEM/EDS) that the cerium particles were several micrometers in size, and the cerium was taken out from the slag of the upper layer of the waste cutting oil. d ₅₀ : 1-3 μm, d ₂₅ -d ₇₅ : 0.1 to 5 μm.

Since the tantalum carbide and niobium are very fine, the surface properties of the particles More significant, it is very suitable for flotation technology for sorting. The tantalum carbide and niobium are put into kerosene, and the surface lipophilicity of niobium is found to be stronger than that of carbonization. The literature indicates that the surface isoelectric point of niobium carbide is about pH2-3. According to the sedimentation experiment of the niobium carbide (Table 2), the sedimentation time is the shortest at pH 2.57, and the acidic environment is conducive to the coagulation of niobium carbide.

After the waste cutting oil was allowed to stand for several days, the sediment (oil content ~25%) was taken out from the bottom as the starting material for the flotation experiment, and the experimental results were based on the flotation conditions (Fig. 3A, Fig. 3B, Fig. 3C, Fig. 3D). The preferred flotation conditions are: scrubbing time>5min, pulp concentration 10~30wt%, collector<0.2ml/100g ore, adjusting agent<2ml/100g, according to the results of flotation experiment in Table 3, using adjustment The ferric acid mixed acid is adjusted to pH~2.3, and the flocculant kerosene and the foaming agent turpentine are floated to obtain better sorting results: 87% of the niobium carbide grade in the sedimentation, and the recovery rate of the niobium carbide is 85. %, the grade of tantalum carbide in the floating ore is 18.8%, and the recovery rate of tantalum carbide is 15% (ie, the grade of tantalum is 81.2%, and the recovery rate of tantalum is 84%).

Table 3: Results of flotation experiments at various pH Conditions: starting sludge 140g (oil content ~25%, dry sludge weight ~100g), SiC~56wt% (dry basis content); kerosene 0.5ml/100g, turpentine 0.1ml/100g, adjusting agent: hydrofluoric acid Hydrochloric acid is mixed with acid and sodium hydroxide.

According to the above flotation conditions, a number of selective experiments were carried out. The results are shown in Table 4 and Table 5. After three selections, the product with a tantalum carbide grade of up to 98% can be obtained from the sinking ore, the recovery rate is 99%, and the floating mine is also passed three times. Selected, the purified hydrazine product was obtained, the 矽 grade was 99.3%, and the recovery rate was 98%.

Condition: Each starting ore is 100g, repeated flotation and the amount is insufficient, repeat the process to make up the initial amount, adjust the pH~2.5 (the selected experimental flow is shown in Figure 4)

Condition: Each starting ore is 100g, repeated flotation and the amount is insufficient, repeat the process to make up the initial amount, adjust the pH~2.5 (the selected experimental flow is shown in Figure 5)

(Example 1)

Referring to Fig. 6, the waste cutting oil is filtered through the plate frame, and 120 g of the drained sludge is taken out, and the oil content is 13%, (dry basis) strontium carbide content is 61%, 矽 39%, and scrubbed at 1500 rpm for 5 minutes. The agglomerated particles formed by extrusion are fully unwrapped, and the slurry is adjusted to the flotation state for flotation conditions: slurry concentration 20%, kerosene 0.2 ml/100 g ore, hydrofluoric acid 2 ml/100 g ore, turpentine 0.05 ml/100 g ore, Three times flotation selection was carried out at pH~2.4, and the float slurry was taken out by adding 200 ppm of coagulant and at pH <2.5, and dehydrated by suction filtration. After drying, the product was obtained, the grade was 98.5%, and the selected three times of the slurry was directly pumped. The mixture was dehydrated by filtration, and dried to obtain a niobium carbide product with a grade of 99.0%.

(Example 2)

Referring to Figure 7, the waste cutting oil sludge is dried by 105 degree hot air for 24 hr, and 100 g of dry sludge powder is taken out, the oil content is <0.1%, the strontium carbide content is 55%, 矽45%, and the rinsing treatment is performed at 1500 rpm for 10 minutes. The sludge particles and the particles are fully rubbed to wipe off the oil on the surface of the particles, and after the surface of the particles is exposed, the slurry is adjusted to a flotation state to float conditions: slurry concentration 20%, kerosene 0.2 ml/100 g ore, Hydrofluoric acid 2ml/100g ore, turpentine 0.05ml/100g ore, pH~2.4, etc., three times flotation selection, take out the floating slurry through the addition of coagulant 200ppm and at pH2.3, use The mixture was dehydrated by suction filtration, and the product was obtained after drying, and the grade was 99.1%. The selected three times of the slurry was directly subjected to air filtration and dehydration, and after drying, the product of niobium carbide was obtained, and the grade was 98.9%.

In view of the above, the present invention has achieved the intended use and efficacy, and is more desirable and practical than the prior art, but the above embodiments are only specifically described for the preferred embodiment of the present invention. The present invention is not intended to limit the scope of the invention, and all other equivalents and modifications may be included in the scope of the invention covered by the invention.

Figure 1 is a flow chart showing the full-scale resource processing technology of the waste cutting oil of the present invention.

Figure 2A shows a SEM photo of ruthenium carbide.

Figure 2B shows a photograph of the dry residue of the waste cutting oil (the surface-attached particles are ruthenium).

Figure 3A shows the grade of tantalum carbide for the sinking of the flotation conditions (scrubbing time).

Figure 3B shows the grade of tantalum carbide as a sinking condition for flotation conditions (slurry concentration).

Figure 3C shows the grade of tantalum carbide as a sinking condition for flotation conditions (kerosene dosage).

Figure 3D shows the grade of tantalum carbide for the sinking condition of the flotation condition (adjusted dose).

Figure 4 is a schematic flow chart of the multiple selection experiments of the sedimentation of the present invention.

Figure 5 is a schematic flow chart showing the multiple selection experiments of the floating ore in the present invention.

Figure 6 is a schematic diagram showing the experimental flow of the first embodiment of the present invention.

Figure 7 is a schematic diagram showing the experimental flow of the second embodiment of the present invention.

Claims (7)

A full-scale resource treatment technology for waste cutting oil, the waste cutting oil is separated by solid-liquid separation, the oil is separated from the sludge, the oil can be reduced to secondary industrial utilization, or the incineration is used to recover the calorific value, and the sludge is treated by flotation The product is taken out from the floating ore and the product is taken out from the ore deposit, which can be used as a ceramic raw material or secondary use for the original purpose. The full-scale resource treatment technology of the waste cutting oil according to the first aspect of the invention, wherein the solid-liquid separation is for the purpose of taking out sludge having an oil content of 30% or less, and avoiding excessive oil hindering the floating of the tantalum carbide and the crucible. Separation and separation can be carried out by static precipitation, pressure filtration and heat drying. The full-scale resource processing technology of the waste cutting oil according to the first aspect of the invention, wherein the flotation treatment comprises sequential processing steps such as scrubbing treatment, slurry adjustment, and multiple selection. The full-scale resource processing technology of the waste cutting oil according to claim 3, wherein the scrubbing treatment is to put the sludge into the scrubbing tank, and add a small amount of water to the scrubbing blade to work at a height, and scrub at a high speed. To fully rub the sludge particles and particles, this effect can wipe the oil on the surface of the particles, expose the surface of the particles to react with the flotation reagent, and scrub at 1500 rpm for at least 5 minutes. The full-scale resource treatment technology of the waste cutting oil according to the third aspect of the patent application, wherein the slurry adjustment is to sequentially add the scrubbed slurry to the adjusting agent, the collector kerosene, the foaming agent, and the water. The surface of the cerium particles is reacted with the adjusting agent to strengthen the surface hydrophobicity, which is beneficial to the kerosene collector, and the adjusting agent is used to control the pH value of the slurry to 2-3, which is favorable for the condensed sedimentation of the cerium carbide, and the adjusting agent may be a mixture of hydrofluoric acid or hydrochloric acid. The acid is added in an appropriate amount to adjust the pH. The amount of kerosene added is preferably 0.2 ml/100 g ore. The amount of water added depends on the concentration of the slurry, and the concentration of the slurry is preferably 10-30%. For example, the full-scale resource treatment technology of the waste cutting oil described in claim 3, wherein the plurality of selections are flotation or sedimentation after flotation, and are separately put into the flotation tank to re-adjust the slurry to make the slurry. To achieve the above-mentioned better conditions, re-flotation, the use of multiple selections can gradually improve the grade, the floating ore can obtain better products after three selections, the grade of 98.5-99%, the sinking can be better after three selections. The product, tantalum carbide grade 98-99%. The full-scale resource treatment technology of the waste cutting oil according to the sixth aspect of the patent application, wherein the plurality of selected slurry waters containing the flotation operation have a flotation agent, and the floating pulp or the sediment slurry is dehydrated and can be recycled. Water use, saving chemicals and water. The particles of floating pulp are only a few micrometers, which is relatively difficult to filter. It can control the better dehydration conditions. It can be mixed with PVA (polyvinyl alcohol) more than 200ppm for coagulation under pH 2-3, which is beneficial to its use. Filtration dewatering operation efficiency, the particle size of the slurry is about ten micron, the flotation condition is suitable for its coagulation, and it can directly filter and dehydrate.