A method for comprehensive recovery of nickel sulphide ore resources

Abstract

The application discloses a comprehensive recovery method of sulfide nickel ore resources, which comprises the following steps: step 1) pre-degslip talc flotation is carried out on a sulfide nickel ore slurry to obtain a talc rough concentrate and a talc flotation tailing; step 2) a sulfide nickel ore inhibitor is added into the talc rough concentrate to carry out talc nickel removal flotation, and a talc concentrate and a sulfide nickel middling are obtained; and step 3) the talc flotation tailing and the sulfide nickel middling are subjected to sulfide nickel flotation to obtain a sulfide nickel concentrate and a nickel flotation tailing. The comprehensive recovery method of the sulfide nickel ore resources provided by the application carries out talc flotation before the sulfide nickel flotation, removes talc, reduces the use of CMC, and avoids the negative influence of CMC on the flotation of the sulfide nickel ore. Moreover, the talc concentration is carried out by using the sulfide nickel ore inhibitor, the loss of the sulfide nickel ore in the talc is avoided, and the recovery rate of nickel is improved.

Description

Technical Field

[0001] This invention relates to the field of nickel sulfide ore resource recovery technology, specifically to a comprehensive method for recovering nickel sulfide ore resources. Background Technology

[0002] Nickel is an important non-ferrous metal raw material needed for the development of high technology and national economic construction, and is known as the "vitamin of industry." Based on geological origin, nickel deposits are mainly divided into two categories: magmatic sulfide nickel deposits and weathering laterite nickel deposits. Common metallic sulfides in nickel sulfide deposits include pyrrhotite, chalcopyrite, sulphite, pyrrhotite, and pyrite; metallic oxides include magnetite and limonite; and common gangue minerals include talc, serpentine, chlorite, olivine, and pyroxene.

[0003] Flotation is the primary method for separating nickel sulfide ores. During flotation, magnesium silicate minerals, especially talc, easily enter the flotation concentrate. Reducing the MgO content in the flotation concentrate has always been a challenging problem in mineral processing. Excessive magnesium gangue minerals entering the concentrate lower its grade and create difficulties for subsequent smelting processes. Currently, the commonly used method is to add gangue mineral depressants (including dispersants, complexing agents, and various combinations of reagents) to suppress talc and other minerals. The most commonly used talc depressant is CMC (sodium carboxymethyl cellulose). However, adding talc depressants such as CMC negatively impacts the flotation of minerals like pyrite, leading to a decrease in nickel recovery. Furthermore, some magnesium silicates such as talc contain small amounts of nickel, which is lost along with the talc in traditional beneficiation processes. Additionally, small amounts of pyrite and nickel-bearing pyrrhotite in the ore have poor floatability and are difficult to recover through flotation, further reducing nickel recovery. Moreover, small amounts of minerals such as magnetite in the ore are present in the flotation tailings. Due to the low content, the iron grade of the product obtained by magnetic separation of flotation tailings is low, and it is difficult to achieve more than 60%. In addition, the presence of pyrrhotite iron ore results in a high sulfur content in the magnetic concentrate, and this part of the magnetite cannot be effectively recovered in the existing process.

[0004] Therefore, there is a need to provide a comprehensive recovery method for nickel sulfide ore resources that does not use inhibitors such as CMC, to solve the problem that some nickel-bearing minerals and magnetite are difficult to recover and the nickel recovery rate is low in the existing flotation process, and to improve the overall recovery rate of valuable metals in the ore. Summary of the Invention

[0005] This invention employs a flotation pre-talc removal method to reduce talc content, eliminating the need for talc inhibitors such as CMC during nickel sulfide flotation and solving the technical problem of the negative impact of CMC on nickel sulfide flotation in existing technologies. Simultaneously, it combines flotation with reduction roasting-magnetic separation processes to comprehensively recover nickel pyrrhotite, pyrrhotite, magnetite, and nickel and iron resources from the flotation tailings, achieving comprehensive utilization of ore resources and improving the overall recovery rate of valuable metals in the ore. The technical solution adopted in this invention is as follows:

[0006] A comprehensive recovery method for nickel sulfide ore resources includes the following steps:

[0007] Step 1) Pre-flotation of nickel sulfide ore slurry to obtain talc rough concentrate and talc flotation tailings;

[0008] Step 2) Add nickel sulfide ore inhibitor to the talc rough concentrate and carry out nickel removal flotation of talc to obtain talc concentrate and nickel sulfide middlings;

[0009] Step 3) Combine the talc flotation tailings and nickel sulfide middlings and then perform nickel sulfide flotation to obtain nickel sulfide concentrate and nickel flotation tailings.

[0010] Optionally, in step 1), the proportion of nickel sulfide ore slurry with a grinding fineness of less than 0.074 mm is 70% to 80%.

[0011] Optionally, kerosene is used as the collector and No. 2 oil is used as the frother in the pre-detalting flotation.

[0012] Optionally, the amount of kerosene used is 10-20 g / t, and the amount of No. 2 oil used is 10-20 g / t.

[0013] Pre-removal of talc can avoid the use of large-molecule organic inhibitors such as carboxymethyl cellulose (CMC) in the nickel flotation stage, thus preventing a large amount of large-molecule organic matter from negatively impacting nickel sulfide flotation. However, since some sulfide ores have good floatability, they may enter the talc concentrate during talc flotation, causing loss of nickel sulfide. Therefore, nickel removal flotation with talc is necessary before nickel sulfide flotation.

[0014] Optionally, the nickel sulfide ore inhibitor in step 2) is a compound having the following chemical formula.

[0015]

[0016] Where X is a hydroxyl or amino group, and Me is a sodium or potassium ion.

[0017] Adding dithiocarbamates containing hydrophilic groups as desaturators for nickel sulfide ore in talc nickel removal flotation offers several advantages. Firstly, the desaturation effect on nickel pyrite is reversible; subsequent addition of xanthate directly restores its floatability.

[0018] Optionally, the nickel sulfide ore inhibitor is sodium aminoethyl dithiocarbamate or sodium hydroxyethyl dithiocarbamate.

[0019] Optionally, the amount of nickel sulfide inhibitor used is 80-150 g / t.

[0020] Optionally, xanthate collectors are used in the nickel sulfide flotation in step 3).

[0021] Optionally, the xanthate collector is selected from at least one of butyl xanthate, isopentyl xanthate, and pentyl xanthate.

[0022] Optionally, No. 2 oil is used as a frother in nickel sulfide flotation.

[0023] Optionally, gangue mineral inhibitors and activators are added during the nickel sulfide flotation process in step 3).

[0024] Optionally, the gangue mineral inhibitor is sodium hexametaphosphate;

[0025] Optionally, the activator is copper sulfate.

[0026] Optionally, the nickel flotation involves two stages of roughing, two stages of scavenging, and three stages of cleaning flotation. The roughing and scavenging stages use xanthate collectors at dosages of 55–65 g / t, 35–45 g / t, 15–25 g / t, and 5–15 g / t, respectively. Copper sulfate is added at 120–220 g / t during the first roughing stage. Sodium hexametaphosphate is added during the first and second cleaning stages, at dosages of 150–350 g / t and 80–160 g / t, respectively.

[0027] Optionally, the method further includes the following steps:

[0028] Step 4) Magnetic separation of nickel flotation tailings to obtain an aggregate of magnetic materials.

[0029] Optionally, the magnetic separation intensity is 2500 Oe to 5000 Oe.

[0030] Magnetic separation will yield magnetic minerals such as nickel-bearing pyrrhotite, pyrrhotite, and magnetite from the tailings, as well as intergrowths of pyrrhotite and pyrrhotite, and magnetite and pyrrhotite. Due to the presence of these intergrowths of pyrrhotite and magnetic minerals, pyrrhotite can be recovered from the flotation tailings through magnetic separation. The final magnetic separation product is an aggregate of magnetic materials containing iron and nickel, composed of the aforementioned minerals.

[0031] Optionally, the method further includes the following steps:

[0032] Step 5) The magnetic aggregate is mixed with the talc concentrate and then roasted at a temperature of 700-900℃ for 30-60 minutes.

[0033] Step 6) The roasting product from step 5) is subjected to a reduction reaction with a reducing agent to obtain a nickel-iron reduction product.

[0034] Roasting oxidizes nickel sulfide ore in magnetic separation products and talc concentrate, producing nickel-containing iron oxides. Analysis revealed that the iron oxides produced after oxidative roasting of pyrrhotite and nickel pyrrhotite exhibit higher reactivity and porosity due to phase reconstruction, making them easier to reduce to nickel-iron metal compared to traditional iron oxides. Furthermore, roasting causes dehydroxylation of talc minerals, loosening their layered structure and facilitating the diffusion of reducing gases during subsequent reduction roasting, thus promoting the reduction of nickel and iron within the minerals.

[0035] Optionally, the reducing agent is at least one of coal, natural gas, and hydrogen, and the reduction reaction temperature is 1100–1300°C, and the reaction time is 30–60 min.

[0036] Optionally, calcium fluoride is also added to the reduction reaction;

[0037] Optionally, the amount of calcium fluoride added is 5 to 15 wt% relative to the oxidative roasting product.

[0038] The oxides produced by sulfide oxidation roasting have higher reducing activity and can quickly generate metal nuclei. In the presence of calcium fluoride, they can further promote the growth of fine nickel-iron particles in talc.

[0039] Optionally, the method further includes crushing the nickel-iron reduction product and then magnetically separating it to obtain the nickel-iron product.

[0040] Optionally, the magnetic field strength for magnetic separation is 800–1500 Oe.

[0041] The technical solution of this invention has the following advantages:

[0042] 1. The comprehensive recovery method for nickel sulfide ore resources provided by this invention involves talc flotation before nickel sulfide flotation to remove talc, yielding talc rough concentrate and talc flotation tailings. Therefore, talc depressants such as CMC can be avoided in nickel sulfide flotation, thus preventing their negative impact on nickel sulfide ore flotation. Furthermore, the use of nickel sulfide ore depressants for talc fine cleaning of the talc rough concentrate, followed by return of the cleaned nickel sulfide ore to the sulfide flotation process, avoids the loss of nickel sulfide minerals during talc flotation and improves nickel recovery rate.

[0043] 2. The method of the present invention uses dithiocarbamate containing hydrophilic groups as a nickel sulfide ore inhibitor. This nickel sulfide ore inhibitor inhibits nickel sulfide ore while retaining the ability to restore the floatability of nickel sulfide ore, ensuring that it floats in subsequent nickel sulfide flotation.

[0044] 3. The comprehensive recovery method for nickel sulfide ore resources provided by the present invention adopts a combination of flotation and reduction roasting-magnetic separation processes to comprehensively recover nickel pyrrhotite, pyrrhotite, magnetite and nickel and iron resources in talc from nickel sulfide ore, thereby achieving comprehensive utilization of ore resources and improving the overall recovery rate of valuable metals in the ore. Attached Figure Description

[0045] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0046] Figure 1 This is a process flow diagram of an embodiment of the present invention. Detailed Implementation

[0047] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0048] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0049] The nickel recovery rate is calculated as follows: Nickel recovery rate = (Concentrate yield * Concentrate nickel grade) / Raw ore nickel grade.

[0050] The calculation method for magnetic iron recovery rate is: Iron recovery rate = (Concentrate yield * Concentrate iron grade) / Magnetic iron grade of raw ore.

[0051] Example 1

[0052] The nickel sulfide ore processed in this embodiment contains 0.65% nickel, with the main nickel-bearing minerals being pyrrhotite and nickel-bearing pyrrhotite, the main metal oxide being magnetite, and the main gangue minerals being pyroxene, serpentine, and talc. Talc flotation was carried out under the condition that the grinding fineness was -0.074 with 70% ore content, with kerosene dosage of 10 g / t and No. 2 oil dosage of 10 g / t.

[0053] Then, talc nickel removal flotation was carried out, using sodium aminoethyl dithiocarbamate as a nickel sulfide inhibitor at a dosage of 100 g / t, to obtain talc concentrate and nickel middlings.

[0054] Nickel middlings and talc flotation tailings were combined for nickel flotation, which consisted of two roughing stages, two scavenging stages, and three cleaning stages. The roughing and scavenging stages used butyl xanthate collectors at dosages of 60 g / t, 40 g / t, 20 g / t, and 10 g / t, respectively. Copper sulfate was added at 150 g / t in the first roughing stage. Sodium hexametaphosphate was added in the first and second cleaning stages at dosages of 200 g / t and 100 g / t, respectively.

[0055] In this embodiment, nickel concentrate with a nickel grade of 8.35% and a nickel recovery rate of 78.65% can be obtained by nickel flotation.

[0056] Nickel flotation tailings were subjected to magnetic separation at a magnetic field strength of 4000 Oe, yielding a magnetic aggregate. This magnetic aggregate was combined with the previously obtained talc concentrate and then subjected to oxidative roasting at 800℃ for 45 min. Subsequently, the roasted product was subjected to reduction roasting using coal as the reducing medium (20 wt% of the product), at 1200℃ for 45 min, with calcium fluoride added at 5 wt% of the product. The reduced product was then crushed, ground, and magnetically separated again at a magnetic field strength of 1500 Oe. The final product obtained was a nickel-iron product containing 2.3% nickel and 91.45% iron. Compared to the original ore, the nickel recovery rate was 8.12%, and the magnetic iron recovery rate was 85%.

[0057] The total recovery rate of nickel in nickel concentrate and ferronickel products reached 86.77%.

[0058] Comparative Example 1

[0059] Using the nickel sulfide ore from Example 1, without talc flotation and talc nickel removal flotation, nickel flotation was directly performed using the traditional CMC-suppressed talc process. The nickel flotation process was the same as in Example 1, using copper sulfate as the activator and butyl xanthate as the collector, employing a two-stage roughing, two-stage scavenging, and three-stage cleaning flotation. The dosages of butyl xanthate in the roughing and scavenging stages were 60 g / t, 40 g / t, 20 g / t, and 10 g / t, respectively; copper sulfate was added at 150 g / t in the first-stage roughing. CMC was added in the first-stage roughing, first-stage cleaning, and second-stage cleaning at dosages of 500 g / t, 150 g / t, and 100 g / t, respectively. Only a nickel sulfide concentrate with a nickel grade of 8.12% and a nickel recovery rate of 78% could be obtained.

[0060] Example 2

[0061] The nickel sulfide ore processed in this embodiment contains 0.72% nickel. The main nickel-bearing minerals are pyrrhotite and nickel-bearing pyrrhotite, the main metal oxide is magnetite, and the main gangue minerals are talc, serpentine, and chlorite. Talc flotation was carried out under the condition that the grinding fineness was -0.074 ohms (70%), and the kerosene dosage was 15 g / t, and the No. 2 oil dosage was 15 g / t.

[0062] Then, nickel removal flotation of talc was carried out, using sodium hydroxyethyl dithiocarbamate as a nickel sulfide inhibitor at a dosage of 120 g / t, to obtain talc concentrate and nickel middlings.

[0063] Nickel middlings and talc flotation tailings were combined for nickel flotation, which involved a two-stage roughing, two-stage scavenging, and three-stage cleaning flotation. The roughing and scavenging stages used butyl xanthate collectors at dosages of 60 g / t, 40 g / t, 20 g / t, and 10 g / t, respectively. Additionally, 200 g / t of copper sulfate was added to the first-stage roughing stage; sodium hexametaphosphate was added to the first and second-stage cleaning stages at dosages of 300 g / t and 150 g / t, respectively. The nickel flotation yielded a nickel concentrate with a nickel grade of 8.98% and a nickel recovery rate of 79.23%.

[0064] Nickel flotation tailings were subjected to magnetic separation at a magnetic field strength of 4500 Oe, yielding a magnetic aggregate. This magnetic aggregate was combined with the previously obtained talc concentrate and then subjected to oxidative roasting at 800℃ for 45 min. Subsequently, the roasted product was subjected to reduction roasting using coal as the reducing medium (20 wt% of the product), at 1200℃ for 45 min, with calcium fluoride added at 10 wt%. The reduced product was then crushed, ground, and magnetically separated at a magnetic field strength of 1500 Oe, ultimately yielding a nickel-iron product containing 2.6% nickel and 91.79% iron. Compared to the original ore, the nickel recovery rate was 8.87%, and the magnetic iron recovery rate was 86%.

[0065] The total nickel recovery rate in nickel concentrate and ferronickel products reached 88.10%.

[0066] Comparative Example 2

[0067] Using the nickel sulfide ore from Example 1, without talc flotation and talc nickel removal flotation, nickel flotation was directly performed using the traditional CMC-suppressed talc process. The nickel flotation process was the same as in Example 1: copper sulfate was used as the activator, butyl xanthate as the collector, and a two-stage roughing, two-stage scavenging, and three-stage cleaning flotation were employed. The dosages of butyl xanthate in the roughing and scavenging stages were 60 g / t, 40 g / t, 20 g / t, and 10 g / t, respectively. Additionally, 200 g / t of copper sulfate was added in the first-stage roughing; and CMC was added in the first-stage roughing, first-stage cleaning, and second-stage cleaning at dosages of 600 g / t, 200 g / t, and 100 g / t, respectively. Only a nickel sulfide concentrate with a nickel grade of 8.45% and a nickel recovery rate of 78.56% could be obtained.

[0068] As can be seen from the above embodiments and comparative examples, the method of the present invention can not only improve the grade and recovery rate of nickel sulfide concentrate in the flotation stage, but also achieve comprehensive resource recovery of nickel sulfide in talc and tailings, as well as nickel and iron in magnetite.

[0069] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for comprehensive recovery of nickel sulfide ore resources, characterized in that, Includes the following steps: Step 1) Pre-flotation of nickel sulfide ore slurry to obtain talc rough concentrate and talc flotation tailings; Step 2) Add a nickel sulfide ore inhibitor to the talc rough concentrate and perform nickel removal flotation of talc to obtain talc concentrate and nickel sulfide middlings; the nickel sulfide ore inhibitor in step 2) is a compound having the following chemical formula Where X is a hydroxyl or amino group, and Me is a sodium or potassium ion; Step 3) The talc flotation tailings and nickel sulfide middlings are subjected to nickel sulfide flotation to obtain nickel sulfide concentrate and nickel flotation tailings.

2. The method for comprehensive recovery of nickel sulfide ore resources according to claim 1, characterized in that, In step 1), the proportion of nickel sulfide ore slurry with a grinding fineness of less than 0.074 mm is 70%~80%.

3. The method for comprehensive recovery of nickel sulfide ore resources according to claim 1, characterized in that, In step 3), xanthate collectors are used for nickel sulfide flotation.

4. The method for comprehensive recovery of nickel sulfide ore resources according to claim 1, characterized in that, In step 3), gangue mineral inhibitors and activators are added during the nickel sulfide flotation process.

5. The method for comprehensive recovery of nickel sulfide ore resources according to any one of claims 1 to 4, characterized in that, The method further includes the following steps: Step 4) Perform magnetic separation on the nickel flotation tailings to obtain an aggregate of magnetic materials.

6. The method for comprehensive recovery of nickel sulfide ore resources according to claim 5, characterized in that, The method further includes the following steps: Step 5) Mix the magnetic material aggregate with the talc concentrate and then roast it at a temperature of 700~900℃ for 30~60min. Step 6) The roasting product from step 5) is subjected to a reduction reaction with a reducing agent to obtain a nickel-iron reduction product.

7. The method for comprehensive recovery of nickel sulfide ore resources according to claim 6, characterized in that, The reducing agent is at least one of coal, natural gas, and hydrogen, and the reduction reaction temperature is 1100~1300℃, and the reaction time is 30~60min.

8. The method for comprehensive recovery of nickel sulfide ore resources according to claim 6, characterized in that, Calcium fluoride was also added to the reduction reaction.

9. The method for comprehensive recovery of nickel sulfide ore resources according to any one of claims 6 to 8, characterized in that, The method also includes crushing the nickel-iron reduction product and then magnetically separating it to obtain the nickel-iron product.

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