A method for determining reasonable concentrate grade in magnetic separation-fine screening and regrinding process

Abstract

The present invention relates to a method for determining a reasonable concentrate grade in a magnetic separation-fine screening regrinding process, which is characterized by comprising the following steps: firstly, under the condition that the mth concentrate grade product is obtained in the process flow, by determining the utilization coefficient q of each mill stage n And calculate the feed rate γ of each grinding and classification operation n , calculate the comprehensive utilization coefficient of the mill q 综m ; Then, the grinding cost C corresponding to the known production cost C1 is 磨1 and mill comprehensive utilization coefficient q 综1 As a benchmark, the mth concentrate grade product will be obtained when q 综m Value and q 综1 Compare and calculate the grinding cost C corresponding to the mth concentrate grade product 磨m ; Finally, the profit difference ΔR between the production of the mth concentrate grade product and the first concentrate grade product is calculated, and the reasonable concentrate grade is determined accordingly. The advantages of the present invention are: predicting the reasonable concentrate grade in advance is conducive to decision-making and guiding production, reducing costs, and improving economic benefits and market competitiveness.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing technology, and in particular relates to a method for determining a reasonable concentrate grade in a magnetic separation process. Background Art

[0002] At present, the ore dressing plants that mainly process lean magnetite usually adopt stage grinding and single magnetic separation process for production. The more common application is the production process of stage grinding, stage magnetic separation, fine screening and re-grinding. For a long time, due to the low grade of iron concentrate being the main problem, the ore dressing plants have tried every means to implement the policy of "increasing iron and reducing silicon", and have only pursued high-grade concentrates. They have not organically combined the grade of iron concentrate with the cost of ore dressing, and have not rationally and effectively developed resources. This is also an important reason for the high cost and low competitiveness of iron concentrate in the ore dressing plants. The grinding capacity of the ore dressing plant determines the production capacity of the ore dressing plant. The quality of the grinding effect, that is, the degree of dissociation of useful mineral monomers in the grinding product, determines the technical indicators of the iron concentrate of the ore dressing plant. The grinding operation cost is the most expensive operation in the process of stage grinding, stage magnetic separation, and fine screening and re-grinding. Therefore, the grinding cost is directly related to the grade of iron concentrate and the production capacity and production cost of the ore dressing plant. Therefore, based on the grinding cost, by establishing the functional relationship between the products of different concentrate grades and the cost of the ore dressing plant, and then evaluating the reasonable concentrate grade of the ore dressing plant, it will help the ore dressing plant to make decisions, reduce production costs, and improve economic benefits and market competitiveness. Summary of the invention

[0003] The purpose of the present invention is to provide a method for determining a reasonable concentrate grade in a magnetic separation-fine screening and regrinding process. The present invention establishes a relationship model between the iron concentrate grade and the ore dressing production cost, which is used to evaluate the reasonable concentrate grade of the ore dressing process, provide guidance for the optimization of ore dressing production, reduce production costs, and improve the economic benefits and market competitiveness of the ore dressing plant.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] The method for determining the reasonable concentrate grade of a magnetic separation-fine screening and regrinding process of the present invention is characterized by comprising the following steps:

[0006] Step 1: First, under the condition that the mth concentrate grade product is obtained in the process flow, the utilization coefficient q of each mill is calculated by measuring the feed particle size and product particle size of each grinding and classification operation in the process flow. n ; Then, the feed rate γ of each grinding and classification operation is calculated by measuring the grade of each product in the process flow n , where n is the number of grinding stages, n = 1, 2, 3; finally, formula (1) is used to calculate the value of q n and γ n The corresponding mill comprehensive utilization coefficient q 综m :

[0007]

[0008] q 综m The comprehensive utilization coefficient of the mill when obtaining the mth concentrate grade product, T / m 3 h, m are natural numbers ≥ 1.

[0009] Step 2: Corresponding grinding cost C1 of the first concentrate grade product with known production cost C 磨1 and mill comprehensive utilization coefficient q 综1 As a benchmark, the mth concentrate grade product will be obtained when q 综m Value and q 综1 Compare and calculate the grinding cost C corresponding to the mth concentrate grade product in production 磨m .

[0010] Grinding cost C 磨m Use formula (2) for calculation:

[0011]

[0012] Where: i m It is the mineral processing ratio for obtaining the mth concentrate grade product.

[0013] Step 3: Use the known production cost C1 to calculate the production cost C1 of the first concentrate grade product when obtaining the mth concentrate grade product in production. m .

[0014] Production cost m Formula (3) is used to calculate the cost of raw ore and grinding cost:

[0015] C m =C1-i1S 原 -C 磨1 +i m S 原 +C 磨m (3)

[0016] Where: S 原 is the price of raw ore, Yuan / ton.

[0017] Step 4: Calculate the profit difference ΔR between the mth concentrate grade product and the first concentrate grade product obtained in the process flow to determine the reasonable concentrate grade.

[0018] The profit difference ΔR is calculated using formula (4):

[0019]

[0020] If ΔR>0, it is reasonable to change the concentrate grade; if ΔR<0, it is unreasonable to change the concentrate grade.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] The production capacity of the ore dressing plant is determined by the grinding capacity, the quality of the grinding effect determines the technical indicators of the iron concentrate products of the ore dressing plant, and the level of the grinding cost directly determines the production cost of the ore dressing plant. The present invention is based on the grinding cost when obtaining products of different concentrate grades, establishes a functional relationship between the production cost of the ore dressing plant and the concentrate grade, and then evaluates the reasonable concentrate grade of the ore dressing plant, which is helpful for the ore dressing plant to make production decisions, reduce production costs, and improve economic benefits and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a flow chart of the principle of the magnetic separation-fine screening regrinding process of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0025] First, let me introduce the relevant concepts:

[0026] The utilization factor of the mill is q n : The amount of newly generated -200 mesh ore per unit time and per unit mill volume, T / m 3 ·h.

[0027] Example

[0028] like Figure 1 As shown, this embodiment compares product solutions of different concentrate grades based on the process flow of stage grinding, stage magnetic separation, fine screening and regrinding.

[0029] It is known that when the final concentrate grade is 66.40%, the production cost (base m=1) is 413.84 yuan / ton of concentrate. Calculate the production cost when the final concentrate grade is 67.89% (m=2), and evaluate the rationality of its concentrate grade.

[0030] Step 1

[0031] 1) Given the production cost, the benchmark m = 1:

[0032] When the concentrate grade is 66.40%, the utilization coefficients of each mill are: Utilization coefficient of mill 1 = 0.383 T / m 3 h, Second stage mill utilization coefficient q2 = 0.162T / m 3 h, three-stage mill utilization coefficient q3 = 0.147T / m 3h, the feed rate of each stage of grinding and classification operation is: the feed rate of the first stage mill is γ1 = 100%, the feed rate of the second stage mill is γ2 = 49.42%, and the feed rate of the third stage mill is γ3 = 8.38%.

[0033] Mill comprehensive utilization coefficient q 综m Calculate using formula (1):

[0034]

[0035] Calculate the comprehensive utilization coefficient of the mill q 综1 =0.1605T / m 3 ·h.

[0036] 2) Unknown production cost, m = 2:

[0037] When the concentrate grade is 67.89%, the utilization coefficients of each mill are: Utilization coefficient of mill q1 = 0.382T / m 3 h, Second stage mill utilization coefficient q2 = 0.131T / m 3 h, three-stage mill utilization coefficient q3 = 0.127T / m 3 h, the feed rate of each stage of grinding and classification operation is: the feed rate of the first stage mill is γ1 = 100%, the feed rate of the second stage mill is γ2 = 47.56%, and the feed rate of the third stage mill is γ3 = 7.15%.

[0038] Calculate the comprehensive utilization coefficient of the mill q 综2 =0.1468T / m 3 ·h.

[0039] Step 2: Grinding cost C when the final concentrate is 66.40% 磨1 = 65 yuan / ton of concentrate, comprehensive utilization coefficient of mill q 综1 =0.1605T / m 3 ·h, dressing ratio i1=3.0160.

[0040] When the concentrate grade is 67.89%, the comprehensive utilization coefficient of the mill is q 综2 =0.1468T / m 3 ·h, dressing ratio i2 = 3.1383.

[0041] Calculate using formula (2):

[0042]

[0043] Calculated grinding cost C 磨2 =74 yuan / ton of concentrate.

[0044] Step 3: When the final concentrate is 66.40%, the production cost C1 = 415 yuan / ton of concentrate, and the price of raw ore is calculated at 85 yuan / ton of raw ore, and the calculation is performed using formula (3):

[0045] C2=C1-i1S 原 -C 磨1 +i2S 原 +C 磨2 (3)

[0046] The production cost C2 is calculated to be 434.40 yuan / ton of concentrate when the concentrate grade is 67.89%.

[0047] Step 4: When the product with a concentrate grade of 67.89% is obtained, the product price is 740 yuan, and when the final concentrate grade is 66.40%, the product price is 710 yuan. Calculate using formula (4):

[0048]

[0049] The profit difference ΔR is calculated to be -26.38 yuan, ΔR≤0, and the conclusion is that it is more reasonable to produce products with a concentrate grade of 66.40%.

[0050] By analogy, we can also calculate the comprehensive utilization coefficient q of different mills such as m=3, m=4, etc. 综m , and q 综1 By making comparisons and performing subsequent calculations in steps, the production costs of the process flow of stage grinding, stage magnetic separation, fine screening and regrinding can be predicted to guide on-site production and reasonably determine the grade of concentrate, thus reducing the production costs of enterprises and improving their economic benefits and competitiveness.

Claims

1. A method for determining the reasonable concentrate grade of a magnetic separation-fine screening and regrinding process, characterized in that The following steps are involved: Step 1: First, under the condition that the mth concentrate grade product is obtained in the process flow, the utilization coefficient q of each mill is calculated by measuring the feed particle size and product particle size of each grinding and classification operation in the process flow. n ; Then, the feed rate γ of each grinding and classification operation is calculated by measuring the grade of each product in the process flow n , where n is the number of grinding stages, n = 1, 2, 3; finally, formula (1) is used to calculate the value of q n and γ n The corresponding mill comprehensive utilization coefficient q 综m : q 综m The comprehensive utilization coefficient of the mill when obtaining the mth concentrate grade product, in tons / cubic meter·hour, where m is a natural number ≥ 1; Step 2: Corresponding grinding cost C1 of the first concentrate grade product with known production cost C 磨1 and mill comprehensive utilization coefficient q 综1 As a benchmark, the mth concentrate grade product will be obtained when q 综m Value and q 综1 Compare and calculate the grinding cost C corresponding to the mth concentrate grade product in production 磨m ; Step 3: Use the known production cost C1 to calculate the production cost C1 of the first concentrate grade product when obtaining the mth concentrate grade product in production. m ; Step 4: Calculate the profit difference ΔR between the mth concentrate grade product and the first concentrate grade product obtained in the process flow to determine the reasonable concentrate grade; the profit difference ΔR is calculated using formula (4): If ΔR>0, it is reasonable to change the concentrate grade; if ΔR<0, it is unreasonable to change the concentrate grade.

2. The method for determining the reasonable concentrate grade of the magnetic separation-fine screening and regrinding process according to claim 1 is characterized in that: In step 2, the grinding cost C 磨m Use formula (2) for calculation: Where: i m It is the mineral processing ratio for obtaining the mth concentrate grade product.

3. The method for determining the reasonable concentrate grade of the magnetic separation-fine screening and regrinding process according to claim 1 is characterized in that: In step 3, the production cost C m Formula (3) is used to calculate the cost of raw ore and grinding cost: C m =C1-i1S 原 -C 磨1 +i m S 原 +C 磨m (3) Where: S 原 is the price of raw ore, Yuan / ton.

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