CN113621831A

CN113621831A - Method for extracting nickel from laterite-nickel ore

Info

Publication number: CN113621831A
Application number: CN202110918512.6A
Authority: CN
Inventors: 林晓; 赵金风; 张志华; 王雪; 刘刚锋
Original assignee: Suzhou Bocui Recycling Technology Co ltd; Gusu Laboratory of Materials
Current assignee: Suzhou Bocui Recycling Technology Co ltd
Priority date: 2021-08-12
Filing date: 2021-08-12
Publication date: 2021-11-09

Abstract

The invention discloses a method for extracting nickel from laterite-nickel ore, which comprises the following steps: (1) carrying out extraction and impurity removal treatment on the laterite-nickel ore leaching solution by using an impurity removal agent, and separating to obtain a first water phase and iron-aluminum slag; (2) extracting the first aqueous phase by using a first extracting agent, and separating to obtain an organic phase and a second aqueous phase loaded with impurities; (3) saponifying the second extracting agent by using a saponifying agent, and extracting the second aqueous phase by using the saponified second extracting agent to obtain a nickel-loaded organic phase and a third aqueous phase; (4) washing and back-extracting the organic phase loaded with nickel in sequence to obtain nickel salt; wherein at least part of the edulcorant and/or saponifier is derived from the third aqueous phase. According to the invention, magnesium oxide is used as a saponifier, so that high-efficiency nickel extraction of high-magnesium systems such as laterite-nickel ore leaching solution and the like can be realized, the process is simple, the magnesium oxide and the like can be recycled, the energy is saved, the environment is protected, and the cost is low.

Description

Method for extracting nickel from laterite-nickel ore

The technical field is as follows:

the invention relates to a method for extracting nickel from laterite-nickel ore, in particular to a method for extracting nickel from laterite-nickel ore, belonging to the technical field of hydrometallurgy.

Background

Nickel is used as a necessary metal material for generating a new energy automobile power battery, and reaches the carbon neutralization target after 2060 years of promise in China, so that the environment-friendly and clean new energy automobile has a new revolution, which inevitably requires the improvement of the utilization technology of nickel metal. At present, the sources of nickel resources mainly comprise nickel sulfide ores and nickel laterite ores, wherein the worldwide reserve of nickel ores is 70 percent of that of nickel laterites, and as the nickel sulfide ores are exploited and utilized worldwide, the development and utilization of nickel laterite ores are gradually paid attention by researchers and markets, so that the development of more economical and efficient technologies is of great importance.

At present, the process for extracting nickel from laterite-nickel ore comprises the pyrometallurgical and hydrometallurgical processes. Among them, the pyrometallurgical process is limited in application due to the problems of large energy consumption, serious air pollution and the like. The hydrometallurgical process has become the mainstream trend of the application of the laterite nickel ore due to the characteristics of capability of preparing high-purity products, low operation cost, high automation and the like, and has wide application prospect.

One existing process uses a P204/P507 extraction system to extract nickel, but this approach is more difficult to purify nickel in high magnesium systems. Aiming at the problems, an improved process is that an alkaline compound is adopted to precipitate a solution containing nickel, cobalt and magnesium to generate a nickel-cobalt intermediate product containing less magnesium, and the nickel-cobalt intermediate product is extracted and purified by using P204/P507 after being leached, however, the process needs to be precipitated and leached again, the process is complex, the requirement on equipment is high, and the treatment cost of the laterite-nickel ore can be greatly increased. CN109881006A discloses a method for purifying nickel sulfate solution, wherein the pH of the desorption solution recovered from the lateritic nickel ore leaching solution by resin method is firstly adjusted, then iron and arsenic are removed by hydrogen peroxide oxidation method, calcium and magnesium ions in sodium fluoride precipitation system are utilized, the filtrate is sequentially passed through a resin tower containing p204 resin and cyanex272 resin to respectively remove copper, lead, zinc, manganese and cobalt, finally the saponified p204 resin is used to extract nickel in the solution, and then sulfuric acid is used for back extraction to obtain high-purity nickel sulfate solution. CN101532094A discloses a process for extracting and separating nickel and cobalt from an acid raw material system with high content of calcium and magnesium impurities in the whole process, which comprises a P204 impurity removal process line, a P507 cobalt fishing process line and a P507 magnesium fishing process line which are sequentially carried out. However, these processes all have the defects of complicated flow, high cost and the like.

Object of the Invention

The invention mainly aims to provide a method for extracting nickel from laterite-nickel ore so as to overcome the defects in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

the embodiment of the invention provides a method for extracting nickel from laterite-nickel ore, which comprises the following steps:

(1) carrying out extraction and impurity removal treatment on the laterite-nickel ore leaching solution by using an impurity removal agent, and separating to obtain a first water phase and iron-aluminum slag;

(2) extracting the first aqueous phase by using a first extracting agent, and separating to obtain an organic phase and a second aqueous phase loaded with impurities;

(3) saponifying the second extracting agent by using a saponifying agent, and extracting the second aqueous phase by using the saponified second extracting agent to obtain a nickel-loaded organic phase and a third aqueous phase;

(4) washing and back-extracting the organic phase loaded with nickel in sequence to obtain nickel salt;

wherein at least part of the edulcorant and/or saponifier is derived from the third aqueous phase.

In some embodiments, the laterite-nickel ore leach liquor in step (1) comprises: ni is 2-20 g/L, Co-1-5 g/L, Mg-5-50 g/L, Fe-10 g/L, Zn-1-10 g/L, Al-1-10 g/L, Cu-0.01-10 g/L, Cd-0.01-10 g/L.

In some embodiments, the pH of the first aqueous phase in step (1) is from 1.5 to 4.

In some embodiments, the amount of iron and aluminum in the first aqueous phase in step (1) is 0.2g/L or less.

In some embodiments, the first extractant in step (2) comprises BC196 or P204, preferably BC 196.

In some embodiments, step (2) comprises: the first aqueous phase is subjected to an extraction treatment with a first extraction organic phase comprising a saponified first extraction agent and a diluent.

Further, the diluent includes any one of diluent Escaid 110, mineral spirit, heptane, dodecane, or kerosene, or a combination of at least two thereof, and is not limited thereto. Wherein the diluent is preferably Escaid 110 and/or dodecane. Among them, the dodecane is preferably n-dodecane.

Further, the first extraction organic phase contains 5-30V/V% of a first extracting agent.

Preferably, the volume ratio of the first extraction organic phase to the first aqueous phase is 1: 0.1 to 10, such as 1: 0.1, 1: 0.5, 1: 1, 1: 2, 1: 5, or 1: 10, and the like, as well as specific points therebetween.

In some embodiments, step (2) comprises: the extraction stage number of the first aqueous phase by using the first extracting agent is 2-10.

In some embodiments, step (2) comprises: the first extraction agent is saponified by a saponifying agent, and then the first aqueous phase is extracted by the saponified first extraction agent.

Preferably, the mixing time of the saponifying agent and the first extracting agent in the saponification treatment process is 15-60 min.

In some embodiments, step (2) comprises: the organic phase loaded with impurities is washed with an inorganic acid or purified water, followed by stripping with a first stripping agent.

Further, the inorganic acid includes hydrochloric acid or sulfuric acid. Preferably, the concentration of the hydrochloric acid or the sulfuric acid is 0.1-1.0 mol/L.

Furthermore, in the step (2), the washing grade of the organic phase loaded with the impurities is 5-15 grades by using inorganic acid or purified water. Preferably, the pH value of a washing water phase obtained after washing the organic phase loaded with the impurities by using inorganic acid or purified water is controlled to be 2.5-4.

Further, the first stripping agent comprises hydrochloric acid. Preferably, the concentration of the hydrochloric acid is 2-6 mol/L.

Further, the back extraction stage number of the back extraction in the step (2) is preferably 5-10.

In some embodiments, step (3) comprises: and (3) deoiling the second aqueous phase, and then extracting the second aqueous phase by using a saponified second extracting agent.

In some embodiments, the amount of the saponification unit used in the saponification treatment in step (3) is 0.2 to 0.5 mol/L.

In some embodiments, the second extractant in step (3) comprises a carboxylic acid extractant. Preferably, the carboxylic acid extractant includes BC 196.

In some embodiments, step (3) comprises: and carrying out multi-stage countercurrent fractional extraction on the second aqueous phase by using the saponified second extracting agent. Preferably, the extraction stages of the multistage countercurrent fractional extraction are 5-15 stages.

In some embodiments, step (3) comprises: and (c) subjecting the second aqueous phase to an extraction treatment with a second extraction organic phase comprising a saponified second extraction agent and a diluent.

Further, the diluent includes any one of diluent Escaid 110, mineral spirit, heptane, dodecane, or kerosene, or a combination of at least two thereof, and is not limited thereto. Preferably, the diluent is Escaid 110 and/or dodecane. More preferably, the dodecane is n-dodecane.

Further, the second extraction organic phase contains 5-30V/V% saponified second extracting agent.

In some embodiments, the nickel content in the third aqueous phase of step (3) is 0.005g/L or less.

In some embodiments, the trash or saponifier includes magnesium oxide. Preferably, at least part of the magnesium oxide is derived from the third aqueous phase. Preferably, the magnesium oxide comprises any one or combination of more of active magnesium oxide, light magnesium oxide and heavy magnesium oxide.

Preferably, the magnesium oxide is used as a magnesium oxide slurry. Further preferably, the magnesium oxide slurry comprises 2-200 g/L of MgO, such as: 2g/L, 5g/L, 10g/L, 15g/L, 20g/L, 25g/L, 50g/L, 100g/L, 150g/L, or 200g/L, etc., as well as specific points therebetween.

In some embodiments, step (4) comprises: and (3) carrying out acid washing on the organic phase loaded with the nickel by using inorganic acid. Further, the inorganic acid comprises one or a mixture of two of hydrochloric acid and sulfuric acid. Preferably, the inorganic acid comprises hydrochloric acid and sulfuric acid in a volume ratio of 1: 1.

Preferably, step (4) comprises: and (4) using the washing liquid generated by acid washing to prepare the laterite-nickel ore leaching liquid or combining the washing liquid with the third water obtained in the step (3).

Further, the step (4) further comprises: and washing the organic phase loaded with the nickel after the inorganic acid washing with pure water.

In some embodiments, the number of washing steps of the washing treatment in step (4) is 5 to 20.

In some embodiments, step (4) comprises: and (4) carrying out back extraction on the washed nickel-loaded organic phase by using a second back extractant, and separating to obtain a nickel salt solution and a raffinate organic phase. Further, the content of magnesium in the nickel salt solution is less than 0.010 g/L. Further, the content of nickel in the raffinate organic phase is less than or equal to 0.005 g/L. Further, the second stripping amount comprises sulfuric acid. Preferably, the concentration of the sulfuric acid is 2-3.5 mol/L.

Further, the method further comprises: and (3) regenerating the raffinate organic phase obtained in the step (4) and then using the regenerated raffinate organic phase in the step (2) and/or the step (3).

In some embodiments, the stripping number of the stripping treatment in the step (4) is 5 to 10.

In some embodiments, the method further comprises: and (3) applying the organic phase partially loaded with nickel obtained in the step (3) as the first extracting agent in the step (2) to perform extraction treatment on the first aqueous phase.

Preferably, BC196 is used for both the first extractant and the second extractant.

In some embodiments, the method further comprises: subjecting the third aqueous phase to a pyrolysis spray treatment to obtain a trash remover and/or a saponifier.

Further, the impurity removing agent and the saponifying agent comprise magnesium oxide, and the third water phase comprises magnesium chloride.

In some embodiments, the method further comprises: and (4) carrying out pyrolysis spraying treatment on the third water phase to obtain inorganic acid, and using the obtained inorganic acid to prepare laterite-nickel ore leaching liquid or washing the nickel-loaded organic phase in the step (4). Further, the inorganic acid is hydrochloric acid.

The method for extracting nickel from the laterite-nickel ore provided by the embodiment of the invention specifically comprises the following steps:

(1) extracting and purifying the laterite-nickel ore leaching solution by using magnesium oxide, and separating to obtain a first water phase and iron-aluminum slag;

(2) extracting the first water phase by using a first extracting agent, separating to obtain an organic phase loaded with impurities and a second water phase, and sequentially washing and back-extracting the organic phase loaded with the impurities;

(3) saponifying the second extracting agent by using magnesium oxide, and extracting the deoiled second aqueous phase by using the saponified second extracting agent to obtain a nickel-loaded organic phase and a third aqueous phase, wherein the third aqueous phase contains magnesium chloride;

(4) sequentially carrying out acid washing and water washing treatment on the organic phase loaded with nickel, and then carrying out back extraction treatment to obtain nickel salt;

and, the method further comprises: and (3) carrying out spray pyrolysis treatment on the third water phase, recycling the obtained magnesium oxide for the step (1) and/or the step (2) and/or the step (3), and using the obtained hydrochloric acid for preparing laterite-nickel ore leaching liquid and/or for carrying out back extraction treatment on the organic phase loaded with impurities in the step (2) and/or for carrying out acid washing treatment on the organic phase loaded with nickel in the step (4).

Compared with the prior art, the method for extracting nickel from the laterite-nickel ore can purify nickel aiming at a high-magnesium system, does not need a process of precipitating and removing magnesium, simplifies the process, saves acid and alkali expenses, reduces the cost by using cheap and easily-obtained magnesium oxide as a saponifiable matter, realizes recycling of materials such as magnesium oxide in the process, reduces the discharge of waste, and is green and environment-friendly.

Drawings

Fig. 1 is a schematic illustration of a method of extracting nickel from lateritic nickel ores in an exemplary embodiment of the invention.

Detailed Description

The method for extracting nickel from the laterite-nickel ore comprises the following steps:

(1) processing the laterite-nickel ore by adopting modes such as hydrochloric acid atmospheric pressure leaching and the like to obtain laterite-nickel ore leachate, neutralizing the laterite-nickel ore leachate by using magnesium oxide, precipitating to remove impurities such as iron and aluminum, and processing by using a plate-and-frame filter press to obtain filtrate and filter residue, wherein the filtrate is defined as a first water phase, and the filter residue is iron and aluminum residue;

(2) extracting the first aqueous phase by adopting P204, BC196 and the like to remove impurities such as zinc, copper and the like in the first aqueous phase, and separating to obtain an organic phase and a second aqueous phase which are loaded with the impurities;

(3) deoiling the second water phase, and performing multi-stage countercurrent extraction on the deoiled second water phase by using saponified BC196 to obtain a nickel-loaded organic phase and a third water phase, wherein the saponified BC196 is obtained by saponifying the BC196 by using magnesium oxide, and the third water phase contains magnesium chloride;

(4) washing and back extracting the organic phase loaded with nickel in sequence to obtain a nickel salt product;

wherein the third aqueous phase may be subjected to spray pyrolysis to obtain magnesium oxide, and the obtained magnesium oxide may be recycled to step (1) and/or step (3), so that recycling of magnesium may be completed.

Further, the laterite-nickel ore leaching solution in the step (1) comprises the following steps: ni is 2-20 g/L, Co-1-5 g/L, Mg-5-50 g/L, Fe-10 g/L, Zn-1-10 g/L, Al-1-10 g/L, Cu-0.01-10 g/L, Cd-0.01-10 g/L. Ni, Co, Mg, Fe, Zn, Al, Cu and Cd in the laterite-nickel ore leaching solution mainly exist in the form of ions.

Further, the magnesium oxide obtained in the step (1) and/or the step (3) is high-purity magnesium oxide formed by pyrolysis and spraying of the third aqueous phase obtained in the step (3).

Further, the magnesium oxide may be any one of active magnesium oxide, light magnesium oxide, heavy magnesium oxide, or a combination of at least two thereof.

Further, the magnesium oxide is prepared as a magnesium oxide slurry having a concentration of 2 to 200g/L (MgO amount).

Further, the pH value of the first water phase in the step (1) is 1.5-4.

Further, the content of iron and aluminum in the first aqueous phase in the step (1) is less than or equal to 0.2 g/L.

Furthermore, the volume ratio of the first extraction organic phase containing the high-purity P204 to the first water phase in the step (2) is 1: 0.1-10, and the number of extraction stages is 2-10. Corresponding extraction modes include, but are not limited to, multi-stage countercurrent fractional extraction and the like.

Further, in order to reduce the loading of nickel, the step (2) further comprises: and washing the organic phase loaded with impurities and then performing back extraction.

Among them, the organic phase loaded with impurities may be washed using hydrochloric acid, purified water, sulfuric acid, or the like as a detergent.

Preferably, the concentration of the hydrochloric acid or the sulfuric acid as the detergent is 0.1-1.0 mol/L.

Preferably, the washing grade for washing the organic phase loaded with the impurities is 5-15 grades.

Preferably, the pH value of a washing liquid (water phase) generated by washing the organic phase loaded with the impurities is controlled to be 2.5-4.

More preferably, if hydrochloric acid is used as a washing agent, washing liquid generated by washing can be reused for preparing the laterite nickel ore leaching liquid.

Preferably, the washed organic phase loaded with impurities is stripped using hydrochloric acid as stripping agent.

More preferably, the concentration of the hydrochloric acid used as the stripping agent is 2-6 mol/L.

More preferably, hydrochloric acid is used as a stripping agent to strip the washed organic phase loaded with the impurities, wherein the stripping grade is 5-10 grades.

Further, the step (3) may specifically include saponification, extraction, washing, stripping, and the like.

Wherein the amount of the saponification unit for saponifying BC196 is preferably 0.2-0.5 mol/L.

The saponified BC196 may be diluted with a diluent or the like to form a second organic extraction phase, and the second organic extraction phase may be used to extract the second aqueous phase.

Preferably, the saponified BC196 is present in the second organic extract in an amount of 5-30% by volume, e.g., 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 21%, 23%, 25%, 27%, or 30%, and the specific values therebetween, including for brevity and clarity, are not exhaustive.

Preferably, the extraction mode in the step (3) can be multi-stage countercurrent fractional extraction.

Preferably, in the multi-stage countercurrent fractional extraction in the step (3), the extraction stage number is 5-15 stages, the washing stage number is 5-20 stages, and the back extraction stage number is 5-10 stages.

Preferably, the content of nickel in the third aqueous phase in the step (3) is less than or equal to 0.005 g/L.

Further, the detergent used for washing the nickel-loaded organic phase in the step (4) can be one or a mixture of two of hydrochloric acid and sulfuric acid.

Preferably, step (4) uses a mixture of hydrochloric acid and sulfuric acid as a detergent, and the volume ratio of the hydrochloric acid to the sulfuric acid is 1: 1.

More preferably, hydrochloric acid is used as a washing agent in the step (4), the concentration of the hydrochloric acid is 0.1-1 mol/L, and the washing grade is 5-15. The hydrochloric acid may be obtained after spray pyrolysis of said third aqueous phase. And the washing liquid generated after the hydrochloric acid washing can be returned to the leaching section to prepare the laterite-nickel ore leaching liquid, and can also be merged into the extraction section, namely is merged with the third water phase.

More preferably, in the step (4), after the organic phase loaded with nickel is washed by hydrochloric acid, pure water is used for washing chlorine in the organic phase loaded with nickel, and the number of washing stages is 2-5.

Preferably, the step (4) can use sulfuric acid as a stripping agent to strip the washed nickel-loaded organic phase. And the content of magnesium in the nickel sulfate solution obtained after back extraction is less than 0.010 g/L.

Preferably, after the back extraction in the step (4) is completed, the separated raffinate organic phase can be regenerated and recycled.

The extraction equipment involved in this exemplary embodiment includes a combination of one or more of a mixer-settler, an extraction column, a centrifugal extractor, and is not limited thereto.

Further, step (2) preferably uses BC196 as an extracting agent, so that the ganged extraction can be realized in the method, that is, the organic phase partially loaded with nickel obtained in step (3) can be used for removing impurities in step (2), so that the liquid consumption of the organic phase in the method is reduced, and the acid-base cost is saved.

The method for extracting nickel from the laterite-nickel ore provided by the typical embodiment has the advantages of short process flow, environmental protection, economy, cost saving and the like.

Referring to fig. 1, another method for extracting nickel from lateritic nickel ore provided by the second embodiment of the present invention is substantially the same as the first embodiment except that:

in the step (2), high-purity extractants such as BC196 and P204 are subjected to magnesium saponification, and then the first water phase is subjected to extraction and impurity removal by using the extractants subjected to magnesium saponification.

Furthermore, magnesium oxide is used for magnesium saponification in the step (2), and particularly the high-purity magnesium oxide formed by pyrolysis and spraying of the third aqueous phase obtained in the step (3) is adopted.

Preferably, the magnesium oxide can be any one of active magnesium oxide, light magnesium oxide, heavy magnesium oxide or a combination of at least two of the above.

Preferably, magnesium oxide slurry is used for magnesium saponification in step (2). And wherein the pulping may be batch-wise proportioned using pure water and magnesia. More preferably, the concentration of the magnesium oxide slurry may be 2 to 200g/L (MgO content). More preferably, in the magnesium saponification in the step (2), the mixing time of the magnesium oxide slurry and the high-purity extractant is 15-60 min.

Further, in the step (2), the saponified extractant may be diluted with a diluent or the like to form a first organic extraction phase, and the first organic extraction phase may be used to perform extraction with respect to the first aqueous phase. Preferably, the saponified BC196 is present in the second organic extract phase in an amount of 5-30% by volume, e.g., 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 21%, 23%, 25%, 27%, or 30%, and specific points therebetween. Preferably, the diluent comprises any one of diluent Escaid 110, mineral spirit, heptane, dodecane or kerosene, or a combination of at least two thereof; more preferably Escaid 110 and/or dodecane (e.g. n-dodecane).

In the above embodiment of the invention, hydrochloric acid is preferably used as the leaching agent for the laterite-nickel ore leaching solution, and meanwhile, a BC196 extractant is preferably used, the extraction sequence is nickel, cobalt, manganese, calcium and magnesium, and is different from the extraction sequence (cobalt → magnesium → nickel) of the existing extractants P204 and P507, so that the interference of calcium and magnesium in a high-magnesium system on nickel and cobalt separation can be effectively avoided, the nickel can be efficiently extracted, and the process is energy-saving, efficient, green and environment-friendly.

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1 a process for the extraction of nickel from lateritic nickel ores, wherein a treated lateritic nickel ore hydrochloric acid atmospheric leach solution (hereinafter referred to simply as lateritic nickel ore leach solution) is obtained by atmospheric leaching of lateritic nickel ores with hydrochloric acid and has the following composition:

element(s)	Ni	Co	Fe	Al	Zn	Cu	Mg	Ca	pH value
										Content (g/L)	11.8	0.5	18.3	15.6	0.48	0.5	21.5	5.2	1.2

i. under the condition that the temperature is about 40 ℃, magnesium oxide slurry with the concentration of 20g/L is stirred and mixed with the laterite-nickel ore leaching solution, the mixing time is 2 hours, after the reaction is finished, a plate-and-frame filter press is used for carrying out solid-liquid separation to obtain filtrate with the pH value of 2.0 and iron-aluminum slag, the iron-aluminum content in the filtrate is less than 0.1g/L, and the filtrate enters an impurity removal section;

ii, the first and second substrates are coated with a coating, a mixed clarifying tank is used in the impurity removing section, a saponified BC196 extracting agent (containing 15% by volume of BC196, wherein a diluent is sulfonated kerosene, magnesium oxide slurry with the concentration of 20g/L is saponified, the amount of a saponified single is 0.1mol/L, the saponification time is 30min) is adopted, the volume ratio of a feed liquid to an organic phase is 2: 1, the extraction stage number is 6, then the loaded Cu-Mn organic phase is separated from the raffinate rich in nickel and cobalt, hydrochloric acid with the concentration of 0.1mol/L is used as a washing agent to wash the loaded Cu-Mn organic phase, the volume ratio of the washing agent to the organic phase is 1: 8, the washing stage number is 10, then hydrochloric acid with the concentration of 4mol/L is used as a stripping agent to strip the loaded Cu-Mn organic phase, the volume ratio of the stripping agent to the organic phase is 15: 1, and the stripping stage number is 6, so that a Cu-Mn-rich solution is obtained, and the raffinate rich in nickel and cobalt enters a nickel extracting section;

iii, a mixed clarifying tank is used in a nickel extraction section, a saponified extractant BC196 (containing 25% by volume BC 196) is adopted, wherein a diluent is sulfonated kerosene, a saponifying agent is 15g/L magnesium oxide slurry, the amount of a saponified single phase is 0.36mol/L, the saponification time is 30min), the volume ratio of a feed liquid to an organic phase is 1: 1, the extraction stage number is 6 stages, then a nickel-loaded organic phase is separated from a raffinate rich in magnesium chloride, hydrochloric acid with the concentration of 0.5mol/L is used as a detergent for washing the nickel-loaded organic phase, the volume ratio of the detergent to the organic phase is 1: 10, the washing stage number is 7 stages, then sulfuric acid with the concentration of 2mol/L is used as a stripping agent for carrying out stripping on the nickel-loaded organic phase, the volume ratio of the stripping agent to the organic phase is 15: 1, the stripping stage number is 6 stages, a nickel sulfate solution product is obtained, the raffinate rich in magnesium chloride enters pyrolysis spray, and (3) obtaining a magnesium oxide product and a hydrochloric acid product, wherein the magnesium oxide product can be used as a saponifying agent in the working sections of impurity removal, nickel extraction and the like, and the hydrochloric acid product can be used for preparing the laterite nickel ore leaching solution or can be reused in the step ii or the step iii.

The experimental results are as follows: the nickel content in the nickel sulfate solution is 118g/L, the magnesium content is 0.007g/L, the nickel content in the magnesium chloride solution for pyrolysis spraying is less than 0.005g/L, and the nickel metal recovery rate is 99.75%.

Example 2 a process for the extraction of nickel from lateritic nickel ores, where the leach solution of the lateritic nickel ore being treated is obtained by atmospheric leaching of the lateritic nickel ore using hydrochloric acid and the composition of which is given in the following table:

element system	Ni	Co	Fe	Al	Zn	Cu	Mg	Ca	pH value
										Content (g/L)	11.8	0.5	18.3	15.6	0.48	0.5	21.5	5.2	1.2

i. under the condition that the temperature is about 65 ℃, stirring and mixing magnesium oxide slurry with the concentration of 20g/L with the laterite-nickel ore leaching solution for 2 hours, carrying out solid-liquid separation by using a plate-and-frame filter press after the reaction is finished to obtain filtrate with the pH value of 2.0 and iron-aluminum slag, wherein the iron-aluminum content in the filtrate is less than 0.1g/L, and the filtrate enters an impurity removal section;

ii, the first and second substrates are coated with a coating, a mixing clarifying tank is used in the impurity removing section, a saponified P204 extracting agent (containing 15% of P204 by volume fraction, wherein the diluent is Escaid 110, magnesium oxide slurry with the concentration of 15g/L is saponified, the amount of a saponified single is 0.1mol/L, the saponification time is 30min) is adopted, the volume ratio of a feed liquid to an organic phase is 2: 1, the extraction stage number is 4, then the loaded copper-manganese organic phase is separated from the raffinate rich in nickel and cobalt, hydrochloric acid with the concentration of 0.5mol/L is used as a washing agent to wash the loaded copper-manganese organic phase, the volume ratio of the washing agent to the organic phase is 1: 10, the washing stage number is 8, then hydrochloric acid with the concentration of 4mol/L is used as a stripping agent to carry out stripping on the loaded copper-manganese organic phase, the volume ratio of the stripping agent to the organic phase is 15: 1, the stripping stage number is 5, a solution rich in copper and manganese is obtained, and the raffinate rich in nickel and cobalt enters a nickel extracting section;

iii, a mixed clarifying tank is used in a nickel extraction section, saponified extractant BC196 (containing 25% BC196 by volume, wherein the diluent is Escaid 110, the saponifying agent is magnesium oxide slurry with the concentration of 15g/L, the saponification amount is 0.38mol/L, the saponification time is 15min), the volume ratio of feed liquid (namely the raffinate rich in nickel and cobalt) to an organic phase is 1: 1, the stage number is 6, then the loaded nickel organic phase is separated from the raffinate rich in magnesium chloride, hydrochloric acid with the concentration of 0.5mol/L is used as a detergent to wash the loaded nickel organic phase, the volume ratio of the detergent to the organic phase is 1: 10, the washing stage number is 7, then sulfuric acid with the concentration of 2mol/L is used as a stripping agent to strip the loaded nickel organic phase, the volume ratio of the stripping agent to the organic phase is 15: 1, and the stripping stage number is 6, so as to obtain a nickel sulfate solution product, and (3) carrying out pyrolysis spraying on the raffinate rich in the magnesium chloride to obtain a magnesium oxide product and a hydrochloric acid product, wherein the magnesium oxide product can be used as a saponifying agent for impurity removal, nickel extraction and other working sections, and the hydrochloric acid product can be used for preparing the laterite nickel ore leachate or can be reused in the step ii or the step iii.

The experimental results are as follows: the nickel content in the nickel sulfate solution is 120g/L, the magnesium content is 0.005g/L, the nickel content in the magnesium chloride solution for pyrolysis spraying is less than 0.003g/L, and the nickel metal recovery rate is 99.82%.

Example 3 a process for the extraction of nickel from lateritic nickel ores, where the leach solution of the lateritic nickel ore being treated is obtained by atmospheric leaching of the lateritic nickel ore using hydrochloric acid and the composition of which is given in the following table:

element system	Ni	Co	Fe	Al	Zn	Cu	Mg	Ca	pH value
										Content (g/L)	5	0.05	31.2	23.1	0.63	0.89	40.5	8.3	1.2

i. under the condition that the temperature is about 80 ℃, magnesium oxide slurry with the concentration of 40g/L is stirred and mixed with the laterite-nickel ore leaching solution, the mixing time is 1.5h, a plate-and-frame filter press is used for carrying out solid-liquid separation after the reaction is finished, filtrate with the pH value of 1.95 and iron-aluminum slag are obtained, the iron-aluminum content in the filtrate is less than 0.15g/L, and the filtrate enters an impurity removal section;

ii. A mixing clarifying tank is used in the impurity removal section, a saponified BC196 extracting agent (containing 15% of P204 by volume fraction, wherein the diluent is Escaid 110, magnesium oxide slurry with the concentration of 25g/L is saponified, the saponification amount is 0.14mol/L, the saponification time is 30min) is adopted, the volume ratio of feed liquid to an organic phase is 4: 1, the extraction stage number is 6, then the loaded copper-manganese organic phase is separated from raffinate rich in nickel and cobalt, hydrochloric acid with the concentration of 0.5mol/L is used as a detergent for washing the loaded copper-manganese organic phase, the volume ratio of the detergent to the organic phase is 1: 10, the washing stage number is 6, then hydrochloric acid with the concentration of 4mol/L is used as a stripping agent for carrying out stripping on the loaded copper-manganese organic phase, the volume ratio of the stripping agent to the organic phase is 15: 1, the stripping stage number is 5, and a copper-manganese rich solution is obtained after the stripping of the loaded copper-manganese organic phase, the raffinate rich in nickel and cobalt enters a nickel extraction section;

iii, a mixed clarifying tank is used in a nickel extraction section, saponified extractant BC196 (containing 25% BC196 by volume fraction, wherein the diluent is Escaid 110, the saponifying agent is 15g/L magnesium oxide slurry, the saponification amount is 0.38mol/L, the saponification time is 15min), the volume ratio of feed liquid to organic phase is 1: 1, the extraction stage number is 5 stages, then the nickel-loaded organic phase is separated from the raffinate rich in magnesium chloride, one part of the obtained nickel-loaded organic phase is used as the extractant in an impurity removal section to realize linkage extraction, the other nickel-loaded organic phases are washed (hydrochloric acid with the concentration of 0.5mol/L is used as the detergent, the volume ratio of the detergent to the organic phase is 1: 10, the washing stage number is 8 stages), and back extraction (sulfuric acid with the concentration of 2mol/L is used as the back extractant, the volume ratio of the back extractant to the organic phase is 15: 1, the number of the back extraction stages is 6) to obtain a nickel sulfate solution product, the raffinate rich in magnesium chloride enters pyrolysis spraying to obtain a magnesium oxide product and a hydrochloric acid product, the magnesium oxide product can be used as a saponifier in the working sections of impurity removal, nickel extraction and the like, and the hydrochloric acid product can be used for preparing the laterite nickel ore leachate or can be reused in the step ii or the step iii.

The experimental results are as follows: the nickel content in the nickel sulfate solution is 115g/L, the magnesium content is 0.005g/L, the nickel content in the magnesium chloride solution for pyrolysis spraying is less than 0.0005g/L, and the nickel metal recovery rate is 99.9%.

In addition, the inventor also refers to the schemes of examples 1-3, and experiments are carried out under other process conditions mentioned in the invention, and the results show that the nickel can be efficiently extracted from a high-magnesium system.

Comparative example 1 this comparative example provides a method for extracting nickel from lateritic nickel ores that is substantially the same as example 1, except that: in step iii, a saponified extractant P507 (containing 25% by volume of P507, wherein the diluent is sulfonated kerosene, the saponifier is magnesium oxide slurry with the concentration of 15g/L, the amount of a saponified monomer is 0.36mol/L, and the saponification time is 30min) is adopted, and other conditions are not changed.

The experimental results are as follows: the nickel content in the nickel sulfate solution is 105g/L, the magnesium content is 5g/L, the nickel content in the magnesium chloride solution for pyrolysis spraying is 0.5g/L, and the nickel metal recovery rate is 95.83%.

In the above embodiment of the invention, the magnesium oxide which is cheap and easy to obtain is adopted as the saponifying agent, so that the nickel extraction of a high-magnesium system can be realized without operations such as precipitation and magnesium removal, the nickel extraction efficiency of the laterite-nickel ore leaching solution can be obviously improved, and the magnesium oxide, the hydrochloric acid, the organic solvent and the like can be recycled in the process, thereby saving energy and protecting environment.

It should be noted that the above mentioned embodiments are only specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope of the present invention and the disclosure.

Claims

1. A method for extracting nickel from laterite-nickel ore is characterized by comprising the following steps:

2. The method according to the claim 1, characterized in that the laterite-nickel ore leaching liquor in step (1) contains: 2-20 g/L, Co, 1-5 g/L, Mg, 5-50 g/L, Fe, 10-80 g/L, Zn, 1-10 g/L, Al, 1-10 g/L, Cu, 0.01-10 g/L, Cd, 0.01-10 g/L; and/or the pH value of the first water phase in the step (1) is 1.5-4; and/or the content of iron and aluminum in the first aqueous phase in the step (1) is less than or equal to 0.2 g/L.

3. The method of claim 1, wherein:

the first extractant in step (2) comprises BC196 or P204;

and/or, the step (2) comprises: subjecting the first aqueous phase to an extraction treatment with a first extraction organic phase comprising a saponified first extraction agent and a diluent;

preferably, the diluent comprises any one of diluent Escaid 110, mineral spirit, heptane, dodecane or kerosene, or a combination of at least two thereof; further, the diluent is preferably Escaid 110 and/or dodecane; preferably, the dodecane is n-dodecane;

preferably, the first extraction organic phase comprises 5-30V/V% of a first extractant;

preferably, the volume ratio of the first extraction organic phase to the first aqueous phase is 1: 0.1-10;

preferably, the extraction stage number of the first aqueous phase by using the first extracting agent is 2-10;

and/or, the step (2) comprises: firstly, saponifying a first extracting agent by using a saponifying agent, and then extracting the first aqueous phase by using the saponified first extracting agent; preferably, the mixing time of the saponifying agent and the first extracting agent in the saponification treatment process is 15-60 min.

4. The method of claim 1, wherein step (2) comprises: washing the organic phase loaded with impurities with inorganic acid or purified water, and then performing back extraction with a first back extractant;

preferably, the inorganic acid comprises hydrochloric acid or sulfuric acid; more preferably, the concentration of the hydrochloric acid or the sulfuric acid is 0.1-1.0 mol/L; preferably, the washing grade of washing the organic phase loaded with the impurities by using inorganic acid or purified water is 5-15 grades; preferably, the pH value of a washing water phase obtained after washing the organic phase loaded with the impurities by using inorganic acid or purified water is controlled to be 2.5-4;

preferably, the first stripping agent comprises hydrochloric acid, the concentration of the hydrochloric acid is 2-6 mol/L, and the stripping grade number of the stripping is 5-10.

5. The method of claim 1, wherein:

the step (3) comprises the following steps: firstly, carrying out oil removal treatment on the second aqueous phase, and then carrying out extraction treatment on the second aqueous phase by using a saponified second extracting agent;

and/or the amount of the saponification unit adopted in the saponification treatment in the step (3) is 0.2-0.5 mol/L;

and/or, the second extractant in step (3) comprises a carboxylic acid extractant, preferably, the carboxylic acid extractant comprises BC 196;

and/or, the step (3) comprises: performing multi-stage countercurrent fractional extraction on the second aqueous phase by using the saponified second extracting agent; preferably, the extraction stages of the multistage countercurrent fractional extraction are 5-15 stages;

and/or, the step (3) comprises: subjecting the second aqueous phase to an extraction treatment with a second extraction organic phase comprising a saponified second extraction agent and a diluent;

preferably, the second extraction organic phase contains 5-30V/V% saponified second extractant;

and/or the content of nickel in the third aqueous phase in the step (3) is less than or equal to 0.005 g/L.

6. The method according to any one of claims 1-5, wherein: the impurity removing agent and the saponifying agent comprise magnesium oxide, and at least part of the magnesium oxide is sourced from the third water phase; preferably, the magnesium oxide comprises any one or more of active magnesium oxide, light magnesium oxide and heavy magnesium oxide; preferably, the magnesium oxide is prepared into magnesium oxide slurry for use; further preferably, the magnesium oxide slurry contains 2-200 g/L of MgO.

7. The method of claim 1, wherein step (4) comprises: pickling the organic phase loaded with the nickel by using inorganic acid; preferably, the inorganic acid comprises one or a mixture of two of hydrochloric acid and sulfuric acid; preferably, the inorganic acid comprises hydrochloric acid and sulfuric acid in a volume ratio of 1: 1;

preferably, the nickel-loaded organic phase after the inorganic acid washing is further washed with pure water; preferably, the washing liquid generated by acid washing is also used for preparing the leaching liquid of the laterite-nickel ore or the acid washing configuration.

And/or the washing grade number of the washing treatment in the step (4) is 5-20 grades;

and/or, the step (4) comprises: carrying out back extraction on the washed nickel-loaded organic phase by using a second back extractant, and separating to obtain a nickel salt solution and a raffinate organic phase; preferably, the second stripping amount comprises sulfuric acid; more preferably, the concentration of the sulfuric acid is 2-3.5 mol/L; preferably, the content of magnesium in the nickel salt solution is less than 0.010 g/L; preferably, the content of nickel in the raffinate organic phase is less than or equal to 0.005 g/L; preferably, the raffinate organic phase obtained in step (4) is used in step (2) and/or step (3) after regeneration;

and/or the stripping stage number of the stripping treatment in the step (4) is 5-10 stages.

8. The method of claim 1, further comprising: carrying out extraction treatment on the first aqueous phase by applying the part of the nickel-loaded organic phase obtained in the step (3) as the first extracting agent in the step (2); preferably, BC196 is used for both the first extractant and the second extractant.

9. The method of claim 1, further comprising: subjecting the third aqueous phase to a pyrolysis spray treatment to obtain an impurity removal agent and/or a saponifier; and/or carrying out pyrolysis spraying treatment on the third water phase to obtain inorganic acid, and using the obtained inorganic acid for preparing laterite-nickel ore leaching liquid or washing the nickel-loaded organic phase in the step (4).

10. A method for extracting nickel from laterite-nickel ore is characterized by comprising the following steps: