JP5289836B2 - Processing method of used antifreeze for aircraft and grinding aid using the processed antifreeze - Google Patents

Description

The present invention relates to a method for treating spent antifreeze for aircraft and a grinding aid using the treated antifreeze.

Anti-icing agents, deicing agents for aircraft, anti-freezing agents for runways, and snow melting agents are mainly composed of propylene glycol, and these sprayed compositions fall to parking lots and runways after spraying. In addition, it is necessary to decompose propylene glycol by a wastewater treatment mechanism such as an airport facility and discharge it to a river or the like. Conventionally, biodegradation treatment represented by activated sludge treatment is used by heating. On the other hand, as a waste liquid treatment of antifreeze for aircraft to be sprayed in large quantities, as proposed in Japanese Patent No. 280489 and Japanese Patent Laid-Open No. 7-166149, the glycol in the waste liquid is concentrated by a distillation process and water is used. Separated and reused. However, when the glycol is concentrated, the viscosity increases and the dispersibility when added to the material to be pulverized decreases and the pulverization efficiency decreases.
Patent No. 280489 JP-A-7-166159

In addition, all of the above methods are not suitable for industrialization because of their high processing costs. The object of the present invention is to solve the above-mentioned problems and to use propylene glycol as a main component, for example, anti-freezing agents such as aircraft anti-icing agents, deicing agents, runway anti-freezing agents, snow melting agents, etc. It is a method of efficiently treating with, a method of reducing the viscosity, and providing a method of effectively reusing as a grinding aid for cement clinker.

As a result of intensive studies, the present inventors have solved the above problems. That is, the present invention provides a first step of collecting the antifreeze for the distribution mainly composed of propylene glycol or collecting it as a waste antifreeze that is unused and adding a flocculant to the waste antifreeze to obtain polyacrylic acid in propylene glycol. Is a processing method for the antifreeze solution for spreading, comprising a second step of coagulating and precipitating, a third step of filtering the coagulated precipitate, and a fourth step of measuring the viscosity of the waste antifreeze solution after the filtering.

The first step includes a step of adjusting the propylene glycol concentration. In the second step, one or more of polyaluminum chloride, ferric chloride, and polyiron sulfate is used as a flocculant, and water is further added. It was added to the extent that the calcium oxide supersaturated maintained until pH4 or 11, which is the process how, characterized in that to coagulating sedimentation polyacrylic acid.

In the second step, it is further the process how characterized by adding a polymer flocculant and / or sand.

Furthermore, the above-mentioned treatment method is such that the viscosity is measured with a kinematic viscometer, and the measured value is 50 mm ² / s or less.

Further, the processing method in the treated cement material including spraying antifreeze or grinding aids for cement clinker, further a cement material or cement clinker pulverizng aids containing said processing antifreeze diethylene glycol.

Hereinafter, embodiments of the present invention will be described in detail. The method of using the antifreeze solution for distribution of the present invention is applicable to unused antifreeze solution for distribution, the remaining liquid in the tank of the distribution vehicle, and the waste solution after distribution. The antifreezing liquid for spreading means that the antifreezing liquid adheres to the cloth body by spreading and prevents the surface of the cloth body from freezing, or the snow falling on the surface of the cloth body is melted to prevent snow accumulation (anti It is used for the purpose of melting these snow and ice (deicing) by spreading on the surface of an object that has already been frozen or snow-covered. Examples of such agents include icing agents, deicing agents, antifreezing agents for runways, and snow melting agents. Such an antifreeze for spreading is composed mainly of propylene glycol, and a thickener for giving an appropriate viscosity (for example, polyacrylic acid, sodium polyacrylate, potassium polyacrylate, carboxymethylcellulose, xanthan gum, etc.) It contains a small amount of a rust preventive agent (for example, benzotriazole, thiabendazole, imidazole, etc.) added when an aircraft body is targeted. At this time, the anti-icing distribution antifreeze has a propylene glycol concentration of about 50%, and the deicing distribution antifreeze has a propylene glycol concentration of about 80%, which is diluted about 20 times.

When these antifreezing liquids are distributed on an aircraft body or a runway surface at an airport or the like, the snow and ice are melted, and the waste antifreeze diluted with the molten water flows into drainage facilities such as airport facilities.

The 1st process in this invention collect | recovers such an antifreeze for distribution after use as a waste antifreeze. The recovery method may be a conventional method and is not particularly limited. For example, in the case of an airport, for example, gently at the lower part of the aircraft that is the target of antifreeze distribution, that is, on the road surface of the parking lot or on the side of the runway. It is possible to collect the waste antifreeze by a method such as installing a groove with a slope, allowing the waste antifreeze to flow into the groove, and consolidating the groove to introduce the waste antifreeze into a storage tank or reservoir. . In addition, the unused antifreeze for distribution and the remaining liquid in the tank of the distribution vehicle are collected from storage containers, tanks, etc. as the first step. The propylene glycol concentration can be easily measured with, for example, a pocket propylene glycol concentration meter PAL-88S (manufactured by Atago Co., Ltd.). The refractive index change of the propylene glycol-water system is measured by attaching the test solution to the prism. A concentration of 10% to 60% is desirable, preferably about 40%. If it is 10% or less, there is a disadvantage that the addition rate of the flocculant is increased, and if it exceeds 60%, polyacrylic acid may remain in the solution due to aggregation precipitation in the second step.

The second step in the present invention uses a flocculant such as polyaluminum chloride, ferric chloride, polyiron sulfate, and further adds calcium hydroxide to a degree of supersaturation and keeps it between pH 4 and 11, Acrylic acid is agglomerated and precipitated. Add 3 kg of calcium hydroxide to 3000 liters of anti-icing antifreeze solution containing about 60% water and adjust the pH to 6, and then add 300 liters of ferric chloride aqueous solution prepared to a concentration of 4000 ppm. Added. The mixed solution was stirred with a stirring blade, and the suspension was led to a sedimentation place and allowed to stand, whereby coagulation precipitation occurred. The aggregated precipitate was separated at the sedimentation site, and the supernatant was recovered.

In the former stage, the addition of a polymer flocculant and / or sand together with the flocculant can further accelerate the coagulation precipitation treatment of polyacrylic acid.

As the polymer flocculant, any of anionic polymer flocculants, nonionic polymer flocculants, cationic polymer flocculants, and amphoteric polymer flocculants can be used. Can be suitably used. Aclean F is an anionic polymer flocculant, and the main component is an acrylamide / acrylic acid copolymer.

Ferric chloride was added to the waste antifreeze, pH was adjusted with sodium hydroxide, and then a predetermined amount of Aclean F was added little by little, followed by stirring, and then silica sand was added with stirring. The sand depends on the colloidal species to be precipitated, but in the case of ferric chloride, No. 6 silica sand is preferred.

The kinematic viscosity of the supernatant was measured and found to be 4.4 mm ² / s. Canon Fenske backflow (SF) was used for the measurement of kinematic viscosity. In the procedure, a predetermined amount was put into a viscometer, a passage time between predetermined intervals in a flowing liquid capillary was measured, and converted into a kinematic viscosity by the following formula.
Kinematic viscosity (mm ² / s) = Kinematic viscosity constant (mm ² / s ² ) x Outflow time (s)
The kinematic viscosity constant is an eigenvalue determined by the standard sample by each viscometer.

Table 1 shows the kinematic viscosities of the supernatants obtained under various coagulation precipitation conditions.

In the experiment of Experiment No. 1, the waste propylene glycol is turbid, and a decrease in viscosity is seen with respect to the kinematic viscosity of 1200 mm ² / s or more indicated by the sample of Experiment No. 6 (blank: waste propylene glycol itself). The low kinematic viscosity was not reached until the subsequent treatment could be performed sufficiently.

On the other hand, the samples of Experiment Nos. 2, 3 and 4 showed kinematic viscosities almost equal to 4.4 which is the kinematic viscosity of the sample of Experimental Example 5 using a pure propylene glycol aqueous solution (50%).

The value of the kinematic viscosity after the treatment is preferably 50 mm ² / s in terms of handling such as pumping. Further, when it is 30 mm 2 / s or less, it is favorable as a grinding aid in terms of handling surface, mixing with cement, shortening of grinding time, and development of cement strength. In particular, when it is 5 mm ² / s or less, the above effect can be exhibited with a smaller amount.

Under the same conditions, 0.46% by volume of Aclean F for waste propylene glycol and 12.5 g of No. 6 silica sand for 1 liter of waste propylene glycol for the experiment level 3 flocculant Was added, and the rate of formation of the supernatant in the precipitate layer was measured. As a result, it took 3 hours for the supernatant to occupy 55% in the height direction. On the other hand, in experiment number 3, it was 22 hours.

The kinematic viscosity of the supernatant was 4.2 mm ² / s, which was slightly smaller than the experimental level 3.

Next, a cement clinker crushing experiment was performed using each of the above samples as a crushing aid.

The cement clinker fired in the cement kiln is pulverized together with gypsum in a finishing mill to become the final cement. Usually, a ball mill is used for this cement finishing grinding.

It is known that when grinding with a ball mill, the grinding efficiency of the material to be ground decreases due to the agglomeration of the ground fine particles and the cushioning effect caused by the fine particles adhering to the inner wall of the mill and the ball. ing.

In order to increase the grinding efficiency, various grinding aids are usually added during ball milling. In general, polar organic compounds such as alcohols, amines, organic acids, and aromatic compounds are known as substances having a grinding aid effect. Those that do not adversely affect the setting and strength development of the cement are preferred. Generally, diethylene glycol, ethylene glycol, triisopropanolamine or the like is used as a grinding aid in the cement clinker finishing grinding process. In the present invention, the above samples (Experiment Nos. 2, 3, and 4) can be used as an alternative to the cement finishing grinding aid.

Examples of the finish grinding mill that can be applied in the present invention include a tube mill and a roller mill in addition to the above-described ball mill.

The sample is desirably mixed in an amount of 0.01 to 1 part by mass, preferably 0.06 to 0.09 part by mass, and particularly preferably 0.03 to 0.05 part by mass with respect to 100 parts by mass of the cement clinker. If it is less than 0.01 part by mass, a sufficient grinding aid effect cannot be obtained, and if it exceeds 1 part by mass, the strength and setting quality of the obtained cement are adversely affected.

The above sample can be used alone, but can also be used in combination with other general grinding aids. Further, as the charging method, either the method of charging the sample and a general grinding aid or the like separately, or the method of charging a premixed material can be applied.

The type of cement clinker that can use the above sample as a grinding aid is not particularly limited, and normal, early strength, very early strength, moderate heat, low heat, and sulfate resistant portland cements specified in JIS R5210 “Portland Cement”. It is also applicable to cement clinker such as white cement and alumina cement. Furthermore, the present invention can be applied not only at the time of normal cement production, but also when a mixed cement is produced by simultaneously mixing mixed materials such as blast furnace slag and fly ash in a finishing mill.

EXAMPLES Hereinafter, although an Example is given and the content of this invention is demonstrated more concretely, this invention is not limited to the following Example.

(1) Waste antifreeze shown in Table 1 was used as a material grinding aid. For comparison, waste propylene glycol (experiment number 7) not subjected to a coagulation sedimentation treatment and a 50% aqueous solution of an industrial product of propylene glycol (experiment number 11) were also included.
The cement clinker was made by Taiheiyo Cement Co., and the gypsum used was drained dihydrate gypsum collected at a thermal power plant.

(2) Preparation and evaluation of cement Cement clinker was crushed by a 3 kg / batch ball mill. 3 kg of ordinary Portland cement clinker coarsely pulverized to 5 mm or less, and gypsum in an amount calculated so that the amount of SO _{3 of the} finished cement is 2.0% by mass are put into the above ball mill, and the target brain specific surface area is 3200. Cement was prepared by pulverizing to ± 100 cm ² / g. At this time, the grinding time (seconds) required to reach the target brain specific surface area was recorded. The amount of the sample added was 0.03, 0.06, and 0.09 parts by mass with respect to 100 parts by mass of the clinker. In Table 1 above, 0.06 parts by mass is shown as a representative.

As comparative examples, when the above sample was not added, and when 0.06 parts by mass of propylene glycol, which is generally used as a grinding aid, was added to 100 parts by mass of cement clinker, The clinker was crushed to prepare a cement.
The grinding efficiency was evaluated by grinding the cement clinker by the above grinding method. The grinding efficiency was determined by measuring the Blaine specific surface area value (B) according to JIS R5201 “Cement physical test method” and dividing the Blaine specific surface area value (B) by the time (T) required for crushing (B / T ) As the B / T value is larger, the pulverization per unit time proceeds and the pulverization efficiency is better. In addition, the quality of the obtained cement was confirmed. As for the quality confirmation items, a setting test and a strength test were conducted in accordance with JIS R5201 “Cement physical test method”. Table 2 shows the grinding efficiency (B / T) of the prepared cement, and Table 3 shows the quality test result of the prepared cement. The mortar compressive strength shows the result of 28 days.

As is apparent from Table 2, Experiment Nos. 8 to 10 in which the above sample was added and the cement clinker was pulverized were Experiment No. 7 in which only calcium hydroxide was added to the grinding aid, and neither pH adjustment nor coagulation precipitation treatment was performed. Compared with Experiment No. 12, the B / T value increased, and the pulverization aid effect of the waste liquid was confirmed. Moreover, the result equivalent to the experiment number 11 which added 0.03 mass part of propylene glycol which is an industrial product was obtained. As is clear from Table 3, the setting and compressive strength of the cements of run numbers 8 to 10 show the same results as those of experiment number 11, and thus the above sample can be used as an alternative to the grinding aid. It can be seen that it is.

In the agglomeration experiment of Experiment No. 3 in Table 1, the effect of the addition of the polymer flocculant and silica sand at the same time as that of Experiment No. 9 or better than this was obtained.

By carrying out the present invention, an antifreeze for spreading such as an anti-icing agent for aircraft, a deicing agent, an anti-freezing agent for a runway, a snow melting agent, etc. is cheaply and efficiently treated, its viscosity is reduced, It can be effectively reused as a grinding aid for cement clinker.

Claims (6)

A first step of recovering as a waste antifreeze after use of an antifreeze for distribution mainly composed of propylene glycol or unused;
A second step of adding a flocculant to the waste antifreeze and aggregating and precipitating polyacrylic acid in propylene glycol;
A third step of filtering out the aggregated precipitate;
A fourth step of measuring the viscosity of the waste antifreeze after the filtration;   The first step includes a step of adjusting the propylene glycol concentration, and in the second step, one or more of polyaluminum chloride, ferric chloride and polyiron sulfate is used as a flocculant, and further calcium hydroxide The method for treating the antifreeze solution for spreading according to claim 1, wherein the polyacrylic acid is coagulated and precipitated by adding to a degree of supersaturation and maintaining the pH between 4 and 11. Moreover, subjected to viscosity measurement in a kinematic viscometer, the measured value is, the processing method of spraying antifreeze according to claim 1 or 2, wherein the above processing method is not more than 50 mm ² / s. In the second step, a polymer flocculant and / or sand is further added. The method for treating an antifreeze for spreading according to any one of claims 1 to 3. The raw material for cement manufacture containing the antifreeze for distribution processed by the processing method in any one of Claims 1-4, or the grinding aid of a cement clinker. Moreover, it claims 5 feedstock of cement production described or, pulverizng aid for cement clinker containing diethylene glycol.