A method for cyclic chromium processing

Abstract

The invention discloses a method for cyclic chromium processing, which includes: the raw ore is subjected to a washing process and a first-stage cyclone separation in sequence to obtain the first-stage cyclone overflow and the first-stage cyclone underflow. The first-stage cyclone underflow is subjected to weak magnetic separation treatment to obtain the first chrome middlings. The first-stage cyclone underflow is subjected to weak magnetic separation and strong magnetic separation treatment in sequence to obtain the strong magnetically separated non-magnetic material and the strong magnetically separated magnetic material; The strong magnetically separated magnetic material are sequentially subjected to spiral chute classification, multi-stages shaking table classification, and then weak magnetic separation and spiral classification to obtain chrome concentrate, second chrome middlings, second weak magnetically separated middlings and mixed light ore; After the mixed light ore and the strong magnetically separated non-magnetic material are mixed and ball-milled, the second stage of cyclone separation is carried out. The obtained second-stage cyclone underflow and the second-stage weak magnetic separation ore are ball-milled and then returned to the strong magnetic separation process. The invention separates the chromite in the laterite nickel ore through the combined process of multi-stage magnetic separation, spiral chute, multi-stages shaking table classification and multi-stage cyclone separation, so as to improve the recovery rate and grade of the obtained chrome concentrate.

Description

[0001] Description

[0002] A METHOD FOR CYCLIC CHROMIUM PROCESSING

[0003] Filed Of Disclosure

[0004] The invention relates to the technical field of mineral processing, and in particular to a method for cyclic chromium processing

[0005] Background

[0006] At present , hydrosmelting of laterite nickel ore through high-pressure acid leaching process has very broad prospects in the new energy industry . However, high-pressure acid leaching requires expensive corrosion-resistant equipment . The spinel-type chromite associated with laterite nickel ore has a strong abrasive ef fect on the anti-corrosion layer of the hydrosmelting equipment , which not only increases the equipment cost of laterite nickel ore hydrosmelting but also poses a safety risk . At the same time , after high-pressure acid leaching, it is also necessary to remove impurities such as iron, aluminum, and chromium to ensure the grade of the product after laterite nickel ore hydrosmelting .

[0007] In order to reduce the negative impact of chromite in the hydrometallurgical smelting of laterite nickel ore , it is necessary to separate and remove chromite from laterite nickel ore . At the same time , some quali fied chrome concentrate can be obtained in the beneficiation steps to achieve comprehensive utili zation of resources . For the separation of chromite in laterite nickel ore , the existing technology generally adopts a single gravity separation or magnetic separation method . However, a single separation method often loses a large part of chromium, and the obtained chrome concentrate grade is also relatively low .

[0008] Therefore , it is necessary to provide a cyclic chromium separation method for improving the grade and recovery rate of chrome concentrate .

[0009] Summary In view of this , this application provides a cyclic chromium separation method to solve the problem of how to improve the grade and recovery rate of chrome concentrate during the laterite nickel ore beneficiation process .

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

[0011] This application provides a cyclic chromium separation method, including :

[0012] S I . The raw ore is subj ected to a washing process and a first-stage cyclone separation in sequence to obtain a first-stage cyclone overflow and a first-stage cyclone underflow . The first-stage cyclone underflow is subj ected to weak magnetic separation treatment to obtain a first-stage chromite middling product . The first-stage cyclone underflow is subj ected to weak magnetic separation and strong magnetic separation treatment in sequence to obtain the non-magnetic material after strong magnetic separation and the magnetic material after strong magnetic separation .

[0013] 52 . The magnetic materials after strong magnetic separation are sequentially subj ected to spiral chute separation, multi-stages shaking table separation, and then weak magnetic separation and spiral classi fication to obtain chrome concentrate , second-stage chromite middling product , second weak magnetic separation middlings and mixed light ore .

[0014] 53 . After mixing the mixed light ore with the non-magnetic material after strong magnetic separation, the second-stage cyclone separation is carried out , and the second-stage cyclone overflow is mixed with the first-stage cyclone overflow and used to prepare the raw solution for high-pressure leaching . The second-stage cyclone underflow and the second-stage weak magnetic separation ore are mixed and ball-milled and then returned to the strong magnetic separation process in step S I .

[0015] Preferably, in step S I , the magnetic field strength of the weak magnetic separation is 1000-2000 GS ; the magnetic field strength of the strong magnetic separation is 10000-20000 GS .

[0016] Preferably, in step S I , the speci fic steps of the first-stage cyclone separation include : introducing the raw ore into a first-stage cyclone after the ore washing process for first-stage cyclone separation to obtain a first-stage cyclone overflow and a first-stage cyclone underflow, and the first-stage cyclone overflow is processed according to step S3 .

[0017] Preferably, in step S I , the speci fic steps of weak magnetic separation are : the first-stage cyclone bottom flow is introduced into the first weak magnetic separator for the first weak magnetic separation to obtain weak magnetically separated magnetic material and weak magnetically separated non-magnetic material , the weak magnetically separated magnetic material is introduced into storage tank for weak magnetic machine and then classi fied by the spiral classi fier to obtain the first chrome middlings .

[0018] Preferably, in step S I , the speci fic steps of strong magnetic separation are : introducing weak magnetically separated non-magnetic materials into a strong magnetic separator for strong magnetic separation to obtain strong magnetically separated non-magnetic materials and strong magnetically separated magnetic materials , and processing the strong magnetically separated non-magnetic materials according to step S3 .

[0019] Preferably, in step S2 , the speci fic steps of spiral chute classi fication are : the strong magnetically separated magnetic materials is introduced into the spiral chute to obtain chute light ore and chute heavy ore , and the chute light ore is used as a component of the mixed light ore in step S3 for post-processing .

[0020] Preferably, in step S2 , the multi-stage shaking table classi fication includes the first stage shaking table classi fication and the second stage shaking table classi fication in sequence ; the steps of the first stage shaking table classi fication are : The chute heavy ore is fed into the first-stage shaking table for classi fication, and then the first-stage shaking table light ore and the first-stage shaking table heavy ore are obtained . The steps of the second-stage shaking table classi fication are : the first-stage shaking table heavy ore is introduced into the second-stage shaking table for second-stage shaking table classi fication to obtain the second-stage shaking table light ore , the second-stage shaking table medium ore and the second-stage shaking table heavy ore ; the first-stage shaking table light ore and second-stage shaking table light ore are both used as components of the mixed light ore in step S3 for post-processing .

[0021] Preferably, in step S2 , the steps of weak magnetic separation and spiral classi fication are : The second-stage shaking table heavy ore is fed into the second-stage weak magnetic separator for second-stage weak magnetic separation to obtain the first weak magnetically separated concentrate and the first weak magnetically separated middlings . The first weak magnetically separated concentrate is fed into the first-stage spiral classi fier for the first-stage spiral classi fication to obtain chrome concentrate . The second-stage shaking table medium ore is fed into the third-stage weak magnetic separator for third-stage weak magnetic separation to obtain the second weak magnetically separated concentrate and the second weak magnetically separated middlings .

[0022] Preferably, in step S3 , the mixed light ore and the strong magnetically separated non-magnetic material are mixed and then introduced into a ball mill stirring tank for ball milling and stirring, and then introduced into a second-stage cyclone separator for second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow, and the second-stage cyclone underflow and the second weak magnetically separated middlings are introduced into a ball mill for ball milling and then returned to the strong magnetic separator to continue the strong magnetic separation process .

[0023] Preferably, in step S3 , the speci fic steps of preparing the high-pressure leaching stock solution are : The first-stage cyclone overflow is transported to the finished product tank after the first-stage impurity removal through the first-stage impurity removal screen, and then transported to the raw ore slurry storage tank . The second-stage cyclone overflow is transported to the raw ore slurry storage tank after the second-stage impurity removal screen . The mixture in the raw ore slurry storage tank is fed into a thickener containing flocculants to separate the solid and liquid to obtain the high-pressure leaching stock solution .

[0024] The beneficial ef fects of the present application are as follows : the present application separates the chromite in the laterite nickel ore through a integrated method of multi-stage magnetic separation, spiral chute , multi-stage shaking table classi fication, and multi-stage cyclone separation, and the recovery rate of the obtained chrome concentrate and chrome middlings is high, and the grade of the chrome concentrate is high (higher than or equal to 36% ) , which is beneficial to reducing the chromium removal pressure in the hydrosmelting process of laterite nickel ore and is beneficial to the comprehensive utili zation of the chromium element .

[0025] Brief Description Of The Drawings

[0026] FIG . l is a process flow diagram of the present application .

[0027] Detailed Description Of Preferred Embodiments

[0028] In order to clari fy the purpose , technical solutions and advantages of the present invention, the present invention is further described in detail below in conj unction with embodiments . It should be understood that the speci fic embodiments described herein are only used to explain the present invention and are not intended to limit the present invention .

[0029] The embodiments and control examples of the present application 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 SiO2 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 application is to separate chromite from di f ferent mineral phases and improve the grade of chrome concentrate , so as to improve the comprehensive utili zation rate of laterite nickel ore .

[0030] Based on this , the present invention was created .

[0031] The present application provides a cyclic chromium separation process , including :

[0032] S I . The raw ore is subj ected to a washing process and a first-stage cyclone separation in sequence to obtain a first-stage cyclone overflow and a first-stage cyclone underflow . The first-stage cyclone underflow is subj ected to weak magnetic separation treatment to obtain a first-stage chromite middling product . The first-stage cyclone underflow is subj ected to weak magnetic separation and strong magnetic separation treatment in sequence to obtain the non-magnetic material after strong magnetic separation and the magnetic material after strong magnetic separation .

[0033] S2 . The magnetic materials after strong magnetic separation are sequentially subj ected to spiral chute separation, multi-stages shaking table separation, and then weak magnetic separation and spiral classi fication to obtain the chrome concentrate , the second chrome middlings , second weak magnetically separated middlings and mixed light ore .

[0034] S3 . After mixing the mixed light ore with the non-magnetic material after strong magnetic separation, the second-stage cyclone separation is carried out , and the second-stage cyclone overflow is mixed with the first-stage cyclone overflow and used to prepare the stock solution for high-pressure leaching . The second-stage cyclone underflow and the second-stage weak magnetic separation ore are mixed and ball-milled and then returned to the strong magnetic separation process in step S I .

[0035] The principle of the present method is that the weak magnetic separation and strong magnetic separation is performed sequentially on the first-stage cyclone bottom flow before step S2 . Firstly, weak magnetic separation is used to recover the first-stage chromite middling product , and then strong magnetic separation is used to further improve the grade of chromite . This integrated method can not only improve the recovery rate of chrome concentrate , but also screen out more chromium middlings , signi ficantly reduce the chromium content in the subsequent high-pressure leaching solution, and reduce the amount of chromium removed from the high-pressure leaching solution . In addition, it was found that one of the reasons for the low recovery rate and grade of chromite is that the mixed light ore and the non-magnetic material after strong magnetic separation still contain chromite buried in the chromite . Therefore , in the present application, the second-stage cyclone bottom flow and the second-stage weak magnetic separation ore are returned to the strong magnetic separation process in step S I after ball milling . The ball milling process improves the monomer dissociation degree of chromite encapsulated in limonite , so that the encapsulated chromite is separated and subj ected to strong magnetic separation again, which is beneficial to the subsequent separation and recovery of chromium, and further improves the recovery rate of chrome concentrate .

[0036] In some embodiments , in step S I , the speci fic steps of ore washing include : using a heavy-duty plate feeder to transport the laterite nickel ore to a drum ore washing machine to remove gravel with a particle si ze of 0 . 07- 0 . 09 mm, and then removing gravel with a particle size of 0.02-0.04 mm through a twin-screw scrubber and a linear vibrating screen to obtain gravel-free ore.

[0037] In this embodiment, gravel is first removed from the raw ore to reduce the interference of gravel in subsequent mineral processing.

[0038] In some embodiments, in step SI, the magnetic field strength of the weak magnetic separation is 1000-2000 GS; the magnetic field strength of the strong magnetic separation is 10000-20000 GS

[0039] In this embodiment, the difference in density and magnetic properties between chromite and other chromium-containing ore phases (such as limonite, spinel, and silicate) is used to perform weak magnetic separation and then strong magnetic separation on the first-stage cyclone bottom flow. By setting different magnetic field strengths, weak magnetic separation and strong magnetic separation can be achieved respectively.

[0040] In some embodiments, in step SI, the specific steps of the first-stage cyclone separation include: The raw ore is introduced into the first-stage cyclone after the ore washing process for first-stage cyclone separation to obtain first-stage cyclone overflow and first-stage cyclone underflow. The first-stage cyclone overflow is processed according to step S3.

[0041] In this embodiment, the washed ore is separated into the first-stage cyclone overflow and the first-stage cyclone underflow after the first-stage cyclone separation. Since the grades of Ni and Cr2Os do not change synchronously with the particle size, most of the chromium-containing impurities are separated in the first-stage cyclone underflow.

[0042] In some embodiments, in step SI, the specific steps of weak magnetic separation are: The first-stage cyclone underflow is fed into the first-stage weak magnetic separator for the first-stage weak magnetic separation. Magnetic materials after weak magnetic separation and non-magnetic materials after weak magnetic separation are obtained. The magnetic materials after weak magnetic separation are added to the ore storage tank for weak magnetic machine and then classified by the spiral classifier to obtain the first chrome middlings.

[0043] In some embodiments, in step SI, the specific steps of strong magnetic separation are: introducing weak magnetically separated non-magnetic materials into a strong magnetic separator for strong magnetic separation to obtain strong magnetically separated non-magnetic materials and strong magnetically separated magnetic materials , and processing the strong magnetically separated non-magnetic materials according to step S3 .

[0044] In this embodiment , weak magnetic separation is first used to recover the first-stage chromite middlings , and then strong magnetic separation is used to further improve the grade of the chromite . This combined process can not only improve the recovery rate of the chrome concentrate , but also screen out more chromite middlings , signi ficantly reduce the chromium content in the subsequent high-pressure leaching solution, and reduce the amount of chromium removed from the high-pressure leaching solution .

[0045] In some embodiments , in step S2 , the speci fic steps of spiral chute classi fication are : the strong magnetically separated magnetic material is introduced into the spiral chute to obtain chute light ore and chute heavy ore , and the chute light ore is post-processed as part of the mixed light ore in step S3 .

[0046] In this embodiment , the obtained light ore material in the chute is introduced into a ball mill tank and then subj ected to a two-stage cyclone separation; the obtained heavy ore material in the chute contains both valuable metals and a chromium-containing ore phase .

[0047] In some embodiments , in step S2 , the multi-stage shaking table classi fication includes a first-stage shaking table classi fication and a second-stage shaking table classi fication in sequence ; The steps of the first-stage shaking table classi fication are : the chute heavy ore is introduced into the first-stage shaking table for first-stage shaking table classi fication to obtain the first-stage shaking table light ore and the first-stage shaking table heavy ore ; The steps of the second-stage shaking table classi fication are as follows : the first-stage shaking table heavy ore is introduced into the second-stage shaking table for second-stage shaking table classi fication to obtain the second-stage shaking table light ore , second-stage shaking table medium ore , and the second-stage shaking table heavy ore ; first-stage shaking table light ore and second-stage shaking table light ore are both used as the composition of the mixed light ore material in step S3 for post-processing .

[0048] In some embodiments , in step S2 , the steps of weak magnetic separation and spiral classi fication are : The second-stage shaking table heavy ore is fed into the second-stage weak magnetic separator for second-stage weak magnetic separation to obtain the first weak magnetically separated concentrate and the first weak magnetically separated middl ings . The first weak magnetically separated concentrate is fed into the first spiral classi fier for first spiral classi fication to obtain chrome concentrate ; The second-stage shaking table medium ore is fed into the third-stage weak magnetic separator for third-stage weak magnetic separation to obtain the second weak magnetically separated concentrate and the second weak magnetically separated middlings . The second weak magnetically separated middlings is ball-milled and then returned to the strong magnetic separation process for further strong magnetic separation . The second weak magnetically separated concentrate and the first weak magnetically separated middlings are introduced into the second-stage spiral classi fier for the second-stage spiral classi fication process to obtain the second chrome middlings .

[0049] In some embodiments , in step S3 , the mixed light ore and the strong magnetically separated non-magnetic material are mixed and then introduced into a ball mill stirring tank for ball milling and stirring, and then introduced into a second-stage cyclone separator for a second-stage cyclone separation to obtain a second-stage cyclone underflow and a second-stage cyclone overflow . The second-stage cyclone underflow and the second weak magnetically separated ore are introduced into a ball mill for ball milling and then returned into the strong magnetic separator to continue the strong magnetic separation process .

[0050] In some embodiments , the mixed light ore includes chute light ore , first-stage shaking table light ore and second-stage shaking table light ore .

[0051] Preferably, in step S3 , the speci fic steps of preparing the high-pressure leaching stock solution are : The first-stage cyclone overflow is transported to the finished product tank after the first-stage impurity removal through the first-stage impurity removal screen, and then transported to the raw ore slurry storage tank . The second-stage cyclone overflow is transported to the raw ore slurry storage tank after the second-stage impurity removal screen . The mixture in the raw ore slurry storage tank is fed into a thickener containing flocculants to separate the solid and liquid to obtain the high-pressure leaching stock solution . The present technical solution is further described below through speci fic embodiments .

[0052] Embodiment 1

[0053] A cyclic chromium selection process comprises the following steps :

[0054] 51 . Use a heavy-duty plate feeder to transport the laterite nickel ore to a drum ore washing machine to remove gravel with a particle si ze > 35 mm, and then removing gravel with a particle si ze of 1 2 mm through a twin-screw scrubber and a linear vibrating screen, and then sequentially input into the mixing tank and slurry pump to obtain gravel- free ore (washed ore ) . The Cr20s content in the gravel ore is 3 . 21 % and the recovery rate is 59 . 73% ; The raw ore after the gravel is removed is introduced into the first-stage cyclone for first-stage cyclone separation to obtain the first-stage cyclone overflow and the first-stage cyclone underflow; The first-stage cyclone bottom flow is fed into the first-stage weak magnetic separator for the first-stage weak magnetic separation to obtain weak magnetically separated magnetic materials and weak magnetically separated non-magnetic materials . The weak magnetically separated magnetic materials are added to the ore storage tank for weak magnetic machine and then classi fied by the spiral classi fier to obtain the first chromite middlings . The Cr2Os grade of the first chromite middlings ore was determined to be 17 . 6% and the recovery rate was 30 . 2 % . The weak magnetically separated non-magnetic material was fed to the strong magnetic separator for strong magnetic separation to obtain strong magnetically separated non-magnetic material and strong magnetically separated magnetic material . The magnetic field strength of the first weak magnetic separation was 1500 GS ; the magnetic field strength of the strong magnetic separation was 10000 GS .

[0055] 52 . The strong magnetically separated magnetic material is introduced into the spiral chute to obtain chute light ore and chute heavy ore ; The chute heavy ore is introduced into the first-stage shaking table for first-stage shaking table classi fication to obtain the first-stage shaking table light ore and the first-stage shaking table heavy ore ; The first-stage shaking table heavy ore is introduced into the second-stage shaking table for second-stage shaking table classi fication to obtain the second-stage shaking table light ore , second-stage shaking table medium ore , and the second-stage shaking table heavy ore ; The second-stage shaking table heavy ore is fed into the second-stage weak magnetic separator for second-stage weak magnetic separation to obtain the first weak magnetically separated concentrate and the first weak magnetically separated middlings . The first weak magnetically separated concentrate is fed into the first spiral classi fier for the first spiral classi fication to obtain chrome concentrate . The Cr2Os grade of chrome concentrate was determined to be 38 . 06% and the recovery rate was 19 . 86% ; The second-stage shaking table medium ore is fed into the third-stage weak magnetic separator for third-stage weak magnetic separation to obtain the second weak magnetically separated concentrate and the second weak magnetically separated middlings . The second weak magnetically separated concentrate and the first weak magnetically separated middlings are fed into the second-stage spiral classi fier for the second-stage spiral classi fication process to obtain the second chrome middlings . The Cr2Os grade of the second chrome middlings was determined to be 26 . 1 % , and the recovery rate was 8 . 3% ; The magnetic field strength of the second-stage weak magnetic separation was 1300 GS , and the magnetic field strength of the third-stage weak magnetic separation was 1200 GS .

[0056] S3 . The chute light ore , the first-stage shaking table light ore and the second-stage shaking table light ore are mixed with the strong magnetically separated non-magnetic material and then introduced into the ball mill stirring tank for ball milling and stirring, and then introduced into the second-stage cyclone separator for second-stage cyclone separation to obtain the second-stage cyclone underflow and the second-stage cyclone overflow . The second-stage cyclone bottom flow and the second weak magnetically separated middlings are fed into the ball mill for ball milling and then returned to the strong magnetic separator for the strong magnetic separation process ; The first-stage cyclone overflow is sent to the finished product tank after being de-impuri f led by the first-stage impurity removal screen, and then to the raw ore slurry storage tank . The second-stage cyclone overflow is sent to the raw ore s lurry storage tank after being de-impuri f led by the second-stage impurity removal screen . The mixture in the raw ore slurry storage tank is trans ferred to 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 determined to be 0.02%

[0057] Comparative Example 1

[0058] A cyclic chromium separation process, the other contents are the same as those of Embodiment 1 , except that the weak magnetic separation and strong magnetic separation in step SI are not included. And step S3 does not include the ball milling and the recycling of the obtained second-stage cyclone underflow and the second weak magnetically separated medium ore to the second-stage cyclone separation process.

[0059] The Cr2Os grade in the gravel-free ore is 3.21%, and the recovery rate is 59.73%; the Cr2Os grade in the chrome concentrate is 35.32%, and the recovery rate is 7.51%; the Cr2Os grade in the second chromite middling is 17.4%, and the recovery rate is 10.54%; the chromium content of the high-pressure leaching solution is 1.9%.

[0060] Comparative Example 2

[0061] A cyclic chromium separation process, the other contents are the same as those of Embodiment 1 , except that the weak magnetic separation and strong magnetic separation in step SI are not included.

[0062] The Cr2Os grade in the gravel-free ore is 3.21%, and the recovery rate is 59.73%; the Cr2Os grade in the chrome concentrate is 35.43%, and the recovery rate is 7.35%; the Cr2Os grade in the second chromite middlings is 17.1%, and the recovery rate is 10.33%; the chromium content of the high-pressure leaching solution is 0.7%.

[0063] Comparative Example 3

[0064] A cyclic chromium separation process, the other contents are the same as those of Embodiment 1 , except that the weak magnetic separation in step SI is not included.

[0065] The Cr2Os grade in the gravel-free ore was 3.21%, with a recovery rate of 59.73%; the Cr2Os grade in the chrome concentrate was 36.05%, with a recovery rate of 8.64%; the Cr2Os grade in the second chromite middlings was 19.4%, with a recovery rate of 12.54%; and the chromium content in the high-pressure leaching solution was 0.38%.

[0066] Comparative Example 4

[0067] A cyclic chromium separation process, the other contents are the same as those of Embodiment 1, except that the strong magnetic separation in step SI is not included.

[0068] The Cr2Os grade in the gravel-free ore is 3.21%, and the recovery rate is 59.73%; the Cr2Os grade of the first chromite middlings is 17.5%, and the recovery rate is 30.5%; the Cr2Os grade of the chrome concentrate is 36.44%, and the recovery rate is 8.09%; the Cr2Os grade of the second chromite middlings is 21.34%, and the recovery rate is 13.31%; the chromium content of the high-pressure leaching solution is 0.41%.

[0069] Comparative Example 5

[0070] A cyclic chromium separation process, the other contents are the same as those of Example 1, except that step S3 does not include the ball milling and the recycling of the obtained second-stage cyclone underflow and the second weak magnetically separated medium ore to the second-stage cyclone separation process.

[0071] The Cr2Os grade in the gravel-free ore is 3.21%, and the recovery rate is 59.73%; the Cr2Os grade of the first chromite middlings is 17.5%, and the recovery rate is 30.4%; the Cr2Os grade of the chrome concentrate is 38.22%, and the recovery rate is 19.14%; the Cr2Os grade of the second chromium middling is 26.8%, and the recovery rate is 7.9%; the chromium content of the high-pressure leaching solution is 1.4%.

[0072] The above embodiments and comparative examples illustrate that the present invention separates chromite from laterite nickel ore through a integrated method of multi-stage magnetic separation, spiral chute, multi-stage shaking table classification, and multi-stage cyclone separation, and the obtained chrome concentrate and chromium middlings have high recovery rates, the chrome concentrate recovery rate is 14-20%, and the chrome concentrate has a high grade (more than or equal to 36%) . This technical solution is beneficial to reducing the chromium removal pressure during the hydrometallurgical smelting of laterite nickel ore, and is beneficial to the comprehensive utilization of chromium elements.

[0073] The above are only preferred specific embodiments 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 by the present invention should be covered within the protection scope of the present invention.

Claims

What Is Claimed Is1 . A method for cyclic chromium processing, characteri zed in that it comprises :51 . The raw ore is sequentially subj ected to the ore washing process and the first-stage cyclone separation to obtain the first-stage cyclone overflow and the first-stage cyclone underflow, the first-stage cyclone underflow is subj ected to weak magnetic separation to obtain the first chrome middlings , and the first-stage cyclone underflow is sequential ly subj ected to weak magnetic separation and strong magnetic separation to obtain strong magnetically separated non-magnetic materials and strong magnetically separated separation magnetic materials ;52 . The strong magnetic separation magnetic material 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 chrome concentrate , second chrome middlings , second weak magnetic separation middlings and mixed light ore ;53 . After mixing the mixed light ore with the strong magnetically separated non-magnetic material , the mixture is ball-milled and stirred, and then second-stage cyclone separation is performed . The obtained second-stage cyclone overflow is mixed with the first-stage cyclone overflow and used to prepare high-pressure leaching stock solution . The obtained second-stage cyclone underflow and the second weak magnetically separated ore are mixed and ball-milled and then returned to the strong magnetic separation process in step S I .2 . The method for cyclic chromium processing according to claim 1 is characteri zed in that , in step S I , the magnetic field strength of the weak magnetic separation is 1000-2000 GS ; the magnetic field strength of the strong magnetic separation is 10000-20000 GS .3 . The method for cyclic chromium processing according to claim 1 is characteri zed in that , in step S I , the speci fic steps of thefirst-stage cyclone separation include : introducing the raw ore into the first-stage cyclone after the ore washing process to perform the first-stage cyclone separation, obtaining the first-stage cyclone overflow and the first-stage cyclone underflow, and the first-stage cyclone overflow is processed according to step S3 .4 . The method for cyclic chromium processing according to claim 3 is characteri zed in that , in step S I , the speci fic steps of weak magnetic separation are : the first-stage cyclone bottom flow is introduced into the first-stage weak magnetic separator for first-stage magnetic separation to obtain weak magnetically separated magnetic material and weak magnetically separated non-magnetic material , and the weak magnetically separated magnetic material is introduced into storage tank for weak magnetic machine and then classi fied by the spiral classi fier to obtain the first chrome middlings .5 . The method for cyclic chromium processing according to claim 4 is characteri zed in that , in step S I , the speci fic steps of strong magnetic separation are : the weak magnetically separated non-magnetic material is introduced into the strong magnetic separator for strong magnetic separation to obtain strong magnetically separated non-magnetic material and strong magnetically separated magnetic material , and the strong magnetical ly separated non-magnetic material is processed according to step S3 .6 . The method for cyclic chromium processing according to claim 1 is characteri zed in that , in step S2 , the speci fic steps of the spiral chute classi fication are : the strong magnetically separated magnetic material is introduced into the spiral chute to obtain the chute light ore and the chute heavy ore , and the chute light ore is used as a component of the mixed light ore in step S3 for post-processing .7 . The method for cyclic chromium processing according to claim 6 is characteri zed in that , in step S2 , the multi-stage shaking table classi fication includes a first-stage shaking table classi fication and a second-stage shaking table classi fication in sequence ;The first-stage shaking table classi fication step comprises : the chute heavy ore is introduced into the first-stage shaking table forfirst-stage shaking table classi fication to obtain the first-stage shaking table light ore and the first-stage shaking table heavy ore ; The second-stage shaking table classi fication step comprises : the first-stage shaking table heavy ore is introduced into the second-stage shaking table for second-stage shaking table classi fication to obtain the second-stage shaking table light ore , second-stage shaking table medium ore , and second-stage shaking table heavy ore ;The first-stage shaking table light ore and the second-stage shaking table light ore are both used as components of the mixed light ore material in step S3 for post-processing .8 . The method for cyclic chromium processing according to claim 7 is characteri zed in that , in step S2 , the steps of weak magnetic separation and spiral classi fication are : the second-stage shaking table heavy ore is fed into the second-stage weak magnetic separator for the second-stage weak magnetic separation to obtain the first weak magnetically separated concentrate and the first weak magnetically separated middlings , and the first weak magnetically separated concentrate is fed into the first-stage spiral classi fier for the first-stage spiral classi fication to obtain the chrome concentrate ; the second-stage shaking table medium ore is fed into the third-stage weak magnetic separator for the third-stage weak magnetic separation to obtain the second weak magnetically separated concentrate and the second weak magnetically separated middlings , and second weak magnetically separated middlings is processed according to step S3 ; the second weak magnetically separated concentrate and he first weak magnetically separated middlings are fed into the second-stage spiral classi fier together for the second-stage spiral classi fication to obtain the second chrome middlings .9 . The method for cyclic chromium processing according to claim 1 is characteri zed in that , step S3 speci fically comprises : mixing the mixed light ore with the strong magnetically separated non-magnetic material and then introducing it into a ball mill stirring tank for ball milling and stirring, and then introducing it into a second-stage cyclone separator for second-stage cyclone separation to obtain asecond-stage cyclone underflow and a second-stage cyclone overflow, and introducing the second-stage cyclone underflow and the second weak magnetically separated middlings into a ball mill for ball milling and then returned to strong magnetic separator to continue the strong magnetic separation process .10 . The method for cyclic chromium processing according to claim 9 is characteri zed in that , in step S3 , the speci fic steps of preparing the high-pressure leaching stock solution are : the first-stage cyclone overflow is transported to the finished product tank after passing through a first-stage impurity removal screen for first-stage impurity removal , and then transported to the raw ore slurry storage tank, the second-stage cyclone overflow is transported to the raw ore slurry storage tank after passing through a second-stage impurity removal screen for second-stage impurity removal , and the mixture in the raw ore slurry storage tank is introduced into a thickener containing a flocculant for solid-liquid separation, so as to obtain the high-pressure leaching stock solution .

Images