Process for resource utilization of flotation tailings

Abstract

The invention belongs to the field of flotation tailings, and relates to a flotation tailing resource utilization process which comprises the following steps: collecting tailings; part of tailings enter the hydrocyclone, the hydrocyclone is subjected to pre-classification, and the hydrocyclone outputs settled sand and overflow; the remaining tailings and settled sand output by the hydrocyclone enter a thickener together, and the output of the thickener is underflow and overflow clear water; wherein the overflow output by the hydrocyclone is subjected to concentration and filter pressing to prepare a building material; the underflow output by the thickener is mixed with the cementing material to form slurry with the concentration of 68%, and the slurry is conveyed to a goaf through a pump and a pipeline for filling. Tailing resources are fully utilized, and meanwhile the cementing cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of flotation tailings and relates to a process for the resource utilization of flotation tailings. Background Art

[0002] The treatment and utilization of tailings is a very important operation for mining enterprises. Traditional tailings treatment methods (open stacking or tailings pond storage) are prone to problems such as land occupation, soil and water pollution, and dust, threatening the surrounding ecological system and the health of residents. Based on the environmental protection concept of "green mine", making full use of tailings is an important way to achieve "waste-free mining".

[0003] The existing technology generally directly concentrates the tailings and then conducts cemented backfilling, or first conducts hydraulic classification on the tailings, and the overflow after classification is concentrated and then cemented and backfilled together with the classified sand sediment. The problems it has are:

[0004] The filling concentration is relatively low, and the amount of tailings consumed is small.

[0005] The situation of imbalance between mining and filling is serious. Because the amount of tailings consumed for filling is small and the goaf space is limited, the filling cannot consume all the tailings, and there will be some remaining tailings, resulting in an imbalance between mining and filling; that is, only part of the tailings can be treated, and there is still part of the tailings that are difficult to treat.

[0006] Due to the relatively low concentration and fine particle size of the underflow of the thickener, a large amount of cementitious material is required to reach the strength, resulting in a high ash-sand ratio and a high cost of the cementitious material. Summary of the Invention

[0007] The present application provides a process for the resource utilization of flotation tailings, which makes full use of tailings resources and at the same time reduces the cementing cost.

[0008] To achieve the above technical objectives, the technical solution adopted in the present application is a process for the resource utilization of flotation tailings, including the following steps:

[0009] Collect tailings;

[0010] Part of the tailings enters a hydrocyclone for pre-classification, and the hydrocyclone outputs sand sediment and overflow;

[0011] The remaining part of the tailings and the sand sediment output by the hydrocyclone jointly enter a thickener, and the output of the thickener is the underflow and clear water of the overflow;

[0012] Among them, the overflow output by the hydrocyclone is concentrated and pressure-filtered to make building materials; the underflow output by the thickener is mixed with a cementitious material to form a slurry with a concentration of 68%, and is transported to the goaf for filling through a pump and a pipeline.

[0013] As an improved technical solution of the present application, the pressure of the hydrocyclone is 0.1 MPa - 0.15 MPa.

[0014] As an improved technical solution of the present application, the diameter of the sand settling nozzle of the hydrocyclone is 40 mm.

[0015] As an improved technical solution of the present application, the content of -200 mesh in the feed of the thickener is 40% - 45%, and the content of -400 mesh is 30% - 35%.

[0016] As an improved technical solution of the present application, the underflow output from the thickener is mixed with the cementitious material to form a slurry with a concentration of 68%, and the ash - sand ratio of the cementitious material is 1:10.

[0017] Beneficial effects

[0018] The present invention improves the overall process flow and system equipment. By adjusting the filling pulp concentration, fineness, and the ratio of the cementitious material, it significantly improves the filling efficiency and economic benefits of the mine, and at the same time realizes the resource utilization of tailings. The specific technical effects are as follows:

[0019] I. Significantly improve the filling efficiency and relieve the problem of imbalance between mining and filling

[0020] On the premise of ensuring that the fluidity and strength of the filling pulp meet the technical requirements of mine filling, the present invention increases the filling pulp concentration from 62% to 68%. This optimization measure increases the tailings consumption per cubic meter of filling space from 0.92 tons to 1.10 tons, and the tailings consumption increases by about 19%. By increasing the utilization rate of tailings during filling, it effectively relieves the dilemma of imbalance between mining and filling during the mine - opening process, reduces the storage pressure of the tailings pond, extends the service life of the tailings pond, and at the same time provides a strong guarantee for the continuous and stable production of the mine.

[0021] II. Reduce the consumption of cementitious material and save production costs

[0022] The present invention optimizes and adjusts the ash - sand ratio of the filling cementitious material, reducing it from 1:8 to 1:10. Through experimental verification, this adjustment reduces the cementitious material consumption from 0.115 tons per cubic meter to 0.110 tons per cubic meter. Although the reduction in the amount of cementitious material used seems small, in large - scale mine filling operations, this optimization measure can significantly reduce the procurement cost of the cementitious material, bringing considerable economic benefits to the enterprise. At the same time, reducing the use of cementitious material also meets the requirements of green mine construction and reduces the potential impact on the environment.

[0023] III. Realize the resource utilization of tailings and improve environmental protection benefits

[0024] In traditional mine filling processes, due to limited filling space, some tailings are difficult to be effectively treated and are often piled up in tailing ponds, which not only occupy a large amount of land resources but also pose certain environmental risks. By optimizing the filling process, the present invention makes full use of tailings resources and converts the originally difficult-to-treat tailings into effective materials for mine filling. This resource utilization method not only solves the problem of tailings accumulation, reduces the potential harm of tailings to the environment, but also realizes the recycling of mine resources, improves the environmental protection benefits of mining enterprises, and promotes the sustainable development of the mining industry.

[0025] In summary, by optimizing the filling pulp concentration and binder ratio, the present invention realizes the efficient utilization of tailings, cost reduction, and resource recycling, bringing significant economic, technical, and environmental protection benefits to mining enterprises, and having broad application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The process flow diagram of the present application is shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] As Figure 1 shown, a process for the resource utilization of flotation tailings includes the following steps:

[0028] 1) Collect tailings; the amount of flotation tailings after the concentrator recovers copper and sulfur using the flotation process is 3500 - 4500 t / d. A branch is set in the flotation tailings tank to send part of the ore to the hydrocyclone for classification. The amount of tailings entering the hydrocyclone is adjusted by controlling the opening of the electric valve. 20% - 30% of the tailings first enter the buffer tank and are then pumped to the hydrocyclone for classification.

[0029] 2) 20%-30% of the tailings enter the hydrocyclone for pre-classification. The hydrocyclone outputs sand and overflow. Among them, the overflow output by the hydrocyclone is concentrated and filtered to make building materials. That is, the fine-grained tailings are not filled, but concentrated and filtered to make building materials, and they are made into building materials to achieve the complete utilization of tailings. The method of making building materials is as follows: The overflow of the hydrocyclone first enters the thickener for concentration, the underflow of the thickener enters the filter press for filtration, and the filtered product is dried, dispersed, mixed with additives, and ground fine to make building materials for external sale. Making building materials is to consume tailings. Making tailings into building materials for resource utilization plays the role of "turning waste into treasure". The originally difficult-to-treat tailings that have a bad impact on the environment have become resources useful to society, and there is no outstanding place in terms of performance compared with conventional materials. After classifying 20%-30% of the flotation tailings by the hydrocyclone, the overflow of the hydrocyclone, that is, the fine-grained fraction, goes to filtration, and the sand of the hydrocyclone, that is, the coarse-grained fraction, is mixed with the remaining part of the tailings. It is equivalent to taking away some fine particles in the flotation tailings. Therefore, the overall pulp going to filling becomes coarser. This article only targets the flotation tailings and related equipment of this mine. Appropriately coarser filling pulp can improve the pulp fluidity and filling strength, but it is not the coarser the better. If it is too coarse, the filling strength will decrease. The ratio of the hydrocyclone sand to the remaining part of the tailings is preferably 30-35%, which can not only improve the pulp fluidity but also improve the filling strength.

[0030] 3) The remaining part of the tailings and the sand output by the hydrocyclone enter the thickener together. The output of the thickener is underflow and overflow clear water; the hydrocyclone sand and the remaining 70%-80% of the tailings are pumped to the thickener for concentration together, making the overall particle size of the filling tailings appropriately coarser (the content of -200 mesh in the sand is 20%-30%, and the content of -200 mesh in the tailings is 70%-75%). The overflow of the hydrocyclone, that is, the fine-grained fraction, goes to filtration, and the sand of the hydrocyclone, that is, the coarse-grained fraction, is mixed with the remaining part of the tailings. It is equivalent to taking away some fine particles in the flotation tailings. Therefore, the overall pulp going to filling becomes coarser, that is, the content of -200 mesh in the feed of the filling thickener is 40%-45%. The yield of the hydrocyclone classification overflow is 20-25%, and the yield of the sand is 75-80%. The ratio of the hydrocyclone sand to the remaining part of the tailings is 30-35%. The advantage is that it makes the particle size of the filling tailings appropriately coarser, improving the pulp fluidity and filling strength. After the overall particle size of the filling tailings becomes appropriately coarser, there are the following advantages: 1. It is beneficial to improve the filling concentration and increase the consumption of tailings per cubic meter of space; 2. Reduce the ash-sand ratio and reduce the cost of the binder; 3. Improve the strength of the filling module and make it more solid.

[0031] The underflow output from the thickener is mixed with the cementitious material to form a slurry with a concentration of 68%. The parameter range of the underflow is that the underflow concentration range is 65.5% - 66.5%. The cementitious material consists of two materials, fine powder and additive, and the ratio of the two is fine powder:additive = 1:4. Tailings filling requires the mixing of cementitious material because it is necessary to solidify the pulp, enhance the strength of the filling body, and improve stability, and it is transported to the goaf for filling through pumps and pipelines.

[0032] As an improved technical solution of this application, the pressure of the hydrocyclone is 0.1 MPa - 0.15 MPa.

[0033] As an improved technical solution of this application, the diameter of the hydrocyclone sand settling nozzle is 40 mm.

[0034] As an improved technical solution of this application, the content of -200 mesh in the thickener feed is 40% - 45%, and the content of -400 mesh is 30% - 35%.

[0035] As an improved technical solution of this application, the underflow output from the thickener is mixed with the cementitious material to form a slurry with a concentration of 68%. The ash-sand ratio of the cementitious material is 1:10. After the cyclone sand settling is mixed with the remaining part of the tailings, the particle size of the thickener feed becomes slightly coarser than before. On the premise of ensuring that the fluidity and filling strength of the filling pulp meet the requirements, the thickener discharge concentration can be controlled at or increased to 68% at most.

[0036] Example 1

[0037] The flotation tailings volume of a certain mine in Anhui is 3500 - 4500 t / d, the concentration is 30%, and the content of -200 mesh is 70%.

[0038] First, 20% - 30% of the tailings are pre-classified using an FX250-PU*4 hydrocyclone. The pressure of the hydrocyclone is 0.1 MPa - 0.15 MPa, and the diameter of the sand settling nozzle is 40 mm. At this time, the content of -200 mesh in the classification overflow reaches 100%; the classification overflow of the hydrocyclone is concentrated by a thickener and then filtered under pressure. The pressure filtration product is dried, dispersed, mixed with additives, and ground fine to be made into building materials for external sale. It solves the problem that some tailings are difficult to handle due to insufficient filling space, that is, the tailings can be recycled using this process method.

[0039] The classified sand settling and the remaining 70% - 80% of the tailings are pumped to the thickener for concentration together. The content of -200 mesh in the thickener feed is 41.8%, and the content of -400 mesh is 30.9%. The thickener underflow is mixed with the cementitious material to form a slurry with a concentration of 68%, and it is transported to the goaf for filling through pumps and pipelines, where the ash-sand ratio of the cementitious material is 1:10. On the premise that the fluidity and filling strength of the filling pulp meet the requirements, the filling concentration is increased from 62% to 68%, and the tailings consumption per cubic meter of space is reduced from 0.92 t / m3 Increased to 1.10 t / m 3 (Calculated, at a filling concentration of 68% and a ash-sand ratio of 1:10, the tailings consumption per cubic meter of space is 1.10 t / m 3 , while at a filling concentration of 62% and a ash-sand ratio of 1:8, the tailings consumption per cubic meter of space is 0.92 t / m 3 ), the tailings consumption increased by approximately 19%, alleviating the dilemma of imbalance between mining and filling; the ash-sand ratio of the filling binder decreased from 1:8 to 1:10, and the binder consumption decreased from 0.115 t / m 3 to 0.110 t / m 3 , reducing the binder cost.

Claims

1. A process for the resource utilization of flotation tailings, characterized in that, It includes the following steps: Collect tailings; Part of the tailings enter a hydrocyclone, which performs preliminary classification. The hydrocyclone outputs sand and overflow; The remaining part of the tailings and the sand output from the hydrocyclone enter a thickener together. The output of the thickener is underflow and clear water of the overflow; Among them, the overflow output from the hydrocyclone is concentrated and filter-pressed to make building materials; the underflow output from the thickener is mixed with a binder to form a slurry with a concentration of 68%, and is transported to the goaf for filling through a pump and a pipeline.

2. The process for resource utilization of flotation tailings according to claim 1, characterized in that, The pressure of the hydrocyclone is 0.1 MPa - 0.15 MPa.

3. The process for resource utilization of flotation tailings according to claim 1, characterized in that, The diameter of the sand nozzle of the hydrocyclone is 40 mm.

4. The process for resource utilization of flotation tailings according to claim 1, characterized in that, The content of -200 mesh in the feed of the thickener is 40 - 45%, and the content of -400 mesh is 30 - 35%.

5. A process for the resource utilization of flotation tailings according to claim 1, characterized in that, The underflow output from the thickener is mixed with a binder to form a slurry with a concentration of 68%, and the ash-sand ratio of the binder is 1:

10.

6. The process for resource utilization of flotation tailings according to claim 1, characterized in that, The tailings entering the hydrocyclone account for 20% - 30% of the collected tailings.

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