JP4880909B2 - Purification method for removing sulfur from nickel compounds or cobalt compounds, and ferronickel production method - Google Patents

Description

  The present invention relates to a purification method for removing sulfur or chlorine from a nickel compound or a cobalt compound, and a method for producing ferronickel using the same.

  As a method for recovering nickel and cobalt from nickel or cobalt-containing oxide ore, as described in Patent Document 1, after removing impurities such as iron and aluminum from a solution obtained by leaching the oxide ore with sulfuric acid, There are a method of recovering nickel and cobalt as sulfides with an alkali sulfide compound, or a method of recovering nickel and cobalt as metal hydroxides or metal carbonates with an alkali compound as described in Patent Document 2.

JP-A-6-116660 JP 2000-234130 A

  Nickel, cobalt sulfides, hydroxides or carbonates are intermediate products containing impurities, and various processes are required to make nickel and cobalt final products.

  Nickel and cobalt sulfide contain about 50% by weight of nickel and cobalt together, and contain about 30% by weight of sulfur. Method, that is, after blowing oxygen or air under high temperature and high pressure with an autoclave device to dissolve as nickel sulfate and cobalt liquid, after separating nickel and cobalt and making them the final product of nickel and cobalt, after dissolving with hydrochloric acid The method of separating nickel and cobalt into the final product of nickel and cobalt is used.

  The final product by this method is obtained as metallic nickel, metallic cobalt, or a chemical product of nickel or cobalt.

  Nickel, cobalt hydroxide or carbonate contains about 40% by weight of nickel and cobalt and about 3 to 4% by weight of sulfur, and the sulfur content is about 1/10 compared to sulfide. However, it contains a large amount of impurities such as manganese and magnesium. Further, when leaching an oxide ore containing nickel and cobalt with sulfuric acid, when seawater or sodium salt, especially NaCl is used or added, 0.5 to 1 weight of chlorine is contained in nickel, cobalt hydroxide and carbonate. About% is contained.

  In order to produce nickel and cobalt as final products from this intermediate product, the following two methods are generally used, that is, after dissolving again with sulfuric acid, nickel and cobalt are separated, and the final product of nickel and cobalt is obtained. And a method of dissolving nickel and cobalt as a complex salt with ammonia and then separating nickel and cobalt to obtain a final product of nickel and cobalt.

  Both of the final products thus obtained are in the form of high purity metallic nickel, metallic cobalt or chemical products. However, in either case, it is necessary to invest in new equipment to obtain the final product from the intermediate product, resulting in an increase in cost. In addition, it is necessary to pay close attention to high purity, and skill in operation is required.

  In view of the above, as described in Patent Document 1, there is a method in which nickel, cobalt hydroxide, or carbonate, which is an intermediate product, is used as it is as a raw material for producing ferronickel. The feature in this case is that existing dry smelting equipment (for example, kiln and electric furnace) can be used as it is.

  A general method for producing ferronickel by dry smelting is to reduce nickel oxide ore together with auxiliary materials such as coal at a high temperature in a rotary kiln (calcination), and then smelting and reducing in an electric furnace to produce ferronickel. Is the method.

In such a dry smelting method, nickel, cobalt hydroxide or carbonate is reduced (calcined) at a high temperature in a rotary kiln when used as a raw material for ferronickel together with nickel oxide ore. Almost all sulfur and chlorine contained in the cobalt hydroxide and carbonate are removed as SO _x and chlorine gas in the exhaust gas.

  Therefore, in order to remove these elements in the exhaust gas due to environmental problems, it is necessary to install an exhaust gas removal device. In particular, when used together with nickel oxide ore, the amount of exhaust gas treated is enormous, and therefore there is room for improvement in that it requires a large amount of capital investment and costs for the treatment.

  Moreover, in order to produce ferronickel, about 20,000 KWH of electric power is required per ton of nickel. For example, in order to produce 40,000 tons of nickel annually, a huge amount of electric power of about 800 MWH is consumed. Is done. Therefore, if it is going to increase the production of ferronickel using the conventional nickel oxide ore, a new electric power of increased production x 20,000 KWH is required, which is not easy considering the recent energy problems and environmental problems. There was room for improvement.

  This invention is made | formed in view of the said situation, The place made into the objective is to refine | purify a nickel compound or a cobalt compound efficiently.

Another object of the present invention is to solve environmental problems and economic problems in ferronickel production by dry smelting using a metal hydroxide or metal carbonate containing nickel and cobalt.
Moreover, by using these for dry smelting, it is to increase the production of ferronickel without making new capital investment and without using new electric power. Furthermore, iron leaching is suppressed, the leaching rate of nickel and cobalt is improved, and the solution is effectively used.

According to the present invention, there is provided a purification method for removing sulfur or chlorine from a nickel compound or cobalt compound in which sulfur or chlorine is present inside the crystal,
After leaching nickel or cobalt from an oxide ore containing nickel or cobalt, obtaining the nickel compound or cobalt compound in which the sulfur or chlorine is present inside the crystal; and
A step of obtaining a slurry by mixing water, the obtained nickel compound or cobalt compound, and a sodium compound;
A stirring step of stirring the slurry;
Filtering the stirred slurry to obtain a solution containing sodium and a nickel or cobalt compound from which sulfur or chlorine has been removed; and
A nickel compound or cobalt compound from which sulfur or chlorine has been removed is used as a ferronickel dry refining raw material ,
The nickel compound or the cobalt compound, nickel hydroxide, nickel carbonate, purification and wherein the cobalt hydroxide or cobalt der Rukoto carbonate, are provided.

  According to the present invention, sulfur or chlorine contained in the nickel compound or cobalt compound can be removed by mixing and stirring the nickel compound or cobalt compound, sodium compound, and water. . Therefore, the sulfur content or the chlorine content of the nickel compound or cobalt compound can be reduced. Further, by mixing and stirring in the form of a slurry, not only the removal of sulfur or chlorine but also the nickel content or cobalt content of the nickel compound or cobalt compound can be increased.

  In the present invention, after the filtration step, using the solution containing sodium and sulfuric acid, leaching of nickel or cobalt from an oxide ore containing nickel, cobalt and iron to obtain a sulfuric acid leaching solution containing nickel or cobalt A process may be included.

  In the leaching process, iron or nickel contained in a sulfuric acid solution containing nickel or cobalt while effectively utilizing a solution containing sodium by leaching nickel or cobalt from oxide ore using a solution containing sodium and sulfuric acid Concentration can be controlled. Accordingly, an increase in cost in the nickel or cobalt manufacturing process can be suppressed. Furthermore, the leaching rate of nickel or cobalt in the oxide ore can be improved. As a result, it is possible to increase the recovery rate of nickel or cobalt from the oxidized ore while effectively using a solution containing sodium, and to suppress an increase in cost for recovering nickel or cobalt.

  In this invention, you may include the refinement | purification process which further refine | purifies the said nickel compound or the said cobalt compound from which the said sulfur or the said chlorine was removed after the said filtration process.

By using a nickel compound or cobalt compound from which sulfur or chlorine has been removed in advance in the purification step, it is possible to suppress an increase in the concentration of SO _x and Cl ₂ gas in the exhaust gas in the purification step. Therefore, the equipment cost for processing the exhaust gas can be reduced. Moreover, since the nickel content rate of a nickel compound or a cobalt compound is high compared with nickel oxide ore, the nickel content rate in a raw material can be raised. Therefore, the nickel content rate in ferronickel can be raised and the production amount of ferronickel can be increased. As a result, it is possible to increase the production of ferronickel while reducing the manufacturing cost.

According to the present invention,
A production method for producing ferronickel from iron and a nickel compound,
Carrying out the purification method according to the present invention using a nickel compound as a raw material, and obtaining the nickel compound by the filtration step;
A step of reducing the iron and the nickel compound by performing a heat treatment in a state where the nickel compound and iron coexist;
Obtaining ferronickel by melting the reduced iron and the nickel compound;
A method for producing ferronickel, comprising:
Is provided.

  According to the present invention, while reducing and melting in a state where the nickel compound obtained by the filtration step according to the present invention from which sulfur or chlorine has been removed and iron coexist, the manufacturing cost is reduced. , Ferronickel production can be increased.

According to the present invention, using a nickel compound or a cobalt compound in the manufacture of ferronickel by pyrometallurgical by SO _x and Cl ₂ in the exhaust gas generated during pyrometallurgical is reduced, the flue gas Operation without environmental problems is possible without newly installing a desulfurization device or the like. Moreover, ferronickel products can be increased in production using dry smelting equipment such as kilns and electric furnaces as they are.

  Furthermore, according to the present invention, by reusing a solution containing sodium element from a nickel, cobalt, or iron-containing oxide ore to a step of leaching nickel and cobalt with sulfuric acid, iron leaching is suppressed, and nickel, Cobalt leaching is promoted.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the amount used and the amount added are the amount used and the amount added based on the weight of each substance.

  The metal hydroxide containing nickel or cobalt used in the present embodiment is, for example, a sulfuric acid solution obtained by slurrying nickel or cobalt-containing oxide ore with seawater and leaching nickel or cobalt using sulfuric acid. From the above, iron and aluminum were neutralized and removed with limestone, and obtained as a metal hydroxide containing nickel and cobalt with an alkali compound such as magnesium oxide, magnesium hydroxide, or sodium hydroxide. Here, a metal carbonate containing nickel and cobalt can be obtained by using an alkali compound such as magnesium carbonate or sodium carbonate. Hereinafter, in this embodiment, the form using a metal hydroxide is demonstrated.

  Hereafter, the said process is demonstrated using FIGS. 1-3.

  FIG. 1 shows a process diagram for recovering nickel and cobalt from oxide ore.

  First, in step a (classification step (S1)), the oxidized ore 102 is classified into an oversize and an undersize. The undersize is made into slurry ore 104 with water 107, and the oversize is crushed into a pulverized product 103.

  Next, in step b (leaching step (S2)), the slurry ore 104 is leached with sulfuric acid 105 to obtain a sulfuric acid leaching solution 108 containing nickel and cobalt and a leaching residue 109. Here, the leaching residue 109 includes natrojarosite produced by the reaction of iron leached from the slurry ore 104, sulfuric acid 105, and the solution 208. The solution 208 is a reuse of the solution 208 generated in step h.

  Next, in step c (reaction step (S3)), the free sulfuric acid in the sulfuric acid leachate 108 containing the leaching residue 109 is reacted with magnesium contained in the pulverized product 103 pulverized in the classification step, thereby free sulfuric acid. Consume and adjust the pH to obtain a reaction solution 110 and a reaction residue 111. By this pH adjustment, natrojarosite is precipitated in the reaction residue 111, and the iron concentration in the reaction solution 110 is reduced.

  Subsequently, in step d (neutralization step (S4)), the neutralization agent 112 is added to the reaction residue 111 and the reaction solution 110 to adjust the pH, thereby obtaining the neutralization solution 113 and the neutralization residue 114. Here, in the reaction step of the previous step, natrojarosite is precipitated and the iron concentration in the reaction solution 110 is reduced, so the amount of the neutralizing agent 112 added can be reduced.

  Next, in step e (solid-liquid separation step (S5)), the flocculant 115 is added to the neutralization solution 113 including the neutralization residue 114, and solid-liquid separation is performed using a thickener. The neutralization residue 114 is separated.

  Next, in the process f (extraction process (S6)), the liquid from which iron and aluminum are removed from the neutralized liquid 113 and the organic solvent 134 containing the monothiophosphinic acid compound as an extractant are brought into contact. In step f, cobalt is selectively extracted by the organic solvent 134 to separate nickel and cobalt, thereby obtaining a nickel sulfate solution 130 and a cobalt sulfate solution 132.

  Next, in step g (solidification step (S7)), nickel hydroxide 138 and cobalt hydroxide 140 are obtained by mixing alkaline compound 136 with nickel sulfate solution 130 and cobalt sulfate solution 132, respectively. As the alkali compound, magnesium oxide, magnesium hydroxide, sodium hydroxide and the like can be used.

  Next, in the step h (sulfur / chlorine removal step (S8)), the water 205, the metal hydroxide 202 containing nickel or cobalt in a slurry state, and the sodium hydroxide 203 are mixed and stirred, and filtered. -By washing with water, a metal hydroxide 206 containing nickel or cobalt from which sulfur or chlorine has been removed and a solution 208 are obtained (FIG. 2).

  Next, in step i (ferronickel production step (S9)), metal hydroxide 206, oxide ore 218, and coal 210 are mixed and reduced (calcined) with a rotary kiln or the like. Next, the reduced mixture is charged into an electric furnace and melted to obtain ferronickel 212 (FIG. 3).

  Hereinafter, step h will be described in detail with reference to FIG.

  If the metal hydroxide 202 containing nickel or cobalt obtained in step g is sufficiently washed with river water or ground water after filtration, sulfate radicals and hydrochloric acid radicals attached to the surface are removed, but the washed metal The hydroxide 202 often contains about 2 to 5% sulfur and about 0.3 to 1% chlorine. The reason for this is presumed that sulfate radicals and chlorine radicals are taken in during the metal hydroxide crystal growth process and exist inside the crystal.

  In the present embodiment, the metal hydroxide 202 containing nickel or cobalt obtained in the step g is made into a slurry with the water 205, mixed with the sodium hydroxide 203 and stirred (mixing / stirring step (S81)). Here, in addition to sodium hydroxide 203, it may be mixed with sodium carbonate or a mixture of sodium hydroxide and sodium carbonate and stirred.

  By doing so, the sulfate radical and chlorine radical contained in the metal hydroxide 202 are removed, and the content of sulfur and chlorine contained in the metal hydroxide 202 can be reduced.

  In the mixing / stirring method, the metal hydroxide 202 may be slurried in advance with water 205, and sodium hydroxide, sodium carbonate or a mixture thereof may be added as a solid, or sodium hydroxide, sodium carbonate or a mixture thereof. The mixture may be liquid, and the metal hydroxide 202 containing nickel or cobalt may be added as a solid to form a slurry. Moreover, you may add what was made into the slurry form and what was made into the liquid form.

  The slurry concentration may be a concentration that allows mixing and stirring, but is more preferably about 10 to 50% from the viewpoint of operational stability.

  The amount of sodium hydroxide 203 used is desirably 0.05 times to 1 times the weight, and 0.1 times to 0.5 times the weight of the dry weight of the metal hydroxide 202. More desirable. That is, the amount of sodium hydroxide 203 used is preferably 5% by weight or more and 100% by weight or less of the dry weight of the metal hydroxide 202, and more preferably 10% by weight or more and 50% by weight or less.

  The removal effect of sulfur and chlorine contained in the metal hydroxide 202 can be improved by setting the weight preferably 0.05 times or more, more preferably 0.1 times or more.

  In addition, the production cost is preferably 1 times the weight or less, more preferably 0.5 times the weight or less, without greatly increasing the amount of sodium hydroxide 203 used while maintaining the effect of removing sulfur and chlorine. Can be suppressed.

  The mixing / stirring temperature is preferably 20 ° C to 100 ° C, more preferably 50 ° C to 100 ° C.

  By mixing and stirring at a temperature of 20 ° C. or higher, preferably 50 ° C. or higher, the amount of sodium hydroxide 203 used can be reduced, and for example, metal hydroxide can be obtained by mixing and stirring for a short time such as about 30 minutes. Removal of sulfur and chlorine from the product 202 can be performed efficiently.

  By mixing and stirring at a temperature of 100 ° C. or lower, sulfur and chlorine can be removed without using a pressure vessel, and an increase in cost required for the equipment can be suppressed. Moreover, operation can be performed stably.

  After the slurry 204 thus obtained is filtered by a filter press or the like, the metal hydroxide 206 and sodium containing nickel or cobalt are washed by washing with water containing no sulfate or hydrochloric acid radicals such as river water. It is possible to obtain a solution 208 containing the solution (filtration and water washing step (S82)).

  It is more desirable that the amount of water used for washing be more than twice the dry weight of the metal hydroxide 202 containing nickel or cobalt. This is because it becomes easier to remove sulfur and chlorine contained in the metal hydroxide 202.

Here, by the slurrying with the sodium hydroxide solution, the crystallinity of nickel hydroxide is improved and recrystallization proceeds. Also, _{Ni (OH) 2 · 0.75H 2} O → Ni (OH) varies in _two crystal structure. This change in crystal structure leads to an increase in the nickel content of nickel hydroxide, and the nickel content of nickel hydroxide without the same weight of hydrate is equal to the nickel content of nickel hydroxide with hydrate. Increase in comparison.

  By mixing water 205, sodium hydroxide 203, and metal hydroxide 202, mixing and stirring as a slurry can not only remove sulfur and chlorine but also improve the nickel content of metal hydroxide 206. It becomes. In addition, the cobalt content of the metal hydroxide 206 can be improved.

  Next, a method for leaching nickel and cobalt from the oxide ore 102 (FIG. 1) using the solution 208 containing sodium will be described.

  The solution 208 washed with filtered water contains sodium, and its concentration depends on the amount of sodium salt used and the slurry concentration, but contains sodium element, for example, about 4 to 100 g / l. Is 7 or more. In the present embodiment, the solution 208 is reused in the step b (leaching step), and nickel and cobalt are leached from the oxidized ore 102 using the oxidized ore 102, the sulfuric acid 105, and the solution 208. For reasons described later, the leaching rate of iron from the oxide ore 102 in the leaching step is controlled, and it becomes possible to reduce the iron concentration in the sulfuric acid leaching solution 108 and improve the leaching rate of nickel and cobalt.

  The solution 208 after washing with filtered water may be neutralized to about pH 7 with sulfuric acid or hydrochloric acid and discarded.

  The reason why the concentration of iron in the sulfuric acid leachate 108 is controlled by sodium is considered to be due to the following chemical reaction formulas (1) and (2).

FeO (OH) · (oxide ore) + 3 / 2H ₂ SO ₄ = 1 / 2Fe ₂ (SO ₄ ) ₃ · (liquid) + 2H ₂ O (1)

Fe ₂ (SO ₄ ) ₃ · (Liquid) + 1 / 3Na ₂ SO ₄ + 4H ₂ O = 2 / 3NaFe ₃ (SO ₄ ) ₂ (OH) ₆ · (solid) + 2H ₂ SO ₄ (2)

  The reason why the leaching rate of nickel and cobalt is improved is considered to be that free sulfuric acid generated by the above reaction formula (2) reacts with nickel and cobalt in the oxide ore. Hereinafter, this reaction formula is shown.

NiO (oxide ore) + H ₂ SO ₄ = NiSO ₄ + H ₂ O (3)

CoO (oxide ore) + H ₂ SO ₄ = CoSO ₄ + H ₂ O (4)

  By reusing the solution 208 containing sodium element, which is a filtered water washing solution, in step b, the concentration of iron contained in the sulfuric acid leachate 108 containing nickel and cobalt is controlled while effectively using the filtered water washing solution. Therefore, it is possible to suppress an increase in cost for precipitating and removing iron in the subsequent step d. Furthermore, the leaching rate of nickel and cobalt in the oxide ore 102 can be improved. As a result, it is possible to increase the recovery rate of nickel and cobalt from the oxidized ore 102 while effectively utilizing the filtered water washing solution, and to suppress an increase in cost for recovering nickel and cobalt.

  Next, a method (step i) for producing ferronickel will be described. In this step, a metal hydroxide 202 containing nickel and cobalt, sodium hydroxide 203, and water for use 205 are mixed to form a slurry. This is a process for producing ferronickel by using a metal hydroxide 206 containing nickel and cobalt containing sulfur and chlorine, obtained by washing with filtered water after stirring the slurry, as a raw material for ferronickel dry smelting. .

  In FIG. 3, the manufacturing process of the ferronickel by the dry smelting method in this embodiment is shown.

  In this embodiment, the oxide ore 218 containing iron and nickel and the metal hydroxide 206 are used as the main raw material, and the coal 210 is used as the auxiliary raw material. In addition, ferronickel is produced by a dry smelting method by reducing almost the entire amount of nickel and a part of iron using a kiln and an electric furnace. Here, equipment other than the kiln, for example, a method using a vertical shaft furnace, or a blast furnace used when iron is produced from iron ore instead of an electric furnace may be used.

  In the present embodiment, the oxidized ore 218 contains about 25% by weight to 30% by weight of attached moisture. After drying and reducing the adhering moisture content to about 20% by weight, the coal 210 is charged together with the coal 210.

  The amount of coal 210 used is determined by taking into account the combustion loss rate based on the total amount of nickel and the amount by which a portion of iron is reduced.

  Here, the metal hydroxide 206 contains about 40 to 50% by weight of adhering water. In this embodiment, the metal hydroxide 206 is mixed with the oxide ore 218 and charged into the kiln (mixing step), and reduced ( Baked).

  The amount of coal 210 used is an amount that takes into account the combustion loss based on the amount of oxide ore 218 containing iron and nickel, the amount of all the nickel contained in metal hydroxide 206 being reduced, and the like.

  In this embodiment, a rotary kiln in which the inside of the cylindrical shell is protected with bricks is used as the kiln, but other types of kilns may be used.

  In the present embodiment, the rotary kiln is slightly inclined, and the raw material moves in the rotary kiln with the rotation of about 1 to 10 rpm. Moreover, the inside of a rotary kiln becomes high temperature by combustion of pulverized coal etc. by the burner attached to the discharge port side. The hot gas generated by the high temperature inside the rotary kiln flows toward the raw material charging side by an induction blower installed outside the raw material inlet side system. Preheating and reduction (calcination) to produce reduced ore (reduction step (S91)).

  Here, the maximum temperature in the rotary kiln is preferably controlled in the range of 600 ° C. to 1200 ° C., more preferably in the range of 800 ° C. to 1100 ° C., by combustion of pulverized coal or the like. In this embodiment, the maximum temperature is controlled to be about 1000 ° C.

  By making the maximum temperature in the rotary kiln preferably 600 ° C. or higher, more preferably 800 ° C. or higher, the decomposition rate of crystal water in the metal hydroxide 206 is improved, and the amount remaining in the raw material is increased. Can be suppressed. Therefore, when the metal hydroxide 206 is charged into the electric furnace used in the next step, it is possible to suppress vaporization of crystal water due to a sudden rise in the raw material temperature in the electric furnace. Therefore, the operation of the electric furnace can be performed stably.

  By setting the maximum temperature in the rotary kiln to preferably 1200 ° C. or less, more preferably 1100 ° C. or less, the oxide generated by the decomposition of the crystal water while maintaining the decomposition rate of the crystal water in the metal hydroxide 206 Growth due to fusion bonding with nickel oxide ore can be suppressed. Therefore, it is possible to suppress the fusion bond from adhering to the inner surface of the rotary kiln and being discharged to the outside of the rotary kiln while growing in a lump, and the rotary kiln and the electric furnace in the next process can be stably operated.

Sulfur and chlorine contained in the metal hydroxide 206 are almost entirely decomposed in the rotary kiln when the maximum temperature in the kiln is in the range of 600 ° C. to 1200 ° C., and as SO _x gas and Cl ₂ gas in the exhaust gas 216. Released. Therefore, it is possible to operate without increasing the concentration of SO _x and Cl ₂ gas in the exhaust gas 216 by using the metal hydroxide 206 containing nickel from which sulfur and chlorine have been removed in advance by the above-described method. it can. Therefore, it is not necessary to newly install an exhaust gas treatment facility, and the cost for investing in the facility can be reduced.

  Next, the reduced ore is melted by charging it into an electric furnace, and almost all the nickel contained in the reduced ore and a part of iron are reduced. By doing so, the purified ferronickel 212 can be taken out from the electric furnace. Further, slag 214 and exhaust gas 216 are discharged from the electric furnace (refining step (S92)). Here, in this embodiment, the temperature in the electric furnace is about 1600 ° C.

  Ferronickel 212 taken out from the electric furnace is used as a raw material for stainless steel. Moreover, since slag contains many magnesium, it can also be used as a neutralizing agent in the process d.

  In addition, since the nickel content of the metal hydroxide 206 is 40% or more, the metal hydroxide 206 and the oxide ore 218 containing iron and nickel are mixed and used. The average nickel content can be increased. Here, when ferronickel is produced with the same amount of mixed raw material used as in the case of nickel oxide ore, the nickel content in ferronickel also increases substantially corresponding to the ratio of the nickel content in the raw material. Therefore, it becomes possible to increase the production amount of ferronickel. Therefore, it is possible to increase the production of ferronickel without installing a new dry-type facility or improving the facility, or without newly using electric power.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.

  For example, in the above-described embodiment, the form of removing sulfur from the metal hydroxide 202 containing nickel or cobalt and the form of manufacturing the ferronickel 212 using the metal hydroxide 206 containing nickel or cobalt have been described. The present invention can be applied to various metal compounds without being limited thereto. For example, even if nickel hydroxide, nickel carbonate, metal hydroxide containing nickel and cobalt, metal carbonate containing nickel and cobalt, and a mixture thereof, the same effect as described in the above embodiment is obtained. Obtainable.

  Moreover, in the said embodiment, although the form which mixes and stirs the metal hydroxide 202 using sodium hydroxide was demonstrated, this invention is applicable not only to this but various sodium compounds. For example, even when sodium carbonate or a mixture of sodium hydroxide and sodium carbonate is used, the same effect as that described in the above embodiment can be obtained.

  Moreover, in the said embodiment, although the form which makes the temperature in an electric furnace about 1600 degreeC was demonstrated, it should just be the range of 1400 degreeC-1700 degreeC which is the temperature which can manufacture ferronickel.

In the above embodiment has been described embodiment using coal as auxiliary raw material for the reduction of nickel and iron in a rotary kiln, for example, coke, H ₂ gas, such as CO gas, others Even so long as it can reduce nickel and iron in the rotary kiln.

  Moreover, in the said embodiment, what mixed the metal hydroxide 206 containing nickel or cobalt, and the oxide ore 218 containing iron and nickel is reduced with a rotary kiln, and it inserts into an electric furnace and fuse | melts it. As described above, the metal hydroxide 206 and coal may be reduced in a rotary kiln without mixing the oxide ore 218, and then charged in an electric furnace and melted.

  Moreover, in the said embodiment, although the metal hydroxide 206 and the oxide ore 218 were mixed and the form reduced with a rotary kiln with coal as an auxiliary material was demonstrated, the metal hydroxide 206 is baked using a rotary kiln. In some cases (firing step), an oxide containing nickel or cobalt may be obtained, and the oxide, oxide ore 218 and coal may be mixed and reduced in a rotary kiln. Here, in the firing step, the desirable range of the maximum temperature in the rotary kiln is 600 ° C. or more and 1200 ° C. or less. By performing the firing step in this temperature range, the operation of the electric furnace and the rotary kiln is more stable as in the reduction step. Can be done automatically. Moreover, since the metal hydroxide 206 is excellent in handling property compared with the oxidized ore 218, the metal hydroxide 206 may be reduced together with coal in a rotary kiln in a separate system from the oxidized ore 218. Further, the metal hydroxide 206 may be reduced together with the oxide ore 218 in advance in the rotary kiln after the attached moisture is reduced in advance.

  Moreover, in the said embodiment, although the form which removes sulfur and chlorine from the metal hydroxide 202 containing nickel or cobalt was demonstrated, only sulfur may be removed or even if only chlorine is removed. Good.

  Moreover, in the said embodiment, although the form which improves the content rate of nickel was demonstrated in the process i, this invention is applicable not only to this but cobalt.

  Hereinafter, the present invention will be specifically described by way of examples.

(Experimental example 1)
The metal hydroxide of sample No. 1 shown in Table 1 uses sulfuric acid to leach nickel and cobalt from an oxidized ore containing nickel, cobalt, and iron to obtain a sulfuric acid solution containing nickel and cobalt, and neutralizes it. Nickel and cobalt are recovered in the form of metal hydroxide by magnesium oxide from a neutralized solution obtained by neutralizing and removing iron and aluminum using an agent.

  The metal carbonate of sample No. 2 shown in Table 1 uses sulfuric acid to leach nickel and cobalt from an oxidized ore containing nickel, cobalt and iron to obtain a sulfuric acid solution containing nickel and cobalt, and a neutralizing agent. Is obtained by recovering nickel and cobalt in the form of metal hydroxide with sodium carbonate from a neutralized solution obtained by neutralizing and removing iron and aluminum.

  In addition, both sample No1 and sample No2 can leach nickel and cobalt from an oxide ore containing nickel, cobalt, and iron to obtain a sulfuric acid solution containing nickel and cobalt. Seawater was used as water for slurrying oxide ore.

  When the metal hydroxide and metal carbonate obtained in this manner are filtered with a filter press and then thoroughly washed with river water, the metal hydroxide and metal carbonate are washed despite being sufficiently washed with river water. It was found that a considerable amount of sulfur and chlorine remained in the chemical and could not be removed by washing with river water alone.

  In FIG. 4, the X-ray-diffraction result of sample No1 is shown.

As can be seen from the diffraction peak shown in FIG. 4, the measurement peak is unclear. Therefore, sample No1 was nickel hydroxide having a crystal structure of Ni (OH) ₂ .0.75H ₂ O, but the crystallinity was weak and was found to be close to amorphous. It was also found that nickel hydroxide exists in the form of a hydrate. For this reason, it is presumed that sulfate radicals and chlorine radicals are taken in during the crystal growth process of metal hydroxide or metal carbonate, and sulfate radicals and chlorine radicals are present inside the crystal.

(Experimental example 2)
FIG. 5 is a diagram showing an X-ray diffraction result when the metal hydroxide of sample No. 1 and 95 ° C. warm water are mixed, stirred as a slurry, and filtered. The diffraction peak in FIG. 5 was almost the same as the diffraction peak in FIG. 4, and it was found that the crystal was weak in crystallinity and was a nickel hydroxide hydrate close to amorphous.

  FIG. 6 is a diagram showing an X-ray diffraction result when the metal hydroxide of the same sample No. 1 and a sodium hydroxide solution are mixed, stirred in a slurry state at a temperature of 95 ° C. for 30 minutes, filtered, and washed with water. is there. As can be seen from the diffraction peak in FIG. 6, the measurement peak is clear. Therefore, it was found that the nickel hydroxide of sample No. 1 was recrystallized. It was also found that it exists in the form of nickel hydroxide which is not a hydrate.

  As shown in FIG. 5, no change was observed in the crystallinity of nickel hydroxide in hot water, but as shown in FIG. 6, the crystallinity of nickel hydroxide was improved by slurrying with a sodium hydroxide solution. As a result, it was found that recrystallization was progressing. Therefore, it turned out that the content rate of nickel in nickel hydroxide rises.

(Examples and Comparative Examples)
Table 2 shows the conditions in which nickel hydroxide and nickel carbonate containing nickel and cobalt were stirred and treated as a slurry with sodium hydroxide and sodium carbonate. Table 3 shows the results of removing sulfur and chlorine.

  Hereinafter, the process of removing sulfur and chlorine and the experimental results will be described using Examples 1 to 6 and Comparative Examples 1 and 2.

Example 1
A metal hydroxide containing nickel and cobalt of sample No. 1 shown in Table 1 was used, and the slurry concentration was adjusted to 20% with river water.

  To this slurry, 0.2 times weight of NaOH was added to the dry weight of the metal hydroxide, and the mixture was stirred at 95 ° C. for 30 minutes. Then, it filtered with the vacuum filter, and also washed with water with the river water 4 times weight with respect to the dry weight of a metal hydroxide. When the metal hydroxide filtered and washed with water was dried and analyzed, Ni: 47.23%, Co: 1.55%, S: 0.01%, Cl: 0.08%, sulfur from the metal hydroxide It was also found that the chlorine removal effect was great. Further, the nickel content of the metal hydroxide after the process of removing sulfur and chlorine was increased about 1.17 times compared to the nickel content of the metal hydroxide of sample No1. Further, the cobalt content increased about 1.15 times.

(Example 2)
The test was performed under the same conditions as in Example 1 except that the test was performed at a temperature of 80 ° C.

  The metal hydroxide filtered and washed with water was dried and analyzed. Ni: 48.45%, Co: 1.56%, S: 0.10%, Cl: 0.14%. Compared with the nickel content of No1, it increased about 1.21 times. Further, the cobalt content increased about 1.16 times.

(Example 3)
The test was carried out under the same conditions as in Example 1 except that NaOH was added in a weight 0.1 times the dry weight of the metal hydroxide.

  The metal hydroxide filtered and washed with water was dried and analyzed. Ni: 46.44%, Co: 1.58%, S: 0.97%, Cl: 0.25%. Compared with the nickel content of No1, it increased about 1.16 times. Further, the cobalt content increased about 1.17 times.

Example 4
This was carried out under the same conditions as in Example 1 except that Na ₂ Co ₃ was used instead of NaOH and 0.4 times the weight of the metal hydroxide was added.

  When the metal hydroxide filtered and washed with water was dried and analyzed, it was Ni: 46.63%, Co: 1.55%, S: 0.64%, Cl: 0.14%. Compared with the nickel content of No1, it increased about 1.16 times. Further, the cobalt content increased about 1.15 times.

(Comparative Example 1)
To the metal hydroxide of sample No. 1, NaOH or Na ₂ CO ₃ was not added, and it was stirred at 95 ° C. for 30 minutes at a slurry concentration of 20% with river water and washed with filtered water.

  When the metal hydroxide washed with filtered water was dried and analyzed, Ni: 40.32%, Co: 1.37%, S: 3.40%, Cl: 0.62%, nickel of metal hydroxide The content and cobalt content were hardly changed, and the effect of removing sulfur and chlorine from the metal hydroxide was small.

(Example 5)
A metal carbonate containing nickel and cobalt of sample No. 2 shown in Table 1 was used, and the slurry concentration was adjusted to 20% with river water.

  To this slurry, 0.2 times weight of NaOH was added to the dry weight of the metal hydroxide, and the mixture was stirred at 95 ° C. for 30 minutes. Then, it filtered with the vacuum filter, and also washed with water with the river water 4 times weight with respect to the dry weight of a metal hydroxide. When the metal carbonate filtered with water was dried and analyzed, Ni: 54.33%, Co: 1.95%, S: 0.05%, Cl: 0.02%, and the effect of removing sulfur and chlorine was great. I understood it. Further, the nickel content of the metal carbonate after the process of removing sulfur and chlorine was increased about 1.12 times compared to the nickel content of sample No2. Further, the cobalt content increased about 1.1 times.

(Example 6)
Except for using _Na 2 CO ₃ instead of NaOH was performed under the same conditions as in Example 5.

  When the metal carbonate filtered and washed with water was dried and analyzed, Ni: 53.86%, Co: 1.91%, S: 0.53%, Cl: 0.04%, and the nickel content was Sample No. 2. As compared with the nickel content of the steel, it increased about 1.11 times. Further, the cobalt content increased to about 1.09 times.

(Comparative Example 2)
To the metal carbonate of sample No. 2, NaOH or Na ₂ CO ₃ was not added, and the mixture was stirred with river water at a slurry concentration of 20% at 95 ° C. for 30 minutes and washed with filtered water.

  When the metal carbonate filtered with water was dried and analyzed, Ni: 48.80%, Co: 1.78%, S: 3.76%, Cl: 0.5%, and nickel contained in the metal carbonate And the cobalt content were hardly changed, and the effect of removing sulfur and chlorine from the metal carbonate was small.

  In Examples 1 to 6, a metal hydroxide or metal carbonate having a large effect of removing sulfur and chlorine from the metal hydroxide or metal carbonate and having a small content of sulfur and chlorine was obtained. Moreover, the metal hydroxide or metal carbonate with which nickel content rate and cobalt content rate rose was obtained.

  Table 4 shows nickel hydroxide and nickel carbonate containing nickel and cobalt, and the filtered water washing solution containing sodium after stirring and treating with sodium hydroxide and sodium carbonate as a slurry, containing nickel, cobalt, iron, and magnesium. The results of leaching of nickel, cobalt, iron and magnesium when reused in the process of leaching with oxide ore and sulfuric acid are shown.

  Next, processes and experimental results when a filtered aqueous solution containing sodium element is used for leaching oxide ore will be described using Example 7, Example 8, and Comparative Example 3.

(Example 7)
The filtered water washing solution containing 15 g / l of sodium element obtained in Example 1 was adjusted to pH: 7 with a small amount of sulfuric acid.

  This filtered washing solution and under or 2mm ore of nickel or cobalt, iron or magnesium-containing oxide ore, classified by 2mm sieve, are made into 23% by weight slurry ore and 98% by weight sulfuric acid before classification The total oxide ore was added 0.73 times the weight, and leached by stirring at 95 ° C. and atmospheric pressure for 6 hours. To the sulfuric acid leachate and leaching residue obtained in this way, the filtered ore washing solution containing 12 g / l of sodium element was added to the pulverized product of over 2 mm oxide ore to add 40% by weight slurry ore. The mixture was reacted with stirring at 95 ° C. and atmospheric pressure for 6 hours. When the leaching rate after the normal pressure reaction was examined, Ni was 89%, Co: 75.3%, Fe: 6.5%, Mg: 82.6%. Control of iron leaching rate was achieved.

(Example 8)
The filtered water washing solution containing 23 g / l of sodium element obtained in Example 4 was adjusted to pH: 7 with a small amount of sulfuric acid. This filtered washing solution and under 2mm ore classified with a 2mm sieve among the oxidized ores containing nickel, cobalt, iron and magnesium are made into 23% concentration slurry ore and 98% by weight sulfuric acid before classification 0.73 times the weight of the total oxide ore was added, and the mixture was stirred and leached at 95 ° C. and atmospheric pressure for 6 hours. To the sulfuric acid leachate and leaching residue obtained in this way, the filtered ore washing solution containing 23 g / l of sodium element was added to the crushed product of over 2 mm oxide ore to add the oxide ore to a slurry ore with a concentration of 40% by weight. The mixture was reacted with stirring at 95 ° C. and atmospheric pressure for 6 hours.

  When the leaching rate after the normal pressure reaction was examined, Ni was 90.3%, Co: 78.5%, Fe: 4.3%, Mg: 85.3%, and the leaching rate of nickel and cobalt was improved. At the same time, control of the iron leaching rate was achieved.

(Comparative Example 3)
Underwater 2 mm ore classified with river water and nickel or cobalt, iron or magnesium containing 2 mm sieve, and made 23% by weight slurry ore and 98% by weight sulfuric acid before classification 0.73 times the weight of the oxide ore was added, and the mixture was stirred and leached for 6 hours at a temperature of 95 ° C. and atmospheric pressure.

  To the sulfuric acid leachate and leaching residue obtained in this way, the river ore is added to the crushed product of over 2 mm oxide ore to add 40% strength slurry ore, and the temperature is 95 ° C. and atmospheric pressure. The reaction was stirred for 6 hours.

  When the leaching rate after the normal pressure reaction was examined, Ni: 81.3%, Co: 60.5%, Fe: 32.7%, Mg: 82.5%, and the leaching rates of nickel and cobalt were The iron leaching rate increased.

  In Example 7 and Example 8, the nickel and cobalt leaching rate was improved and the iron leaching rate was controlled, and a nickel sulfate solution and a cobalt sulfate solution with low iron content were obtained.

  Next, an experimental process for producing ferronickel using nickel hydroxide subjected to a treatment for removing sulfur or chlorine and nickel oxide ore containing iron and results thereof, Example 9, Comparative Example 4 and Comparative Example 5 will be described. Table 5 shows the components of ferronickel and the amount of nickel, and Table 6 shows the distribution ratio of sulfur to ferronickel, slag, and exhaust gas.

(Comparative Example 4)
In Comparative Example 4, ferronickel was produced without mixing nickel hydroxide.

  A dry weight of 100 kg of nickel oxide ore containing Ni: 2.4%, Fe: 12.3%, S: 0.025% and a dry weight of 7 kg of coal containing S: 0.4% are mixed. Then, the temperature was raised from room temperature to 1000 ° C. in a nitrogen gas atmosphere in 1 hour, and held at 1000 ° C. for 20 minutes to reduce (calcinate) the nickel oxide ore. Then, it cooled to normal temperature with nitrogen gas atmosphere. This reduced ore (calcite ore) was melted at a temperature of 1600 ° C. using an electric furnace rated at 50 KVA, and reduced and smelted in total with a total power consumption of 90 KWH to produce ferronickel metal and slag. At this time, the components of ferronickel metal were Ni: 20.2% and S: 0.18%, and 11.72 kg of metal was obtained. Therefore, the nickel content was 2.37 kg. The amount of slag produced was 78.1 kg, and the sulfur component in the slag was 0.019%. Therefore, the distribution amount (ratio) of S was ferronickel metal: 0.021 kg (40%), slag: 0.015 kg (28%), and exhaust gas: 0.017 kg (32%).

(Comparative Example 5)
In Comparative Example 5, ferronickel was produced using a raw material obtained by mixing nickel hydroxide not subjected to the treatment for removing sulfur or chlorine and nickel oxide ore containing iron.

  97.5 kg of dry weight of nickel oxide ore containing Ni: 2.4%, Fe: 12.3%, S: 0.025%, and dry weight of metal hydroxide having the components of sample No. 1 in Table 1 2.5 kg and a dry weight of 7.5 kg of coal containing S: 0.4% are mixed, heated from room temperature to 1000 ° C. in a nitrogen gas atmosphere in 1 hour, and held at 1000 ° C. for 20 minutes, Nickel oxide ore and metal hydroxide were reduced (calcined). Then, it cooled to normal temperature with nitrogen gas atmosphere. This reduced ore (calcite ore) was melted at a temperature of 1600 ° C. using an electric furnace rated at 50 KVA, and reduced and smelted in total with a total power consumption of 90 KWH to produce ferronickel metal and slag.

  At this time, the components of ferronickel metal were Ni: 26.3% and S: 0.17%, and 12.51 kg of metal was obtained. Therefore, the nickel content was 3.29 kg. The amount of slag produced was 76.2 kg, and the S component in the slag was 0.02%. By using metal hydroxide with nickel oxide ore at a usage rate of only 2.5%, the production of pure nickel with the same total power consumption increased 1.39 times. However, the distribution amount (ratio) of S is ferronickel: 0.021 kg (15%), slag: 0.015 kg (10%), exhaust gas: 0.108 kg (75%), and the weight of S in the exhaust gas is It was 6.35 times higher than that of Comparative Example 4.

Example 9
In Example 9, ferronickel was manufactured using the raw material which mixed the nickel hydroxide by which the process which removes sulfur and chlorine was given, and the nickel oxide ore containing iron.

  97.5 kg of dry weight of nickel oxide ore containing Ni: 2.4%, Fe: 12.3%, S: 0.025%, and dry of metal hydroxide having the components of Table 3 and Example 1 Mix 2.5 kg of weight and 7.5 kg of dry weight of coal containing S: 0.4%, raise the temperature from room temperature to 1000 ° C. in 1 hour in nitrogen gas atmosphere, and hold at 1000 ° C. for 20 minutes. Then, nickel oxide ore and metal hydroxide were reduced (calcined). Then, it cooled to normal temperature with nitrogen gas atmosphere.

  This reduced ore (calcined ore) was melted at a temperature of 1600 ° C. using an electric furnace rated at 50 KVA, and reduced and smelted with a total power consumption of 90 KWH to produce ferronickel and slag.

  At this time, the components of ferronickel were Ni: 27.33% and S: 0.16%, and 12.69 kg of metal was obtained. Therefore, the nickel content was 3.47 kg. The amount of slag produced was 74.6 kg, and the S component in the slag was 0.021%.

  By using metal hydroxide with nickel oxide ore at a usage rate of only 2.5%, the production of pure nickel with the same total power consumption increased by 1.46 times.

  Moreover, the distribution amount (ratio) of sulfur is ferronickel: 0.02 kg (36%), slag: 0.016 kg (29%), exhaust gas: 0.019 kg (35%), and sulfur in the exhaust gas is a comparative example. 4 and almost the same as that of Comparative Example 5, which was 0.18 times lower.

  In Example 9, ferronickel having a high nickel content was obtained. Moreover, the sulfur content in the exhaust gas could be reduced.

It is a flowchart for demonstrating the manufacturing process which concerns on embodiment. It is a flowchart for demonstrating the manufacturing process which concerns on embodiment. It is a flowchart for demonstrating the manufacturing process which concerns on embodiment. It is a figure for demonstrating the X-ray-diffraction result of the sample which concerns on an experiment example. It is a figure for demonstrating the X-ray-diffraction result of the sample which concerns on an experiment example. It is a figure for demonstrating the X-ray-diffraction result of the sample which concerns on an experiment example.

Explanation of symbols

102 Oxide ore 103 Ground product 104 Slurry ore 105 Sulfuric acid 107 Water 108 Sulfuric acid leaching solution 109 Leaching residue 110 Reaction solution 111 Reaction residue 112 Neutralizing agent 113 Neutralizing solution 114 Neutralization residue 115 Flocculant 202 Metal hydroxide 203 Sodium hydroxide 204 Slurry 205 Water 206 Metal hydroxide 208 Solution 210 Coal 212 Ferronickel 214 Slag 216 Exhaust gas 218 Oxide ore

Claims (17)

A purification method for removing sulfur or chlorine from a nickel compound or cobalt compound in which sulfur or chlorine is present inside the crystal,
After leaching nickel or cobalt from an oxide ore containing nickel or cobalt, obtaining the nickel compound or cobalt compound in which the sulfur or chlorine is present inside the crystal; and
A step of obtaining a slurry by mixing water, the obtained nickel compound or cobalt compound, and a sodium compound;
A stirring step of stirring the slurry;
Filtering the stirred slurry to obtain a solution containing sodium and a nickel or cobalt compound from which sulfur or chlorine has been removed; and
A nickel compound or cobalt compound from which sulfur or chlorine has been removed is used as a ferronickel dry refining raw material ,
The nickel compound or the cobalt compound, nickel hydroxide, nickel carbonate, purification and wherein the cobalt hydroxide or cobalt der Rukoto carbonate. The purification method according to claim 1 ,
The said sodium compound contains sodium hydroxide or sodium carbonate, The purification method characterized by the above-mentioned. The purification method according to claim 1 or 2 ,
The weight of the said sodium compound is 5 to 100 weight% of the weight of the said nickel compound or the said cobalt compound, The purification method characterized by the above-mentioned. The purification method according to any one of claims 1 to 3 ,
The said stirring process is performed at the temperature of 50 to 100 degreeC, The purification method characterized by the above-mentioned. The purification method according to any one of claims 1 to 4 ,
After the filtration step, a leaching step of leaching nickel or cobalt from an oxide ore containing nickel, cobalt, and iron using the solution containing sodium and sulfuric acid to obtain a sulfuric acid leaching solution containing nickel or cobalt is included. A purification method. The purification method according to any one of claims 1 to 4 ,
A purification method comprising a purification step of further purification by heating and melting the nickel compound or cobalt compound from which the sulfur or chlorine has been removed after the filtration step. The purification method according to claim 6 , wherein
A purification method comprising a mixing step of mixing the nickel compound from which the sulfur or chlorine has been removed and ore containing nickel between the filtration step and the purification step to obtain a mixture. The purification method according to claim 6 , wherein
A purification method comprising a mixing step of mixing the cobalt compound from which sulfur or the chlorine has been removed and an ore containing cobalt between the filtration step and the purification step. The purification method according to claim 7 or 8 ,
A purification method comprising a reduction step of reducing the mixture between the mixing step and the purification step. The purification method according to claim 7 ,
A purification method comprising a reduction step of reducing the nickel compound and reducing the ore containing nickel before the mixing step. The purification method according to claim 8 , wherein
A purification method comprising a reduction step of reducing the cobalt compound and reducing the ore containing cobalt before the mixing step. The purification method according to claim 7 or 8 ,
Before the mixing step, including a firing step of firing the nickel compound or the cobalt compound at a temperature of 600 ° C. or higher and 1200 ° C. or lower to obtain an oxide containing nickel or cobalt,
A purification method comprising a reduction step of reducing the mixture between the mixing step and the purification step. The purification method according to any one of claims 9 to 12 ,
A purification method, wherein the reduction step is performed at a temperature of 600 ° C. or higher and 1200 ° C. or lower. The purification method according to any one of claims 9 to 13 ,
The said reduction process WHEREIN: It reduces using coal, The purification method characterized by the above-mentioned. The purification method according to any one of claims 6 to 14 ,
In the purification step, the nickel compound or the cobalt compound from which the sulfur or the chlorine has been removed is purified using an electric furnace. The purification method according to any one of claims 1 to 15 ,
Purifying the oxide ore containing nickel or cobalt by leaching with sulfuric acid to obtain a nickel compound or cobalt compound, and then performing the step of obtaining the slurry using the obtained nickel compound or cobalt compound Method. A production method for producing ferronickel from iron and a nickel compound,
Carrying out the purification method according to any one of claims 1 to 4 using a nickel compound as a raw material, and obtaining the nickel compound by the filtration step;
A step of reducing the iron and the nickel compound by performing a heat treatment in a state where the nickel compound and iron coexist;
Obtaining ferronickel by melting the reduced iron and the nickel compound;
A process for producing ferronickel, comprising:

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