KR101528043B1 - Method for Fabricating Byproduct from Nickel Extraction - Google Patents

Abstract

The present invention relates to a method for recovering iron ores and acids from wastes generated in a precipitation process of a nickel hydrometallurgical process, and more particularly, to a method for recovering nickel from a nickel ore containing nickel and iron, A method for recovering a by-product of a nickel-based wet smelting process for recovering a by-product from an aqueous solution containing chloride ions, alkali metal ions and iron ions discharged after recovering the nickel in a smelting process, characterized in that the aqueous solution is evaporated and crystallized A crystallization step; And a roasting step of subjecting the crystallized iron chloride to solid-liquid separation, roasting, and pyrolysis with iron oxide and chlorine.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for recovering by-

The present invention relates to a method for recovering iron ores and acids from wastes generated in a precipitation process of a nickel wet smelting process including hydrogen reduction, acid leaching and precipitation, and more particularly, And a method for recovering iron ores and acids by crystallizing and roasting an aqueous solution by evaporation and concentration.

Nickel-containing ores include limonite, saprolite, and ore. These ores have passive properties, so they are highly resistant to acids, so acid dissolution is slow. As a method for effectively leaching nickel, there have been proposed methods for recovering nickel by dissolving the acid in an autoclave under high temperature and high pressure, and this is called 'HPAL (High Pressure Acid Leaching) method'.

When the nickel leaching reaction is carried out at room temperature, the nickel recovery rate does not exceed 85% even after leaching for several months or longer. However, when the HPAL method is used, leaching of nickel at 90% or more is possible within 2 hours, .

Examples of techniques for recovering nickel by the HPAL method include Korean Patent Laid-Open Publication No. 2007-7020915 and Japanese Laid-Open Patent Publication No. 2010-031341. However, it is known that the HPAL method should be performed under high temperature and high pressure of the autoclave, and it is known that only the titanium material can be mainly used due to its strong acidity, and accordingly, the equipment cost is very high and the maintenance cost is high. In addition, the use of caustic soda, which is an expensive precipitant, or the use of an environmentally harmful precipitant (H ₂ S) is required to concentrate nickel, and thus there is a problem in that the equipment cost for treating such a problem is increased.

On the other hand, the present inventors have proposed a method for recovering nickel from nickel ore by acid leaching after hydrogen reduction of a nickel-containing raw material in Korean Patent Laid-Open Publication No. 2009-0031321. In the technique of the patent document, V and Mo are recovered from a petrochemical desulfurization spent catalyst and the remaining residue is treated with an acid to remove alkali elements in the residue; Drying the residue from which the alkali element has been removed, and then performing a heat treatment in a reducing atmosphere at a temperature range of 600-1300 캜 to reduce Ni and Fe existing in an oxide form in the residue to a metal; Leaching the reduced product obtained in the above step with an acid to selectively dissolve iron and nickel; Filtering the solution to obtain leached nickel and iron ion-containing solution; Neutralizing the solution containing Ni and Fe ions with alkali to make Fe and Ni hydroxide; And a step of filtering and drying the product obtained in the above step to obtain Fe and Ni-containing raw materials, and a method for producing iron nickel-containing raw materials from petrochemical desulfurization spent catalyst recycled residues.

However, during such a nickel smelting process, a large amount of waste is generated and discharged, and waste treatment is required, which requires additional cost.

Accordingly, the present inventors have proposed a method for minimizing the waste generated during the process by recovering effective resources from wastes generated during the nickel smelting process in Korean Patent Laid-Open Publication No. 2013-0076556. According to this method, there is provided a method for treating waste generated during a nickel wet smelting process in which nickel ions are leached from a leaching light for leaching, and iron in the ore is substituted with nickel to recover nickel by adding precipitation reducing light, Removing the ferronickel metal to obtain a Fe ion-containing solution; And adding a Ca-containing alkali agent to the iron ion-containing solution, and introducing air to oxidize the iron, thereby producing magnetite. However, this method is disadvantageous in that the amount of gypsum generated is large and the amount of total by - products is increased.

The present invention seeks to provide a method for minimizing the generation of waste by obtaining iron oxide from an iron ion-containing solution generated after nickel precipitation in a nickel smelting process and regenerating the used acid during the process.

On the other hand, the problem that alkaline chloride generated in the ore or in the nickel smelting process is introduced into the iron oxide by the alkali component is lowered to deteriorate the quality of the iron ore, thereby obtaining high-quality iron chloride and recovering hydrochloric acid in a high yield Method.

The present invention also provides a method for reducing the evaporation cost by reusing steam generated during the process of the present invention.

The present invention relates to a method for recovering effective resources from process wastes generated in a wet smelting process of nickel, comprising: a nickel wet smelting process for recovering nickel from an ore containing nickel and iron using an acid solution containing chlorine And recovering by-product from an aqueous solution containing alkali metal chloride and iron chloride which is discharged after recovering the nickel in the step (a), the method comprising: a crystallization step of crystallizing the iron chloride by evaporating the aqueous solution to crystallize the iron chloride; And a roasting step of subjecting the crystallized iron chloride to solid-liquid separation, roasting, and pyrolysis with iron oxide and chlorine, and recovering by-product of the nickel wet smelting process generated during the nickel wet smelting process.

As another embodiment, the method may further include a washing step of washing the crystallized iron chloride with an aqueous solution saturated with ferric chloride to remove alkali ions.

The roasting step may be roasted by spraying the crystallized iron chloride after aqueous solution.

At this time, the alkali ion is selected from the group consisting of Na, K and Ca, and any one of them may be singly used or a mixture of two or more thereof.

The crystallized iron chloride can be obtained by heating an aqueous solution of iron chloride to evaporate and concentrate, and can be obtained by heating under vacuum and concentrating by evaporation.

The roasting temperature of the crystallization roasting may be 400 ° C or higher, and the roasting temperature of the solution roasting may be 600-900 ° C.

The chlorine gas discharged in the roasting step may be recovered as hydrochloric acid by water.

In addition, the aqueous solution of iron chloride can be evaporated using the steam evaporated in the crystallization step, and the steam can be used by heating or pressurizing.

Meanwhile, the nickel wet smelting process includes a leaching step of dissolving nickel ore containing Ni and Fe in hydrochloric acid to obtain a leached solution containing Ni and Fe ions; Adjusting the pH by adding an alkaline agent to the obtained leach solution, and removing the solid impurities from the leach solution by solid-liquid separation; A step of adding nickel ore containing Ni and Fe to the leach solution and then precipitating nickel into ferronickel to recover ferronickel; And a precipitate recovering step of separating the solid precipitate from the precipitation liquid to recover and recover solid precipitate.

At this time, the alkaline agent may be added so that the pH of the leach solution is 1.5 to 3.5, and the alkali agent may be a metal hydroxide selected from the group consisting of Mg, Fe, Ni, Mn, Na, K and Ca, Lt; / RTI >

Meanwhile, the leaching solution in the leaching step may be a residue of nickel ore dissolved in hydrochloric acid.

According to one embodiment of the present invention, iron oxide can be recovered from a waste iron chloride solution generated during the nickel smelting process, and the acid used during the process can be recovered and reused in the process.

According to an embodiment of the present invention, it is possible to reduce the incorporation of alkali ions into the iron chloride crystals by crystallizing the iron chloride from the iron chloride waste generated during the nickel smelting process and providing the iron chloride to the roasting, The recovery rate of hydrochloric acid can be improved.

Further, in the crystallization of iron chloride, steam can be used as crystallization energy by using steam evaporated during evaporation, and energy can be saved, and steam can be recycled by heating or pressurizing the surplus steam, thereby saving energy compared to spray roasting Is possible.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for recovering byproducts from wastes generated during a nickel wet smelting process, and more particularly, to a process for recovering byproducts from waste wastes generated during a nickel wet smelting process, ) And a method for recovering hydrochloric acid.

In one embodiment of the present invention, the nickel ore to which the nickel hydrometallurgical process is applied is not particularly limited, and for example, ores including nickel and iron such as limonite and saproproite may be used.

The nickel wet smelting process is a process of dissolving nickel from a nickel ore containing nickel and iron with a chloride ion-containing acid solution such as hydrochloric acid and then precipitating with ferronickel to recover nickel. After recovering the nickel, iron chloride and alkali metal chloride The present invention can be applied as long as it is a process by-product. For example, but not exclusively, it includes a step of leaching iron and nickel into an acid after reduction of nickel ore, and a step of concentrating and recovering nickel by a step of precipitating nickel ions in the leaching solution by a displacement precipitation reaction can do.

First, it includes a step of reducing the nickel ore. Hydrogen is used as a reducing agent, and it is not particularly limited as long as it is a gas containing hydrogen. When the hydrogen-containing gas is used as the reducing gas, the reduction process can be performed at a relatively low temperature as compared with the case of using carbon. In addition, nickel metal having a specific surface area of 1-100 m 2 / g can be produced with a high activity, whereby it can be easily dissolved by an acid, so that a subsequent acid leaching process can be carried out at high speed.

As such a reducing gas, a gas containing hydrogen can be used. Preferably, hydrogen may be used alone, or an inert gas may be used together. The inert gas may be included to remove oxygen other than hydrogen present in the reducing furnace during the reduction reaction. Such an inert gas is not particularly limited as long as it is not reactive, and examples thereof include helium, argon, carbon dioxide, nitrogen and the like.

Further, another example that can be used as the hydrogen-containing reducing gas is a gas generated from a coke oven gas (COG) containing 50% or more of hydrogen generated in the iron ore smelting process or a methane hydrogen reforming reaction, And hydrogen-containing LNG reforming gas containing 65% or more of hydrogen.

The reduction step may be performed in a temperature range of 725-950 DEG C using hydrogen as a reducing agent to reduce metal oxides such as iron and nickel in the nickel ore. The nickel ore reduced by such a reaction can be obtained. Hereinafter, the reduced nickel ore is also referred to as 'reduction light'. For convenience, the reduction light used in the leaching step according to the process in which the reduction light is used is referred to as 'leaching reduction light', and the reduction light used in the precipitation step is referred to as 'leaching reduction light'.

The exhaust gas obtained in the reduction step is separated and discharged. The reducing light is converted into a slurry by using water, and then an acid is added to the slurry to thereby carry out a leaching step of dissolving iron and nickel in the ore. Nickel and iron contained in the reducing material in the slurry are dissolved by the acid and leached into the ions.

As the acid which can be used in the leaching step, hydrochloric acid, sulfuric acid and the like can be used, but hydrochloric acid is preferably used for recovery of iron and acid from the waste liquid discharged after nickel precipitation.

On the other hand, the nickel ore contains Al ₂ O ₃ , SiO ₂ , Cr ₂ O ₃ and the like. These components rarely dissolve by the acid in the leaching reaction step and remain mostly as solid residue, And eluted into the leach solution. However, since the Al, Si, and Cr components are elements capable of causing deterioration of precipitation efficiency of nickel in the subsequent precipitation step, it is preferable that these components are removed from the leach solution before the precipitation step.

The Al, Si and Cr components dissolved in the leaching solution can be precipitated and removed by forming a solid hydroxide by changing the pH of the leaching solution by adding an alkaline agent to the leaching solution. As a result, the precipitate filtrate becomes a sludge containing a solid-phase hydroxide, and a solid content is removed by means such as filtration to obtain an extract liquid containing no Al, Si and Cr components.

The content of the alkaline agent added to the above-mentioned leach solution is not particularly limited, but it is preferable that the pH of the leachate is adjusted to a range of 1.5 to 3.5. The pH of the precipitation filtrate obtained by the acid added during the leaching reaction has a very high acidity, usually 1 or less. By controlling the pH to the above range, the Al, Si and Cr components present in the solution can be effectively removed. However, when the pH of the precipitation filtrate exceeds 3.5, the iron ions in the solution are also converted into hydroxides, which may result in lowered iron recovery. It is more preferable that the pH does not exceed 3.5.

At this time, the alkaline agent may be added before removing the leaching residue from the leaching solution to convert the leaching residue and the hydroxide together after the conversion to the hydroxide, as well as removing the leaching residue by solid-liquid separation from the leaching solution, To form a sludge, which is then filtered to obtain a pH-controlled leach solution.

At this time, the alkaline agent to be added for controlling the pH of the above-mentioned leaching solution is not particularly limited and can be used without limitation as long as it can raise the pH of the leaching solution. For example, hydroxides of metals such as Na, K, Ca, Mg, Fe, Mn, or Ni. They may be used alone or as a mixture.

When the precipitation-reducing light is supplied to the leaching solution obtained by the leaching reaction, nickel ions in the leaching solution are replaced with iron ions in the reducing light to precipitate as ferro-nickel deposits by the reaction shown in the following formula (1) Reacts with chlorine to form iron chloride.

Therefore, the precipitate of ferronickel can be recovered by solid-liquid separation such as filtration from the precipitation liquid containing the precipitate obtained by the precipitation reaction.

Nickel can be precipitated by the substitution reaction of the nickel ions in the leaching solution and the iron ions in the reducing light by adding the reducing light to the leaching solution thus obtained. As a result, a precipitate of the ferronicky form can be obtained, and precipitates of the ferronickel can be obtained by recovering the precipitate from the solution by solid-liquid separation.

On the other hand, the precipitation filtrate remaining after recovering the precipitate is an iron chloride aqueous solution containing iron chloride. The precipitation filtrate can be separated into iron oxide and chlorine gas by pyrolysis of iron chloride by roasting in the roasting furnace, Can be obtained.

As described above, the alkaline agent added for adjusting the pH of the leach solution may be used without limitation. However, the Na, K, or Ca ions contained in the alkaline agent or nickel ore added to the pH of the leach solution, dissolved in the acid by the acid, react with the chloride ion in the aqueous solution of the iron chloride to produce NaCl, KCl, CaCl ₂ and the like. Unlike the chlorides of other alkali agents, these chlorides such as NaCl, KCl and CaCl ₂ do not undergo thermal decomposition even during the roasting process to recover iron ores and acids, so that hydrochloric acid is not recovered, It is mixed with iron oxide to increase the Cl concentration of the iron oxide product so that the quality of the iron oxide is remarkably lowered so that it can not be recycled as iron ore.

Therefore, it is necessary to prevent the chlorides of Na, K and Ca from being mixed into the iron oxide to improve the quality of the iron oxide. In order to obtain a high-quality iron oxide free from the incorporation of an alkali chloride, iron chloride is obtained from the precipitation filtrate as a crystal and subjected to solid-liquid separation by filtration or the like to obtain chloride chloride from which the chlorides of Na, K and Ca have been removed. The high-purity iron oxide can be obtained.

Specifically, in order to remove the alkali chloride present in the aqueous solution of iron chloride, the aqueous solution of iron chloride is concentrated by evaporation to the solubility of the iron chloride or higher to obtain the green colored ferric chloride crystals.

The crystallization of iron chloride can induce crystallization of iron chloride from an aqueous solution of iron chloride by heating the precipitation filtrate to high temperature to evaporate water and concentrate the precipitation filtrate. At this time, if the crystallization temperature is high, the 2-hydrate (2H ₂ O) crystallizes in the state having the crystal number, and when the crystallization temperature is low as in the case of heating in the vacuum state, the 4-hydrate (4H ₂ O ) Can be obtained.

As described above, in the crystallization of iron chloride, steam can be used as crystallization energy by using steam evaporated during evaporation and concentration, energy can be saved, steam can be recycled by heating or pressurizing the surplus steam, Energy can be reduced.

The iron chloride is solidified by the crystallization of the iron chloride by such evaporation concentration, but most of the alkali ion present in the solution exists in the ion state. Therefore, it is possible to separate the iron chloride crystals from the precipitation filtrate by a solid-liquid separation means such as filtration. As a result, a highly pure iron chloride crystal can be obtained.

Alkali ions, particularly Na, K and Ca components, can be removed from the iron chloride crystals obtained by such a method, but alkaline ions are added to the surface of the iron chloride crystals because the alkali ions are concentrated in the solution. Therefore, it is more preferable to obtain higher quality iron oxide by removing the alkali ions adhering to the crystal surface.

In order to remove the alkali ions adhering to the surface of the iron chloride crystals, some of the adhered alkali ions can be removed from the surface of the iron chloride crystals by washing the iron chloride crystals using a saturated solution of iron chloride in which the high purity chloride is dissolved at a saturated concentration.

Iron chloride and chlorine gas can be obtained by pyrolyzing the solid phase high-purity iron chloride crystals obtained by the above-mentioned method by crystallization roasting which roasts. This can be expressed by the following equation (2).

The pyrolysis reaction may be performed at a temperature of 400 ° C or higher. On the other hand, the upper limit of the roasting temperature can be suitably set in accordance with the operating temperature range of the roasting furnace and the like, and is not particularly limited. However, it is preferable to set the temperature to 800 DEG C or less from the viewpoint of economical efficiency such as energy consumption required for roasting.

On the other hand, the iron chloride crystals may be formed into iron oxide and chlorine by solution roasting in which the iron chloride crystals are dissolved in water, rehydrated and dissolved, and sprayed to a roasting furnace. However, such solution roasting is capable of pyrolyzing pyrolysis at a roasting temperature of about 600-900 ° C.

From the viewpoint of reducing the energy cost as described above, crystallization roasting is more preferable. Further, when the solution is roasted, fine iron oxide powder having a fine particle size is obtained. In this case, an additional process for pelletizing the fine powder for utilization in the industry is required, for example, by introducing the obtained iron oxide into an electric furnace. However, iron oxide obtained by crystallization roasting can be obtained in the form of granules having a large particle size, which is more preferable from the viewpoint of not requiring an additional pelletization step.

The iron oxide obtained by roasting may be recovered in the form of solid phase powder using a dust collector or the like. On the other hand, chlorine is discharged together with the flue gas in a gaseous state, and hydrochloric acid can be obtained by passing water through the flue gas.

Iron oxide and hydrochloric acid can be recovered from the waste iron chloride solution generated during the wet smelting process of nickel from nickel ore by the above-described method.

Hereinafter, the present invention will be described in more detail by way of examples, but the following examples are illustrative of one embodiment of the present invention and are not intended to limit the present invention.

Example

Manufacturing example

The limonite ore was dried in a rotary kiln furnace maintained at 200 ° C and then pulverized by a roll mill to obtain a powder having an average particle size of 2 mm or less. The obtained limonite ore powder was calcined at 600 ° C for 2 hours to prepare a nickel ore powder.

The prepared ore was reduced at 750 ° C to prepare 100 g of reduced light.

The thus-prepared reduced light was cooled in an oxygen-free tank filled with nitrogen gas, and 85 ml of water was added to 85 g of the reduced light to prepare a slurry.

To the slurry prepared above, 20% hydrochloric acid was added to the slurry to make a 1-liter solution. The solution was stirred at the solution temperature of 25 ° C to dissolve the reducing light, and an acid leaching reaction was performed to leach nickel and iron ions from the reducing light. The pH of the leached acid solution (leach solution) was 0.1.

The pH of the solution was adjusted to a range of _2.5 to 3.0 by adding an alkali agent of NaOH and Ca (OH) ₂ to the leached solution. The residue of the solid matter was filtered off from the pH-adjusted leachate solution to obtain a leach solution.

Next, the reducing light as described above was added to the above-mentioned leach solution to replace nickel in the solution and Fe in the reducing light to precipitate nickel, and the precipitate was separated to prepare a precipitation filtrate. The composition components of the precipitation filtrate and the contents of the respective components were measured, and the results are shown in Table 1.

Comparative Example  1 to 3

The precipitate filtrate prepared in the above Preparation Example was sprayed into a spray furnace maintained at 750 ° C using LNG gas and pyrolyzed to recover iron oxide using a dust collector, and the discharged chlorine gas was passed through water to recover hydrochloric acid.

Example  1 to 3

The precipitation filtrate prepared in the above Preparation Example was vacuum-evaporated (480 mbar, 79 ° C) and concentrated to obtain iron chloride crystals of FeCl ₂ .4H ₂ O.

The obtained iron chloride crystals were pyrolyzed at 500 ° C. to obtain iron oxide, and the discharged chlorine gas was passed through water to recover hydrochloric acid.

The concentration of Cl in the obtained iron oxide was measured, and the results are shown in Table 1. The higher the Cl concentration in the iron oxide, the lower the quality of the iron oxide.

Example  4

The precipitation filtrate prepared in the above Production Example was heated to evaporate water to concentrate the precipitation filtrate to produce iron chloride crystals of FeCl ₂ .2H ₂ O. The resulting iron chloride crystals were separated by filtration, and then dried with a hot air drier to obtain iron chloride crystals from which the adhesion water was removed.

As in Example 1, the obtained iron chloride crystals were pyrolyzed at 500 ° C to obtain iron oxide, and the discharged chlorine gas was passed through water to recover hydrochloric acid.

The concentration of Cl in the obtained iron oxide was measured, and the results are shown in Table 1.

Example  5

In Example 4, the iron chloride crystals obtained by evaporation and concentration were washed with a saturated aqueous solution of iron chloride to remove impurities.

The iron oxide was pyrolyzed in the same manner as in Example 4, and chlorine gas discharged was passed through water to recover hydrochloric acid.

The concentration of Cl in the obtained iron oxide was measured, and the results are shown in Table 1.

The precipitate filtrate composition (g / L) Impurity purification treatment Content of iron oxide
(weight%) Fe Mg K Ca Na Fe Cl Comparative Example 1 110 2.5 ≪ 0.1 7.5 ≪ 0.1 Absenteeism 55 3 Comparative Example 2 110 2.5 6.4 ≪ 0.1 ≪ 0.1 Absenteeism 54 4 Comparative Example 3 110 2.5 ≪ 0.1 ≪ 0.1 5.5 Absenteeism 53 4 Example 1 110 2.5 ≪ 0.1 7.5 ≪ 0.1 FeCl ₂ .4H ₂ O, crystallization 65 0.12 Example 2 110 2.5 6.4 ≪ 0.1 ≪ 0.1 FeCl ₂ .4H ₂ O, crystallization 65 0.08 Example 3 110 2.5 ≪ 0.1 ≪ 0.1 5.5 FeCl ₂ .4H ₂ O, crystallization 65 0.10 Example 4 110 2.5 ≪ 0.1 7.5 ≪ 0.1 FeCl ₂ .2H ₂ O, crystallization 65 0.11 Example 5 110 2.5 ≪ 0.1 7.5 ≪ 0.1 FeCl ₂ .2H ₂ O, crystallization
Hydrogen chloride water 66 <0.01

As can be seen from the above Table 1, it can be seen that the concentration of Cl contained in the iron oxide obtained in Example 1-4 is much smaller than that in Comparative Examples 1 to 3. [ Further, as can be seen from Example 5, when the iron chloride is washed with a saturated aqueous solution of iron chloride, the Cl content in the iron ore is less than 0.01 wt%, the chlorine content can be further reduced, and high quality iron oxide can be obtained.

Meanwhile, in the evaporation and concentration, the steam is supplied to the concentrator equipped with the heat exchanger, the moisture of the aqueous solution of the iron chloride is evaporated by heat exchange between the steam and the iron chloride solution, and the generated steam is supplied to the next step, The water of the aqueous solution of iron chloride was evaporated. This operation was carried out in four steps to evaporate water by evaporating the water of the aqueous solution of iron chloride. Further, the used and generated water vapor is supplied with energy by heating and mechanical compression to supply energy to the water vapor and reused in the evaporation concentration process.

As a result of reusing the steam generated in the process, it was confirmed that the energy consumption required for evaporating 1 kg of water was about 105 kcal. Considering that the amount of energy required to evaporate 1 kg of water is usually 540 kcal or more, the energy required for the evaporation and concentration process can be reduced to 1/5 by reusing steam.

Claims (15)

An aqueous solution containing chloride ions, alkali metal ions and iron ions discharged after recovering nickel in a nickel wet smelting process for recovering nickel using an acid solution containing chloride ions from nickel ore containing nickel and iron A method for recovering a by-product of a nickel wet smelting process for recovering a by-
A crystallization step of concentrating the aqueous solution by evaporation to crystallize the iron chloride; And
A roasting step of subjecting the crystallized iron chloride to solid-liquid separation, roasting, and pyrolysis with iron oxide and chlorine
By weight of the nickel-based smelting process.
The method according to claim 1, further comprising a water washing step of washing the crystallized iron chloride with an aqueous solution saturated with hydrochloric chloride to remove alkali ions.
The method according to claim 1, wherein the roasting step comprises roasting and crystallizing the crystallized iron chloride, followed by roasting and roasting.
4. The method according to any one of claims 1 to 3, wherein the alkali ion is at least one selected from the group consisting of Na, K and Ca.
The method according to any one of claims 1 to 3, wherein the crystallized iron chloride is obtained by heating an aqueous solution of iron chloride to evaporate and concentrate.
The method according to claim 5, wherein the crystallized iron chloride is obtained by evaporating and concentrating an aqueous solution of iron chloride under vacuum.
The method of claim 1 or 2, wherein the roasting is performed at a temperature of 400 ° C or higher.
4. The method of claim 3, wherein the roasting is performed at a temperature of 600-900 &lt; 0 &gt; C.
The method according to any one of claims 1 to 3, wherein the chlorine discharged from the roasting step is recovered as hydrochloric acid by water.
The method according to any one of claims 1 to 3, wherein the nickel chloride aqueous solution is evaporated using steam evaporated in the crystallization step.
The method according to claim 10, wherein the steam is heated or pressurized.
The process according to any one of claims 1 to 3, wherein the nickel wet smelting process
A leaching step of dissolving nickel ore containing Ni and Fe with hydrochloric acid to obtain an leached solution containing Ni and Fe ions;
Adjusting the pH by adding an alkaline agent to the obtained leach solution, and removing the solid impurities from the leach solution by solid-liquid separation;
A step of adding nickel ore containing Ni and Fe to the leach solution and then precipitating nickel into ferronickel to recover ferronickel;
A precipitate collecting step for collecting and recovering solid precipitate by solid-liquid separation from the precipitate
By weight of the nickel-based smelting process.
The method according to claim 12, wherein the leaching solution in the leaching step is formed by dissolving nickel ore containing nickel ore in hydrochloric acid and removing residual solid residue.
The method according to claim 12, wherein the alkaline agent is added so that the pH of the leach solution is 1.5 to 3.5.
15. The method of claim 14, wherein the alkaline agent is a mixture of metal hydroxides or metal hydroxides selected from the group consisting of Mg, Fe, Ni, Mn, Na, K and Ca.