JPH08196820A - Dehydration of source slurry containing fine powder - Google Patents

Abstract

PURPOSE: To provide a stable treating process to separate a slurry suspending a fine powder therein into solid and liquid components and then to reuse the fine powder as a source material. CONSTITUTION: The pit P to be used has a weir wall and a bottom T comprising a porous powder layer having >=25% porosity and <=10mm grain size. A slurry suspending therein a fine powder of a smaller particle size than the pore diameter of the porous material is poured to the pit so that the fine powder in the slurry is trapped in the pores of the porous material to separate the solid from the liquid component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a solid / liquid separation of a slurry in which fine particles generated from a washing process of ores in a mining industry, a belt washing water in a belt conveyor for transporting ores, a wet dust collecting plant and the like are suspended. Furthermore, the present invention relates to a method for treating fine powder after solid / liquid separation.

[0002]

2. Description of the Related Art Conventionally, a process of washing ore in the mining industry, a belt washing water in a belt conveyor for transporting ores, a slurry in which fine powder generated from a wet dust collecting plant and the like are suspended is solid-liquid separated, When the fine powder obtained after liquid separation is used as a raw material or the like, after the fine powder is precipitated in a thickener, the precipitated portion is solid / liquid separated by a dehydrator such as a filter press so that it can be handled as a powder or granular material. This powder or granular material is used as a sintering raw material as it is or as a mixture with other raw materials.

On the other hand, when a vast space can be secured, a method is provided in which a pit surrounded by a dam constructed of concrete, earth and sand, etc. is provided, and a slurry in which fine powder is suspended is discharged and dried in the sun. It has been implemented.
Further, Japanese Patent Publication No. 53-4745 discloses that a dam provided around an outdoor raw material yard and a water collecting groove formed on the bottom floor by a granular layer of sand, gravel, etc. A technique is disclosed in which water is cleaned and discharged.

In the case of using fine powder ore or fine powder raw material, conventionally, a method of separating solid and liquid by using a dehydrating device such as a filter press and using fine powder as powder granules has been adopted. There is a problem that running costs are high. Further, since the fine powder raw material is solidified into a brick shape, when using the fine powder as a raw material,
There is a difficulty that requires a crushing process. On the other hand, when a pit surrounded by a dam built with concrete, earth and sand, etc. is provided, and the slurry is discharged into this pit and dried in the sun, it takes a minimum of about one week to dry, and it is vast. There is a problem that it requires a large space.

Further, as disclosed in the above Japanese Patent Publication No. 53-4745, the rainwater accumulated in the yard is cleaned and discharged by the water collecting groove formed on the bottom floor by the granular layer such as sand and gravel. Although this technique is excellent as a method for cleaning and discharging the water that has flowed out of the ore stack (mountain) that contains a large amount of water due to rainfall, etc.,
When applying this technique to solid-liquid separation of a slurry in which fine powder is suspended, the slurry flows into the water collection groove formed by the granular layer, and the fine powder in the slurry adheres to the voids in the granular layer. To do. This fine powder adhesion layer grows in accordance with the inflow amount of the slurry, and finally closes the voids of the granular layer. Therefore, this technique also has a problem in applying solid / liquid separation of a slurry in which fine powder is suspended, and further as a technique of utilizing a fine powder portion in the slurry.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and solid-liquid separates a slurry in which fine powder is suspended, and a stable treatment process in which fine powder can be reused as a raw material. The purpose is to provide.

[0007]

Means for Solving the Problems The gist of the present invention is that the porosity: 25% or more and average particle size (hereinafter simply referred to as particle size): 10 mm or less is used as a dam and a bottom floor. In the pit, a slurry in which fine powder having a particle diameter smaller than the pore diameter of the porous granular material is suspended is discharged,
A method for dehydrating a fine powder-containing raw material slurry in which fine powder in the slurry is adsorbed in pores of the porous granules for solid / liquid separation, and a porous granule layer having a porosity of 25% or more and a particle size of 10 mm or less In the pit that is the bottom floor,
A slurry in which fine powder having a particle size smaller than the pore diameter of the porous granules is suspended is discharged, and the fine powder in the slurry is adsorbed to the pores of the porous granules for solid / liquid separation to remove water. A method for dehydrating a fine powder raw material slurry in which pits are charged with porous granular materials having a porosity of 25% or more and a particle size of 10 mm or less in the state before solid / liquid separation are performed and mixed to obtain a raw material Furthermore, the present invention is a method for dehydrating a fine powder raw material slurry in which, after the slurry is discharged and dried, a porous granular material having a porosity of 25% or more and a particle size of 10 mm or less is charged and mixed.

[0008]

In the present invention, in order to separate fine powder and water in the slurry, that is, solid / liquid separation, porous granules having a porosity of 25% or more and a particle size of 10 mm or less, for example, sintered ore granules, are used as a dam and a bottom. Slurry is discharged into the pit where the floor was built and allowed to pass through the dam and bottom floor. According to the knowledge of the present inventors, when the particle size of the porous granules exceeds 10 mm, most of the fine powder in the slurry penetrates the granule layer. On the other hand, if the particle size of the granules is less than 1 mm,
Although the liquid separation is ensured, the granular layer is clogged in a short time by the fine powder in the slurry and becomes rapidly unfilterable. As shown in Table 1, the present inventors have tested granules having various particle size distributions and porosities as filter media. As a result, when the slurry is treated with granules having a particle size of 10 mm or less as filter media, fine powder in the slurry is obtained. It has been newly found that the resin can be filtered and collected and the clogging can be reduced.

[0009]

[Table 1]

Therefore, the particle size of the porous particles is 1 mm.
The above range is preferably 10 mm or less. When ordinary gravel or sand is used as a filter medium, a fine powder layer is formed on the surface (upper part) of the granular layer. When this fine powder layer is dried, it is fixed and dried in the sun to form a brick, which makes handling difficult when the fine powder is to be mixed with other raw materials so as to be used as the raw material. Further, when a fine powder is attached to the surface of the granules by forming the filtration layer with the granules having a particle size of 10 mm or less, a thick fine powder layer is formed on the surface of the granules. When the filtration layer is formed of particles having a porosity of 25% or more, fine powder is adsorbed by the pores on the surface of the particles, and a large amount of fine powder can be adsorbed on the surface of the particles without forming a thick fine powder layer.

However, it has been found that there is a problem in handling in the subsequent process. Therefore, as a result of many studies conducted by the present inventors, the idea of using a granular material having a large number of pores on the surface as a filter medium, as a result of performing a filtration test of a slurry in a granular form having various porosities, As shown in Table 1, it was found that it is necessary that the particles have a porosity of 25% or more. As the particles satisfying such conditions, for example, sintered ore particles obtained by sintering iron ore powder can be used. The particle size of the particles is preferably 1 mm or more and 10 mm or less, and the average particle size is preferably 3 to 5 mm.

Here, a pattern in which the fine powder in the slurry is adsorbed on the porous granules is shown in FIG. The relation between the pore diameter R of the porous granules and the fine powder particle diameter r in the slurry may be R> r, but it is preferable that r / R be 1/3 or less because the fine granules enter the pores of the porous granules. This is preferable because the fine powder particles can be reliably captured. Furthermore, when forming a pit by forming a dam and bottom floor with the granular layer and discharging the slurry into the pit for solid / liquid separation, the weight ratio of the granular particles and the slurry is 3: 1 or more. Must be When the ratio is 3: 1 or less, for example, the ratio of granules 1: slurry 1, part of the slurry cannot be captured in the granule layer after the slurry is discharged, and fine powder in the slurry adheres to the granule surface. The effect of this invention cannot be exerted.

In this way, as shown in FIG. 1, a pit P forming a dam H and a bottom floor T is constructed by a granular layer having a porosity of 25% or more and a grain size of 10 mm or less, and fine powder is formed in the pit. After the slurry for suspending the particles is discharged and the fine powder is adsorbed on the surface of the porous granular material, the granular material and the fine powder are mixed by, for example, a shovel loader and used as a sintering raw material or the like. In addition, even if a large amount of slurry in which fine powder is suspended is discharged into the pits and the slurry becomes turbid in the pits of the porous granules in a concentrated state, it is possible to newly add porous granules and mix them to form porous particles. Fine powder can be dispersed and adsorbed on the surface of the granular material to facilitate handling.
Furthermore, when newly loading the porous granules, the effect becomes more remarkable by using the dried porous granules.

[0014]

EXAMPLE Pit (length 20 m, width 10 m, pits) shown in FIG. 1 with the layers of the sintered ores shown in Examples 1 to 3 in Table 1 as one example.
1m) was built, and the lump ore used in the blast furnace was washed with water in this pit, and the average diameter of the lump ore adhering to 0.0
The slurry produced by removing the fine powder of 34 mm was discharged, and water was passed through the dam and the bottom floor for solid / liquid separation, and the fine powder in the slurry was attached to the pores of the sinter. By weight,
Slurry (fine powder 45: water 5
5) When the slurry was discharged into the pit P so that the ratio became 1, the water content was immediately filtered and the fine powder in the slurry was adsorbed on the surface and pores of the sinter. When the ratio of the sinter ore and the slurry was lowered, fine powder not adsorbed on the surface of the sinter and the pores began to be deposited in the pits P, and moisture remained.

That is, when the ratio of the sintered ore grains 3 to 3 was reduced to slurry 1, a fine powder deposit layer was formed in the pits P. By weight, 1 slurry for 3 sinter grains
The slurry was discharged so that the ratio became, and the fine powder deposited in the pit was mixed with the sintered ore layer used as the dam and the bottom floor using a shovel loader. By this, fine powder is adsorbed on the surface and pores of the sintered ore grain, and even after the fine powder is completely dried, it is adsorbed on the surface and pores of the sintered ore,
It was easy to handle and could be handled as a sintering raw material.

In Comparative Example 1, since the particle size is larger than 10 mm and the porosity is smaller than 25%, many fine powders in the slurry pass through the pit P together with water, and further, the fine powder capture rate is poor. Met. Comparative Example 2 has a particle size of 10
Since it was larger than mm, many fine powders in the slurry passed through the pit P, and the processing condition was bad. Comparative Example 3
Nos. 5 to 5 have a porosity of less than 25%, and the pore diameter is smaller than the fine powder diameter (0.14 mm). Therefore, the amount of fine powder trapped in the pore diameter is small, and a large amount of the concentrated slurry remains in the pit P. Drying and post-treatment required a great deal of time and effort. Further, many fine powders adhered to the surface of the sinter, and Comparative Example 4 was the worst. Thus, the fine powder could be filtered out from the slurry in which the fine powder was suspended under high productivity and used as a raw material for producing a sintered ore.

[0017]

As described above, according to the present invention, there is no need for dehydration equipment such as thickener and filter press as in the prior art, and a vast space such as in the case of sun drying. The water in the slurry is removed by passing through the dam and bottom floor formed by the porous granular layer, and fine powder is adsorbed and trapped in the pores of the porous granular body without any need for handling. The fine powder can be easily recovered, and can be used as a sintering raw material, for example.

Further, according to the invention of claim 2, the time for removing water after the slurry is discharged into the pit can be greatly shortened. Furthermore, according to the invention of claim 3, the time for removing water after the slurry is discharged into the pit can be further remarkably shortened, and the dehydration treatment capacity of the slurry can be greatly improved without requiring a vast space.

[Brief description of drawings]

FIG. 1 is a diagram showing a pit according to an embodiment of the present invention.

FIG. 2 is a view showing a pattern in which fine powder is adsorbed on the surface of porous particles and pores.

Continuation of the front page (72) Inventor Hidema Iwasaki No. 1 Nishinosu, Oita City, Oita Prefecture Shin-Nippon Steel Co., Ltd. Oita Steel Works premises Hamada Heavy Industries Co., Ltd. Oita Branch

Claims (3)

[Claims] 1. Porosity: 25% or more and particle size: 10 mm
A slurry in which fine powder having a particle diameter smaller than the pore diameter of the porous granules is supplied into a pit formed of the following porous granules, and the slurry is separated into solid and liquid. A method for dehydration treatment of a slurry containing fine powder material. 2. Porosity: 25% or more and particle size: 10 mm
After supplying a slurry in which fine powder having a particle size smaller than the pore diameter of the porous granular material is suspended in the pit formed by the following porous granular material, solid-liquid separation is performed in the pit. Previous porosity: 25% or more and particle size:
A dehydration treatment method for a fine powder-containing raw material slurry, characterized in that porous particles having a size of 10 mm or less are charged and mixed to obtain a raw material. 3. The dehydration of a fine powder raw material slurry according to claim 2, wherein the porous granular material having a porosity of 25% or more and a particle size of 10 mm or less in a state before solid / liquid separation is in a dry state. Processing method.