JP5112134B2 - Waste car shredder dust as fuel for cement firing - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for converting waste automobile shredder dust into a cement firing fuel, and in particular, waste automobile shredder dust cement that does not adversely affect the cement manufacturing process and product cement quality while introducing the waste automobile shredder dust into the cement firing process. The present invention relates to a method for making fuel for firing.

After removing the parts that can be used for repairing other cars or parts that may cause problems in disposal from the scrapped scrapped car, the scrapped car is crushed, and valuables such as metal are separated by means of separation. The crushing residue after collection | recovery is called an abandoned automobile shredder dust (ASR: Automobile Shredder Residue).

This waste car shredder dust is mainly composed of combustible materials such as plastic, rubber and sponge, and inorganic materials such as glass, but it is disposed of in landfills because it contains trace amounts of harmful metals such as heavy metals and organic solvents. In some cases, it is necessary to use a managed disposal site. In recent years, the disposal cost tends to increase with the tightness of the disposal site, and a recycling method that can effectively use the calorific value of the combustibles in the scrapped car dust has been demanded.

From this point of view, Patent Document 1 discloses a method for producing cement from a shredder dust of a discarded vehicle as a cement clinker raw material.

JP-A-9-86977

However, there are various components in scrap car shredder dust, and some of them are not preferable to be contained in cement. Therefore, the actual situation is that the waste car shredder dust has not been used as a raw material for cement.

However, due to the recent increase in resource prices, etc., the separation process has become thorough and tends to reduce chlorine, metals, etc., which are representative of components that are not preferably contained in the cement. Yes, there is a possibility that scrap car shredder dust can be used as cement raw fuel. In particular, due to the rising price of fossil fuels such as coal, which is a fuel for burning cement, there is a situation where there is an expectation for use as a substitute fuel for fossil fuels for scrapped car shredder dust. Therefore, the present inventors are able to use the existing scrap car shredder dust as a cement raw fuel that has not been used at all, because it is a high-temperature process. As a result of pursuing whether it can be used effectively for cement firing fuels that require a certain amount of heat generation and can prevent adverse effects on cement quality, cement manufacturing processes, etc. It came to find the method of making dust cement fuel.

As a result of earnestly pursuing the above-mentioned problems, the present inventors have found that waste car shredder dust contains a large amount of inorganic substances such as crushed glass in fine particles, has a low calorific value, and has many components such as alkali. The present inventors have found that by controlling the fine particle content to a certain level or less, it is possible to suitably use scrap car shredder dust as a cement firing fuel.

That is, the present invention includes the following [1] to [6].
[1] A sample of waste automobile shredder dust is dried at 105 ° C. to determine the amount of water, followed by sieving using a 19 mm sieve, and then fine particles under the 19 mm sieve are sieved using a 5 mm sieve. min to, on 19mm sieve to the total mass after drying, 5～19Mm, calculated mass ratio of each particle group under 5mm sieve, if 5mm undersize mass ratio of the sample is less than 30% waste Car shredder dust is introduced into the cement firing process as it is, and when the 5mm under-screen mass ratio of the sample is more than 30%, the waste car shredder dust is sieved so that the 5mm under-screen mass ratio is 30% or less A method for converting waste car shredder dust into a cement firing fuel, characterized by being introduced into a cement firing step .
[2] The waste car shredder dust has a total calorific value of 4,500 kcal / kg or more and a chlorine content of 3.0% by mass or less. Fueling method.
[3] A scrapped automobile shredder according to [1] or [2], wherein a part of combustion gas is extracted from a kiln exhaust gas passage from a kiln bottom of a rotary kiln in the cement firing step to a bottom cyclone A method for converting dust into a cement firing fuel.
[4] The waste car shredder dust as a fuel for cement firing of the waste car shredder dust according to any one of [1] to [3], wherein the waste car shredder dust is introduced into the kiln bottom of a rotary kiln. Method.
[5] The scrapped automobile according to any one of [1] to [4], wherein the shredder dust is extracted from the storage facility before being introduced into the cement firing step by an extractor having a crushing function. A method of converting shredder dust into a cement firing fuel.
[6] The waste car shredder dust according to any one of [1] to [5], wherein the waste car shredder dust is introduced into the cement firing process at an input amount of 1.5 kg or more per 1 ton of cement production. Cement firing fuel conversion method.

According to the above-described fuel conversion method for waste automobile shredder dust according to the present invention, waste automobile shredder dust can be effectively used as an alternative fuel for fossil fuel for cement firing, and to cement quality, cement manufacturing process, and the like. Can prevent adverse effects.

In the following, an embodiment of a method for converting a waste car shredder dust (hereinafter, abbreviated car shredder dust may be abbreviated as ASR) into a cement firing fuel according to the present invention will be described.

ASR in relation to the present invention refers to a scrapped automobile after removing parts that can be used for repair of other cars and parts that may cause problems in disposal and then removing the body of the scrapped car. This refers to the crushing residue that remains after crushing to a maximum diameter of about 100 mm using a crusher and further recovering valuable materials such as metals by sorting means such as magnetic sorting, wind sorting, and manual sorting.

This ASR is mainly composed of combustible organic substances such as plastics, rubbers, sponges (urethanes), etc., and inorganic substances such as glasses and uncollected metals. If you look at it, it is a mixture of substances in various forms such as fibrous, debris, fine particles, etc., but it is macroscopic to use several hundred kg per hour as used as a fuel for cement firing. From a general point of view, it can be regarded as a substantially uniform mixture. As described above, since ASR contains a large amount of combustibles, it has a total calorific value of around 5,000 kcal / kg and can be suitably used as an alternative fuel such as cement firing fuel.

In the fueling method for cement firing according to the present invention, waste automobile shredder dust having a 5 mm sieve mass ratio of 30% or less is introduced into the cement firing step. Here, the mass ratio under 5 mm is based on the dry matter and is determined by the following method. First, the ASR sample is dried at 105 ° C., and the water content is determined. Subsequently, sieving is performed using a 19 mm sieve. The top of the 19 mm sieve is large or long plastic, rubber, sponge (urethane), or metal. Next, the fine particles under the 19 mm sieve are sieved using a 5 mm sieve. Then, the mass ratio of each particle group on the 19 mm sieve, 5 to 19 mm (hereinafter referred to as 5 mm sieve) and 5 mm sieve on the total mass after drying is obtained.

In the fine particles under the 5 mm sieve, there are many crushed glass and the like, and since there are many SiO ₂ and Na ₂ O as components, the calorific value is low. Therefore, ASR with a large amount of fine particles under a 5 mm sieve is not preferable as an alternative fuel.

In addition, when the alkali content such as Na ₂ O is increased, when it is incorporated as a cement component, an alkali aggregate reaction may be caused at the time of cement use, or the reaction at the initial stage of hydration may be affected. Often not preferred. Furthermore, the fine particles under the 5 mm sieve are rich in inorganic substances and have a large bulk specific gravity. On the other hand, the coarse particles on the 5 mm sieve and the 19 mm sieve have many organic substances with a small specific gravity. Becomes smaller. Therefore, ASR with a large amount of fine particles tends to have a large component fluctuation due to segregation of the fine particles and coarse particles during the transport process, the storage process, and the like. From these points, the use of ASR having a large amount of fine particles is not preferable.

For the reasons as described above, in the cement firing fuel conversion method of the present invention, ASR having a 5 mm under-sieving mass ratio of 30% or less is introduced as an alternative fuel into the cement firing step. Since the value of the mass ratio under the 5 mm sieve is roughly determined by the processing facility for crushing and separating the used automobile, ASR can be introduced by selecting a processing facility whose value is 30% or less. Further, ASR having a 5 mm sieve mass ratio exceeding 30% can be further used as a 5 mm sieve mass ratio of 30% or less by sieving or the like.

As an alternative fuel for cement firing, the total calorific value of ASR is preferably not less than 4,500 kcal / kg. Below this value, the merits of using it as an alternative fuel are reduced in consideration of various costs associated with the use of ASR.

The chlorine content in the ASR is preferably 3.0% by mass or less. If the amount of chlorine brought in during the cement manufacturing process increases, there may be adverse effects on the cement quality, the coating in the cement firing process may increase, and troubles such as clogging may occur. In particular, the chlorine concentration in the product cement is specified as 350 ppm or less, and in order to clear this with sufficient margin, the amount of chlorine in other raw fuels is taken into account, and the ASR used as an alternative fuel It is desirable that the chlorine content is not more than the above numerical value.

The cement firing process using ASR as an alternative fuel preferably includes a so-called chlorine bypass system that extracts a part of the combustion gas from the kiln exhaust gas passage from the kiln bottom of the rotary kiln to the bottom cyclone. By providing this system, the amount of chlorine circulated between the rotary kiln and the preheater can be reduced, and it is possible to prevent the coating from increasing and causing troubles such as blockage. The bleed rate by the system is preferably 2% or more, and it is desirable to determine and determine the circulating chlorine amount.

ASR can be introduced into the cement firing process at the calcining furnace, rotary kiln bottom, before the kiln of the rotary kiln, etc., but ASR contains a relatively large crushed piece with a maximum diameter of about 100 mm, so it burns with a burner. In view of the difficulty, it is preferable to introduce the rotary kiln into the kiln bottom.

As mentioned above, ASR contains relatively large fragments and many fibrous ones, so they have entanglement properties, and when extracted from the storage facility before being introduced into the cement firing process, they are discharged as a nodule. , Tend not to be discharged smoothly. Therefore, it is preferable to perform extraction from the storage facility while loosening with an extractor having a crushing function. Specifically, extraction can be suitably performed using a rake feeder or the like.

As ASR has the property of being entangled as described above, considering that it is difficult to extract in a very small amount, and that the benefits as an alternative fuel should be obtained even when considering the costs associated with the use of ASR, It is preferable to introduce into the cement firing step with an input amount of 1.5 kg or more per ton of cement production.

As mentioned above, although embodiment of the fuel conversion method for cement burning of the waste car shredder dust which concerns on this invention was described, this invention is not limited to these description, The technical thought described in the claim It goes without saying that various changes and the like can be made within the range and the equivalent range.

1. Measurement of ASR properties A, B, C Three types of ASR samples generated from three waste car treatment facilities were dried by the method described above, and the total calorific value was measured (JIS
Z 7302-2). Further, sieving was performed, and the mass ratio of each particle group on the 19 mm sieve, on the 5 mm sieve, and on the 5 mm sieve was determined. Further, on 5mm sieve, for each particle group under 5mm sieve, it was determined by analyzing the content of SiO ₂ and Na ₂ O (X-ray fluorescence analysis). In this case, plastics, rubber, sponges, and metals picked up from the material on the actual 19 mm sieve by hand are combined and regarded as a particle group on the 19 mm sieve, and on the actual 19 mm sieve. The remainder of the substance is sifted with a 5 mm sieve together with the substance under the 19 mm sieve.
The obtained measured values are shown in Table 1.

From Table 1, it can be seen that Samples A and B having a low 5 mm sieve mass ratio of 30% or less have a high total calorific value of 4,500 kcal / kg or more and are preferable properties as an alternative fuel for cement firing. In addition, each sample has a high content of SiO ₂ and Na ₂ O under a 5 mm sieve, and it can be seen that this group of grains is an unfavorable component as an alternative fuel for cement firing.

2. ASR equivalent to A in Table 1 is 350 kg / h (amount of cement produced of 1 ton) Per 2.1 kg). The chlorine content of this ASR was 2.2% by mass, and extraction was performed at an extraction rate of 2.0% with the chlorine bypass system installed in the cement firing step.
The operation results were as follows.
-ASR effectively acted as an alternative fuel for cement firing, and the coal used in the cement firing process could be reduced by 0.25 t / h.
-The chlorine concentration in the manufactured cement had a margin up to the standard value of 350 ppm for the chlorine concentration, and there was no problem in terms of quality.
・ The adhesion of the coating to the pre-heater was observed, but no effect was observed. In addition, there was no adverse effect on the operating conditions of other cement firing processes.
・ In the ASR transport process and storage process, component fluctuations due to segregation of fine particles and coarse particles that were problematic were not observed.
-A rake feeder was installed in the extraction section from the ASR input hopper. As a result, the ASR forming the entangled baby nodules was extracted while loosening with a rake feeder, so that it could be extracted smoothly.

3. Summary As can be seen from the results of the above examples, waste car shredder dust having a 5 mm under-sieving mass ratio of 30% or less can be effectively used as an alternative to fossil fuels for cement burning, as well as cement quality and cement production. It is possible to prevent adverse effects on processes and the like.

Claims (6)

A sample of waste automobile shredder dust is dried at 105 ° C. to determine the amount of water, followed by sieving using a 19 mm sieve, and then sieving the fine particles under the 19 mm sieve using a 5 mm sieve. The mass ratio of each particle group on the 19 mm sieve, 5-19 mm, and 5 mm sieve with respect to the total mass after drying is obtained, and when the 5 mm sieve mass ratio of the sample is 30% or less , it is a scrapped car shredder dust. Is introduced into the cement firing process as it is, and when the 5 mm under sieve mass ratio of the sample exceeds 30%, the waste automobile shredder dust is sieved so that the 5 mm under sieve mass ratio is 30% or less, and then the cement firing is performed. A method of converting waste car shredder dust into a cement firing fuel characterized by being introduced into a process.   2. The method of converting waste car shredder dust into a cement firing fuel according to claim 1, wherein the waste car shredder dust has a total calorific value of 4,500 kcal / kg or more and a chlorine content of 3.0% by mass or less. .   The waste car shredder dust cement according to claim 1 or 2, wherein a part of the combustion gas is extracted from a kiln exhaust gas flow path from the bottom of the rotary kiln to the bottom cyclone in the cement firing step. Fueling method for firing.   The method for converting waste car shredder dust into a cement firing fuel according to claim 1, wherein the waste car shredder dust is introduced into the kiln bottom of a rotary kiln.   The waste vehicle shredder dust is extracted from the storage facility before being introduced into the cement firing step by an extractor having a crushing function. Cement firing fuel conversion method.   6. The waste car shredder dust for cement firing according to claim 1, wherein the waste car shredder dust is introduced into the cement firing process at an input amount of 1.5 kg or more per ton of cement production. Fueling method.