CN101871897A - Method for determining kneading temperature of graphite electrode carbon paste - Google Patents

Abstract

The invention discloses a method for determining the kneading temperature of graphite electrode carbon paste, which is characterized by comprising the following steps: testing the coking value Fc and the physical and chemical indicator of a softening point Sp of asphalt used as binder; establishing a mathematic empirical formula of kneading temperature t of the graphite electrode carbon paste; determining ranges of the upper limit and the lower limit of the kneading temperature of the graphite electrode carbon paste by calculation; determining another mathematic empirical formula of the kneading temperature t of the graphite electrode carbon paste according to the dynamic viscosity testing value of the asphalt in different conditions; and determining the ranges of the upper limit and the lower limit of the kneading temperature of graphite electrode carbon paste by calculation. The method of the invention has the advantages of scientificalness and reasonableness, easily and accurately determined kneading temperature of the graphite electrode carbon paste, small amount of pilot production compression product, low green rejection rate, high kneading process efficiency and good green electrode quality and the like.

Description

Definite method of kneading temperature of graphite electrode carbon paste

Technical field

The present invention is definite method of kneading temperature of graphite electrode carbon paste.

Background technology

Determine that carbon paste kneading temperature mainly is according to production practical experience, thickener mecystasis during graphite electrode articles is produced at present, green body extrusion pressure, carry out Comprehensive Assessment with reference to indexs such as asphalt softening point, β resin content, volatile matter, kinetic viscosity values, pass through the exploratory production die mould of a very long time like this, generally need 500～800 tons of green article of exploratory die mould, the kneading temperature of thickener need progressively be groped summing up experience, could finally decide.

This groping property trial production die mould will certainly cause a large amount of green compact waste products, and has delayed the production cycle, has improved enterprise's production cost.So far, do not see that as yet kneading temperature of graphite electrode carbon paste is by being converted into the reported in literature and the practical application of the definite method of calculated with mathematical model.

Summary of the invention

The objective of the invention is, on the basis of a present general inventive concept, provide scientific and reasonable, kneading temperature of graphite electrode carbon paste is accurately determined easily, trial production die mould product quantity is few, the green compact rejection rate is low, two kinds of definite methods of kneading process efficient height, the measured kneading temperature of graphite electrode carbon paste of green electrode matter.

The object of the present invention is achieved like this:

A kind of definite method of kneading temperature of graphite electrode carbon paste is characterized in that: it comprises tests toluene insolubles TI, quinoline insolubles QI, moisture W, volatile matter V, ash content A, β resin, coking value Fc and softening point Sp physical and chemical index as the pitch of cementing agent; Set up the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t ₁With kneading temperature upper limit t ₂The mathematic(al) experience formula is respectively:

Kneading temperature lower limit t ₁=478.7Fc+0.172Sp-110 ... (1)

Kneading temperature upper limit t ₂=478.7Fc+0.172Sp-102 ... (2)

Respectively substitution (1) formula and (2) formula are determined the scope of kneading temperature of graphite electrode carbon paste t according to the asphalt coking value Fc of actual measurement and softening point Sp physical and chemical index.

Definite method of another kind of kneading temperature of graphite electrode carbon paste, it is characterized in that: it comprises according to the kinetic viscosity test value of pitch under different temperatures as cementing agent, the milli handkerchief. second mPa.s, determine that the mathematic(al) experience formula of kneading temperature of graphite electrode carbon paste t is:

$t=\sqrt[B]{\frac{{0.002e}^A}{\mathrm{\λ}}}......\left(3\right)$

In the formula, the span 1.05～0.58 of empirical parameter λ, viscosity parameter B, A are calculated and are tried to achieve by (4) formula, (5) formula respectively according to the actual test result of asphalt viscosity, and e is an irrational number, e=2.718281828 ...,

The computing formula of viscosity parameter B is:

$B=-\frac{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\η}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\η}\÷n}{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\δ}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\δ}\÷n}......\left(4\right)$

The computing formula of viscosity parameter A is:

$A=\frac{\mathrm{\Σ}\ln \mathrm{\η}}{n}+\frac{\mathrm{\Σ}\ln \mathrm{\δ}}{n}\×B......\left(5\right)$

In the formula: δ represents observed temperature, and η represents to survey kinetic viscosity, and n represents the point for measuring temperature number, with calculated value substitution (3) formula of (4) formula, (5) formula, learns from else's experience and tests parameter lambda=1.05, determines the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t ₁, learn from else's experience and test parameter lambda=0.58, determine the kneading temperature upper limit t of kneading temperature of graphite electrode carbon paste t ₂Thereby, the scope of definite kneading temperature of graphite electrode carbon paste t.

Definite method of kneading temperature of graphite electrode carbon paste of the present invention, be on the basis of a present general inventive concept, two kinds of definite methods of kneading temperature of graphite electrode carbon paste are provided, a kind of is the coking value Fc and the softening point Sp physical and chemical index of surveying according to as the pitch of cementing agent, obtain a mathematics empirical model, another kind is according to the kinetic viscosity test value of pitch under different temperatures as cementing agent, obtain another mathematic(al) experience model, adopt Calculation Method to determine thickener kneading temperature scope according to the mathematic(al) experience model respectively again, thereby the computational problem that the kneading temperature of graphite electrode carbon paste problem is converted into mathematical model solves, have scientific and reasonable, kneading temperature of graphite electrode carbon paste is accurately determined easily, trial production die mould product quantity is few, the green compact rejection rate is low, kneading process efficient height, advantages such as the green electrode quality is good.

Embodiment

Embodiment 1: with this steel mid-temperature pitch is example, determines the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t with definite method of first kind of kneading temperature of graphite electrode carbon paste of the present invention ₁With kneading temperature upper limit t ₂As follows: this steel pitch test result is: toluene insolubles TI=16.90%, quinoline insolubles QI=4.32%, moisture W=0.14%, volatile matter V=64.31%, ash content A=0.13%, β resin=12.58%, coking value Fc=51.62%, softening point Sp=87.2 ℃.With coking value Fc and softening point Sp difference substitution (1) formula and (2) formula;

(1) formula obtains: kneading temperature lower limit t ₁152 ℃ of=478.7Fc+0.172Sp-110=478.7 * 51.62%+0.172 * 87.2-110 ≈;

(2) formula obtains: kneading temperature upper limit t ₂160 ℃ of=478.7Fc+0.172Sp-102=478.7 * 51.62%+0.172 * 87.2-102 ≈.

This steel mid-temperature pitch is the commercially available prod that Benxi sheet material incorporated company of iron and steel Group Co.,Ltd produces.

Embodiment 2: with middle temperature modified pitch is example, determines the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t with definite method of first kind of kneading temperature of graphite electrode carbon paste of the present invention ₁With kneading temperature upper limit t ₂As follows: middle temperature modified pitch test result is: toluene insolubles TI=22.96%, quinoline insolubles QI=7.38%, moisture W=0.09%, volatile matter V=60.32%, ash content A=0.10%, β resin=15.58%, coking value Fc=53.41%, softening point Sp=88.6 ℃.With coking value Fc and softening point Sp difference substitution (1) formula and (2) formula;

(1) formula obtains: kneading temperature lower limit t ₁161 ℃ of=478.7Fc+0.172Sp-110=478.7 * 53.41%+0.172 * 88.6-110 ≈;

(2) formula obtains: kneading temperature upper limit t ₂169 ℃ of=478.7Fc+0.172Sp-102=478.7 * 53.41%+0.172 * 88.6-102 ≈.

Definite method of second kind of kneading temperature of graphite electrode carbon paste of the present invention is according to the kinetic viscosity test value of pitch under different temperatures as cementing agent, the milli handkerchief. second mPa.s, determine that the mathematic(al) experience formula of kneading temperature of graphite electrode carbon paste t is:

$t=\sqrt[B]{\frac{{0.002e}^A}{\mathrm{\λ}}}......\left(3\right)$

In the formula, the span 1.05～0.58 of empirical parameter λ, viscosity parameter B, A are calculated and are tried to achieve by (4) formula, (5) formula respectively according to the actual test result of asphalt viscosity, and e is an irrational number, e=2.718281828 ...,

The computing formula of viscosity parameter B is:

$B=-\frac{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\η}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\η}\÷n}{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\δ}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\δ}\÷n}......\left(4\right)$

The computing formula of viscosity parameter A is:

$A=\frac{\mathrm{\Σ}\ln \mathrm{\η}}{n}+\frac{\mathrm{\Σ}\ln \mathrm{\δ}}{n}\×B......\left(5\right)$

In the formula: δ represents observed temperature, 120～200 ℃ of test asphalt temperature scopes, and 10 ℃ of temperature intervals, η represents to survey kinetic viscosity, and n represents the point for measuring temperature number,

The value of viscosity parameter A and B should keep 3 decimal digits at least, with calculated value substitution (3) formula of (4) formula, (5) formula, learns from else's experience and tests parameter lambda=1.05, determines the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t ₁, learn from else's experience and test parameter lambda=0.58, determine the kneading temperature upper limit t of kneading temperature of graphite electrode carbon paste t ₂Thereby, the scope of definite kneading temperature of graphite electrode carbon paste t.

The kinetic viscosity η measured value of two kinds of pitches of table 1

Embodiment 3: they are example still with this steel mid-temperature pitch, and with definite method of second kind of kneading temperature of graphite electrode carbon paste of the present invention, point for measuring temperature number n=6 of this steel mid-temperature pitch,

According to formula (3), formula (4) calculate viscosity parameter B, viscosity parameter A is:

$B=-\frac{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\η}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\η}\÷n}{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\δ}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\δ}\÷n}=-\frac{200.55984-29.81828\×40.54072\÷6}{148.27308-29.81828\×29.81828\÷6}\≈10.80392;$

$A=\frac{\mathrm{\Σ}\ln \mathrm{\η}}{n}+\frac{\mathrm{\Σ}\ln \mathrm{\δ}}{n}\×B=\frac{40.54072}{6}+\frac{29.81828}{6}\×10.80392\≈60.44917;$

Embodiment 4: they are example still with middle temperature modified pitch, and with definite method of second kind of kneading temperature of graphite electrode carbon paste of the present invention, point for measuring temperature number n=7 of middle temperature modified pitch,

According to formula (3), formula (4) can calculate viscosity parameter B, viscosity parameter A is:

$B=-\frac{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\η}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\η}\÷n}{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\δ}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\δ}\÷n}=-\frac{245.70561-35.01123\×49.39991\÷7}{175.23988-35.01123\×35.01123\÷7}\≈10.76490;$

$A=\frac{\mathrm{\Σ}\ln \mathrm{\η}}{n}+\frac{\mathrm{\Σ}\ln \mathrm{\δ}}{n}\×B=\frac{49.39991}{7}+\frac{35.01123}{7}\×10.76490\≈60.89890;$

In warm modified pitch be the commercially available prod that the sharp chemical industry of Shijiazhuang City moral company limited produces.

Three parameter values in table 2 formula (3)

Parameter in the formula (3)	This steel mid-temperature pitch	In warm modified pitch
			Viscosity parameter B	??10.80392	??10.76490
Viscosity parameter A	??60.44917	??60.89890
			Empirical parameter λ	??1.05～0.58	??1.05～0.58

Embodiment 3: for this steel mid-temperature pitch, get λ=1.05, and viscosity parameter B=10.80392, viscosity parameter A=60.44917 substitution (3) formula obtains the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t ₁,

The kneading temperature lower limit

Get λ=0.58, viscosity parameter B=10.80392, viscosity parameter A=60.44917 substitution (3) formula obtains the kneading temperature upper limit t of kneading temperature of graphite electrode carbon paste t ₂

The kneading temperature upper limit

Embodiment 4: for middle temperature modified pitch, and kneading temperature lower limit t ₁, get λ=1.05, viscosity parameter B=10.76490, viscosity parameter A=60.89890 substitution (3) formula obtains

The kneading temperature lower limit

Get λ=0.58, viscosity parameter B=10.76490, viscosity parameter A=60.89890 substitution (3) formula obtains

The kneading temperature upper limit

Two kinds of calculated with mathematical model result contrasts of kneading temperature of graphite electrode carbon paste

The calculated with mathematical model value of table 3 kneading temperature of graphite electrode carbon paste (℃)

Above two kinds of methods of the present invention all can be determined kneading temperature of graphite electrode carbon paste by calculated with mathematical model according to the physical and chemical index of pitch.The scope of the kneading temperature of graphite electrode carbon paste t that calculate formula (1), (2) contrast equation (3), (4) and (5) is of slight difference.

From this steel mid-temperature pitch and among the embodiment of warm modified pitch, though two kinds of asphalt softening points are basic identical, because the coking value difference, carbon paste kneading temperature also can be different.According to top two kinds of pitches calculated with mathematical model complete realistic condition of production of its calculated value of carbon paste kneading temperature of coming out separately.The present invention does not limit to this embodiment, the mathematical model that the same the present invention of being suitable for sets up of determining for the carbon paste kneading temperature of other different types of pitch binders, only need to test coking value Fc, softening point Sp, the kinetic viscosity η of its pitch, can accurately calculate the kneading temperature of the carbon paste of graphite electrode.

Physics and chemistry explanation of nouns involved in the present invention is as follows:

Softening point Sp: the pitch sample of certain volume, heat the temperature that sample is softening when hanging down to certain distance, unit ℃ under the load of constant weight.

Coking value Fc: the pitch sample of certain mass, heating in 550 ± 10 ℃ high temperature furnace, weighing cinder then, the cinder quality accounts for the number percent of sample mass.

Kinetic viscosity η: a kind of method for expressing of eu-bitumen internal friction size.Asphalt viscosity during generally with different temperatures the moment of torsion for wherein rotor record the mPa.s of unit through converting.

Toluene insolubles TI: the pitch sample of certain mass carries out extracting with toluene, and the quality of its residue accounts for the percentage of original sample quality.

Quinoline insolubles QI: the pitch sample of certain mass, to dissolve at a certain temperature with quinoline, the quality of its insolubles accounts for the percentage of original sample quality.

The β resin content: toluene insolubles deducts quinoline insolubles.

Volatile matter V: formulating under the temperature, in the stipulated time, with the heating of pitch sample, the volatile matter quality accounts for the number percent of sample size.

Claims (2)

1. definite method of a kneading temperature of graphite electrode carbon paste is characterized in that: it comprises tests toluene insolubles TI, quinoline insolubles QI, moisture W, volatile matter V, ash content A, β resin, coking value Fc and softening point Sp physical and chemical index as the pitch of cementing agent; Set up the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t ₁With kneading temperature upper limit t ₂The mathematic(al) experience formula is respectively:

Kneading temperature lower limit t ₁=478.7Fc+0.172Sp-110 ... (1)

Kneading temperature upper limit t ₂=478.7Fc+0.172Sp-102 ... (2)

Respectively substitution (1) formula and (2) formula are determined the scope of kneading temperature of graphite electrode carbon paste t according to the asphalt coking value Fc of actual measurement and softening point Sp physical and chemical index.

2. definite method of a kneading temperature of graphite electrode carbon paste, it is characterized in that: it comprises according to the kinetic viscosity test value of pitch under different temperatures as cementing agent, the milli handkerchief. second mPa.s, determine that the mathematic(al) experience formula of kneading temperature of graphite electrode carbon paste t is:

$t=\sqrt[B]{\frac{{0.002e}^A}{\mathrm{\λ}}}......\left(3\right)$

In the formula, the span 1.05～0.58 of empirical parameter λ, viscosity parameter B, A are calculated and are tried to achieve by (4) formula, (5) formula respectively according to the actual test result of pitch kinetic viscosity, and e is an irrational number, e=2.718281828 ...,

The computing formula of viscosity parameter B is:

$B=-\frac{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\η}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\η}\÷n}{\mathrm{\Σ}\ln \mathrm{\δ}\ln \mathrm{\δ}-\mathrm{\Σ}\ln \mathrm{\δ\Σ}\ln \mathrm{\δ}\÷n}......\left(4\right)$

The computing formula of viscosity parameter A is:

$A=\frac{\mathrm{\Σ}\ln \mathrm{\η}}{n}+\frac{\mathrm{\Σ}\ln \mathrm{\δ}}{n}\×B......\left(5\right)$

In the formula: δ represents observed temperature, and η represents to survey kinetic viscosity, and n represents the point for measuring temperature number, with calculated value substitution (3) formula of (4) formula, (5) formula, learns from else's experience and tests parameter lambda=1.05, determines the kneading temperature lower limit t of kneading temperature of graphite electrode carbon paste t ₁, learn from else's experience and test parameter lambda=0.58, determine the kneading temperature upper limit t of kneading temperature of graphite electrode carbon paste t ₂Thereby, the scope of definite kneading temperature of graphite electrode carbon paste t.