CN104774011A - Method for determining reasonability of theoretic formula granularity composition of graphite electrode - Google Patents

Abstract

The invention relates to a method for determining the reasonability of the theoretic formula granularity composition of a graphite electrode. The method is characterized in that the reasonability of the theoretic formula granularity composition of the graphite electrode is determined according to an R value obtained through using an equation shown in the specification, the critical point of the R value is 0.809, and the theoretic formula granularity composition is reasonable when R is not lower than 0.809, so the formula can be used in the production of the graphite electrode; and when R is smaller than 0.809, the theoretic formula granularity composition is unreasonable, so the formula cannot be used in the production of the graphite electrode. The method has the advantages of scientificity, reasonability, high practical application value, simplicity, easy implementation and substantial effect.

Description

The rational defining method of a kind of Graphite Electrodes theory formula size composition

Technical field

The present invention is the rational defining method of a kind of Graphite Electrodes theory formula size composition.

Background technology

Graphite Electrodes formula is divided into theoretical formula and production formula, and theoretical formula is also referred to as technical requirements, and production formula is also referred to as lower material formula (the cutting stock weight kilogram number of various raw material and grade).Theoretical formula is the core of production formula, is the technical regulation that establishment production formula must be observed.The content of theoretical formula comprises the aspects such as proportioning raw materials, size composition, powder purity and bituminous cement ratio.In theory formula, its size composition is key factor, it is in fact the technical controlling for main particle size rank weight percent in the material composition of Graphite Electrodes, the per-cent normally controlling powder per-cent and macrobead grade will meet technical requirements, does not specify technical requirements for other secondary grade per-cent.Reason is, in charcoal element is produced, the purity of particulate material and powder purity are fluctuations, cannot ensure in the constant situation of feed purity, carry out particulate material fragmentation and abrasive dust.Therefore, for the Graphite Electrodes of specifying specification and lot number, theoretical formula is changeless, and production formula is unfixed, can adjust in time according to the change of feed purity, with the technical regulation requirement of satisfied theory formula.Therefore theoretical formula determines the weave construction of graphite electrode material, and the size composition of theoretical formula is the key element ensureing Graphite Electrodes quality product.The Graphite Electrodes of different size and lot number has different theory formulas and size composition.Use properties requirement in order to make Graphite Electrodes meet electric-arc furnace steelmaking in production, for different capacity of electric arc furnace, transformer power input, current density and smelting condition, require the theory formula redesigning and adjust Graphite Electrodes, its material rate of main adjustment and size composition, and the adjustment of size composition and determine it is very difficult thing, it needs technician to have long-term knowhow accumulation and the abundant understanding for electrode use properties, again through the practical application of charcoal element production, continuous adjustment, the inspection of testing that improves and make steel could progressively be decided.When the size composition of theory formula has reasonableness, qualified carbonaceous product will be produced, otherwise, underproof product or second-rate product will be produced.

For the deterministic process of theory formula size composition, quite very long in general, need 1 to two year, even the time of 3 to four years could be decided gradually.Size composition unreasonable will causing produces a large amount of waste product, reduces quality product, increases enterprise's production cost; When size composition has reasonableness, the measured product of matter will be produced, improve the quality of products.Do not see the bibliographical information about Graphite Electrodes theory formula size composition reasonableness defining method and practical application so far.

Summary of the invention

The object of the invention is, provide a kind of scientific and reasonable, actual application value is high, simple and easy to do, and can realize the rational defining method of Graphite Electrodes theory formula size composition by calculating.

The technical scheme realizing the object of the invention employing is, the rational defining method of a kind of Graphite Electrodes theory formula size composition, and it is characterized in that, it has in comprising:

1) granularity level of Graphite Electrodes theory formula is according to the size of screen cloth mesh size, be expressed as, "-" number is added before the mesh size millimeter of upper sieve, add "+" number before the mesh millimeter of lower screen, represent that material grade is less than upper sieve mesh size, is greater than lower screen hole dimension, for the material grade that bottom one deck screen cloth passes through, add "-" number with before screen cloth mesh millimeter, the proportion of composing of each grade represents with weight percent;

2) calculating of theoretical formula size composition reasonableness R value, using the upper sieve mesh size millimeter of each grade as independent variable(s), represents with X, the weight percentage composition being less than or equal to upper sieve mesh of each grade is carried out cumulative addition, as dependent variable, represent with Y, obtain one group of data pair about X and Y, the value that data are right represents with Xi and Yi, the number that data are right represents with n, i=1,2,, n;

3) Graphite Electrodes theory formula size composition reasonableness is determined by following formula according to R value:

$R=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{X}_i{Y}_i-\frac{1}{n}\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{X}_i\right)\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{Y}_i\right)}{\sqrt{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{Y_i}^2-\frac{1}{n}{\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{X}_i\right)}^2}\·\sqrt{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{Y_i}^2-\frac{1}{n}{\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{Y}_i\right)}^2}}$

Stagnation point=(1+0.618) ÷ 2=0.809 of R value, when R >=0.809, the size composition of theoretical formula has reasonableness, can be used in Graphite Electrodes and produces; As R < 0.809, the size composition of theoretical formula does not have reasonableness, can not be used for Graphite Electrodes and produce.

The rational defining method of a kind of Graphite Electrodes theory formula size composition of the present invention, owing to adopting the reasonableness of R value calculating method determination Graphite Electrodes theory formula size composition, eliminate the impact of human factor and multiple objective factor, avoid the Graphite Electrodes theory formula size composition caused for lacking experience due to people not there is the cost that reasonableness causes to increase and financial loss, there is methodological science reasonable, actual application value is high, simple and easy to do, the advantages such as Be very effective, the theory of Graphite Electrodes formula size composition reasonableness is made to determine more scientific and reasonable.

Embodiment

The rational defining method of a kind of Graphite Electrodes theory formula size composition of the present invention, it has in comprising:

1) granularity level of Graphite Electrodes theory formula is according to the size of screen cloth mesh size, be expressed as, "-" number is added before the mesh size millimeter of upper sieve, add "+" number before the mesh millimeter of lower screen, represent that material grade is less than upper sieve mesh size, is greater than lower screen hole dimension, for the material grade that bottom one deck screen cloth passes through, add "-" number with before screen cloth mesh millimeter, the proportion of composing of each grade represents with weight percent.

2) calculating of theoretical formula size composition reasonableness R value, using the upper sieve mesh size millimeter of each grade as independent variable(s), represents with X, the weight percentage composition being less than or equal to upper sieve mesh of each grade is carried out cumulative addition, as dependent variable, represent with Y, obtain one group of data pair about X and Y, the value that data are right represents with Xi and Yi, the number that data are right represents with n, i=1,2,, n.

3) Graphite Electrodes theory formula size composition reasonableness is determined by following formula according to R value:

$R=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X}_i{Y}_i-\frac{1}{n}\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X}_i\right)\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y}_i\right)}{\sqrt{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y_i}^2-\frac{1}{n}{\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X}_i\right)}^2}\&CenterDot;\sqrt{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y_i}^2-\frac{1}{n}{\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y}_i\right)}^2}}$

Stagnation point=(1+0.618) ÷ 2=0.809 of R value, when R >=0.809, the size composition of theoretical formula has reasonableness, can be used in Graphite Electrodes and produces; As R < 0.809, the size composition of theoretical formula does not have reasonableness, can not be used for Graphite Electrodes and produce.

Example 1:

The size composition of table 1 φ 333CJ joint formula

Grade	mm	－2+1	－1+0.5	－0.5	－0.075
						Weight percent	％	13±2	17±2	70±3	54±3

Size composition is rewritten as cumulative percent by weight form by table 2

Independent variable(s) X	Upper size	mm	2	1	0.5	0.075
							Dependent variable Y	Cumulative percent by weight	％	100	87	70	54
Data are to i	i＝1,2,……,n	—	1	2	3	4

Wherein: i=1,2 ..., n; N=4;

X ₁＝2，X ₂＝1，X ₃＝0.5，X ₄＝0.075；Y ₁＝100，Y ₂＝87，Y ₃＝70，Y ₄＝54。

Calculate according to R value:

$R=\frac{326.050-\frac{1}{4}\&times;3.575\&times;311}{\sqrt{5.256-\frac{1}{4}\&times;{3.575}^2}\&CenterDot;\sqrt{25385-\frac{1}{4}\&times;{311}^2}}=0.9652$

Theoretical formula size composition reasonableness is determined: due to R=0.9652 > 0.809, Graphite Electrodes size composition has reasonableness.

Example 2:

Table 3 φ 450FG fills a prescription size composition

Grade	mm	－8+4	－4+2	－0.15	－0.075
						Weight percent	％	12±2	15±2	47±3	32±3

Size composition is rewritten as cumulative percent by weight form by table 4

Independent variable(s) X	Upper size	mm	8	4	0.15	0.075
							Dependent variable Y	Cumulative percent by weight	％	100	88	47	32
Data are to i	i＝1,2,……,n	—	1	2	3	4

Wherein: i=1,2 ..., n; N=4;

X ₁＝8，X ₂＝4，X ₃＝0.15，X ₄＝0.075；Y ₁＝100，Y ₂＝88，Y ₃＝47，Y ₄＝32。

Calculate according to R value:

$R=\frac{1161.450-\frac{1}{4}\&times;12.225\&times;267}{\sqrt{80.028-\frac{1}{4}\&times;{12.225}^2}\&CenterDot;\sqrt{20977-\frac{1}{4}\&times;{267}^2}}=0.9415$

Theoretical formula size composition reasonableness is determined: due to R=0.9415 > 0.809, Graphite Electrodes size composition has reasonableness.

Example 3:

The size composition of table 5 φ 550 short route formula

Grade	mm	－12+8	－8+4	－0.5	－0.075
						Weight percent	％	10±2	6±2	45±3	25±3

Size composition is rewritten as cumulative percent by weight form by table 6

Independent variable(s) X	Upper size	mm	12	8	0.5	0.075
							Dependent variable Y	Cumulative percent by weight	％	100	90	45	25
Data are to i	i＝1,2,……,n	—	1	2	3	4

Wherein: i=1,2 ..., n; N=4;

X ₁＝12，X ₂＝8，X ₃＝0.5，X ₄＝0.075；Y ₁＝100，Y ₂＝90，Y ₃＝45，Y ₄＝25。

Calculate according to R value:

$R=\frac{1944.375-\frac{1}{4}\&times;20.575\&times;260}{\sqrt{208.256-\frac{1}{4}\&times;{20.575}^2}\&CenterDot;\sqrt{20750-\frac{1}{4}\&times;{260}^2}}=0.9666$

Theoretical formula size composition reasonableness is determined: due to R=0.9666 > 0.809, Graphite Electrodes size composition has reasonableness.

Example 4:

The size composition of table 7 φ 400HP short route formula

Grade	mm	－6+4	－4+2	－0.15	－0.075
						Weight percent	％	12±2	12±2	60±3	45±3

Size composition is rewritten as cumulative percent by weight form by table 8

Independent variable(s) X	Upper size	mm	6	4	0.15	0.075
							Dependent variable Y	Cumulative percent by weight	％	100	88	60	45
Data are to i	i＝1,2,……,n	—	1	2	3	4

Wherein: i=1,2 ..., n; N=4;

X ₁＝6，X ₂＝4，X ₃＝0.15，X ₄＝0.075；Y ₁＝100，Y ₂＝88，Y ₃＝60，Y ₄＝45。

Calculate according to R value:

$R=\frac{964.375-\frac{1}{4}\&times;10.225\&times;293}{\sqrt{52.028-\frac{1}{4}\&times;{10.255}^2}\&CenterDot;\sqrt{23369-\frac{1}{4}\&times;{293}^2}}=0.9694$

Theoretical formula size composition reasonableness is determined: due to R=0.9694 > 0.809, Graphite Electrodes size composition has reasonableness.

Claims (1)

1. the rational defining method of Graphite Electrodes theory formula size composition, it is characterized in that, it has in comprising:

1) granularity level of Graphite Electrodes theory formula is according to the size of screen cloth mesh size, be expressed as, "-" number is added before the mesh size millimeter of upper sieve, add "+" number before the mesh millimeter of lower screen, represent that material grade is less than upper sieve mesh size, is greater than lower screen hole dimension, for the material grade that bottom one deck screen cloth passes through, add "-" number with before screen cloth mesh millimeter, the proportion of composing of each grade represents with weight percent;

2) calculating of theoretical formula size composition reasonableness R value, using the upper sieve mesh size millimeter of each grade as independent variable(s), represents with X, the weight percentage composition being less than or equal to upper sieve mesh of each grade is carried out cumulative addition, as dependent variable, represent with Y, obtain one group of data pair about X and Y, the value that data are right represents with Xi and Yi, the number that data are right represents with n, i=1,2,, n;

3) Graphite Electrodes theory formula size composition reasonableness is determined by following formula according to R value:

$R=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X}_i{Y}_i-\frac{1}{n}\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X}_i\right)\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y}_i\right)}{\sqrt{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X_i}^2-\frac{1}{n}{\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{X}_i\right)}^2}\&CenterDot;\sqrt{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y_i}^2-\frac{1}{n}{\left(\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{Y}_i\right)}^2}}$

Stagnation point=(1+0.618) ÷ 2=0.809 of R value, when R >=0.809, the size composition of theoretical formula has reasonableness, can be used in Graphite Electrodes and produces; As R < 0.809, the size composition of theoretical formula does not have reasonableness, can not be used for Graphite Electrodes and produce.