Process for rescreening titanium tailings

Abstract

The invention discloses a process for re-screening titanium tailings, which adopts a strong magnetic gravity separation closed-loop flow, is an effective supplement for limitation of a spiral chute gravity separation titanium separation process flow, solves the problems of high titanium separation tailings grade and ilmenite loss, and can ensure that the yield and the recovery rate reach higher indexes at the same time. Two spiral chutes with similar models are adopted in a titanium separation workshop to carry out a titanium tailing rescreening process, titanium middlings with the TiO2 grade being 38.5% are produced, the recovery rate of TiO2 is improved, coarse-particle gravel in tailings produced by a dressing plant is high-quality building aggregate, comprehensive utilization of gravel aggregate in the tailings is enhanced, waste is turned into wealth, and the production cost is reduced. Compared with the prior art, the method has the advantages that advantages can be created for tailing conveying and tailing pond capacity pressure reduction, economic benefits of companies can be improved, the content of recycled TiO2 after rescreening is 4.00% of the total content of tailings in a mine plant, and raw materials in underflow ore pulp of a thickener in a tailing workshop of a dressing plant are fully recycled and utilized.

Description

Technical Field

[0001] The invention belongs to the field of re-screening and re-recovery of titanium tailings, and relates to a process for re-screening of titanium tailings. Background Art

[0002] The global ilmenite reserves are about 740 million tons, mainly concentrated in Australia, China, India, South Africa and Kenya. China's ilmenite reserves account for 26.5% of the global reserves. In 2021, the output of titanium concentrate in Panzhihua City was 5.3 million tons, accounting for 78% of the total domestic output; my country imported 3.8 million tons of titanium concentrate and titanium ore throughout the year, an increase of 26.2% year-on-year. With the development of the national economy, the domestic demand for titanium concentrate has continued to grow. For many years, the domestic market gap for titanium concentrate has been large, and the product is in short supply.

[0003] With the continuous development, major infrastructure projects in Panzhihua and surrounding countries have been launched one after another, mainly including Lijiang-Panzhihua Railway, Panzhihua-Zhaotong Railway, Panzhihua-Dali Expressway, Yibin-Panzhihua Expressway (Yanjiang Expressway). According to statistics, the amount of sand and gravel aggregates used per kilometer of expressway is 54,000 to 60,000 tons, and the average amount of sand and gravel aggregates used per kilometer of high-speed railway is 70,000 tons; coupled with the continuous advancement of urbanization and industrialization in Panzhihua, the demand for sand and gravel aggregates in the surrounding construction and building materials markets is very huge.

[0004] Comprehensively utilize resources and "turn waste into treasure" to achieve efficient and cyclical utilization of resources, and transform resource advantages into economic advantages. The project complies with national industrial policies. Circular economy is an economic growth model that takes efficient and cyclical utilization of resources as the core, "reduction, reuse, and resource utilization" as the principle, and low consumption, low emissions, and high efficiency as the basic characteristics. It conforms to the concept of sustainable development and realizes the feedback cycle process of "resources-products-waste-renewable resources". Its essence is a sustainable ecological economy. The focus of developing a circular economy is to reduce resource consumption and improve resource utilization. The National Industrial Policy "Guidelines for Industrial Structure Adjustment (2019 Edition)" (revised in 2021) encourages Article 8, Item 11: Comprehensive utilization of advanced process technologies for metallurgical solid waste (including metallurgical mine waste rock, tailings, various types of dust, mud, slag, iron sheets, etc. generated by steel mills).

[0005] Efficient and scientific comprehensive recycling of our company's tailings, recovery of titanium resources and sand and gravel aggregate resources therein, not only turns waste into treasure, but also can bring good economic benefits, realize the virtuous cycle of resource economy and the coordinated and sustainable development of enterprises, society and environment. The raw materials screened and recycled are the tailings of our ore dressing plant. Although the tailings have been comprehensively recycled and utilized in the titanium dressing workshop, compared with the advanced enterprises in the Panzhihua area, its metal recovery rate is not high, and some ilmenite and sand and gravel aggregates are lost in the tailings. Therefore, in order to solve the above-mentioned technical problems, the technical solution of this application is set up. Summary of the invention

[0006] The purpose of the present invention is to provide a process for re-screening titanium tailings, thereby solving the above-mentioned technical problems.

[0007] The technical solution adopted by the present invention is as follows:

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

[0009] S1: Strong magnetic roughing

[0010] 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 to the slurry distributor installed in the strong magnetic roughing room located in the north of the thickener by the raw ore pump. The slurry flows by gravity into the linear vibrating screen through the distributor for slag screening. The screened products are stored and sold as sand and gravel aggregates. 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 pump pool of the tailings workshop of the ore dressing plant, and enter the existing conveying system of the tailings workshop as the final tailings. The selected concentrate flows by gravity into the strong magnetic rough concentrate pump pool and is pumped to the cyclone group located in the main plant for graded concentration operation.

[0011] S2: Grinding and separation

[0012] The cyclone group sedimentation flows by gravity into the ball mill for grinding operation, the cyclone group overflow merges with the ball mill discharge and flows by gravity into the magnetic separator for iron removal operation, the produced magnetic product flows by gravity into the secondary iron concentrate pump pool, and is pumped to the main plant of the grinding and selection workshop of the ore dressing plant by the secondary iron concentrate pump and returned to the existing iron selection system, the produced non-magnetic product flows by gravity into the gravity separation roughing feed pump pool and is pumped to the gravity separation room in the main plant by the roughing pump for gravity separation and titanium selection operation;

[0013] The titanium gravity separation process adopts one coarse four fine five-stage gravity separation, equipped with several spiral chutes of two types. The titanium middlings produced in the gravity separation room flow into the filter for dehydration treatment, and the filtrate returns to the gravity separation system and is transported as the final product to the titanium middling warehouse located in the northwest of the main plant by a belt conveyor for storage and sale;

[0014] The gravity separation tailings produced by the gravity separation titanium separation system flow by gravity into the pump pool and are lifted by the strong magnetic sweeping pump to the magnetic separator for the strong magnetic sweeping operation. The separation concentrate flows by gravity into the pump pool and is lifted by the sweeping concentrate pump to the cyclone group located in the main plant for graded concentration. The cyclone group sedimentation and the cyclone group sedimentation merge and flow by gravity into the wet overflow ball mill for grinding. The cyclone group overflow, 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 and the cyclone group product in step S1 share the grinding, separation and product conveying system.

[0015] S3: Tailings Thickening

[0016] The tailings separated by strong magnetic sweeping operation flow by gravity into the pump pool, and are pumped by sweeping tailings pumps into the cyclone group located in the environmental protection room in the east of the main plant for the first stage of tailings thickening operation. The overflow of the cyclone group flows by gravity into the inclined plate thickener for the second stage of tailings thickening operation. The overflow of the inclined plate thickener flows by gravity as circulating water into the tailings workshop of the ore dressing plant for recycling in the water return pump pool;

[0017] The tailings from the bottom flow of the inclined plate concentrator, the cyclone group sand settling and the strong magnetic roughing operation are combined as the final tailings. The final tailings concentration is 34%, and the average particle size of the tailings is 0.15mm. They flow by gravity into the diaphragm 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: 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%, a particle size of -200 mesh and a content of 40%.

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

[0020] Further: step S1 includes at least 3 linear vibrating screens of the ZKK3661-AT model, and at least 3 SLon3500 magnetic separators, the cyclones of which are of the FX350×8 model.

[0021] Furthermore, in step S2, the ball mill is a MQY3660 wet overflow type, the graded grinding product has a particle size of -200 mesh and a content of 50%, the magnetic separator includes at least two magnetic separators of model LCTC1200×4500, the iron ore concentrate pump is a 50ZJ-I-A50 slurry pump, and the roughing pump is a 300ZJ-I-A90 (85) slurry pump.

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

[0023] Furthermore: 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%.

[0024] Furthermore: in step S2, the model of the strong magnetic scavenging pump is a slurry pump of 300ZJ-I-A90 (85), the magnetic separator includes at least two magnetic separators of model SLon3500, the model of the scavenging concentrate pump is a slurry pump of 200ZJ-I-A70, and the cyclone group includes several cyclones of model FX350×8.

[0025] Furthermore, in step S3, the tailings scavenging pump is a slurry pump of model 300ZJ-I-A90, the cyclone model is FX250×24, and the inclined plate thickener model is NXB4000m2.

[0026] Furthermore: materials are transported between facilities by car, belt conveyor and pipeline, and there are roads connecting the workshops.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] 1. A process for re-screening titanium tailings. The titanium selection workshop uses two similar types of spiral chutes to re-screen titanium tailings, producing titanium middlings with a TiO2 grade of 38.5%, thereby improving the recovery rate of TiO2;

[0029] 2. In the present invention, the ore processing capacity of the ore dressing plant is 5 million tons / year, the total tailings volume is about 3.29 million tons / year, the tailings particle size is coarse (-12mm), and the coarse-grained sand and gravel in the tailings produced by the ore dressing plant are high-quality building aggregates. Strengthening the comprehensive utilization of sand and gravel aggregates in the tailings and turning waste into treasure can create favorable conditions for tailings transportation and reduce the storage capacity pressure of the tailings pond, and can also improve the company's economic benefits;

[0030] 3. In the present invention, the content of TiO2 recovered after re-screening by this application is 4.00% of the content in the total tailings of the mine, so that the raw materials in the underflow slurry from the thickener in the tailings workshop of the ore dressing plant can be fully recovered and utilized. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the specification can be arranged and designed in various different configurations.

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

[0033] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0034] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0035] Embodiment 1

[0036] The present invention discloses a process for rescreening titanium tailings. The specific implementation method of this embodiment is as follows: the raw materials come from the underflow of two NXZ-53m central transmission thickeners in the tailings workshop of the ore dressing plant. The underflow concentration is 40%, and the particle size -200 mesh content is 40%. The underflow slurry flows by gravity into the raw ore pump pool of this project, and is pumped to the slurry distributor arranged in the strong magnetic roughing room located in the north of the thickener through the raw ore pump (300ZJ-I-A90 (85) slurry pump).

[0037] The slurry flows by gravity through the distributor into three ZKK3661-AT linear vibrating screens for slag screening. The above-screen products are stored and sold as sand and gravel aggregates. The under-screen slurry flows by gravity into three SLon3500 magnetic separators for strong magnetic roughing operations. The selected tailings flow by gravity into the diaphragm pump feed pump pool of the tailings workshop of the concentrator and enter the existing conveying system of the tailings workshop as the final tailings. The selected concentrate flows by gravity into the strong magnetic rough concentrate pump pool and is pumped by the strong magnetic rough concentrate pump (200ZJ-I-A70(68) slurry pump) to the FX350×8 cyclone group located in the main plant of this project for graded concentration operations.

[0038] The sand settling of FX350×8 cyclone group flows by gravity into a MQY3660 wet overflow ball mill for grinding operation. The graded grinding product has a particle size of -200 mesh and a content of 50%. The overflow of the cyclone group merges with the discharge of the ball mill and flows by gravity into two LCTC1200×4500 magnetic separators for iron removal operation. The produced magnetic product flows by gravity into the secondary iron concentrate pump pool, and is pumped to the main plant building of the grinding and selection workshop of the ore dressing plant by the secondary iron concentrate pump 50ZJ-I-A50 slurry pump and returned to the existing iron selection system. The produced non-magnetic product flows by gravity into the gravity separation roughing feed pump pool and is pumped to the gravity separation room located in the main plant building of this project by the roughing pump (300ZJ-I-A90(85) slurry pump) for gravity separation and titanium selection operation.

[0039] The gravity separation titanium selection process adopts a one-roughing-four-fine-five-stage gravity separation process, equipped with 192 5LL-1200 (grooved) spiral chutes and 48 5LL-900 (grooved) spiral chutes.

[0040] The titanium middling produced in the gravity separation room flows by gravity into two GPT40 disc filters (one in use and one in reserve) for dehydration, and the filtrate returns to the gravity separation system. The moisture content of the dehydrated titanium middling is ≤12%, and the TiO2 content is ≥38%. It is transported to the titanium middling warehouse located in the northwest of the main plant of this project as the final product of this project via a B=650mm belt conveyor for storage and sale.

[0041] The gravity separation tailings produced by the gravity separation titanium system flow into the pump pool by gravity and are lifted by the strong magnetic scavenging pump (300ZJ-I-A90(85) slurry pump) to enter two SLon3500 magnetic separators for strong magnetic scavenging operation. The selected concentrate flows into the pump pool by gravity and is lifted by the scavenging concentrate pump (200ZJ-I-A70 slurry pump) to the FX350×8 cyclone group located in the main plant of this project for graded concentration operation. The cyclone group sedimentation and the FX350×8 cyclone group sedimentation are combined and flow into the MQY3660 wet overflow ball mill for grinding operation. The cyclone group overflow, FX350×8 cyclone group overflow and ball mill discharge are combined and flow into the iron removal operation. The cyclone group product shares the grinding, separation and product transportation system with the aforementioned FX350×8 cyclone group product.

[0042] The tailings separated by strong magnetic sweeping operation flow into the pump pool by gravity and are lifted by the sweeping tailings pump (300ZJ-I-A90 slurry pump) into the FX250×24 cyclone group located in the environmental protection room in the east of the main plant of this project for the first stage of tailings thickening operation. The overflow of the cyclone group flows by gravity into the NXB4000m2 inclined plate thickener for the second stage of tailings thickening operation. The overflow of the inclined plate thickener flows by gravity as circulating water into the tailings workshop of the ore dressing plant for recycling.

[0043] The tailings from the bottom flow of the inclined plate concentrator, the cyclone group sand settling and the strong magnetic roughing operation are combined as the final tailings. The final tailings concentration is 34%, and the average particle size of the tailings is 0.15mm. They flow by gravity into the diaphragm pump feed pump pool of the tailings workshop of the ore dressing plant and enter the existing conveying system of the tailings workshop.

[0044] This application adopts a strong magnetic gravity separation closed-circuit process, which is an effective supplement to the limitations of the spiral chute gravity separation titanium selection process. This process will solve the problems of high grade titanium tailings and ilmenite loss, while ensuring that higher indicators are achieved in both output and recovery rate.

[0045] Embodiment 2

[0046] The present invention discloses a process for re-screening titanium tailings. The specific implementation method of this embodiment is as follows: since the raw material contains cobalt elements and is mostly present in the form of sulfides, desulfurization flotation is used to enrich the cobalt elements during the titanium selection process, and experimental research is carried out on the cobalt elements to achieve further comprehensive recovery of resources, while also reducing the sulfur content in the titanium ore.

[0047] Compared with the flotation process, the metal recovery rate of fine-grained ilmenite in the gravity separation process is lower, and the lost fine-grained ilmenite will be concentrated in the bottom flow of the inclined plate concentrator. The present application achieves the purpose of recovering fine-grained ilmenite by recovering this part of ilmenite.

[0048] 270,000 t / a of secondary iron ore concentrate with a TFe grade of 20% is transported by a slurry pump back to the grinding and selection workshop of the ore dressing plant. Due to the large difference in ore selectivity, the metal recovery rate of the secondary iron ore concentrate in the existing production process of the grinding and selection workshop will be relatively low. This application separately treats the secondary iron ore concentrate to fully recover the secondary iron ore concentrate.

[0049] Embodiment 3

[0050] The present invention discloses a process for rescreening titanium tailings. The specific implementation method of this embodiment is as follows: the strong magnetic titanium separation equipment adopts the vertical ring pulsating magnetic separator produced by Ganzhou Jinhuan Company, which is convenient for ensuring the concentrate grade and metal recovery rate of the separation operation; the grading equipment adopts the Weihai Haiwang cyclone to control the grinding particle size, which is convenient for ensuring that the minerals entering the separation process are fully monomerized; the grinding equipment adopts the ball mill produced by Shenyang Northern Heavy Mining Machinery Manufacturing Co., Ltd.; the weak magnetic iron separation equipment adopts the wet countercurrent magnetic separator produced by Shenyang Longji Company, which is convenient for ensuring the concentrate grade and metal recovery rate of the separation operation.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

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 to the slurry distributor installed in the strong magnetic roughing room located in the north of the thickener by the raw ore pump. The slurry flows by gravity into the linear vibrating screen through the distributor for slag screening. The screened products are stored and sold as sand and gravel aggregates. 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 pump pool of the tailings workshop of the ore dressing plant, and enter the existing conveying system of the tailings workshop as the final tailings. The selected concentrate flows by gravity into the strong magnetic rough concentrate pump pool and is pumped to the cyclone group located in the main plant for graded concentration operation. S2: Grinding and separation The cyclone group sedimentation flows by gravity into the ball mill for grinding operation, the cyclone group overflow merges with the ball mill discharge and flows by gravity into the magnetic separator for iron removal operation, the produced magnetic product flows by gravity into the secondary iron concentrate pump pool, and is pumped to the main plant of the grinding and selection workshop of the ore dressing plant by the secondary iron concentrate pump and returned to the existing iron selection system, the produced non-magnetic product flows by gravity into the gravity separation roughing feed pump pool and is pumped to the gravity separation room in the main plant by the roughing pump for gravity separation and titanium selection operation; The titanium gravity separation process adopts one coarse four fine five-stage gravity separation, equipped with several spiral chutes of two types. The titanium middlings produced in the gravity separation room flow into the filter for dehydration treatment, and the filtrate returns to the gravity separation system and is transported as the final product to the titanium middling warehouse located in the northwest of the main plant by a belt conveyor for storage and sale; The gravity separation tailings produced by the gravity separation titanium separation system flow by gravity into the pump pool and are lifted by the strong magnetic sweeping pump to the magnetic separator for the strong magnetic sweeping operation. The separation concentrate flows by gravity into the pump pool and is lifted by the sweeping concentrate pump to the cyclone group located in the main plant for graded concentration. The cyclone group sedimentation and the cyclone group sedimentation merge and flow by gravity into the wet overflow ball mill for grinding. The cyclone group overflow, 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 and the cyclone group product in step S1 share the grinding, separation and product conveying system. S3: Tailings Thickening The tailings separated by strong magnetic sweeping operation flow by gravity into the pump pool, and are pumped by sweeping tailings pumps into the cyclone group located in the environmental protection room in the east of the main plant for the first stage of tailings thickening operation. The overflow of the cyclone group flows by gravity into the inclined plate thickener for the second stage of tailings thickening operation. The overflow of the inclined plate thickener flows by gravity as circulating water into the tailings workshop of the ore dressing plant for recycling in the water return pump pool; The tailings from the bottom flow of the inclined plate concentrator, the cyclone group sand settling and the strong magnetic roughing operation are combined as the final tailings. The final tailings concentration is 34%, and the average particle size of the tailings is 0.15mm. They flow by gravity into the diaphragm pump feed pump pool of the tailings workshop of the ore dressing plant and enter the existing conveying system of the tailings workshop.

2. A process for rescreening titanium tailings according to claim 1, characterized in that: 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%, a particle size of -200 mesh and a content of 40%.

3. A process for rescreening titanium tailings according to claim 1, characterized in that: In step S1, the model of the raw ore pump is 300ZJ-I-A90 (85) slurry pump, and the model of the strong magnetic rough concentrate pump is 200ZJ-I-A70 (68) slurry pump.

4. A process for rescreening titanium tailings according to claim 1, characterized in that: Step S1 includes at least 3 linear vibrating screens of the ZKK3661-AT model, and at least 3 SLon3500 magnetic separators, the cyclones of which are of the FX350×8 model.

5. A process for rescreening titanium tailings according to claim 1, characterized in that: In step S2, the ball mill is a 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 iron ore concentrate pump is model 50ZJ-I-A50 slurry pump, and the roughing pump is model 300ZJ-I-A90 (85) slurry pump.

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

7. A 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. A process for rescreening titanium tailings according to claim 1, characterized in that: In step S2, the model of the strong magnetic scavenging pump is a slurry pump of 300ZJ-I-A90 (85), the magnetic separator includes at least two magnetic separators of model SLon3500, the model of the scavenging concentrate pump is a slurry pump of 200ZJ-I-A70, and the cyclone group includes several cyclones of model FX350×8.

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