JPS58223473A - Treatment for regenerating waste liquid of aqueous lubricating and release agent - Google Patents

Abstract

PURPOSE:To enable the conservation and recycling of graphite, by separating oils from the waste liquid separated from the waste liquid of aq. lubricating and release agents by allowing the same to stand still, and passing the waste liquid through a filter of 1-10mu and adding an alkaline material to control the pH to 8.0-11.0. CONSTITUTION:The waste liquid mixed therein with the graphite-contg. lubricating and release agents which are used in a die casting machine in a stage for forging the melt of nonferrous metals and are unstuck on dies, etc. as well as working fluid, etc. is stored temporarily in a tank 1 and are removed of extraneous materials. Fine particulate oils are removed in an oil-water separator 2 of a gravity sepn. method, and fine particles such as swarf, dust, flocs of graphite, etc. are removed with the filtration treatment using a bobbinlike filter element 3 of 1-10mu. The filtrate is controlled to an aq. alkali soln. of 8.0- 11.0pH with the alkaline material such as ammoniac water or caustic alkali added thereto from a pH control chamber 4, whereby regenerated liquid 5 is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a graphite-containing lubricant mold release device used for the front mold of a die casting machine and for lubricating the plunger and tip in the molten metal forging manufacturing process of non-ferrous metals such as copper and aluminum. The present invention relates to a method for regenerating chemical waste liquid.

In recent years, Japan's die-casting industry has grown significantly, and at the same time, there have been remarkable technological advances.

However, on the other hand, labor costs, equipment costs, materials, molds, and other expenses have skyrocketed due to changes in parts costs, resulting in a dramatic increase in cost pressure.Furthermore, there have been problems with the working environment in the factory and pollution such as waste liquid treatment, smoke, and odors. has come to be seen as a problem.

In particular, compared to oil-based mold release agents, graphite-containing water-based lubricating mold release agents can maintain the mold temperature at a lower temperature, easily form a dry film, do not generate gas, and reduce defects such as blisters on the surface of castings. However, due to the increase in cost and the inclusion of ultrafine graphite particles, the degree of contamination of the die-casting machine is increased, the working environment is deteriorated, and the problem of disposing of mold release agent waste liquid has been highlighted.

One of the most important issues regarding waste liquid treatment is the treatment of oil and other waste liquids.
i.e., suspended solid particles), in order to ensure that they are disposed of with the transparency treatment index below the regulatory value, they cannot be allowed to flow directly into the final comprehensive wastewater treatment plant, and must be subjected to subsequent treatment (pretreatment). The current situation is that it is treated by applying

By the way, waste liquid regeneration treatment technology is still at the experimental stage, that is, there are attempts to regenerate it using existing oil/water treatment equipment and filtration treatment equipment, but none of them have been developed with enough regenerated liquid to meet the target water quality and physical properties. In reality, the spray nozzle becomes clogged and the storage stability deteriorates, especially when a regenerated liquid is used, so that it has not been put into practical use.

An object of the present invention is to provide a method for regenerating aqueous lubricant mold release agent waste that can be used in practical use in order to solve the problem of waste liquid treatment of aqueous lubricant mold release agents. The regenerated liquid is reused as a lubricating mold release agent, but in order to put this regeneration treatment method into practical use, the present invention specifically includes (a)
The components of the lubricating mold release agent, such as graphite particles, dispersant, and rust preventive agent, should remain in the treatment liquid as they are. A reprocessing method that provides properties such as no generation, especially covering the spray gun or spray nozzle with something that will not clog it, and (3) preventing corrosion or rust from forming on the mold, cavity surface, or surrounding machinery. The purpose is to provide the following.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for regenerating aqueous lubricant mold release agent waste according to the present invention will be explained below with reference to the drawings.

FIG. 1 shows the method of the present invention at 70-C[-, but as shown in the figure, the method of the present invention is
I In the lj method for regeneration of mold release agent waste, C is mag' copper,
Temporary tank 1 is used to store the waste liquid, which is a mixture of unattached graphite-containing lubricating mold release agent liquid used in die-casting machines in the manufacturing process of molten metal forging of non-ferrous metals such as aluminum, hydraulic oil, chips, dust, etc. Contaminants such as coarse dust, chips, oil, etc. are removed by allowing them to stand still for 1 iSII in advance.

Next, particulate oil is removed by an oil/water separator 2 using a gravity separation method, and particulates such as chips, dust, and graphite aggregates are removed by filtration using a thread-shaped filter element 3 of 1 to 10 μm. Then, the filtered liquid is adjusted to an alkaline aqueous solution having a pH of 8.0 to 11.0 by adding ammonia water or an alkaline substance such as caustic alkali from the P)-1 adjustment chamber 4 to obtain a regenerated liquid 5. In addition, in FIG. 1, 6 is a floating oil tank, and 7 is a relay bit.

The regenerating liquid obtained in this way removes impurities but leaves the graphite fine particles contained, and does not cause corrosion or rust on alkaline earth molds and cavity surfaces, and can be used again with lubricating mold release agents. It can be used effectively and achieves the intended purpose.

Next, a preferred embodiment of the method of the present invention will be described. An example will be described in which the recycling treatment of waste liquid stored in the pit of a die-casting machine during the aluminum wheel manufacturing process was studied. The properties of the waste liquid are as shown in Table 1.

Here, PH(hydrogen+'on1llllJj> :JISKO
COD (Chemical Oxygen Demand) by 102: Same as above SS (Suspended solids): Same as above Oil content - Same as above Solid content: Same as above Pump the waste liquid in Table 1 above from the pit into a 1,000 β tank. The mixture was allowed to stand still for about 20 hours, and impurities were left standing to be separated and oil and water were separated. (As a result, an oil film of 1 to 2 mm thick was formed on the oil surface, some precipitates such as chips were formed on the bottom of the tank, and a black-gray aqueous solution was obtained as the intermediate layer. The properties of the intermediate layer are shown in Table 2. Shown below.

Table 2 According to the properties of the intermediate layer liquid, the intermediate layer liquid of The properties are shown in Table 3.

Table 3 Properties of the dM filtrate Appearance: A large amount of suspended matter was observed in the 10μ treatment, but no such particles were observed in the other treatments, and a black-gray aqueous solution equivalent to that of a wafer was obtained.

Next, for each filtrate, add UP8 to ammonia water.
Prepare samples adjusted to 9.2 and unadjusted samples to evaluate storage stability.

The change in P H over time was as shown in FIG. 2 η, and the unadjusted solution (indicated by a solid line B with black circles in the figure) showed a rapid decrease in P l-1. As for the appearance, the agglomeration phenomenon of graphite fine particles was observed after 20 minutes (both of them sludged out), and when left for 4 months, most of the graphite fine particles flocculated and a black supernatant liquid and black precipitate were obtained. Furthermore, microorganisms (bacteria) such as Daphnia were confirmed in the supernatant using an electron microscope.

On the other hand, the PH adjustment line filtrate liquid (indicated by the solid line △ with white circles in the figure) produced some floating matter, but the extent was not different from the case where the fresh liquid was left. .

Results of a comparison of the properties and physical properties of Soshi-C Dokuni 5 μ filtration PI-1 adjustment solution (hereinafter referred to as regenerated solution) and a 50-fold diluted solution of a new liquid mold release agent commercially available under the name Hitazol GA142B. are shown in Table 4.

Table 4 Properties of reclaimed liquid and new liquid mold release agent, Physical property comparison table (Note) Items marked with * indicate the percentage of solid content.

From Table 4, it is considered that the regenerating solution produced by this reprocessing method can be used as a mold release agent after being adjusted to a predetermined concentration (1).Therefore, an experiment was conducted to use it in an actual manufacturing process.

The results showed that the mold release agent Spray Can J5 and the nozzle could be used normally without any clogging problems, and that the product was free from water wrinkles, discoloration, burning, dents, and
It was confirmed that the product could be used satisfactorily without any defective products such as irritation.

As described above, when using the method for regenerating aqueous lubricant mold release agent waste liquid of the present invention, various effects shown below can be obtained.

First, since the regenerated liquid can now be used again as a preforming agent, the problem of waste liquid disposal can be solved.

In addition, it has become possible to save and recycle graphite resources, making it possible to significantly improve the price. In addition, purchase price of mold release agent is 50%
The waste treatment process and costs are reduced by 80%.

Here C1 Regeneration Department] II! The facility does not require special chemicals or equipment and can be easily implemented, and can provide a practical regeneration treatment method.

In addition, the properties of the regenerated liquid, especially the dispersion stability, have been greatly improved, and the effect of uniform adhesion to molds, etc., has been achieved.
~ It can also contribute to improving product quality.

[Brief explanation of drawings]

FIG. 1 is a system diagram of the method of the present invention, and FIG. 2 is a characteristic diagram showing the change in pH of the filtrate over time when the pH-adjusted solution A and unadjusted solution B are left standing. 1...Static separation tank 2...Oil/water separator 3...Spindle filter 4... PH regulator

Claims (1)

[Claims] (1) A step in which the aqueous side WjIwi type agent waste liquid is stored in a separation tank and impurities are separated by standing, a step in which the oil content is removed from the stationary separated waste liquid in an oil-water separator, and the waste liquid from which the oil content has been separated is A water-based DJ lubricant consisting of a step of removing fine particles by passing it through a 1-10μ filter, and a step of adding an alkaline substance to the waste liquid from which the fine particles have been removed to adjust the pH to 8.0-11.0. Molding agent waste liquid raw treatment method.