JP2003055072A - Recycled fertilizer and soil conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recycled fertilizer which permits easy recycling of asbestos-containing building material wastes, is capable of making the asbestos known to be harmful to health absent, permits recycling of the wastes as a fertilizer and a soil conditioner and can assure not only a silica fertilizer as a fertilizer but also a soluble magnesium oxide as the mixed lime fertilizer and to provide a soil conditioner. SOLUTION: The asbestos is made absent by melting the wastes of the inorganic building materials containing the asbestos and the recycled silica fertilizer and the soil conditioner for replenishing silicic acid alkaline-component are obtained by utilizing the silicic acid, magnesium, etc., included in the wastes.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting a waste of an inorganic building material containing asbestos to obtain a recycled fertilizer and a soil conditioner without asbestos. It is. [0002] Asbestos-containing building materials such as chrysotile have been used as roofing materials and wall materials for residential and non-residential buildings for more than 30 years. No effective treatment has yet been established. For example, as a method for treating asbestos building material waste, only a treatment such as a final treatment of a large lump is performed. [0004] Building materials containing asbestos are left without an effective treatment method, and a concrete, effective and useful treatment method is desired. On the other hand, silicate fertilizers have attracted attention as useful fertilizers for increasing the silicidized cells of grasses, particularly rice, and increasing disease resistance, insect resistance, lodging resistance and the like. There is a need for fertilizers and soil conditioners that can replenish the alkali content to improve the affected soil. In the present invention, asbestos-containing inorganic building material waste is melted to make asbestos absent, and the silicic acid and magnesium contained in the waste are utilized. To obtain silicic acid-recycled fertilizer and a soil conditioner for replenishing silicic acid and alkali. DETAILED DESCRIPTION OF THE INVENTION The inorganic building material containing asbestos used in the present invention is an inorganic building material mainly composed of at least one of cement and calcium silicate and asbestos, and includes nickel, chromium and titanium. And almost no harmful components such as flat colored slate, corrugated slate, slate, calcium silicate board, slag gypsum board, and ceramic siding. In addition, these are premised on asbestos-containing roof and wall material waste generated mainly due to replacement or rebuilding, but naturally include those that are discarded without being used. In general, melting asbestos alone requires a heating temperature of 1500 ° C. or more, and it is difficult to melt asbestos using a conventional furnace. As a result, the melting temperature of asbestos can be lowered. In the present invention, waste of inorganic building materials containing asbestos is melted, and the waste often contains a silicate compound or an alkaline earth metal as a melting aid. Therefore, it is possible to melt at 1500 ° C. or lower. When the amount of the melting aid contained is small, it is also possible to lower the melting temperature by adding a melting aid, for example, a waste glass material. Of course, setting the melting temperature depends on the fuel cost,
It is determined in consideration of workability, equipment, and the like. There are various methods of melting, external heating electric furnace, arc furnace,
An electric furnace typified by a high-frequency heating furnace, a combustion gas furnace typified by a flat furnace, and the like. However, in consideration of fuel cost and the like, the waste may be crushed to a certain size and then fired. The time required for melting is not particularly limited, but it is sufficient that at least asbestos contained in the building material waste is melted, and is determined by the size, stacking method, chemical composition, and the like of the building material waste. After melting, the mixture is quenched or slowly cooled using water or the like. For example, when quenched using water, the melt is granulated to obtain granules. It is also possible. Of course, after slow cooling, pulverization, crushing, or the like may be performed in a subsequent step, or, if necessary, pulverization, crushing, or granulation may be performed in the next step to adjust the particle size. The obtained melt is free of asbestos, the soluble silicic acid and alkali are compatible with the silicic fertilizer of the official standard of ordinary fertilizers, and furthermore, the magnesium component, for example, include. For example, if lime is required, it can be adjusted by adding at least one of quick lime and slaked lime, and it is also possible to add an active ingredient of another fertilizer. It may be added during the granulation process to form a granulated product. (Example) Asbestos-containing building material waste (Colonial, trade name: composition in Table 1) was calcined at 1000 ° C. for 15 minutes, and then pulverized with a pin mill.
The mixture was heated at about 1500 ° C. for 30 minutes, melted, immediately put into water, rapidly cooled, and after the moisture of the rapidly cooled melt was removed, the mixture was ground in a pot mill for 4 hours. When the obtained powder was analyzed by fertilizer, as shown in Table 1, the alkali content was 35.2.
% And soluble silicic acid 26.2%, which were numerical values conforming to official standards as a siliceous fertilizer. Moreover, since soluble magnesia is 6.2%, it is a numerical value suitable as a mixed lime fertilizer that guarantees soluble magnesia. [Table 1] According to the present invention, asbestos-containing building material waste can be easily recycled, asbestos, which is said to be harmful to health, can be absent, and the waste can be used as a fertilizer or soil improvement material. The fertilizer is huge in demand because it can be recycled. The fertilizer has characteristics and effects such as not only silicate fertilizer but also soluble lime fertilizer as mixed lime fertilizer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C09K 101: 00 B09B 3/00 ZAB (72) Inventor Ryuichi Takahashi Ryoichi Takane, Yamagata Prefecture No. 1816 12 F term in IG Technical Research Institute Co., Ltd. (Reference) 4D004 AA31 AB10 BA02 BA04 CA04 CA14 CA29 CC13 4H026 CA01 CA03 CC06 4H061 AA01 CC13 DD14 EE42 FF07 GG23

Claims (1)

Claims: 1. A recycled fertilizer and a soil improving material obtained by melting an inorganic building material mainly composed of at least one of cement and calcium silicate and asbestos.