Flocculant type selection method for reducing graded fine tailing filling mining cost

Abstract

The invention discloses a flocculating agent type selection method for reducing graded fine tailing filling mining cost, and belongs to the technical field of tailing filling mining. The method comprises the following implementation steps: carrying out grain size grading and mineral composition analysis on the cyclone classification fine tailings, and carrying out a tailings flocculation sedimentation test on each flocculant to obtain sedimentation time and sedimentation height data; performing regression analysis to obtain a flocculating settling function, performing derivation on the flocculating settling function, and obtaining a flocculating settling rate at an initial moment; calculating a flocculation effect index according to the ratio of the flocculation sedimentation underflow concentration to the supernatant turbidity; respectively calculating the cost performance of the flocculating settling rate and the cost performance of the flocculating effect on the basis of the cost of the flocculating agent; and according to the flocculation efficiency and the flocculation quality requirement, determining a corresponding weight to calculate the flocculation index cost performance, thereby carrying out a flocculant type selection decision. The method can meet the requirements of tailing filling mining on productivity, slurry preparation and backwater utilization rate, and can also reduce the filling mining cost, thereby promoting the application of the graded fine tailings in filling mining.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive utilization of bulk solid waste and green filling mining with energy conservation and emission reduction, and in particular to a flocculant selection method for reducing the cost of graded fine tailings filling mining. Background Art

[0002] my country's iron ore grade is low, and the tailings discharge is large, accounting for about 40% of the total tailings discharge. Usually, tailings are discharged into tailings ponds, which not only occupies a large amount of land, but also poses a major safety risk. As the storage capacity of existing tailings ponds decreases year by year and gradually tends to be full, the site selection and investment of new tailings ponds are facing difficulties. Therefore, tailings filling is a way to solve the tailings discharge, and it is also the best choice for the comprehensive utilization of bulk solid waste and the creation of green mines. Filling mining is to densely slurry tailings and transport them to underground goafs through pipelines to avoid stacking on the surface to pollute the environment. At the same time, the tailings filling body can also control the ground pressure of the mining area, improve the stability of the filling mining area, and achieve the purpose of preventing and controlling induced geological disasters. At present, tailings filling mining is widely used in non-ferrous gold and other precious metal mines, and iron ore filling mining has also developed rapidly in the past 10 years.

[0003] Iron ore has low metal value, high filling mining cost and poor economic benefits. Therefore, the research and development and application of low-cost green filling cementitious materials can significantly reduce the cost of iron ore tailings filling mining. However, with the development of ore dressing and grinding equipment and the advancement of ore dressing technology, the particle size of tailings is getting smaller and smaller. At the same time, in order to comprehensively utilize tailings resources, cyclones are used to classify the whole tailings, and the coarse tailings are used for construction fine sand, while the fine tailings are used for filling mining. Therefore, the flocculation, concentration and dehydration of the classified fine tailings are the key links in filling mining.

[0004] The graded fine tailings have high mud content, long natural sedimentation and concentration time, and low efficiency. Flocculation sedimentation is a necessary choice for the thickening of graded fine tailings. Due to the great differences in different types of flocculants, product prices and tailings flocculation effects. Therefore, flocculant selection is the most important link in the graded fine tailings thickening filling mining technology, which has an important impact on the preparation of tailings slurry, slurry pipeline transportation, filling body strength, mining cost and the utilization of concentrator return water. Due to the huge water consumption of the concentrator, it is also of great significance to improve the utilization rate of concentrator return water, reduce wastewater discharge, and protect mine water resources.

[0005] According to the different tailings mineral components and physical and chemical characteristics, tailings flocculant selection tests have been carried out. Chen Qiaoying et al. (2004) carried out flocculant selection tests for red mud sedimentation and separation. # 、British Alclar-600 #The red mud sedimentation test was carried out using three flocculants produced by the company. The flocculant was selected by comparing the sedimentation rates and supernatant turbidity of the three flocculants. For the neutralization of slurry sedimentation and dehydration, Shen Qingfeng et al. (2019) used polyphenylamide series flocculants (PAM-1, PAM-2, PAM-3) to carry out experimental research on flocculant type, flocculant dosage and slurry concentration. Flocculants were selected according to the sedimentation rate and supernatant turbidity. Zheng Yinzhu (2023) conducted an optimization selection test on flocculants for flocculation and sedimentation of Tonglushan Mine tailings. The flocculant was selected by comparing the flocculation and sedimentation rates of five flocculants and qualitatively considering the flocculant test effect and production cost. Dang Jiandong et al. (2021) conducted a test on the sedimentation performance and flocculant selection of the whole tailings of Shaxi Copper Mine. Three flocculants, Tianrun P-1, Tianrun P-2 and Nol N-1, were selected to carry out the whole tailings flocculation and sedimentation test. By comparing the sedimentation rate, solid flux, underflow concentration and flocculant price of the three flocculants, the flocculant selection decision was made. The problems of low concentration efficiency of fine tailings, difficult unloading during dehydration, and low filter press efficiency were solved; Yue Shouyan et al. (2024) used Aisen-65M series flocculants, BK816 series flocculants of Mining and Metallurgical Technology Group, and several flocculants from a factory in Jiangsu to carry out the optimization of flocculants for a copper tailings slurry in Ecuador. Flocculants were selected based on the tailings sedimentation rate and the reduction of turbidity. Xu Xingwei et al. (2024) conducted a study on the selection of flocculants for manganese iron ore mud and water separation. Drawing on the previous experimental data and experience, the comparative analysis method was used to select different flocculants and preparation concentrations for tailings flocculation and sedimentation tests. The flocculant is selected according to the tailings sedimentation rate, supernatant turbidity and sedimentation ratio. CN116559034A discloses a method for selecting a polyacrylamide flocculant for tailings concentration. The polyacrylamide flocculant with the fastest sedimentation rate and the lowest solid particle content in the low turbidity water layer is selected to obtain a polyacrylamide flocculant suitable for the tailings slurry.

[0006] In summary, the existing research on tailings flocculant selection has problems in the following two aspects:

[0007] (1) Select flocculants based on the tailings flocculation and sedimentation rate. The tailings sedimentation rate is related to the tailings production capacity. The faster the sedimentation rate, the higher the tailings flocculation production capacity. Currently, most studies on flocculant selection select flocculants based on the maximum tailings flocculation and sedimentation rate. It is true that the better the performance of the flocculant product, the faster the sedimentation rate, and of course the higher the product price. However, increasing the amount of low-cost flocculants may achieve a faster sedimentation rate than high-cost flocculants, and the cost of low-cost flocculants is lower than that of high-cost flocculants. Therefore, using the flocculation sedimentation rate cost-effectiveness (sedimentation rate / flocculant cost) is more economical and reasonable than using sedimentation rate to select flocculants.

[0008] (2) The effect of tailings flocculation effect on flocculant selection is not considered. The tailings flocculation effect refers to two indicators: the bottom flow limit concentration of tailings flocculation and the turbidity of the supernatant overflow water. The higher the bottom flow limit concentration of tailings flocculation and the lower the supernatant turbidity, the better the tailings flocculation effect. Different tailings have different mineral compositions and particle size distributions, as well as different tailings flocculation effects. Obviously, different flocculant types will also affect the tailings flocculation effect. Therefore, it is very necessary to consider the tailings flocculation effect on flocculant selection. However, most current flocculant selection methods do not consider the effect of flocculation effect on flocculant selection. A small number of flocculant selection methods only observe and qualitatively compare the flocculation effects of different flocculants, which is one of the main problems in all current flocculant selection processes. Summary of the invention

[0009] In view of the problems existing in the current flocculant selection method for tailings flocculation and density, the present invention discloses a flocculant selection method for tailings flocculation, which comprehensively considers flocculant cost, sedimentation rate, underflow limit concentration and supernatant turbidity, and discloses a flocculant selection method. The selection method selects the weight of the sedimentation rate cost performance and the weight of the flocculation effect cost performance, calculates the tailings flocculation index cost performance for flocculant selection, and can meet the requirements of filling mining for tailings production capacity and flocculation effect (underflow concentration and supernatant turbidity).

[0010] The present invention discloses a method for selecting a flocculant for reducing the cost of graded fine tailings filling mining, and the specific steps are as follows:

[0011] 1). Determine the concentration of graded tailings; sample the graded fine tailings for mineral composition and particle size analysis; select N types of flocculants suitable for the tailings, and prepare flocculant solutions with a mass concentration of 0.1% respectively;

[0012] 2). Carry out tailings flocculation and sedimentation tests for each flocculant and graded fine tailings concentration, and obtain tailings flocculation and sedimentation time and sedimentation height data for each flocculant;

[0013] 3). Using the polynomial regression analysis method, polynomial regression analysis is performed on the tailings flocculation sedimentation time and sedimentation height data to obtain the tailings flocculation sedimentation function;

[0014] 4). Take the derivative of the tailings flocculation and sedimentation function, evaluate its derivative function at the initial time, and obtain the graded fine tailings flocculation and sedimentation rate V i , where i = 1 to N;

[0015] 5). According to the cost of flocculant C Ti , i = 1 ~ N, calculate the cost performance of tailings flocculation and sedimentation rate of each flocculant: V Xi =V i / C Ti , i = 1 to N;

[0016] 6). According to step 2), calculate the bottom flow limit concentration C of tailings flocculation and sedimentation of each flocculant Li and supernatant turbidity C Ui , calculate the tailings flocculation effect of each flocculant: W i =C Li / C Ui ;

[0017] 7). Based on the cost of each flocculant C Ti , calculate the cost performance of tailings flocculation effect: X ci =W i / C Ti , i = 1 to N;

[0018] 8). According to the demand for tailings volume in the mine filling mining scale, the requirements for underflow concentration in the preparation of high-concentration slurry and the requirements for the utilization rate of the concentrator return water, determine the cost-effectiveness weight α of the tailings flocculation sedimentation rate and the cost-effectiveness weight β of the flocculation effect;

[0019] 9). According to steps 5), 7), and 8), calculate the cost performance of tailings flocculation index: Z ci =αC Xi +βX ci Among them, C Xi Represents the cost performance of sedimentation rate, X ci Represents the cost performance of flocculation effect, Z ci Represents the cost-effectiveness of fine tailings flocculation indicators.

[0020] 10). Cost performance of fine tailings flocculation index Z ci The flocculant corresponding to the maximum value is selected as the flocculant for flocculation and sedimentation of graded fine tailings.

[0021] Preferably, in step 3), a flocculation and sedimentation test is performed on each type of graded fine tailings to obtain the test data {(t1, h1), (t2, h2), ..., (t m ,h m )} i , i=1~N.

[0022] Preferably, in step 3), the mortar underflow limit concentration is calculated according to the final settling time of the tailings flocculation settling test; the underflow limit concentration calculation formula is as follows:

[0023]

[0024] Where: C 底流 ——underflow limit concentration, %; W 砂 ——The mass of tailings in tailings slurry, g;

[0025] W水 ——The mass of water in the mortar, g; ω 水 ——Mass of upper clarified water d, g.

[0026] Preferably, in step 4), the tailings flocculation sedimentation function is derived, d[f i {(t1,h1),(t2,h2),…(t m ,h m )}]dt, i = 1 ~ N, and evaluate its derivative at the initial time (t = 0), thus obtaining the tailings flocculation settling rate V ni , i=1~N.

[0027] Preferably, in step 8), α=0.7, β=0.3. Calculation of tailings flocculation index cost performance: Z ci =αC Xi +βX ci Among them, C Xi Represents the cost-effectiveness of flocculation sedimentation rate, X ci Represents the cost-effectiveness of flocculation effect.

[0028] The flocculant selection method for reducing the cost of graded fine tailings filling mining disclosed in the present invention has the following main features: comprehensively considering factors such as flocculant cost, sedimentation rate, underflow concentration and supernatant turbidity, firstly calculating the sedimentation rate cost performance and flocculation effect cost performance respectively according to the flocculant cost and flocculation sedimentation test results; then determining the weight of the sedimentation rate cost performance and the weight of the flocculation effect cost performance respectively according to the demand for tailings production capacity of mine filling mining, the requirement for underflow concentration of high-concentration filling slurry preparation and the requirement for supernatant turbidity of return water utilization of the concentrator, and calculating the cost performance of tailings flocculation index; finally, making a flocculant selection decision for graded fine tailings according to the cost performance of tailings flocculation index. The selection method can adapt to the demand for tailings production capacity of filling mining and realize the requirements of high-concentration filling technology and return water utilization, and can also reduce the promotion and application of graded fine tailings in filling mining, which is of great significance for improving the economic benefits of graded fine tailings filling mining and promoting environmental protection in filling mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a particle size distribution curve of the classified fine tailings in the implementation case of the present invention;

[0030] Figure 2 It is the regression curve and regression function of the flocculation and sedimentation of graded fine tailings in the implementation case of the present invention. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the flocculant selection method for efficient and low-cost flocculation and concentration of graded fine tailings disclosed in the present invention and the key technologies and implementation steps involved, the following will be described in detail with reference to the accompanying drawings and specific implementation cases. The implementation plan specifically includes the following 6 steps:

[0032] Step 1: Analysis of physical and chemical characteristics of graded fine tailings

[0033] (1) A large iron ore mine was mined by cyclone-classified fine tailings filling method. The graded fine tailings were -150 mesh. The particle size range was 0.28 to 181.6 μm. The content of -75 μm (-200 mesh) fine sand in the tailings was 88.1%. The content of -38 μm (-400 mesh) ultrafine sand was 53.15%. The tailings particle size distribution curve is shown in Figure 1 , the particle size distribution characteristic values ​​are shown in Table 1.

[0034] Table 1 Characteristic values ​​of particle size distribution of 150 mesh tailings from a large iron mine

[0035]

[0036] (2) According to the cyclone model and mortar inlet pressure of the concentrator, the concentration of cyclone-classified fine tailings is 15%. For the tailings slurry of tailings flocculation and sedimentation test, the cyclone-classified fine tailings are first sampled and concentrated into dry sand, and then the dry tailings are diluted with mine water to a tailings slurry concentration of 15%, which is used as the tailings slurry for the flocculant selection test.

[0037] Step 2: Select flocculant to prepare flocculant solution

[0038] (1) Six types of flocculants were selected based on experimental experience. See Table 2 for flocculant types, prices and numbers.

[0039] Table 2 Types and prices of polyacrylamide flocculants

[0040]

[0041] (2) For each flocculant in Table 2, a flocculant solution with a flocculant mass concentration of 0.1% was prepared using tap water and used for the fine tailings flocculation and sedimentation test.

[0042] Step 3: Classified fine tailings flocculation and sedimentation test

[0043] (1) According to the graded fine tailings concentration and flocculant solution, tailings flocculation and sedimentation tests were carried out for each flocculant. The tailings sedimentation time and sedimentation height and supernatant turbidity test data were obtained and are shown in Table 3.

[0044] Table 3 Results of the flocculation and sedimentation test of graded fine tailings

[0045]

[0046]

[0047] (2) According to the final settling time of the tailings flocculation settling test, the bottom flow limit concentration of the tailings slurry is calculated; the bottom flow limit concentration calculation formula is as follows:

[0048]

[0049] Where: C 底流 ——underflow limit concentration, %; W 砂 ——The mass of tailings in tailings slurry, g;

[0050] W 水 ——The mass of water in the mortar, g; ω 水 ——The mass of upper clarified water, g.

[0051] Step 4: Calculation of flocculation and settling rate of graded fine tailings

[0052] According to the experimental data of flocculation settling time and settling height of graded fine tailings in Table 3, polynomial regression analysis was first used to obtain the regression curve of flocculation settling of graded fine tailings (see Figure 2 ) and flocculation sedimentation function (see Table 4); then, the tailings flocculation sedimentation function is differentiated, and the derivative function is derived at the initial test time (t=0), and the tailings sedimentation derivative function value is calculated, thereby obtaining the tailings flocculation sedimentation rate (see Table 4).

[0053] Table 4 Calculation results of flocculation and sedimentation rate of graded fine tailings

[0054]

[0055] Step 5: Calculation of cost performance of flocculation effect of graded fine tailings

[0056] (1) According to the tailings flocculation sedimentation rate and flocculant cost, calculate the cost performance ratio V of each flocculant for tailings flocculation sedimentation rate Xi =V i / C Ti (i=1-6) (see Table 5);

[0057] (2) According to the bottom flow limit concentration and supernatant turbidity of the tailings flocculation sedimentation test, calculate the tailings flocculation effect index W of each flocculant i =C Li / C Ui (i=1-6) (see Table 5);

[0058] (3) According to the tailings flocculation effect of each flocculant and the cost of the flocculant, calculate the cost performance of each flocculant. ci =W i / C Ti(i=1-6) (see Table 5);

[0059] (4) According to the implementation case of the present invention, a large iron mine in my country has a large demand for tailings for backfill mining. Therefore, the weight α of the cost-effectiveness of the tailings flocculation sedimentation rate is selected as 0.7, and the concentrator has a low requirement for the return water utilization rate, so the weight β of the cost-effectiveness of the tailings flocculation effect is selected as 0.3.

[0060] (5) According to the cost performance of tailings flocculation sedimentation rate and flocculation effect as well as the selected weights, calculate the cost performance of tailings flocculation index: Z ci =αV Xi +βX ci (i=1~6)(see Table 5).

[0061] Table 5 Results of flocculation and sedimentation test of graded fine tailings and calculation of flocculation effect index

[0062]

[0063] Step 6: Decision on the selection of flocculants for flocculating dense tailings and flocculating fine tailings

[0064] The cost performance of the six flocculants on the flocculation index of graded fine tailings is used as the flocculant selection decision indicator for graded fine tailings flocculation and dense filling. It can be seen from the calculation results of the cost performance of the flocculation index of graded fine tailings in Table 5 that: # Cost-effectiveness of flocculation index of Nour flocculant Z ci =2.1 is the highest, thus Nol flocculant is the best flocculant in this embodiment.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for selecting a flocculant to reduce the cost of graded fine tailings filling mining, characterized in that: Here are the steps: 1). Determine the mass concentration of the graded fine tailings slurry; sample the fine tailings for mineral composition and particle size analysis; select N types of flocculants suitable for the fine tailings, and prepare flocculant solutions with a tailings slurry mass concentration of 0.1% respectively; 2). Carry out flocculation and sedimentation tests of fine tailings slurry for each flocculant and tailings slurry concentration, and obtain the test data of flocculation and sedimentation time and sedimentation height of fine tailings slurry for each flocculant; 3). Using the polynomial regression analysis method, the experimental data of the flocculation sedimentation time and sedimentation height of the fine tail mortar were regressed and analyzed, thereby obtaining the sedimentation function of the fine tail mortar; 4). Take the derivative of the fine tail mortar sedimentation function and calculate the function value of its derivative function at the initial time, thereby obtaining the fine tail mortar flocculation sedimentation rate V i , where i = 1 to N; 5). Based on the cost of each flocculant C Ti , i = 1 ~ N, calculate the cost performance of each flocculant's fine tail slurry sedimentation rate: V Xi =V i / C Ti , i = 1 to N; where V i is the flocculation and settling rate of fine tail slurry of the i-th flocculant; 6). According to step 2), calculate the bottom flow limit concentration C of each flocculant fine tail slurry flocculation sedimentation Li and supernatant turbidity C Ui , i = 1 ~ N; the flocculation effect of fine tailing slurry is calculated from this: W i =C Li / C Ui ; 7). According to the flocculant cost C Ti , calculate the cost performance of fine tail slurry flocculation effect: X ci =W i / C Ti , i = 1 to N; 8). According to the demand for tailings usage in the scale of mine filling and mining, as well as the requirements for preparing high-concentration filling slurry and backwater utilization, the weight α of the cost-effectiveness of the settling rate of fine tailings slurry and the weight β of the cost-effectiveness of the flocculation effect are determined respectively; 9). According to steps 5), 7), and 8), calculate the cost performance of fine tail slurry flocculation index: Z ci =αC Xi +βX ci Among them, C Xi Represents the cost-effectiveness of fine tailing slurry flocculation and sedimentation rate, X ci Represents the cost-effectiveness of tailings slurry flocculation effect; 10). Select Z ci The flocculant corresponding to the maximum value is selected as the flocculant for the dense graded fine tailing mortar.

2. The method for selecting a flocculant for reducing the cost of graded fine tailings filling mining according to claim 1, characterized in that: In the step 1), a graded fine tail slurry flocculation and sedimentation test is performed on each flocculant to obtain the fine tail slurry flocculation and sedimentation time and sedimentation height test data of each flocculant: {(t1,h1), (t2,h2), ..., (t m ,h m )} i , i=1~N.

3. The method for selecting a flocculant for reducing the cost of graded fine tailings filling mining according to claim 1, characterized in that: In the step 3), the mortar underflow limit concentration is calculated according to the final settling time of the fine tail mortar flocculation sedimentation test; the underflow limit concentration calculation formula is as follows: Where: C 底流 ——underflow limit concentration, %; W 砂 ——Mass of tailings in fine tailings mortar, g; W 水 ——The mass of water in the mortar, g; ω 水 ——The mass of upper clarified water, g.

4. The method for selecting a flocculant for reducing the cost of graded fine tailings filling mining according to claim 1, characterized in that: In the step 4), the fine tailing mortar settlement function is derived, d[f i {(t1,h1),(t2,h2),…(t m ,h m )}]dt, i = 1 ~ N, take the derivative of its sedimentation function and find its function value at the initial time (t = 0), thus obtaining the fine tail slurry flocculation sedimentation rate V ni , i=1~N.

5. The method for selecting a flocculant for reducing the cost of graded fine tailings filling mining according to claim 1, characterized in that: In the step 8), the cost performance ratio of the fine tail slurry flocculation index is calculated according to α=0.7 and β=0.3: Z ci =αC Xi +βX ci ; Among them, C Xi Represents the cost-effectiveness of fine tailing slurry flocculation and sedimentation rate, X ci Represents the cost-effectiveness of fine tail mortar flocculation effect.

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