JPH03159939A - Equipment for producing ultrafine powder - Google Patents

Abstract

PURPOSE:To efficiently obtain ultrafine powder useful as a concrete admixture by combining ultrafine pulverization treatment equipment with ultrahigh-temperature vaporizing treatment equipment and product preparation equipment so as to perform specific action. CONSTITUTION:Ultrafine pulverization treatment equipment (A) is constructed of the first coal combustion ash receiving hopper 9, an ultrafine pulverizer 10 and a classifier 11. Ultrahigh-temperature vaporization treatment equipment (B) is composed of the second ash receiving hopper 13, an ultrahigh-temperature furnace 14, a powdered coal hopper 15 for improving combustion, a primary air fan 16 for conveying the powdered coal for improving combustion, an oxygen production apparatus 17 for oxygen-enriched combustion, a silica fume cooler 18, a collector 19 and a heat recovering device 20. In product preparation equipment (C), the feed rate of ultrafine particles in the ultrafine powder hoppers 12 and 22 is controlled with feeder 23 and 24 for optimum mixing and the particles are fed into a mixer 25. The ultrafine particles produced in the above-mentioned equipment for producing ultrafine powder are rich in silica. On the other hand, molten slag 21 is rich in alumina. Thereby, the aforementioned equipment for producing the ultrafine powder has also function to separate SiO2 and Al2O3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to equipment for producing ultrafine silica particles from coal combustion ash building materials, which are applied to concrete and construction material admixtures, and The present invention relates to ultrafine powder production equipment, such as equipment for producing ultrafine powder raw materials for paints, pigments, ceramics, etc., Bengara, Dichnia, etc. from coal combustion ash.

[Conventional technology]

FIG. 3 is a schematic side view showing an example of coal-fired boiler equipment.

Coal combustion ash includes tallinker ash 1 discharged from the bottom of a coal combustion furnace (furnace), and cinder ash 2 that settles and accumulates after being carried to the downstream of the furnace with exhaust gas.
There is fly ash 3 collected by electrostatic precipitators and hag filters. Generally speaking, the generation rate (collection rate) of coal ash is approximately 10% for Talinker Ash 1 and approximately 2% for Cinder Ash 2.
0%, fly ash 3 is said to be about 70%, and this ratio varies depending on the properties of the coal (ash's JI command, melting point of ash, particle size of coal, etc.), combustion conditions, combustion state, etc. ,
Fly ash 3 is the most common. Table 1 shows the properties (typical) of these coal ash.

Below is the margin Table 1 Properties of coal ash? Linker ash l is alumina with a high melting point (＾j!z
It is characterized by the fact that it does not contain 03) and has a large particle size, and when it is discharged from the furnace, it is in the form of a lump.

On the other hand, cinder ash 2 and fly ash 3 mainly contain silica (SiO■) and alumina (ANz(h)), and the particle size is relatively small, almost the same as the particle size of the pulverized coal to be burned. It is.

The above-mentioned coal combustion ash is a waste product discharged in large quantities from pulverized coal-fired power plants or coal-fired combustion furnaces, and various studies and studies have been conducted on how to use it effectively. has been put into practical use. Such effective usage methods can be broadly classified into two types. The first method is to mix and add coal combustion ash in its original form (properties) as part of the raw materials for cement, and the second method is to burn coal combustion ash and use it as an artificial aggregate for concrete. It is.

Conventionally, most of the coal combustion ash is used as a raw material for cement by the first method, and in this case, the amount of unburned content in the ash due to the properties (chemical fraction, particle size, specific surface area, shape, etc.) of coal combustion ash is Items that were unsuitable for use could not be used and were disposed of as waste.

Therefore, in order to expand the use of coal combustion ash, research has been carried out on techniques for processing coal combustion ash. Then, the second method was developed, in which coal combustion ash is incinerated to produce an artificial aggregate of several sizes, and this is used as aggregate for concrete.

On the other hand, the major general construction industry is asking the concrete industry to develop concrete with unprecedented ultra-high strength for the needs of high-rise buildings. Basic research to date has revealed that it is effective to mix ultrafine silica powder as a concrete admixture in order to obtain ultra-high strength concrete, and it is a well-known fact. According to this, the roles of the ultrafine particles as an admixture for ultra-high strength concrete are mainly the following three.

■ Significant improvement in concrete strength: conventional strength 150
~250kg/cm”300~1200kg/c
m2 is achieved.

? Concrete is a mixture of cement, aggregate (sand, jiyari, etc.) and water, and its handling and workability are also important.
Concrete containing ultra-fine particles has improved flow properties.

■ Alkaline aggregate reaction is a factor in the deterioration of concrete, but ultrafine silica (SiO■) has the effect of suppressing alkaline aggregate reaction, improving the durability of concrete.

[Problem to be solved by the invention]

As mentioned above, although coal combustion ash is effectively used as a raw material for cement or concrete aggregate, large amounts of coal combustion ash are emitted from coal-fired power plants or factories with coal-fired combustion furnaces. Coal ash cannot be completely disposed of, and securing an ash dump and countermeasures against environmental pollution are major issues.

On the other hand, the ultrafine concrete admixture for obtaining the ultra-high strength concrete is in short supply, and an admixture with better performance is being sought.

[Means to solve the problem]

In order to solve the above-mentioned conventional problems, the present invention provides ultrafine pulverization equipment equipped with a dry pulverizer for ultrafinely pulverizing coal combustion ash, and ultrafine pulverization equipment for pulverizing coal combustion ash by ultrahigh temperature vaporization. An ultrafine powder production facility comprising a high temperature vaporization facility and a product conditioning facility for mixing fine powders with different particle sizes produced by the ultrafine pulverization facility and the ultrahigh temperature vaporization facility, respectively, and In addition to this,
The present invention relates to an ultrafine powder production facility characterized by being equipped with a conduit for guiding the exhaust gas of the ultrahigh temperature vaporization treatment facility to a boiler furnace or a heat exchanger.

[Effect]

Coal combustion ash, for example coal ash produced from a furnace, is ultra-finely pulverized in a dry pulverizer of an ultra-fine pulverizer to become an ultra-fine powder. Further, coal combustion ash, such as cinder ash and fly ash, is subjected to ultra-high temperature vaporization treatment in an ultra-high temperature vaporization treatment facility to become ultra-fine powder. The two types of ultrafine powders with different particle sizes obtained through ultra-high temperature vaporization treatment and ultrafine pulverization treatment can be used individually, but it is best to use them after mixing them into the most suitable particle size distribution as an admixture for concrete. can. On the other hand, molten slag produced in ultra-high temperature vaporization processing equipment is used as concrete aggregate.

In addition, since the above-mentioned ultrafine pulverization processing equipment uses a dry pulverizer to perform ultrafine pulverization, it requires a drying device for fine powder slurry and a pulverizer to redisperse the aggregated fine powder, as in the case of wet pulverization. This simplifies the equipment and reduces energy requirements.

Furthermore, by guiding the exhaust gas from the ultra-high temperature vaporization treatment equipment to a boiler furnace or a heat exchanger, exhaust heat is recovered and energy is effectively utilized.

〔Example〕

FIG. 1 is a system diagram of an embodiment of the present invention. This embodiment is an example in which the apparatus is installed in a factory having a coal-fired boiler or coal-fired combustion furnace that discharges coal combustion ash by itself, such as a coal-fired power plant.

The equipment is roughly divided into three types: ultrafine pulverization equipment A, ultrahigh temperature vaporization equipment B, and product conditioning equipment C.

Among the coal combustion ashes, Talinker Ash 1 is in the form of lumps and is therefore suitable for use in ultrafine pulverization equipment A. On the other hand, cinder ash 2 and fly ash 3 are suitable for both ultrafine pulverization equipment A and ultrahigh temperature vaporization equipment B.

So, first of all, Talinkar Ash 1 is Belt Conhair 4
and transported to the first ash storage hopper 5. On the other hand, cinder ash 2 and fly ash 3 are conveyed to a second ash storage hopper 8 by belt conveyors 6 and 7.

The ultrafine pulverization processing equipment A is composed of a first ash receiving hopper 9, an ultrafine pulverization Ia 10, and a classifier 11.

Talinker ash 1 in the first ash storage hopper 5 and cinder ash 2 and fly ash 3 in the second ash storage hopper 8 are once received in the first ash receiving hopper 9, and then It is sent to the crusher 10 and is dry-pulverized into ultra-fine particles in which particles in the range of 0.1μ to 10μ account for 50% or more. . The dry powder discharged from the ultrafine pulverizer IO is sorted by a classifier, and particles of approximately 30 microns or more are returned to the inlet of the ultrafine pulverizer IALO to be re-pulverized. The ultrafine particles exiting the classifier 11 are temporarily stored in a first ultrafine particle hopper 12.

As described above, by using the dry ultrafine pulverizer 10, ultrafine particles are obtained without the need for a drying device and a pulverizer for redispersing aggregated ultrafine particles, compared to the case of wet pulverization. be able to.

The ultra-high temperature vaporization treatment equipment B includes a second ash receiving hopper 13,
Ultra-high temperature furnace 14, pulverized coal hopper 15 for auxiliary combustion, primary air fan (PAF) 16 for conveying pulverized coal for auxiliary combustion, oxygen production device (or oxygen cylinder) 17 for oxygen-enriched combustion, silica fume cooling device 18, Collection device 19, heat recovery device! 2
Constructed from 0.

Cinder ash 2 sent from second ash storage hopper 8
and fly ash 3 is transferred to the second ash receiving hopper 13
Once received at ) to burn.

? The temperature inside the ultra-high temperature furnace is between 2000℃ and 3000℃.
Alumina^2■03 (melting point 2015°C, which has a relatively high vaporization temperature)
The slag (with a vaporization temperature of 3500° C.) is discharged from the bottom of the furnace as molten slag 21, and is cooled to become a material such as aggregate for concrete. On the other hand, silica SiO■ (
The silica fume (melting point: 1730°C, vaporization temperature: 2230"C) is vaporized in the ultrahigh temperature furnace 14 and discharged from the ultrahigh temperature furnace 14 as gaseous silica fume. The silica fume cooling device 1
Cooled by 8, 50% in the range of 0.01μ to 1μ
The ultrafine particles that account for the above amount are collected and collected by the collection device 19 and temporarily stored in the second ultrafine powder hopper 22 .

Next, in the product adjustment equipment C, the ultrafine particles in the first and second ultrafine powder hoppers 12.22 are fed into the mixer 25 with the supply amount controlled by the feeder 23.24 for optimal blending. .

The ultrafine powder in the first ultrafine powder hopper 12 and the ultrafine powder in the second ultrafine powder hopper 22 generally differ in particle size by approximately one order of magnitude (ultra-high temperature treatment allows for the production of finer particles). Depending on the needs of ultra-high-strength concrete, for example, from the standpoint of close packing, the optimum blending of the two is carried out within a weight ratio of 5:95 to 95:5. In this way, the ultrafine powder is sufficiently dispersed and mixed in the mixer 25 and then sent to the product tank 26.

On the other hand, the combustion exhaust gas leaving the ultra-high temperature furnace 14 (2000°C~3
000"C (usually 2600°C) is cooled down to 1000°C or less (usually about 800°C) in a fume cooling device 18, and then sent to a heat recovery device 20 via a collection device 19 where it is used for oxygen production. After heating the oxygen-enriched combustion air from device 17, it is sent via exhaust gas line 30 to boiler furnace 27 for thermal energy recovery.

As mentioned above, ultra-high temperature vaporization treatment B requires auxiliary combustion by oxygen enrichment (using coal or heavy oil as the auxiliary fuel), but this exhaust gas is led to a coal-fired boiler or coal-fired combustion furnace for heat recovery. By doing so, you can make effective use of energy.

The ultrafine particles produced as described above are silica ridges (50% or more of SiO). On the other hand, 2L of molten slag is alumina rich (Ajz (h is 50% or more). Therefore, this ultrafine powder manufacturing equipment
! It can be said that it also has the function of separating it from 03.

Next, FIG. 2 is a system diagram of another embodiment of the present invention. This embodiment is an example in which coal combustion ash is transported from a remote coal-fired power plant or coal-fired combustion furnace to an ultrafine powder manufacturing facility.

Coal combustion ash from the truck 28 that transported the Talinker ash 1 and the truck 29 that transported the cinder ash 2 and fly ash 3 is transferred to the first ash storage hopper 5 and the second ash storage by a belt conveyor 30.31. It is stored in the hopper 8. After that, ultrafine powder is manufactured in the same process as in the first embodiment, and the product storage tank 26
stored in

In this embodiment, the exhaust gas leaving the ultra-high temperature furnace 14 is led to the heat exchanger 32 via the silica fume cooling device I8, the collection device I9 and the heat recovery device 20, and after the thermal energy is effectively utilized, It is released into the atmosphere from the chimney 33.

〔Effect of the invention〕

According to the present invention, coal combustion ash, which is discharged in large quantities from coal-fired boilers and coal-fired furnaces and which has traditionally been difficult to dispose of as industrial waste, is effectively utilized, and ultrafine powder and concrete aggregate useful as concrete admixtures are produced. It is possible to efficiently obtain molten slag.

In addition, since the ultrafine powder processing equipment of the present invention performs dry pulverization, it does not require a drying device for fine powder slurry and a crusher for redispersing aggregated fine powder, etc., as in the case of a wet type, and the equipment can be simplified. It is possible to reduce the amount of energy required.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of one embodiment of the present invention, and FIG. 2 is a system diagram of another embodiment of the invention. FIG. 3 is a schematic side view showing an example of coal-fired boiler equipment. A... Ultra-fine pulverization processing equipment, B... Ultra-high temperature vaporization processing equipment, C... Product conditioning equipment, 1... Talinker asche, 2... Cinder ash, 3... Fly ash, 4, 6.7... Belt conveyor, 5... First ash storage hopper, 8... Second ash storage hopper, 9... First ash receiving hopper, 10... Over Fine crusher, 11... Classifier, 12... First ultrafine hopper, l3... Second ash receiving hopper, 14.
... Ultra-high temperature furnace, l5... Pulverized coal hopper, 16... Primary air fan (PAF), 17... Oxygen production device, l8... Silica fume cooling device, 19... Collection device, 20... Heat recovery device, 2l... Molten slag, 22... Second ultrafine hopper, 23.24...
- Supply device, 25... Mixer, 26... Product storage tank, 27... Poiler, 28.
29...Truck, 30.31...Belt conveyor, 32...Heat exchanger, 33...Chimney.

Claims (2)

[Claims] (1) Ultrafine pulverization equipment equipped with a dry pulverizer for ultrafinely pulverizing coal combustion ash, ultrahigh temperature vaporization equipment for pulverizing coal combustion ash through ultrahigh temperature vaporization, and the above-mentioned ultrafine pulverization equipment and product conditioning equipment for mixing fine powders of different particle sizes produced by the ultra-high temperature vaporization equipment. The ultrafine powder manufacturing equipment according to claim (1), further comprising: (2) a pipe line for guiding exhaust gas from the ultra-high temperature vaporization treatment equipment to a boiler furnace or a heat exchanger.