CN114015871A

CN114015871A - Method for leaching nickel sulfide concentrate under mild pressure selectively

Info

Publication number: CN114015871A
Application number: CN202210007900.3A
Authority: CN
Inventors: 王海北; 谢铿; 杨必文; 王玉芳; 刘三平; 王德卿
Original assignee: BGRIMM Technology Group Co Ltd
Current assignee: BGRIMM Technology Group Co Ltd
Priority date: 2022-01-06
Filing date: 2022-01-06
Publication date: 2022-02-08
Anticipated expiration: 2042-01-06
Also published as: CN114015871B

Abstract

The application provides a method for leaching nickel sulfide concentrate under mild pressure selectively, and relates to the field of metallurgy. The mild pressure selective leaching method of nickel sulfide concentrate includes: grinding the nickel sulfide concentrate to obtain ore pulp, mixing the ore pulp with a dispersing agent and sulfuric acid to obtain a mixture, carrying out oxygen pressure leaching, and carrying out solid-liquid separation to obtain a leaching solution and leaching residues; the temperature of the oxygen pressure leaching is 120-150 ℃, and the oxygen partial pressure is 0.1-0.8 MPa. According to the method for the mild pressure selective leaching of the nickel sulfide concentrate, the nickel sulfide concentrate is leached under mild conditions through low temperature and low oxygen partial pressure, the leaching rate of nickel and cobalt is more than 95%, the leaching rate of iron is less than 15%, and the leaching rate of copper is less than 40%; can control the little oxidation of the pyrite and the chalcopyrite; low equipment requirement, high safety and low cost.

Description

Method for leaching nickel sulfide concentrate under mild pressure selectively

Technical Field

The application relates to the field of metallurgy, in particular to a method for leaching nickel sulfide concentrate under mild pressure selectively.

Background

The nickel sulfide concentrate contains a part of pyrrhotite and pyrite, as well as a small amount of chalcopyrite and cobalt sulfide, in addition to pentlandite. The method is used for recovering nickel, cobalt and copper by using a pyrogenic method and a wet method. Smelting and matte making are carried out in a pyrometallurgy process, high nickel matte is obtained after blowing, slagging and refining, and nickel and copper are separated after flotation; the method has the problems of long process flow, high smelting temperature, large loss of valuable metals, low cobalt recovery rate and the like. Common wet treatment comprises a normal pressure-air pressure leaching mode and a high oxygen-high temperature pressure leaching mode, wherein the normal pressure-air pressure leaching mode can leach nickel and cobalt, copper is remained in slag, the nickel and cobalt leaching rate is low, the leaching time is long, and the iron content in a leaching solution is high; the latter has high leaching rate of nickel and cobalt, iron can be effectively remained in the slag, but most of copper is in the leaching solution, which is not beneficial to the separation of nickel and cobalt, and the reaction temperature is high, the pressure is large, and the requirement on equipment is high.

Disclosure of Invention

The application aims to provide a method for the mild pressure selective leaching of nickel sulfide concentrate, so as to solve the problems.

In order to achieve the purpose, the following technical scheme is adopted in the application:

a method for the mild pressure selective leaching of nickel sulfide concentrate comprises the following steps:

grinding the nickel sulfide concentrate to obtain ore pulp, mixing the ore pulp with a dispersing agent and sulfuric acid to obtain a mixture, carrying out oxygen pressure leaching, and carrying out solid-liquid separation to obtain a leaching solution and leaching residues;

the temperature of the oxygen pressure leaching is 120-150 ℃, and the oxygen partial pressure is 0.1-0.8 MPa.

Preferably, the oxygen pressure leaching time is 1-5 h.

Preferably, the proportion of the particle size of the ore in the ore pulp is less than or equal to 75 mu m and not less than 70 percent.

Preferably, the sulfuric acid is concentrated sulfuric acid, and the addition amount of the concentrated sulfuric acid is 5% -12% of the weight of the nickel sulfide concentrate.

Preferably, in the oxygen pressure leaching process, the reaction vessel is vented.

Preferably, the dispersant comprises sodium lignosulfonate.

Preferably, the addition amount of the dispersing agent is 0.5-3% of the weight of the nickel sulfide concentrate.

Preferably, the liquid-solid ratio of the mixture is (3-10): 1.

preferably, the nickel sulfide concentrate comprises, by mass:

4-7% of chalcopyrite, 15-30% of pentlandite, 25-40% of pyrrhotite, 15-25% of pyrite and 5-15% of gangue.

Preferably, the leached slag is washed by water, floated and separated to obtain copper and iron.

Compared with the prior art, the beneficial effect of this application includes:

according to the method for the mild pressure selective leaching of the nickel sulfide concentrate, the ore pulp, the dispersing agent and the sulfuric acid are mixed for oxygen pressure leaching, the technological condition opposite to the conventional high-temperature high-pressure reaction idea is selected, the oxidation of the pyrite and the chalcopyrite is reduced under the conditions of low temperature and low oxygen partial pressure, the nickel and cobalt leaching rate is more than 95%, the iron leaching rate is less than 15% and the copper leaching rate is less than 40%, so that the nickel and cobalt are effectively separated from the iron and copper, and the valuable metals are more effectively obtained and utilized.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments are briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope of the present application.

Fig. 1 is a process flow diagram of a method for the mild pressure selective leaching of nickel sulfide concentrate provided in example 1.

Detailed Description

The terms as used herein:

"prepared from … …" is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of … …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of … …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when the range "1 ~ 5" is disclosed, the ranges described should be construed to include the ranges "1 ~ 4", "1 ~ 3", "1 ~ 2 and 4 ~ 5", "1 ~ 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In these examples, the parts and percentages are by mass unless otherwise indicated.

"part by mass" means a basic unit of measure indicating a mass ratio of a plurality of components, and 1 part may represent any unit mass, for example, 1g or 2.689 g. If we say that the part by mass of the component A is a part by mass and the part by mass of the component B is B part by mass, the ratio of the part by mass of the component A to the part by mass of the component B is a: b. alternatively, the mass of the A component is aK and the mass of the B component is bK (K is an arbitrary number, and represents a multiple factor). It is unmistakable that, unlike the parts by mass, the sum of the parts by mass of all the components is not limited to 100 parts.

"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).

In general, it is believed that in hydrometallurgy, the high-temperature, high-pressure and high-acid conditions are favorable for metal leaching and separation, so the prior art generally adopts a high-temperature, high-pressure and large-amount acid liquid treatment mode to leach complex nickel sulfide concentrate. However, the inventor of the application finds that due to the particularity of the components of the complex nickel sulfide concentrate, under the conventional high-temperature high-pressure high-acid condition, pyrite is seriously oxidized, a large amount of iron is leached along with nickel and cobalt, the separation of nickel and cobalt is not facilitated, the subsequent iron removal and pressure bearing are huge, and the high-temperature high-pressure high-acid condition has high requirements on equipment, high energy consumption, high reagent consumption, high investment cost and operation cost and poor safety performance. Therefore, based on the research on the components of the complex nickel sulfide concentrate and the discovery of the phenomena, the existing high-temperature high-pressure high-acid condition leaching is abandoned, the relatively mild leaching method is adopted, the leaching selectivity is promoted, the leaching of iron is inhibited while nickel and cobalt are leached to the maximum extent, and the effective separation of nickel and cobalt and iron is realized.

Optionally, the oxygen pressure leaching temperature may be any value between 120 ℃, 130 ℃, 140 ℃, 150 ℃ or between 120 ℃ and 150 ℃, and the oxygen partial pressure may be any value between 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa or between 0.1MPa and 0.8 MPa.

In an alternative embodiment, the oxygen pressure leaching is performed for a period of time in the range of 1h to 5 h.

Optionally, the time of the oxygen pressure leaching may be 1h, 2h, 3h, 4h, 5h or any value between 1h and 5 h.

In an alternative embodiment, the proportion of ore in the pulp having a particle size of 75 μm or less is not less than 70%.

Optionally, the proportion of the ore particle size of 75 μm or less in the ore slurry may be 70%, 75%, 80%, 85%, 90%, 95%, 100% or any value not lower than 70%.

In an optional embodiment, the sulfuric acid is concentrated sulfuric acid, and the addition amount of the concentrated sulfuric acid is 5% -12% of the weight of the nickel sulfide concentrate.

In an alternative embodiment, the reaction vessel is vented during the oxygen pressure leaching.

In general, in the case of a high oxygen partial pressure, since the strength of the introduced oxygen gas is high and a high dissolved oxygen concentration can be obtained, attention is not paid to the degassing operation of the vessel, and the influence of the degassing operation on the leaching result is not found. However, the application finds that under the condition of low oxygen partial pressure, the complex nickel sulfide concentrate can generate some side reactions, partial gas substances are generated, and water vapor occupies the gas space in the kettle.

In an alternative embodiment, the dispersant comprises sodium lignosulfonate.

In an alternative embodiment, the dispersant is added in an amount of 0.5% to 3% by weight of the nickel sulphide concentrate.

Optionally, the dispersant may be added in an amount of 0.5%, 1%, 1.5%, 2%, 2.5%, 3% or any value between 0.5% and 3% by weight of the nickel sulphide concentrate.

In an alternative embodiment, the liquid-to-solid ratio of the mix is (3-10): 1.

optionally, the liquid-solid ratio of the mixture may be 3: 1. 4: 1. 5: 1. 6: 1. 7: 1. 8: 1. 9: 1. 10: 1 or (3-10): 1, or any value between.

In an alternative embodiment, the nickel sulfide concentrate, in mass percent, comprises:

Alternatively, the content of chalcopyrite in the nickel sulphide concentrate may be any value between 4%, 5%, 6%, 7% or 4% and 7%, the content of pentlandite may be any value between 15%, 20%, 25%, 30% or 15% and 30%, the content of pyrrhotite may be any value between 25%, 30%, 35%, 40% or 25% and 40%, the content of pyrite may be any value between 15%, 20%, 25% or 15% and 25%, and the content of gangue may be any value between 5%, 10%, 15% or 5% and 15%.

In an alternative embodiment, the leached slag is washed by water, floated and separated to obtain copper and iron.

Embodiments of the present application will be described in detail below with reference to specific examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present application and should not be construed as limiting the scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The nickel sulfide concentrate used in the application comprises the following main components: 4-7% of chalcopyrite, 15-30% of pentlandite, 25-40% of pyrrhotite, 15-25% of pyrite and 5-15% of gangue.

Example 1

As shown in fig. 1, this embodiment provides a method for the mild pressure selective leaching of nickel sulfide concentrate, which includes the following steps:

50 g of nickel sulfide concentrate (containing 1 percent of other minerals) with the main components of 7 percent of chalcopyrite, 15 percent of pentlandite, 40 percent of pyrrhotite, 25 percent of pyrite and 12 percent of gangue is ground and added with 500 mL of water to prepare ore pulp, and the granularity of 90 percent is less than 75 mu m. 1g of sodium lignosulphonate and 4.4 g of 98% concentrated sulfuric acid are added into the ground ore pulp, and the mixture is stirred to obtain mixed pulp. And (3) putting the uniformly mixed slurry into a pressure kettle, introducing oxygen, discharging redundant air, controlling the reaction temperature to be 140 ℃, the oxygen partial pressure to be 0.2 +/-0.05 MPa, and leaching for 3 hours. After leaching, the leaching rate of nickel is 95.20%, the leaching rate of cobalt is 95.11%, the leaching rate of copper is 38.87%, and the leaching rate of iron is 8.95%.

After the leached slag is cleaned and filtered, copper concentrate and iron slag are obtained through flotation and separation, and further effective utilization of copper and iron resources is realized.

Example 2

The embodiment provides a method for the mild pressure selective leaching of nickel sulfide concentrate, which comprises the following specific steps:

100 g of nickel sulfide concentrate (containing 1 percent of other minerals) with the main components of 6 percent of chalcopyrite, 15 percent of pentlandite, 40 percent of pyrrhotite, 25 percent of pyrite and 13 percent of gangue is ground and added with 400 mL of water to prepare ore pulp, and the granularity of 90 percent is less than 75 mu m. 1.5 g of sodium lignosulphonate and 9g of 98% concentrated sulfuric acid are added into the ground ore pulp, and the mixture is stirred to obtain mixed pulp. And (3) putting the uniformly mixed slurry into a pressure kettle, introducing oxygen, discharging redundant air, controlling the reaction temperature to be 140 ℃, the oxygen partial pressure to be 0.2 +/-0.05 MPa, and leaching for 2 hours. After leaching, the leaching rate of nickel is 95.07 percent, the leaching rate of cobalt is 95.05 percent, the leaching rate of copper is 38.84 percent, and the leaching rate of iron is 7.79 percent.

Example 3

200 g of nickel sulfide concentrate (containing 1% of other minerals) with main components of chalcopyrite 4%, pentlandite 29%, pyrrhotite 32%, pyrite 21% and gangue 13% is taken, 1000 mL of water is added, and ore pulp is obtained after ore grinding, wherein 86% of the particle size is smaller than 75 microns. 3.5 g of sodium lignosulphonate and 10 g of 98% concentrated sulfuric acid are added into the ground ore pulp, and the mixture is stirred to obtain mixed pulp. And (3) putting the uniformly mixed slurry into a pressure kettle, introducing oxygen, discharging redundant air, controlling the reaction temperature to be 135 ℃, the oxygen partial pressure to be 0.2 +/-0.05 MPa, and leaching for 4 hours. After leaching, the leaching rate of nickel is 95.05%, the leaching rate of cobalt is 95.14%, the leaching rate of copper is 29.54%, and the leaching rate of iron is 13.87%.

Example 4

taking 50 g (containing 1% of other minerals) of nickel sulfide concentrate with the main components of 7% of chalcopyrite, 15% of pentlandite, 40% of pyrrhotite, 25% of pyrite and 12% of gangue, grinding, adding 300 mL of water to prepare ore pulp, wherein 88% of the ore pulp has the particle size of less than 75 μm. 1.5 g of sodium lignosulphonate and 8 g of 98% concentrated sulfuric acid are added into the ground ore pulp, and the mixture is stirred to obtain mixed pulp. And (3) putting the uniformly mixed slurry into a pressure kettle, introducing oxygen, discharging redundant air, controlling the reaction temperature to be 130 ℃, the oxygen partial pressure to be 0.6 +/-0.05 MPa, and leaching for 3 hours. After leaching, the leaching rate of nickel is 95.01%, the leaching rate of cobalt is 95.17%, the leaching rate of copper is 23.44%, and the leaching rate of iron is 9.65%.

Comparative example 1

The comparative example provides a method for leaching nickel sulfide concentrate, which comprises the following specific steps:

taking 50 g of a nickel sulfide concentrate which mainly comprises 7% of chalcopyrite, 15% of pentlandite, 40% of pyrrhotite, 25% of pyrite and 12% of gangue, grinding, and adding 500 mL of water to prepare ore pulp, wherein 90% of the ore pulp has the particle size smaller than 75 mu m. Adding 1g of sodium lignosulphonate and 10 g of 98% concentrated sulfuric acid into the ground ore pulp, and stirring to obtain mixed pulp. And (3) putting the uniformly mixed slurry into a pressure kettle, introducing oxygen, controlling the reaction temperature to be 180 ℃, the oxygen partial pressure to be 0.8 +/-0.05 MPa, and leaching for 3 hours. After leaching, the leaching rate of nickel is 94.83%, the leaching rate of cobalt is 95.14%, the leaching rate of copper is 93.55%, and the leaching rate of iron is 60.31%.

From the results of comparative example 1, it is understood that the leaching rate of nickel and cobalt is not greatly changed without performing the degassing operation during the leaching process, but the leaching rate of copper and iron is greatly increased.

Comparative example 2

Taking 200 g of nickel sulfide concentrate which mainly comprises 7% of chalcopyrite, 15% of pentlandite, 40% of pyrrhotite, 25% of pyrite and 12% of gangue, adding 1000 mL of water, and grinding to obtain ore pulp, wherein 86% of the ore pulp has the particle size smaller than 75 microns. 3.5 g of sodium lignosulphonate and 40 g of 98% concentrated sulfuric acid are added into the ground ore pulp, and the mixture is stirred to obtain mixed pulp. And (3) putting the uniformly mixed slurry into a pressure kettle, introducing oxygen, controlling the reaction temperature to be 200 ℃, the oxygen partial pressure to be 0.6 +/-0.05 MPa, and the leaching time to be 4 h. After leaching, the leaching rate of nickel is 96.29%, the leaching rate of cobalt is 95.46%, the leaching rate of copper is 90.92%, and the leaching rate of iron is 62.65%.

From the results of comparative example 2, it is understood that under the condition of higher temperature, and the exhaust operation is not performed in the leaching process, the leaching rate of nickel and cobalt is improved, but the leaching rate of copper and iron is greatly improved.

The method provided by the application can effectively separate nickel, cobalt and copper and iron, and is short in process flow, wherein the nickel and cobalt leaching rate is more than 95%, the iron leaching rate is less than 15%, and the copper leaching rate is less than 40%; can control the little oxidation of the pyrite and the chalcopyrite. The method adopts a mild pressure leaching mode, and the leaching temperature is low and does not exceed 150 ℃; the using amount of the sulfuric acid is less and is not more than 12 percent of the nickel concentrate; the oxygen partial pressure is not high and is only maintained between 0.1 and 0.8 MPa. The leaching slag can effectively separate copper and iron after washing and flotation, and the recycling of the copper and the iron is promoted.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Moreover, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the application and form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Claims

1. A method for the mild pressure selective leaching of nickel sulfide concentrate is characterized by comprising the following steps:

2. The method of claim 1, wherein the oxygen pressure leaching is performed for a period of time ranging from 1 hour to 5 hours.

3. The method according to claim 1, characterized in that the proportion of the ore in the pulp with a particle size of 75 μm or less is not lower than 70%.

4. The method of claim 1, wherein the sulfuric acid is concentrated sulfuric acid, and the concentrated sulfuric acid is added in an amount of 5-12% by weight of the nickel sulfide concentrate.

5. The method of claim 1, wherein during the oxygen pressure leaching, the reaction vessel is vented.

6. The method of claim 1, wherein the dispersant comprises sodium lignosulfonate.

7. The method of claim 6, wherein the dispersant is added in an amount of 0.5% to 3% by weight of the nickel sulfide concentrate.

8. The method of claim 1, wherein the liquid-to-solid ratio of the mix is (3-10): 1.

9. the method of claim 1, wherein the nickel sulfide concentrate comprises, in mass percent:

10. The method according to any one of claims 1 to 9, characterized in that the leached slag is washed with water, floated and separated to obtain copper and iron.