A combined beneficiation method for laterite nickel ore

Abstract

The present invention discloses a combined beneficiation method for laterite nickel ore, comprising the following steps: subjecting the raw ore to a washing process and a first-stage cyclone separation in sequence, subjecting the first-stage cyclone underflow to spiral chute classification, multi-stage shaking table classification, weak magnetic separation and spiral classification in sequence, so as to obtain a first chrome concentrate, a first chrome middling, a second weak magnetic separation middling and a mixed light ore. subjecting the mixed light ore to ball milling and stirring treatment, and then subjecting it to a second-stage cyclone separation. subjecting the second-stage cyclone underflow to weak magnetic separation, subjecting the weak magnetic separation magnetic material to shaking table classification and spiral classification to obtain a second chrome concentrate, subjecting the weak magnetic separation non-magnetic material to strong magnetic separation to obtain a strong magnetic separation non-magnetic material and a strong magnetic separation magnetic material. mixing the strong magnetic separation magnetic material with the second weak magnetic separation middling, ball milling and then recycling them to the ball milling and stirring process, and mixing the first-stage cyclone overflow, the second-stage cyclone overflow and the strong magnetic separation non-magnetic material and using them to prepare a high-pressure leaching stock solution. through the combined process of the present invention, the recovery rate of chromium is high, which is beneficial to reducing the chromium removal pressure in the laterite nickel ore wet smelting process.

Description

[0001] Description

[0002] A COMBINED BENEFICIATION METHOD FOR LATERITE NICKEL ORE

[0003] Field Of Invention

[0004] The present invention relates to the technical field of mineral processing, and in particular to a combined mineral processing method for laterite nickel ore .

[0005] Background

[0006] Laterite nickel ore often contains nickel and cobalt . The industry often uses hydrometallurgical processes to develop laterite nickel ore . Since laterite nickel ore often contains about 2 % chromium, these chromium will be converted into Cr6+during the nickel and cobalt leaching process . I f the waste l iquid containing Cr6+is directly discharged, it will cause serious environmental problems . Therefore , after nickel and cobalt leaching, it is necessary to add chromium removal operations , which increases production costs .

[0007] The limonite layer with a lower nickel grade in laterite nickel ore cannot be used in the pyrometallurgical process and can only be processed by hydrometallurgy . Hydrometallurgy, especially high-pressure acid leaching, will cause corrosion to the equipment used . In addition, the associated spinel-type chromite in laterite nickel ore also has a strong abrasive ef fect on the equipment . Therefore , expens ive corrosion-res istant equipment is required when hydrometallurgical processing is used for laterite nickel ore , which increases the equipment cost and brings unpredictable safety risks . For the separation of chromium in laterite nickel ore , the prior art generally adopts a single gravity separation or magnetic separation method, and a single separation method often loses a large part of the chromium .

[0008] Laterite-nickel ore combined beneficiation method for improving chromium recovery . Summary

[0009] In view of this , the present invention provides a laterite-nickel ore combined beneficiation method for solving the problem of how to improve the chromium recovery rate in the laterite-nickel ore beneficiation process .

[0010] In order to achieve the above technical obj ectives , this invention adopts the following technical solutions :

[0011] First , the present invention provides a laterite nickel ore combined beneficiation method, comprising the following steps :

[0012] S I . The raw ore is sequentially subj ected to a washing process and a cyclone separation to obtain a cyclone overflow and a cyclone underflow . The cyclone underflow is sequentially subj ected to spiral chute classi fication, multi-stage shaking table classi fication, and then weak magnetic separation and spiral classi fication to obtain a first chrome concentrate , a first chrome middling, a second weak magnetic separation middling and a mixed light ore .

[0013] S2 . After the mixed light ore is subj ected to ball mill stirring treatment , a two-stage cyclone separation is performed to obtain a second-stage cyclone underflow and a second-stage cyclone overflow , the second-stage cyclone underflow is subj ected to weak magnetic separation to obtain a weak magnetic separation magnetic material and a weak magnetic separation non-magnetic material , the weak magnetic separation magnetic material is subj ected to shaking table classi fication and spiral classi fication to obtain a second chrome concentrate , and the weak magnetic separation non-magnetic material is subj ected to strong magnetic separation to obtain a strong magnetic separation non-magnetic material and a strong magnetic separation magnetic material .

[0014] S3 . The high-intensity magnetic separation magnetic material and the second weak magnetic separation ore are mixed and ball-milled and then reused in the ball milling and stirring process of step S2 . The first-stage cyclone overflow, the second-stage cyclone overflow and the high-intensity magnetic separation non-magnetic material are mixed and used to prepare the high-pressure leaching stock solution .

[0015] Preferably, in step S I , the speci fic steps of the first cyclone separation are : introducing the raw ore into a first cyclone after the ore washing process for first cyclone separation to obtain a first cyclone overflow and a first cyclone underflow, and the first cyclone overflow is processed according to step S3 .

[0016] Preferably, in step S I , the speci fic operation of spiral chute classi fication is : a section of cyclone underflow is merged into the spiral chute to obtain chute light ore and chute heavy ore . The chute light ore is used as a component o f the mixed light ore in step S I for post-processing .

[0017] Preferably, in step S I , the multi-stage shaking table classi fication includes first shaking table classi fication and second shaking table classi fication in sequence .

[0018] The first shaking table classi fication step is : the heavy ore material in the chute is introduced into the first shaking table for first shaking table classi fication to obtain the first shaking table light ore material and the first shaking table heavy ore material .

[0019] The second shaking table classi fication step comprises : trans ferring the heavy ore from the first shaking table to the second shaking table for second shaking table classi fication to obtain light ore from the second shaking table , medium ore from the second shaking table , and heavy ore from the second shaking table .

[0020] The light ore material from the first shaking table and the light ore material from the second shaking table are both treated as components of the mixed light ore material in step S I for post -pro cessing .

[0021] Preferably, in step S I , the steps of weak magnetic separation and spiral classi fication are : the heavy ore material of the second shaking table is introduced into the first weak magnetic separator for the first weak magnetic separation to obtain the first weak magnetic concentrate and the first weak magnetic selected ore , and the first weak magnetic concentrate is introduced into the first spiral classi fier for the first spiral classi fication to obtain the first chromium concentrate . The medium ore material of the second shaking table is introduced into the second weak magnetic separator for the second weak magnetic separation to obtain the second weak magnetic concentrate and the second weak magnetic selected ore , and the first weak magnetic selected ore and the second weak magnetic selected ore are introduced into the second spiral classi fier together for the second spiral classi fication to obtain the first chromium medium ore . The second weak magnetic selected ore is processed according to step S3 . Preferably, the speci fic operation of step S2 is : after the mixed light ore is introduced into a ball mill stirring tank for ball milling and stirring treatment , it is introduced into a second-stage cyclone for second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow is introduced into a third weak magnetic separator for third weak magnetic separation to obtain weak magnetic separation magnetic material and weak magnetic separation non-magnetic material , the weak magnetic separation magnetic material is subj ected to shaking table classi fication and spiral classi fication to obtain a second chromium concentrate , the weak magnetic separation non-magnetic material is introduced into a strong magnetic separator for strong magnetic separation to obtain strong magnetic separation non-magnetic material and strong magnetic separation magnetic material . The second-stage cyclone overflow and the strong magnetic separation non-magnetic material are processed according to step S3 .

[0022] Preferably, the speci fic operation of obtaining the second chromium concentrate by shaking table classi fication and spiral classi fication of the weak magnetic separation magnetic material is : using a weak magnetic separation pump to sequentially transport the weak magnetic separation magnetic material to a third shaking table and a third spiral classi fier for shaking table classi fication and spiral classi fication respectively, to obtain the second chromium concentrate .

[0023] Preferably, in step S2 , the magnetic field strength of the weak magnetic separation is 1000-2000 GS , and the magnetic field strength of the strong magnetic separation is 10000-20000 GS .

[0024] Preferably, in step S3 , the strong magnetic separation magnetic material and the second weak magnetic separation ore are mixed and put into a ball mill for ball milling, and then returned to the ball mill stirring tank of step S2 to continue the ball milling and stirring treatment .

[0025] Preferably, in step S3 , the speci fic steps of preparing the high-pressure leaching stock solution are : conveying the overflow of the first stage cyclone to the finished product tank after passing through a first stage impurity removal screen for impurities removal , and then conveying to the raw ore slurry storage tank . Mixing the overflow of the second stage cyclone with the strong magnetic separation non-magnetic material , and conveying to the raw ore slurry storage tank after passing through a second stage impurity removal screen for impurities removal . And collecting the mixture in the raw ore slurry storage tank into a thickener containing a flocculant for solid-liquid separation to obtain the high-pressure leaching stock solution .

[0026] The beneficial ef fects of the present invention are as follows : the present invention separates the chromite in the laterite nickel ore through a combined process of multi-stage magnetic separation, spiral chute , multi-stage shaking table classi fication, and multi-stage cyclone separation, and the obtained chromite concentrate and chromium middling' s have a high recovery rate and a high grade of the chromium concentrate , which is beneficial to reducing the chromium removal pressure in the wet smelting process of laterite nickel ore and is beneficial to the comprehensive utili zation of the chromium element .

[0027] Brief Description Of The Drawings

[0028] FIG . 1 is a process flow chart of the present invention .

[0029] Detailed Description

[0030] In order to make the purpose , technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conj unction with the embodiments . It should be understood that the speci fic embodiments described here are only used to explain the present invention and are not used to limit the present invention .

[0031] The embodiments and control examples of the present invention all use laterite nickel ore from a tropical rainforest climate island near the equator in Indonesia . The main valuable metal elements of the ore are Ni , Fe and Co , and impurities such as Ca, Mg, Cr2Os and Si02 are also present . The presence of these impurities will increase the acid consumption of hydrometallurgy and form a large amount of acid leaching tailings . The purpose of the present invention i s to separate chromium from di f ferent mineral phases to increase the recovery rate of chromium, thereby improving the comprehensive utili zation rate of laterite nickel ore . Based on this , this invention was created .

[0032] As shown in FIG . 1 , the present invention provides a laterite nickel ore combined beneficiation method, comprising the following steps :

[0033] S I . The raw ore is sequentially subj ected to a washing process and a cyclone separation to obtain a cyclone overflow and a cyclone underflow . The cyclone underflow is sequentially subj ected to spiral chute classi fication, multi-stage shaking table classi fication, and then weak magnetic separation and spiral classi fication to obtain a first chrome concentrate , a first chrome middling, a second weak magnetic separation middling and a mixed light ore .

[0034] S2 . After the mixed light ore is subj ected to ball mill stirring treatment , a two-stage cyclone separation is performed to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow is subj ected to weak magnetic separation to obtain a weak magnetic separation magnetic material and a weak magnetic separation non-magnetic material , the weak magnetic separation magnetic material is subj ected to shaking table classi fication and spiral classi fication to obtain a second chrome concentrate , and the weak magnetic separation non-magnetic material is subj ected to strong magnetic separation to obtain a strong magnetic separation non-magnetic material and a strong magnetic separation magnetic material .

[0035] S3 . The high-intensity magnetic separation magnetic material and the second weak magnetic separation ore are mixed and ball-milled and then reused in the ball milling and stirring process of step S2 . The first-stage cyclone overflow, the second-stage cyclone overflow and the high-intensity magnetic separation non-magnetic material are mixed and used to prepare the high-pressure leaching stock solution .

[0036] In the present invention, in addition to obtaining the first chromium concentrate and the first chromium middling, step S I also obtains the second weak magnetic separation middling and the mixed light ore . Since the mixed light ore and the second weak magnetic separation middling contain limonite and chromite wrapped in the limonite , and both limonite and chromite contain chromium, the present invention performs ball milling and stirring treatment on the mixed light ore to improve the monomer dissociation degree of chromite wrapped in the limonite , so that the chromite and limonite in the mixed light ore are separated, and then the second chromium concentrate is obtained by two-stage cyclone separation and weak magnetic separation . And in order to further improve the first In order to improve the recovery rate and grade of the second chromium concentrate , strong magnetic separation was carried out on the weak magnetic non-magnetic material after weak magnetic separation, and the strong magnetic material obtained by strong magnetic separation was mixed with the second weak magnetic medium and then ball-milled and reused in the ball milling and stirring process . After multiple ball milling, two-stage cyclone , weak magnetic separation and strong magnetic separation, the chromium in the second weak magnetic medium and the limonite and chromite that were leaked in the strong magnetic material was further enriched and separated to screen more second chromium concentrate , which is beneficial to reduce the chromium content in the subsequent high-pressure leaching solution and reduce the pressure of chromium removal in the high-pressure leaching solution .

[0037] In some embodiments , in step S I , the speci fic steps of a cyclone separation are : introducing the raw ore into a cyclone after the ore washing process for a cyclone separation to obtain a cyclone overflow and a cyclone underflow, and the cyclone overflow is processed according to step S3 .

[0038] In this embodiment , in step S I , the speci fic steps of washing the ore include : using a heavy plate feeder to transport the laterite nickel ore to a cylindrical ore washer to remove gravel with a particle si ze greater than 5 cm, and then removing gravel with a particle si ze of 2-5 cm by a double spiral scrubber and a linear vibrating screen to obtain a gravel- free ore . Firstly remove gravel from the ore to reduce the interference of gravel in subsequent ore dressing . After a cyclone separation, the washed ore is divided into a cyclone overflow and a cyclone underflow . Since the grades of Ni and Cr20s do not change synchronously with the particle si ze , most of the chromium-containing impurities are separated in a cyclone underflow .

[0039] In some embodiments , in step S I , the speci fic operation of spiral chute classi fication is : a section of cyclone underflow is merged into the spiral chute to obtain chute light ore and chute heavy ore . The chute light ore is post-processed as a component of the mixed light ore in step S I . In this embodiment , most of the chromium-containing ore phase is separated into the heavy ore material in the chute , while the light ore material in the chute still contains a small amount of chromium ore phase .

[0040] In some embodiments , in step S I , the multi-stage shaking table grading includes first shaking table grading and second shaking table grading in sequence . The step of the first shaking table grading is : the heavy ore in the chute is introduced into the first shaking table for first shaking table grading to obtain first shaking table light ore and first shaking table heavy ore . The step of the second shaking table grading is : the heavy ore in the first shaking table is introduced into the second shaking table for second shaking table grading to obtain second shaking table light ore , second shaking table medium ore and second shaking table heavy ore . the first shaking table light ore and the second shaking table light ore are both used as components of the mixed light ore in step S I for post-processing .

[0041] The mixed light ore material of the present invention includes chute light ore material , first shaking table light ore material and second shaking table light ore material . The chute light ore material still contains a small amount of chromium ore phase . Meanwhile , the first shaking table light ore material and the second shaking table light ore material also contain a small amount of chromium ore phase .

[0042] In some embodiments , in step S I , the steps of weak magnetic separation and spiral classi fication are : the heavy ore material of the second shaking table is introduced into the first weak magnetic separator for the first weak magnetic separation to obtain the first weak magnetic concentrate and the first weak magnetic selected ore , and the first weak magnetic concentrate is introduced into the first spiral classi fier for the first spiral classi fication to obtain the first chromium concentrate . The middle ore material of the second shaking table is introduced into the second weak magnetic separator for the second weak magnetic separation to obtain the second weak magnetic concentrate and the second weak magnetic selected ore , and the first weak magnetic selected ore and the second weak magnetic selected ore are introduced into the second spiral classi fier together for the second spiral classi fication to obtain the first chromium ore . The second weak magnetic selected ore is processed according to step S3 . In some embodiments , the speci fic operation of step S2 is : the mixed light ore is introduced into a ball mill stirring tank for ball milling and stirring, and then introduced into a second-stage cyclone for second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow is introduced into a third weak magnetic separator for third weak magnetic separation to obtain weak magnetic separation magnetic material and weak magnetic separation non-magnetic material , the weak magnetic separation magnetic material is subj ected to shaking table classi fication and spiral classi fication to obtain a second chromium concentrate , the weak magnetic separation non-magnetic material is introduced into a strong magnetic separator for strong magnetic separation to obtain strong magnetic separation non-magnetic material and strong magnetic separation magnetic material . The second-stage cyclone overflow and the strong magnetic separation non-magnetic material are processed according to step S3 .

[0043] In this embodiment , the purpose of performing strong magnetic separation on the weak magnetic separation non-magnetic material after weak magnetic separation is to reduce the interference of impurities in the strong magnetic separation non-magnetic material on chromium recovery .

[0044] In some embodiments , the speci fic operation of obtaining the second chromium concentrate by shaking table classi fication and spiral classi fication of weak magnetic separation magnetic materials is as follows : using a weak magnetic separation pump to sequentially transport the weak magnetic separation magnetic materials to a third shaking table and a third spiral classi fier for shaking table classi fication and spiral classi fication respectively, to obtain the second chromium concentrate .

[0045] In some embodiments , in step S2 , the magnetic field strength of the weak magnetic separation is 1000-2000 GS , and the magnetic field strength of the strong magnetic separation is 10000-20000 GS .

[0046] In this embodiment , the di f ferences in density and magnetic properties between chromite and other chromium-containing ore phases ( such as limonite , spinel , and silicate ) are utili zed to perform weak magnetic separation and then strong magnetic separation on the second-stage cyclone bottom flow , weak magnetic separation and strong magnetic separation are achieved by setting di f ferent magnetic field intensities . In some embodiments , in step S3 , the strong magnetic separation magnetic material and the second weak magnetic separation ore are mixed and put into a ball mill for ball milling, and then returned to the ball mill stirring tank in step S2 to continue the ball milling and stirring process .

[0047] In this embodiment , the strong magnetic separation magnetic material containing chromium and the second weak magnetic separation ore are mixed and ball-milled and then recycled to the ball mill stirring tank, which is beneficial to further enrichment and separation of chromium .

[0048] In some embodiments , in step S3 , the speci fic steps for preparing the high-pressure leaching stock solution are as follows : the overflow of the first cyclone is conveyed to the finished product tank after passing through a first impurity removal screen for impurities removal , and then conveyed to the raw ore slurry storage tank , the overflow of the second cyclone is mixed with the strong magnetic separation non-magnetic material , and then conveyed to the raw ore slurry storage tank after passing through a second impurity removal screen for impurities removal . The mixture in the raw ore slurry storage tank is introduced into a thickener containing a flocculant for solid-liquid separation to obtain the high-pressure leaching stock solution .

[0049] It is worth noting that the first shaker in the present invention is a single-stage shaker, and the second and third shakers are both two-stage shakers . The single-stage shaker and the two-stage shaker both belong to the conventional setting methods of shakers in this field, and they can respectively adopt the corresponding conventional shaker parameters in this field to achieve the sorting purpose of this invention .

[0050] The present solution is further described below through speci fic embodiments .

[0051] Embodiment 1

[0052] A combined beneficiation method for laterite nickel ore comprises the following steps :

[0053] S I . The raw laterite nickel ore is transported to the drum ore washer by heavy-duty plate feeder to remove gravel with a particle si ze of >35 mm, and then processed by double spiral scrubber and linear vibrating screen to remove gravel with a particle si ze of >2 mm, and then sequentially input into the mixing tank and slurry pump to obtain the gravel- free ore (washed ore ) . After determination, the Cr20s in the gravel- free ore grade is 3 . 39% , and the recovery rate is 97 . 4 % . The raw ore after the gravel is removed is introduced into a first cyclone for a first cyclone separation to obtain a cyclone overflow and a cyclone underflow . The first cyclone underflow is merged into a spiral chute to obtain a chute light ore material and a chute heavy ore material . The chute heavy ore material is merged into a first shaking table for a first shaking table classi fication to obtain a first shaking table light ore material and a first shaking table heavy ore material . The first shaking table heavy ore material is merged into a second shaking table for a second shaking table classi fication to obtain a second shaking table light ore material , a second shaking table medium ore material , and a second shaking table heavy ore material . The second shaking table heavy ore material is merged into a first weak magnetic separator for a first weak magnetic separation to obtain a first weak magnetic separation concentrate and a first weak magnetic separation medium ore . The first weak magnetic separation concentrate is merged into a first spiral classi fier for a first spiral classi fication to obtain a first chrome concentrate , the first chrome concentrate Cr2Os grade is 40 . 48 % , and the recovery rate is 10 . 67 % . The second shaking table middlings are fed into the second weak magnetic separator for the second weak magnetic separation to obtain the second weak magnetic concentrate and the second weak magnetic middlings . The first weak magnetic middlings and the second weak magnetic concentrate are fed into the second spiral classi fier for the second spiral classi fication to obtain the first chromium middlings , and the first chromium middlings have a Cr2Os grade of 24 . 72 % and a recovery rate of 10 . 36% . The chute light ore , the first shaking table light ore and the second shaking table light ore are mixed to obtain the mixed light ore .

[0054] S2 . The mixed light ore is introduced into a ball mill stirring tank for ball milling and stirring, and then introduced into a second-stage cyclone for second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow is introduced into a third weak magnetic separator for third weak magnetic separation to obtain weak magnetic separation magnetic materials and weak magnetic separation non-magnetic materials , and the weak magnetic separation magnetic materials are respectively transported to a third shaking table and a third spiral classi fier by a weak magnetic separation pump for shaking table classi fication and spiral classi fication to obtain a second chromium concentrate , and the weak magnetic separation non-magnetic materials are introduced into a strong magnetic separator for strong magnetic separation to obtain strong magnetic separation non-magnetic materials and strong magnetic separation magnetic materials . Wherein, the magnetic field strength of the weak magnetic separation is 1500 GS , and the magnetic field strength of the strong magnetic separation is 10000 GS .

[0055] S3 . Mix the magnetic material from the strong magnetic separation and the ore from the second weak magnetic separation and feed them into the ball mill for ball milling, then return them to the ball mill stirring tank for further bal l milling and stirring treatment , the overflow from the first cyclone is screened for impurities removal and then transported to the finished product tank and then to the raw ore slurry storage tank . The overflow from the second cyclone is mixed with the non-magnetic material from the strong magnetic separation and then screened for impurities removal and then transported to the raw ore slurry storage tank . The mixture in the raw ore slurry storage tank is fed into a thickener containing a flocculant for solid-liquid separation to obtain the high-pressure leaching stock solution . the Cr2Os grade and recovery rate in the second chromium concentrate remain stable , the laterite nickel ore combined beneficiation process of this embodiment is completed , the Cr20s grade of the second chromium concentrate obtained in this embodiment is 37 . 23% , and the recovery rate is 15 . 36% . The chromium content of the high-pressure leaching stock solution is 0 . 01 % .

[0056] Comparative Example 1

[0057] A combined beneficiation method for laterite nickel ore , the other contents of which are the same as those of Example 1 , except that step S3 does not include mixing the strong magnetic separation magnetic material with the second weak magnetic separation ore and ball milling and recycling them to the ball mill stirring tank, that is , the strong magnetic separation magnetic material and the second weak magnetic separation ore in step S3 are used as slag instead of ball milling and recycling . Cr20s grade and recovery rate in the second chromium concentrate remain stable , the laterite nickel ore combined beneficiation process of this comparative example is completed . The Cr20s grade of the second chromium concentrate obtained in this comparative example is 32 . 62 % , and the recovery rate is 4 . 93% . The chromium content of the high-pressure leaching stock solution is 0 . 05% .

[0058] Comparative Example 2

[0059] A combined beneficiation method for laterite nickel ore , the other contents are the same as those in Example 1 , except that the speci fic steps of step S2 and step S3 are :

[0060] S2 . The mixed light ore is introduced into a ball mill stirring tank for ball milling and stirring, and then introduced into a second-stage cyclone for second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow is introduced into a third weak magnetic separator for third weak magnetic separation to obtain weak magnetic separation magnetic materials and weak magnetic separation non-magnetic materials , and the weak magnetic separation magnetic materials are sequentially transported to a third shaking table and a third spiral classi fier by a weak magnetic separation pump for shaking table classi fication and spiral classi fication respectively to obtain a second chromium concentrate . The first-stage cyclone overflow is transported to a finished product tank after a first-stage impurity removal screen and then to a raw ore slurry storage tank, the second-stage cyclone overflow is mixed with the weak magnetic separation non-magnetic materials , and then transported to a raw ore slurry storage tank after a second-stage impurity removal screen and second-stage impurity removal . The mixture in the raw ore slurry storage tank is introduced into a thickener containing a flocculant for solid-liquid separation to obtain a high-pressure leaching stock solution .

[0061] The second chromium concentrate obtained in this comparative example has a Cr20s grade of 33 . 98 % and a recovery rate of 8 . 83% . The chromium content of the high-pressure leaching solution is 0 . 04 % .

[0062] Comparative Example 3

[0063] A combined beneficiation method for laterite nickel ore , the other contents of which are the same as those of Example 1 , except that the weak magnetic separation and strong magnetic separation processes after the second-stage cyclone separation are adj usted to after the first-stage cyclone separation, and the speci fic steps are as follows :

[0064] 51 . The raw laterite nickel ore is transported to the drum ore washer by heavy-duty plate feeder to remove gravel with a particle si ze of >35 mm, and then processed by double spiral scrubber and linear vibrating screen to remove gravel with a particle si ze of >2 mm, and then sequentially input into the mixing tank and slurry pump to obtain the gravel- free ore (washed ore ) . After determination, the Cr 2 0 in the gravel- free ore the grade of 3 is 3 . 39% and the recovery rate is 97 . 4 % . The raw ore after the gravel is removed is introduced into a cyclone for a cyclone separation to obtain a cyclone overflow and a cyclone underflow . The cyclone underflow is introduced into the third weak magnetic separator for weak magnetic separation to obtain weak magnetic materials and weak magnetic non-magnetic materials . The weak magnetic materials are introduced into the weak magnetic machine pump pool and then classi fied by the third spiral classi fier to obtain the second chromium middling ore . The weak magnetic non-magnetic materials are introduced into the strong magnetic separator for strong magnetic separation to obtain strong magnetic non-magnetic materials and strong magnetic materials . Among them, the magnetic field strength of the first weak magnetic separation is 1500 GS . The magnetic field strength of the strong magnetic separation is 10000 GS .

[0065] 52 . The strong magnetic separation magnetic materials are introduced into the spiral chute to obtain the light ore material and the heavy ore material of the chute , the heavy ore material of the chute is introduced into the f irst shaking table for the first shaking table classi fication to obtain the light ore material and the heavy ore material of the first shaking table . The heavy ore material of the first shaking table is introduced into the second shaking table for the second shaking table classi fication to obtain the light ore material of the second shaking table , the medium ore material of the second shaking table , and the heavy ore material of the second shaking table . The heavy ore material of the second shaking table is introduced into the first weak magnetic separator for the first weak magnetic separation to obtain the first weak magnetic separation concentrate and the first weak magnetic separation medium, and the first weak magnetic separation concentrate is introduced into the first spiral classi fier for the first spiral classi fication to obtain the first chrome concentrate . The Cr2Os grade of the first chrome concentrate is determined to be 37 . 38 % , and the recovery rate is 15 . 44 % The second shaking table medium ore is fed into the second weak magnetic separator for second weak magnetic separation to obtain second weak magnetic concentrate and second weak magnetic medium ore . The second weak magnetic concentrate and the first weak magnetic medium ore are fed into the second spiral classi fier for second spiral classi fication to obtain the first chromium medium ore . the first chromium medium ore Cr2Os grade is determined to be 21 . 01 % and the recovery rate is 8 . 93% . the chute light ore , the first shaking table light ore and the second shaking table light ore are mixed to obtain a mixed light ore .

[0066] S3 . The light ore material in the chute , the light ore material in the first shaking table and the light ore material in the second shaking table are mixed with the strong magnetic separation non-magnetic material as mixed light ore material and then introduced into a ball mill stirring tank for ball milling and stirring, and then introduced into a two-stage cyclone separator for two-stage cyclone separation to obtain a two-stage cyclone underflow and a two-stage cyclone overflow . The overflow of the first stage cyclone is passed through a first-stage impurity removal screen for one-stage impurity removal and then transported to a finished product tank and then to a raw ore slurry storage tank . The overflow of the second stage cyclone is passed through a second-stage impurity removal screen for two-stage impurity removal and then transported to a raw ore slurry storage tank . The mixture in the raw ore slurry storage tank is introduced into a thickener containing a flocculant for solid-liquid separation to obtain a high-pressure leaching stock solution . The chromium content of the high-pressure leaching stock solution is measured to be 0 . 03% .

[0067] The above embodiments and comparative examples illustrate that the present invention separates chromite from laterite nickel ore through a combined process of multi-stage magnetic separation, spiral chute , multi-stage shaking table classi fication, and multi-stage cyclone separation, and the recovery rates of the obtained chromium concentrate and chromium middling' s are high, the recovery rate of the chromium concentrate is 20-30% , and the grade of the chromium concentrate is 37-42 % . The present invention is beneficial to reducing the chromium removal pressure in the hydrometallurgical process of laterite nickel ore , and is beneficial to the comprehensive utili zation of the chromium element .

[0068] The above are only preferred speci fic implementations of the present invention, but the protection scope of the present invention is not limited thereto . Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention .

Claims

Claims1 . A combined beneficiation method for laterite nickel ore , characteri zed in that it comprises the following steps :S I . The raw ore is sequentially subj ected to a washing process and a cyclone separation to obtain a cyclone overflow and a cyclone underflow . The cyclone underflow is sequentially subj ected to spiral chute classi fication, multi-stage shaking table classi fication, and then weak magnetic separation and spiral classi fication to obtain a first chromium concentrate , a first chromium middling, a second weak magnetic separation middling and a mixed light ore .S2 . After the mixed light ore is subj ected to ball mill stirring treatment , two-stage cyclone separation is performed to obtain a second-stage cyclone underflow and a second-stage cyclone overflow , the second-stage cyclone underflow is subj ected to weak magnetic separation to obtain a weak magnetic separation magnetic material and a weak magnetic separation non-magnetic material , the weak magnetic separation magnetic material is subj ected to shaking table classi fication and spiral classi fication to obtain a second chrome concentrate , and the weak magnetic separation non-magnetic material is subj ected to strong magnetic separation to obtain a strong magnetic separation non-magnetic material and a strong magnetic separation magnetic material .S3 . The strong magnetic separation magnetic material and the second weak magnetic separation ore are mixed and ball-milled and then reused in the ball milling and stirring process described in step S2 , and the first-stage cyclone overflow, the second-stage cyclone overflow and the strong magnetic separation non-magnetic material are mixed and used to prepare high-pressure leaching stock solution .2 . Laterite nickel ore according to claim 1 is characteri zed in that , in step S I , the speci fic step of the one-stage cyclone separation is : introducing the raw ore into a cyclone after the ore washing process for a one-stage cyclone separation to obtain a one-stage cyclone overflow and a one-stage cyclone underflow, and the one-stage cyclone overflow is processed according to step S3 .3 . The combined beneficiation method of laterite nickel ore according to claim 1 is characteri zed in that , in step S I , the speci fic operation of the spiral chute classi fication is : the first section of the cyclone underflow is merged into the spiral chute to obtain a chute light ore material and a chute heavy ore material , the chute light ore material is post-processed as a component of the mixed light ore material described in step S I .4 . The combined beneficiation method of laterite nickel ore according to claim 3 , characteri zed in that , in step S I , the multi-stage shaking table classi fication includes a first shaking table classi fication and a second shaking table classi fication in sequence .The first shaking table classi fication step comprises : the heavy ore material in the chute is introduced into the first shaking table for first shaking table classi fication to obtain the first shaking table light ore material and the first shaking table heavy ore material .The second shaking table classi fication step comprises : trans ferring the heavy ore from the first shaking table to the second shaking table for second shaking table classi fication to obtain light ore from the second shaking table , medium ore from the second shaking table , and heavy ore from the second shaking table .The first shaking table light ore material and the second shaking table light ore material are both used as components of the mixed light ore material in step S I for post-processing .5 . The combined beneficiation method of laterite nickel ore according to claim 4 is characteri zed in that in step S I , the steps of weak magnetic separation and spiral classi fication are : the second shaking table heavy ore material is introduced into the first weak magnetic separator for first weak magnetic separation to obtain a first weak magnetic concentrate and a first weak magnetic selected ore , the first weak magnetic concentrate is introduced into the first spiral classi fier for first spiral classi fication to obtain a first chromium concentrate . The second shaking table medium ore material is introduced into the second weak magnetic separator for second weak magnetic separation to obtain a second weak magnetic concentrate anda second weak magnetic selected ore , the first weak magnetic selected ore and the second weak magnetic selected ore are introduced into the second spiral classi fier for second spiral classi fication to obtain a first chromium medium ore . the second weak magnetic selected ore is processed according to step S3 .6 . The combined beneficiation method of laterite nickel ore according to claim 1 , characteri zed in that the speci fic operation of step S2 is : after the mixed light ore is introduced into a ball mill stirring tank for ball milling and stirring treatment , it is introduced into a second-stage cyclone for second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow is introduced into a third weak magnetic separator for third weak magnetic separation to obtain weak magnetic separation magnetic material and weak magnetic separation non-magnetic material , the weak magnetic separation magnetic material is subj ected to shaking table classi fication and spiral classi fication to obtain a second chrome concentrate , the weak magnetic separation non-magnetic material is introduced into a strong magnetic separator for strong magnetic separation to obtain strong magnetic separation non-magnetic material and strong magnetic separation magnetic material . The second-stage cyclone overflow and strong magnetic separation non-magnetic material are processed according to step S3 .7 . The combined beneficiation method of laterite-nickel ore according to claim 6 is characteri zed in that the speci fic operation of obtaining the second chromium concentrate by subj ecting the weak magnetic separation magnetic material to shaking table classi fication and spiral classi fication is : using a weak magnetic separation pump to sequentially transport the weak magnetic separation magnetic material to a third shaking table and a third spiral classi fier for shaking table classi fication and spiral classi fication respectively, to obtain the second chromium concentrate .8 . The combined beneficiation method of laterite nickel ore according to claim 1 , characteri zed in that , in step S2 , the magnetic fieldstrength of the weak magnetic separation is 1000-2000 GS , and the magnetic field strength of the strong magnetic separation is 10000-20000 GS .9 . The combined beneficiation method of laterite nickel ore according to claim 6 , characteri zed in that , in step S3 , the strong magnetic separation magnetic material and the second weak magnetic separation ore are mixed and introduced into a ball mill for ball milling, and then returned to the ball mill stirring tank described in step S2 for further ball milling and stirring treatment .10 . The combined beneficiation method of laterite nickel ore according to claim 1 is characteri zed in that in step S3 , the speci fic steps of preparing the high-pressure leaching stock solution are : the overflow of the first stage cyclone is transported to the finished product tank after being screened for one stage of impurities removal , and then transported to the raw ore slurry storage tank , the overflow of the second stage cyclone is mixed with the strong magnetic separation non-magnetic material , and then transported to the raw ore slurry storage tank after being screened for two stages of impurities removal . The mixture in the raw ore slurry storage tank is introduced into a thickener containing a flocculant for solid-liquid separation to obtain the high-pressure leaching stock solution .

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