METHOD FOR MANUFACTURING LIGHT-WEIGHT CONSTRUCTION MATERIAL USING WASTE PRODUCT AND LIGHT-WEIGHT CONSTRUCTION MATERIAL MANUFACTURED THEREBY 5 TECHNICAL FIELD The present invention relates to a method of manufacturing a lightweight construction material using wastes, and more particularly, to a method of a manufacturing lightweight construction material using wastes such as sewage 10 sludge, remicon sludge, spent foundry sand, power plant ash, incinerator residue, grinding stone residue, waste asbestos, and steel mill dust, and more particularly, to a lightweight construction material manufactured by the same. 15 BACKGROUND ART In general, sludge and all the residues as non-organic materials, which are generated in filtration plants or sewage treatment plants, factories or incinerating facilities and the like, are classified as wastes and are disposed of by a 20 specified method through a collection process. As a method of treating such wastes, attempts have been made to perform carbonization, solidification, composting, and incineration of wastes, and use the wastes as cement raw materials and thermal power plant fuels. -1- The carbonization is a process in which waste is put into a furnace combustion chamber and then the combustion chamber is heated to a temperature of 700-1200"C. However, such a carbonization process entails a problem in that since 5 offensive odor is not induced but carbonized solid waste is produced, the carbonized solid waste is required to be landfilled. The solidification is a process in which a solidifying agent is added to sludge having a water content of about 80 10 83% and then the solidified waste is landfilled or recycled for reuse. However, such a solidification process entails problems in that when the sludge treated with the solidifying agent is allowed to stand for more than about one year, organic materials of the sludge are decayed to cause gas to 15 be erupted or are leached into soil due to a problem associated with the solidifying agent or sludge particles, and in that when it rains, acidification of soil is induced due to acidic components contained in the rain. The composting is a process in which sludge is used as 20 compost. Such a composting process has a problem in that plants grow well at an earlier stage but soil is contaminated due to heavy metals over time so that the plants contain heavy metals or the growth of plants are inhibited. -2- The incineration is a process in which much installation and investment costs are required, but a failure frequently occurs due to rapid corrosion of an incineration machine to make it difficult to operate the machine continuously as well 5 as dioxin is generated during the incineration. In case of using sludge as the cement raw material, the construction material contains a large amount of heavy metal to cause harm to the human body and wastes such other inorganic materials are mass-produced in the production of 10 cement. Lastly, in case of using sludge as the thermal power plant fuel, when sludge is first dried, dioxin and offensive odor are induced, and electricity production efficiency is lower than that in case of using hard coal or soft coal as 15 the thermal power plant fuel. In order to solve or at least ameliorate these problems, a solution to recycle sludge has been proposed. Recycling of the sludge requires treatment of heavy metal contained in the 20 sludge and ensuring of economic efficiency, and recycled products should have functionality. For example, in Korean Patent Registration No. 10 0859002, there has been proposed a method of manufacturing artificial lightweight aggregate using sewage sludge, which -3comprises: grinding sewage sludge, coal fly ash, and clay into small particles having a size of less than 1mm; forming the mixture into a shaped body; calcining the shaped body at 1100 0 C-1200 0 C for 10-15 hours to obtain the artificial 5 lightweight aggregate. Further, in Korean Patent Registration No. 10-0450898, there has been proposed a method of manufacturing calcined construction materials using sewage sludge, which comprises: primarily drying and grinding sewage sludge in a dehydrated cake state for 24 hours; mixing the 10 ground sewage sludge with clay, silica sand, plaster, and blast furnace slag powder, forming the mixture into a shaped body, and secondarily drying the shaped body; and calcining the dried body at 900 C-1100 C for 13 hours to obtain the construction material. As such, many patents have proposed 15 various methods. The inventions of the above patents have an effect in that lightweight aggregate can be manufactured without any leaching of heavy metals, but still entails a problem in that much energy is consumed in the course of manufacturing the construction material, diversification of 20 products is difficult, and the strength is weak in case of a product manufactured using the residues generated after incineration. Thus, in order to solve or at least ameliorate the problems, the present inventor has filed a patent (filing -4number: 10-2009-0123481) that discloses a method of manufacturing a lightweight construction material using sludge waste, in which feldspar, bentonite, zeolite, less, mica, and agalmatolite are added to sewage sludge waste, the 5 mixture is formed into a shaped body, and the shaped body is calcined. In addition, the present inventor has found that wastes such as remicon sludge, spent foundry sand, power plant ash, and waste asbestos are added to sewage sludge or wastes such 10 as incinerator residue, grinding stone residue, spent foundry sand, power plant ash, and steel mill dust are added to remicon sludge, an additive is added to the waste mixture, the resultant mixture is formed into a shaped body, and the shaped body is calcined, so that strength, water permeability, 15 and nonflammability of an obtained lightweight construction material can be increased as well as a lightweight construction material having a proper color can be manufactured despite non-use of a separate pigment. 20 DISCLOSURE OF INVENTION TECHNICAL PROBLEM Desirablythe present invention provides a method of recycling wastes such as sewage sludge, remicon sludge, spent -5foundry sand, power plant ash, incinerator residue, grinding stone residue, and waste asbestos. Desirably the present invention provides a lightweight construction material that is excellent in strength and water 5 permeability through the recycling of wastes. And desirably provides a lightweight construction material manufactured by the same. TECHNICAL SOLUTION 10 According to a first aspect of the present invention, there is provided a method of a manufacturing a water permeable and lightweight construction material using wastes, the method comprising: (a) preparing a waste mixture by adding at least one 15 waste selected from the group consisting of remicon sludge, spent foundry sand and waste asbestos to sewage sludge; (b) forming a resultant mixture comprising an additive by adding the additive selected from the group consisting of feldspar, bentonite, zeolite, less, mica and agalmatolite to 20 the waste mixture; (c) preparing a shaped body by forming the resultant mixture comprising the additive; and (d) obtaining the lightweight construction material by calcining the shaped body in a calcining furnace at a 25 temperature of 1100-1145C for 3-5 hours, wherein the sewage sludge has a water content of 70-80%; -6the waste mixture comprises 10-100 parts by weight of the at least one waste selected the group consisting of remicon sludge, spent foundry sand, waste asbestos and power plant ash, based on 100 parts by weight of the sewage sludge; 5 and the additive comprises 10-35 parts by weight of the feldspar, 10-30 parts by weight of the bentonite, 10-60 parts by weight of the zeolite, 15-60 parts by weight of the less, 15-60 parts by weight of the mica, and 5-25 parts by weight 10 of the agalmatolite, based on 100 parts by weight of the waste mixture. According to a second aspect of the present invention, there is provided a method of manufacturing a fireproof and sound-absorbing and lightweight construction material using 15 wastes, the method comprising: (a) preparing a waste mixture by adding at least one waste selected from the group consisting of remicon sludge, spent foundry sand, and waste asbestos to sewage sludge; (b) forming a resultant mixture comprising an additive 20 by adding the additive selected from the group consisting of feldspar, bentonite, zeolite, less, mica and agalmatolite to the waste mixture; (c) preparing a shaped body by forming the resultant mixture comprising the additive; and 25 (d) obtaining the lightweight construction material by calcining the shaped body in a calcining furnace at a -7temperature of 1150-1200 C for 3-5 hours, wherein the sewage sludge has a water content of 70-80%; the waste mixture comprises 10-100 parts by weight of the at least one waste selected the group consisting of 5 remicon sludge, spent foundry sand, waste asbestos and power plant ash, based on 100 parts by weight of the sewage sludge; and the additive comprises 10-35 parts by weight of the feldspar, 10-30 parts by weight of the bentonite, 10-60 parts 10 by weight of the zeolite, 15-60 parts by weight of the less, 15-60 parts by weight of the mica, and 5-25 parts by weight of the agalmatolite, based on 100 parts by weight of the waste mixture. According to a third aspect of the present invention, 15 there is provided a method of manufacturing a water permeable and lightweight construction material using wastes, the method comprising: (a) preparing a waste mixture by adding at least one waste selected from the group consisting of incinerator 20 residue, grinding stone residue, spent foundry sand, waste asbestos and steel mill dust to remicon sludge; (b) forming a resultant mixture comprising an additive by adding the additive selected from the group consisting of feldspar, bentonite, zeolite, less, mica and agalmatolite to 25 the waste mixture; -8- (c) preparing a shaped body by forming the resultant mixture; and (d) obtaining the lightweight construction material by 5 calcining the shaped body in a calcining furnace at a temperature of 1100-1145C for 3-5 hours, wherein the waste mixture comprises 10-65 parts by weight of the at least one waste selected the group consisting of incinerator residue, grinding stone residue, 10 spent foundry sand, waste asbestos, and steel mill dust, based on 100 parts by weight of the remicon sludge; and the additive comprises 10-35 parts by weight of the feldspar, 10-30 parts by weight of the bentonite, 10-60 parts by weight of the zeolite, 15-60 parts by weight of the less, 15 15-60 parts by weight of the mica, and 5-25 parts by weight of the agalmatolite, based on 100 parts by weight of the waste mixture. According to a fourth aspect of the present invention, there is provided a method of manufacturing a fireproof and 20 sound-absorbing and lightweight construction material using wastes, the method comprising: (a) preparing a waste mixture by adding at least one waste selected from the group consisting of incinerator residue, grinding stone residue, spent foundry sand, waste 25 asbestos and steel mill dust to remicon sludge; (b) forming a resultant mixture comprising an additive by adding the additive selected from the group consisting of -8afeldspar, bentonite, zeolite, less, mica and agalmatolite to the waste mixture; (c) preparing a shaped body by forming the resultant mixture; and 5 (d) obtaining the lightweight construction material by calcining the shaped body in a calcining furnace at a temperature of 1150-1200'C for 3-5 hours, wherein the waste mixture comprises 10-65 parts by weight of the at least one waste selected the group 10 consisting of incinerator residue, grinding stone residue, spent foundry sand, waste asbestos, and steel mill dust, based on 100 parts by weight of the remicon sludge; and the additive comprises 10-35 parts by weight of the feldspar, 10-30 parts by weight of the bentonite, 10-60 parts 15 by weight of the zeolite, 15-60 parts by weight of the less, 15-60 parts by weight of the mica, and 5-25 parts by weight of the agalmatolite, based on 100 parts by weight of the waste mixture. -8b - BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a process flowchart illustrating the manufacture of a lightweight construction material using wastes according to an embodiment of the present invention. 5 BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, it has been found that in the case where a method is performed which comprises the steps of: adding to sewage sludge at least one waste selected from 10 the group consisting of remicon sludge, spent foundry sand, waste asbestos, and power plant ash to prepare a waste mixture; adding an additive to the waste mixture; forming the resultant mixture into a shaped body; and calcining the shaped body, the waste can be recycled and simultaneously a 15 lightweight construction material excellent in strength, water permeability, and nonflammability can be manufactured. In the present invention, a water-permeable sidewalk block and a lightweight panel as lightweight construction materials were manufactured by adding remicon sludge, spent 20 foundry sand, and power plant ash to sewage sludge to prepare a waste mixture, adding an additive comprising feldspar, bentonite, zeolite, less, mica, and agalmatolite to the waste mixture to form a resultant mixture, forming the resultant mixture into a shaped body using a press, and 25 calcining the shaped body at 1100-1200 C. As a result of -9evaluation of the physical properties of the manufactured water-permeable sidewalk block and lightweight panel, it could be confirmed that the sidewalk block has excellent water permeability and strength, and the lightweight panel 5 has excellent strength and nonflammability. Thus, in one aspect, the present invention is directed to a method of a manufacturing a lightweight construction material using wastes, the method comprising the steps of: (a) preparing a waste mixture by adding at least one waste 10 selected from the group consisting of remicon sludge, spent foundry sand, waste asbestos and power plant ash to sewage sludge; (b) forming a resultant mixture comprising the additive by adding an additive selected from the group consisting of feldspar, bentonite, zeolite, less, mica and 15 agalmatolite to the waste mixture; (c) preparing a shaped body by forming the resultant mixture comprising the additive; and (d) obtaining the lightweight construction material by calcining the shaped body in a calcining furnace, and a lightweight construction material manufactured by said 20 method. FIG. 1 shows a process flowchart illustrating the manufacture of a lightweight construction material using wastes according to an embodiment of the present invention. The sewage sludge used in the present invention in 25 several steps of a sewage treatment process -10- Sewage sludge used in the present invention refers to a material that is obtained in various steps of a sewage treatment process, and sludge that leaches from the filtration and precipitation of raw water introduced from a 5 water pipe or a water intake well in a water purification process. Because sewage sludge contains organic materials and is high in water content, it is disposed of by a method in which sewage sludge is buried after being stabilized and dehydrated by an anaerobic treatment, or it is dumped to the 10 sea after being treated by hauling of sewage sludge into river or sea, or water lifting. However, the sludge reclamation method has a drawback in that it is difficult to secure a landfill site due to an increase in the amount of sludge buried, and the sludge dumping method has a 15 shortcoming in that a sludge treatment process is complicated and a risk of environmental pollution cannot be excluded completely. The sewage sludge is collected in the form of a cake, which has a water content of about 70-80% and is stored in a 20 sludge storage tank. Thereafter, the sewage sludge stored in the sludge storage tank is mixed with another waste via a supply unit to prepare a waste mixture. The waste may be selected from the group consisting of remicon sludge, spent foundry sand, waste asbestos, and power plant ash. -11- In the present invention, the remicon sludge is waste generated in the manufacture of concrete as a resultant mixture obtained by properly mixing cement with sand, gravel, and aggregate and kneading the mixture with water. The 5 remicon sludge is a complex inorganic material exhibiting alkalinity. The remicon sludge has an excellent strength and a low calcination temperature so that the amount of fuel used can be reduced. In addition, the remicon sludge has a dark color, and thus a construction material can be manufactured 10 without using a separate dark pigment. The spent foundry sand is sand that is remained after casting and contains quartz particles (i.e., silica sand: quartz grain sand containing SiO 2 component) in a large amount and feldspar and clay in a small amount. When the spent 15 foundry sand is used to manufacture the construction materials, the strength can be improved. The waste asbestos is a material that is generated from construction materials, fireproofing materials, and electrical insulating materials. Asbestos as a hydrous 20 silicate mineral, which has a fibrous structure and is abundant of magnesium, has been widely used as a construction material. However, asbestos was identified as a material that can induce lung cancer or asbestosis or cause malignant tumor to pleura when a person takes asbestos powder through 25 respiration, and thus special attention is paid to treatment -12of wastes generated in a building dismantling process. The asbestos has a specific gravity of 2.5-2 and a tensile strength of about 13g/d, is formed by the breakdown of serpentinite, amphibole and the like, and comprises magnesium 5 silicate and calcium as main components. The asbestos is divided into chrysotile, amosite, crocidolite, tremolite, actinolite, and anthophyllite. The use of the waste asbestos in the manufacture of the construction materials can make products lightweight and improve nonflammability, water 10 permeability and strength. The power plant ash is an iron-containing waste that is generated when soft coal, hard coal, and a mixture thereof are used as fuels in a power plant. The use of the power plant ash in the manufacture of the construction materials 15 can make products lightweight and improve strength. The amount of the waste added to the sewage sludge may be properly adjusted depending on the kind and the number of wastes, but the waste is preferably used in an amount of 10 100 parts by weight based on 100 parts by weight of the 20 sewage sludge. If the content of the waste is less than 10 parts by weight based on 100 parts by weight of the sewage sludge, the products cannot be made lightweight. On the contrary, if the content of the waste exceeds 100 parts by weight based on 100 parts by weight of the sewage sludge, the 25 strength of the products will be deteriorated and organic -13components will be combusted, which makes it impossible to manufacture products conforming to the standard. When the waste mixture is prepared, an additive selected from the group consisting of feldspar, bentonite, zeolite, 5 less, mica, agalmatolite is added to the waste mixture to form a resultant mixture containing the additive. The additive can be selectively used depending on the characteristics of a construction material which it is desired to produce. 10 It is known that feldspar is an aluminum silicate mineral having a Mohs hardness of 6 and a specific gravity of 2-2.7. Also, feldspar cleaves in two directions at 90 degrees, and takes a white, grayish, or dark brownish color, etc. In the present invention, when feldspar is added to the 15 waste mixture, the adhesive force and the strength of construction materials can be improved and the calcination temperature can be lowered to save energy. In the present invention, bentonite is a natural clay mineral formed by transformation of fine glassy particles 20 derived from volcanic ash. Bentonite refers to a clay that mainly contains montmorillonite as a mineral belonging to a monoclinic system, which has the same crystal structure as that of mica. When bentonite is added to the waste mixture in the manufacture of construction materials, an adhesive 25 force of the construction materials can be improved. -14- In the present invention, zeolite is a generic term for minerals as aluminosilicate hydrates of alkaline and alkaline earth metal. Zeolite may be used irrespective of the kind thereof as long as it has a structure in which (Si, Al) 04 5 tetrahedrons are linked together to form a three-dimensional mesh. When zeolite as a porous material is added to the waste mixture, the construction materials can be made lightweight, water permeability can be improved, and the waste can be deodorized. 10 In the present invention, less refers to a sediment consisting of particles having a diameter of from 0.002 to 0.005mm, which is equal to the size of a silt. Loess takes a yellow-brownish color and is not easily subjected to weathering. In addition, it is known that less mainly 15 contains quartz. Besides, less is known as being calcareous as containing pyroxene, amphibole, and the like. When less is added to the waste mixture in the manufacture of the construction materials, their strength can be increased due to excellent sintering properties, far-infrared ray radiating 20 and deodorizing effects can be obtained, the calcination temperature can be lowered to save energy. In the present invention, mica is an important rock forming mineral among granites, i.e., a layered silicate mineral. Mica has a Mohs hardness of 2.5-4 and a specific 25 gravity of from 2.75-3.2. Also, mica takes a yellowish, -15brownish, and greenish color. It is known that germanium is contained in mica at a concentration of about 2.82 ppm so that the spectral distribution of far-infrared rays beneficial to the human body is high and thus a degree of 5 radiation of far-infrared rays is high. When mica is added to the waste mixture, the deodorizing and antibacterial effects can be exhibited, an adhesive force can be increased when the resultant mixture are formed into a shaped body, mechanical abrasion can be reduced as mica does not contain 10 an arenaceous component. In the present invention, mica includes lepidolite and the like. In the present invention, agalmatolite has the following general chemical formula: A1 2
O
3 4SiO 2
H
2 0. The theoretical content ratio of the components of agalmatolite is as 15 follows: A1 2 0 3 : 28.3%, SiO 2 : 66.7%, H 2 0: 5%. Agalmatolite has various colors ranging from a white base color to a greenish base color. In addition, agalmatolite has a specific gravity of 2.7-2.9 and a Mohs hardness of 1-2. When agalmatolite is added to the waste mixture in the manufacture of construction 20 materials, a Pozzolanic reaction can be induced with water to impart the strength to the construction materials, and resistance to water and corrosion and sound absorbing property or water permeability can be improved. The additive may comprise 10-35 parts by weight of 25 feldspar, 10-30 parts by weight of bentonite, 10-60 parts by -16weight of zeolite, 15-60 parts by weight less, 15-60 parts by weight of mica, and 5-25 parts by weight of agalmatolite based on 100 parts by weight of the waste mixture. If the content of the additive used is less than the lower limit of 5 each range mentioned above, a desired effect cannot be obtained. On the other hand, if the content of the additive used exceeds the upper limit of each range mentioned above, it is disadvantageous in terms of economic efficiency. A resultant mixture containing the additive is formed 10 into a shaped body in a press forming machine through a bucket elevator, a distribution conveyor with large silo, and a small distribution silo. In the present invention, the forming step can be performed in a general method, but is preferably performed by 15 pressing the resultant mixture using a dry-type press under the pressure of 500 to 1500 tons. The shaped body is transferred to a calcining furnace through a fireproof paneled bogie system, and then is calcined in the calcining furnace to obtain the lightweight 20 construction material. In the present invention, the calcination step can be performed at a temperature of from 1100 to 1200 C for 3-5 hours using a general calcination method such as using a tunnel kiln, etc. If the calcination temperature is less -17 than 1100 C, there is a risk that the strength of the lightweight construction material will be deteriorated. Contrarily, if the calcination temperature exceeds 1200 C, there is a risk that water permeability of the lightweight 5 construction material will be decreased. Particularly, if the calcination temperature is in a range of 1100-1145C, a water permeable construction material can be obtained, and if the calcination temperature is in a range of 1150-1200 C, a fireproof and sound-absorbing 10 construction material can be obtained. The water permeable construction material can be exemplified by a water-permeable sidewalk block, and the fireproof and sound-absorbing construction material can be exemplified by a lightweight panel, a lightweight brick, or a lightweight aggregate. 15 Generally, the reason for this is that if the calcination temperature is less than the lower limit of the range of 1145-1150 C, pores are formed in the product, and if the calcination temperature exceeds the upper limit of the range mentioned above, the pores are melted, leading to an 20 increase in volume. In the calcination step, organic hazardous components are oxidized and inorganic hazardous components are mixed with the additive so that the physical properties of the hazardous components are transformed into those of non-toxic components in a magnetization process. -18 - The obtained lightweight construction material is cut off by a cutter, and then is packaged by an automatic packager via a conveyor. Thereafter, the packaged lightweight construction material is transported using a 5 pallet and is stored in a product repository. In the meantime, in the present invention, it has been found that in the case where a method is performed which comprises the steps of: adding to remicon sludge at least one waste selected from the group consisting of incinerator 10 residue, grinding stone residue, spent foundry sand, waste asbestos, steel mill dust, and power plant ash to prepare a waste mixture; adding an additive to the waste mixture; forming the resultant mixture into a shaped body; and calcining the shaped body, the waste can be recycled and 15 simultaneously a lightweight construction material excellent in strength, water permeability, and nonflammability can be manufactured. When the remicon sludge is used instead of the sewage sludge, it is advantageous that the strength of the product can be further improved and a separate dark pigment 20 needs not to be used due to its dark color. In the present invention, a water-permeable sidewalk block and a lightweight panel as lightweight construction materials were manufactured by adding incinerator residue, grinding stone residue, spent foundry sand, waste asbestos, 25 steel mill dust, and power plant ash to remicon sludge to -19prepare a waste mixture, adding to the waste mixture an additive comprising feldspar, bentonite, zeolite, less, mica, and agalmatolite to form a resultant mixture, forming the resultant mixture into a shaped body using a press, and 5 calcining the shaped body at 1100-1200 C. As a result of evaluation of the physical properties of the manufactured water-permeable sidewalk block and lightweight panel, it could be confirmed that the sidewalk block has excellent water permeability and strength, and the lightweight panel 10 has excellent strength and nonflammability. Thus, in one aspect, the present invention is directed to a method of manufacturing a lightweight construction material using wastes, the method comprising the steps of: (a) preparing a waste mixture by adding at least one waste 15 selected from the group consisting of incinerator residue, grinding stone residue, spent foundry sand, waste asbestos, steel mill dust and power plant ash to remicon sludge; (b) forming a resultant mixture containing the additive by adding an additive selected from the group consisting of feldspar, 20 bentonite, zeolite, less, mica, agalmatolite to the waste mixture; (c) preparing a shaped body by forming the resultant mixture; and (d) obtaining the lightweight construction material by calcining the shaped body in a calcining furnace, and a lightweight construction material manufactured by said 25 method. -20- The remicon sludge is waste generated in the manufacture of concrete as a resultant mixture obtained by properly mixing cement with sand, gravel, and aggregate and kneading the mixture with water. The remicon sludge is a complex 5 inorganic material exhibiting alkalinity. If the remicon sludge is used in the manufacture of the construction material, the amount of fuel used can be reduced due to a low calcination temperature and the strength of the product can be improved. In addition, the remicon sludge has a dark 10 color, and thus the construction material can be manufactured without using a separate dark pigment. The incinerator residue is a residue generated during incineration in daily waste incinerating facilities. When the daily waste is incinerated, about 20-30% thereof is 15 remained as a residue. Except large-sized wastes such as re used and recycled products, and waste furniture and home appliance, and food wastes for raw materials for feed production and composting among daily wastes, inflammable wastes are mainly incinerated in the daily waste incinerating 20 facilities. When organic materials are incinerated during the incineration, the inflammable wastes consist of inorganic materials. When the incinerator residue is used in the manufacture of the construction material, it is advantageous that the product can be made lightweight along with recycling 25 of the wastes. -21- The grinding stone residue is powder generated from grinding stone when the surface of a material such as metal is grinded smoothly, or grinding stone waste remained after using the grinding stone. The grinding stone residue 5 contains silicon dioxide (SiO 2 ) as a main component. When the grinding stone residue is used in the manufacture of the construction material, it is advantageous that the product has an excellent strength and can be made lightweight. The steel mill dust is a solid particulate that is 10 generated in an ironworks producing iron materials such as steel plate, steel pipe and the like. The steel mill dust to be used may be collected in a dust collector of the ironworks. Any steel mill dust may be used as long as it is generated in the ironworks, and contains iron, sulfur and the like as main 15 components. When the steel mill dust is used in the manufacture of the construction material, it is advantageous that the strength of the product can be improved as having iron components and the sintering process can be performed smoothly even at low temperature to reduce the amount of fuel 20 used during the calcination of the shaped body. The spent foundry sand and the waste asbestos are the same as mentioned above. The amount of the waste added to the remicon sludge may be properly adjusted depending on the kind and the number of 25 wastes, but the waste is preferably used in an amount of 10 -22- 65 parts by weight based on 100 parts by weight of the remicon sludge. If the content of the waste is less than 10 parts by weight or exceeds 65 parts by weight based on 100 parts by weight of the sewage sludge, a crack may occur in 5 the products. When the waste mixture is prepared, an additive selected from the group consisting of feldspar, bentonite, zeolite, less, mica, agalmatolite is added to the waste mixture to form a resultant mixture containing the additive. The 10 additive can be selectively used depending on the characteristics of a construction material which it is desired to produce. The additive may comprise 10-35 parts by weight of feldspar, 10-30 parts by weight of bentonite, 10-60 parts by 15 weight of zeolite, 15-60 parts by weight less, 15-60 parts by weight of mica, and 5-25 parts by weight of agalmatolite based on 100 parts by weight of the waste mixture. If the content of the additive used is less than the lower limit of each range mentioned above, a desired effect 20 cannot be obtained. On the other hand, if the content of the additive used exceeds the upper limit of each range mentioned above, it is disadvantageous in terms of economic efficiency. A resultant mixture containing the additive is formed into a shaped body in a press forming machine through a -23 bucket elevator, a distribution conveyor with large silo, and a small distribution silo. In the present invention, the forming step can be performed in a general method, but is preferably performed by pressing the resultant mixture using 5 a dry-type press under the pressure of 500 to 1500 tons. The shaped body is transferred to a calcining furnace through a fireproof paneled bogie system, and then is calcined in the calcining furnace to obtain the lightweight construction material. 10 In the present invention, the calcination step can be performed at a temperature of from 1100 to 1200 C for 3-5 hours using a general calcination method such as using a tunnel kiln, etc. If the calcination temperature is less than 1100 C, there is a risk that the strength of the 15 lightweight construction material will be deteriorated. Contrarily, if the calcination temperature exceeds 1200 C, there is a risk that water permeability of the lightweight construction material will be decreased. Particularly, if the calcination temperature is in a 20 range of 1100-1145C, a water permeable construction material can be obtained, and if the calcination temperature is in a range of 1150-1200 C, a fireproof and sound-absorbing construction material can be obtained. The water permeable construction material can be exemplified by a water-permeable -24sidewalk block, and the fireproof and sound-absorbing construction material can be exemplified by a lightweight panel, a lightweight brick, or a lightweight aggregate. Generally, the reason for this is that if the 5 calcination temperature is less than the lower limit of the range of 1145-1150 C, pores are formed in the product, and if the calcination temperature exceeds the upper limit of the range mentioned above, the pores are melted, leading to an increase in volume. 10 The obtained lightweight construction material is cut off by a cutter, and then is packaged by an automatic packager via a conveyor. Thereafter, the packaged lightweight construction material is transported using a pallet and is stored in a product repository. 15 The present invention is characterized in that it uses sewage sludge or remicon sludge which has a water content of 70-80% so that when the sludge is mixed with other waste and additive, separate water needs not to be used. Thus, waste water is not generated and the shaped body is subjected to 20 the calcinations process, but not subjected to a dry process after the mixing and forming process. A general forming process of a general construction material requires water. If the calcination process is performed without performing the dry process, water remained 25 in the shaped body is erupted, causing a problem in that a -25crack occurs in the product. In general, if the shaped body is cooled immediately after completing the calcination process, there is a risk that a crack may occur in the product. Thus, the shaped body is required to be slowly 5 cooled for about 10-234 hours, making it difficult to mass produce the product. However, the construction material of the present invention has pores formed through eruption of organic gas and water. Thus, it is advantageous that the calcinations 10 process can be performed without any dry process, or no crack occur in the product although the cooling process is performed immediately after completing the calcination process, 15 EXAMPLES Hereinafter, the present invention will be described in further detail with reference to examples. It will be obvious to those skilled in the art that these examples are illustrative purposes only and are not to be construed to 20 limit the scope of the present invention. Example 1 : Manufacture of Lightweight Construction Material Using Sewage Sludge As shown in Table 1 below, a waste mixture was prepared 25 using a mixer, and an additive was added to the prepared -26waste mixture to form a resultant mixture containing the additive. Then, the resultant mixture containing the additive was formed into a shaped body under the pressure of 1,000 tons using dry press forming machine (INOCATOR). 5 Thereafter, the shaped body was calcined using a tunnel kiln (available from GUN WOO Carbide Co., Ltd.) to obtain a lightweight construction material. The present invention used a sewage sludge having a water content of 75-80%, which was produced in the form of a 10 cake in a sewage treatment plant situated in Gwangju-si, Gyeonggi-do, South Korea, and then was immediately transported without any other treatment processes. The present invention also used a remicon sludge that was generated in the manufacture of concrete by SANHA Co., 15 Ltd. situated in Namyangju-si, Gyeonggi-do, South Korea. The remicon sludge has a water content of 80% and contains alkaline chemical and limestone. The present invention also used a spent foundry sand containing silicon dioxide and dust, which was generated 20 after being used at high temperature for casting at a foundry situated in Incheon Namdong Induspark. The present invention also used a waste asbestos which was supplied from a construction waste site situated in Hapjeong-dong, Pyeongtaek-si, Gyeonggi-do, South Korea. The 25 waste asbestos used crocidolite, chrysotile, or amosite. -27- The present invention also used a power plant ash as a soft coal-containing residue, which was supplied from a thermal power plant situated in Dangjin-gun, Chungnam, South Korea. The power plant ash contains silicon dioxide(SiO 2 ), 5 iron, chrome, and sulfur. The present invention also used an incinerator residue that was supplied from a landfill site of a metropolitan area situated in Backsuk-myeon, Seo-gu, Incheon-si, South Korea. The incinerator residue contains phosphorus, alkaline residue, 10 silicate, dust, and iron. The present invention also used a grinding stone residue that was supplied from Ihhwa Industrial Co., Ltd. situated in Pocheon-si, Gyeonggi-do, South Korea. The grinding stone residue has a particle size of more than 325 mesh of a 15 mineral grinding stone. The present invention also used a steel mill dust containing iron (Fe) and silicon dioxide (SiO 2 ), which was supplied from Hyundai Steel situated in Dangjin-gun, Chungnam, South Korea. 20 In addition, feldspar has the chemical formula of K 2 0 9 Na 2 0 3 Si0 2 ., which consists of three chemical compounds. In case of feldspar, a product having a particle size of less than 2 mm was purchased from the Imgae mine located in Jeongseon-gun, Kangwondo, Korea, and in case of bentonite, a 25 product having a particle size of less than 3 mm was -28purchased from SR GREEN TEC Co., Ltd. zeolite was purchased from SR GREEN TEC Co., Ltd. In addition, in case of less, a product having a particle size of less than 2 mm was purchased from Poonghyang Loess Co., Ltd. In addition, in 5 case of mica, a product having a particle size of less than 2 mm was purchased in Bonghwa-gun, Gyeongsangbuk-do, South Korea. Agalmatolite was purchased in an agalmatolite mine. [Table 1] Classification Components CalcinationCalcination Products (wt%) time temperature sewage sludge water Example 1 40, remicon 3 00 1140'C permeable sludge 40, sidewalk zeolite 20 blocks sewage sludge Example 2 40, remicon 3 0l0 1155C lightweight sludge 40, bricks zeolite 20 sewage sludge 45, wastelihwgt Example 3 asbest 3: 50 1150C lightweight asbestos 40, panels mica 15 sewage sludge 50, spent lightweight Example 4 foundry sand 3: 50 1150 C bricks 30, bentonite 20 sewage sludge water Example 5 50, power 3: 40 1140'C permeable plant ash 35, sidewalk mica 15 blocks remicon sludge 50, lightweight Example 6 incinerator 4: 00 1165 0 C bricks residue 40, zeolite 10 Example 7 remicon sludge 4 00 1145C water 50, permeable 29 incinerator sidewalk residue 40, blocks zeolite 10 remicon sludge water 50, grinding Example 8 stone residue 3: 40 1120'C sidewalk 30, feldspar blocks 20 blocks remicon sludge 50, spent lightweight Example 9 foundry sand 4: 10 1160C bricks 35, bentonite 15 remicon sludge Example 10 45, power 4: 10 1155 C lightweight plant ash 25, bricks mica 30 remicon sludge water 40, steel mill permeable Example 11 dust40, 3: 30 1140C sidewalk agalmatolite blocks 20blocks remicon sludge Example 12 50, wast 3: 50 1170'C lightweight asbestos 35, panels zeolite 15 sewage sludge 40, remicon Example 13 sludge 20, 3 20 1165 0 C lightweight power plant bricks ash 20,zeolite 20 sewage sludge 45, remicon Example 14 sludge 20, 3 30 1165 0 C lightweight waste asbestos bricks 20, bentonite 15 remicon sludge 50, grinding Example 15 stone residue 3 50 1155C lightweight 20, steel mill bricks dust15, feldspar 15 remicon sludge 3 5l0 1155C lightweight Example 16 3:, pent1155___C ._____ 50, spent bricks 30 foundry sand 20, waste asbestos 15, bentonite 15 As shown in the results of Examples 1 and 2 and Examples 6 and 7, it was confirmed that the kind of the finally produced products vary depending on the calcination 5 temperature although the finally produced products have the same components. The reason for this is that pores may be formed or not formed in the products depending on the calcination temperature. That is, if the calcination temperature is less than 1145C, the pores are maintained in 10 the products. On the contrary, if calcination temperature is less than 1150 C, the pores formed in the products are melted to vanish. Comparative Example 1-4: Manufacture of Lightweight 15 Construction Material Using Sewage Sludge In comparative examples 1-4, the lightweight construction materials were manufactured in the same manner as that in the above Examples 1-16 except that sewage sludge was used instead of the waste mixture. 20 [Table 2] Components (wt%) Calcination SFeldsparLoessBentoniteZeolitetemperature Products sludge time (C) -31 water Comparative 40 20 40 1140 3:30 permeable Example 1 sidewalk blocks water Comparative 50 20 30 - 1140 3:30 permeable Example 2 sidewalk blocks Comparative 50 - - - 50 1170 4:10 lightweight Example 3 panels Comparative 50 - 50 - 1190 4:20 lightweight Example 4 bricks Test Example 1: Physical Properties Test on Construction Materials manufactured in Examples and Comparative Examples Specific gravity, water permeability, compressive 5 strength, nonflammability, and color were measured on the lightweight construction materials manufactured in Examples and Comparative Examples. Specific gravity, water permeability, and compressive strength of the lightweight construction materials were respectively measured by KSF2353, 10 KSF 2322 (2000), and KSF4004 (2008), which are the Korean Standard Test Methods. Nonflammability of the construction materials was measured in such a manner that they were maintained at 1000 C for one hour and then their appearances were observed. 15 [Table 3] Specific Water Compressive Nonflamm gravity permeability strength Color (g/cm 3 ) (cm/s) (N/m 2 ) Example 68/100 3.9x1O 2 24 good charcoal 1 gray Example 68/100 1.5x10-2 24 good charcoal - 32 - 2 gray Example 62/100 1. 9x10-2 26 good light gray 3 6 / 0 . x 0 23g oli h gr Example 68/100 3.2x10-2 23 good light gray 4 Example 58/100 3.7x10-2 23 good light gray Example 62/100 1.5x10-2 21 good charcoal 6 gray Example 62/100 3.8x10-2 21 good charcoal 7 gray Example 64/100 1.2x10 2 24 good charcoal 8 gray Example 72/100 3.2x10 2 26 good charcoal 9 gray Example 64/100 1.2x10-2 27 good charcoal 10 gray Example 68/100 3.8x10-2 28 good charcoal 11 gray Example 62/100 1.7x10-2 24 good charcoal 12 gray Example 66/100 1.4x1O 2 25 good charcoal 13 gray Example 66/100 1. 5x10-2 26 good charcoal 14 ______ gray Example 66/100 1.6x 10- 24 good caca 15 gray Example 68/100 1.7x1O 2 23 good charcoal 16 gray Compara tive 58/100 2.2x10-2 17 good light gray Example 1 Compara tive 61/100 2.4x10 2 16 good light gray Example 2 Compara tive 66/100 0.7x10-2 16 good light gray Example 3 Compara tive 77/100 0.6x10-2 17 good light gray Example 4 -33- It could be seen from Table 3 that when the manufactured lightweight construction materials contain waste asbestos, power plant ash, incinerator residue, or grinding stone, they 5 can be made lightweight and are relatively excellent in compressive strength as compared to containing grinding stone, steel mill dust, spent foundry sand, power plant ash, or waste asbestos In addition, it was confirmed that in Example 1, Example 10 5, Example 7, and Example 11, in which the lightweight construction materials were manufactured as water-permeable sidewalk blocks, water permeability of the products were excellent, and in Example 1-16 and Comparative Example 1-4, no combustion occurred in all the construction materials and 15 no change was observed on the outer surface of the construction materials. Besides, no hazardous gas was generated in the process of maintaining the construction materials at 1000 0 C for one hour. 20 In the end, it was confirmed that when the construction materials contain remicon sludge (Examplel-2, 6-16), they shows charcoal gray color. 25 -34- INDUSTRIAL APPLICABILITY As described above, according to the present invention, the wastes such as sewage sludge, remicon sludge, spent foundry sand, power plant ash, incinerator residue, grinding 5 stone residue, waste asbestos, and steel mill dust can be recycled as lightweight construction materials which are excellent in strength, water permeability, and nonflammability. Although the present invention has been described in 10 detail with reference to the specific features, it will be apparent to those skilled in the art that this description is only for a preferred embodiment and does not limit the scope of the present invention. Thus, the substantial scope of the present invention will be defined by the appended claims and 15 equivalents thereof. Throughout the specification and the claims that follow, unless the context requires otherwise, the words "comprise" and "include" and variations such as "comprising" and 20 "including" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. -35- The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge. 5 - 36 -