Metallurgy is burnt

1, the coke is defined

　The bituminous coal is heated to 950-1050 degrees Centigrade, make coke finally such stages as dry, hot solving, melting, cohering, solidification, shrinking,etc. Dr.eye: on terms that isolated air, this course lets the high temperature coke ( High-temperature the universe heat up in a steamer) . The coke coked by the high temperature and got is used in the blast furnace and smelt, cast melting kindly. The coke oven coal gas after retrieving, purifying emerging is the fuel of the high calorific value in the coking course, it is important industrial raw materials of organic synthesis.

　　Metallurgy blast furnace burnt casting burnt, ferroalloy burnt and coloured metal smelt spend a burnt one referred to as. Because more than 90% of the metallurgy is used in blast furnace iron-smelting burntly, metallurgy is burnt that often call the blast furnace burntly.

　　It is the special-purpose coke that melted the iron with the cupola furnace to cast burntly. It is the main fuel that the cupola furnace melted the iron to cast burntly. Function its to melt furnace charge and make molten iron to be overheated, support material post keep a good one their getting ventilative. So cast burnt to should possess pieces of degrees of heavy, responsivity low, rate little having is it bludgon broken intensity, person who sucks dust, sulphur content low grade characteristic into to resisting enough air vent.

2, the coke is distributed

　　 By the look of distribution situation of output of coke of our country, of our country coking enterprise region distribute unevenly, distribute to North China, East China and the Northeast mainly.
3, coke use

The coke is used in blast furnace iron-smelting and blast furnace used in such nonferrous metals as the copper, lead, zinc, titanium, antimony, mercury,etc. to smelt mainly, a case of reducing agent, generating heat on pharmaceutical and material post skeleton function. The iron-smelting blast furnace replaces the charcoal with coke, it is a great milestone in the metallurgical history to establish the foundation for the maximization of the modern blast furnace. In order to make the blast furnace operate and reach the economic indicator of better technology, smelt and use the coke (metallurgy is burnt) Must have proper chemical property and physical property, including smelt the hot nature in the course. The coke is used in iron-smelting and coloured metal smelt except that in a large amount ( Metallurgy is burnt) Outside, still used in casting, chemical industry, carbide and ferroalloy, its quality requirement is different to some extent. Such as is it use burnt, require grain size heavy, air vent rate low, high with low sulphur content fixed carbon generally to cast; Chemical gasification is used burntly, can't require tightly the intensity, but require the responsivity is good, the gray point is relatively high; The carbide is produced by demanding to try one's best to raise the content of fixed carbon burntly.

4, the physical property of the coke
The coke physical property including coke is sifted and divided into groups, the coke distributes the density, very relative density of coke, the coke looks at the relative density, coke air vent rate, coke specific heat holds, temperature, hot coefficient of expansion of coke, the shrinking rate of coke, resistivity and burnt of coke that the thermal conductance rate of coke, hot stress of coke, coke catch fire
The physical property and its mechanical intensity and hot intensity and chemical property of normal atmospheric temperature of the coke are closely related with. The main physical property of the coke is as follows:

　　The real density is 1.8-1.95g/cm3;

Regard density as 0.88-1.08g/cm3;

　The air vent rate is 35-55%;
The density is 400-500kg/m3 to break up;
　Average specific heat holds for 0.808kj/ ( kg k) (100 degrees Centigrade) ,1.465kj/( kg k) (1000 degrees Centigrade) ;

The thermal conductance rate is 2.64kj/ ( m h k) (normal atmospheric temperature) ,6.91kg/( m h k) (900 degrees Centigrade) ;

　　Temperature that catch fire ( In the air) It is 450-650 degrees Centigrade;

　The low calorific value of the dry ashless base is 30-32kj/g;

It is 0.6-0.8m2/g than the surface area.

5, the responsivity of the coke and intensity after the response

Such ability to carry on chemical reaction as the coke responsivity and carbon dioxide, oxygen and vapor,etc., the intensity refers to the coke after reacting and resists cracked ability wearing and tearing under mechanical force and hot stress function after the coke reacts. The coke is in blast furnace iron-smelting, cast melting in the iron and fixed bed gasification course, the chemical reaction take place with the carbon dioxide, oxygen and vapor. Because burnt there are laws similar to response of the carbon dioxide with responses of oxygen and vapor, so most countries evaluate the coke responsivity with the response characteristic among the coke and carbon dioxide.
　　 　　China's standard (GB/T4000-1996) Have stipulated the coke responsivity and test method of the intensity after the response. Its method is to make the coke not react with the carbon dioxide under the high temperature, then the weightless rate of coke and mechanical intensity after determining and reacting. Whether coke responsivity CRI and repeated r, intensity of CSR can't exceed the following number value after the response.
CRIr≤2.4%　　　　　　　　　　　
CSR：≤3.2%
Coke responsivity and result of the test of the intensity after the response fetch the arithmetic mean of the parallel result of the test.

6, the quality indicator of the coke

Coke high-temperature solid result that the universe heated up in a steamer, the backbone is a carbon, have crackle and irregular hole spore's structure body (or the hole spore's porous body) . The amount of the crackle influences the dynamics of the coke and resists the garrulous intensity directly, its indicator is generally with the crackle degree (refer to the amount of the length of crackle in unit's volume coke) Come to weigh. Weigh hole indicator, spore of structure mainly use the air vent rate ( Only the volume of air vent of coke takes the percentage of the total volume) To show, it influences the responsivity and intensity of the coke. Coke of different uses, require the indicator of air vent rate differently, it is in 40-45 that the burnt air vent rate of general metallurgy is required, cast and require burntly that exports and requires it about 30% burntly in 35- 40. Coke usually with resist garrulous intensity and wear-resisting intensity two indicator express intensity. To resist garrulous intensity mean coke can is it receive outside shock power than along crackle or defect office broken ability of structure to resist coke, express with M40 value; Does the wear-resisting intensity of the coke mean the coke can be resisted and rubed outsidely? Strength and no ability of forming the piece or the powder of the surface glass will emerging, express with M10 value. Crackle degree of the coke influences it to resist garrulous intensity M40 value, the hole spore's structure of the coke influences the wear-resisting intensity M10 value. M40 and survey, M10 of value method a lot of, our country adopt tribute, rice of German, transfer method that drum tests to more.
7, the appraisal of coke quality

　　1, the sulphur content of the coke: The sulphur is one of the harmful impurity that the pig iron smelts, it makes pig iron quality reduce. It is the wasted product that the content of sulphur is greater than 0.07% in the steel-making pig iron. Bring into the sulphur in the stove and have 11% to come from the ore by the furnace charge of blast furnace; 3.5% comes from the lime stone; 82.5% comes from the coke, so the coke is the main source of the sulphur in the furnace charge. The level of the coke sulphur content influences the iron-smelting production of the blast furnace directly. As the coke sulphur content is greater than 1.6%, the sulfur increases by 0.1% each time, the consumption of coke increases by 1.8%, the joining amount of lime stone increases by 3.7%, the joining amount of ore increases output of blast furnace 0.3% to reduce by 1.5 2.0%. The sulphur content with burnt metallurgy stipulates that is not greater than 1%, the burnt sulphur content of the metallurgy that the large-and-middle-scale blast furnace uses is smaller than 0.4 0.7%.

　2, the phosphorus of the coke is divided: The burnt phosphorus content of the metallurgy used in iron-smelting should be under 0.02 0.03%.

　3, including the dust amount of the coke: The influence that the dust amount of including of the coke smelts to the blast furnace is very apparent. The coke includes the dust amount to increase by 1%, coke consumption increases by 2 2.5%, the reducing including gray quantity of coke is very essential.
4, the volatile matter of the coke: Can judge the coke maturity according to the content of volatile matter of the coke. If the volatile matter is greater than 1.5%, show that grows burntly; The volatile matter is smaller than 0.5 0.7%, show that goes too far, generally ripe metallurgy volatilizes and is divided into about 1% burntly.
5, the moisture of the coke: The moisture will make the coke measure to fluctuate inaccurately, thus cause the condition of the stove to fluctuate. In addition, the coke moisture will make M04 on the high side to improve, M10 is on the low side, give and transfer to the drum indicator and bring the error.

Whether 6, sieve of the coke divide into groups. The grain size of the coke is very important too in the blast furnace is smelted. Our country was to the demand of grain size of coke in the past: To the big coke oven ( 1300 2000 square meters) The grain size of coke is greater than 40 mm. The grain size of medium and small blast furnace coke is greater than 25 mm.. But the tests of some steel factories indicate at present, the grain size of coke is good in 40 25 mm.. The coke greater than 80 mm. wants whole one, make its grain size range not change much. Coke is each and one in this way, the space is great, obstruction is small, the condition of the stove runs well.