GB/T 15715-1995 Method for evaluating the process performance of coal gravity separation equipment
Some standard content:
National Standard of the People's Republic of China
Gravity separating equipment for coal-Performance evaluation
GB/T 15715-1995
This standard adopts ISO923:1975 "Coal preparation test-representation and explanation of results" of the International Organization for Standardization. 1 Subject content and scope of application
This standard specifies the evaluation indicators, data verification, curve drawing and form filling of the process performance of coal gravity separation equipment. This standard is applicable to the evaluation of the process performance of various gravity separation equipment in the heavy medium and water medium separation of coal. In principle, this standard is also applicable to the evaluation of the process performance of coal gravity separation equipment for gas medium. This standard is not applicable to the processing of monthly comprehensive data of coal preparation plants. 2 Reference standards
GB478 Coal floating and sinking test method
MT145 Computer algorithm for evaluating the process performance of coal preparation plant gravity separation equipment 3 Evaluation indicators
3.1 There are three indicators for evaluating the process performance of gravity separation equipment: a.
Possible deviation or imperfection;
b. Quantitative efficiency,
c. Total mismatch content
3.1.1 The calculation formulas for possible deviation (generally used for heavy medium separation) and imperfection (only used for water medium separation) are E
wherein: E—possible deviation, kg/L
—imperfection;
(875 — 825)
(875 - 825)
2(85. — 1)
grs—density corresponding to a distribution rate of 75% on the heavy product distribution curve, kg/L; 32s—density corresponding to a distribution rate of 25% on the heavy product distribution curve, kg/L; 3s.—density corresponding to a distribution rate of 50% on the heavy product distribution curve, kg/L, that is, distribution density, that is, separation density. 3.1.2 The formula for calculating the quantitative efficiency is:
Approved by the State Administration of Technical Supervision on October 17, 1995×100
·(2)
Implemented on June 1, 1996
Where: ——numerical efficiency, %;
Y——clean coal yield, %;
GB/T 15715—1995
Yu-——theoretical clean coal yield, %, the value of which is obtained from the selectivity curve of the calculated feed. 3.1.3 The formula for calculating the total mismatch basis is:
Total mismatch basis (percentage of feed), %:
Where: ma
-the mismatch amount of materials with a density less than the sorting density in the heavy product (percentage of feed), %; m
-the mismatch amount of materials with a density greater than the sorting density in the light product (percentage of feed), %. 3.2 Principles of index application
. (4)
3.2.1 The first and second indexes should be calculated for the identification of newly developed equipment, the acceptance of newly put into production equipment or important production technology inspections. 3.2.2 The third index is an index selected as needed. 3.2.3 The indexes used in daily production inspections and evaluations are not restricted by this standard. 3.3 Calculation of indexes
3.3.1 The calculation of various process performance indexes should be processed by computer as much as possible according to MT145. 3.3.2--Generally only the whole particle size is calculated. If necessary, each particle size can be calculated separately. 3.3.3 The lower limit of sorting--generally can be calculated as 0.5mm, or it can be taken according to the specific situation of the equipment. 3.3.4 For multi-stage sorting, each stage can be regarded as a separate sorting process, each with its own calculated feed. Draw the distribution curve and mismatch curve for each stage.
3.3.5 The yield of the sorted products should be determined by the full amount measurement method as much as possible; it can also be calculated according to the method provided in Appendix A. 3.3.6 The principle of taking significant figures is: the quantities in percentage units are rounded to the second decimal place; other quantities can be rounded to two or three decimal places depending on the data accuracy and calculation accuracy. 4 Data verification
4.1 The collection of data used in the calculation should be based on the current national standards such as sampling, coal sample reduction, screening test, floating and sinking test and ash determination. 4.2 After determining the product yield, the mean square error of the yield of each density grade of the calculated feed and the actual feed should be calculated according to the following formula: 1
Where: a-
mean square error;
density grade during the floating and sinking test;
number of sorted products:
S(Go,
yG/100
G-calculated yield of the jth density level in the feed, %; Ga
-actual yield of the ith density level in the feed, %; Gu
-yield of the first density level in the first product, %:,-yield of the ith product, %; product numbers are arranged from small to large according to ash content. In order to verify the reliability of the original data, the mean square error should not exceed the critical value. The critical value is selected as follows: a
For jigging primary selection and heavy medium primary selection, the critical value is generally taken as 1.4; b.
For jigging reselection and heavy medium reselection, the above critical value can be appropriately tightened; for large block discharge or For feed materials with serious mud separation, the above critical value can be appropriately relaxed; c.
In some cases, the critical value can also be agreed upon by the delivery parties in the technical documents, d.
(5)
4.3 After completing the calculation of the distribution rate of each density level and synthesizing the calculated feed, the calculated data should be checked. When the following situations are found, the original data submitted for calculation can be judged as unqualified. a.
The calculated result of product yield is negative; the mean square error of the calculated feed and the actual feed yield of each density level exceeds the critical value specified in Article 4.2. b.
The average ash content of each density level of the calculated feed cannot form an increasing sequence according to the average density; c.
The distribution rate of heavy products of each density level except the end cannot form a monotonically non-decreasing sequence according to the average density; d.
There are less than 6 data points of distribution rate;
There are less than 2 data points with a distribution rate greater than 50% or less than 2 data points with a distribution rate less than 50%; f.
There is no data point with a distribution rate greater than 75% or no data point with a distribution rate less than 25%. g.
4.4 When the situations listed in a~d of Article 4.3 occur, if there are two adjacent density levels of calculated feed and actual If the yield deviation of the actual feed material has opposite signs and the absolute value is greater than 2, it is allowed to merge the two density levels and recalculate, but the recalculated result should still meet the requirements of Article 4.3.
5 Curve drawingwwW.bzxz.Net
5.1 Distribution curve
5.1.1 Calculation of distribution rate
5.1.1.1 The distribution rate is calculated by calculating the distribution of the feed material in the heavy product. 5.1.1.2 For the sorting equipment that separates M kinds of products (the product sequence numbers are arranged according to the provisions of Article 4.2), there are a total of (M-1) sorting sections. If the heavy product is separated section by section, the heavy product distribution rate of each section is calculated as follows: Pk:
G- × 00k = ,.,M -- ; = 1,2,N)MYG
Wherein: P,-the distribution rate of heavy products of the i-th density level in the k-th section, %; Y.,Y,—-the yield of the i-th or s-th product, %, (i=1,2,..,ss-M-k+1); Gi,i-the yield of the j-th density level in the i-th or s-th product of the product, %. 5.1.1.3 For equipment that separates light products in stages, the distribution rate of heavy products in each stage is calculated as follows: u
P, -
- X 100(k - 1,2..,M - 1,j- 1,2,...,N) 5.1.2 Drawing of distribution curve
.....(8)
5.1.2.1 The distribution curve is drawn in arithmetic coordinates. The horizontal coordinate of each data point is the average density of each density level, and the vertical coordinate is the distribution rate of each density level material in the heavy product (see Table D4). The scale ratio of the two coordinate axes is preferably such that 0.1 kg/L density corresponds to a distribution rate of 10% to 20%.
5.1.2.2 The average density of each density level, as well as the density of the lowest density material and the highest density material can be determined by referring to MT145. When the distribution curve is processed manually, the above densities can also be taken as empirical values. 5.1.2.3 The distribution curve is drawn according to the principle of minimizing the sum of the squares of the distances from the data points to the curve in the ordinate direction, and should maintain a smooth S-shaped state (see Figure D1).
5.2 Selectivity curve
5.2.1 The selectivity curve used to calculate the process performance index is drawn based on the selectivity data of the calculated input material. 5.2.2 The type of selectivity curve can be selected from the following two groups: a.Mayer curve (M curve) and density curve (curve); b. Floating matter accumulation curve (β curve) and density curve (curve). 5.2.3 The horizontal coordinate of the M curve is the accumulated ash content of floating matter, and the vertical coordinate is the corresponding accumulated yield of floating matter (see Table D6 and Figure D2). 5.2.4 The curve and β curve can be drawn with reference to Appendix A of GB478. 399
5.3 Mismatch curve
GB/T15715—1995
5.3.1 The mismatch amount is calculated as a percentage of the calculated input material. 5.3.2 The mismatch curve includes the loss curve, the contamination curve and the total mismatch content curve formed by the superposition of these two curves. 5.3.3 The horizontal coordinate of the loss curve is density, and the vertical coordinate is the accumulated yield of floating matter in the heavy product corresponding to each density as a percentage of the calculated input material (see Table D7 and Table D8).
5.3.4 The contamination curve and the loss curve use the same horizontal coordinate, and the vertical coordinate is the cumulative yield of the sediment corresponding to each density in the light product as a percentage of the calculated input material (see Table D7 and Table D8).
5.3.5 The intersection of the loss curve and the contamination curve corresponds to the equal mismatch density. The lowest point of the total mismatch content curve corresponds to the distribution density (see Figure D3 and Figure D4).
6 Filling in the form
6.1 The basic format of the process performance evaluation report form is shown in Appendix B. For non-three-product sorting, the content of Appendix B can be appropriately increased or decreased according to the number of products.
6.2 The remarks part of the evaluation report form can refer to Appendix C to fill in the factors affecting the process performance, such as the nature of the input material, equipment characteristics and operation management, as needed.
6.3 The format of the data calculation table can refer to Appendix D Table D2 to Table D8. 400
A1 General algorithm
GB/T 15715---1995
Appendix A
Algorithm for the yield of sorted products
(Supplement)
The problem of calculating the yield of sorted products can be expressed as an optimization problem, that is, the objective function"(Go,
y,G;,/100) \ = Min
Constraints
Where: M—the number of sorted products; N—the density level of the floating and sinking tests on the feed and product; Go,—the yield of the i-th density in the actual feed, %; 100
G—the yield of the i-th density level in the i-th product, %. （A1）
（A2）
Where the product numbers are arranged from small to large according to the ash content, i=1 represents clean coal, =M represents ground stone, and the rest represent medium coal or intermediate products.
—The yield of the i-th product, %.
Using the Lagrange multiplier method, (A1) and (A2) can be transformed into an unconstrained optimization problem. N
Where: I-
Lagrange multiplier.
Introduce the vector expression of the unknown number
Zr,Gi,/100)\ + A( >
- 100) = Min
（A3）
.（A4)
100100
Take the partial derivatives of the left and right ends of (A3) with respect to the elements of vector X and set them to zero, and we get a linear equation system of M plus 1 order, whose matrix expression is
In the formula, the elements of the coefficient matrix A are
2G,G,(1≤≤M and 1≤ig12 and g22 are calculated as follows:gor
(Go, G3,)(Gj — G3,)
- G3,)(G2j G3,)
G3;)(G2; - G3,)
An example of calculating the product yield of three-product separation is given in Appendix D. 402
（A10）
（A1)
·(A12 )
（A13）
（A14）
（A15）
·(A16 )
.(A17 )
...(A19)
Test No.
Equipment model and specification
Feed coal type
Feed particle size.mm
Feed ash content, %
Operation nature
Processing capacity, t/h
Test duration, h
Equipment type
Jig
Coal preparation trough
Cyclone
Heavy medium separator
Channel separator
Spiral separator
GB/T 15715--1995
Appendix B
Report Form for Evaluation of Process Performance of Gravity Separation Equipment
(reference)
Test Location
Separated Products, %
Yield Ash Content
Yield Ash Content
Mean Square Deviation
Yield Ash Content
Separated Density, kg/L
Appendix C
Factors Affecting Process Performance
(reference)
Feed Properties
Coal Type, Particle Size Composition, Density Composition,
Shape, Hardness, Mudification Characteristics
Coal Type, Particle Size Composition, Density Composition,||tt ||Shape, hardness, mud properties
Coal type, particle size composition, density composition,
Shape, hardness, mud properties
Coal type, particle size composition, density composition,
Shape, hardness, mud properties
Coal type, particle size composition, density composition,
Shape, hardness, mud properties
Coal type, particle size composition, density composition,
Shape, hardness, mud properties
Coal type, particle size composition, density composition,
Shape, hardness, mud properties
Test date
Calculation of feed selectivity
Theoretical clean coal yield, %||tt| |Theoretical sorting density, kg/l
±0.1Content, %
Sorting effect
Possible deviation (E), kg/L
Imperfection (I)
Quantitative efficiency (n), %
Total error under distribution density
Material content (mo), %
Equal error density, kg/L
Equipment characteristics
Structural characteristics, screen plate inclination, screen hole
Shape and size, artificial bed configuration
, discharge method, air valve form
Structural characteristics, trough box size, each section
Inclination, discharge method
Structure Characteristics, stroke, number of strokes, bed surface material and inclination, bed bar height range, centrifugal strength, structural characteristics, inlet size, center tube diameter and insertion depth, underflow port size, cone angle, installation angle, structural characteristics, suspension flow direction, structural characteristics, installation angle, partition size, installation height and spacing, discharge method, cross-sectional shape, lateral inclination, number of figures, number of slot heads, slot surface material, pitch straightness Note: 1) For heavy medium cyclones, the relevant factors in the operation and management column of the heavy medium separator should also be considered. Operation management
Feeding conditions, water supply method, washing water
dosage, water supply concentration, wind pressure, cycle
Feeding conditions, water supply method, washing water
dosage, water supply concentration
Feeding conditions, water supply method, washing water
dosage, water supply concentration
Medium concentration, feed concentration, feed
pressure\
Type and particle size of weighting material, suspension
liquid density and viscosity, density control method
method, medium Mass circulation
Feeding conditions, washing water concentration, washing water
pressure, washing water dosage, water supply method
Feeding concentration, feeding amount, feeding method
formula, interceptor position
GB/T15715--1995
Appendix D
Process performance calculation example
(reference)
D1 The basic situation of the industrial test of a jigger is shown in the overview column of Table D1, and Table D2 is the density analysis results of the feed and product. D2 The yield of the sorted product is obtained by solving the linear equation group (A5) formula according to the method provided in Chapter A1 of Appendix A. It is also possible to use manual calculation to obtain the values of gol>g11, gozvg12 and g22 from Table D3 and substitute them into (A12) (A14) formulas for calculation. Fill in the yield of each product in Table D1.
D3 The calculation of distribution rate and mean square error is shown in Table D4. The mean square error is calculated according to formula (5) and filled in Table D1. Data verification is carried out according to the requirements of Article 4.3, and the original data is deemed valid.
D4 The synthetic process of the calculated feed and its selectivity data are shown in Table D5 and Table D6. D5 Table D7 and Table D8 are respectively the calculation of the mismatch amount of the two sorting sections. For the second section, it should be noted that the yield of the product of this section to the feed of this section should be calculated (see columns (59) and (60) of Table D8). D6 The distribution curve of the first section is drawn based on the data of columns (26) and (27) of Table D4, and the distribution curve of the second section is drawn based on the data of columns (26) and (28) of Table D4 (see Figure D1). The sorting density 85. and imperfection 1 of the two sections are obtained from the distribution curves respectively, and they are filled in Table D1.
D7 The selectivity curve (Figure D2) is drawn based on the data in Table D6. The horizontal coordinate of the M curve is the data in column (43) (see the bottom of the figure), and the horizontal coordinate of the curve is the data in column (41) (see the top of the figure). Their vertical coordinates are all the data in column (42). The theoretical clean coal yield, theoretical sorting density and ±0.1 content under the theoretical sorting density are read from the selectivity curve and filled into Table D1. D8 The mismatch curve is drawn for two sorting sections. Figure D3 is the mismatch curve of the first section, and the coordinate values of its data points are from Table D7. The horizontal coordinates of the three curves all correspond to the data in column (52), the vertical coordinate of the contamination curve is the data in column (53), the vertical coordinate of the loss curve is the data in column (54), and the vertical coordinate of the total mismatch content curve is the data in column (55). The mismatch curve of the second section is shown in Figure D4, in which the horizontal coordinates of the three curves all correspond to the data in column (61) of Table D8. The vertical coordinates of the three curves are taken from the data in columns (62), (63) and (64) of Table 8 respectively. Read the total mismatch content and equal mismatch density under the distribution density of each sorting section from the two mismatch curves and fill in Table D1.
D9 Fill in the remaining items in the process performance evaluation report form (Table D1). 404
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