A process for re-screening of titanium tailings

Abstract

The application discloses a process for re-screening titanium tailings, adopts a strong magnetic heavy separation closed circuit process, is an effective supplement for the limitation of a spiral chute heavy separation titanium separation process, solves the problems of high grade of titanium tailings and loss of ilmenite, and guarantees to reach higher indexes in terms of yield and recovery rate, two types of similar spiral chutes are used in a titanium separation workshop to carry out the titanium tailings re-screening process, TiO2 grade 38.5% of titanium middlings is produced, the TiO2 recovery rate is improved, coarse particle sand in tailings output by the dressing plant is high-quality building aggregate, the sand aggregate comprehensive utilization in tailings is strengthened, waste is turned into treasure, that is, favorable conditions can be created for tailings transportation and reduction of tailings reservoir capacity pressure, and the economic benefits of the company can be improved, the TiO2 content recovered after re-screening is 4.00% of the total tailings content in the dressing plant, so that the raw materials in the underflow slurry of the thickener in the tailings workshop of the dressing plant can be fully recovered and utilized.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of re-screening and re-recycling of titanium tailings, and relates to a process for re-screening titanium tailings. BACKGROUND

[0002] The global ilmenite reserves are about 740 million tons, mainly concentrated in Australia, China, India, South Africa and Kenya, among which the ilmenite reserves in China account for 26.5% of the global reserves. In 2021, the titanium concentrate output in Panzhihua City was 5.3 million tons, accounting for 78% of the total domestic output; China imported 3.8 million tons of titanium concentrate and titanium middlings in the whole year, increasing by 26.2% year-on-year. With the development of the national economy, the demand for domestic titanium concentrate is growing, and the gap in the domestic market for titanium concentrate has been large for many years, and the product is in short supply.

[0003] With the continuous development, major infrastructure projects in Panzhihua City and surrounding countries have been carried out, mainly including Lijiang-Panzhihua Railway in Dali, Panzhihua-Zhaotong Railway, Panzhihua-Dali Expressway, and Yibin-Panzhihua Expressway (along the Yangtze River). According to statistics, the sand and gravel consumption per kilometer of expressway is 54-60 thousand tons, and the average sand and gravel consumption per kilometer of high-speed rail is 70 thousand tons; in addition, with the continuous promotion of urbanization and industrialization construction in Panzhihua City, the demand for sand and gravel in the surrounding building and building material market is very large.

[0004] Comprehensive utilization of resources, "turning waste into treasure", realizing efficient utilization and recycling of resources, converting resource advantage into economic advantage, the project conforms to the national industrial policy, and circular economy is an economic growth mode with efficient utilization and recycling of resources as the core, "reduction, reuse and resource" as the principle, low consumption, low emission and high efficiency as the basic characteristics, in line with the concept of sustainable development, realizing the feedback type circular process of "resources-product-waste-regenerated resources", and its essence is a sustainable development ecological economy. The key to developing circular economy lies in reducing resource consumption and improving resource utilization. The national industrial policy "Guidance Catalogue for Industrial Structure Adjustment (2019 Edition)" (modified in 2021) encourages item 8, item 11: advanced comprehensive utilization technology of metallurgical solid waste (including metallurgical mine waste rock, tailings, various dust, mud, slag, iron skin and other generated by steel plants).

[0005] Efficient and scientific comprehensive recycling of tailings of the company, recycling of titanium resources and aggregate resources in the tailings, not only turns waste into treasure, but also brings good economic benefits, realizes the benign circulation of resource economy and the coordination and sustainable development of enterprise, society and environment, and the raw materials screened and recycled again are the tailings of the ore dressing plant, although the tailings have been comprehensively recycled in the titanium selection workshop, the metal recovery rate is not high compared with the advanced enterprises in Panxi area, and part of ilmenite and aggregate is lost in the tailings, therefore, in order to solve the above technical problems, the technical scheme of the application is arranged. SUMMARY

[0006] The purpose of the application is to provide a process for re-screening titanium tailings, which solves the above technical problems.

[0007] The technical scheme adopted by the application is as follows:

[0008] A process for re-screening titanium tailings, comprising strong magnetic roughing, grinding and separation, and tailings concentration, the specific operation steps are as follows:

[0009] S1: strong magnetic roughing

[0010] The raw material is the underflow slurry from the thickener in the tailings workshop of the ore dressing plant, the underflow slurry flows into the raw ore pump pool, is lifted by the raw ore pump to the slurry distributor arranged in the strong magnetic roughing room in the north of the thickener, the slurry flows into the linear vibrating screen through the distributor, and the screen is screened, the product on the screen is stacked and sold as aggregate, the slurry under the screen flows into the magnetic separator for strong magnetic roughing operation, the tailings are separated and flow into the membrane separation pump pool in the ore dressing plant tailings workshop, and are finally discharged into the existing conveying system in the tailings workshop, and the selected concentrate flows into the strong magnetic rough concentrate pump pool and is lifted by the strong magnetic rough concentrate pump to the cyclone group in the main plant building for classification and concentration operation;

[0011] S2: grinding and separation

[0012] The sand in the cyclone group flows into the ball mill for grinding operation, the overflow of the cyclone group and the ball mill discharge are combined and flow into the magnetic separator for iron removal operation, the magnetic product is output and flows into the secondary iron concentrate pump pool, is lifted by the secondary iron concentrate pump to the main plant building of the ore dressing plant grinding and separation workshop and returns to the existing iron selection system, and the non-magnetic product is output and flows into the gravity separation roughing feed pump pool, is lifted by the roughing pump to the gravity separation room in the main plant building for gravity separation and titanium selection operation;

[0013] The gravity separation and titanium selection process adopts one roughing and four cleaning five-stage gravity separation, several spiral sluices of two types are arranged, the titanium middlings produced in the gravity separation room flow into the filter for dewatering treatment, the filtrate returns to the gravity separation system, and is conveyed to the titanium middlings warehouse in the northwest of the main plant building by the belt conveyor as the final product and is stacked for sale;

[0014] The gravity separation tailings produced by the gravity separation and titanium selection system flow into the pump pool, are pumped into the magnetic separation machine by the strong magnetic sweeping selection pump, and enter the strong magnetic sweeping selection operation. The selected concentrate flows into the pump pool, is pumped to the cyclone group located in the main plant by the sweeping concentrate pump, and is subjected to classification and concentration operation. The cyclone group sand and the cyclone group sand are combined to flow into the wet overflow type ball mill for grinding operation. The cyclone group overflow, the cyclone group overflow and the ball mill discharge are combined to flow into the iron removal operation. The cyclone group product in step S2 is shared with the cyclone group product in step S1 for grinding and selection and product conveying system.

[0015] S3: Concentration of tailings

[0016] The tailings selected by the strong magnetic sweeping selection operation flow into the pump pool, are pumped into the cyclone group located in the east environmental protection room of the main plant by the sweeping tailings pump, and are subjected to tailings first-stage concentration operation. The cyclone group overflow flows into the inclined plate thickener for tailings second-stage concentration operation. The overflow of the inclined plate thickener is recycled as water into the water pump pool of the tailings workshop of the ore dressing plant.

[0017] The underflow of the inclined plate thickener, the cyclone group sand and the tailings of the strong magnetic roughing operation are combined as the final tailings. The final tailings have a concentration of 34% and an average particle size of 0.15 mm. The final tailings flow into the membrane pump feed pump pool of the tailings workshop of the ore dressing plant and enter the existing conveying system of the tailings workshop.

[0018] Further, the thickener in step S1 includes at least two NXZ-53m type thickeners, which are located at the center of the underflow slurry and are driven. The concentration of the underflow slurry is 40%, and the particle size is -200 mesh content of 40%.

[0019] Further, the raw ore pump in step S1 is a 300ZJ-I-A90(85) slurry pump, and the strong magnetic rough concentrate pump is a 200ZJ-I-A70(68) slurry pump.

[0020] Further, step S1 includes at least three ZKK3661-AT type linear vibrating screens and at least three SLon3500 type magnetic separators. The cyclone is FX350x8 type.

[0021] Further, the ball mill in step S2 is a MQY3660 wet overflow type, the classification grinding product has a particle size of -200 mesh content of 50%, the magnetic separator includes at least two LCTC1200x4500 type magnetic separators, the iron concentrate pump is a 50ZJ-I-A50 slurry pump, and the roughing pump is a 300ZJ-I-A90(85) slurry pump.

[0022] Further, the spiral chute in step S2 includes at least 192 spiral chutes of model 5LL-1200 (notched), and the other spiral chute includes at least 48 spiral chutes of model 5LL-900 (notched).

[0023] Further, the filter in step S2 includes at least 2 disc filters of model GPT40, one of which is in use and the other is standby, and the dewatered titanium middlings have water content of less than or equal to 12% and TiO2 content of greater than or equal to 38%.

[0024] Further, the strong magnetic scavenging pump in step S2 is a slurry pump of model 300ZJ-I-A90 (85), the magnetic separator includes at least 2 magnetic separators of model SLon3500, the scavenging concentrate pump is a slurry pump of model 200ZJ-I-A70, and the cyclone group includes a plurality of cyclones of model FX350x8.

[0025] Further, the scavenging tailings pump in step S3 is a slurry pump of model 300ZJ-I-A90, the cyclone is of model FX250x24, and the inclined plate thickener is of model NXB4000m2.

[0026] Further, the material transportation between facilities adopts the transportation modes of automobile, belt conveyor and pipeline, and there are roads connecting between workshops.

[0027] In summary, due to the adoption of the above technical scheme, the present application has the following beneficial effects:

[0028] 1. A process for re-screening titanium tailings, a titanium beneficiation plant adopting two spiral chutes of similar models for titanium tailings re-screening process, producing titanium middlings with TiO2 grade of 38.5%, and improving the recovery rate of TiO2.

[0029] 2. In the present application, the ore processing capacity of the beneficiation plant is 5 million tons / year, the total tailings amount is about 3.29 million tons / year, the tailings particle size is coarse (-12mm), and the coarse particles in the tailings produced by the beneficiation plant are high-quality building aggregates, which strengthens the comprehensive utilization of sand and aggregate in tailings, turns waste into treasure, creates favorable conditions for tailings transportation and reduces the pressure on tailings reservoir capacity, and improves the economic benefits of the company.

[0030] 3. In the present application, the content of TiO2 recovered after re-screening is 4.00% of the content in the total tailings of the beneficiation plant, so that the raw materials in the underflow slurry from the thickener in the tailings workshop are fully recovered and utilized. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application, i.e., the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the specification can be arranged and designed in various different configurations.

[0032] Therefore, the detailed description of the embodiments of the present application provided in the specification is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0033] It should be noted that the relational terms such as "first" and "second" and the like are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed or inherent to such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus including the element.

[0034] The features and performances of the present application will be further described in detail below with reference to the embodiments.

[0035] Embodiment one

[0036] The present application is a process for re-screening titanium tailings. The specific implementation of the present embodiment is as follows: the raw material comes from the underflow of two NXZ-53m center drive thickeners in the tailings workshop of the beneficiation plant, the underflow concentration is 40%, the particle size-200 mesh content is 40%, the underflow slurry flows into the raw ore pump pool of the project, and is sent to the slurry distributor arranged in the strong magnetic roughing room in the north of the thickener by the raw ore pump (300ZJ-I-A90(85) slurry pump).

[0037] The slurry is self-flowing into 3 ZKK3661-AT linear vibrating screens through a distributor for diaphragm screening, the screened product is stored and sold as sand and stone aggregate, the screened slurry is self-flowing into 3 SLon3500 magnetic separators for strong magnetic roughing, the tailings are self-flowing into a pump pool of a membrane pump in a tailings workshop of the concentrator, as the final tailings into the existing conveying system of the tailings workshop, the selected concentrate is self-flowing into a strong magnetic rough concentrate pump pool, and is lifted by a strong magnetic rough concentrate pump (200ZJ-I-A70(68) slurry pump) to FX350x8 cyclone group in the main plant of the project for grading and concentration.

[0038] The sand in the FX350x8 cyclone group is self-flowing into 1 MQY3660 wet overflow type ball mill for grinding, the product of the grading and grinding has a particle size of 200 mesh with a content of 50%, the overflow of the cyclone group and the discharge of the ball mill are self-flowing into 2 LCTC1200x4500 magnetic separators for iron removal, the magnetic product is self-flowing into a secondary iron concentrate pump pool, and is lifted by a secondary iron concentrate pump 50ZJ-I-A50 slurry pump to the main plant of the grinding workshop of the concentrator to return to the existing iron separation system, the non-magnetic product is self-flowing into a gravity separation roughing feed pump pool, and is lifted by a roughing pump (300ZJ-I-A90(85) slurry pump) to the gravity separation room in the main plant of the project for gravity separation and titanium extraction.

[0039] The gravity separation and titanium extraction process adopts a one-roughing-four-cleaning five-stage gravity separation process, and is equipped with 192 5LL-1200(notched) spiral sluices and 48 5LL-900(notched) spiral sluices.

[0040] The titanium middlings produced in the gravity separation room are self-flowing into 2 GPT40 disc filters (one in use and one in standby) for dewatering, the filtrate returns to the gravity separation system, the dewatered titanium middlings have a water content of ≤12% and a Ti02 content of ≥38%, and are conveyed by 1 B=650mm belt conveyor as the final product of the project to the titanium middlings warehouse in the northwest of the main plant of the project for storage and sale.

[0041] The gravity separation tailings produced by the gravity separation and titanium extraction system are self-flowing into a pump pool, and are lifted by a strong magnetic scavenging pump (300ZJ-I-A90(85) slurry pump) into 2 SLon3500 magnetic separators for strong magnetic scavenging, the selected concentrate is self-flowing into a pump pool, and is lifted by a scavenging concentrate pump (200ZJ-I-A70 slurry pump) to the FX350x8 cyclone group in the main plant of the project for grading and concentration, the sand in the cyclone group is self-flowing into the MQY3660 wet overflow type ball mill together with the sand in the FX350x8 cyclone group for grinding, the overflow of the cyclone group, the overflow of the FX350x8 cyclone group and the discharge of the ball mill are self-flowing into the iron removal system, and the product of the cyclone group and the product of the FX350x8 cyclone group share the grinding and separation system and the product conveying system.

[0042] The tailings of the strong magnetic separation operation are self-flowed into a pump pool, are lifted by a tailings pump (300ZJ-I-A90 slurry pump) into a FX250x24 cyclone group located in the environmental protection room in the east of the main plant of the project for a first-stage concentration operation of tailings, the overflow of the cyclone group is self-flowed into a NXB4000m2 inclined plate thickener for a second-stage concentration operation of tailings, and the overflow of the inclined plate thickener is self-flowed into a tailings workshop of the concentrator as circulating water.

[0043] The underflow of the inclined plate thickener, the sand of the cyclone group and the tailings of the rough magnetic separation operation are combined as final tailings, the concentration of the final tailings is 34%, the average particle size of the tailings is 0.15mm, and the final tailings are self-flowed into a membrane pump feeding pump pool of a tailings workshop of the concentrator, and are fed into an existing conveying system of the tailings workshop.

[0044] The application adopts a strong magnetic gravity separation closed circuit process, is an effective supplement to the limitation of the spiral chute gravity separation titanium selection process, solves the problems of high grade of tailings of titanium selection and loss of ilmenite, and can guarantee to reach higher indexes in terms of yield and recovery rate.

[0045] Embodiment two

[0046] The embodiment of the process for reselecting titanium tailings is as follows: the raw material contains cobalt elements and is mainly in the form of sulfide, the cobalt elements are enriched by desulfurization flotation in the titanium selection process, and experimental research work is conducted on the cobalt elements, so that resources are further comprehensively recovered, and the content of sulfur in the titanium middlings is reduced.

[0047] Compared with the flotation process, the metal recovery rate of fine particle ilmenite is low in the gravity separation process, and the fine particle ilmenite is concentrated in the underflow of the inclined plate thickener, and the application recovers the fine particle ilmenite to achieve the purpose of fine particle ilmenite recovery.

[0048] 27.00 million tons of TFe grade 20% of secondary iron concentrate per year is output by the slurry pump and is returned to the grinding and separation workshop of the concentrator, due to large differences in ore selectivity, the metal recovery rate of the secondary iron concentrate in the existing production process of the grinding and separation workshop is relatively low, and the application separately processes the secondary iron concentrate to fully recover the secondary iron concentrate.

[0049] Embodiment three

[0050] The embodiment of the application is a process for re-screening titanium tailings, and the specific implementation mode is as follows: the strong magnetic separation titanium equipment adopts the vertical ring pulsating magnetic separator produced by Ganzhou Jinhuang Company, so as to facilitate guarantee of the concentrate grade and metal recovery rate of the separation operation; the grading equipment adopts the Weihaishan cyclone to control the grinding granularity, so as to facilitate guarantee of full single liberation of the minerals entering the separation process; the grinding equipment adopts the ball mill produced by Shenyang Beifang Heavy Mineral Machine Co., Ltd.; and the weak magnetic separation iron equipment adopts the wet countercurrent type magnetic separator produced by Shenyang Longji Company, so as to facilitate guarantee of the concentrate grade and metal recovery rate of the separation operation.

[0051] The above merely describes the preferred embodiments of the application, but should not be used to limit the protection scope of the application, and any modification, equivalent replacement and improvement made by any person skilled in the art within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A process for rescreening titanium tailings, characterized in that: Including strong magnetic roughing, grinding separation and tailings concentration, the specific operation steps are as follows: S1: Strong magnetic roughing The raw materials come from the underflow slurry of the thickener in the tailings workshop of the ore dressing plant. The underflow slurry flows by gravity into the raw ore pump pool, and is pumped by the raw ore pump to the slurry distributor installed in the strong magnetic roughing room located north of the thickener. The slurry flows by gravity through the distributor into the linear vibrating screen for slag screening. The overscreen product is stored and sold as sand and gravel aggregate. The underscreen slurry flows by gravity into the magnetic separator for strong magnetic roughing operation. The selected tailings flow by gravity into the diaphragm pump feed sump of the tailings workshop of the ore dressing plant, and as the final tailings, enter the existing conveying system of the tailings workshop. The selected concentrate flows by gravity into the strong magnetic roughing concentrate pump pool, and is pumped by the strong magnetic roughing concentrate pump to the cyclone group located in the main powerhouse for graded concentration operation. S2: Grinding and separation The sand settling in the cyclone group flows by gravity into the ball mill for grinding. The overflow of the cyclone group merges with the discharge of the ball mill and flows by gravity into the magnetic separator for iron removal. The produced magnetic product flows by gravity into the secondary iron concentrate pump pool, and is pumped by the secondary iron concentrate pump to the main plant building of the ore dressing plant and returned to the existing iron separation system. The produced non-magnetic product flows by gravity into the gravity separation roughing feed pump pool and is pumped by the roughing pump to the gravity separation room in the main plant building for gravity separation and titanium separation. The titanium gravity separation process adopts a five-stage gravity separation process with one coarse and four fine stages. It is equipped with several spiral chutes of two types. The titanium middlings produced in the gravity separation room flow into the filter for dehydration. The filtrate returns to the gravity separation system and is transported as the final product by belt conveyor to the titanium middling warehouse located in the northwest of the main plant for storage and sale. The gravity separation tailings produced by the gravity separation titanium system flow by gravity into the pump pool and are lifted by the strong magnetic scavenging pump to the magnetic separator for strong magnetic scavenging operation. The separated concentrate flows by gravity into the pump pool and is lifted by the scavenging concentrate pump to the cyclone group located in the main powerhouse for classification and concentration. The cyclone group sediments and enters the wet overflow ball mill for grinding. The cyclone group overflow and the ball mill discharge merge and flow by gravity into the iron removal operation. The cyclone group product in step S2 shares the same grinding and product conveying system with the cyclone group product in step S1. Iron removal is to facilitate subsequent gravity separation. The purpose of gravity separation is to select the final product "titanium middlings". S3: Tailings Thickening The tailings separated by strong magnetic scavenging operation flow by gravity into the pump pool, and are pumped by the scavenging tailings pump into the cyclone group located in the environmental protection room in the east of the main powerhouse for the first stage of tailings thickening. The overflow of the cyclone group flows by gravity into the inclined plate thickener for the second stage of tailings thickening. The overflow of the inclined plate thickener flows by gravity as circulating water into the return water pump pool of the tailings workshop of the mineral processing plant for recycling. The tailings from the inclined plate concentrator bottom flow, cyclone group sand settling and strong magnetic roughing operation are combined as the final tailings. The final tailings concentration is 34%, the average tailings particle size is 0.15mm, and they flow by gravity into the diaphragm pump feed pump pool of the tailings workshop of the mineral processing plant and enter the existing conveying system of the tailings workshop.

2. The process for rescreening titanium tailings according to claim 1, wherein: In step S1, the thickener includes at least two NXZ-53m thickeners, which are located at the center of the underflow slurry for transmission. The underflow slurry has a concentration of 40% and a particle size of -200 mesh with a content of 40%.

3. The process for rescreening titanium tailings according to claim 1, wherein: In step S1, the model of the raw ore pump is 300ZJ-I-A90 slurry pump, and the model of the strong magnetic coarse concentrate pump is 200ZJ-I-A70 slurry pump.

4. The process for rescreening titanium tailings according to claim 1, wherein: Step S1 includes at least three ZKK3661-AT linear vibrating screens, at least three SLon3500 magnetic separators, and a cyclone of FX350×8.

5. The process for rescreening titanium tailings according to claim 1, characterized in that: In step S2, the ball mill is an MQY3660 wet overflow type, the graded grinding product particle size is -200 mesh and the content is 50%, the magnetic separator includes at least two magnetic separators of model LCTC1200×4500, the model of the secondary iron ore concentrate pump is 50ZJ-I-A50 slurry pump, and the model of the roughing pump is 300ZJ-I-A90 slurry pump.

6. The process for rescreening titanium tailings according to claim 1, characterized in that: In step S2, one type of spiral chute includes at least 192 grooved spiral chutes of model 5LL-1200, and the other type of spiral chute includes at least 48 grooved spiral chutes of model 5LL-900.

7. The process for rescreening titanium tailings according to claim 1, characterized in that: In step S2, the filter includes at least two disc filters of model GPT40, one of which is used and the other is used as a backup. The water content of the titanium ore after dehydration is ≤12% and the TiO2 content is ≥38%.

8. The process for rescreening titanium tailings according to claim 1, characterized in that: In step S2, the strong magnetic scavenging pump is a slurry pump of model 300ZJ-I-A90, the magnetic separator includes at least two magnetic separators of model SLon3500, the scavenging concentrate pump is a slurry pump of model 200ZJ-I-A70, and the cyclone group includes several cyclones of model FX350×8.

9. The process for rescreening titanium tailings according to claim 1, characterized in that: In step S3, the tailings scavenging pump is a 300ZJ-I-A90 slurry pump, the cyclone is FX250×24, and the inclined plate thickener is NXB4000m2.

10. The process for rescreening titanium tailings according to claim 1, characterized in that: Materials are transported between facilities by car, belt conveyor and pipeline, and there are roads connecting the workshops.