KR20150017054A

KR20150017054A - Method for separating nickel and fe from nickel irons

Info

Publication number: KR20150017054A
Application number: KR1020130092768A
Authority: KR
Inventors: 김현수; 박지욱; 조민영; 이춘선
Original assignee: 주식회사 포스코
Priority date: 2013-08-05
Filing date: 2013-08-05
Publication date: 2015-02-16

Abstract

A method for separating nickel and Fe from nickel ore is disclosed. The present invention provides a method for concentrating nickel by separating nickel and iron from nickel ore in a limonite ore form containing low content of nickel. The method for separating nickel and Fe from nickel ore according to the present invention comprises the steps of: preparing micro-granules by adding a material containing magnesium oxide to a limonite ore; sintering the micro-granules; reducing the sintered micro-granules; and crushing the reduced micro-granules and then carrying out magnetic separation on the micro granules.

Description

METHOD FOR SEPARATING NICKEL AND FE FROM NICKEL IRONS [0002]

The present invention relates to a method for separating nickel and iron from nickel ore and, more particularly, to a method for separating nickel and iron from nickel ore in the form of galena.

Nickel is a silver-white metal similar to iron. It is easy to process hot and cold and is safer and less oxidizable than iron in air or water. It is also resistant to neutral and alkaline as well as fresh water and seawater.

Nickel is an important component for the production of 300 series of stainless steels. The nickel component is mainly present in the ore layer present near the equator.

These ore layers are called nickel laterite deposits.

Nickelateite deposits are divided into five zones. The first zone is called the iron capping zone, which is the uppermost part of the latterite deposit. It is highly weathered and most of the nickel is not extracted.

Most are limonite and abandoned. The second zone is located just below the iron capping zone and is called the limonite zone. It is highly weathered and has small particle size and low nickel content.

The chemical composition is generally uniform, and nickel is mostly contained in the citrate. The nickel ore targeted in the present invention is directly present in this zone.

The content of nickel is as low as 0.5 to 1.5%, which is not economical to recover by melt reduction. Therefore, most of these ores use sulfuric acid extraction method. However, wet extraction methods using acid may cause serious environmental problems, so there may be many difficulties in applying them.

The third zone is the Intermediate zone between Limonite Zone and Saprolite Zone. The fourth zone is the Saprolite zone, which is found at the bottom of the Laterite deposits and has been moderately weathered.

Nickel exists as a mineral in the serpentinite, and its chemical composition and minerals are very heterogeneous. The nickel content in this area is higher than the ore in the Limonite zone so nickel can be extracted by dry method. Finally, the fifth zone is the lower bedrock.

The method of recovering nickel contained in the ore is dry and wet method, and the nickel in gray iron is advantageous in wet method and the nickel present in serpentine is advantageous in dry method.

There are five processes for treating nickel ore. First, the ore is charged into a rotary kiln or a vertical furnace by a Matte smelting process, heated under reducing conditions to produce a burned light, and then reacted with sulfur in an electric furnace to form Fe-Ni sulfide. The matte contains 30 to 35% of Ni. The air is sent to the converter to oxidize iron and sulfur and the final matte contains Ni 75-78%. Which is then refined to produce nickel of high purity.

The second process consists of drying and crushing the ore with Reduced Roast-ammonia Leach (Caron Process), followed by reduction and calcination, and then extracting and recovering nickel by using ammonia. This technology can recover 75% to 80% of Ni and 40% to 50% of Co. Nickel ore mainly in the form of metatarsophage is used.

When Ni ore in the form of serpentine rock with a low iron content and a high magnesium content is used, the Ni recovery amount is low.

In the third process, the ore is fired to remove moisture and crystal water by an electric furnace, and then charged into an electric furnace and melted and reduced at 1,550 ° C. This reaction produces an Fe-Ni melt containing about 25% Ni. This melt is refined to increase its purity.

In the fourth step, the ore is treated with high pressure extraction using sulfuric acid at 240 ~ 260 ℃ under pressure to separate Ni and Co from Fe. Compared to the Caron process, high pressure extraction is possible because sulfuric acid is used. Pressurization is beneficial for Ni and Co recovery as well as reduction and drying, and it is possible to recover more than 90%. This process is used for the treatment of nickel ore in the form of metapelite with a low Mg content.

Finally, nickel ore was preliminarily reduced and then melted and reduced in an electric furnace. Thus, the exhaust gas generated during the melting and reduction process was reused in the preliminary reduction process to increase the nickel recovery rate. Currently, it is widely used as a dry method.

In order to increase the recovery rate of Ni of laterite light, it is necessary to reduce Ni as much as possible in the preliminary reduction process, and in order to increase the value of product, the smaller the amount of Fe is, the better. However, since nickel oxide is more reductant than iron oxide, it is generated earlier than Fe. Therefore, it is difficult to separate Ni from Fe in practice.

If Fe and Ni can be separated, nickel can be extracted by the dry method of nickel light in the form of the maltite with low Ni content.

It is an object of the present invention to provide a method for concentrating nickel by separating nickel and iron from nickel ore having a low nickel content.

According to an aspect of the present invention, there is provided a method for separating nickel and iron from nickel ore according to an embodiment of the present invention includes the steps of preparing a micro-granule by adding a magnesium oxide-containing material to a limonite light, , Reducing the fired micro-granules, and screening the reduced micro-granules after crushing.

The magnesium oxide-containing material may be at least one selected from magnesite, serpentine, dolomite and nickel light melt reducing slag.

The firing may be performed using air at a temperature of 800 to 1,200 ° C. after charging the micro-granules into the fluidized bed reactor.

The reduction may be performed by blowing carbon monoxide or hydrogen into the fluidized bed reactor and reacting at 600 to 800 ° C.

The method for separating nickel and iron from nickel ore according to a preferred embodiment of the present invention includes the steps of preparing micro-granules by adding a magnesium oxide-containing material to limonite light, firing the micro-granules, Granulating a mixture of crushed micro-granules and coal, heating the compacted granules of micro-granules and coal to separate nickel-enriched slag and molten iron And sorting the nickel-enriched slag after crushing.

The compacted material may be heated in a rotary kiln or a rotary hearth furnace at a temperature ranging from 1,250 ° C to 1,500 ° C.

According to the method for separating nickel and iron from nickel ore according to the present invention, iron and nickel are separated from the ore-shaped nickel ore having a low nickel content. Iron is used in the process of manufacturing molten iron, and the separated nickel is concentrated in the slag, The nickel can be effectively recovered by the recovery process.

1 is a process diagram of a method for separating nickel and iron from nickel ore according to an embodiment of the present invention.
FIG. 2 is a graph showing the distribution of metal ions when fired hematite, nickel oxide, and magnesium oxide were mixed at 1,150 ° C. for 24 hours.
3 is a process diagram of a method for separating nickel and iron from nickel ore according to another embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described in detail below. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. Like reference numerals refer to like elements throughout the specification.

Referring to FIG. 1, a method of separating nickel and iron from nickel ore according to an embodiment of the present invention includes the steps of preparing micro-granules by adding magnesium oxide-containing material to limonite light, , Reducing the fired micro-granules, and screening the reduced micro-granules after crushing.

The limonite light is a talc-type nickel light having a low nickel content of 0.5-1.5%. Magnesite, serpentine, dolomite and nickel light melt reducing slag may be used as the material containing magnesium oxide (MgO).

The reason for adding the magnesium oxide-containing substance to the limonite light, which is one of the main technical features of the present invention, is as follows.

It is known that the Ni ² ⁺ and Mg ² ⁺ ions are similar in size, and when the ratio of MgO is increased, Ni ² ⁺ substitutes for Mg ² ⁺ , thereby reducing the reducing power of Ni ² ⁺ . Therefore, nickel ore in the form of serpentine rock with a high magnesium oxide (MgO) content should be subjected to a hot melt reduction method for nickel extraction.

Nickel ore in the form of serpentinite with a high magnesium oxide content is decomposed at over 800 ℃ and recrystallized into olivine. When such a form is obtained, the nickel contained therein becomes very poor in reducing property.

However, in the case of nickel ore with a low content of nickel, most of the nickel is contained in the citrate. When the ore is calcined, crystal water attached to the citrate is removed and nickel oxide is exposed on the surface.

In this case, the nickel reducing property by the gas becomes very high. As a result, Fe and Ni are reduced, forming a solid solution phase, and nickel separation may be difficult. In order to solve this problem, it is possible to consider a method of separating Ni and Fe by converting galena-type nickel light into serpentine-type nickel light.

That is, a substance containing a large amount of MgO or MgO is added to the nickel ore in the form of metapelite to move Ni to MgO. If this happens, Ni can be concentrated in MgO and converted to olivine form, reducing the reductivity.

In other words, iron (Fe) is easy to reduce, but nickel can not be reduced, and it becomes possible to concentrate into gangue or slag in oxide form. This compound can be broken up and iron and gangue or slag can be separated through the magnet. Iron is magnetically separated and can be used in the process of manufacturing molten iron after it is separated by magnetic force. Slag that is enriched with nickel can be melted and reduced in electric furnace to recover nickel, which makes it possible to produce nickel-rich product.

A micro-granule is prepared by mixing the limonite light and the magnesium oxide-containing material. The smaller the size of the micro-granules, the better the heat transfer and the better the firing and reduction, so that the size of the micro-granules is preferably 1 mm or less.

The micro-granules are then subjected to a sintering process in the temperature range of 800 to 1200 ° C. As the firing reactor, a fluidized-bed reactor is suitable. At this time, the nickel ion migrates to magnesium oxide (MgO), and the activity is lowered and isolated.

2 shows the distribution of metal ions when calcined at 1,150 占 폚 for 24 hours by mixing hematite, nickel oxide and magnesium oxide (MgO). It can be seen that the distribution of nickel and nickel is the same, so that the nickel migrated to the magnesium oxide considerably.

As described above, it can be seen that nickel concentration is possible through firing. After the firing process, the micro-granules maintain adequate strength. Therefore, it is possible to reduce the gas using a fluidized bed reactor. For gas reduction, hydrogen gas, carbon monoxide (CO) gas, or a mixed gas of hydrogen and carbon monoxide can be used.

The reaction temperature is 600 to 800 ° C. At a temperature higher than 800 ° C, concentrated nickel oxide (NiO) in the slag may be oxidized or coagulated between micro-granules during reduction.

The reduced micro-granules undergo a crushing process. Reduced Fe is magnetically separated and slag and gangue with enriched nickel are not magnetic and can be separated by magnetic force selection. The separated Fe can be utilized in the process of manufacturing molten iron, and the separated slag can be utilized in the nickel recovery process and the melting reduction process using the electric furnace.

Referring to FIG. 3, a method of separating nickel and iron from nickel ore according to another embodiment of the present invention includes the steps of preparing micro-granules by adding magnesium oxide-containing material to limonite light, Granulating the mixture of fired micro-granules and coal, heating the compacted granules of micro-granules and coal to obtain a slag containing nickel-enriched slag And a step of separating the nickel-enriched slag after crushing the magnetic force.

Up to the step of calcining the micro-granules, which is a main feature of the present invention, the same as described above, and the following additional technical features will be described.

The fired micro-granules are mixed and crushed with coal in the powder. Subsequently, an inorganic or organic binder is added to the mixture of the crushed micro-granules and coal to agglomerate. The binder may be a generally known general-purpose binder.

The agglomerator may be a hot briquette or a room temperature briquetting apparatus. Nickel-agglomerated light in the massive carbonaceous material is heated using a rotary kiln or a rotary washer furnace.

When nickel compact light is heated in the furnace to 1,250 ° C to 1,500 ° C, the carbon of the carbonaceous material and the iron oxide of the nickel ore are reacted to generate a reducing reaction. At the same time, the carburized reaction occurs in the reduced iron, .

Since the surface tension of molten iron is as high as 2.0 N / m and the size of the molten iron droplet gradually increases, it becomes possible to separate iron (Fe) and slag. The adhesion between the slag and the molten iron is small, so that a simple crushing process, that is, separation of the iron and the slag can be performed even with slight fluctuation.

The content of nickel in the slag may vary depending on the iron (Fe) content and the content of magnesium oxide (MgO) mixed in the ore, but it is possible to concentrate about twice the nickel content contained in the calcite.

That is, it is possible to concentrate 1% ~ 3% when the content of nickel is 0.5% ~ 1.5% in the maltite-type nickel light. Slag and iron can be selected through magnetic force, and the selected iron (Fe) can be used in the process of manufacturing molten iron, and the nickel-enriched slag can be used to manufacture nickel through a melting and reduction process using an electric furnace.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims

Preparing a micro-granule by adding a magnesium oxide-containing substance to the limonite light;
Calcining the micro-granules;
Reducing the fired micro-granules; And
A method for separating nickel and iron from a nickel ore comprising the step of magnetically separating the reduced micro-granules after crushing.

The method according to claim 1,
Wherein the magnesium oxide-containing material is at least one selected from the group consisting of magnesite, serpentinite, dolomite, and nickel light melt reducing slag.

3. The method of claim 2,
Wherein the calcination is performed using air at 800 to 1,200 DEG C after micro-granules are charged into a fluidized bed reactor.

The method of claim 3,
Wherein the reduction is carried out by introducing carbon monoxide or hydrogen into the fluidized bed reactor and reacting the mixture at 600 to 800 占 폚.

Preparing a micro-granule by adding a magnesium oxide-containing substance to the limonite light;
Calcining the micro-granules;
Mixing the calcined micro-granules and pulverulent coal followed by pulverization;
Agglomerating a mixture of crushed micro-granules and coal;
Heating the compacted material of the micro-granules and the coal to separate the slag and the molten iron into nickel-enriched slag; And
And separating the nickel and iron from the nickel ore containing the nickel-enriched slag.

6. The method of claim 5,
Wherein the compacted material is heated in a rotary kiln or a rotary hearth furnace at a temperature ranging from 1,250 ° C to 1,500 ° C.