TWI490173B - Method for recovering waste silicon waste from cutting oil - Google Patents

Description

Method for recovering waste mud resources from cutting oil

The invention relates to a method for recovering waste resources, in particular to a method for recovering tantalum carbide, sodium citrate and cutting oil from waste mud containing cutting oil.

The manufacturing process of the germanium wafer includes the steps of initial crystal growth, grinding, polishing, cleaning and slicing, and the waste mud is mainly from the slicing process. At present, the main technology of wafer slicing is multi-wire wire saw cutting technology. This technology mainly uses a metal cutting line (containing copper and iron) and an oily slurry mixed with tantalum carbide and cutting oil to cut the crystal rod, which can be used to take away the heat generated during the cutting process, and The chip crumb that is cut off is taken away. The material containing tantalum carbide, cutting oil, crucible chip crumb and a small amount of copper and iron impurities is a waste mud containing cutting oil.

At present, the industry is responsible for the recovery of resources containing cutting oil waste mud, among which the separation method of cutting oil and solid (containing strontium component + strontium carbide + small amount of copper, iron impurities) mainly includes:

1. Filtration method: It is carried out by solid-liquid separation technology, and most of the solid-liquid separation technology uses pressure filtration technology (using pressure filtration).

2. Distillation method, heating oily waste mud to the cutting oil to evaporate, and obtaining oil-free mud, cooling the gasification cutting oil, and recovering the cutting oil.

3. Pervaporation method: When the solution is diffused to the filter membrane, the filtrate is evaporated to achieve the purpose of solid-liquid separation.

Further, the separation method of the antimony component and the niobium carbide is mainly as follows:

1. Gravity method: using the difference between the density of tantalum and tantalum carbide to form different sedimentation speeds According to the sedimentation speed of the two, the recycling method is designed.

2. Flotation method: The crucible itself has hydrophobicity or enhances hydrophobicity by the action of flotation agent, so that the crucible can be aggregated at the liquid-gas or water-oil interface to collect and recover.

3. Electrophoresis method: Analytical method for separating the cation or anion with different amounts of charge in the solution and moving to the electrode at different migration speeds in an applied electric field.

4. Solvent extraction method: The separation force is carried out by utilizing the force of the hydrophobic and hydrophobic nature of the powder surface and the electrostatic force of the gravity and particle interface.

In the above filtration process, it is often found that for the oily waste mud, since the particle size of the solid component of the solid waste containing the cutting oil is very small (0.4 μm to 8 μm), during the filtration process, The components are easily stuck on the filter cloth, which causes blocking and filtration difficulties, and makes the subsequent filtration effect poor. Further, the powder solid obtained by pressure filtration and containing cerium carbide and cerium is difficult to separate due to the small particle size, so that it cannot be recycled.

In addition, the related prior art, such as the Taiwan patent application number: 099118261, is mainly for the recovery and purification of tantalum carbide powder, the steps of which are to initially filter and heat the mortar containing mortar. To remove the residual liquid; then, it is placed in an alkaline solution, and the alkali solution is used to dissolve the cerium in the cerium carbide/cerium mixture; after the lye is removed, the purified cerium carbide is obtained. However, this prior art is mainly directed to the powder purification study of tantalum carbide, and no further technical presentation for the recovery of the cutting oil has been found.

Another Taiwan patent application number: 099118266, mainly using filtration and heating to remove the mortar containing mortar to remove the liquid, and then adding the carbonized ruthenium / ruthenium mixture to a liquid medium, stirring and standing, to obtain a precipitated carbonized ruthenium / ruthenium mixture and suspension A liquid medium having a hydrazine, which is obtained by purifying a liquid medium suspended in hydrazine to obtain bismuth powder; another method for recovering hydrazine Therefore, the carbonized ruthenium/ruthenium mixture after removing the residual liquid is solid-liquid separated and placed in a liquid alkaline solution to obtain an alkaline solution in which ruthenium is dissolved, and a ruthenium-containing product is prepared from the alkaline solution. Further technical presentations of recovered cutting oil have not been found by this prior art.

Another Taiwan patent application number: 096112970, which mainly uses acid washing to remove metal substances in the mud, and then separates the barium from the barium carbide at a high temperature to recover the crucible therein. In the recycling process, only the mash in the mud is recovered, and no carbonized bismuth and waste liquid are recovered.

Another Taiwan patent application number: 098115605, this patent uses the particle phase transfer method, that is, through multiple steps of standing, centrifuging and drying to obtain tantalum powder. This patent utilizes a particle phase transfer method in which the settling speed depends on the speed of the centrifuge, which can be time consuming and energy intensive if recovered in large quantities.

Another Taiwan patent application number: 095150091, the main steps are first washed with acetone and centrifuged, added with pickling agent to remove iron, then washed with pure water and acetone and then washed once and dried, and then added specific gravity between 矽 and carbonization The flotation agent between the crucibles is dried by centrifugation to obtain a crucible. The recycling project is only flawed and cannot achieve the purpose of full recycling.

Another Taiwan patent application number: 099133041, the main object of which is the cutting oil in the cutting slurry, the flow is that the cutting slurry is placed in an oxygen-poor state, the temperature is 150~350 °C until the cutting oil and gas, the The gasification cutting oil is collected and cooled, and a cutting oil for cutting the slurry is obtained. The main object of the recovery is the cutting oil in the cutting slurry, which may deteriorate after being heated at a high temperature, resulting in failure to recover.

In view of the problems of the prior art, especially the filtration method, the object of the present invention is to provide a method for recovering tantalum carbide, sodium citrate and cutting oil from waste mud containing cutting oil, and providing a method for solving waste containing cutting oil. In the mud filtration process, the particles are too It is so small that the cutting oil is not easily filtered and the solids containing tantalum carbide after filtration are difficult to separate and recover. To this end, according to the object of the present invention, the inventors set a method for recovering waste mud resources containing cutting oil, the steps of which at least include: 1. mixing the waste oil containing the cutting oil uniformly; 2. scraping the cutting oil Adding sodium hydroxide to the mud, so that the cutting oil contains waste mud: the volume ratio of sodium hydroxide is 1:1 to 1:10 mixed and oscillated, and the sodium hydroxide is used in the waste oil containing the cutting oil. Dissolved into a sodium citrate solution for easy passage through the sieve; to form a solid solution containing a sodium citrate solution, containing barium carbide and a cutting oil; 3. passing the sodium citrate solution and cutting oil through the filter; And the carbonized ruthenium is filtered outside the mesh to obtain the solid containing cerium carbide; 4. The filtered sodium citrate solution and the cutting oil are allowed to stand, because the two are not mutually soluble and the specific gravity is poor, and the upper layer is The cutting oil with calorific value, the lower layer is sodium citrate solution; 5. The crystallization of the lower layer of sodium citrate solution at 70 ° C ~ 90 ° C to obtain sodium citrate solid; by the method of the invention, the steps can be greatly reduced Processing time and drug consumption, and using the cutting oil to waste mud before filtration Sodium hydroxide, which dissolves the bismuth component in the waste oil containing cutting oil by sodium hydroxide to form a sodium citrate solution, which can be easily passed through the filter screen to reduce the subsequent filtration operation, and the 矽 component for the filter card It is difficult to block and filter the resistance. And effective recovery of tantalum carbide, sodium citrate and cutting oil. Moreover, by using the method of the invention, in addition to avoiding the discarding of the waste oil containing the cutting oil and causing harm to the human body and the environment, the effect of the sustainable circulation of the valuable resources contained therein can also be achieved.

The first figure is a flow chart of the steps of the implementation of the present invention.

The second figure is the appearance of the waste oil containing cutting oil used in the present invention.

The third figure is the appearance of the cutting oil obtained by the method of the present invention.

The fourth figure is the appearance of sodium citrate obtained by the method of the present invention.

The fifth figure is the appearance of niobium carbide obtained by the method of the present invention.

The technical content, features and embodiments of the present invention will be described below with the aid of the drawings, so that you can have a better understanding of the case.

Please refer to the first figure, which is a flow chart of the steps of the method for recovering waste oil resources of cutting oil of the present invention.

In the first figure, the method of the present invention may comprise the following steps:

Step 1: Mix the waste oil containing cutting oil evenly (the appearance is as shown in the second figure).

Step 2: Adding the cutting oil waste mud to the sodium hydroxide of 1N~6N concentration, so that the cutting oil waste sludge: sodium hydroxide volume ratio is 1:1 to 1:0 mixed, then ultrasonic vibration 1-4hr, by using the sodium hydroxide to dissolve the cerium component in the cutting oil waste mud to form a sodium citrate solution, which can be easily passed through the sieve; so as to form a mixed sodium citrate solution containing strontium carbide Solid and cutting oil;

Step 3: filtering, passing the sodium citrate solution and the cutting oil through the sieve; and filtering the carbonized ruthenium outside the mesh to obtain the solid containing the cerium carbide;

Step 4: The filtered sodium citrate solution and the cutting oil are allowed to stand, because the two are not mutually soluble and the specific gravity is poor, and the stratification is carried out. The upper layer is the cutting oil with calorific value (as shown in the third figure), and the lower layer is sodium citrate. Solution. The upper cutting oil can be used as an auxiliary fuel.

Step 5: The lower sodium citrate solution is subjected to crystallization at 70 ° C to 90 ° C for 1-4 hr to obtain a sodium citrate solid (as shown in the fourth figure).

In addition, in the present invention, the solid solution containing barium carbide can be added with 1N~6N sulfuric acid and 30% hydrogen peroxide, so that the solid containing barium carbide: 1N~6N concentration sulfuric acid: 30% The ratio of hydrogen peroxide is 1 (g): 10 (ml): 0.02 (ml), and then allowed to stand for 1-4 hr, thereby dissolving to remove copper and iron impurity solids, thereby obtaining high-purity carbonized ruthenium (such as the fifth). Figure). The high-purity niobium carbide may still have a small amount of antimony component. In the preferred embodiment of the present invention, the high-purity niobium carbide may be further added with sodium hydroxide to dissolve the niobium component therein to obtain more Purified tantalum carbide solid. By analogy, the number of times of purification can be further limited.

In summary, the present invention is indeed in line with industrial utilization, and is not found in publications or publicly used before application, nor is it known to the public, and has non-obvious knowledge, conforms to patentable requirements, and patents are filed according to law. . However, the above description is a preferred embodiment of the industry of the present invention, and all the equivalent changes made by the scope of the patent application of the present invention are within the scope of the claim.

Claims (2)

A method for recovering waste mud resources of cutting oil, the steps comprising at least: 1. mixing the waste oil containing the cutting oil uniformly; 2. adding the waste oil containing the cutting oil to the sodium hydroxide, and depleting the cutting oil. Mud: the volume ratio of sodium hydroxide is 1:1 to 1:10 mixing and oscillating, and the oscillation is for ultrasonic oscillating 1-4h, and the cerium component in the cutting oil waste mud is dissolved by the sodium hydroxide; Forming a solid solution of sodium citrate mixed with barium carbide and cutting oil; wherein the concentration of the sodium hydroxide is 1N~6N; 3. passing the sodium citrate solution and the cutting oil through the filter; Obtaining the solid containing carbonized ruthenium outside the net; 4. The filtered sodium citrate solution and the cutting oil are allowed to stand, because the two are not mutually soluble and the specific gravity is poor, and the upper layer is the cutting oil with calorific value. The lower layer is a sodium citrate solution; 5. The lower layer of sodium citrate solution is crystallized at 70 ° C to 90 ° C to obtain a sodium citrate solid. For the method for recovering the waste oil containing cutting oil according to the first aspect of the patent application, the solid containing the niobium carbide in the step 3 is added with 1% to 6N sulfuric acid and 30% hydrogen peroxide. Solid containing cerium carbide: 1N~6N concentration sulfuric acid: 30% hydrogen peroxide ratio is 1 (g): 10 (ml): 0.02 (ml), thereby dissolving and removing copper and iron impurity solids to obtain high purity Carbide.