A method for extracting iron concentrate from laterite nickel ore hydrometallurgical slag
The use of biochar as a reducing agent, optimized through heating and activation processes, addresses inefficiencies in iron recovery from laterite nickel ore hydrometallurgical slag, achieving high purity and low environmental impact, providing a sustainable and cost-effective solution.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-10-04
- Publication Date
- 2026-04-02
AI Technical Summary
The existing methods for recovering iron from laterite nickel ore hydrometallurgical slag are inefficient, environmentally harmful, and costly, primarily due to the use of non-renewable reducing agents like coal and coke, and the complex chemical composition of the slag leads to low recovery efficiency.
A method using biochar as a reducing agent, optimized through specific heating and activation processes, combined with magnetic separation and additives, to enhance iron recovery from laterite nickel ore hydrometallurgical slag.
The method achieves efficient iron recovery with high purity and low environmental impact, utilizing biochar's high surface area and pore structure, and reduces energy consumption, offering a cost-effective and sustainable alternative to traditional reducing agents.
Smart Images
Figure ID2024000023_02042026_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] A METHOD FOR EXTRACTING IRON CONCENTRATE FROM LATERITE NICKEL ORE HYDROMETALLURGICAL SLAG
[0003] Technical Field
[0004] The application belongs to the technical field of slag recovery and utili zation, and speci fically relates to a method for extracting iron concentrate from the hydrometallurgical slag of laterite nickel ore .
[0005] Background
[0006] Nickel is a kind of strategic reserve metal . It is widely used and plays an important role in the social economy . Nickel is the main material for the preparation of new energy batteries . With the rapid development of new energy industry, the demand for nickel resources is also rising .
[0007] With the large consumption of nickel sul fide ore resources , nickel sul fide ore resources gradually began to be exhausted, the international began to nickel resources development target to laterite nickel resources . At present , the treatment of laterite nickel ore is mainly based on hydrometallurgical process , which can have better treatment ef fect for low grade ore . However, a large amount of slag will be produced in the hydrometallurgical process of laterite nickel ore . At present , the treatment of metallurgical slag mainly adopts tailings dam accumulation, underground pressure filtration backfill and deep sea landfill , which has problems such as high treatment cost , environmental pollution and resource waste . The chemical composition of laterite nickel ore hydrometallurgical slag is complex, but its iron content is more than 40% . Therefore , the recovery and utili zation of iron resources from the hydrometallurgical slag of laterite nickel ore is an ef fective solution .
[0008] At present , iron concentrate is mainly recovered from the hydrometallurgical slag of laterite nickel ore by reduction roasting and magnetic separation process . Speci fically, reducing agent is added to the hydrometallurgical slag and roasting under high temperature environment , and then iron concentrate is separated by magnetic separation . At present , coal , coke and natural gas are mostly used as reducing agents for the recovery and utili zation of laterite nickel ore hydrometallurgical slag . However, according to the principle of reduction roasting, the reducing agent can also use other carbon substances . Compared with non-renewable petrochemical resources such as coal and coke , biochar has the characteristics of wide distribution, low price and ecological protection, so it is of great signi ficance to use biochar to recover iron concentrate from laterite nickel ore hydrometallurgical slag . However, the existing research shows that the reducing agent is the key factor that determines the roasting ef fect and then af fects the iron recovery ef ficiency, and the inventor ' s previous research shows that the preparation condition of biochar is very important to the iron recovery ef ficiency .
[0009] Summary
[0010] In view of this , this application aims to provide a method for extracting iron concentrate from the hydrometallurgical slag of laterite nickel ore , which uses biochar as reducing agent and improves roasting and magnetic separation operations under biochar conditions to achieve ef ficient recovery of iron .
[0011] The technical scheme of this application is as follows :
[0012] A method for extracting iron concentrate from the hydrometallurgical slag of laterite nickel ore includes the following steps :
[0013] 51 . The biomass was heated to 350- 600°C under nitrogen atmosphere for 80- 160 min, naturally cooled, and then heated to 350- 600°C under carbon dioxide atmosphere for 40-70 min, naturally cooled, grated and sieved to obtain the biomass charcoal ;
[0014] 52 . The laterite nickel hydrometallurgical slag, biochar and additives are mixed and reduced and roasting to obtain the roasting product ;
[0015] S3 . Add dispersants to the roasting products , add water after ball milling to obtain intermediate slurry, and dry after magnetic separation to obtain iron concentrate.
[0016] Preferably, in the above method, step SI includes the following processes :
[0017] 511. The biomass is initially broken, washed with water to remove impurities, and dried at 90-100 °C for 400-520 min, in which the biomass is one or more of coconut husks, wheat stalks, corn stalks, bamboo, rice stalks, peanut shells and branches (such as various fruit tree branches ) ;
[0018] 512. In the nitrogen atmosphere, with the heating rate of l-5°C / min heating to 350-600°C treatment 80-160 min, natural cooling to room temperature (15-35°C) ;
[0019] 513. In the carbon dioxide atmosphere, with the heating rate of
[0020] 1-5°C / min heating to 350-600°C activation treatment 40-70 min, natural cooling to room temperature;
[0021] 514. After grinding through 40-300 mesh sieve, wash with water to remove impurities, and then dry at 110-120°C for 680-800 min, to obtain biochar.
[0022] Preferably, in the above method, the amount of biochar added is
[0023] 2-5 wt% of the mass of laterite nickel ore hydrometallurgical slag.
[0024] Preferably, in the above methods, the additives are Na2COs and / or NaOH;
[0025] Preferably, the amount of additive is 4-6 wt% of the mass of laterite nickel ore hydrometallurgical slag.
[0026] Preferably, in the above method, the mixing is carried out by ball milling in step S2;
[0027] Preferably, the ball milling time is 30-120 min.
[0028] Preferably, in the above method, the temperature is heated at 3-6 °C / min to 500-900 °C for reduction roasting for 30-180 min under argon atmosphere .
[0029] Preferably, argon is introduced at a rate of 1-5 mL / min. Preferably, in the above method, step S2 uses one or more dispersants of sodium metaphosphorate, sodium hexametaphosphorate, sodium silicate, caustic starch, salinized sodium silicate (that is, a mixture of sodium silicate and aluminum sulfate) , and the amount of dispersant is 3-5 wt% of the mass of the roasted product.
[0030] Preferably, in the above method, in step S3, 4-6 times the mass of solid material water is added for slurry mixing, thus obtaining the intermediate slurry. Preferably, in the above method, the strength of magnetic separation is 1000-3000 Gs .
[0031] Compared with the existing technology, the beneficial ef fects of the application are as follows :
[0032] The chemical composition of laterite nickel ore hydrometallurgical slag is more complex, containing a variety of mineral types and a high content of harmful impurity S . The application aims at the extraction of iron concentrate from the hydrometallurgical slag of laterite nickel ore , and the preparation process of biochar is optimi zed in applicability . The calorical value of the biochar produced is equivalent to that of the commercial carbon source , and has the advantages of stable performance , low sul fur content , and no heavy metals . More importantly, compared with other carbon sources ( such as coke , coal , etc . ) , the biochar provided in this application has comparable or even better iron recovery ef fect .
[0033] In the preparation process o f the biochar in this application, through the carboni zation process under nitrogen atmosphere , the organic components of the biomass are trans formed into inorganic carbon after high temperature treatment ; Then, the pore structure was regulated and improved by carbon dioxide activation treatment , which was conducive to further improving the iron recovery ef fect . The application uses carbon dioxide as the activator, the process is relatively simple , the waste gas generated is mainly CO2 and water vapor, and the environmental pollution is small . Moreover, the final biochar product has high speci fic surface area, developed pore structure , and wide application range .
[0034] By adding Na2COs and / or NaOH as additives in the roasting process , this application can reduce the melting point , save energy consumption, and is conducive to the react ion of some substances in the slag to generate sul f ide , which is easy to be removed by the subsequent magnetic separation process , and finally further improve the purity of the iron concentrate . At the same time , the inventor found that the use of argon as the inert gas was more beneficial to improve the purity of the iron concentrate than nitrogen .
[0035] Based on the biochar in this application as a reducing agent, this application provides a certain carbon source and reduces the baking temperature in the process of roasting by mixing a certain amount of Na^COs and / or NaOH as an additive , combined with argon atmosphere , which can ef fectively ensure the iron recovery ef fect . In addition, the addition of dispersants in the magnetic separation step can ef fectively ensure that the particulate matter is evenly dispersed in the liquid medium and prevent its precipitation and condensation .
[0036] This application applies biochar for the first time in the reduction roasting of laterite nickel ore hydrometallurgical slag to recover iron, and its recovery ef fect is equivalent or even better than that of coal or other reducing agents ( such as coke ) prepared from coal as raw material . Moreover, biochar is more environmentally friendly, less expensive and more cost-ef fective .
[0037] The application method can recover iron concentrate products from laterite nickel ore hydrometallurgical slag, and the obtained non-magnetic substances can be used to produce building materials or cement products , improve the resource utili zation rate and economic benefits of laterite nickel ore , and play a positive role in solving the environmental problems caused by long-term storage and landfill of laterite nickel ore hydrometallurgical slag .
[0038] Brief Description Of The Drawings
[0039] Figure 1 shows the process flow chart of the extraction method of iron concentrate from the hydrometallurgical slag of laterite nickel ore provided in this application .
[0040] Detailed Description
[0041] Unless otherwise defined, all technical and scienti fic terms used herein have the same meaning as would normally be understood by a person skilled in the field of technology belonging to this application . The term " including" in the description of this application and in the claims , and any variation thereof , is intended to cover non-exclusive inclusion .
[0042] In view of the resource utili zation of laterite nickel ore hydrometallurgical slag, this application expects to use biochar to replace the existing reducing agents such as coal and coke , and explore a more environmentally friendly resource way of laterite nickel ore hydrometallurgical slag . Speci fically, as shown in Figure 1 , this application provides a method for extracting iron concentrate from laterite nickel hydrometallurgical slag, including the following steps :
[0043] ( 1 ) Preparation of biochar : the biomass is heated to 350- 600 °C under nitrogen atmosphere for 80- 160 min, naturally cooled, and then heated to 350- 600 °C under carbon dioxide atmosphere for 40-70 min, naturally cooled, grated and screened to obtain biochar ;
[0044] ( 2 ) Reduction roasting : the laterite nickel hydrometallurgical slag, biochar and additives are mixed, and the roasting product is obtained by reduction roasting under a certain atmosphere ;
[0045] ( 3 ) Magnetic separation : adding dispersants to the roaster products and ball milling treatment , adding water to prepare the intermediate slurry, magnetic separation of the intermediate slurry under a speci fic magnetic separation intensity, filtering and drying treatment to obtain magnetic and non-magnetic substances .
[0046] Based on the characteristics of laterite nickel ore hydrometallurgical slag, this application uses biomass raw materials and successively undergoes high temperature treatment under nitrogen atmosphere and carbon dioxide atmosphere to obtain biochar that can ef fectively reduce iron in laterite nickel ore hydrometallurgical slag . Based on biochar, The reduction rostering conditions ( such as additives and their types , heating conditions , reaction atmosphere , etc . ) and magnetic separation conditions ( such as dispersants and magnetic separation strength) were improved, so as to reali ze the purpose of replacing conventional reducing agents by biochar, and the recovery ef fect of this program has industrial value .
[0047] In the following, the technical scheme of this application will be clearly and completely described in combination with speci fic examples . It should be understood that the embodiments described herein are for the purpose of illustrating and interpreting the Application and are not intended to limit the Application .
[0048] The following examples and the composition of the laterite nickel ore hydrometallurgical slag (with sul furic acid as the leaching medium) used in the proportion are shown in Table 1 .
[0049] Table 1 Analysis of main components of hydrometallurgical slag of laterite nickel ore
[0050] Where no speci fic technology or conditions are indicated in the following embodiments , the technology or conditions described in the literature in the field or in the product speci fication are used; I f the manufacturer is not indicated, the reagents or instruments used are conventional products that can be obtained through market purchase .
[0051] Embodiment 1
[0052] A method for extracting iron concentrate from laterite nickel ore hydrometallurgical slag includes the following steps :
[0053] ( 1 ) Preparation of biochar .
[0054] Coconut shell was used as biomass raw material to prepare biochar through the following processes :
[0055] (T) The coconut shell was broken to less than 3 cm, the surface impurities were removed by deioni zed water, and then dried at 100°C for 480 min;
[0056] @ Under nitrogen atmosphere , the temperature was heated to 500°C at a heating rate of 5°C / min for 120 min, and then natural ly cooled to room temperature ;
[0057] @ Under carbon dioxide atmosphere , the temperature was heated to 450°C at a heating rate of 5°C / min for 60 min, and then naturally cooled to room temperature ;
[0058] (?) It was crushed with a ball mill , passed through a 200 mesh screen, washed with deioni zed water for 3 times to remove impurities , and then dried at 120 °C for 720 min to obtain biochar .
[0059] ( 2 ) Reduction roasting .
[0060] The laterite nickel ore hydrometallurgical slag, 3 wt% biochar and 5 wt% Na2COs were ball milled uni formly in a ball mill for 70 min . The material obtained after ball milling was placed in the atmosphere furnace , and the argon flow rate of 3 mL / min and the heating rate of 5 °C / min were heated to 700 °C for reduction and roasting for 120 min to obtain the roasting product .
[0061] ( 3 ) Magnetic separation .
[0062] 4 wt% sodium metapphosphate was added to the roasting product for 30 min, and then the product was prepared into slurry, and the water added was 5 times of the mass of the solid material to obtain the intermediate slurry. Under the condition of magnetic separation intensity of 2000 Gs, the intermediate slurry was separated by magnetic separation, and the magnetic material and non-magnetic material were obtained after filtering and drying treatment, in which the magnetic material was the iron concentrate product.
[0063] Embodiment 2
[0064] Different from Example 1, the biochar in this embodiment uses corn straw as raw material, and the preparation process is as follows:
[0065] (T) The corn straw is broken to less than 3 cm, the surface impurities are removed by deionized water, and then dried at 90°C for 500 min;
[0066] @ Under nitrogen atmosphere, the temperature was heated to 400°C at a heating rate of 3°C / min for 120 min, and then naturally cooled to room temperature;
[0067] @ Under carbon dioxide atmosphere, the temperature was heated to 550°C at a heating rate of 3°C / min for 60 min, and then naturally cooled to room temperature;
[0068] (?) It was crushed with a ball mill, passed through a 300 mesh screen, washed with deionized water for 3 times to remove impurities, and then dried at 120 °C for 720 min to obtain biochar.
[0069] Embodiment 3
[0070] Different from Embodiment 1, step (2) in this example is specific as follows:
[0071] The hydrometallurgical slag of laterite nickel ore, 4 wt% biochar and 5 wt% additive (mass ratio of Na2COs to NaOH is 1:1) are ball milled uniformly in a ball mill for 100 min. The material obtained after ball milling was placed in an atmosphere furnace, and heated up to 600°C at argon flow rate of 3 mL / min and heating rate of 3°C / min to reduce and roast for 180 min to obtain the roasted product.
[0072] Comparative example 1
[0073] Different from Embodiment 1, this example uses coke as reducing agent and includes the following steps:
[0074] (1) Reduction roasting.
[0075] The hydrometallurgical slag of laterite nickel ore, 3 wt% coke and 5 wt% Na2CO3 were ball milled uniformly in a ball mill for 70 min. The material obtained after ball milling was placed in an atmosphere furnace , and heated up to 700°C at the argon flow rate of 3 mL / min and the heating rate of 5°C / min to reduce and roast for 120 min to obtain the roasted product .
[0076] ( 2 ) Magnetic separation .
[0077] 4 wt% sodium metapphosphate was added to the roasting product for 30 min, and then the product was prepared into slurry, and the water added was 5 times of the mass of the solid material to obtain the intermediate slurry . Under the condition of magnetic separation intensity of 2000 Gs , the intermediate slurry was separated by magnetic separation, and the magnetic material and non-magnetic material were obtained after filtering and drying treatment , in which the magnetic material was the iron concentrate product .
[0078] Comparative example 2
[0079] Di f ferent from Embodiment 1 , the preparation process of biochar in this comparative example is as follows :
[0080] (T) The coconut shell is broken to less than 3 cm, the surface impurities are removed by deioni zed water, and then dried at 100°C for 480 min;
[0081] @ Under nitrogen atmosphere , the temperature was heated to 500°C at a heating rate of 5°C / min for 120 min, and then natural ly cooled to room temperature ;
[0082] @ It was crushed with a ball mill , passed through a 200 mesh screen, washed with deioni zed water for 3 times to remove impurities , and then dried at 120 °C for 720 min to obtain biochar .
[0083] Comparative example 3
[0084] Di f ferent from Embodiment 1 , there is no additive in step ( 2 ) in this comparative example , which is speci fied as follows .
[0085] The laterite nickel hydrometallurgical slag and 3 wt% biochar were ball milled in a ball mill for 70 min . The material obtained after ball milling was placed in the atmosphere furnace , and the argon flow rate of 3 mL / min and the heating rate of 5 °C / min were heated to 700 °C for reduction and roasting for 120 min to obtain the roasting product .
[0086] Comparative example 4
[0087] Di f ferent from Embodiment 1 , in this comparative example , step ( 2 ) is :
[0088] The laterite nickel hydrometallurgical slag, 3 wt% biochar and 5wt%Na2CO3 were ball milled uni formly in a ball mill for 70 min . The material obtained after ball milling was placed in the atmosphere furnace , and the nitrogen flow rate of 3 mL / min and the heating rate of 5 °C / min were heated to 700 °C for 120 min to obtain the calcined product .
[0089] The iron concentrate obtained in each embodiment and comparative example is analyzed and its rate of recovery and purity are calculated, as detailed in Table 2 .
[0090] Table 2 Recovery ef fects under di f ferent treatment methods
[0091] According to the above results , the biochar prepared by the special method in this application and the iron concentrate extraction method in this application can better reali ze the recovery of iron concentrate from the laterite nickel ore hydrometallurgical slag, and this method has the characteristics of environment- friendly, low cost and high cost performance , and has a good application prospect .
[0092] It should be noted that the above embodiment is only a part of the embodiment of this Application but not all embodiments , and is only used to illustrate the technical scheme of this Application but not to limit it ; Based on the embodiments in this APPLICATION, all other embodiments obtained by ordinary technicians in the field without creative labor shall fall within the scope of protection in this application .
Claims
Claims1. An extraction method of iron concentrate from laterite nickel ore hydrometallurgical slag is characterized by the following steps:
51. The biomass was heated to 350-600°C under nitrogen atmosphere for 80-160 min, naturally cooled, and then heated to 350-600°C under carbon dioxide atmosphere for 40-70 min, naturally cooled, grated and sieved to obtain the biomass charcoal;52 . The laterite nickel hydrometallurgical slag, biochar and additives are mixed and reduced and roasting to obtain the roasting product ;53 . Add dispersants to the roasting products, add water to prepare slurry after ball milling, and dry the iron concentrate after magnetic separation .
2. According to claim 1, the method is characterized in that step SI is:
511. The biomass is initially broken, washed with water to remove impurities, and dried at 90-100°C for 400-520 min;512. In the nitrogen atmosphere, with the heating rate of l-5°C / min heating to 350-600°C treatment 80-160 min, natural cooling to room temperature (15-35°C) ;513. In the carbon dioxide atmosphere, with the heating rate of l-5°C / min heating to 350-600°C activation treatment 40-70 min, natural cooling to room temperature;514. After grinding through 40-300 mesh sieve, wash with water to remove impurities, and then dry at 110-120°C for 680-800 min, to obtain biochar.
3. According to claim 2, the method is characterized in that the biomass is one or more of coconut husks, wheat stalks, corn stalks, bamboo, rice stalks, peanut husks and branches.
4. According to claim 1, the method is characterized in that the amount of biochar added is 2-5 wt% of the mass of laterite nickel ore hydrometallurgical slag.
5. According to claim 1, the method is characterized in that the additive is Na2COs and / or NaOH.
6. According to claim 5, the method is characterized in that the amount of the additive is 4-6 wt% of the mass of the laterite nickel ore hydrometallurgical slag.
7. According to claim 1, the method is characterized in that the mixing method described in step S2 is ball milling.
8. According to claim 1, the method is characterized in that the reduction roasting described in step S2 is as follows: under argon atmosphere, 3-6°C / min heating to 500-900°C reduction roasting for 30-180 min.
9. According to claim 1, the method is characterized in that the dispersing agent is one or more of the proportions of sodium metaphosphorate, sodium hexametaphosphorate, sodium silicate, caustic starch and salinized sodium silicate, and the amount of dispersing agent added is 3-5 wt% of the mass of the roasting product.
10. According to claim 1, the method is characterized in that the strength of the magnetic separation is 1000-3000 Gs .