Method for recovering hydrometallurgical residue of lateritic nickel ore

Abstract

The present application provides a method for recovering hydrometallurgical residue of lateritic nickel ore. The method comprises: (1) subjecting hydrometallurgical residue of lateritic nickel ore to an alkali leaching treatment, so as to obtain a first leachate and a first leach residue; and subjecting the first leachate to evaporative crystallization, so as to obtain a sodium sulfate product; (2) subjecting the first leach residue to a water leaching treatment, and introducing carbon dioxide, so as to obtain a second leachate and a second leach residue; and subjecting the second leachate to evaporative crystallization, so as to obtain a calcium carbonate product; (3) mixing the second leach residue, a carbonaceous reducing agent and a fluxing agent, performing reduction roasting, crushing same, and then performing a size mixing treatment, so as to obtain an intermediate slurry; and (4) subjecting the intermediate slurry to magnetic separation, so as to obtain a magnetic substance and a non-magnetic substance, wherein the magnetic substance is an iron ore concentrate product, and the non-magnetic substance is used for producing a building material or a cement product. The recovery method provided in the present application achieves the recycling of iron resources, and improves the resource utilization rate of lateritic nickel ore, while simplifying the process flow, and avoiding environmental pollution.

Description

Red mud nickel ore smelting slag recovery method TECHNICAL FIELD

[0001] The application belongs to the technical field of solid waste treatment, and relates to a smelting slag recovery method, in particular to a red mud nickel ore smelting slag recovery method. BACKGROUND

[0002] The Fe and Co contents are high, and the Ni and Mg contents are low in the limonitic red mud nickel ore, and the main intermediate product obtained by the hydrometallurgical process is sulfide nickel-cobalt or nickel-cobalt hydroxide. Since the nickel reserves of the limonitic red mud nickel ore account for 70% of the total resource reserves of the red mud nickel ore, the development and utilization thereof is paid more and more attention.

[0003] After the common limonitic red mud nickel ore is treated by acid leaching hydrometallurgy, a lot of smelting slag is often generated, and the iron content thereof is as high as 50%, and hematite exists. The iron grade of the smelting slag cannot reach the metallurgical raw material standard of a steel plant, and the conventional treatment method has the problems of complex process flow and high cost, and it is difficult to realize resource utilization, and is not conducive to environmental protection.

[0004] Therefore, how to provide a red mud nickel ore smelting slag recovery method, realize the recycling of iron resources, further improve the resource utilization rate of the red mud nickel ore, simplify the process flow, avoid environmental pollution, and become the urgent problem to be solved by the technical personnel in the field at present.

[0005] SUMMARY

[0006] The following is a summary of the subject matter described in detail in this document. This summary is not intended to limit the scope of protection of the claims.

[0007] The application provides a red mud nickel ore smelting slag recovery method, which realizes the recycling of iron resources, improves the resource utilization rate of the red mud nickel ore, simplifies the process flow, avoids environmental pollution, and is conducive to large-scale popularization and application.

[0008] The application provides a red mud nickel ore smelting slag recovery method, which comprises the following steps:

[0009] (1) performing alkali leaching treatment on the red mud nickel ore smelting slag to obtain a first leaching liquid and a first leaching residue; the first leaching liquid is evaporated and crystallized to obtain a sodium sulfate product;

[0010] (2) performing water leaching treatment on the first leaching residue, and introducing carbon dioxide to obtain a second leaching liquid and a second leaching residue; the second leaching liquid is evaporated and crystallized to obtain a calcium carbonate product;

[0011] (3) mixing the second leaching residue, the carbonaceous reducing agent and the fluxing agent to perform reduction roasting, and then crushing and performing slurry treatment to obtain intermediate slurry;

[0012] (4) performing magnetic separation on the intermediate slurry to obtain magnetic substances and non-magnetic substances; the magnetic substances are iron concentrate products, and the non-magnetic substances are used to produce building materials or cement products.

[0013] In the step (1), the laterite nickel ore wet smelting residue is an acid leaching residue of the laterite nickel ore after sulfuric acid wet smelting; and the alkali liquor solute used in the alkali leaching treatment includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate or sodium hydroxide, and a typical but non-limiting combination includes a combination of sodium carbonate and sodium bicarbonate, a combination of sodium bicarbonate and sodium hydroxide, a combination of sodium carbonate and sodium hydroxide, or a combination of sodium carbonate, sodium bicarbonate and sodium hydroxide.

[0014] The recovery method provided in the application can recover iron concentrate products from the laterite nickel ore wet smelting residue while obtaining sodium sulfate products and calcium carbonate products through sequentially performed alkali leaching treatment, water leaching treatment, reduction roasting and magnetic separation, and the obtained non-magnetic substances are used to produce building materials or cement products, thereby improving the resource utilization rate and economic benefits of the laterite nickel ore, and the whole recovery process is simple and efficient, which better solves the environmental problems caused by long-term stacking and landfill of the laterite nickel ore wet smelting residue, avoids environmental pollution, and is conducive to large-scale popularization and application.

[0015] In one embodiment, the total iron oxide content in the laterite nickel ore wet smelting residue in the step (1) is 28-50 wt%, for example, can be 28 wt%, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, 40 wt%, 42 wt%, 44 wt%, 46 wt%, 48 wt% or 50 wt%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0016] In the application, the total iron oxide content specifically refers to the content of all iron oxides including FeO, Fe2O3 and Fe3O4.

[0017] In one embodiment, the alkali liquor concentration used in the alkali leaching treatment in the step (1) is 1-2 mol / L, for example, can be 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L or 2 mol / L, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0018] In one embodiment, the solid-liquid ratio of the alkali leaching treatment of step (1) is 1 g: (4-10) mL, for example, it can be 1 g:4 mL, 1 g:5 mL, 1 g:6 mL, 1 g:7 mL, 1 g:8 mL, 1 g:9 mL or 1 g:10 mL, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0019] In one embodiment, the temperature of the alkali leaching treatment of step (1) is 70-95℃, for example, it can be 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃ or 95℃, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0020] In one embodiment, the alkali leaching treatment of step (1) is accompanied by stirring, and the stirring rate is 200-400 rpm, for example, it can be 200 rpm, 220 rpm, 240 rpm, 260 rpm, 280 rpm, 300 rpm, 320 rpm, 340 rpm, 360 rpm, 380 rpm or 400 rpm, and the stirring time is 100-140 min, for example, it can be 100 min, 105 min, 110 min, 115 min, 120 min, 125 min, 130 min, 135 min or 140 min, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0021] In one embodiment, the temperature of the evaporation crystallization of step (1) is 85-95℃, for example, it can be 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃ or 95℃, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0022] In one embodiment, the time of the evaporation crystallization of step (1) is 160-200 min, for example, it can be 160 min, 165 min, 170 min, 175 min, 180 min, 185 min, 190 min, 195 min or 200 min, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0023] In one embodiment, the solid-liquid ratio of the water leaching treatment of step (2) is 1 g: (4-10) mL, for example, it can be 1 g:4 mL, 1 g:5 mL, 1 g:6 mL, 1 g:7 mL, 1 g:8 mL, 1 g:9 mL or 1 g:10 mL, but not limited to the listed values, other values not listed in the range are also applicable.

[0024] In one embodiment, the temperature of the water leaching treatment of step (2) is 15-35℃, for example, it can be 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃ or 35℃, but not limited to the listed values, other values not listed in the range are also applicable.

[0025] In one embodiment, the carbon dioxide of step (2) is bubbled until the solution becomes clear.

[0026] In one embodiment, the temperature of the evaporative crystallization of step (2) is 85-95℃, for example, it can be 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃ or 95℃, but not limited to the listed values, other values not listed in the range are also applicable.

[0027] In one embodiment, the time of the evaporative crystallization of step (2) is 160-200 min, for example, it can be 160 min, 165 min, 170 min, 175 min, 180 min, 185 min, 190 min, 195 min or 200 min, but not limited to the listed values, other values not listed in the range are also applicable.

[0028] In one embodiment, the second leaching residue of step (3) is sequentially dried, crushed and finely ground before being subjected to the reduction roasting.

[0029] In one embodiment, the carbonaceous reducing agent of step (3) comprises any one or a combination of at least two of coke, activated carbon, anthracite or lignite, typical but non-limiting combinations include a combination of coke and activated carbon, a combination of activated carbon and anthracite, a combination of anthracite and lignite, a combination of coke, activated carbon and anthracite, a combination of activated carbon, anthracite and lignite, or a combination of coke, activated carbon, anthracite and lignite.

[0030] In one embodiment, the carbon content of the carbonaceous reductant of step (3) is 70-100 wt%, for example, it can be 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt% or 100 wt%, but not limited to the listed values, other values not listed within the range are also applicable.

[0031] In one embodiment, the fluxing agent of step (3) comprises sodium carbonate and / or sodium hydroxide.

[0032] In one embodiment, the mixing amount of the carbonaceous reductant is 8-12 wt% based on the mass of the second leaching residue, for example, it can be 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt% or 12 wt%, and the mixing amount of the fluxing agent is 10-20 wt%, for example, it can be 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt% or 20 wt%, but not limited to the listed values, other values not listed within the range are also applicable.

[0033] In one embodiment, the temperature of the reduction roasting of step (3) is 700-900 °C, for example, it can be 700 °C, 720 °C, 740 °C, 760 °C, 780 °C, 800 °C, 820 °C, 840 °C, 860 °C, 880 °C or 900 °C, but not limited to the listed values, other values not listed within the range are also applicable.

[0034] In one embodiment, the heating rate of the reduction roasting of step (3) is 4-6 °C / min, for example, it can be 4 °C / min, 4.2 °C / min, 4.4 °C / min, 4.6 °C / min, 4.8 °C / min, 5 °C / min, 5.2 °C / min, 5.4 °C / min, 5.6 °C / min, 5.8 °C / min or 6 °C / min, but not limited to the listed values, other values not listed within the range are also applicable.

[0035] In one embodiment, the holding time of the reduction roasting of step (3) is 50-140 min, for example, it can be 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min or 140 min, but not limited to the listed values, other values not listed within the range are also applicable.

[0036] In the present application, the reduction roasting in step (3) is carried out in a crucible in a high-temperature tube furnace, and the crucible can be selected from a corundum crucible or a graphite crucible.

[0037] In one embodiment, after the crushing in step (3), a fine grinding treatment is further carried out, and the fine grinding is to an average particle size of 150-250 mesh, for example, it can be 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh, 200 mesh, 210 mesh, 220 mesh, 230 mesh, 240 mesh or 250 mesh, but is not limited to the listed values, and other values not listed in this range are also applicable.

[0038] In one embodiment, the amount of water added in the slurry treatment in step (3) is 4-6 times the mass of the solid material, for example, it can be 4 times, 4.2 times, 4.4 times, 4.6 times, 4.8 times, 5 times, 5.2 times, 5.4 times, 5.6 times, 5.8 times or 6 times, but is not limited to the listed values, and other values not listed in this range are also applicable.

[0039] In one embodiment, the magnetic separation in step (4) is carried out at a magnetic field strength of 1000-3000Gs, for example, it can be 1000Gs, 1200Gs, 1400Gs, 1600Gs, 1800Gs, 2000Gs, 2200Gs, 2400Gs, 2600Gs, 2800Gs or 3000Gs, but is not limited to the listed values, and other values not listed in this range are also applicable.

[0040] In one embodiment, the magnetic substance and the non-magnetic substance in step (4) are independently subjected to filtration and drying treatment.

[0041] As an optional technical solution of the present application, the recovery method comprises the following steps:

[0042] (1) The laterite nickel ore wet smelting slag is subjected to alkali leaching treatment with an alkali solution having a concentration of 1-2 mol / L, and the solid-liquid ratio of the alkali leaching treatment is controlled to be 1g:(4-10)mL, the temperature is 70-95℃, and the treatment is accompanied by stirring at a speed of 200-400rpm for 100-140min, to obtain a first leaching liquid and a first leaching residue; the first leaching liquid is subjected to evaporation crystallization at 85-95℃ for 160-200min to obtain a sodium sulfate product; the laterite nickel ore wet smelting slag is an acid leaching residue obtained after sulfuric acid wet smelting of laterite nickel ore, and the total iron oxide content in the acid leaching residue is 28-50wt%; the solutes of the alkali solution include any one or a combination of at least two of sodium carbonate, sodium bicarbonate or sodium hydroxide;

[0043] (2) performing water leaching treatment on the first leaching residue at 15-35℃ according to a solid-liquid ratio of 1g:(4-10)mL, and passing carbon dioxide until the solution becomes clear, to obtain a second leaching residue and a second leaching solution; the second leaching solution is evaporated and crystallized at 85-95℃ for 160-200min to obtain a calcium carbonate product;

[0044] (3) sequentially subjecting the second leaching residue to drying, crushing and fine grinding, then mixing the second leaching residue, a carbonaceous reducing agent and a fluxing agent, heating at a rate of 4-6℃ / min to 700-900℃ for reduction roasting for 50-140min, crushing and fine grinding to an average particle size of 150-250mesh, then performing slurry treatment, and the water addition amount is 4-6 times the mass of the solid material, to obtain an intermediate slurry; the carbonaceous reducing agent includes any one or a combination of at least two of coke, activated carbon, anthracite or lignite, and the carbon content is 70-100wt%; the fluxing agent includes sodium carbonate and / or sodium hydroxide; the mixing amount of the carbonaceous reducing agent is 8-12wt% and the mixing amount of the fluxing agent is 10-20wt% based on the mass of the second leaching residue as the calculation basis;

[0045] (4) performing magnetic separation on the intermediate slurry under a magnetic field strength of 1000-3000Gs, and after filtration and drying treatment, obtaining magnetic substances and non-magnetic substances; the magnetic substances are iron concentrate products, and the non-magnetic substances are used to produce building materials or cement products.

[0046] The numerical ranges described herein also include any point or value within the range, whether specifically stated or not, and limits are used only to the extent that some ranges are inclusive of their endpoints, and that other ranges are exclusive of their endpoints. In view of the above, it will be seen that the several objects of the application are achieved.

[0047] Compared with the related art, the present application has the following beneficial effects:

[0048] The recovery method provided by the present application recovers iron concentrate products from laterite nickel ore hydrometallurgy residues while obtaining sodium sulfate products and calcium carbonate products through sequentially performed alkali leaching treatment, water leaching treatment, reduction roasting and magnetic separation, and the obtained non-magnetic substances are used to produce building materials or cement products, thereby improving the resource utilization rate and economic benefits of laterite nickel ore, the whole recovery process is simple and efficient, and the environmental problems caused by long-term stacking and landfill of laterite nickel ore hydrometallurgy residues are better solved, environmental pollution is avoided, and large-scale popularization and application are facilitated.

[0049] Other aspects can become apparent from the following drawings and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0050] The accompanying drawings are used to provide further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0051] FIG. 1 is a flowchart of a recovery method of a laterite nickel ore hydrometallurgy slag provided by embodiments 1-5. DETAILED DESCRIPTION

[0052] The technical solutions of the present application are further illustrated below through specific embodiments. It should be understood by those skilled in the art that the embodiments are only used to help understand the present application, and should not be regarded as a specific limitation on the present application.

[0053] Embodiment 1

[0054] The present embodiment provides a recovery method of a laterite nickel ore hydrometallurgy slag, as shown in FIG. 1, the recovery method comprises the following steps:

[0055] (1) The laterite nickel ore hydrometallurgy slag is subjected to alkali leaching treatment by using a sodium carbonate solution with a concentration of 1.5 mol / L, and the solid-liquid ratio of the alkali leaching treatment is controlled to be 1 g:8 mL, the temperature is 90°C, and at the same time, stirring is accompanied at a speed of 300 rpm for 120 min, to obtain a first leaching solution and a first leaching residue; the first leaching solution is subjected to evaporation crystallization at 90°C for 180 min to obtain a sodium sulfate product; the laterite nickel ore hydrometallurgy slag is an acid leaching residue after a brown iron type laterite nickel ore is subjected to sulfuric acid hydrometallurgy, and the total iron oxide content in the acid leaching residue is 42 wt%;

[0056] (2) The first leaching residue is subjected to water leaching treatment at 20°C according to a solid-liquid ratio of 1 g:8 mL, and carbon dioxide is introduced until the solution becomes clear, to obtain a second leaching solution and a second leaching residue; the second leaching solution is subjected to evaporation crystallization at 90°C for 180 min to obtain a calcium carbonate product;

[0057] (3) The second leaching residue is sequentially subjected to drying, crushing and fine grinding, and then the second leaching residue, coke (carbon content is 70%) and sodium carbonate are mixed, and the mixing amount of coke is 10 wt% and the mixing amount of sodium carbonate is 15 wt% based on the mass of the second leaching residue as a calculation basis, and the temperature is increased to 900°C at a rate of 5°C / min for reduction roasting for 120 min, and then the second leaching residue is crushed and finely ground to an average particle size of 200 mesh, and then slurry treatment is performed, and the water addition amount is 5 times the mass of the solid material, to obtain an intermediate slurry;

[0058] (4) The intermediate slurry is subjected to magnetic separation under the condition that the magnetic separation strength is 2000 Gs, and after filtration and drying treatment, a magnetic substance and a non-magnetic substance are obtained; the magnetic substance is an iron concentrate product, and the non-magnetic substance is used to produce building materials or cement products.

[0059] Example 2

[0060] The present example provides a recovery method of a laterite nickel ore hydrometallurgy slag, as shown in Figure 1, which comprises the following steps:

[0061] (1) The laterite nickel ore hydrometallurgy slag is subjected to alkali leaching treatment with a sodium hydroxide solution with a concentration of 1 mol / L, and the solid-liquid ratio of the alkali leaching treatment is controlled to be 1 g:6 mL, the temperature is 80℃, and it is accompanied by stirring at a rate of 200 rpm for 140 min to obtain a first leaching solution and a first leaching residue; the first leaching solution is subjected to evaporation crystallization at 85℃ for 200 min to obtain a sodium sulfate product; the laterite nickel ore hydrometallurgy slag is an acid leaching residue after sulfuric acid hydrometallurgy of a limonitic type laterite nickel ore, and the total iron oxide content therein is 28wt%;

[0062] (2) The first leaching residue is subjected to water leaching treatment at 15℃ according to a solid-liquid ratio of 1 g:6 mL, and carbon dioxide is introduced until the solution becomes clear to obtain a second leaching solution and a second leaching residue; the second leaching solution is subjected to evaporation crystallization at 85℃ for 200 min to obtain a calcium carbonate product;

[0063] (3) The second leaching residue is sequentially subjected to drying, crushing and fine grinding, and then the second leaching residue, activated carbon (carbon content of 75%) and sodium hydroxide are mixed, and the mixing amount of activated carbon is 8wt% and the mixing amount of sodium hydroxide is 10wt% based on the mass of the second leaching residue as the calculation basis, and the temperature is increased to 800℃ at a rate of 4℃ / min for reduction roasting for 90 min, and then crushed and finely ground to an average particle size of 150 mesh, and then subjected to slurry treatment, and the water addition amount is 4 times the mass of the solid material to obtain an intermediate slurry;

[0064] (4) The intermediate slurry is subjected to magnetic separation under a magnetic separation intensity of 1000 Gs, and after filtration and drying treatment, a magnetic substance and a non-magnetic substance are obtained; the magnetic substance is an iron concentrate product, and the non-magnetic substance is used to produce building materials or cement products.

[0065] Example 3

[0066] The present example provides a recovery method of a laterite nickel ore hydrometallurgy slag, as shown in Figure 1, which comprises the following steps:

[0067] (1) the red soil nickel ore wet smelting slag is subjected to alkali leaching treatment by using a sodium bicarbonate solution with a concentration of 2 mol / L, and the solid-liquid ratio of the alkali leaching treatment is controlled to be 1 g:4 mL, the temperature is 70℃, and the stirring is accompanied by a speed of 400 rpm for 100 min to obtain a first leaching solution and a first leaching residue; the first leaching solution is subjected to evaporation crystallization at 95℃ for 160 min to obtain a sodium sulfate product; the red soil nickel ore wet smelting slag is an acid leaching residue obtained after a brown iron type red soil nickel ore is subjected to sulfuric acid wet smelting, and the total iron oxide content in the acid leaching residue is 50 wt%;

[0068] (2) the first leaching residue is subjected to water leaching treatment at 35℃ according to a solid-liquid ratio of 1 g:4 mL, and carbon dioxide is introduced until the solution becomes clear to obtain a second leaching solution and a second leaching residue; the second leaching solution is subjected to evaporation crystallization at 95℃ for 160 min to obtain a calcium carbonate product;

[0069] (3) the second leaching residue is sequentially subjected to drying, crushing and fine grinding, and then the second leaching residue, anthracite (carbon content is 80%) and sodium carbonate are mixed, and the mass of the second leaching residue is taken as the calculation basis, the mixing amount of the anthracite is 12 wt%, and the mixing amount of the sodium carbonate is 20 wt%, the temperature is increased to 700℃ at a rate of 6℃ / min for reduction roasting for 100 min, and then the second leaching residue is crushed and finely ground to an average particle size of 250 mesh, and then slurry treatment is performed, and the water amount is 6 times the mass of the solid material to obtain an intermediate slurry;

[0070] (4) the intermediate slurry is subjected to magnetic separation under the condition that the magnetic separation strength is 3000 Gs, and the magnetic material and the non-magnetic material are obtained after filtration and drying treatment; the magnetic material is an iron concentrate product, and the non-magnetic material is used to produce building materials or cement products.

[0071] Example 4

[0072] The example provides a red soil nickel ore wet smelting slag recovery method, and the solid-liquid ratio of the alkali leaching treatment in step (1) is changed to 1 g:3 mL, and the other steps and conditions are the same as those in example 1, so they are not described here.

[0073] Example 5

[0074] The example provides a red soil nickel ore wet smelting slag recovery method, and the temperature of the alkali leaching treatment in step (1) is changed to 60℃, and the other steps and conditions are the same as those in example 1, so they are not described here.

[0075] Example 6

[0076] The example provides a red soil nickel ore wet smelting slag recovery method, and the solid-liquid ratio of the water leaching treatment in step (2) is changed to 1 g:3 mL, and the other steps and conditions are the same as those in example 1, so they are not described here.

[0077] Example 7

[0078] This example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that the mixing amount of coke in step (3) is changed to 6wt%, the rest of the steps and conditions are the same as example 1, so here is not described.

[0079] Example 8

[0080] This example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that the mixing amount of sodium carbonate in step (3) is changed to 8wt%, the rest of the steps and conditions are the same as example 1, so here is not described.

[0081] Example 9

[0082] This example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that the temperature of the reduction roasting in step (3) is changed to 600℃, the rest of the steps and conditions are the same as example 1, so here is not described.

[0083] Example 10

[0084] This example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that the magnetic separation intensity of the magnetic separation in step (4) is changed to 800Gs, the rest of the steps and conditions are the same as example 1, so here is not described.

[0085] Comparative Example 1

[0086] This comparative example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that no carbon dioxide is passed in step (2), the rest of the steps and conditions are the same as example 1, so here is not described.

[0087] Comparative Example 2

[0088] This comparative example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that no sodium carbonate is added as a fluxing agent in the reduction roasting process in step (3), the rest of the steps and conditions are the same as example 1, so here is not described.

[0089] Comparative Example 3

[0090] This comparative example provides a method for recycling the residue of a laterite nickel ore hydrometallurgical smelting, except that no slurry treatment is performed in step (3), i.e. the dry magnetic separation is directly performed on the material particles obtained after crushing, the rest of the steps and conditions are the same as example 1, so here is not described.

[0091] After testing and analysis, the yield and purity of the sodium sulfate product, calcium carbonate product and iron concentrate product obtained in examples 1-10 and comparative examples 1-3 are shown in Table 1 below.

[0092] Table 1

[0093] It can be seen that the recovery method provided by the application recovers the iron concentrate product from the laterite nickel ore wet smelting slag while obtaining the sodium sulfate product and the calcium carbonate product through the sequentially performed alkali leaching treatment, water leaching treatment, reduction roasting and magnetic separation, and the obtained non-magnetic material is used for producing building materials or cement products, thereby improving the resource utilization rate and economic benefits of the laterite nickel ore, the whole recovery process is simple and efficient, and the environmental problems caused by long-term stacking and landfill of the laterite nickel ore wet smelting slag are better solved, environmental pollution is avoided, and large-scale popularization and application are facilitated.

[0094] The applicant declares that the above description is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, and it should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the application can be easily thought of by any person skilled in the art in the technical field, and all fall within the protection scope and disclosure scope of the application.

Claims

1. A method for recycling a residue of a laterite nickel ore hydrometallurgy, comprising the following steps: (1) performing an alkali leaching treatment on the residue of the laterite nickel ore hydrometallurgy to obtain a first leaching solution and a first leaching residue; the first leaching solution is evaporated and crystallized to obtain a sodium sulfate product; (2) performing a water leaching treatment on the first leaching residue and introducing carbon dioxide to obtain a second leaching solution and a second leaching residue; the second leaching solution is evaporated and crystallized to obtain a calcium carbonate product; (3) mixing the second leaching residue, a carbonaceous reducing agent and a fluxing agent to perform a reduction roasting, and then performing a slurry treatment after crushing to obtain an intermediate slurry; (4) performing a magnetic separation on the intermediate slurry to obtain magnetic substances and non-magnetic substances; the magnetic substances are a iron concentrate product, and the non-magnetic substances are used to produce a building material or a cement product; In the step (1), the residue of the laterite nickel ore hydrometallurgy is an acid leaching residue of the laterite nickel ore after a sulfuric acid hydrometallurgy; and the alkali solution solute used in the alkali leaching treatment includes any one or a combination of at least two of sodium carbonate, sodium bicarbonate or sodium hydroxide.

2. The recycling method of claim 1, wherein, The total iron oxide content in the residue of the laterite nickel ore hydrometallurgy in the step (1) is 28-50wt%. Optionally, the alkali solution concentration used in the alkali leaching treatment in the step (1) is 1-2mol / L. Optionally, the solid-liquid ratio of the alkali leaching treatment in the step (1) is 1g:(4-10)mL. Optionally, the temperature of the alkali leaching treatment in the step (1) is 70-95℃. Optionally, the alkali leaching treatment in the step (1) is accompanied by stirring, and the stirring rate is 200-400rpm, and the stirring time is 100-140min.

3. The recycling method according to claim 1 or 2, wherein, The temperature of the evaporation crystallization in the step (1) is 85-95℃. Optionally, the time of the evaporation crystallization in the step (1) is 160-200min.

4. The recovery method according to any one of claims 1 to 3, wherein, The solid-liquid ratio of the water leaching treatment in the step (2) is 1g:(4-10)mL. Optionally, the temperature of the water leaching treatment in the step (2) is 15-35℃. Optionally, the carbon dioxide is introduced until the solution becomes clear in the step (2).

5. The recycling method according to any one of claims 1 to 4, wherein, The temperature of the evaporation crystallization in the step (2) is 85-95℃. Optionally, the time of the evaporation crystallization in the step (2) is 160-200min.

6. The recycling method according to any one of claims 1 to 5, wherein, The second leaching residue in the step (3) is sequentially dried, crushed and finely ground before the reduction roasting. Optionally, the carbonaceous reducing agent in the step (3) includes any one or a combination of at least two of coke, activated carbon, anthracite or lignite. Optionally, the carbon content of the carbonaceous reducing agent in the step (3) is 70-100wt%. Optionally, the fluxing agent in the step (3) includes sodium carbonate and / or sodium hydroxide. Optionally, the mixing amount of the carbonaceous reducing agent is 8-12wt%, and the mixing amount of the fluxing agent is 10-20wt% based on the mass of the second leaching residue.

7. The recycling method according to any one of claims 1 to 6, wherein, The temperature of the reduction roasting in the step (3) is 700-900℃. Optionally, the heating rate of the reduction roasting in the step (3) is 4-6℃ / min. Optionally, the holding time of the reduction roasting in the step (3) is 50-140min.

8. The recycling method according to any one of claims 1 to 7, wherein, The crushing in step (3) is followed by fine grinding, and the average particle size of the fine grinding is 150-250 mesh; Optionally, the water addition amount in the slurrying in step (3) is 4-6 times the mass of the solid material.

9. The recycling method according to any one of claims 1 to 8, wherein, The magnetic separation in step (4) is performed at a magnetic field strength of 1000-3000 Gs. Optionally, the magnetic substance and the non-magnetic substance in step (4) are independently subjected to filtration and drying.

10. The recovery method according to any one of claims 1-9, comprising the following steps: (1) subjecting the residue from the hydrometallurgical smelting of laterite nickel ore to alkali leaching treatment with an alkali solution having a concentration of 1-2 mol / L, and controlling the solid-liquid ratio of the alkali leaching treatment to be 1 g:(4-10) mL, the temperature to be 70-95°C, and the stirring rate to be 200-400 rpm for 100-140 min to obtain a first leaching solution and a first leaching residue; the first leaching solution is subjected to evaporation crystallization at 85-95°C for 160-200 min to obtain a sodium sulfate product; the residue from the hydrometallurgical smelting of laterite nickel ore is an acid leaching residue obtained after the hydrometallurgical smelting of laterite nickel ore with sulfuric acid, and the total iron oxide content in the residue is 28-50 wt%; the solutes of the alkali solution include any one or a combination of at least two of sodium carbonate, sodium bicarbonate or sodium hydroxide; (2) subjecting the first leaching residue to water leaching treatment at a solid-liquid ratio of 1 g:(4-10) mL at 15-35°C, and passing in carbon dioxide until the solution becomes clear to obtain a second leaching solution and a second leaching residue; the second leaching solution is subjected to evaporation crystallization at 85-95°C for 160-200 min to obtain a calcium carbonate product; (3) sequentially subjecting the second leaching residue to drying, crushing and fine grinding, then mixing the second leaching residue, a carbonaceous reducing agent and a fluxing agent, heating at a rate of 4-6°C / min to 700-900°C for reduction roasting for 50-140 min, crushing and fine grinding to an average particle size of 150-250 mesh, then performing slurrying treatment with a water addition amount of 4-6 times the mass of the solid material to obtain an intermediate slurry; the carbonaceous reducing agent includes any one or a combination of at least two of coke, activated carbon, anthracite or lignite, and the carbon content is 70-100 wt%; the fluxing agent includes sodium carbonate and / or sodium hydroxide; based on the mass of the second leaching residue as the calculation basis, the mixing amount of the carbonaceous reducing agent is 8-12 wt%, and the mixing amount of the fluxing agent is 10-20 wt%; (4) performing magnetic separation of the intermediate slurry at a magnetic field strength of 1000-3000 Gs, and then filtering and drying to obtain a magnetic substance and a non-magnetic substance; the magnetic substance is an iron concentrate product, and the non-magnetic substance is used to produce building materials or cement products.

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