JP2008106328A - Method for granulating powdery substance and granulated product thereof - Google Patents

Abstract

[Problem] To provide a method and a granulated product thereof capable of appropriately granulating or agglomerating a powdery substance in which sulfuric acid is independently present even when a relatively small amount of a binder is added.
SOLUTION: A method of making a powdery substance in which at least sulfuric acid exists independently into a granular or agglomerated form, adding a calcium compound and a powdery organic binder to the powdery substance and kneading the powdery substance. The kneaded product is granulated into a granular or lump shape having a particle diameter of 10 to 200 mm by a granulator.
[Selection] Figure 1

Description

The present invention relates to a method for granulating or granulating a powdery substance in which at least sulfuric acid exists independently, and a granulated product thereof.

In recent years, as a method for granulating this kind of powdery material, a method for producing waste briquettes for smelting furnaces that can contribute to stabilizing the furnace conditions of smelting furnaces with excellent hot strength and can be produced at low cost. In this method, a powdered granular material containing a metal component and a binder are kneaded, the kneaded kneaded product is formed into briquettes, and the formed briquettes are naturally cured (Patent Document 1) or dissolved. A method for producing briquettes having excellent moldability and high reducibility in molding and reduction treatment of dust collection dust generated from a furnace and a smelting furnace, wherein 1 to 10% by weight of plastic and lime component are contained in the dust collection dust 5 to 30% by weight, and carbon material 5 to 20% by weight. There exists what knead | mixes and shape | molds (patent document 2).
JP 2006-265617 A JP 2005-248235 A

Then, it tried to apply the granulation method of the above-mentioned powdery substance to make the powdery substance in which at least sulfuric acid exists independently into a granular form or a lump. However, with the former method of granulating a powdery substance, the hot strength of the briquette formed is weak, and with the latter method of granulating a powdery substance, a large amount of viscosity is required to obtain the required hot strength. There were problems such as the need for a binder.

The present invention has been made in view of the above circumstances, and its purpose is to accurately form a powdery substance in which sulfuric acid exists independently even in the addition of a relatively small amount of a binder. It is to provide a possible method and its granulate.

In order to achieve the above object, the granulating method of the powdery substance in the present invention is a method of granulating or lumping the powdery substance in which at least sulfuric acid exists independently, and the powdery substance contains a calcium compound. And a powdery organic binder are added and kneaded, and the kneaded product thus obtained is granulated into granules or lumps having a particle diameter of 10 to 200 mm by a granulator.

In such a structure, the sulfuric acid content of the powdery substance in which sulfuric acid exists independently and calcium react with each other to produce calcium sulfate, so-called gypsum, and the sulfuric acid content disappears. Along with this, since the rapid oxidation phenomenon of sulfuric acid does not occur in the high temperature atmosphere, the binding force of the organic binder is maintained, and as a result, the granulated product is suppressed in strength reduction under the high temperature atmosphere and is generated. Gypsum contributes as a binder for increasing the hot strength, and can maintain a grain or lump state in a high temperature atmosphere of 400 to 550 ° C.

In the present invention, examples of the powdery substance in which at least sulfuric acid exists independently include lead sulfate powder and lead carbonate powder obtained by adding sulfuric acid.
In the present invention, the calcium compound is any one of slaked lime, lime, quicklime, calcium carbonate, calcium sulfate, and calcium fluoride. In the present invention, the powdered organic binder is starch, dextrin. , One of lignin.
In addition, in the present invention, some granulators form briquette machines, tablets, pellets and the like.

As is apparent from the above description, the present invention is a method for making a powdery substance in which at least sulfuric acid exists independently into a granular or agglomerated form, wherein the powdery substance is combined with a calcium compound and a powdery organic caking. Since the kneaded product thus obtained is granulated into a granular or lump with a particle size of 10 to 200 mm by a granulator, the sulfuric acid content of calcium and calcium react with each other to produce gypsum. In addition, since the sulfuric acid content disappears and the binding force of the organic binder is maintained, the granulated product is granulated or lump in a high temperature atmosphere of 400 to 550 ° C. for 10 to 30 minutes. Excellent practical effects such as being able to have high hot strength to maintain

Hereinafter, the method for granulating a powdery material according to the present invention will be described in detail using the powdered material granulation facility shown in FIG. As a powdery substance in which at least sulfuric acid is present independently, a required amount of powdered lead sulfate is introduced from the hopper 1 into the kneading machine 2 (MSG05, manufactured by Shinto Kogyo Co., Ltd.). Slaked lime, starch as a powdery organic binder, and water are respectively added and kneaded, and the kneaded material thus obtained is temporarily stored in the intermediate hopper 3 and then cut out by the belt conveyor 4 as a granulator. The briquette machine 5 (BMS-2 manufactured by Shinto Kogyo Co., Ltd.) is granulated into a lump by the briquette machine 5.

In the granulation facility for the present powdery substance, the lump is conveyed to the vibrating sieve 7 by the belt conveyor 6 and sieved, and then conveyed to the product yard 9 by the belt conveyor 8.
Table 1 shows the results of measuring the strength at that time after allowing the granulated mass to stand for one day and then placing it in a high temperature atmosphere of 500 ° C. for 20 minutes.

In addition, Table 2 shows the results of measuring the strength at every heating elapsed time in a high temperature atmosphere at a temperature of 500 ° C. after leaving the lump granulated under the conditions of Test 4 in Table 1 for one day.
In other words, Table 2 shows data obtained by examining the time during which the lump can suppress the strength reduction in a high temperature atmosphere.

Table 1 shows the following. That is, the strength of the lump of powdered lead sulfate was remarkably increased, and there was little damage even when dropped onto the steel plate from a height of 2 m immediately after the lump formation, and the crushing strength after 1 day was about 43 kg. As a result, the lump could be stored without breaking up to a height of 10 m, and was hardly damaged during transportation. Furthermore, from Table 2, it was found that there was little decrease in strength until 30 minutes.

It is a schematic diagram of the granulation equipment of the powdery substance for implementing this invention.

Claims (6)

A method of making a powdery substance in which at least sulfuric acid exists independently into a granular shape or a lump, wherein a calcium compound and a powdery organic binder are added to the powdery substance and kneaded, and a kneaded product thus obtained is obtained. A method for granulating a powdery substance, characterized in that it is granulated into a granule or lump having a particle diameter of 10 to 200 mm by a granulator. 2. The method for granulating a powdery substance according to claim 1, wherein the powdery substance is a lead sulfate powder. In the granulation method of the powdery substance according to any one of claims 1 to 3,
The said calcium compound is any one of slaked lime, lime, quicklime, calcium carbonate, calcium sulfate, and calcium fluoride, The granulation method of the powdery substance characterized by the above-mentioned. In the granulation method of the powdery substance according to any one of claims 1 to 4,
The powdery organic binder is any one of starch, dextrin, and lignin. A substance obtained by granulating or lumping a powdery substance in which at least sulfuric acid exists independently,
A granulated product, wherein the kneaded product of the powdery substance, calcium compound and organic binder is granulated into a granular or lump shape having a particle size of 10 to 200 mm by a granulator. The granulated product according to claim 6, wherein the powdery substance is a lead sulfate powder.